Article written: 20 May , 2018 by Matt Williams
Posted on 05/21/2018 5:54:58 PM PDT by LibWhacker
Article written: 20 May , 2018 by Matt Williams
Neutron stars are famous for combining a very high-density with a very small radius. As the remnants of massive stars that have undergone gravitational collapse, the interior of a neutron star is compressed to the point where they have similar pressure conditions to atomic nuclei. Basically, they become so dense that they experience the same amount of internal pressure as the equivalent of 2.6 to 4.1 quadrillion Suns!
In spite of that, neutron stars have nothing on protons, according to a recent study by scientists at the Department of Energy’s Thomas Jefferson National Accelerator Facility. After conducting the first measurement of the mechanical properties of subatomic particles, the scientific team determined that near the center of a proton, the pressure is about 10 times greater than the pressure in the heart of a neutron star.
The study which describes the team’s findings, titled “The pressure distribution inside the proton“, recently appeared in the scientific journal Nature. The study was led by Volker Burkert, a nuclear physicist at the Thomas Jefferson National Accelerator Facility (TJNAF), and co-authored by
Cross-section of a neutron star. Credit: Wikipedia Commons/Robert Schulze
Basically , they found that the pressure conditions at the center of a proton were 100 decillion pascals – about 10 times the pressure at the heart of a neutron star. However, they also found that pressure inside the particle is not uniform, and drops off as the distance from the center increases. As Volker Burkert, the Jefferson Lab Hall B Leader, explained:
“We found an extremely high outward-directed pressure from the center of the proton, and a much lower and more extended inward-directed pressure near the proton’s periphery… Our results also shed light on the distribution of the strong force inside the proton. We are providing a way of visualizing the magnitude and distribution of the strong force inside the proton. This opens up an entirely new direction in nuclear and particle physics that can be explored in the future.”
Protons are composed of three quarks that are bound together by the strong nuclear force, one of the four fundamental forces that government the Universe – the other being electromagnetism, gravity and weak nuclear forces. Whereas electromagnetism and gravity produce the effects that govern matter on the larger scales, weak and strong nuclear forces govern matter at the subatomic level.
Previously, scientists thought that it was impossible to obtain detailed information about subatomic particles. However, the researchers were able to obtain results by pairing two theoretical frameworks with existing data, which consisted of modelling systems that rely on electromagnetism and gravity. The first model concerns generalized parton distributions (GDP) while the second involve gravitational form factors.
Quarks inside a proton experience a force an order of magnitude greater than matter inside a neutron star. Credit: DOE’s Jefferson Lab
Patron modelling refers to modeling subatomic entities (like quarks) inside protons and neutrons, which allows scientist to create 3D images of a proton’s or neutron’s structure (as probed by the electromagnetic force). The second model describes the scattering of subatomic particles by classical gravitational fields, which describes the mechanical structure of protons when probed via the gravitational force.
As noted, scientists previously thought that this was impossible due to the extreme weakness of the gravitational interaction. However, recent theoretical work has indicated that it could be possible to determine the mechanical structure of a proton using electromagnetic probes as a substitute for gravitational probes. According to Latifa Elouadrhiri – a Jefferson Lab staff scientist and co-author on the paper – that is what their team set out to prove.
“This is the beauty of it. You have this map that you think you will never get,” she said. “But here we are, filling it in with this electromagnetic probe.”
For the sake of their study, the team used the DOE’s Continuous Electron Beam Accelerator Facility at the TJNAF to create a beam of electrons. These were then directed into the nuclei of atoms where they interacted electromagnetically with the quarks inside protons via a process called deeply virtual Compton scattering (DVCS). In this process, an electron exchanges a virtual photon with a quark, transferring energy to the quark and proton.
The bare masses of all 6 flavors of quarks, proton and electron, shown in proportional volume. Credit: Wikipedia/Incnis Mrsi
Shortly thereafter, the proton releases this energy by emitting another photon while remaining intact. Through this process, the team was able to produced detailed information of the mechanics going on in inside the protons they probed. As Francois-Xavier Girod, a Jefferson Lab staff scientist and co-author on the paper, explained the process:
“There’s a photon coming in and a photon coming out. And the pair of photons both are spin-1. That gives us the same information as exchanging one graviton particle with spin-2. So now, one can basically do the same thing that we have done in electromagnetic processes — but relative to the gravitational form factors, which represent the mechanical structure of the proton.”
The next step, according to the research team, will be to apply the technique to even more precise data that will soon be released. This will reduce uncertainties in the current analysis and allow the team to reveal other mechanical properties inside protons – like the internal shear forces and the proton’s mechanical radius. These results, and those the team hope to reveal in the future, are sure to be of interest to other physicists.
“We are providing a way of visualizing the magnitude and distribution of the strong force inside the proton,” said Burkert. “This opens up an entirely new direction in nuclear and particle physics that can be explored in the future.”
Perhaps, just perhaps, it will bring us closer to understanding how the four fundamental forces of the Universe interact. While scientists understand how electromagnetism and weak and strong nuclear forces interact with each other (as described by Quantum Mechanics), they are still unsure how these interact with gravity (as described by General Relativity).
If and when the four forces can be unified in a Theory of Everything (ToE), one of the last and greatest hurdles to a complete understanding of the Universe will finally be removed.
Until I hit 71, mine were up quarks.
