Social media, like all things on the internet, can provide great benefits or be a total cesspool depending how it is managed. On the plus side, a teacher can funnel new discoveries directly to students. This is much preferable to waiting a few years for that to be published in textbooks. On the downside there are the usual trolls waiting for you. And obviously, we don’t want the classroom to resemble a website comments section. For this post, I’ll focus on Twitter and Facebook.
I was reluctant to sign up on Twitter with its 140 character limitations. However, I teach astronomy, and NASA is a Twitter machine. This is particularity true with ongoing missions. Once a mission has ended, but the data is still being processed, NASA seems to prefer Facebook to make those announcements. In Twitter culture, there is an emphasis on acquiring large amounts of followers. Unless you work in mass media, I would recommend looking for high quality of interaction over quantity. The Twitter landscape is populated by trolls and bot accounts. Target certain accounts that are subject related and be quick to use the block feature to prevent an interloper from ruining the experience. If Twitter is being used in a class, using a private account may be a good option.
Twitter is at its best when researchers are disseminating and reviewing results. At times, you may get to see the scientific process at work when scientists debate their results. In the class, this can be a demonstration of the dynamics of scientific discovery. Sometimes it’s messy! It can be used to display professionalism when researches volley back and forth over the meaning of their data. It can also be used to demonstrate that even professionals can stumble and personalize their arguments. In science, its the argument, not the person, that wins the day. Used wisely, Twitter can be a useful mechanism to bring current research results into the class.
Facebook is a different animal. With greater privacy settings, it is easier to contain the trolling element without going completely private. Once a mission has ended, NASA’s twitter accounts tend to go silent while further discoveries are announced on their Facebook accounts. For example, after the Messenger mission ended, the discovery that Mercury was shrinking was released on Facebook but not on Twitter. For astronomy, this makes Facebook a key supplement to Twitter. Unlike Twitter, Facebook does not have a character limit allowing for more descriptive posts. Also unlike Twitter, you are not likely to see scientific debates on Facebook. However, Facebook has a higher quality interface for images which is especially helpful for astronomy. To start off, below are some links.
For Twitter, you do not need an account to access a public Twitter feed. The blue check marks next to an account name verifies this is a legit feed.
Of course, as you explore various Twitter accounts you’ll find others that strike your fancy. Like Twitter, Facebook allows accounts to verify themselves as legit with a blue check mark. Facebook requires an account to view other feeds. Some good Facebook feeds to start with:
Over a thousand years ago, the Silk Road served to transport knowledge and ideas between Central Asia, China, India, and Western Europe. The internet serves the same purpose today and social media is a key component. With a little experience and time to manage it, social media can play a constructive role in the classroom.
In high school, students are typically introduced to the three basic particles that constitute atoms, that being, protons, neutrons, and electrons. Unless you decide to take physics in college, education of the atom typically stops there. That gives the impression that these particles are the smallest bits of matter to be found. Both protons and neutrons consist of even smaller sub-atomic particles. The electron cannot be broken down any further. However, unlike the simple models taught in high school, it is not a particle that orbits the nucleus like planets orbiting stars.
Quantum mechanics dictate the properties of sub-atomic particles which behave quite differently from the large objects we can see. As a result, their behavior can be counter-intuitive as our eyesight is not capable of resolving these particles. In the quantum world, particles can pop in and out of existence and consequently, tunnel through barriers in a manner large objects cannot. The Standard Model guides our understanding of this realm. This model predicts dozens of quantum particles and configurations – the subatomic jungle. This post will not be a comprehensive going over of that as that would require a Modern Physics course, but will serve to stretch the bounds of your knowledge beyond the simple atomic model.
Protons and neutrons make up the nucleus of an atom. Protons have a positive electrical charge and neutrons have no charge. Both protons and neutrons are made of quarks which have a charge that comes in thirds. Up quarks have a charge of 2/3 while down quarks have a charge of – 1/3. It takes three quarks to make a proton or neutron. In the case of a proton, there are two up quarks and one down quark (the charge is 2/3 + 2/3 – 1/3 = 1). The neutron is made of one up quark and two down quarks (the charge being 2/3 – 1/3 – 1/3 = 0). Besides the difference in charge, there is a slight difference in mass between protons and neutrons.
Neutrons are slightly more massive than protons. If the neutron resides in the nucleus, it is stable. If it is a free-floating particle, the neutron eventually decays into a proton. During this process, known as beta decay, an electron and an antineutrino is released. Beta decay often occurs in nuclear reactors. An antineutrino is the antimatter version of a neutrino. Neither an antineutrino or a neutrino have electrical charge and their mass is close to zero. Neutrinos are produced in the nuclear fusion of stars including the Sun. In fact, each second, tens of billions of neutrinos pass through your body. These particles interact very weakly with matter and it requires very complex instruments to detect them.
It can take many thousands, and according to some estimates, millions of years for a light photon created in the Sun’s core to reach the solar surface and begin its journey in space. As neutrino’s interact very weakly with matter, it only takes a few seconds to reach the solar surface. Thus, the study of solar neutrinos can provide clues pertaining to the current state of the solar core. Of course, this same property makes it very difficult to detect neutrinos and require specialized instruments. One such facility is the SNOLAB near Sudbury, Ontario. The detectors are located 2,000 meters below the surface to shield it from cosmic ray noise. This is similar to locating a telescope in a dark area to prevent noise from human made light. Neutrinos can also give an early detection method for supernovae. As a supernova will release neutrinos before light, detecting these neutrinos can alert astronomers to turn their telescopes to observe the moment light is released from these events.
Like neutrinos, electrons are a fundamental particle. Unlike neutrinos, electrons have a negative charge. In neutral atoms, the negative charge of electrons offsets the positive charge of an equal amount of protons. In high school, we are taught the model that electrons are point-like particles orbiting the nucleus. This is a simplified model to start students off in understanding the atom and has provided the misconception that electrons are similar to miniaturized planets orbiting the Sun. The reality is more complex. Electrons are smeared into a cloud encircling the nucleus. The cloud is a probability curve in which the electron exists in all its possible states. Bizarre? Welcome to the quantum world.
How would this translate to the large-scale world we can see? Think of a dice in a box. Shake the box, which number of the dice is facing up? In the quantum world, all six configurations exist simultaneously in the box. That is, until you open the box and the probability curve collapses to the configuration observed.
That’s how Niels Bohr saw it and it is referred to as the Copenhagen Interpretation. To some, this explanation was unsatisfactory and led to Schrödinger’s cat. Erwin Schrödinger proposed a thought experiment where a cat is placed in a box with a cyanide capsule that would be triggered when a Geiger counter detected a radioactive decay. The decay had a 50% probability of occurring. Thus, in the quantum world, the atom exists in both states-one where it had decayed and released radioactivity and the other where it had not. But what about the cat? Did it too exist in two states, one dead and one alive? Worry not, no one has tried this experiment. It was Schrödinger’s way of pointing out the inconsistencies between quantum mechanics of the atom and the law of relativity which governs how large objects behave. Others, such as Hugh Everett III, sought another explanation.
In his 1957 doctoral thesis, Everett argued that the universe splits with each possible action. Thus, in the dice example, once you shake the box, the universe splits into six different universes. Each universe has the dice with a different number facing up. This removes the need for an observer to collapse the probability wave. It’s a fascinating proposal, as this would mean there exists separate universes for each course of action you could have taken in your life. While many physicists are very enthusiastic about Everett’s work, they have not yet devised a way to test it experimentally as we are unable to observe other universes. Unless such a way is devised, for now, we have to treat it as a very interesting hypothesis. The same can not be said about the Higgs boson.
Unlike the particles above that make up matter, bosons transmit the basic forces of nature. There are four of these forces, electromagnetism, weak-nuclear, strong-nuclear, and gravity. Photons are particles of light that transmit electromagnetic force. W and Z bosons transmit the weak-nuclear force that causes radioactive decay. Gluons transmits the strong nuclear force that binds atomic nuclei together. It is this force that is released in nuclear weapons. Gravitons are a speculative boson that would transmit gravity. To date, we do not have a quantum theory that explains gravity on an atomic scale. And then there is the Higgs boson, the so-called God particle.
The God particle is a misnomer. Leon Lederman, who was awarded a Nobel in 1988, referred to the Higgs boson as the Goddamn particle as it was so difficult to detect. Lerderman’s popular book on nuclear physics published in the early 1990’s was to be titled after the original moniker, but the publisher shortened it to The God Particle. While the Higgs boson has no religious connection, it is crucial as it imparts the property of mass in atoms. Mass is often confused with weight. Mass is constant whereas weight can change. If you travel to the Moon, your weight will be 1/6th what it is on Earth but your mass will remain the same. Weight is a measure of the force of gravity on a body whereas mass measures the amount of “stuff” in a body.
