Daily Archives: November 17, 2021

Quantum mechanics explains how the universe works at a scale smaller than atoms. It is also called quantum physics or quantum theory. Mechanics is the part of physics that explains how things move and quantum is the Latin word for 'how much'. A quantum of energy is the least amount possible (or the least extra amount), and quantum mechanics describes how that energy moves or interacts.

Atoms used to be considered the smallest building blocks of matter, but modern science has shown that there are even smaller particles, like protons, neutrons and electrons. Quantum mechanics describes how the particles that make up atoms work.

Quantum mechanics also tells us how electromagnetic waves (like light) work. Waveparticle duality means that particles behave like waves and waves behave like particles. (They are not two kinds of thing, they are something like both: this is their duality.) Much of modern physics and chemistry can be described and understood using the mathematical rules of quantum mechanics.

The mathematics used to study subatomic particles and electromagnetic waves is very complex because they act in very strange ways.

Photons are particles that are point-sized, tinier than atoms. Photons are like "packets" or packages of energy. Light sources such as candles or lasers produce light in bits called photons.

The more photons a lamp produces, the brighter the light. Light is a form of energy that behaves like the waves in water or radio waves. The distance between the top of one wave and the top of the next wave is called a 'wavelength'. Each photon carries a certain amount, or 'quantum', of energy depending on its wavelength.

A light's color depends on its wavelength. The color violet (the bottom or innermost color of the rainbow) has a wavelength of about 400nm ("nanometers") which is 0.00004 centimeters or 0.000016 inches. Photons with wavelengths of 10-400nm are called ultraviolet (or UV) light. Such light cannot be seen by the human eye. On the other end of the spectrum, red light is about 700nm. Infrared light is about 700nm to 300,000nm. Human eyes are not sensitive to infrared light either.

Wavelengths are not always so small. Radio waves have longer wavelengths. The wavelengths for an FM radio can be several meters in length (for example, stations transmitting on 99.5 FM are emitting radio energy with a wavelength of about 3 meters, which is about 10 feet). Each photon has a certain amount of energy related to its wavelength. The shorter the wavelength of a photon, the greater its energy. For example, an ultraviolet photon has more energy than an infrared photon.

Wavelength and frequency (the number of times the wave crests per second) are inversely proportional, which means a longer wavelength will have a lower frequency, and vice versa. If the color of the light is infrared (lower in frequency than red light), each photon can heat up what it hits. So, if a strong infrared lamp (a heat lamp) is pointed at a person, that person will feel warm, or even hot, because of the energy stored in the many photons. The surface of the infrared lamp may even get hot enough to burn someone who may touch it.Humans cannot see infrared light, but we can feel the radiation in the form of heat. For example, a person walking by a brick building that has been heated by the sun will feel heat from the building without having to touch it.

The mathematical equations of quantum mechanics are abstract, which means it is impossible to know the exact physical properties of a particle (like its position or momentum) for sure. Instead, a mathematical function called the wavefunction provides information about the probability with which a particle has a given property. For example, the wavefunction can tell you what the probability is that a particle can be found in a certain location, but it can't tell you where it is for sure. Because of this uncertainty and other factors, you cannot use classical mechanics (the physics that describe how large objects move) to predict the motion of quantum particles.

Ultraviolet light is higher in frequency than violet light, such that it is not even in the visible light range. Each photon in the ultraviolet range has a lot of energy, enough to hurt skin cells and cause a sunburn. In fact, most forms of sunburn are not caused by heat; they are caused by the high energy of the sun's UV rays damaging your skin cells. Even higher frequencies of light (or electromagnetic radiation) can penetrate deeper into the body and cause even more damage. X-rays have so much energy that they can go deep into the human body and kill cells. Humans cannot see or feel ultraviolet light or x-rays. They may only know they have been under such high frequency light when they get a radiation burn. Areas where it is important to kill germs often use ultraviolet lamps to destroy bacteria, fungi, etc. X-rays are sometimes used to kill cancer cells.

Quantum mechanics started when it was discovered that if a particle has a certain frequency, it must also have a certain amount of energy. Energy is proportional to frequency (Ef). The higher the frequency, the more energy a photon has, and the more damage it can do. Quantum mechanics later grew to explain the internal structure of atoms. Quantum mechanics also explains the way that a photon can interfere with itself, and many other things never imagined in classical physics.

Max Planck discovered the relationship between frequency and energy. Nobody before had ever guessed that frequency is directly proportional to energy (this means that as one of them doubles, the other does, too). Under what are called natural units, then the number representing the frequency of a photon would also represent its energy. The equation would then be:

meaning energy equals frequency.

But the way physics grew, there was no natural connection between the units that were used to measure energy and the units commonly used to measure time (and therefore frequency). So the formula that Planck worked out to make the numbers all come out right was:

or, energy equals h times frequency. This h is a number called Planck's constant after its discoverer.

Quantum mechanics is based on the knowledge that a photon of a certain frequency means a photon of a certain amount of energy. Besides that relationship, a specific kind of atom can only give off certain frequencies of radiation, so it can also only give off photons that have certain amounts of energy.

Isaac Newton thought that light was made of very small things that we would now call particles (he referred to them as "Corpuscles"). Christiaan Huygens thought that light was made of waves. Scientists thought that a thing cannot be a particle and a wave at the same time.

Scientists did experiments to find out whether light was made of particles or waves. They found out that both ideas were right light was somehow both waves and particles. The Double-slit experiment performed by Thomas Young showed that light must act like a wave. The Photoelectric effect discovered by Albert Einstein proved that light had to act like particles that carried specific amounts of energy, and that the energies were linked to their frequencies. This experimental result is called the "wave-particle duality" in quantum mechanics. Later, physicists found out that everything behaves both like a wave and like a particle, not just light. However, this effect is much smaller in large objects.

Here are some of the people who discovered the basic parts of quantum mechanics: Max Planck, Albert Einstein, Satyendra Nath Bose, Niels Bohr, Louis de Broglie, Max Born, Paul Dirac, Werner Heisenberg, Wolfgang Pauli, Erwin Schrdinger, John von Neumann, and Richard Feynman. They did their work in the first half of the 20th century.

