Theoretical quark fusion found to be more powerful than hydrogen fusion

https://phys.org/news/2017-11-theoretical-quark-fusion-powerful-hydrogen.html

by daegloe • 9 years ago

65 44 9 years ago

iokevins• 9 years ago

The two main paragraphs:

"Prior work has suggested that energy is involved when quarks fuse together. In studying the properties of one such fusing, a doubly-charmed baryon, the researchers found that it took 130 MeV to force the quarks into such a particular configuration, but they also found that fusing the quarks together wound up releasing 12 MeV more than that. Intrigued by their finding, they quickly focused on bottom quarks, which are much heavier—calculations showed it took 230 MeV to fuse such quarks, but doing so resulted in a net release of approximately 138 MeV, which the team calculated was approximately eight times more than the amount released during hydrogen fusion.

Since hydrogen fusion lies at the heart of hydrogen bombs, the researchers were quite naturally alarmed at their findings. So much so that they considered not publishing their results. But subsequent calculations showed that it would be impossible to cause a chain reaction with quarks because they exist for too short a period of time—approximately one picosecond—not long enough to set off another baryon. They decay into much smaller, less dangerous lighter quarks."

nnfy• 9 years ago

Isn't it bad science to suppress findings? Where does one draw the line?

Suppression of results introduces subjectivity and allows for injection of agenda into what should be an objective practice. Not to mention, someone else will likely make the discovery eventually; would you rather suppress your findings and allow say, North Korea to be the first to develop a dangerous technology without any study into countermeasures?

Add this kind of bad practice to the other contemporary problems in research (replicability crisis, p value misuse, etc) and it feels like the modern scientific establishment is regressing.

SubiculumCode• 9 years ago

There are ideals and then are practicalities. Imagine a universe where it was discovered by theoretical modeling that speaking a certain word out loud would cause the earth to explode. Obviously scientists would want to know why or how such a weird phenomenon could exist under natural law, share and study it more. Practically speaking though, publishing it would be the end of life on earht, because one nincompoop of the X billion nincompoops in the world will go ahead and try it.

lucozade3• 9 years ago

Where does one draw the line?

Traditionally where there are clear military uses that one doesn't want to make available to an enemy.

would you rather suppress your findings and allow say, North Korea to be the first to develop a dangerous technology

They didn't say they wouldn't share it with anyone, they said they were thinking about not publishing it.

it feels like the modern scientific establishment is regressing

This isn't new by any means. For example, the development of fission had similar concerns and restrictions nearly a century ago.

colanderman• 9 years ago

Since hydrogen fusion lies at the heart of hydrogen bombs, the researchers were quite naturally alarmed at their findings. So much so that they considered not publishing their results. But subsequent calculations showed that it would be impossible to cause a chain reaction with quarks because they exist for too short a period of time—approximately one picosecond—not long enough to set off another baryon. They decay into much smaller, less dangerous lighter quarks.

I found this the most interesting part of the article. I wonder what, if any, groundbreaking research has been hidden by its discoverers due to its potential for misuse.

jogundas• 9 years ago

Probably not, as it would have been rapidly rediscovered. Particle physics is a large and active field of research.

klodolph• 9 years ago

This isn’t exactly the same thing, but differential cryptanalysis was known to IBM as early as 1974, and to the NSA even earlier. The techniques didn’t appear in published works until the late 1980s.

empath75• 9 years ago

I hope that people are keeping a lot of virus research under wraps, because at some point the ability to construct random genomes from scratch is going to get easy and inexpensive enough for terrorists to knock together.

otakucode2• 9 years ago

And you want to make sure that whatever the hypothetical terrorists whip up has never had any research done on its pathology, cure, or vaccine?

moomin• 9 years ago

"Those components, scientists have found, are called quarks."

Does anyone proof read anymore?

jerf2• 9 years ago

That may well be my favorite sentence I have read this year. It implies that scientists built particle accelerators and then these things popped out, and spoke to the scientists saying "Hi! We're called 'quarks'!" The first known self-naming particle.

I mean, this really solves all the questions about whether or not consciousness is an inherent property of the universe, if quarks themselves are already at a level that they can communicate their name to scientists. Profound stuff.

Let's, as they say, eat grandma: https://www.theguardian.com/media/mind-your-language/2014/se...

arethuza• 9 years ago

That reminds me of a description of "His Dark Materials" that a friend used to try and get me interested in the books "Imagine that dark matter is original sin"...

monochromatic• 9 years ago

It’s like something out of the British series “Look Around You.”

nategri• 9 years ago

Also the preceding sentences make it seem like quarks were discovered at the LHC (lol,no.)

yongjik2• 9 years ago

Since hydrogen fusion lies at the heart of hydrogen bombs, the researchers were quite naturally alarmed at their findings. So much so that they considered not publishing their results. But subsequent calculations showed that it would be impossible to cause a chain reaction with quarks because they exist for too short a period of time—approximately one picosecond—not long enough to set off another baryon. They decay into much smaller, less dangerous lighter quarks.

This must be either some kind of inside joke that was lost on the reporter, or a really poor reporting. You simply cannot accumulate stuff that decays in the order of picoseconds: if you can, you already have a bomb. No chain reaction needed.

After all, when they say "they decay into much smaller, less dangerous lighter quarks," it means they release all this dangerous energy.

It's like saying "Fortunately, this TNT decays into a much less dangerous mixture of inert nitrogen, water vapor, and carbon monoxide." Well, duh, it's exactly the process of decaying that makes TNT so dangerous.

goalieca• 9 years ago

Sure, but it’s the chain reaction that is needed to make the nuke.