In 2012, it was announced the Higgs boson was discovered at the CERN Large Hadron Collider (LHC). The Higgs boson was predicted by the Standard Model and the evidence matched the prediction. CERN is a consortium of 22 nations and operates by the Swiss-France border. The LHC was opened in 2008 and is a 27 km ring that accelerates sub-atomic particles close to the speed of light via supercooled magnets. Besides its many discoveries in particle physics, CERN invented the World Wide Web in 1989 to disseminate its work. CERN allowed the World Wide Web to enter the public domain in 1993, making the internet boom of the 1990’s possible, not to mention, this blog.
The LHC is the world’s most powerful supercollider. The Superconducting Super Collider (SSC) that was being built in Texas during the early 1990’s would have dwarfed the LHC. The SSC would have been a 87 km ring and three times as powerful as the LHC. Construction on the SSC was halted in 1993. Several factors conspired to do in the SSC, among them the economy, politics, and cost overruns. The US economy entered into a recession during the early 1990’s prompting the federal government to look into cost cutting. Then there was Texas senator Phil Graham, who brought the bacon back to Texas but delighted in nixing projects in other states. Cancelling SSC was a way of returning the favor. At the time of cancellation, over $2 billion had been spent and the project was running several billion dollars over its original estimate.
That the SSC had cost overruns is not a surprise. In any project where technology has to be invented to complete it, there is a large degree of uncertainty with costs. This is true of the space program as well. When entering the realm of the unknown, the economics of that kind of project are not really known until completion. The SSC site now lies abandoned, with over 20 km of tunnels dug. Had it been completed, it could have opened our knowledge of quantum physics in the same manner the Hubble did for astronomy. The largest American supercollider, the Tevatron at Fermilab in Illinois, was shut down in 2011 in the aftermath of the global financial crisis. The next generation of supercolliders is being built in China, set to begin construction in 2020, will be twice the size of the LHC. To date, there is no American proposal to match these efforts.
While the traces left behind in particle accelerators allow us to deduce the properties of sub-atomic particles, we are unable to see the particles themselves as they are much smaller than lightwaves. Using x-rays, which have shorter wavelengths, we can see atomic structure in crystallized lattices, but not the particles themselves. This gets even more problematic when it comes to string theory which posits sub-atomic particles consisting of strings with a length of 10–35 meters. Detecting this is beyond the capability of the LHC and while string theory is impressive in its mathematical formulation, it will remain a hypothesis until a means is found to experimentally verify their existence. For other properties of sub-atomic particles, we can look into the most extreme environments of the universe.
If a hydrogen atom were the size of Earth, the nucleus would only be a few hundred feet wide with the rest being electron orbitals. If that’s the case, why can’t we walk through walls? When atoms are compressed in a smaller volume, electrons are excited to higher energy states and create outward pressure. This pressure is what prevents you from walking through walls. It takes a lot of energy to compress atoms. In white dwarfs, gravity compresses matter to the point where all the available energy states are taken up by electrons. The intense gravity of a white dwarf, 100,000 times that of Earth, is offset by the outward pressure force created by the energized electrons. Neutron stars can compress matter even more than white dwarfs. Formed by the supernova explosion of high-mass stars, these objects crunch electrons and protons to form neutrons – hence neutron stars. A teaspoon of this material would weigh about a billion tons compared to 5.5 tons for a white dwarf.
The Sun, in about five billion years, will shed its outer layers and form a planetary nebula with a white dwarf at the core. In a few tens of thousands of years afterwards, the nebula will dissipate leaving the white dwarf. There is no longer any fusion process when a star becomes a white dwarf, its luminosity is caused by the initial core temperature of 100,000 C. It takes many billions of years for white dwarfs to cool down. In fact, more time than the current age of the universe of 13.8 billion years.
Understanding the nature of sub-atomic particles allows us to understand the ultimate fate of the Sun. It has also allowed us to make many technological advances. Transistors, lasers, semi-conductors all owe their existence to our understanding of the tiniest particles of the quantum world. The pure theoretical work of modern physicists in the first half of the 20th Century made possible the world we currently live in.
*Image on top is the remains of neutrino collision at CERN. The particle tracks represent electron-positron pairs recorded in the particle accelerator. Credit: CERN
The film Hidden Figures, while high in entertainment value, takes some liberties with history. That’s not unusual for the movie industry. For starters, the book the movie is based on is 270 pages. Taking the rule of thumb that a screenplay requires one page for one minute, meaning the screenplay for the movie clocks in around 120 pages, right there is a lot of cutting to do. The first 172 pages of the book covers ground before NASA was founded. I suspect the movie pushed these events into the NASA era as the public is familiar with NASA, but not its predecessor NACA (National Advisory Committee for Aeronautics). Consequently, the movie misses out on World War II being a key trigger of the Civil Rights movement in and beyond NASA.
NACA existed from 1915 until 1958 when it was folded into NASA. NACA wind tunnels and research facilities played a crucial role in advancing aviation from propeller to jet engines and towards the birth of the space age. As the threat of war became imminent in 1939, NACA’s Langley facilities received publicity from Life Magazine as America needed to upgrade its aviation research. The war would also change the American economy from one that endured double-digit unemployment from the start of the Great Depression in 1930 to a high pressure economy with severe labor shortages. This shortage caused wartime employers to think out of the box when it came to traditional hiring practices.
The unemployment rate dropped from 14.6% in 1940 to a record low 1.2% in 1944. Below are the number of jobs created each month during the war. In 1942, 3.8 million new jobs were created. To put this in perspective, with a much larger workforce, 2 million jobs were created in 2016.
The story of Rosie the Riveter is well-known as millions of new job opportunities opened up for women in war production. What is not as well-known are the opportunities this opened up for African-Americans who beforehand were routinely discriminated in all but a narrow range of jobs. In the case of the women in Hidden Figures, they typically would have taken teaching jobs in a segregated black school. With the war ramping up the need for aviation research at Langley, opportunity came knocking for those who ordinarily would not have gotten it.
Located in Virginia, Langley was segregated during World War II. Women were employed as computers to handle what was considered the drudgery of mathematical calculations. Prior to World War II, America would demobilize after a war and Langley would have laid off many of its employees. However, with the upcoming Cold War, much of the workforce stayed on. And once women and African-Americans got the taste of opportunity, they were hungry for more. One can trace a direct line between the massive labor shortages of World War II, the beginnings of integration during the 1950’s, and the Civil Rights movement of the 1960’s.
The effort to integrate Langley occurred during the 1950’s before it became part of NASA. Integration at the base tended to go more smoothly than the surrounding region. While the computers were assigned to engineering groups, effectively ending the white and black computing departments, the state of Virginia was fiercely fighting school integration. Some school districts opted to shut down entirely while other towns opened all-white private academies to preserve segregation. At the university level, Virginia offered out-of-state scholarships to black students to keep the state university all white. These attempts to maintain segregation still lingered in the South when I moved to Texas in 1978. Some schools chose to classify each white student as gifted to enforce segregation with all-white advanced classes.
The book delves into this matter more so than the movie. When Mary Jackson wins court approval to attend an all-white school, the book notes her disappointment at the run down appearance of the building. The cost of needlessly operating duel school systems to maintain segregation was inefficient and lowered the educational experience for both white and black students. This is not restricted to the Deep South. I experienced integration in the Buffalo school system from 1976-77. It was no big deal for myself and my classmates but the same cannot be said for many of the parents. Over the next few decades, the schools re-segregated as whites moved out of the city into all white suburbs.
Metro areas which lack diversity tend to be economically stagnant. Young talent in fast growing industries favor diversity as that reduces the odds their talent will be left on the table. The longer Buffalo attempts to maintain segregation, the more difficulty it will have adapting to the new high-tech economy. The ability to adapt is a key feature in Hidden Figures and on an personal level, the main characters adaptation skills kept them gainfully employed at Langley for several decades.
The three decades from 1940-69 encompassed three distinct eras in aviation. First was the propeller planes of World War II, then the jet age of the Korean War, and finally rocket propulsion of the space age. As the book notes, America was slower than Europe to embrace rocket technology. Going back to when Robert Goddard was ridiculed by the New York Times for his proposals to use rockets for space exploration, America viewed this type of work as science fiction. The Jet Propulsion Laboratory was named as such to disguise its rocket research program. While the German V-2 brought rockets into reality, at Langley, up until Sputnik, the engineers were discouraged from working on space research.
When America was hurled into the space age in 1957, those at Langley who could not adapt were let go and missed out on the Apollo era. Those who did adapt, as demonstrated in both the book and the movie, stayed on until their retirements in the 1970’s and ’80’s. The retirement parties given were reflective of a different era in employee relations.
