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First Measurement of Distribution of Pressure Inside a Proton (phys.org)

Posted by BeauHD on from the under-pressure dept.

Okian Warrior shares a report from Phys.Org: 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.

89 of 174 comments (clear)

  1. Is there energy to be had here? by MichaelSmith · · Score: 4, Interesting

    Is Subnuclear fission a possibility?

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    1. Re:Is there energy to be had here? by LordHighExecutioner · · Score: 5, Funny

      If there is, it will be taxed.

    2. Re:Is there energy to be had here? by Anonymous Coward · · Score: 2, Informative

      I'm not a physicist but theoretically it should be possible. Quarks make up only 1% of the mass of a proton [1], the remaining 99% is the binding energy. If we could harvest that, we could get even more energy per kg of fuel than from nuclear fission.

      [1] https://van.physics.illinois.edu/qa/listing.php?id=30159

    3. Re:Is there energy to be had here? by beachmike · · Score: 1

      Yes, using the not yet developed nuclear proton micropile reactor.

    4. Re: Is there energy to be had here? by Anonymous Coward · · Score: 1

      Except quarks cannot exist by themselves.
      So at best you can temporarily MAYBE coax them into quark-antiquark pairs.

      But if you got antiquarks ⦠there is a vastly more energetic process ...

      Maybe if you want to recycle the antiquarks.
      But I don't know if turning 2 trios into 3 pairs would even release any energy ...

    5. Re:Is there energy to be had here? by Zorpheus · · Score: 4, Interesting

      Only if quarks could exist in a state of lower energy than inside a proton. I don't think such a state exists, so the answer is no.
      What is possible is matter-antimatter annihilation. So if we found a cheap source of antiprotons ...

    6. Re: Is there energy to be had here? by Anonymous Coward · · Score: 1

      my understanding is that a single quark "cannot exist" mostly because if there was ever a single quark, there's enough energy in the system to make more quarks just pop into existence to keep it company. If they pop into existence, then they can just as easily pop out of existence. So perhaps a process where a proton is split (releasing energy) and the quarks fly off (and almost immediately pair up to their partners out of nothing), or disappear into nothing (perhaps releasing even more energy).

    7. Re:Is there energy to be had here? by pezezin · · Score: 5, Interesting

      Maybe. Some physicists have proposed the existence of "electroweak stars", where energy would be generated from a process know as "electroweak burning" where quarks are converted to leptons: https://en.wikipedia.org/wiki/...

    8. Re:Is there energy to be had here? by Anonymous Coward · · Score: 5, Interesting

      Nuclear fission is possible because there can exist free residual nuclei which in sum hold less energy than starting large fissile nucleus. It is a sort of balanced equation of materials and energy, where on both sides of equation you have all materials accounted for, but in terms of energy, you get surplus free energy on resulting side.

      In case of nucleons however, we don't have such equation, because as far as we know, in nature's supply, we only have protons and neutrons, and they are approximately same size. If quarks could exist in free form, or build some stable particles smaller than protons and neutrons, we'd could have a theoretical chance to rob protons or neutrons of a part of their energy.

    9. Re:Is there energy to be had here? by lgw · · Score: 4, Interesting

      Is Subnuclear fission a possibility?

      Well, the proton is already the lowest energy level. The binding energy for hadrons works a bit differently than for atoms - pulling a quark out of a photon requires so much energy that new quarks are created and the quarks remain bound in particles. Free neutrons, OTOH, decay with a half life of ~14 minutes IIRC, when they aren't packed in tightly with other protons and neutrons.

      TFS is a bit odd too. Of course the pressure in a proton is greater than in a neutron star - when the internal pressure in a start exceeds the pressure inside a neutron, the neutrons collapse and you get a black hole. And protons and neutrons are reasonably similar.

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    10. Re:Is there energy to be had here? by jellomizer · · Score: 1, Interesting

      The issue is the power that we use is mostly mechanical energy, which then gets converted to electromagnetic.
      There is significant power loss when ever we change energy (well it isn't lost, it is converted into an unusable form, such as sound, or heat dissipation).
      Even with protonic fission we are still heating up water to create pressure difference to move a turbine that spins magnets which pushes and yanks electrons around.

      We also have chemical energy from batteries and solar cells which more directly creates electricity without going to mechanical energy.
      So the dense energy sources such as Fossil fuel or nuclear energy needs a mechanical overhead.

      The problem isn't as much as how much energy we need, but the expense (Environmental, Economic, Morally) of creating the energy is. Much of the Glamor of the 1950's vision of the future, didn't account for the price of oil rising, radioactive waste of nuclear energy, wars, safety concerns about getting the energy and the fact that people in general disagree with each other. Those Utopia visions of the future can be a Dystopia to someone else.