Quantum mechanics formulae and ideas were made to explain the light that comes from glowing hydrogen. The quantum theory of the atom also had to explain why the electron stays in its orbit, which other ideas were not able to explain. It followed from the older ideas that the electron would have to fall in to the center of the atom because it starts out being kept in orbit by its own energy, but it would quickly lose its energy as it revolves in its orbit. (This is because electrons and other charged particles were known to emit light and lose energy when they changed speed or turned.)

Hydrogen lamps work like neon lights, but neon lights have their own unique group of colors (and frequencies) of light. Scientists learned that they could identify all elements by the light colors they produce. They just could not figure out how the frequencies were determined.

Then, a Swiss mathematician named Johann Balmer figured out an equation that told what (lambda, for wave length) would be:

where B is a number that Balmer determined to be equal to 364.56nm.

This equation only worked for the visible light from a hydrogen lamp. But later, the equation was made more general:

where R is the Rydberg constant, equal to 0.0110nm1, and n must be greater than m.

Putting in different numbers for m and n, it is easy to predict frequencies for many types of light (ultraviolet, visible, and infared). To see how this works, go to Hyperphysics and go down past the middle of the page. (Use H = 1 for hydrogen.)

In 1908, Walter Ritz made the Ritz combination principle that shows how certain gaps between frequencies keep repeating themselves. This turned out to be important to Werner Heisenberg several years later.

In 1905, Albert Einstein used Planck's idea to show that a beam of light is made up of a stream of particles called photons. The energy of each photon depends on its frequency. Einstein's idea is the beginning of the idea in quantum mechanics that all subatomic particles like electrons, protons, neutrons, and others are both waves and particles at the same time. (See picture of atom with the electron as waves at atom.) This led to a theory about subatomic particles and electromagnetic waves called wave-particle duality. This is where particles and waves were neither one nor the other, but had certain properties of both.

In 1913, Niels Bohr came up with the idea that electrons could only take up certain orbits around the nucleus of an atom. Under Bohr's theory, the numbers called m and n in the equation above could represent orbits. Bohr's theory said electrons could begin in some orbit m and end up in some orbit n, or an electron could begin in some orbit n and end up in some orbit m so if a photon hits an electron, its energy will be absorbed, and the electron will move to a higher orbit because of that extra energy. Under Bohr's theory, if an electron falls from a higher orbit to a lower orbit, then it will have to give up energy in the form of a photon. The energy of the photon will equal the energy difference between the two orbits, and the energy of a photon makes it have a certain frequency and color. Bohr's theory provided a good explanation of many aspects of subatomic phenomena, but failed to answer why each of the colors of light produced by glowing hydrogen (and by glowing neon or any other element) has a brightness of its own, and the brightness differences are always the same for each element.

By the time Niels Bohr came out with his theory, most things about the light produced by a hydrogen lamp were known, but scientists still could not explain the brightness of each of the lines produced by glowing hydrogen.

Werner Heisenberg took on the job of explaining the brightness or "intensity" of each line. He could not use any simple rule like the one Balmer had come up with. He had to use the very difficult math of classical physics that figures everything out in terms of things like the mass (weight) of an electron, the charge (static electric strength) of an electron, and other tiny quantities. Classical physics already had answers for the brightness of the bands of color that a hydrogen lamp produces, but the classical theory said that there should be a continuous rainbow, and not four separate color bands. Heisenberg's explanation is:

There is some law that says what frequencies of light glowing hydrogen will produce. It has to predict spaced-out frequencies when the electrons involved are moving between orbits close to the nucleus (center) of the atom, but it also has to predict that the frequencies will get closer and closer together as we look at what the electron does in moving between orbits farther and farther out. It will also predict that the intensity differences between frequencies get closer and closer together as we go out. Where classical physics already gives the right answers by one set of equations the new physics has to give the same answers but by different equations.

Classical physics uses the methods of the French mathematician Fourier to make a math picture of the physical world, and it uses collections of smooth curves that go together to make one smooth curve that gives, in this case, intensities for light of all frequencies from some light. But it is not right because that smooth curve only appears at higher frequencies. At lower frequencies, there are always isolated points and nothing connects the dots. So, to make a map of the real world, Heisenberg had to make a big change. He had to do something to pick out only the numbers that would match what was seen in nature. Sometimes people say he "guessed" these equations, but he was not making blind guesses. He found what he needed. The numbers that he calculated would put dots on a graph, but there would be no line drawn between the dots. And making one "graph" just of dots for every set of calculations would have wasted lots of paper and not have gotten anything done. Heisenberg found a way to efficiently predict the intensities for different frequencies and to organize that information in a helpful way.

Just using the empirical rule given above, the one that Balmer got started and Rydberg improved, we can see how to get one set of numbers that would help Heisenberg get the kind of picture that he wanted:

The rule says that when the electron moves from one orbit to another it either gains or loses energy, depending on whether it is getting farther from the center or nearer to it. So we can put these orbits or energy levels in as headings along the top and the side of a grid. For historical reasons the lowest orbit is called n, and the next orbit out is called n - a, then comes n - b, and so forth. It is confusing that they used negative numbers when the electrons were actually gaining energy, but that is just the way it is.

Since the Rydberg rule gives us frequencies, we can use that rule to put in numbers depending on where the electron goes. If the electron starts at n and ends up at n, then it has not really gone anywhere, so it did not gain energy and it did not lose energy. So the frequency is 0. If the electron starts at n-a and ends up at n, then it has fallen from a higher orbit to a lower orbit. If it does so then it loses energy, and the energy it loses shows up as a photon. The photon has a certain amount of energy, e, and that is related to a certain frequency f by the equation e = h f. So we know that a certain change of orbit is going to produce a certain frequency of light, f. If the electron starts at n and ends up at n - a, that means it has gone from a lower orbit to a higher orbit. That only happens when a photon of a certain frequency and energy comes in from the outside, is absorbed by the electron and gives it its energy, and that is what makes the electron go out to a higher orbit. So, to keep everything making sense, we write that frequency as a negative number. There was a photon with a certain frequency and now it has been taken away.