When I started working in the early 80’s, retirement parties were a common event. At Exxon, the Graphic Arts Department would put together a poster representing the retiree’s career. The last retirement party I’ve been to was in the early 90’s. In the private sector at least, very few people make it to voluntary retirement, usually getting let go before then. And the process is as impersonal as it can possibly be. The idea being that’s how Ayn Rand would have wanted it, or something. The current lack of social structure and churning of employees in the corporate world reduces productivity as job knowledge is chronically allowed to walk out the door.
The engineers at Langley were not prone to let talent lie fallow. The professional crew came from all parts of the country and had varying attitudes towards women and blacks in the workplace. It was one such engineer who allowed Mary Jackson to work in the air tunnel and eventually move up as an engineer. Another engineer convinced his superior to allow Katherine Johnson’s name as co-author on a research paper as “she was doing most of the work anyway.” The women at Langley were numerous enough to build an extensive support network which helped them advance. The African-American men not so much. They dealt with segregation via avoidance such as eating lunch in a black owned restaurant off the Langley premises to elude the segregated cafeteria. Unlike as depicted in the movie, the most egregious episodes of discrimination came from the locals who were mostly employed as technicians. One such example was a tech sabotaging a wind tunnel experiment run by a black engineer. The engineer’s manager chewed out the tech publicly to prevent another occurence.
What lessons can we take from this history? On an individual/company level, look at your employees talent and use it to the fullest for optimal performance. That means allowing for diversity in the workplace. To use an analogy, would major league baseball been better off without the talents of Henry Aaron and Willie Mays? We know the answer as teams like the Boston Red Sox and New York Yankees, who were slow to integrate, suffered long stretches of losing seasons in the 1960’s as a result. Also, adaptability is key for survival. The instinct to stand pat should be avoided. On a macro level, a policy of pushing for a high pressure economy can induce societal and economic change as employers are forced to innovate in their hiring practices. While we can’t restore the past to bring about positive results, we can at least take home the proper lessons of history.
*Image above is from Katherine Johnson’s first author credit. The full research paper can be found here. Another notable effort from Johnson is on the navigation for Solar System exploration which can be found here.
Most are aware the role carbon, specifically in carbon dioxide, plays in global warming. What is important is not to designate carbon as something inherently harmful. In fact, without carbon, life would not be possible. So lets take a look at carbon and how it fits into the big picture on Earth.
Carbon is created in the nuclear fusion of stars. When sun-like stars become red giants, their cores fuse helium and beryllium into carbon atoms. When a massive star goes supernova, the explosion disperses the matter created by that star into the universe and is recycled into new stars and planets. Remember the old song lyric, “We are stardust?” That is literally the case. The matter that makes up most of our bodies was produced in the fusion reaction of an ancient generation star.
So what is carbon? Lets take a look at the image below:
First, note the number of protons in the nucleus equals the number of electrons orbiting the nucleus. Protons have a positive charge and electrons have a negative charge. The fact that there are equal numbers of both means the atom is electrically neutral. Also, note that there are four electrons in the outside orbital shell. This shell can fit a total of eight electrons. Thus, the carbon atom can form molecules with other elements by sharing four electrons in the outer shell with the other element. Atoms like to have their outside shells filled, or as many a high school chemistry teacher has said, are “happy” when those outer shells are filled.
Carbon Based Life
The study of organic chemistry is often treated as a course onto itself. What is important to understand is that life on Earth is carbon based. The bonds that a carbon atom can form with hydrogen, oxygen, and nitrogen atoms make it the backbone of organic molecules that life consists of. Carbon atoms have the ability to form long complex chains of molecules to create carbohydrates, lipids, proteins, and nucleic acids (such as DNA).
Nature likes to recycle. As noted above, carbon was formed in stars and recycled in new stars. Carbon is recycled on Earth as well. Ever hear of the term fossil fuels? That is because the fuel we use is carbon based. And those carbon based fuels are extracted from the Earth. How did those carbon based fuels get there? From the dead remains of plant and animal life that existed on Earth millions of years ago.
Hydrocarbons
The fuel we use in our day-to-day lives are based on hydrocarbons. The term is derived from the molecular structure of these fuels based on molecules composed of carbon and hydrogen atoms. For example, natural gas is mostly methane which is a simple hydrocarbon based on one carbon atom sharing an electron with four hydrogen atoms. Hence, methane’s molecular formula is CH4. On the other hand, gasoline is formed by long chains of carbon-hydrogen bonds designated as C11H24 or C12H26. An example of some hydrocarbons is shown below:
Why do hydrocarbons make an excellent fuel source? There are a multitude of reasons. Hydrocarbons produce a lot of energy and can be controlled during combustion. Economically, fossil fuels are easy to store and transport. That also makes gasoline difficult to replace as not only do new automobile engines need to be designed, but a new infrastructure would need to be built to replace the current refinery-pipeline-gas station system. While great strides are being made in alternative fuel sources, fossil fuels will be a significant player in the economy for the foreseeable future.
To see why this is a concern, we’ll take a look at a simplified version of the carbon cycle below.
Note how the use of fossil fuels results in a net intake of 6 billion (Gt=giga tons, giga = 1 billion) tons of carbon into the atmosphere. Carbon is recycled between the land, oceans, and atmosphere. Why do fossil fuels emit more carbon into the atmosphere than absorbed back into land? The reason is, it takes millions of years to form fossil fuels but only a few months to extract and burn it. It’s the same if you run more water into a bathtub than the drain can take away. So, what happens to that carbon when fossil fuels are burned and released into the atmosphere?
Carbon Dioxide
To understand how carbon dioxide is formed, lets take a look at an oxygen atom below:
Note that oxygen has 6 electrons in the outer shell that can hold eight electrons. Remember, the carbon atom has 4 empty spots in its outer shell to share. That being the case, two oxygen atoms will combine with a single carbon atom so that the outer shells of the oxygen atoms will be completely filled with eight electrons and are “happy”.
Methane is the simplest of the hydrocarbon fuels. What happens when methane is burned for energy?
Oxygen is used as a catalyst to burn methane as follows:
CH4 (methane) + 2O2 -> CO2 (carbon dioxide) + 2H2O + energy
Note that each side of the equation contains 1 carbon atom, 4 hydrogen atoms, and 4 oxygen atoms. When fossil fuels are burned for energy, carbon dioxide is released in the exhaust and into the atmosphere.
Greenhouse Gases
The composition of the Earth’s atmosphere is as follows:
Nitrogen: 78%
Oxygen: 21%
Argon: 0.9%
Carbon Dioxide: 0.03%
Methane: 0.00017%
How is it that trace gases such as carbon dioxide and methane play a dominant role in the greenhouse effect but nitrogen and oxygen do not? That is a matter of the molecular structure of each substance. Before we get into that, lets take a look at the role greenhouse gases have on Earth’s ability to support life.
To appreciate greenhouse gases on Earth, we’ll take a look at a place without greenhouse gases, the Moon. The Moon is the same distance from the Sun as the Earth and provides a baseline to examine. Below is a comparison of average temperature on the Moon and on Earth:
Moon: 00 F
Earth: 600 F
In other words, without greenhouse gases, the average temperature of the Earth would be the same as the Moon at 00 F. At that temperature, water on Earth would be frozen and human life would not exist. The point here is that greenhouse gases are not “bad”. In fact, we need those gases to survive. However, too much of a good thing can be a bad thing and that includes greenhouse gases.
What makes a gas a greenhouse gas?
That question can be answered by looking at the molecular structure of the gases that exist in the Earth’s atmosphere. Some molecules, such as carbon dioxide, have molecular bonds that can stretch and vibrate, while others, such as nitrogen and oxygen, have molecular bonds that are rigid. In addition, the molecules whose bonds can vibrate are choosy at which frequencies they vibrate. To understand this better, take a look at the electromagnetic (EM) spectrum below:
Note that radio, microwaves, infrared, light, ultraviolet, x-rays, and gamma rays are all forms of EM radiation. What differentiates the various types of EM radiation are the wavelengths. The shorter the wavelength, the more energy the EM radiation has. That is why gamma rays are very damaging to life and we must be careful not to overexpose ourselves to x-rays and ultraviolet rays. Greenhouse gases only absorb radiation in the infrared range. What exactly is infrared radiation?
As you can tell from the image above, our eyes can only detect a small part of the EM spectrum. Infrared radiation is one form that we cannot see but can feel as heat. The vibrational motions of atoms and molecules produce infrared radiation and all objects radiate in the infrared. In fact, humans radiate most strongly in the infrared as does the planets, including Earth. Night vision goggles are basically infrared sensors. Detecting heat from objects at night allow us to see those objects in the dark. Below is an image of a cat in infrared:
Note the yellow areas on the infrared image. These are the warmest areas of the cat. The nose, which is dark, is the coolest area of the cat.