AnimalMuppet2• 9 years ago

OK, but you have one picosecond to assemble your bomb. Let me know how much explosive power you manage to accumulate in that time. Also let me know how far away from your manufacturing facility you manage to move it before it goes off...

tantalor• 9 years ago

Perhaps a precursor reaction could be used to generate the necessary ingredients "just in time", like how a fission type of explosion is a precursor to a fusion explosion.

yongjik2• 9 years ago

Maybe I should have said "you have an explosion". I agree that this isn't really a bomb in the usual sense.

ckozlowski3• 9 years ago

If we were talking fission, then yes, you'd already have it. Once critical mass is achieved, then you have a reaction.

But for fusion, there is no critical mass as the ingredients (from a nuclear standpoint) are inert. So it's a matter of keeping them present and around long enough that it can be weaponized.

Early hydrogen bombs had this problem as they used cryogenic fuel. There was a real challenge of keeping the fuel from boiling off and having nothing to fuse.

Of course, that problem was solved. Not to suggest the challenge to keep a quark around for longer will prove to be as simple, but give it some decades...and things will be interesting.

otakucode2• 9 years ago

Hydrogen bombs are already of any desired variable strength. It would make no sense to pursue 'bigger' bombs. The hydrogen bombs we have now are already so large that no legitimate military target could ever exist which called for one. They're purely weapons of genocide with no reasonable military use. That's why Oppenheimer opposed their development in the 70s (and was burned for it).

dogma1138• 9 years ago

No if they decay into lighter quarks it doesn’t mean they release all that energy just the energy difference between the states.

Say you have 2 10meV particles that can fuse into a single 12meV particle this means that 8meV of energy has to be released in the process.

If they also have a decay route that say decays into a 9meV particle it means that only 2meV are released in the decay process.

If we take a real world example then hydrogen fusion releases about 14.5meV of excess energy on top of the helium atom when 2H and 3H fuse, deuterium (2H) is stable, tritium (3H) is not and it’s beta decay only releases 0.0018meV of energy.

This means that the energy released in a fusion reaction is about 8000 more than the beta decay of the tritium.

The product of the decay/fusion is also important the beta decay of tritium releases an electron and a neutrino the energy that goes into the neutrino is effectively sunk since it’s a weakly interactive particle which is basically harmless.

The electron is what you need to worry about in this case.

bovermyer• 9 years ago

Key phrase from this article:

At present, however, the very short lifetimes of the heavy bottom and charm quarks preclude any practical applications of such reactions.

In other words, this is just an academic exercise, albeit an interesting one.

jfindley• 9 years ago

I am definitely not a physicist by any means - as I understand it, the problem with hydrogen fission is not the amount of energy released but rather containing it and keeping it running stably for long periods of time, whilst using it to heat other things.

Is there anything to suggest that quark fusion would make any of these problems easier, or is this too early a stage for anyone to know that yet?

lucozade3• 9 years ago

the problem with hydrogen fission

It's actually fusion they're talking about here, not fission.

rather containing it ...

You're referring to using fusion as an energy source. Here they're just talking about the energy liberated in individual collisions not in sustainable reactions.

suggest that quark fusion would make any of these problems easier

The exact opposite. The article points out that there's no real chance of a chain reaction so you couldn't even produce a bomb never mind a sustainable energy source.

robinduckett• 9 years ago

So, if this could be scaled, could the energy be harvested? The way the article was worded sounded like they were getting more energy out than what they put in, even if it is fractional. What is involved in actually putting a reactor that worked on this principle to use practically? Would it require a much larger reactor than what is currently being developed?

programd• 9 years ago

The actual paper:

Quark-level analogue of nuclear fusion with doubly-heavy baryons

https://arxiv.org/abs/1708.02547

fallingfrog2• 9 years ago

Here's my question: We know that in the case of hydrogen fusion, the individual protons and neutrons involved change the way they are bound (two separate hydrogen atoms into a single helium), but they don't change into something else. But this is altogether different- we have individual quarks which are combining together to form a new kind of particle. Does that imply that quarks themselves are made of smaller particles?

I suppose there are other examples of this kind of fusion too- electron capture by a proton producing a neutron, for example.

bbojan2• 9 years ago

This is a great question! From my understanding, Quantum Field Theory posits that what we think of as particles are actually excitations of the underlying fields.

So when a neutron decays into a proton and an electron, it doesn't mean that the neutron consists of a proton and an electron; merely that the "neutron field" has a coupling with a "proton field" and an "electron field".

So particles can indeed turn into other particles, as long as certain conservation laws are obeyed.

[Edit: typo]

xelxebar• 9 years ago

Wait, can you approximate protons and neurons as excitations in proton and neutron fields instead of as specific valences of a quark-gluon plasma?

noobermin• 9 years ago

Not really. The standard model has them as fundamental particles, I think you might be reading too much into the analogy.

Also, they aren't individual quarks "combining" into something else, it is an interaction between baryons which are groups of quarks and the "output" has an exchange of quarks between the baryons. Quarks can't be "free" at most energy scales due to color confinement.

fallingfrog2• 9 years ago

Oh ok, got it. That makes sense. I think it was the phrasing in the paper such as "..fusing quarks can release much more energy than anyone thought.." "..energy is involved when quarks fuse together.." and so on that got me. I didn't catch that it's baryons being fused not quarks.

hirundo• 9 years ago

Alternate title: Theoretical solution of the Fermi Paradox

Theoretical quark fusion found to be more powerful than hydrogen fusion

Related Stories