So we can make a grid like this, where f(ab) means the frequency involved when an electron goes from energy state (orbit) b to energy state a (Again, sequences look backwards, but that is the way they were originally written.):

Grid of f

Heisenberg did not make the grids like this. He just did the math that would let him get the intensities he was looking for. But to do that he had to multiply two amplitudes (how high a wave measures) to work out the intensity. (In classical physics, intensity equals amplitude squared.) He made an odd-looking equation to handle this problem, wrote out the rest of his paper, handed it to his boss, and went on vacation. Dr. Born looked at his funny equation and it seemed a little crazy. He must have wondered, "Why did Heisenberg give me this strange thing? Why does he have to do it this way?" Then he realized that he was looking at a blueprint for something he already knew very well. He was used to calling the grid or table that we could write by doing, for instance, all the math for frequencies, a matrix. And Heisenberg's weird equation was a rule for multiplying two of them together. Max Born was a very, very good mathematician. He knew that since the two matrices (grids) being multiplied represented different things (like position (x,y,z) and momentum (mv), for instance), then when you multiply the first matrix by the second you get one answer and when you multiply the second matrix by the first matrix you get another answer. Even though he did not know about matrix math, Heisenberg already saw this "different answers" problem and it had bothered him. But Dr. Born was such a good mathematician that he saw that the difference between the first matrix multiplication and the second matrix multiplication was always going to involve Planck's constant, h, multiplied by the square root of negative one, i. So within a few days of Heisenberg's discovery they already had the basic math for what Heisenberg liked to call the "indeterminacy principle." By "indeterminate" Heisenberg meant that something like an electron is just not pinned down until it gets pinned down. It is a little like a jellyfish that is always squishing around and cannot be "in one place" unless you kill it. Later, people got in the habit of calling it "Heisenberg's uncertainty principle," which made many people make the mistake of thinking that electrons and things like that are really "somewhere" but we are just uncertain about it in our own minds. That idea is wrong. It is not what Heisenberg was talking about. Having trouble measuring something is a problem, but it is not the problem Heisenberg was talking about.

Heisenberg's idea is very hard to grasp, but we can make it clearer with an example. First, we will start calling these grids "matrices," because we will soon need to talk about matrix multiplication.

Suppose that we start with two kinds of measurements, position (q) and momentum (p). In 1925, Heisenberg wrote an equation like this one:

He did not know it, but this equation gives a blueprint for writing out two matrices (grids) and for multiplying them. The rules for multiplying one matrix by another are a little messy, but here are the two matrices according to the blueprint, and then their product:

Matrix of p

Matrix of q

The matrix for the product of the above two matrices as specified by the relevant equation in Heisenberg's 1925 paper is:

Where:

A=p(nn-a)*q(n-an-b)+p(nn-b)*q(n-bn-b)+p(nn-c)*q(n-cn-b)+.....

B=p(n-an-a)*q(n-an-c)+p(n-an-b)*q(n-bn-c)+p(n-an-c)*q(n-cn-c)+.....

C=p(n-bn-a)*q(n-an-d)+p(n-bn-b)*q(n-bn-d)+p(n-bn-c)*q(n-dn-d)+.....

and so forth.

If the matrices were reversed, the following values would result:

A=q(nn-a)*p(n-an-b)+q(nn-b)*p(n-bn-b)+q(nn-c)*p(n-cn-b)+.....B=q(n-an-a)*p(n-an-c)+q(n-an-b)*p(n-bn-c)+q(n-an-c)*p(n-cn-c)+.....C=q(n-bn-a)*p(n-an-d)+q(n-bn-b)*p(n-bn-d)+q(n-bn-c)*p(n-dn-d)+.....

and so forth.

Note how changing the order of multiplication changes the numbers, step by step, that are actually multiplied.

The work of Werner Heisenberg seemed to break a log jam. Very soon, many different other ways of explaining things came from people such as Louis de Broglie, Max Born, Paul Dirac, Wolfgang Pauli, and Erwin Schrdinger. The work of each of these physicists is its own story. The math used by Heisenberg and earlier people is not very hard to understand, but the equations quickly grew very complicated as physicists looked more deeply into the atomic world.

In the early days of quantum mechanics, Albert Einstein suggested that if it were right then quantum mechanics would mean that there would be "spooky action at a distance." It turned out that quantum mechanics was right, and that what Einstein had used as a reason to reject quantum mechanics actually happened. This kind of "spooky connection" between certain quantum events is now called "quantum entanglement".

When an experiment brings two things (photons, electrons, etc.) together, they must then share a common description in quantum mechanics. When they are later separated, they keep the same quantum mechanical description or "state." In the diagram, one characteristic (e.g., "up" spin) is drawn in red, and its mate (e.g., "down" spin) is drawn in blue. The purple band means that when, e.g., two electrons are put together the pair shares both characteristics. So both electrons could show either up spin or down spin. When they are later separated, one remaining on Earth and one going to some planet of the star Alpha Centauri, they still each have both spins. In other words, each one of them can "decide" to show itself as a spin-up electron or a spin-down electron. But if later on someone measures the other one, it must "decide" to show itself as having the opposite spin.

Einstein argued that over such a great distance it was crazy to think that forcing one electron to show its spin would then somehow make the other electron show an opposite characteristic. He said that the two electrons must have been spin-up or spin-down all along, but that quantum mechanics could not predict which characteristic each electron had. Being unable to predict, only being able to look at one of them with the right experiment, meant that quantum mechanics could not account for something important. Therefore, Einstein said, quantum mechanics had a big hole in it. Quantum mechanics was incomplete.

Later, it turned out that experiments showed that it was Einstein who was wrong.[1]

In 1925, Werner Heisenberg described the Uncertainty principle, which says that the more we know about where a particle is, the less we can know about how fast it is going and in which direction. In other words, the more we know about the speed and direction of something small, the less we can know about its position. Physicists usually talk about the momentum in such discussions instead of talking about speed. Momentum is just the speed of something in a certain direction times its mass.