As sunlight strikes the Earth’s surface, the ground warms and radiates the energy back into the atmosphere as heat or infrared radiation.
What happens when infrared radiation encounters a greenhouse gas? The gas molecule absorbs the infrared energy and converts it to kinetic energy via vibration of molecular bonds. The molecule then stops vibrating and reconverts the kinetic energy back into the atmosphere as infrared energy where surrounding carbon dioxide molecules repeat the process. This prevents the infrared radiation from entering the upper atmosphere and escaping into space. In essence, increasing greenhouse gases is like throwing an extra blanket on the Earth.*
The impact of the greenhouse effect is twofold. One, it traps heat in the lower atmosphere. This increases global temperature near the surface. Second, by preventing heat from escaping into the upper atmosphere, it cools the stratosphere. This provides us with a key diagnostic tool to test if greenhouse gases are causing increasing surface temperature. If the increase in surface temperature originates from another forcing such as solar irradiance, then both the lower and upper atmosphere would become warmer. So how does the evidence look? The answer is below:
As the lower atmosphere has warmed the upper atmosphere has cooled. A good portion of the upper atmospheric cooling is due to ozone loss. The less ozone there is, the less ultraviolet radiation is absorbed in the stratosphere. However, the loss of ozone has not been enough to explain all the stratospheric cooling. The rest is caused by the greenhouse effect. You’ll note the two short-term spikes in stratospheric temperatures around 1983 and 1992. These were generated by volcanic ash ejected into the upper atmosphere from two separate explosions. The aerosols reflect sunlight and heat the stratosphere. However, the effect lasts on the order of 2-3 years and should not be confused with long-term trends.
Carbon Isotopes
All carbon atoms come with six electrons and six protons. Where they differ is in the amount of neutrons in the nucleus. Most carbon atoms have six neutrons, about 1% have seven neutrons and one out of a trillion will have eight neutrons. Plant life produces carbon dioxide that favor the common six neutron configuration. As fossil fuels consist of the remnants of past life on Earth, burning it produces less of the heavier seven and eight neutron carbon atoms than natural processes. If the increase in atmospheric carbon dioxide is a result of the burning of fossil fuels, we would expect it to have a higher ratio of lighter six neutron carbon atoms. Indeed, the amount of six neutron carbon to seven neutron atoms has increased since 1850, and are at their highest levels in at least 10,000 years.
Thus, the theoretical model meets data, meaning the best explanation is climate change is caused by human made greenhouse gases, especially carbon dioxide.
*Gavin Schmidt uses this analogy in his book Climate Change. As Schmidt notes, like most analogies this is not perfect. Under a blanket, heat is generated by the person using it. In the atmosphere, the energy is received above from the Sun in the form of light and transformed and radiated by the ground in the form of infrared radiation.
**Image atop post is NASA computer model on the global distribution of carbon dioxide. Credit: NASA’s Goddard Space Flight Center/B. Putman
“And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind.” – Revelation 6:13
On the night of November 13, 1833, a young Illinois man was awakened by an urgent rap on the door. A Presbyterian Deacon was issuing warnings to his neighbors that the day of judgement had arrived. The young man walked outside to see hundreds of falling stars in the sky. Noting that the constellations were in their usual spots, Abraham Lincoln concluded correctly that this was an unusually intense meteor storm and not the end of the world. This scene was repeated across North America as many resorted to the biblical interpretation of what was happening. When the Sun rose the following morning, a shaken populace realized life would go on as normal. This meteor storm would begin our modern understanding of the science behind these events.
The world of 1833 was one without electric lights and the Moon had set in the early evening giving North America an unobstructed view of one of the great astronomical events in modern times. The Leonids, an annual meteor shower that yields about a dozen meteors per hour, generated tens of thousands of meteors per hour in 1833. Prior to this event, meteors were thought to be an atmospheric phenomena. The word meteor is derived from Greek as meaning high in the sky and of course, is also the basis for the word meteorology. Some good old fashion detective work by Denison Olmsted kick-started the modern science of meteors.
Olmsted examined depictions of the meteor storm from across the nation via newspaper accounts, an arduous task 165 years before Google arrived on the scene. His report included descriptions from New Haven, Boston, West Point, Maryland, Ohio, South Carolina, Georgia, and Missouri. Olmsted also received word of a similar event in 1799, a finding that would play a key role in his investigation. A cold front had moved through the eastern half of the United States dropping temperatures 15 to 30 degrees. This had the effect of clearing haze from the previous days unusually warm weather making the seeing even more ideal.
Olmsted had noted there were no unusual observations from magnetic instruments. This is important as some reports came in that the storm was accompanied by aurora. Finally, Olmsted discovered that the meteors had radiated from a point in the constellation Leo.
This data had led Olmsted to deduce that meteors were not an atmospheric event but caused by a cloud of debris in space. This theory was strengthened in subsequent years as observations confirmed the meteor shower was an annual event – albeit with much less intensity than the 1833 storm. The question remained, where did this debris come from and why was the 1833 storm so unique in its magnitude? It would take another three decades to obtain the answer.
In 1866, Comet Tempel-Tuttle was discovered as it approached the Sun. It had been observed before, but it was on this pass where its 33 year orbit was calculated to intersect the Earth’s orbit. As a comet approaches the Sun, it forms two tails. Radiation pressure from sunlight creates a dust tail, and ultraviolet radiation ionizes gas from the comet which is then swept away by the solar wind. Cometary tails are very tenuous. In fact, you could fit the contents of the tail inside a suitcase. However, when these small particles strike the Earth’s atmosphere at high speeds, they burn up and cause the streaking meteors we see on the ground. In the case of Comet Tempel-Tuttle, it leaves a fresh deposit of debris every 33 years. This will often, as in the case of the 1833 pass, result in a spectacular meteor storm.
All annual meteor showers are produced this way and the interactive below demonstrates how Comet Tempel-Tuttle generates the annual Leonids meteor shower.
Can a meteor storm generate an aurora as some reported in 1833? The answer is no. Comet debris are insufficient in mass to disturb the Earth’s magnetic field to create an aurora in the mid-latitudes. It is possible the quantity of meteors created an optical illusion of background light mistaken fo an aurora.
In 1866, observers in Europe measured hundreds of meteors per hour confirming the comets role in producing the storm. Some detective work was required to link Comet Tempel-Tuttle’s prior passes to other meteor storms. It was discovered that Chinese astronomers observed a Leonid storm in 902 AD. In 1630, two days after Johannes Kepler passed away, another Leonid storm was seen. And in 1799, as noted by Dennison Olmsted’s research, an intense storm occurred. A large storm such as these do not happen with each pass. The years 1899 and 1932 produced upticks in meteor counts, but were disappointments for those hoping for a repeat of the 1833 storm. However, 1966 & 1999 produced bursts of several thousand meteors per minute. Still, the 1833 event stands alone as the greatest of all meteor storms.
The legend of the 1833 Leonids lived for decades afterwards. Frederick Douglass recounted his memory of the meteor storm in his 1881 autobiography.
“…was also the year of that strange phenomenon when the heavens seemed about to part with their starry train. I witnessed this gorgeous spectacle, and was awe-struck. The air seemed filled with bright descending messengers from the sky. It was about daybreak when I saw this sublime scene..” – Life and Times of Frederick Douglass by Frederick Douglass , page 127.
“Probably no celestial phenomenon has ever occurred in this country, since its first settlement, which was viewed with so much admiration and delight by one class of spectators, or with so much astonishment and fear by another class.”
By the end of the 19th Century, the nature of meteor showers was understood not to be a harbinger of the end of the world. America had experienced much history between 1833 and 1900. Frederick Douglass was five years away from freedom when he witnessed the 1833 meteor storm. Lincoln was 30 years away from presiding over the most costly war in American history. By the end of the century, America was an emerging power that over the ensuing five decades and two world wars, would take over global leadership formally held by the European colonial powers. Leaving fear and superstition behind in favor of knowledge and education played no small role in that transformation.
*Image atop post is a woodcut carving of 1833 Leonid meteor shower over Niagara Falls. One witness described as such: “No spectacle so terribly grand and sublime was ever before beheld by man as that of the firmament descending in firery torrents over the dark and roaring cataract.” – From the Bible Readings for the Home Circle, page 367.
As Apollo 11 sat on the launch pad, ready to complete what is arguably the most impressive technical achievement in history, a group of protesters marched towards Cape Kennedy. Had he not been assassinated a year earlier, Martin Luther King Jr. would have led the march. In his place was his best friend, Ralph Abernathy, who took over King’s role as head of the Southern Christian Leadership Conference. As Abernathy put it, the protest was not against the Apollo program per se, but to “protest America’s inability to choose human priorities.” As we live in a democracy, proponents of space exploration should be prepared to answer the question, how does the space program benefit the poor and the general public?