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    11. Re:Is there energy to be had here? by Applehu+Akbar · · Score: 2

      Is Subnuclear fission a possibility?

      You would have to identify a usable lower energy state that you could 'fission down' to.

    12. Re:Is there energy to be had here? by Wulf2k · · Score: 1

      "radioactive waste of nuclear energy,"

      I think you mean "more free energy from nuclear energy".

      All the nasty types of waste are really just great sources of fuel that nobody can tap into because politics won't let them build a reactor design from this century.

    13. Re:Is there energy to be had here? by Wrath0fb0b · · Score: 2

      No and yes.

      Yes, it's possible and indeed 'subnuclear fission' is already done in particle accelerators, you can smash a proton into a quark plasma -- although at those energies you are spontaneously generating new particle/anti-particle pairs so the idea of discrete particle identities makes a bit less sense.

      No, there's no energy to be had there. The proton is stable for at least 10**34 years (age of the universe is 10**10 year) and so any such fission will necessarily require you put in more energy than you get out.

    14. Re:Is there energy to be had here? by tinkerton · · Score: 1

      when the internal pressure in a start exceeds the pressure inside a neutron, the neutrons collapse and you get a black hole

      I thought that the reasoning should be ''when the internal pressure in a star exceeds the pressure inside a neutron then another interesting object will be created which may look like a single superneutron, but before that happens the star will turn into a black hole for different reasons.

    15. Re:Is there energy to be had here? by lgw · · Score: 2

      You may well be right. However, I suspect a quark star only exists inside a black hole, which would make it hard to verify. (Much like the theory that F6 tornadoes exist, but only inside an F5, so how can you ever prove it?)

      --
      Socialism: a lie told by totalitarians and believed by fools.
    16. Re:Is there energy to be had here? by Anonymous Coward · · Score: 5, Funny

      So if we found a cheap source of antiprotons ...

      Start an Internet campaign that protons are racists. You'll have more antiprotons than you know what to do with.

    17. Re:Is there energy to be had here? by fazig · · Score: 2

      Reminds me of that Futurama episode when the Professor turned the robot into a human through a process called reverse fossilization. Explaining that he discovered that normal fossilization was turning living flesh and bone into minerals. And after realizing that it was a simple matter reversing the process.

      So after realizing E = mc it's just converting all of it back to energy, yes? It's that simple, right? Fine. But how do you actually do it?

    18. Re:Is there energy to be had here? by sexconker · · Score: 2

      Basically. Most "nuclear waste" is the equivalent of someone throwing away a ketchup bottle that's half full because mom said not to shake, tap, or invert the bottle to get the rest out.

    19. Re:Is there energy to be had here? by cyberchondriac · · Score: 1

      And then we can create our zombie army!

      Well.. close enough I guess.

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      Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
    20. Re:Is there energy to be had here? by Impy+the+Impiuos+Imp · · Score: 1

      It sure what this boilerplate post is about, but cheaper, massive amounts of energy, especially non-polluting, is a valuable goal.

      With cheap enough energy, you can cheaply boil ocean water to distill fresh for people around the world.

      --
      (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
    21. Re:Is there energy to be had here? by kiminator · · Score: 4, Interesting

      I'm assuming by this term you mean a fission process which occurs within protons or neutrons, rather than within atomic nuclei. The answer to that is no, no matter how you slice it.

      A short explanation for this is simply that quarks are stable particles, like electrons. It's not possible for there to be lower-mass versions of the up/down quarks which we haven't yet observed. There are certainly higher-energy versions of these same particles, but quarks themselves cannot exist except when bound to one another, either in mesons (two quarks) or baryons (three quarks, like protons and neutrons).

      The reason why quarks can't exist alone is that if you take a meson and try to pull apart the two quarks that make it up, it takes so much energy that a quark/anti-quark pair is created, so instead of pulling a meson apart to get two quarks, you end up with two mesons. Similar things happen if you try to pull a quark out of a baryon (like a proton): you end up with a baryon and a meson instead of a meson and a free quark.

      In the end, the proton is the lowest-energy stable state that a collection of three quarks can wind up in (mesons are all unstable, and rapidly decay into either electrons/positrons and neutrinos if they have charge, photons if they do not). But higher-mass baryons, of which there are a great many, will decay into other baryons and collections of particles. This process of more massive baryons decaying into protons/neutrons is probably the closest thing to "subnuclear fission" that exists.

    22. Re:Is there energy to be had here? by Dragonslicer · · Score: 2

      If quarks could exist in free form, or build some stable particles smaller than protons and neutrons, we'd could have a theoretical chance to rob protons or neutrons of a part of their energy.

      Minor pedantry: mesons are made up of only two quarks (technically, a quark and an antiquark), and the lightest mesons, the pions, are lighter than protons and neutrons.