“Basically , they found that the pressure conditions at the center of a proton were 100 decillion pascals – about 10 times the pressure at the heart of a neutron star. ”
Which leads to the obvious question: what is the pressure at the center of a proton at the center of a neutron star?
Inquiring minds want to know!
Like the universe thunk itself up.
I don’t think so, thank God.
Except for charge, protons and neutrons are very similar, so Id’s say the pressures would be similar, too.
It’s amazing that we can even attempt to measure the pressures inside a proton.
The first measurement of a subatomic particle’s mechanical property reveals the distribution of pressure inside the proton.
NEWPORT NEWS, VA – Inside every proton in every atom in the universe is a pressure cooker environment that surpasses the atom-crushing heart of a neutron star. That’s according to the first measurement of a mechanical property of subatomic particles, the pressure distribution inside the proton, which was carried out by scientists at the Department of Energy’s Thomas Jefferson National Accelerator Facility.
The nuclear physicists found that the proton’s building blocks, the quarks, are subjected to a pressure of 100 decillion Pascal (1035) near the center of a proton, which is about 10 times greater than the pressure in the heart of a neutron star. The result was recently published in the journal Nature.
“We found an extremely high outward-directed pressure from the center of the proton, and a much lower and more extended inward-directed pressure near the proton’s periphery,” explains Volker Burkert, Jefferson Lab Hall B Leader and a co-author on the paper.
Burkert says that the distribution of pressure inside the proton is dictated by the strong force, the force that binds three quarks together to make a proton.
“Our results also shed light on the distribution of the strong force inside the proton,” he said. “We are providing a way of visualizing the magnitude and distribution of the strong force inside the proton. This opens up an entirely new direction in nuclear and particle physics that can be explored in the future.”
Once thought impossible to obtain, this measurement is the result of a clever pairing of two theoretical frameworks with existing data.
First, there are the generalized parton distributions. GPDs allow researchers to produce a 3D image of the proton’s structure as probed by the electromagnetic force. The second are the gravitational form factors of the proton. These form factors describe what the mechanical structure of the proton would be if researchers could probe the proton via the gravitational force.
The theorist who developed the concept of gravitational form factors in 1966, Heinz Pagels, famously observed in the paper detailing them that there was “very little hope of learning anything about the detailed mechanical structure of a particle, because of the extreme weakness of the gravitational interaction.”
Recent theoretical work, however, has connected GPDs to the gravitational form factors, allowing the results from electromagnetic probes of protons to substitute for gravitational probes.
“This is the beauty of it. You have this map that you think you will never get,” said Latifa Elouadrhiri, a Jefferson Lab staff scientist and co-author on the paper. “But here we are, filling it in with this electromagnetic probe.”
The electromagnetic probe consists of beams of electrons produced by the Continuous Electron Beam Accelerator Facility, a DOE Office of Science User Facility. These electrons are directed into the nuclei of atoms, where they interact electromagnetically with the quarks inside protons via a process called deeply virtual Compton scattering.
In the DVCS process, an electron enters a proton and exchanges a virtual photon with a quark, transferring energy to the quark and proton. A short time later, the proton releases this energy by emitting another photon and continues on intact. This process is analogous to the calculations Pagels performed for how it would be possible to probe the proton gravitationally via a hypothetical beam of gravitons. The Jefferson Lab researchers were able to exploit a similarity between the well-known electromagnetic and hypothetical gravitational studies to get their result.
“There’s a photon coming in and a photon coming out. And the pair of photons both are spin-1. That gives us the same information as exchanging one graviton particle with spin-2,” says Francois-Xavier Girod, a Jefferson Lab staff scientist and co-author on the paper. “So now, one can basically do the same thing that we have done in electromagnetic processes — but relative to the gravitational form factors, which represent the mechanical structure of the proton.”
The researchers say the next step is to apply the technique to even more precise data that will be available soon to reduce the uncertainties in the current analysis and begin working toward revealing other mechanical properties of the ubiquitous proton, such as the internal shear forces and the proton’s mechanical radius.
Finally an explanation for Poprocks that even I can understand!
Of course what these scientists are calling pressure may not even equate with the definition of pressure, ala gravitational crushing.
That is a most interesting theory.
But what if black holes were actually bigger inside than they appear to be from the outside? Like a TARDIS? We observe it and it appears to be this finite object (or area of space) within the vast space of our ever-expanding universe. Very small in comparison. But for an observer inside the black hole it appears to him as an incredibly vast ever-expanding universe every bit as vast as ours appears to us.
Due to that special nature of the event horizon (for lack of a better description) we cannot see the universe inside of it and he cannot see the universe outside, our universe.
You theory doesn’t sound so crazy now does it? lol
To me, it’s so incredible. I would never have dreamed the concept of pressure even applies to the interior of a proton. It would have been like asking me what the pressure is inside a moment of time. Probably why I’m not a physicst.
Isn’t it interesting that as time goes on, and we learn more about the elemental functions of the Universe, the less we actually understand ?
Are you sure ?
On the assumption that the Big Bang Theory is true, it should be easy to determine the center of the Universe. If so, then where is it ?
It’s like an infinity onion.
Who cares?
Inside the big black hole.
And the whole thing smells.
Well, It makes me tear-up. When I spend too much time thinking about it.
Scientist: How big is the Universe?
Mechanic: In SAE or METRIC ?
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