These thoughts came back to me while watching I Am Not Your Negro, the documentary on James Baldwin. There is a tendency to think of the 1950’s and 60’s as when America was great. Certainly, the economy was booming and middle class wages were rising, but as the documentary detailed, America was suffering from terrible social strife. Progress was made legislatively on civil rights, but there were race riots in the cities claiming scores of lives along with a general spike in violent crime. It was against this backdrop that the Apollo program existed.
There is the standard argument that the funds spent on the space program are minuscule compared to the overall federal budget. And that is true, NASA’s spending is about 0.5% of the budget and peaked during the Apollo era at 5%. Current spending on NASA comes out to $60 per person per year. So is NASA just a highly publicized target for protest? I think we have to look at the problem in a different light. That being a policy of resource/education deprivation certain portions of the American population have endured in our history.
Resource deprivation is a hallmark of authoritarian regimes. If people are struggling to survive on a day-to-day basis, it makes it more difficult to sustain political resistance. The history of African-Americans is certainly one of life under authoritarianism, from slavery to Jim Crow era lynchings and segregation. And while significant improvements on that front have been made the past few decades, African-Americans continue to experience the impact of historical resource deprivation in terms of household wealth.
A key historical component of segregation was job discrimination. During its early years, NASA ranked at the bottom of all federal agencies when it came to minority hiring. While the book and subsequent movie, aptly named Hidden Figures, reveals crucial contributions to the Apollo program by African-Americans, the public face of NASA, the astronauts and mission control, were all white. It was this facade that led Gil Scott-Heron to record Whitey on the Moon.
So where do we go with this? NASA has improved the diversity of its workforce greatly. Kennedy Space Center employees are currently 27% minority. While that helps those employed by NASA, what about Americans who live in poverty? If one is segregated from the space program, you have no reason to support it, but that is true of any endeavor. It’s no different than building a shopping mall without access to public transit, or a museum, or schools that are inaccessible to minorities. The key to long-term sustainability is to integrate the benefits of the space program to all corners of society.
The Apollo program lacked this sustainability. Once the political aim of beating the Soviet Union to the Moon was achieved, the Apollo program was cancelled during the recession of the early 1970’s. Lost was the science phase of the program – Apollo missions 18-20. In fact, support for the Apollo program among the American public was tepid. The only time more than half the public approved expenditures on Apollo was briefly in 1969 during the first Moon landing. And even then, approval was only 53 percent. The key to changing this is to turn space exploration from a “spectator sport” to one the public can actively participate in.
One obvious way of achieving this is integrating NASA research in K-12 education. The amounts of data pouring in from NASA missions often require the efforts of citizen science to sort through it all. Such an effort also requires educator training since many teachers, especially in high-need districts, teach outside their specialty. And this effort should seek to aggressively reach out to the districts highest in need. If successful, a public actively engaged in space exploration will tend to be more supportive of it. Is exploring space worth this time and effort?
Perhaps the most important aspect of space exploration is understanding how the Earth fits in the universe. Right now, there are no other planets where humanity can commence a mass migration. Colonizing Mars, while feasible, is much more difficult than living in Antarctica, where only a few dozen scientists live at any given time. We may discover Earth-like planets around other stars, but traveling to them as seen in Star Trek or Star Wars will not occur in our lifetimes, if at all. Understanding this, and the fragile protections Earth offers humanity from a universe largely hostile to life, underscores the urgency in solving key environmental issues such as climate change.
Astronomy is among the most ubiquitous of the sciences. Across all the continents and spanning throughout history, civilizations have sought out answers to what lies in the sky above them. Nations that have been economically and socially healthy have been ones who have made the greatest advancements in astronomy. Recently, the Trump administration has floated ambitious plans to return to the Moon by 2020. By nature, space enthusiasts have jumped on the bandwagon. However, as history has shown, if the United States also embarks on a program of resource deprivation such as repealing ACA, cutting Medicare, and turning education over to for-profit interests, public support for space exploration spending will not only be weak, but hostile. The protest led by Ralph Abernathy in 1968 will look like a Sunday picnic by comparison.
During the Apollo program, it was often suggested that the management methods of the space program could be transferred towards solving poverty. The space program cannot solve poverty, nor should it claim to be capable of that. However, the space program can play a partnership role with the rest of the government and private entities toward that goal. If we really want a sustained effort to go to the Moon, Mars, and beyond, it will have to be within an overall framework of a civilization that values inclusiveness and equality. As Ralph Abernathy stated after watching the launch of Apollo 11:
“This is really holy ground. And it will be more holy once we feed the hungry, care for the sick, and provide for those who do not have houses.”
*Image atop post is Apollo 11 on the launchpad during the early morning hours of July 16, 1969. Credit: NASA.
This September, one of NASA’s greatest success stories will come to an end. After 13 years orbiting Saturn and sending a probe to make the most distant landing in history, the Cassini mission will end with a controlled descent into Saturn. Thirty-five years in the making, Cassini was hatched during one of the darkest hours in NASA’s planetary program. The mission will stand as a centerpiece of a golden era of planetary exploration that has included a Jupiter & Venus orbiter, asteroid missions, and several Mars orbiters and rovers.
In 1981, the Reagan administration proposed shutting down NASA’s planetary program. For awhile, it appeared Voyager 2 would be terminated before its flybys of Uranus and Neptune. The nation was in its worst economic crisis, up to that point, since the Great Depression as unemployment soared past 10%. Scientists expressed deep alarm over planned spending cuts across the board. It was in this environment a joint working group between the National Academy of Sciences and the European Science Foundation proposed the Saturn orbiter/Titan probe mission. The intention was to follow-up the recent Voyagers 1 & 2 flybys of Saturn with a more in-depth research program.
By the mid ’80’s, the economy began to recover, and thanks to aggressive lobbying efforts by NASA, the planetary program (including Voyager 2) survived. In 1989, Congress approved funding for the mission to go ahead. During the early 90’s, on the heels of another economic recession, the Bush and Clinton administrations mandated NASA to cut the cost of the mission. Many of the improvements made on Cassini during this phase were also implemented on NASA’s subsequent “cheaper, faster, better” planetary missions. Finally, in 1997, Cassini-Huygens was ready to launch and begin its seven-year journey to Saturn.
NASA named the orbiter after Giovanni Domenico Cassini, an Italian astronomer who became director of the Paris Observatory in 1671. Among his many discoveries was the division of Saturn’s rings. The gap would separate what would be called the A Ring and B Ring. Since then, several gaps have been discovered with major divisions designated as rings C through G.
The Huygens lander, intended to land on Saturn’s moon Titan, was named after Christiaan Huygens. In 1655, Huygens discovered Titan which earned him the honor over three centuries years later.
Cassini was launched on October 15, 1997. Its trajectory towards Saturn was not a straight shot but looped around the inner Solar System to complete two flybys of Venus, one of Earth, then finally, one of Jupiter in 2000 to put it on course towards Saturn.
The flyby maneuver uses a planet’s gravity to slingshot the probe to the required velocity to reach its target. Not unlike Marty McFly in Back to the Future on his skateboard hitching on to a car to increase his speed. This reduces the amount of fuel needed at launch which reduces weight. In space exploration, weight means cost – about $10,000 a pound to lift payload from Earth.
Cassini finally reached Saturn on June 30, 2004, twenty-two years after the original proposal. On Christmas Day, Huygens departed from Cassini and landed on Titan on January 14, 2005. Titan, the second largest moon in the Solar System, was a mystery as its hazy atmosphere shrouded the surface. Besides Earth, Titan is the only body in the Solar System to have a nitrogen rich atmosphere.
What did we find out about Titan? Methane plays the same role on the surface that water does on Earth. Methane melts at -295.6 F, which is close to the surface temperature recorded by Huygens. Before the landing, astronomers speculated Titan had large methane oceans. In fact, Huygens was designed to float if that was the case. Huygens descended on land, but the orbiting Cassini has detected methane lakes near the poles.
While there is not an ocean on the surface of Titan, Huygens was able to detect a vast underground ocean via radio waves some 35 to 50 miles beneath the surface.
And Cassini itself? The discoveries made over the past 13 years are far too many to detail in a blog post, but here are a few of the highlights.
Enceladus
The sixth largest moon of Saturn, its icy surface reflects almost 100% of light making it very bright. In 2005, Cassini discovered icy plumes emanating in the Southern Hemisphere ejecting material thousands of miles into space. Not unlike Old Faithful, but more powerful and a not understood heat source. In 2015, Cassini flew through the plumes and detected, besides water vapor and ice, hydrocarbons such as methane and formaldehyde. Cassini has also verified the presence of an ocean 26 to 31 km (16 to 19 miles) in depth. To compare, the deepest point in the Pacific is 11 km.