      Pions are only about 15% of the mass of protons, so based on mass, you could get quite a bit of energy out of the conversion of protons and neutrons. The problem is that you would need to convert a quark to an antiquark, which is a bit tricky.

    23. Re:Is there energy to be had here? by Dragonslicer · · Score: 1

      So after realizing E = mc it's just converting all of it back to energy, yes? It's that simple, right? Fine. But how do you actually do it?

      It is simple, you just add antimatter and use the photons produced by the annihilation.

      Getting the antimatter might be difficult, but the process is simple.

    24. Re:Is there energy to be had here? by fazig · · Score: 1

      Indeed. It's so simple.

    25. Re:Is there energy to be had here? by Dragonslicer · · Score: 1

      Absolutely. Neutrons can decay to a Proton and Electron and extra energy. This is fission of a nuclear particle which I think is what you mean by Subnuclear fission.

      Not really. Fission implies splitting of parts that are already there. Neutrons aren't made of protons and electrons; that was the hypothesis at one point, but observations of particle spin didn't match the predictions you would get with a neutron that contains a proton and an electron. Neutrons become protons and electrons (and antineutrinos) by converting a down quark to an up quark.

    26. Re:Is there energy to be had here? by BitterOak · · Score: 4, Informative

      The problem is that you would need to convert a quark to an antiquark, which is a bit tricky.

      You can't turn quarks into anti-quarks, and this is directly related to the conservation of baryon number. Protons and neutrons have baryon number 1 each, while mesons have baryon number 0, and as far as we can tell, baryon number is a strictly conserved quantity. Since protons and neutrons are the lightest baryons, the "sub-nuclear" fission described is, as far as we know, not possible under the laws of physics as we understand them.

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    27. Re:Is there energy to be had here? by qeveren · · Score: 1

      The problem there is that in order to take a nibble of that binding energy you have to find a lower energy state for everything to drop into, and there doesn't seem to be one available.

      --
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    28. Re:Is there energy to be had here? by sjames · · Score: 2

      It's worse. The "bottle" is typically 95% full when we throw it away.

    29. Re:Is there energy to be had here? by Dragonslicer · · Score: 2

      Yeah, I was intentionally understating it. C'mon, I wouldn't be on Slashdot if I wasn't sarcastic all the time.

      I guess you could convert a proton (uud) and an antineutron (u'd'd') to three pions, and that would conserve baryon number. Two of those pions might annihilate and give you even more energy. Of course, at that point, you might as well just get your energy from neutron/antineutron or proton/antiproton annihilation and skip the extra steps.

    30. Re:Is there energy to be had here? by TomGreenhaw · · Score: 1

      If I had mod points, I would mod your response up because its thought provoking. It does however have the makings of an interesting debate.

      By definition - Fission: the action of dividing or splitting something into two or more parts. By saying "Fission implies splitting of parts that are already there." you are making an arbitrary decision on the meaning of fission. At best this is semantics and splitting hairs. Please provide a generally accepted reference that shows proof that fission only involves the separation of indivisible components.

      "Neutrons aren't made of protons and electrons" - I think you're trying to say that a proton is not a separate proton and electron somehow bound together and on that I agree. Your statement is misleading though because its like saying "omelettes aren't made of eggs and cheese". They are however typical decay products of a neutron. Its interesting to note that this process is reversible with the observation of electron capture.

      "Neutrons become protons and electrons (and antineutrinos) by converting a down quark to an up quark." I recommend you qualify that statement by adding: "It is generally accepted with the successful theory of the standard model that..." If I took the position that quarks are imaginary things that serve as an analogy, you would have a difficult time proving otherwise. Their existence is purely inferred by observations and whose existence is rooted in equations where the math works out. Don't get me wrong, the standard model is incredibly useful, but it is not unlike the Bohr model of electrons orbiting a nucleus the math works and its easy to draw, but that's not truly ho nature works. In any case we would just shift the argument above for a one that says down quarks decay into up quarks electrons and binding energy that is released in some form.

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    31. Re:Is there energy to be had here? by AutodidactLabrat · · Score: 1

      Will someone PLEASE have Kirk Sorensen's fake slashdot accounts cancelled?
      In the name of humanity?

    32. Re:Is there energy to be had here? by tinkerton · · Score: 1

      I regularly notice that black holes are used as some kind of 'structural' mechanism in stars while it's in principle independent of strong forces or the life cycle of a star. Maybe there is a theoretical solution where a huge star becomes a black hole at the start of the lifecycle. From an elementary reasoning the Schwarzschild radius is proportional to mass so a low density cloud which is large enough can already be a black hole.

      In a way the idea of a quark star in a black hole only comes up because we're talking about small black holes :)

  2. How much teen angst is that? by Anonymous Coward · · Score: 1

    And where is there a safe space for those poor quarks?