The reason behind Heisenberg's uncertainty principle says that we can never know both the location and the momentum of a particle. Because light is an abundant particle, it is used for measuring other particles. The only way to measure it is to bounce the light wave off of the particle and record the results. If a high energy, or high frequency, light beam is used, we can tell precisely where it is, but cannot tell how fast it was going. This is because the high energy photon transfers energy to the particle and changes the particle's speed. If we use a low energy photon, we can tell how fast it is going, but not where it is. This is because we are using light with a longer wavelength. The longer wavelength means the particle could be anywhere along the stretch of the wave.

The principle also says that there are many pairs of measurements for which we cannot know both of them about any particle (a very small thing), no matter how hard we try. The more we learn about one of such a pair, the less we can know about the other.

Even Albert Einstein had trouble accepting such a bizarre concept, and in a well-known debate said, "God does not play dice".To this, Danish physicist Niels Bohr famously responded, "Einstein, don't tell God what to do".

Electrons surround every atom's nucleus. Chemical bonds link atoms to form molecules. A chemical bond links two atoms when electrons are shared between those atoms. Thus quantum mechanics is the physics of the chemical bond and of chemistry. Quantum mechanics helps us understand how molecules are made, and what their properties are.[2]

Quantum mechanics can also help us understand big things, such as stars and even the whole universe. Quantum mechanics is a very important part of the theory of how the universe began called the Big Bang.

Everything made of matter is attracted to other matter because of a fundamental force called gravity. Einstein's theory that explains gravity is called the theory of general relativity. A problem in modern physics is that some conclusions of quantum mechanics do not seem to agree with the theory of general relativity.

Quantum mechanics is the part of physics that can explain why all electronic technology works as it does. Thus quantum mechanics explains how computers work, because computers are electronic machines. But the designers of the early computer hardware of around 1950 or 1960 did not need to think about quantum mechanics. The designers of radios and televisions at that time did not think about quantum mechanics either. However, the design of the more powerful integrated circuits and computer memory technologies of recent years does require quantum mechanics.

Quantum mechanics has also made possible technologies such as:

Quantum mechanics is a challenging subject for several reasons:

Quantum mechanics describes nature in a way that is different from how we usually think about science. It tells us how likely to happen some things are, rather than telling us that they certainly will happen.

One example is Young's double-slit experiment. If we shoot single photons (single units of light) from a laser at a sheet of photographic film, we will see a single spot of light on the developed film. If we put a sheet of metal in between, and make two very narrow slits in the sheet, when we fire many photons at the metal sheet, and they have to go through the slits, then we will see something remarkable. All the way across the sheet of developed film we will see a series of bright and dark bands. We can use mathematics to tell exactly where the bright bands will be and how bright the light was that made them, that is, we can tell ahead of time how many photons will fall on each band. But if we slow the process down and see where each photon lands on the screen we can never tell ahead of time where the next one will show up. We can know for sure that it is most likely that a photon will hit the center bright band, and that it gets less and less likely that a photon will show up at bands farther and farther from the center. So we know for sure that the bands will be brightest at the center and get dimmer and dimmer farther away. But we never know for sure which photon will go into which band.

One of the strange conclusions of quantum mechanics theory is the "Schrdinger's cat" effect. Certain properties of a particle, such as their position, speed of motion, direction of motion, and "spin", cannot be talked about until something measures them (a photon bouncing off of an electron would count as a measurement of its position, for example). Before the measurement, the particle is in a "superposition of states," in which its properties have many values at the same time. Schrdinger said that quantum mechanics seemed to say that if something (such as the life or death of a cat) was determined by a quantum event, then its state would be determined by the state that resulted from the quantum event, but only at the time that somebody looked at the state of the quantum event. In the time before the state of the quantum event is looked at, perhaps "the living and dead cat (pardonthe expression) [are] mixed or smeared out in equal parts."[3]

People often use the symbol {displaystyle hbar } , which is called "h-bar." = h 2 {displaystyle hbar ={frac {h}{2pi }}} . H-bar is a unit of angular momentum. When this new unit is used to describe the orbits of electrons in atoms, the angular momentum of any electron in orbit is always a whole number.[4]

The particle in a 1-dimensional well is the most simple example showing that the energy of a particle can only have specific values. The energy is said to be "quantized."The well has zero potential energy inside a range and has infinite potential energy everywhere outside that range. For the 1-dimensional case in the x {displaystyle x} direction, the time-independent Schrdinger equation can be written as:[5]

Using differential equations, we can figure out that {displaystyle psi } can be written as

or as

The walls of the box mean that the wavefunction must have a special form. The wavefunction of the particle must be zero anytime the walls are infinitely tall. At each wall:

Consider x = 0

Now consider: = C sin k x {displaystyle psi =Csin kx;}

We can see that n {displaystyle n} must be an integer. This means that the particle can only have special energy values and cannot have the energy values in between. This is an example of energy "quantization."

See more here:

Quantum mechanics - Simple English Wikipedia, the free ...

Close your eyes, think of the words eccentric genius, and one of the first images is doubtlessly that of Albert Einstein. He is defined by his characteristic hair and aloofness, too smart and preoccupied with space and time to be consumed by the minutiae of daily grooming.

But the idea of genius is often affected by the same social forces that influence what we perceive as alien, illegal or unsophisticated race, gender, class and other statuses that place individuals and cultures on the wrong side of the line between accepted and outsider.

Stephon Alexander is a theoretical cosmologist and professor of physics at Brown University who has learned how to embrace being different while also succeeding in established spaces. His research challenges conventions of gravity, spacetime and the fabric of the universe. Doubling as a jazz musician, Alexander uses his musical perspective to inform the kind of physics that he does. In his 2017 book, The Jazz of Physics: The Secret Link Between Music and the Structure of the Universe, Alexander compared the constraints of physics with music:

Contrary to the logical structure innate in physical law, in our attempts to reveal new vistas in our understanding, we often must embrace an irrational, illogical process, sometimes fraught with mistakes and improvisational thinking.