The Rings
Cassini has provided an in-depth look at perhaps the most famous feature in astronomy. Among the many firsts was a view of the vertical structure of the rings. In the image below, structures arise from the B ring to cast shadows much as buildings would do on Earth. The structures causing these shadows are about two miles high.
Saturn’s Poles
Cassini gave us a look at the poles that earlier flyby missions could not. When Cassini first arrived at Saturn, it was summer in the Southern Hemisphere so the South Pole was in daylight while the North Pole was dark. What was found at the South Pole was a hurricane type storm two-thirds the size of Earth. The dynamics of this storm are not completely understood as it is locked at the pole and there is no ocean to feed it energy.
By 2009, it was spring in the Northern Hemisphere (A Saturn year equals 29 Earth years) and finally, the North Pole was in daylight. Cassini discovered a hexagonal shaped jet stream formation. Inside the hexagon is a hurricane type storm. Just like the South Pole, this feature is not completely understood.
Now in its 20th year in space, like an old car, Cassini is near the end of its useful life. As its fuel supply gets lower and lower, there is the possibility that Cassini could be lost to ground control. As the mission has discovered environments on Titan and Enceladus that could sustain microbial life, NASA wants to avoid the possibility of a crash on those two moons contaminating them with Earth microbes from Cassini. Cassini will be in a ring-grazing orbital mode in the final phase of its mission until the end. As Cassini is maneuvered closer and closer to the rings, it will give us with a look at the rings its namesake could only dream about. Cassini will crash into Saturn on September 15, 2017.
The total cost of the Cassini mission has been $3.26 Billion or $163 million per year in space. That’s a tad more than the $158 million the Buffalo Bills spent on their player payroll in 2016.
For a project conceived during a time when NASA’s planetary program was in danger of being terminated, Cassini has left a remarkable legacy 35 years in the making and spanning six presidential administrations. Perhaps the most important lesson Cassini provides is no matter how dark times seem, keep pushing for your dream.
*Image atop post taken April 25, 2016 as Saturn’s Northern Hemisphere approaches summer exposing entire polar region to sunlight. Credit: NASA/JPL-Caltech/Space Science Institute.
Feynman begins his tale with the travel arrangements from Ithaca to Buffalo. He was spared the three hour drive by flying Robinson Airlines, with the plane piloted by Mr. Robinson himself. This regional airline was one of the many that began service after the war and would supplant train travel over the next few decades. Robinson Airlines eventually became Mohawk Airlines which was bought out by Allegheny Airlines in 1970. Allegheny changed its name to US Air in 1979 and was folded into American Airlines in 2015. A picture of a Robinson airplane along with Mr. Robinson can be found here.
Cornell gave Feynmen a $35 ($350 in 2017) stipend each week for his trouble. At first, Feynmen considered saving the money, but Feynman being Feynman, decided to use the funds to look for some adventures while in Buffalo after his lectures at the Cornell Aeronautical Laboratory. The facility was originally operated by Curtiss-Wright, but as the war ended, the company downsized its production in Buffalo greatly and turned the lab over as a gift to Cornell. During its run as a Cornell facility, the staff invented the crash test dummy, seat belts, and developed aircraft simulators. Now privately operated, the facility is still located across the street from the airport and is known as Calspan.
Feynman was hired by Cornell after working at the Manhattan Project where he became known for his uncanny ability to quickly solve equations and for picking locks. The latter was Feynman’s way of irking the powers that be at the project. During the first atomic test at the Trinity site, Feynman threw off his eye protection gear so as to be one of the few to actually witness the blast. However, Feynman eventually became melancholy over both the destructive nature of the atomic bomb and the death of his wife in June 1945 from tuberculosis. This may have contributed to his slow career start at Cornell.
“I would see people building a bridge and I would say “they don’t understand.” I really believed that it was senseless to make anything because it would all be destroyed very soon anyway, but they didn’t understand that and I had this very strange view of any construction that I would see, I would always think how foolish they are to try to make something. So I was really in a kind of depressive condition.” – Richard Feynman from the documentary The Pleasure of Finding Things Out.
Nonetheless, when Feynman got to Buffalo, he asked a local cab driver, a man named Marcuso, driving cab No. 169, to take him to a bar “with lots of interesting things going on.” The cabbie drove Feynman to the Alibi Room located at 8 W. Chippewa near the corner of Main St. The late 40’s, at the start of the post-war boom but before the exodus to the suburbs starting in the ’50’s, was when downtown was in its peak. The Alibi Room was situated in the heart of the theater district and the scene would have looked like this as Feynman’s cab approached the bar.
The Alibi Room itself was new, first appearing in the Buffalo Register in 1946. Feynman described it as a place where, “The women were dressed in furs, everybody was friendly, and the phones were ringing all the time.” As Feynman would later find out, the phones were ringing all the time as it was a local bookie joint, and the women in furs were ladies of the night. This is confirmed by my discussions with those familiar with the Alibi Room. Eventually, Feynman settled into a routine where he would order shots of Black and White scotch with chaser of water and close the place down at 2 AM – Buffalo’s current 4 AM closing time did not go into effect until the 1970’s.
This went on for the duration of the semester. Sometimes, Feynman would end up at an after hours speakeasy. Following his last lecture of the semester, Feynman found himself in a fight in the restroom at the Alibi Room. Once the situation calmed down, Feynman downed a shot of scotch, started talking loud, almost caused hostilities to resume at the bar with three friends of the original antagonist. Another regular at the bar, whom an appreciative Feynman later described as a first-rate expert in diffusing bar fights, interceded by pretending to be a friend of Feynman, then convinced Feynman to leave. Returning to Cornell with a black eye, Feynman went to teach his class, looked at his students, shiner and all, toughened up his tone of voice and asked…
“Any Questions?”
That was the end of Feynman’s adventures with Buffalo nightlife. In 1951, Feynman moved on to Caltech where he developed a quantum theory of electromagnetism. Referred to as quantum electrodynamics (QED), this theory incorporated relativity with quantum mechanics. Merging the two fields is the holy grail of physics. There are four basic forces of nature, electromagnetism, weak nuclear (released in radioactive decay), strong nuclear (released in nuclear explosions), and gravity. The first three are explained by quantum mechanics, the physics of atomic scale. Gravity is explained by relativity, the physics of large scale that we can see. Finding a quantum theory of gravity would unify relativity and quantum mechanics into “the theory of everything.”
Interestingly enough, despite unifying electromagnetism into quantum mechanics, Feynman was ambivalent about finding the theory of everything…
“Are you looking for the ultimate laws of physics? No, I’m not, I’m just looking to find out more about the world and if it turns out there is a simple ultimate law which explains everything, so be it, that would be very nice to discover. If it turns out it’s like an onion with millions of layers and we’re just sick and tired of looking at the layers, then that’s the way it is, but whatever way it comes out its nature is there and she’s going to come out the way she is, and therefore when we go to investigate it we shouldn’t pre-decide what it is we’re trying to do except to try to find out more about it.” – Richard Feynman from The Pleasure of Finding Things Out.
A decade later, around the time he was awarded the Nobel Prize, Feynman found himself in Buffalo once again and paid the Alibi Room a visit. His former adversaries were nowhere to be found. What would have happened if he had bumped into them again? Knowing Buffalo, and that generation, they probably would have bought Feynman a beer (or a Black and White) and had a good laugh.
This time around Feynman found the scene different, describing the formally posh bar and neighborhood as seedy. During the 1950’s, in Buffalo and across America, the middle-class fled the cities for the ranch houses and shopping malls in suburbia. The downtown stores started to close and buildings became vacant. Chippewa St. was on its way to becoming a red light district populated with flop houses, topless bars, and adult book stores. The street reached its nadir in the 1970’s.
Oddly enough, there was an optical lab located on Chippewa during the ’70’s. How do I know this? Before the age of one hour glasses, a repair job for broken glasses could take a week or more. After breaking my glasses in 6th grade, my eye doctor suggested I take them directly to the lab on Chippewa for a quick repair. I hopped on the No. 24 bus, got off at the foot of Chippewa, and headed for the Root Building where the lab was located. This was intriguing as Chippewa was the focal point for much of our middle school humor, but my trip was uneventful. I walked by the Alibi Room without taking note, unaware a Noble Prize physicist once hung out there. Got my glasses back, walked back past the forlorn Chippewa storefronts, noting how much the street resembled the ones television detective Baretta worked.
By the late ’70’s, the Alibi Room changed owners and was now operated as the New Alibi Lounge. I was not able to find any images of the original Alibi Room, given the going ons inside, I imagine photography would have been frowned upon. One image does survive from 1980 which shows the overall decline of the area Feynman commented on.