    (Also, BeauHD, you shmuck: It's 10^35, or write 10e35, not 1035).

    1. Re:How much teen angst is that? by maroberts · · Score: 4, Funny

      And where is there a safe space for those poor quarks?

      (Also, BeauHD, you shmuck: It's 10^35, or write 10e35, not 1035).

      I'm sure Quarks will be safe on DS9

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    2. Re: How much teen angst is that? by Evtim · · Score: 1

      Rule of aquisition 286:
      Safe spaces are not good for business!

  3. Strong force? by Anonymous Coward · · Score: 1

    In thought strong force refers to the force that binds the protons inside the necleus.... Do quarks even need a force holding them together? Like does opposite spin quarks repel each other?

  4. Re: Then why did WTC7 collapse? by Anonymous Coward · · Score: 1

    Its was Trump's fault... duh!

  5. Re:Then why did WTC7 collapse? by Anonymous Coward · · Score: 1

    All these geniuses put together can't figure out why WTC7 collapsed.... hmmm....

    AE911Truth org

    Hey, look!

    It's Rosie "Fire can't melt steel (I'm too dumb to know what a fucking blacksmith is)!" O'Donnell.

  6. to quote marty by sad_ · · Score: 3, Insightful

    heavy

    --
    On a long enough timeline, the survival rate for everyone drops to zero.
    1. Re:to quote marty by Jahoda · · Score: 2

      Weight has nothing to do with it.

  7. 1035? by johannesg · · Score: 5, Informative

    1035 doesn't sound so bad. 10^35 on the other hand...

    1. Re:1035? by Anonymous Coward · · Score: 1

      It’s only missing some zeros....

    2. Re:1035? by ari_j · · Score: 2

      1035 doesn't sound so bad. 10^35 on the other hand...

      For years now, the editors have not understood science. Now, they don't even understand scientific notation.

    3. Re:1035? by Anonymous Coward · · Score: 1

      Exactly. cut and paste didn't respect the font size change. It takes brains to memorize scientific facts (intelligence) and it takes intuition to make use of the information (wisdom).

      We have a lot of intelligent people on the planet, not so many are wise anymore. They are all wise-arses though :)

    4. Re:1035? by OrangeTide · · Score: 1

      A rather short perl script could replace brains in situations like this.

      --
      “Common sense is not so common.” — Voltaire
  8. Jefferson Lab Open Day May 19th by OzPeter · · Score: 5, Informative

    If you are in the Newport News, VA area on Saturday, the Jefferson Lab is having an open day from 9AM to 3PM. https://www.jlab.org/

    Also the press release from the lab itself about the Proton pressure QUARKS FEEL THE PRESSURE IN THE PROTON

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  9. Macroscopic concept? by Anonymous Coward · · Score: 5, Interesting

    Could someone please explain this? I always thought pressure was a more macroscopic concept, related to the force exerted by (many) bouncing particles on a wall, or similar. What is the meaning of pressure within a proton? And what is its meaning? Like density or "edges", I would think macroscopic concepts are no longer valid in that realm.

    1. Re:Macroscopic concept? by CustomSolvers2 · · Score: 4, Informative

      pressure was a more macroscopic concept

      Pressure is force per unit of area and is relevant in any context where an area exists. No matter how small quarks are, they are 3D objects and forces applied on them can be modelled via pressure.

      Like density or "edges"

      Same than before: size doesn't matter for any of this. See the proton as an sphere and the elements inside it having certain distribution.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    2. Re:Macroscopic concept? by CustomSolvers2 · · Score: 1

      you are confusing the macroscopic world with the quantum world.

      You are confusing a specific theory dealing with a specific subset of problems in a specific way with it being absolutely applicable, even over the much more comprehensive theory from which it is supposed to be a part of. If you assume that atomic particles are formed by other smaller particles, the basic principles of general physics (mechanics in this case) would be applicable to them regardless of anything else. Unless you can come up with a justification for that not being the case. Or, in other words, a new geometry where massive non 3D objects can exist outside your imagination (a be targetted by force/pressure).

      --
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    3. Re: Macroscopic concept? by bondsbw · · Score: 1

      Dimension means attribute. When we say "three dimensions in space" we are saying that we need three attributes to describe the concept of location.

      For each attribute of a dimension, we can talk about points (single values) or sizes (ranges of values between points). Therefore point doesn't necessarily mean that the location is specific, only that we are talking about one numeric value for location instead of a range.

      --
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    4. Re:Macroscopic concept? by Smidge204 · · Score: 1

      Or, in other words, a new geometry where massive non 3D objects can exist outside your imagination

      We call this "quantum mechanics" where particles act like waves (and waves act like particles) and things can have momentum but no mass.