In his new book, Fear of a Black Universe: An Outsiders Guide to the Future of Physics, Alexander takes it a step further, bringing readers on a whirlwind ride through the nature of reality, modern physics and the true meaning of being an outsider.

Alexander spoke to The Undefeated about his book, what he means by a Black universe and modern questions in theoretical physics.

This interview has been edited for length and clarity.

Can you walk me through the process and motivation behind Fear of a Black Universe?

I first authored the title as a joke. When an agent asked me what I think the book should be called, one day I said, Fear of a Black Universe.

In hindsight, I think it was one of these subconscious things that had to be the title. And then when we start thinking about quantum mechanics, the dualities and concepts like superposition the idea that a concept could have many meanings. And I know in literature there is some device where you can have an ambiguity in the title of things. And so in my book, theres some of this multiplicity, which I felt was perfect given the ways that I look at the universe.

Of course, the title is a homage and reference to Public Enemys Fear of a Black Planet. That album had a tremendous impact on me. You have to remember that I come from an era where I used to wear African medallions and I was listening nonstop to Public Enemy. The album really influenced me, but more than that, the era. People forget that when hip-hop was new, it really was a culture that everyone was afraid of. It was authored by mostly young, Black and Latinx folks in inner cities, and had a raw energy that intimidated people. And so Fear of a Black Planet embodied a lot of these sensibilities, but came right out and said it you all are afraid of us.

But that isnt where my reference to Blackness ends. The experience of being Black is like a rite of passage, you have to go through things and emerge on the other side. You have to dig deep and strive for that excellence in the face of challenges that you might be facing. And the fact that expectations may not exist for you as a Black man or a Black person, a Black scientist.

And then the other key resonance that that title was about the category of Blackness in a broader sense, like in America, that plays itself out as stigma. And as Black people, we have to deal with stigma, and these other things.

Thats a reality that youre constantly feared, a threat to the status quo. And so, part of what I was getting after with Blackness had to do with authoring ideas that are edgy or potentially threatening.

Thats a reality that youre constantly feared, a threat to the status quo. And so, part of what I was getting after with Blackness had to do with authoring ideas that are edgy or potentially threatening. That as a scientist, you can generate ideas in the name of research, in the name of breaking new ground, that may stigmatize you. That may kick you out of the club, so to speak, because youre not necessarily following the herd.

And I dont mean being actively defiant, but becoming stigmatized in the process of trying to make a difference. And the book was also exploring that with other great breakthroughs in physics, people like Michael Faraday and Albert Einstein and Erwin Schrdinger. Ive learned that they had to navigate that space as well.

So in the book, Blackness is a metaphor for the process of embracing that true outsider status that comes with risk-taking, generating Black ideas.

Hence, Fear of a Black Universe. This is a fear, not only of Black people, but of nontraditional personalities and perspectives.

Youre not satisfied with telling another story about a lonely Black person in a white world. You take pride in being original in the science that you describe. What are some modern ideas in physics that excite you?

Part of my mission is to remind people that unusual backgrounds and experiences can really help to foster new ideas in all of these disciplines. And so, while my background may not show up in the minutiae of my theoretical physics, my identity plays a role in how I think, and so is a character in a lot of things.

With regards to new physics ideas that excite me, I think one of them is probably best summarized by a story.

One of my mentors is Leon Cooper, who won the 1972 Nobel Prize in physics for his work on conductivity. For context: Leon solved this problem that was almost 50 years old, that Albert Einstein and Richard Feynman and a lot of greats worked on.

He has always remained close to me. And Ive always been in touch with him throughout my career. Ill often go check in with him when Im at various crossroads.

Years ago, Im talking to Leon in his office at Brown University. He asks me what Im working on. After hearing my answer, he looks at me, disapprovingly, and says:

You know what you need to do? You need to find a real problem and work on a real problem. People are afraid of working on hard problems because theyre told its impossible. And I think that people are not working hard enough.

I mean, hes going off on me. The man doesnt mince words. Hes a New Yorker like me, one of the reasons that I identify with him.

My interpretation was that I was flattered that he was challenging me to that level. Instead of me taking it negatively, I took that as he respects my intellect so much that hes basically challenging me to pick the hardest problems, the problems that appear to be impossible, and try to solve them.

He finishes his rant, walks up to a blackboard and writes some equations about the big bang on the board, using some clever mathematical tricks. And Im looking, and I think to myself, Wow, thats really interesting.

So a few years went by and it turned out that that thing that he was telling me ended up being the kernel of some ideas surrounding the following paradox: We think that quantum mechanics is something that operates on the microscopic scale. And theres some cases in material systems like metals, superconductors and superfluids where quantum mechanics can operate. But when we start talking about scales of people and buildings and planets, the world is classical, and quantum mechanical effects get washed out.

But this idea that I was inspired to pursue by Leon Cooper claims that at the scale of galaxies, quantum mechanics reappears like a phoenix. And so, theres a chapter in a book called Quantum Galaxies where I talk about this.

One of the hot topics in diversity and inclusion spaces is how we can get more young people of color to have a different image of what a scientist is. You seem to think that being accessible, or cool even, does not clash at all with the image of being smart and scientific. How did you land on this perspective?

Id love to take credit for this, but this really does come from my background.

My family immigrated from Trinidad and Tobago in the late 1970s. I moved to the Bronx at age 8, and was raised there during the 1980s. And so, a lot of what was going on with the development of hip-hop culture was happening right in the neighborhood. And one of the elements in that culture that I dont feel like people have highlighted enough was the importance of having knowledge. That is, on the streets, having knowledge of self and the universe was applauded.

I used to take the bus from my neighborhood to my high school, DeWitt Clinton High School. I used to work on my calculus homework on the ride. And here I am, on the bus, doing my calculus homework. And remember this is the 1980s all sorts of folks would walk through that bus, including some not-too-friendly characters. But a lot of the people on the bus would be all about dropping knowledge. And they would notice me doing my homework.

And from time to time they would engage me, Man, whats up with that mathematics, brother. And I would reply: Im studying derivatives and integration.