Within a few years, all the buildings, including the former Alibi Room, would be gone. Cleared out in an urban renewal project, this block was an empty lot for most of the ’80’s when Feynman wrote Surely Your Joking, Mr. Feynman! The book was a best seller and Feynman became even more well known to the public as a member of the commission to investigate the Challenger disaster. It was Feynman who demonstrated to the public how the O-rings in the shuttle’s solid booster would have become brittle during the cold weather conditions the Challenger launched in.
Feynman passed away in 1988. At the same time, Fountain Plaza was rising on the former site of the Alibi Room. Once home to local banking operations, Fountain Plaza is now the site of IBM’s Buffalo Innovation Center as part of the continuing transition of the local economy.
Throughout the 1990’s, Chippewa and the surrounding Theater District experienced a renaissance. Mark Goldman got the ball rolling with the Calumet Arts Cafe, also played a key role in the development of Canalside. The Root Building is now home to Emerson Commons, part of Emerson High’s Culinary program. Once again, Chippewa is an entertainment center in the city.
Beyond physics, Feynman’s legacy continues in education. During a stint on California’s Curriculum Commission, Feynman was critical of common educational techniques. For example, rather than emphasize memorization, Feynman pushed for comprehension of physical concepts. Feynman also wanted children to understand there are a variety of ways to solve mathematical problems. His reasoning is that scientists focus on getting the right answer, not a rote process. This is the underpinning of common core curriculum.
Common core is part of an overhaul to move education away from being geared toward the old industrial economy to one more suited for the 21st Century. During the early 1900’s, rural residents moved to cities as farming became mechanized, reducing the need for labor. The educational system was geared to train students for life in the manufacturing economy. Now, 100 years later, manufacturing is becoming more robotized, meaning labor has to switch over to a knowledge based economy. Feynman’s insights from his stint evaluating textbooks in the 1960’s influences science education to this day.
Last summer, a friend visited Buffalo and arrived at a downtown hotel. She asked the staff where was a good spot to eat. Like Richard Feynman some 70 years earlier, was suggested to go to Chippewa St. Upon arrival, she witnessed a bar brawl that had extended out onto the sidewalk.
The more things change…
*Image atop post is Richard Feynman giving a lecture on planetary orbits in 1964. Credit: United States Department of Energy/Wiki Commons.
Some 3.2 million years ago, a female hominin lived in the Awash Valley in Ethiopia. Her fossilized skeleton was discovered in 1974 and she was given the name Lucy, after the Beatles song Lucy in the Sky with Diamonds, which had played repeatedly during the expedition. The discovery of Lucy has done much to increase our understanding of the origins of the human race. The new NASA mission, named after Lucy, is anticipated to increase our understanding of the origins of the Solar System. That, along with the Psyche mission, will explore asteroids as part of NASA’s Discovery program.
The Discovery program was initiated in 1992 as part of an effort to provide “faster, better, cheaper” missions. This was in response to funding cuts in the early 90’s as part of an overall effort that eventually balanced the federal budget. These missions typically cost around $400-500 million as opposed to Flagship missions such as Cassini which cost $1.5 billion. Prior Discovery missions have included Mars Pathfinder, the Messenger mission to Mercury, and the Kepler mission that unearthed thousands of exoplanets. The initial Discovery mission was NEAR, which was the first to land on an asteroid. With Lucy and Psyche, the Discovery program is returning to its roots.
In grade school, when we learn about the Solar System, we are typically presented with a model of the planets with the main asteroid belt located between Mars and Jupiter. Lucy will flyby one asteroid in the main belt but then move on to examine six Jupiter Trojan asteroids. These asteroids are in the same orbit as Jupiter but are situated in the L4 and L5 Lagrange points. These are located 60 degrees behind and ahead of Jupiter in its orbit. At these points, the gravitational tug from the Sun and Jupiter are equal and stable. That is, if an asteroid moves away from this point, the resultant gravitational forces will tug it back in. This is why these regions serve as collection points for asteroids.
Jupiter is not the only planet that shares its orbit with Trojan asteroids. Mars and Neptune have been discovered to have these, along with Earth in 2011.
Why study asteroids? These objects are remnants, or if you will, fossils from the formation of the Solar System 4.6 billion years ago. Chunks of asteroids make their way to Earth in the form of meteorites, but these become contaminated by the Earth’s atmosphere which can compromise the data received. Going directly to the source provides a pristine environment to examine the primordial Solar System. Lucy’s complex trajectory will enable visits to both the L4 and L5 asteroid swarms and to various asteroid types.
Lucy will visit C, D, and P type asteroids. These types are broken down as follows:
C type or carbonaceous – as the name suggests, these asteroids are thought to be rich in carbons. About 75% of known asteroids fall into this type. These asteroids reside in the outer main asteroid belt and beyond.
D type – rare in the main belt and mostly found among the Jupiter Trojans, these asteroids are very dark and reddish in color. The red color could indicate the presence of organic material.
P type – located in the outer main asteroid belt and beyond, these are among the darkest objects in the Solar System. Even redder than D types, it is thought P type asteroids are very rich in organic material.
The reddish tint to these asteroids are thought to be caused by an organic material referred to as tholins. This substance is common in the outer Solar System but cannot exist on Earth as oxygen breaks it down. However, when the Earth was formed the atmosphere was mostly carbon dioxide. Oxygen did not come on the scene until plant life developed to produce it via photosynthesis. Tholins could have been present on Earth in its early history and played a role in the formation of life as it breaks down into amino acids in water. Understanding how the Trojans formed could help us understand how organic material was delivered to Earth to bring about life.
The origins of the Trojan asteroids are unclear. They may have formed near where they are now, or they may be Kuiper Belt objects ejected towards Jupiter as it migrated after the formation of the Solar System. It is hoped Lucy can solve this part of the puzzle in the early Solar System’s history. The instrument package on Lucy will record surface composition and geological characteristics. While Lucy will go to the Jupiter Trojans, Psyche, named after its target, will travel to the more familiar asteroid belt.
Psyche is unique in that, rather than consisting of rocky material, appears to be the left over metallic core from a protoplanet. The core was exposed by a series of impacts cracking open the outer layers. The Psyche mission will allow us to take a look at a planetary core that we cannot do here on Earth. The metallic cores of planets are formed by the process of differentiation.
When a planet is being formed, heating processes caused by gravitational compression, impact events, and radioactive decay allows for melting and differentiation between heavier and lighter elements. The heavy iron and nickel sinks to the core while lighter silicates rise to the surface. On Earth, this has led to four distinct inner layers, the inner core, the outer core, the mantle, and crust as seen below.
What we know about the Earth below the crust is through study of seismic waves. The deepest hole drilled into the crust was the 7.5 mile Kola Superdeep Borehole started by the Soviet Union in 1970 and abandoned in 1992. This was not even halfway through the crust. Eventually, as one digs deeper, the temperature rises to the point where drilling equipment is damaged. As we cannot get anywhere close to the mantle yet, much less the core, this is where the Psyche mission comes in.
The Psyche asteroid is thought to be the left over core from a Mars sized protoplanet. It was a Mars size protoplanet that crashed into the Earth shortly after its formation creating the Moon. Psyche is scheduled to launch in 2023, flyby Earth in 2024 and Mars in 2025 for a gravity assist to bump up its velocity to reach the asteroid in 2030. Then, the mission will provided planetary scientists the first look into what Earth’s core might look like if we could venture to the center of the planet.
The Lucy and Psyche missions will hopefully, allow us to learn about the origins of the Solar System, Earth, and thus, humanity.
*Image atop post is artist rendition of Lucy (left) and Psyche (right) missions. Credit: SwRI and SSL/Peter Rubin.
On November 27 1783, two days after the last of the British troops evacuated New York City to conclude the Revolutionary War, the rector of St. Michael’s Church near Leeds postulated the existence of stars so massive light could not escape its gravitational field. The rector, John Michell, was also a scientist and the first to conceptualize what we now call a black hole. Michell was using Newton’s theory of light consisting of corpuscles that had mass and were affected by gravity in the same manner any other body of mass would be. This didn’t quite turn out the case and would take Einstein’s new theory of gravity described by relativity in 1915 to formalize the concept of a black hole.
Before we get into all that, we need to familiarize ourselves with the concept of escape velocity. This is the velocity required to escape the gravity of a body of mass and is defined as follows:
Vescape = √(2GM/r) where:
G is the gravitation constant = 6.67408 × 10-11 m3 kg-1 s-2
What would have to happen for Earth to become a black hole? Earth’s radius would have to be reduced to the point where the escape velocity is equal to the speed of light at 3.0 x 108 m/s or 186,282 miles per second. For this to occur, Earth’s radius has to be reduced to 9 mm or about a third of an inch. For the Sun to become a black hole, its radius would have to be reduced to 3 km or 1.9 miles. As you probably now have surmised, black holes have to be very dense and/or very small. This is where Einstein comes in.
