
Theoretical quark fusion found to be more powerful than hydrogen fusion - daegloe
https://phys.org/news/2017-11-theoretical-quark-fusion-powerful-hydrogen.html
======
yongjik
> 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.

~~~
AnimalMuppet
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
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.

~~~
AnimalMuppet
That's not a bad idea, but I still don't think it would work. There are at
least two problems.

First is the _rate_ at which you can generate the precursors. How many can you
generate in a picosecond? That's how big your explosion can be. Or rather, the
explosion will be as big as how many you can generate in a picosecond, times
however many picoseconds you can sustain generating them (plus the force
needed to make the fusion reaction happen).

The second problem is that generating the ingredients probably takes at least
as much energy as you get out of the fusion reaction. At that point, whatever
you're using to generate the energy can be your weapon, without needing the
intermediate step of the quark fusion reaction. (As the Schlock Mercenary web
comic says, "Any sufficiently advanced technology is indistinguishable from a
really big gun.")

------
moomin
> "Those components, scientists have found, are called quarks."

Does anyone proof read anymore?

~~~
jerf
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...](https://www.theguardian.com/media/mind-your-
language/2014/sep/04/mind-your-language-commas)

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

~~~
IanCal
Perfect comparison.

For anyone that's not seen Look Around You, all the episodes are on youtube.
Season 1 is the one to start with, there's two seasons and they're very
different.

Some of this won't translate as well, the episodes are absurdist versions of
shows that used to be on BBC2 very early in the morning. There would be a show
as some science lesson, put on at 2am for people to tape and show in classes.
I'm sure it's a pretty wide age range but I'm 30 and seeing slightly warped
tapes playing this kind of thing was pretty common for me. Still, even without
this I think they're pretty fun.

There's also the pilot for calcium on youtube but there's the other episodes
here:

[https://www.youtube.com/user/LookAroundYouDVD](https://www.youtube.com/user/LookAroundYouDVD)

~~~
darrenf
The shows to which you refer were not necessarily to be shown in classes -
AIUI they _were_ the classes/lectures for the Open University, a distance
learning uni which still exists to this day. The broadcasts lasted into the
mid-00s:
[http://news.bbc.co.uk/1/hi/education/6182747.stm](http://news.bbc.co.uk/1/hi/education/6182747.stm)

~~~
IanCal
Ah thanks, my viewing of them was limited entirely to secondary school lessons
so I assumed a lot were intended with this audience in mind, sort of a
forerunner to bitesize.

------
iokevins
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
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.

~~~
lucozade
> 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.

~~~
oxide
This is about fusion, not fission. Your point stands of course!

since they are technically inverse its important to clarify IMO.

~~~
lucozade
Poor wording on my part. I've made it a little clearer. Thanks

------
colanderman
> 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.

~~~
empath75
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.

~~~
otakucode
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?

------
fallingfrog
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.

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

~~~
bbojan
I have no idea. That's why I put it in quotes :-)

------
programd
The actual paper:

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

[https://arxiv.org/abs/1708.02547](https://arxiv.org/abs/1708.02547)

------
bovermyer
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.

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jfindley
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?

~~~
lucozade
> 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.

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robinduckett
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?

------
hirundo
Alternate title: Theoretical solution of the Fermi Paradox