And one day a guy said to his friend: This guy is doing supreme mathematics. And from that point on, they basically protected me. Treated me as one of their own, and so I always felt welcome in my community.

This is the same group of guys that encouraged me to go to college. They were like: You need to go to college, get that knowledge and come back.

That sentiment stuck with me. Ive always wanted to bring my knowledge back to the community in whatever way that I could. I never held this idea of a conflict between being authentic and being smart and seeking knowledge. These ideas were never paradoxical growing up in the Bronx.

Now, the media portrayed that differently that our culture was anti-intellectual. But that was not the case where I came from. Being smart has always been a part of being from the streets.

One of the things you emphasize is how to embrace being an outsider. What perspectives can you offer to people who are struggling?

I hope that I said it all in the book! But jokes aside I think Black excellence is a precious idea and must be protected. And in many spaces, Ive found that we can be drawn to safe and comfortable ideas because they feel like they have greater odds of success. One of my career goals is to break this idea its OK being an outsider. Lets embrace it and lean into it. I think thats where our genius lives.

C. Brandon Ogbunu, a New York City native, is a computational biologist at Yale University. His popular writing takes place at the intersection between sports, data science, and culture.

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From Fear of a Black Planet to Fear of a Black Universe - The Undefeated

Newswise Are diamonds even stronger than weve ever imagined? Can other post-diamond phases appear when diamond is subjected to extreme pressures? A team used machine-learned descriptions of interatomic interactions on the 200-petaflop Summit supercomputer at the US Department of Energys (DOEs) Oak Ridge National Laboratory (ORNL) to model more than a billion carbon atoms at quantum accuracy and observe how diamonds behave under some of the most extreme pressures and temperatures imaginable. The results are nothing short of incredible.

The team was led by scientists at the University of South Florida (USF), DOEs Sandia National Laboratories (Sandia), DOEs National Energy Research Scientific ComputingCenter (NERSC), and the NVIDIA Corporation. The researchers found that under extreme conditions, a shock wave strongly compresses the diamond as it passes through and forces it to crack under the pressure.

The study will help scientists better understand how carbon behaves under extreme conditions. This understanding is crucial for inertial confinement fusion, in which hydrogen fuel is kept inside a diamond capsule and nuclear fusion reactions are initiated by compressing the collapsing diamond shell. It is also important for uncovering the internal structure of carbon-rich planetslike Uranusand carbon-rich exoplanets. Exoplanets exist around stars outside of our solar system, and observations suggest they can be rich in diamond and silica.

Observations have shown that some exoplanets consist of carbon-rich constituents, such as methane, which, upon compression, convert to diamond, said Ivan Oleynik, a professor of physics at USF and principal investigator on the project. To understand the structure of these exoplanets, scientists need to understand the behavior of carbon at extreme conditions.

Scientists had believed that under extreme temperatures and pressures, diamond can experience plasticity similar to metals. But as it turns out, diamond experiences a brittle behavior while sustaining its exceptional strength. The team found that these cracks are healed through the formation of amorphous carbon. This carbon is eventually converted into regions of hexagonal diamond, thus explaining the underlying mechanism of diamonds strength.

For this work, the team has been named a finalist for the Association for Computing Machinery Gordon Bell Prize. This prize has been awarded each year since 1987 at the International Conference for High-Performance Computing, Networking, Storage and Analysis (SC). It recognizes outstanding achievements in applying high-performance computing (HPC) to challenges in science, engineering, and large-scale data analytics. The teams results will be presented at SC21, to be held November 1419, 2021, in St. Louis, MO.

Diamonds take the heat

Experiments at Sandias Z Pulsed Power Facility and at Lawrence Livermore National Laboratory (LLNL)facilities capable of creating tens of millions of atmospheres, or 100s of millions of pounds per square inchhave shown that diamond retains extremely high strength even when subjected to enormous compression and heating. It retains this strength up to the state when it should start melting. These experiments involved pressures above several million atmospheres. However, there has been controversy around what actually happens to diamonds under such extreme pressures.

When you load diamond with enormous pressure, it was assumed to turn into a plastic-like state. But we know diamonds are brittle and dont behave in this way, Oleynik said. Our simulations have uncovered an unexpected mechanism of inelastic deformations. Diamond cracks when it is compressed by the enormous shock waves generated at these gigantic compression facilities. These cracks are then reformed during an amorphous-like carbon state inside these cracks. They are then followed by recrystallization into hexagonal stacking faults where the atomic planes are shifted, compared with those in ideal diamond crystals.

Under such extreme conditions, atoms are squeezed together so tightly that only quantum mechanics, which describes how materials behave at the atomic scale, can provide a sufficiently detailed picture of how they interact with one another. But using quantum mechanics to study the dynamics of atoms is computationally expensive.

If you want to simulate something approaching experimental length and timescales, such as micrometers and nanoseconds, you need millions and even billions of atoms and millions of molecular dynamics time steps. But with quantum mechanics, the largest amount of particles you can do is no more than 1,000 atoms. And the largest number of steps is 10,000.

The team made a major breakthrough in describing with quantum accuracy how carbon atoms interact under such enormous pressure and temperature. The team fingerprinted each atom in a diamond using a set of so-calleddescriptors, which were then used to construct an accurate representation of the systems potential energy using powerful machine-learning techniques. This innovative machine-learning approach enabled the team to make predictions of atomic-scale dynamics for a billion atoms to within 3 percent accuracy when compared with extremely precise quantum mechanical calculations.

GPUs illuminate new diamond properties

PhD student Jonathan Willman and postdoctoral associate Kien Nguyen-Cong, both in Oleyniks group at USF, performed the simulations on Summit using a billion-atom sample on the full machine for 24 hours.

Simulating billions of atoms at this nanometer timescale could only be done on Summit. GPU acceleration was the key to achieving these results, Oleynik said. Our team made a major algorithmic breakthrough that allowed our GPU-enabled code to run one hundred times faster than it does on CPU-only machines.

In these billion-atom simulations, the team observed for the first time the shock wave propagation in micrometer-thick diamond at fine resolution, down to the atomic scale. This allowed the team to observe details of diamond cracking and reforming, as well as complex interference patterns created by multiple local sound waves initiated at the crack tips.

