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New exotic matter particle, a tetraquark, discovered at CERN

phys.org

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Re: New exotic matter particle, a tetraquark, discovered at CERN

#151

Post by im3w1l »

whatshisface wrote: post #11
danslo wrote: post #3

>Such proximity in mass makes the decay "difficult," resulting in a longer lifetime of the particle, and indeed Tcc+, is the longest-lived exotic hadron found to date. So... how long does it live?

The resonance width is inversely proportional to the lifetime, and if the resonance width is about 400keV, the particle would live for about 10^-21 seconds. For comparison, neutrons decay via the weak force in about 800 seconds, and delta baryons, a randomly chosen strong force decay, live for 10^-24 seconds. That makes this tetraquark long-lived for a strong decay, but that's way, way faster than a weak decay. https…

Despite free neutrons decaying in 800s, there are many stable elements containing neutrons. Would it be possible to imagine a tetraquark as an ingredient of a stable particle?

Re: New exotic matter particle, a tetraquark, discovered at CERN

#152

Post by BrissyCoder »

AlexCoventry wrote: post #111
f6v wrote: post #54

Earlier quoted context omitted.

It’s a great book, but it suffers from the same old issue. A civilization that is capable of packing a robot into particle by manipulating higher dimensions doesn’t need to take our planet. They could terraform Mars or any other planet they want.

There's also the weird aspect that [rot13'd for spoilers] gur fbcubagf frrz gb or noyr gb vasyhrapr naq dhrel znggre, ohg pna'g frrz gb ernq crbcyr'f zvaqf be xvyy gurz.

TIL google translate doesn't do ROT13.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#153

Post by Dylan16807 »

seanc wrote: post #141
ansible wrote: post #121

Earlier quoted context omitted.

> True for what it is, but this is handled in the books. They literally don’t want our planet, they want our star. That's... an odd reason. There are plenty of stars out there, unless the aliens started out right next door (like in Alpha Centauri) there's not much reason to go after our star. I haven't read the books...

Well, the thesis is that with exponential growth and a modest amount of time there _aren't_ plenty of stars out there.

If you're growing that fast, then a system or two is a rounding error. You won't have plenty no matter what you do, so how about not wiping out other species for that extra smidge?

Re: New exotic matter particle, a tetraquark, discovered at CERN

#154

Post by Gravityloss »

hnuser123456 wrote: post #113
adrianN wrote: post #38

Earlier quoted context omitted.

I like black holes because once you have one you don't need an accelerator for refueling. https://arxiv.org/abs/0908.1803

Huh, "black holes move when you push them" is interesting. I suppose you could feed it with a beam, but focusing a beam down to attometer-size beamwidth seems like the hardest part, ignoring making a subatomic black hole in the first place. But sure, I suppose capturing the radiation and redirecting most of it back into the black hole to push it and maintain its size, and just enough spare to push the ship itself at…

Power scales to the square of exhaust velocity while thrust linearly, so if you have a very good power to weight power source like a black hole, you can use a very high exhaust velocity and thus can get by with very little reaction mass. Which is good.

Also, you can make a spaceship out of an asteroid (or from asteroid materials) so multi WTC mass is not a problem.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#156

Post by AmericanChopper »

roywiggins wrote: post #126
SkyMarshal wrote: post #109

Earlier quoted context omitted.

They could send the subatomic particles from Trisolaris to Earth at light speed, and then use the entangled pair of particles (one on earth, its mate on Trisolaris) to monitor events on earth in real-time. As already said, that preserves the planet, prevents a potential enemy from further developing technologically, and enables real-time monitoring of and interference with that enemy's activities.

>and then use the entangled pair of particles (one on earth, its mate on Trisolaris) to monitor events on earth in real-time. This, of course, breaks the known laws of physics, since lightspeed is a hard limit on the speed of causality. You can't use entanglement that way in the real world (if QM is anywhere close to correct)

The sophons themselves were a piece of magic science fiction. Which I think is fine because the author really doesn’t ask you to suspend your disbelief all that much throughout the books. The star plucking is another example, as far as we know you can’t use a star to do that.

But accelerating them towards earth “at the speed of light” isn’t exactly a problem. The LHC accelerates protons to about 3 m/s less than the speed of light, and as far as the plot is concerned the sophons travelling here at the speed of light, or some tiny fraction of a percent less than the speed of light doesn’t make any difference.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#157

Post by AmericanChopper »

cogman10 wrote: post #95
ASalazarMX wrote: post #83

Earlier quoted context omitted.