      Quarks have mass but no volume. The very concept of "3D objects" vanishes in a puff of mathematics.
      =Smidge=

    5. Re:Macroscopic concept? by CustomSolvers2 · · Score: 1

      described as being point-like

      As explained to others and usually happens everywhere else, it is a matter of context. From a macro-atomic point of view, you might safely assume atoms (or their constituents) are punctual. Or even when analysing them from a point of view where geometry is irrelevant. For example, you can assume that electrons are 1D elements when calculating an electric current or a voltage. But if you want go much deeper, understand why energy/force/pressure is generated at all and individually analyse one electron, you would have to consider mass/dimensions. This article talks about pressure because this is what is being described here (force on a massive object, no matter how small it is). What is useful under certain conditions, might be useless everywhere else. All what matters is making sure that you understand the given context and behave accordingly.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    6. Re:Macroscopic concept? by Smidge204 · · Score: 2

      Your quantum mechanics

      "My" quantum mechanics? As if I came up with it myself...

      There is absolutely no doubt that quantum mechanics is as real and correct as any other aspect of science. It's perhaps one of the best fields there is in terms of predictive power, despite how intangible and counter-intuitive it is. The fact that we're even able to have this interaction is testament to that!

      You seem to be the one trying to shoehorn decades of well established and applied quantum physics into a classical worldview. That's not going to work. Classical physics has been demonstrated to be fundamentally wrong for at least a century now, thanks to Relativity and QM (but we keep it around only because it's "good enough" for everyday use.)

      If you think you have a better theory, that explains everything QM does and more, and can produce the same practical results, you have multiple Nobel prizes and immortality in the annals of human history waiting for you.
      =Smidge=

    7. Re:Macroscopic concept? by CustomSolvers2 · · Score: 1

      Sorry if my attitude wasn't too clear, but I didn't mean any disrespect. I am not interested in discussing about certain issues either. My sole intention was highlighting that the mass-3D-pressure idea is applicable here, regardless of the default assumptions in whatever other context (quantum mechanics or anything else). Hopefully, you will understand my position, that I have already written a lot and that I will better stop it here.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    8. Re:Macroscopic concept? by kiminator · · Score: 2

      You might be right if a proton was merely three quarks. But it turns out that this is not the case: protons are sort of a cloud of quarks, anti-quarks, and gluons. The "three quarks" are known as the valence quarks (they're the only ones that aren't paired with anti-quarks), but only make up a small fraction of the total mass (without looking it up, I think it's something like 5-10%). Nearly all of the rest of the energy is made up a dynamic swarm of particles. The sheer number of particles inside a proton is probably enough to make pressure a sensible concept.

      It also makes sense that the pressure would be above that of a neutron star: if a neutron star's pressure were higher, then you'd expect the protons/neutrons near its core to no longer exist as protons/neutrons, but instead become some other form of matter.

    9. Re: Macroscopic concept? by ceoyoyo · · Score: 2

      Pressure is force per unit area (as so many have pointed out). In a static(ish) system a force in one direction must be balanced by one opposing it. If youâ(TM)ve got a jar of air, the walls of the jar feel pressure from the air molecules hitting them, and oppose that pressure with forces generated from the electromagnetic force holding the glass molecules together.

      Protons must also experience balanced forces, or they would collapse or explode. The inward force is probably mostly the strong force. The outward force is probably a mixture of electromagnetic (the quarks are charged) and degeneracy pressure from Pauli exclusion. Since quarks (the three valence ones and the sea of virtual ones) in a proton are fermions, they canâ(TM)t occupy the same quantum states. Additional particles have to pile into higher energy states, and the result is an outward force thatâ(TM)s actually quite analogous to all those air molecules smashing into the walls of the jar.

  10. Re:Umm, what's doing the pushing? by belg4mit · · Score: 2

    Neutrons stars are a form of degenerate matter resulting from quantum effects (and gravity), it's a perfectly cromulent comparison.

    As others have pointed out, pressure is F/A. If you have a spherical cow in a vacuum at absolute zero standing on top of a pencil balanced on its point, the pencil point is still exerting pressure on the surface underneath.

    --
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  11. Re:Umm, what's doing the pushing? by ledow · · Score: 2

    Any force you like.

    Pressure has nothing to do with atoms bouncing, per se. In fact, at high pressure, in solids, etc. they can't do that at all. They exert a force against other atoms.

    In a gas, sure, the "atmospheric pressure" is the result of atoms moving around each other, but even there - gravity makes the pressure on the bottom of the container greater than the lid. You might not care, it might only be a small difference, but it's still contributing to the pressure on the floor.

    If you have a force exerted on an area, you have a pressure.

  12. Re:Then why did WTC7 collapse? by Anonymous Coward · · Score: 1

    Did you somehow happen to miss the colossal 20-story gash carved out the side of the building caused by humongous chunks of falling debris? Combine that with the other countless compromises in integrity elsewhere and the raging fire, the incredible part isn't that WTC7 collapsed, it's that it stood as long as it did.