We couldnt see this before because we had never done such grand-scale simulations, Oleynik said. The cross section of the diamond sample the team used in simulations is 100 by 100 nanometers and 1 micronor 1,000 nanometersin length.

Running the simulations at such a grand scale is important because now we can achieve high fidelity, and we can say for certain that our results are close to reality, Oleynik said.

Reaching an unknown phase of carbon

Thanks to Summit, the team also has a better understanding of why diamonds havent been transformed to the so-called BC8 high-pressure, post-diamond phase in billion-dollar experiments at the National Ignition Facility (NIF) at LLNL.

These experiments pursued conventional thinking of concerted transformation of atoms from a diamond lattice to that of the BC8 phase. This phase transition requires overcoming an enormous energy, Oleynik said. Our hypothesis, which was brilliantly confirmed in our billion-atom simulations, is that the liquid-like, amorphous carbon can facilitate the nucleation of the BC8 phase. This provides a viable pathway for synthesis of this post-diamond phase. Within the NIF Discovery Science program, we are working with our experimental collaborators to confirm our predictions.

The team plans to extend their simulations to even bigger, trillion-atom systems using emerging exascale HPC systems. These include the nations first exascale supercomputer, Frontier at the Oak Ridge Leadership Computing Facility(OLCF), a DOE Office of Science user facility located at ORNL.

Such tour de force simulations will provide even deeper insight into mystery of diamond rain upon compression of methane inside of ice giants Uranus and Neptune, Oleynik said. The beauty of these simulations is that we can see how nature responds to these extreme pressures and temperatures at the atomic level. We can also see how individual atomic motions combine together in a collective macroscopic behavior, which can then be observed in state-of-the art experiments.

The team members include Jonathan Willman, Kien Nguyen-Cong, and Ivan Oleynik from USF; Stan Moore, Mitchell Wood, and Aidan Thompson from Sandia; Rahulkumar Gayatri from NERSC; and Evan Weinberg from the NVIDIA Corporation.

Sandia is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for DOEs National Nuclear Security Administration (NNSA).

The research is supported by NNSA; the Exascale Computing Project, a collaborative effort of the DOEs Office of Science and NNSA; and DOEs Advanced Scientific Computing Research Leadership Computing Challenge and Innovative and Novel Computational Impact on Theory and Experiment awards. This research used resources of NERSC and the OLCF.

Related Publication: Nguyen-Cong, Kien, Jonathan T. Willman, Stan G. Moore, Anatoly B. Belonoshko, Rahulkumar Gayatri, Evan Weinberg, Mitchell A. Wood, Aidan P. Thompson, and Ivan I. Oleynik. Billion Atom Molecular Dynamics Simulations of Carbon at Extreme Conditions and Experimental Time and Length Scales. Paper to be presented at SC21: The International Conference for High Performance Computing, Networking, Storage and Analysis, St. Louis, MO, November 2021.

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Team Earns Gordon Bell Prize Finalist Nomination for Simulating Carbon at Extreme Pressures and Temperatures - Newswise

Did you know Bo once had his own video games?

Bo Jackson, a former NFL running back for the Los Angeles Raiders and Major League outfielder, is the only player to be named a Pro Bowler in football and All-Star in baseball. So, in 1990, American toy manufacturer Tiger Electronics released a handheld game allowing users to play with Jackson on both the football and baseball fields. The next year, Nintendo dropped Bo Jacksons Hit and Run for Game Boy and Bo Jackson Baseball for the Nintendo Entertainment System.

Yet his trio of games likely wouldnt have been possible without the virtual stardom he garnered in 1989s Tecmo Bowl, the first console game to earn a license from the NFL to feature players by name, image and likeness. To this day, Jackson in Tecmo Bowl and 1991s Tecmo Super Bowl is considered one of the greatest video game avatars, along with Michael Vick from Madden NFL 2004.

Madden was first released on PC in 1988 during Jacksons second season in the NFL. But due to licensing issues and a hip injury during the 1990 NFL season that forced his early retirement from football, Jackson never appeared in Madden during his playing days. It wasnt until 2014 that Jackson made his Madden debut as a special-edition player in the Ultimate Team game mode.

On Wednesday, EA Sports announced that not only will Jackson return to the game for the first time since Madden NFL 15, but hell also receive the honor of becoming a Madden cover athlete. Nearly 35 years after his NFL career began in 1987, Jackson will grace a special digital cover of Madden NFL 22. And beginning Friday, gamers will once again be able to play with him virtually. EA Sports also teamed up with Nike to revisit the sportswear companys famous Bo Knows ad campaign by incorporating a digitally rendered version of his signature shoe, the Nike Air Bo Turf, into the game.

EA Sports

Jackson is the seventh running back to be named a Madden cover athlete, following Eddie George (Madden 2001), Marshall Faulk (Madden 2003), Shaun Alexander (Madden 2007), Peyton Hillis (Madden 12), Adrian Peterson and Barry Sanders (both Madden 25).

Before the cover unveiling, The Undefeateds Aaron Dodson caught up with Jackson to talk about his Tecmo Bowl days, how Bo Knows came to life, his Madden return and more.

This conversation has been edited for clarity and length.

What does it mean to you to finally be a cover athlete for the game, 35 years after your career began?

This has been in the works off and on for years. The time had to be right for my brand. Working with the Madden people to iron things out, dot all the is, cross all the ts once we got that done, the rest was just going for it. I figured that, somewhere in my past, I did something right in order to still be looked at as one of the iconic athletes from over 30 years ago. Madden still thinks enough of me to do something like this.

Your video game legacy dates back to 1989 when you became the star of Tecmo Bowl. What was it like seeing yourself virtually back then?