By the time the 20th Century rolled around, it was thought that light consisted only of electromagnetic waves. As such, gravity would not affect light and thus, Michell’s idea of a dark star had been forgotten. In 1905, Einstein discovered the photoelectric effect. Light striking a metal ejected electrons from the surface meaning light had to consist of particles as well as waves. In 1915, Einstein’s general relativity theory viewed gravity as a bending of space-time rather than a force between two objects. Light would be affected by gravity as it would travel along the bend on space-time around a body of mass. The next step in formalizing a theory of black holes would come from the Eastern Front in Russia during World War I raging at the time general relativity theory was published.
Karl Schwarzschild was a German astrophysicist who had volunteered for military duty in World War I. While calculating artillery trajectories, Schwarzschild somehow found the time to solve Einstein’s field equation for a gravitational field around a non-rotating object. If a mass was smaller than a certain radius, space-time would curve into itself in a manner that would not allow light to escape. This is in some sense, the Michell solution but using Einstein’s relativity theory to describe gravity instead of Newton’s theory. This radius, now called the Schwarzschild radius, is defined as:
rs = 2GM/c2
c = speed of light
Using the Sun as an example:
rs = 2(6.67408 × 10-11 m3 kg-1 s-2)(1.989 x 1030 kg)/(3.0 x 108 m/s)2
rs = 2944 m or 2.94 km
This is to say any mass the size of the Sun with a radius less than 2.94 km will form a black hole. Any light or matter within the 2.94 km radius will not be able to escape the gravitational field of the black hole. The radius defined by this equation is the event horizon surrounding a black hole. The more mass in a black hole, the larger the event horizon. Once an object or light passes the horizon, it can never get back out. However, outside the radius, the effect of gravity is the same. If the Sun’s radius was reduced to the point of being a black hole, Earth’s orbit would remain the same as the Sun’s mass is the same.
Unlike Michell’s concept, rather than a dark star smaller than this radius, a singularity would form. A singularity is an object of only one dimension and of infinite density and is infinitely small (volume = 0). Admittedly, this is a mathematically abstract concept that is difficult to imagine. Think of a gravity well in the image above that has an infinite depth, the proverbial bottomless pit. Time also stands still in a black hole from the perspective of an outside observer. The nature of a singularity seemed so bizarre that Einstein himself doubted there was a physical process that could create such an object. It would be the father of the atomic bomb, Robert Oppenheimer, who would confirm that theoretically black holes could exist.
As a star the mass of the Sun nears the end of its life, it runs out of hydrogen to fuse into helium atoms. What’s left are helium atoms to fuse into carbon, and this type of nuclear fusion burns hotter. This pushes the outer layers outward to form a red giant, a star so large it will swallow up the Earth. Eventually, the helium runs out and the outward expansion ceases. The red giant sheds its outer layers and what’s left over is a planetary nebula surrounding a shrinking core. The core is shrinking as the inner force of gravity is now greater than the outward force of heat produced by fusion. The remaining core is compressed to a white dwarf the size of Earth. That’s pretty dense, in fact one teaspoon weighs 15 tons, but not quite small enough to be a black hole. The radius of a white dwarf is on the scale of a few thousand kilometers and the Sun, as noted above, would have to collapse to smaller than 3 kilometers to be a black hole.
What keeps a sun-like star from collapsing into a black hole are the nuclear forces that bind atoms together. This force is strong enough to keep atoms intact and prevents a gravitational collapse beyond the white dwarf stage. When a star is 8-20 times the mass of the Sun, it ends its life in a supernova explosion. These stars fuse elements up to iron at which point fusion can no longer occur. The resultant supernova leaves an iron core that becomes a neutron star. Here, the gravitational force is strong enough to compress electrons and protons to form neutrons. The density becomes higher than in a white dwarf, one teaspoon of a neutron star weights about 10 million tons. The gravity here is pretty intense but still not quite enough to form a black hole. More mass is required, and this is where Robert Oppenheimer comes in.
In 1939, Oppenheimer, along with his student, George Volkoff, published a paper demonstrating that a collapsing star, with sufficient mass, could overcome nuclear forces and form a singularity. As World War II was about to commence, Oppenheimer found himself busy with the Manhattan Project and the paper generally went forgotten. At the time, general relativity and singularities were considered fallow ground for experimental research. Black holes were still considered an odd offshoot of relativity theory. The problem is, how to observe an object that by definition, does not emit light. The solution could be found in Michell’s 1783 paper and some 20th Century technological advancements.
Michell noted in his paper that a black hole would have to be detected by observing the impact on the mass around it. By the 1960’s, interest had been revived in the topic, especially by John Wheeler. It was Wheeler, in fact, who popularized the term black hole in 1967 (The Star Trek episode Tomorrow is Yesterday, aired in January 1967, refers to a black star). Just three years prior, the first black hole candidate was detected as an x-ray source dubbed Cygnus X-1. Why would the presence of x-ray emissions possibly be a sign of a black hole? The answer lies in the surrounding accretion disk of matter falling into the black hole.
Matter falling in the surrounding accretion disk can be heated up to several million degrees. At this temperature, matter will begin to emit high energy, short wavelength x-rays. We are not able to observe x-rays from the Earth’s surface as they are absorbed in the upper atmosphere. That’s a good thing as x-rays are harmful to life, but it does require observations above the surface. The first observations of Cygnus X-1 in the 1960’s were made by sounding rockets and high-altitude aircraft. The launch of the Chandra X-Ray Observatory in 1999 gave astronomers an opportunity to take a good look at Cygnus X-1 from space.
The hot gas is siphoned off from an orbiting blue giant that is visible. This star orbits Cygnus X-1 every 5.6 days and from that, it can be deduced that Cygnus X-1 is 15 solar masses. There is nothing known that can be that large and not be visible besides a black hole. In 1975, Stephen Hawking bet Kip Thorne that Cygnus X-1 was not a black hole. Since then, Hawking has conceded that he lost the gamble. The age of orbiting telescopes would also reveal a different kind of black hole, one much larger in mass than the remnants of supernova explosions.
M87 is a very large elliptical galaxy containing several trillion stars and is 54 million light years from Earth. Back in the 1950’s, there were hints of something unusual in M87 when a large radio source was detected. When charged particles are accelerated, they emit radio waves. This is the principle behind radio towers as electrons are accelerated up and down the tower producing a radio broadcast. Sounding rockets during the 1960’s detected x-ray sources from the galaxy as with Cygnus X-1. In 1998, the Hubble Space Telescope imaged a jet of electrons and sub-atomic particles protruding from M87. Originally discovered in 1919 at the Lick Observatory, Hubble’s high resolution capabilities determined this 5,000 light year jet was caused by a black hole with a mass 2 billion times that of the Sun.
How does a jet of matter become ejected from a region with a black hole? Astronomers are not quite sure but it appears so much mass is trying to enter the black hole that it results in a traffic jam of sorts. Think of it as shooting a fire hose into a bathtub drain. The rejected material gets shot out along the intense magnetic field surrounding the black hole as charged particles will travel along the path of magnetic field lines. M87 is not the only galaxy with a central black hole, in fact, most galaxies have been discovered to have these including the Milky Way.
During the summer months, the constellation Sagittarius is visible. Located in this constellation is the center of the Milky Way. We cannot see the center as it is shrouded by dust. However, infrared observations allow us to peer behind the dust. The UCLA Galactic Center Group has been using the 10-m Keck Telescope to observe the galactic center since 1995 to track the motions of stars in the region. Just like using the orbit of the blue giant around Cygnus X-1 to determine the properties of the black hole, the UCLA team has been able to determine that the Milky Way’s central black hole is 4 million times the mass of the Sun and has a Schwarzschild radius 17 times the Sun’s radius. Below are the observations from the UCLA team.
What does the future hold for black hole research? One intriguing prospect is the possible existence and detection of atomic sized black holes. Speculation is these would have formed during the Big Bang and pass routinely through our bodies. The CERN supercollider may be able to produce such black holes. No need to worry, it would not present a danger to Earth. Most importantly, black holes represent where quantum mechanics and general relativity theory intersect. Quantum mechanics provides the physics for atomic sized particles, relativity provides the physics for gravity and large objects. Relativity breaks down once you reach the singularity. As the universe was a singularity at the beginning of time, understanding the physics of gravity at this scale is required to understand the universe when it originated. Black holes, once considered an abstract oddity of relativity theory, may be able to provide the key to the answer of how the universe came to exist.
* Image atop post is a computer simulation of a galactic black hole. The edge of the black region is the Schwarzschild radius. The light from stars passing near, but not inside, the Schwarzschild radius is smeared by the curvature in space-time caused by the black hole. Credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)