  13. Re: Then why did WTC7 collapse? by richy+freeway · · Score: 1, Insightful

    The real question here is : Who gives a fuck?

    That shit happened 17 years ago. Move on already.

  14. Re:Then why did WTC7 collapse? by 50000BTU_barbecue · · Score: 1

    All these truther geniuses that figured out why WTC7 collapsed couldn't figure out the pressure inside a proton... hmmm....

    --
    Mostly random stuff.
  15. "the pressure distribution inside the proton" by grep+-v+'.*'+* · · Score: 1

    So is it pressure (something pushing them together, like it says) or attraction (something pulling them together)? Or something else completely different because they're quarks?

    --
    If the universe is someone's simulation -- does that mean the stars are just stuck pixels?
  16. Great to see JLab in the news. by Headw1nd · · Score: 1

    As a tidewater native, I'm really exited to see this quality of research coming out of Jefferson Lab. It's a great asset to the area.

    1. Re:Great to see JLab in the news. by OzPeter · · Score: 1

      As a tidewater native, I'm really exited to see this quality of research coming out of Jefferson Lab. It's a great asset to the area.

      If only they could turn their expertise to solving pressure waves on I-64

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    2. Re:Great to see JLab in the news. by Immerman · · Score: 1

      "Pressure wave" traffic jams I assume? That's a solved problem - all that remains is to convince drivers to implement the solution, one that every colony ant on the planet already uses: every driver must try to always remain roughly equidistant between the cars in front of and behind them, which causes the waveform to dissipate.

      Ants don't have traffic jams. Humans on the other hand aren't smart enough to avoid them. Riding that guy's bumper isn't going to save you more than a few seconds, at most, but greatly enhances the chance that everyone will get stuck in a traffic jam.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    3. Re:Great to see JLab in the news. by anegg · · Score: 1

      Hmmm. Rather than having everyone switch over to self-driving cars, perhaps what would work here is to have all cars equipped with a collision avoidance/following distance maintenance system with haptic feedback. The technology for maintaining following distances exists, although it is not usually tied to the accelerator with haptic feedback.

      The idea is that your car's accelerator would behave normally until your car got within a speed-determined distance from the vehicle in front of you. At that point your accelerator would require much more force to depress it further. If the distance narrowed because the car ahead slowed down, the accelerator would actually push back, lowering the speed of the car (assuming the driver doesn't override the pedal pushback force). If the distance widened, the resistance to pressure on the pedal would decrease. As long as the driver maintains a slight forward pressure on the accelerator pedal (generally necessary to overcome the return spring on the accelerator anyway) then the car would accelerate/decelerate (slightly) as necessary to maintain the distance at the speed-dependent optimum. If for any reason it was necessary for the driver to accelerate or decelerate despite this causing a departure from the optimum distance, the driver would be able to do so, but with feedback from the vehicle.

      If all cars had the same optimum distance by speed calculation, then it would be easy to drive in heavy traffic while maintaining safe following distances, and the waves would be diminished.

    4. Re:Great to see JLab in the news. by Immerman · · Score: 1

      An interesting idea, except you don't want to maintain a fixed following distance - that's what creates the conditions for pressure waves to exist. You want to dynamically adjust following distance based on how much space you have behind you as well. If there's a bunch of empty space behind you - slow down and spread out - then the person in front of you now has more space behind them, and should do the same thing, etc,etc,etc. Likewise, if there's a bunch of empty space in front of you, and traffic behind, speed up.

      Basically you're trying to "buffer" road space so that the dense sections stretch out to fill the empty sections, rather than traffic moving in clumps, as is typically the case.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  17. Re: Then why did WTC7 collapse? by Bob+the+Super+Hamste · · Score: 1

    If it the engine in my car an aluminum block with cast iron sleeves with water channels around it to keep it cool enough so it doesn't weaken too much to suffer damage from the heating caused by combustion. Is it hard for you to walk and chew gum at the same time?

    --
    Time to offend someone
  18. Size of an electron? by Okian+Warrior · · Score: 1

    You are wrong about quarks being 3D objects

    Every single existing bit (with mass) has 3 dimensions. Any other number of dimensions is only possible in our imagination, not in the physical world.

    Apropos of nothing, what are the dimensions of an electron?

    1. Re:Size of an electron? by CustomSolvers2 · · Score: 1

      Apropos of nothing, what are the dimensions of an electron?