I still see myself in Tecmo Bowl. Ive still got the video game. Ive still got the machine to play it on. But its in a box somewhere in storage. Its iconic. It really makes me feel good that I have grown men in their 40s saying, Hey, my cousin and I got into the biggest fight of our lives because we both wanted to be you in Tecmo Bowl when we were young. So our parents took the game and my dad locked it up in his tool cabinet. We couldnt play with it for a month because the fight was so intense. I hear that a lot. When Im at sports memorabilia shows, people come up with that video game. They say, I still got the machine to play it on. My kids play it. My grandkids play it and everybody still argues about who is gonna be Bo Jackson. Tecmo Bowl that was a lot of technology back then. You look at it now and its like, Wow, thats an antique.

Is it true that youve never played Tecmo Bowl?

I have never played Tecmo Bowl. Thats the Gods honest truth. I have watched people play it a lot. But I knew what I could do. I knew what the Tecmo Bowl man could do. It gives me pleasure to listen to people compliment me from that game.

Part of your video game return to Madden includes celebrating Nikes iconic Bo Knows campaign. Take us back to the beginning. How did the brand present the idea of Bo Knows to you?

We came across Bo Knows accidentally. Directors, writers, sketchers we were sitting around going over some storyboards for our next shoot. We wanted to cut it down because it was a little too long. Everybody was giving their opinion on this and that. I just said, Why dont we do this? Why dont we move this over here, put this here, combine it and cut out about five or six seconds? They looked at me and said, Wow. Thatll probably work. Then somebody across the table looked at me and said, Bo Knows! And it stuck. Nobody sat down and racked their brains or stayed up all night thinking of that catchphrase. It just happened sitting around the war table going over shoots.

Before you got a signature shoe, the Nike Air Bo Turf, in 1990, you headlined the Nike Air Trainer 3, which became known as your shoe. What memories do you have surrounding the Air Trainer 3?

Well, Ill put it to you like this. In 1969, when I was in the first grade growing up in rural Alabama, during the winter, it was in the mid-30s outside. And I had to go to school barefoot. No shoes. Im not saying this for sympathy or as a sob story. But I can remember my brother standing a block away from the house. Im at the front door. My sister was standing a block away from my brother and my other sister was at the bus stop. When my sister at the bus stop saw the bus top the hill a couple of blocks away, she would yell to my other sister, who would yell to my brother, and my brother would yell to me. Then Id take off out the door barefoot. And by the time my brother got to my first sister, I wouldve caught him already. By the time we got to the bus stop, Im 15, 20 yards in front of my brother and sister. From going to school barefoot during the winter of 69 to growing up and having a sneaker inspired by me I was blessed.

After 30 some odd years, people still brag about that shoe and collect that shoe. A couple of weeks ago, a good friend of mine, Anthony Anderson, the comedian, he texts me, Hey, Bo! Im doing a show about all my sneakers. I cant find your Air Trainers. I need a pair of your shoes! It just so happened I had a pair sitting in my office. I said, Hey, well, I got a pair here. I can just send them to you. Its moments like that where I sit back and go, Wow.

EA Sports

This NFL season, New York Giants running back and Nike athlete Saquon Barkley received his own version of the Air Trainer 3. How did it feel to see him pay homage to you through the sneaker?

I blessed him with those shoes. It was like me saying, Grasshopper, its your time now to carry this torch. And you have to carry it well. I know that he will do a good job of that. Saquon is a good kid. He reminds me a lot of myself. Runs with power and has his head on straight. Thats the thing that impresses me most. Its not his stats. I love the way he carries himself.

There will always be one Bo Jackson. But when you reflect upon the NFL running backs whove come after you, which ones remind you most of yourself?

I can only think of two Saquon and Derrick Henry on the brute strength, power and knowing how to navigate around the field and defense. They dont necessarily have the speed I had. But they have made it work for them. They are very successful at what they do. And thats why theyre looked at as top of the top running backs in the game right now.

When you look back at your career, whats one play you made that you feel couldve come out of a video game?

The one that nobody talks about except Denver Broncos fans is when we went to Denver and I went through their defense on one play like a hot knife through butter. Not bragging, but its just the fact being the size that I was then and how low I learned in college to run behind my pads. Which means you would never catch me upright running unless I had someone 5 or 6 yards behind me trying to chase me. But when I was up in traffic, in the thick of things, it only took me one time to realize that not running behind your pads is bad for you. I cant think of the gentlemans name, but it was a linebacker from the Cardinals when they were in Phoenix. He blew me up. He hit me on the 6- or 7-yard line and dropped me on the 2. He helped me get up and said, Hey, Bo, look, you need to make me earn my check. You need to run harder. Im looking at him like, You done lost your damn mind. Im not going up in that hole no more. The next play, I bounced it outside and used my speed.

EA Sports

Editors note: In the fourth quarter of a game between the Raiders and Broncos on Dec. 2, 1990, Jackson scored a 62-yard rushing touchdown, breaking five tackles en route to the end zone. He finished the afternoon with 13 carries for 117 yards and two scores.

That [Denver] game, once I got through the linemen, I ran over a linebacker, jumped over somebody else. And if Im not mistaken, I hit their All-Pro linebacker, [Karl] Mecklenburg, and outran the defensive back to the goal line. Thats one play that stands out to me because I had to do everything from make somebody miss, jump, get low and go for 60 yards for a touchdown.

What went through your mind when you saw yourself on the Madden cover?

I just sat back and said, Man, you still got it. I did something right. And thats what I preach to guys like Derrick Henry and Saquon Barkley: Do it right. If you do it right the first time, you will be remembered forever.

The Madden curse cant affect you at this point, right?

The Madden curse? [Laughs.] It cant affect me.

You didnt play with yourself in Tecmo Bowl. Are you gonna play with yourself in Madden?

I dont know. But the thing that Im doing right now is spending a lot of time with my new grandson. So Ill probably get the game and save it for him. But I am looking forward to it coming out. Believe you me, I will have my case of Madden games to give out for Christmas presents.

Aaron Dodson is a sports and culture writer at The Undefeated. He primarily writes on sneakers/apparel and hosts the platforms Sneaker Box video series. During Michael Jordans two seasons playing for the Washington Wizards in the early 2000s, the Flint Air Jordan 9s sparked his passion for kicks.

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Bo Jackson makes video game history again with his first Madden cover - The Undefeated