Super spoiler below: Their tri-solar system was too unstable to terraform, they needed a stable solar system to migrate to. Of course ours was the nearest with an habitable planet (otherwise there wouldn't be much of a story), so they can immediately colonize Earth, and probably begin the centuries-long process of terraforming the neighboring planets.

Still doesn't make sense. Why limit our tech when they ultimately want to just eliminate us all together? Drop a super virus on us or irradiate the whole planet. Any species capable of disrupting our particle accelerators is more than capable of wiping us from existence.

They did also send weapons towards earth ahead of their fleet. They arrived much faster than their fleet, but much slower than the sophons.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#158

Post by jjoske »

Panoramix wrote: post #136
f6v wrote: post #54

Earlier quoted context omitted.

It’s a great book, but it suffers from the same old issue. A civilization that is capable of packing a robot into particle by manipulating higher dimensions doesn’t need to take our planet. They could terraform Mars or any other planet they want.

Spoilers ahead It was such a letdown, the book starts great, and then the explanation turns out to be magical Alien proton computers? Yikes. It was so promising. I eventually read the whole trilogy, I have very mixed feelings about it. It had some pretty cool ideas but it's hard to get past all the giant plot holes and outlandish fantasy. I guess you have to be in the mood to constantly brush off the bad parts (and b…

There where some good ideas in it but it never really worked for me, I have often wondered if it was translation issues.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#159

Post by cmurf »

f6v wrote: post #54
pseudobry wrote: post #42

I recently finished The Three-Body Problem and The Dark Forest, which explore the concept of aliens using their super advanced technology to mess with the results of Earth's particle accelerators, thereby stopping humanity's ability to develop technology based on new physics. Is this discovery exciting? Or are we living in The Three-Body Problem?

It’s a great book, but it suffers from the same old issue. A civilization that is capable of packing a robot into particle by manipulating higher dimensions doesn’t need to take our planet. They could terraform Mars or any other planet they want.

Human story tellers are very attached to humanity, so the stories tend to anthropomorphize aliens. Most alien stories rehash old religious and hero stories. What do we have to offer aliens? In the category of vague as well as less is more, Arrival/Stories of Your Life and Others are about as compelling as it gets - humanity hasn't yet achieved full potential, going further out on a limb is folly (however entertaining it might be, it becomes less compelling).

The more truly alien, the less in common we have in all respects, the more boring that story turns out to be because? We're a selfish, self-interested, loathsome species who consistently overestimates its importance. The more different a fellow human is, the vast majority of people reject that individual because of their (weird) non-social behaviors.

So these alien stories strike me as deification, angels, devils, i.e. the supernatural, and don't adequately explain why or how any alien civilization would take interest in us, except via our own attachments to ourselves. This is central to good science fiction because they are stories ultimately about exploring something about humanity, it's not really about aliens at all. They're entirely incidental even if they seem important, aliens are just a literary device. But getting to science-non-fiction, a factual case of aliens, that's quite hard for most humans to imagine at all.

Consider how poorly most people coped with covid, and then consider how much more traumatic an alien visit would be, even assuming they were nice.

In Arthur C. Clarke's Childhood's End (1953) those aliens were "nice" but with a really big caveat. (And neatly explained devils.) But again, humans are the central part of that story, not aliens. It wouldn't and couldn't have been interesting to focus on the interests of the aliens without us being part of the story - we're just too self-interested by nature. The aliens' interests would have been boring to us, we just don't have the necessary common frame of reference with such beings. How could we?

Re: New exotic matter particle, a tetraquark, discovered at CERN

#160

Post by bmh100 »

wdwvt1 wrote: post #112
gizmo686 wrote: post #103

Earlier quoted context omitted.

More spoilers below: They actualy did a fair amount of geopolitical manipulations. That formed most of the plot. In the end, it turned out to be MAD that saved us, but setting up the MAD scenario involved secrecy from them (or else they would have stopped us before we could trigger it), and from the rest of humanity (because an official plan to destroy Earth would never have been approved).

It seems like the manipulations were exceedingly silly. It seems like having the sophont start a nuclear war would be straightforward. It was hard for me to suspend disbelief in the sense that it had planet-sized computational power and the ability to manipulate some information on the subatomic level, but couldn't find a vulnerability in aging nuclear launch protocols? The history of near misses with human controlle…

The aliens specifically wanted Earth because of its life. A nuclear war would damage the planet's ecosystem too much.
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