      I think that the context of the current discussion and my point was pretty clear. We are talking about (mechanical) forces and geometries dealing with them. The word "dimension" has different meanings, like many other words, assumed to be properly understood within the given context. The only reasonable misinterpretations of my words I can think of are 4D (3D + time) and 1D/2D (simplistic geometries), all of them used in geometrical/mechanical calculations.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    2. Re:Size of an electron? by CustomSolvers2 · · Score: 1

      Or, by asking a question similar to yours, how do you calculate the pressure on an electron? Which dimensions would you choose to calculate the required area? Or do you consider that you cannot apply pressure on electrons? Or that electrons don't have area? Please, illustrate me.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    3. Re:Size of an electron? by CustomSolvers2 · · Score: 2

      An even more solid argument against the point particle idea: in this specific context, it is simply incongruent. We are precisely talking about the existence of sub-atomic particles, what converts atomic particles into containers, forcibly 3D entities. Even if you could defend their (real world) 1D essence at all, you would have to deny the existence of any sub-atomic element. Additionally and going back to the original discussion: just the mere fact of being inside a container (= necessarily a 3D space) supports the reference to pressure, even in case of considering quarks as 1D elements. The pressure could be applied on the 3D space (empty space or various quarks at the same time) anyway.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
    4. Re:Size of an electron? by DrTJ · · Score: 1

      Oh, this is an interesting question.

      If you by dimension mean size, there is a classical estimate of what radius an electron has. If one starts to put together a small sphere of "continuous" electric charge by moving infinitely small droplets of charge from infinity to the surface of the sphere, and continues to do so until the amount of energy consumed matches the relativistic energy of an electron, mc^2, one ends up with an charged sphere with radius 2.8E-15m.

      However, in modern physics it is close to meaningless to talk about the size of an electron. The electron is considered very elemental, to the point is is modeled by a point charge. Please do not confuse the uncertainty, or the wave function, of an electron with its size. The wave function represents (among other things) the probability distribution of the position of the electron.

      The proton, on the other hand, is not considered elemental (being made of quarks and gluons), or a point charge, and it does seems to have a size about 0.87E-15 m or so.

      Interestingly enough, the classical size of size of the electron far surpasses the modern estimate of the size of the proton.

    5. Re:Size of an electron? by CustomSolvers2 · · Score: 1

      sub-atomic particles

      Not sure if this is the most correct designation, but I guess that what I meant should be clear: particles forming other atomic particles.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
  19. Color force by Okian+Warrior · · Score: 4, Informative

    In thought strong force refers to the force that binds the protons inside the necleus.... Do quarks even need a force holding them together? Like does opposite spin quarks repel each other?

    The color force holds three quarks together in a proton or neutron. Protons have charge, so there's significant repulsive force among them inside the nucleus.

    A quark inside a proton can be bound (by color) to the two other quarks in that proton, but it's also physically near the quarks of a neighboring proton. It can "look outside" it's own particle and see other nearby quarks, and feel the color force from those as well. That's what we call the strong force, and it keeps the nucleus together.

    If heavy nucleii were composed completely of protons, the aggregate electromagnetic repulsion would overwhelm the strong force and the nucleus would fly apart. Adding a few neutrons to the mix allows the same sort of neighboring-color-attraction without the EM repulsion, and makes the nucleus stable.

  20. Life of a proton by Anonymous Coward · · Score: 1

    "Wow, another day stuck in this darned nucleus, wondering if today will be the day we fall apart, not knowing what element I'll be part of next. Always worrying about whether the electrons out there really care about me or not. And what am I going to do if something takes an electron away from me--I mean us. I'll feel so empty. Yet there's this continuous pressure to perform, to keep it together. Keep hanging on, keep hanging on..."

  21. Quantized universe by Okian+Warrior · · Score: 1

    Or, by asking a question similar to yours, how do you calculate the pressure on an electron? Which dimensions would you choose to calculate the required area? Or do you consider that you cannot apply pressure on electrons? Or that electrons don't have area? Please, illustrate me.

    If the universe is computable (a strong requirement, since being "uncomputable" puts it outside of normal mathematics), then position must be quantized in some way. If position were a (mathematical) real number, then each position would require an infinite amount of information, and any interaction would be uncomputable.

    If position is quantized, then you can have a particle that occupies 1 quantum point and nothing else. It would be similar to having a computer game on a finite 3d grid of points - at the macroscopic scale everything would appear to be 3 dimensional, but when you get to the quantum level you could have particles that occupy one quantized point and no more. At that scale, for a particle occupying one quantized point, the concepts of surface area and volume lose their meaning.

    The universe is apparently quantized. Not in the simple way of the computer game mentioned above, but still quantized.

    So far as anyone can determine, an electron is a point particle. It has no volume and no surface area.

    1. Re:Quantized universe by CustomSolvers2 · · Score: 1

      then each position would require an infinite amount of information

      I am not saying otherwise. You can perfectly define the position of any body in space by relying on 3 dimensions, each of them defined by infinite numbers if you wish. But only 3 dimensions for all what we can see, touch, eat, etc.

      If position is quantized, then you can have a particle that occupies 1 quantum point and nothing else.

      You are mixing up theoretical approaches. If you want to rely on (Euclidean) geometry to perfectly position any element, you can do so. For the real world, you would need 3 dimensions and this is the beginning and the end of the story. If, for whatever reason, you prefer to rely on a different methodology, it would also be fine. But if you start mixing up ideas from both approaches and gluing them together by relying on so arbitrary means as treating different concepts as identical just for having the same name ("dimension"), then you might come to very wrong conclusions. And this is where your reasoning seems to be heading, but well... I will continue reading just in case.

      the concepts of surface area and volume lose their meaning.

      So far as anyone can determine, an electron is a point particle. It has no volume and no surface area.

      I don't like saying "I told you so", but... :)

      Let me go one step backwards and wonder about the exact point of our present discussion, of physics as a whole if you wish. The whole point here is getting a clear picture of an intrinsically complex reality. That's why we created abstractions like dimensions or pressure. Because of that same reason, some people rely on quantum mechanics to deal with certain scenarios. Within that context, you ideas might make sense, to help you/others understand better certain phenomena. It even makes lots of sense to have many rules, assumptions, re-definitions of concepts, etc. but only for as long as you are fulfilling the intended goal (properly understanding). When you forget about it and start blindly applying those originally-instrumental ideas everywhere else, even at the expense of reducing clarity, I stop seeing the point of your approach.

      --
      Custom Solvers 2.0 = Alvaro Carballo Garcia = varocarbas.
  22. Damn by DontBeAMoran · · Score: 1

    I always knew I was under constant pressure, but this is ridiculous.

    --
    #DeleteFacebook
  23. Re:Umm, what's doing the pushing? by Anonymous Coward · · Score: 1

    As expected, most of the replies are by people who don't know the subject matter, but want to pretend they are smart so they dismiss your question.

    It might be the strong and weak nuclear forces, or it might be the fundemental balancing of quark properties. It's also possible that the nuclear forces are side-effects of the fundamental quark balancing, or even the reverse.

    "Pressure" may not be a good term for it, but "required compressive energy per unit of predicted surface area of the current model for a sub-protonic component" doesn't fit the headlines well.

  24. Re: Then why did WTC7 collapse? by richy+freeway · · Score: 1

    I'm 40.

  25. Re: Then why did WTC7 collapse? by SlaveToTheGrind · · Score: 1

    I'm 40.

    So you were slightly ahead of your time. Congrats, I guess.

  26. Re: Then why did WTC7 collapse? by richy+freeway · · Score: 1

    *shrug*

    Had all the fucks I could give about it drained from me by the 9/11 truthers constantly repeating the same tired "facts" without bringing anything fresh or evidence based to the table.

    Even flat earthers annoy me less, at least they try!

  27. Now he's 10^^12 times too weak by Impy+the+Impiuos+Imp · · Score: 1

    > which is about 10 times greater than the pressure in the heart of a neutron star

    Superman should upgrade his Fortress of Solitude key to embarrass the Hulk even more.

    --
    (-1: Post disagrees with my already-settled worldview) is not a valid mod option.
  28. Quark stars? by Dasher42 · · Score: 1

    So, it's common for protons to resist pressure greatly higher than that found in a neutron star's core. Doesn't 10x greater than a neutron star's core - how big of a neutron star? - reach into the realm of gravity high enough to trap light? Doesn't this mean that some objects we perceive as black holes aren't singularities on the inside, but that the same force that keeps protons from collapsing into singularities will work for a star? Hence, they'd be quark stars *and* they'd appear like black holes from the outside?

  29. Re: Then why did WTC7 collapse? by St.Creed · · Score: 1

    Even flat earthers annoy me less, at least they try!

    That, they do! https://www.popularmechanics.c...

    --
    Therefore, by the (faulty) logic you're using, you're just a cow with a keyboard - osu-neko (2604)
  30. Feh. by Hallux-F-Sinister · · Score: 1

    Neutron stars are, it turns out, pussies. Every one of my protons says so.

    This begs the question though, what kind of pressure exists within a neutron, and is that pressure higher with the weight of a neutron star sitting on top of it?

    For all the bravado I've just exhibited over the relative pressure inside my protons compared to that within a neutron star, I probably would not want to get into a fight with one though.

    --
    Our reign has gone on long enough. Indeed. Summon the meteors.
  31. Re:Umm, what's doing the pushing? by belg4mit · · Score: 1

    I am indeed not a physicist, my point was simply that the OP's assertion that pressure is a bogus description is wrong. Pressure is not dependent on bouncing particles (cf. the cold bovine standing in for the typical elephant), and indeed is traditionally discussed in similar realms i.e; neutron stars.

    --
    Were that I say, pancakes?