New exotic matter particle, a tetraquark, discovered at CERN • Hacker News Board

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

#211

Post by ThinkBeat » Sat, Jul 31, 2021, 4:42 PM UTC

abainbridge wrote: post #197

brianpan wrote: post #183

Earlier quoted context omitted.

"We now think that" is the qualifier on the entirety of physics. It's redundant.

Haha. True. Some parts of physics are way shakier than others though. For example, the whole big bang, dark matter, dark energy area needs the qualifier of, "We know we've got something wrong here, but its the best we've got". (eg see https://en.wikipedia.org/wiki/Big_Bang#Problems_and_related_... ). I'm trying not to be controversial here. I'm just using this as an example of physics with well known problems. Regard…

There is a theory about Preons.

This theory has fallen out of fashion.

"In particle physics, preons are point particles, conceived of as sub-components of quarks and leptons."

https://en.wikipedia.org/wiki/Preon

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

#212

Post by complexmango » Sat, Jul 31, 2021, 6:06 PM UTC

brianpan wrote: post #183

ThinkBeat wrote: post #182

"Quarks are the fundamental building blocks from which matter is constructed." I sometimes wish would include "In our current model", "We now think that", or some other qualifier. Such absolute statements have been made frequently prior to our current understanding. I have no special knowledge to lead me to believe that quarks are not the end all of parties. But I was happy with atom being the fundamental thing, and…

"We now think that" is the qualifier on the entirety of physics. It's redundant.

If only epidemiologists had such humility

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

#213

Post by clarkb286 » Sat, Jul 31, 2021, 9:04 PM UTC

wiseStab wrote: post #184

tw04 wrote: post #172

Earlier quoted context omitted.

There's a very big difference between calling something clickbait and saying "everything from the media is a lie".

"every news headlines are inaccurate" is a good rule of thumb though.

"Every comment which contains multiple grammar errors loses all credibility and is therefore invalid." is undeniable, though.

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

#214

Post by danielheath » Sat, Jul 31, 2021, 11:21 PM UTC

bo0tzz wrote: post #194

danielheath wrote: post #143

Earlier quoted context omitted.

The same way you use a private key in a computer without transmitting it?

So how are you intending to do those calculations in your mind?

By being a super-advanced space alien?

I mean, or just practicing. Humans who put in the time can do pretty amazing stuff.

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

#215

Post by brianpan » Sun, Aug 01, 2021, 5:44 AM UTC

abainbridge wrote: post #197

brianpan wrote: post #183

Earlier quoted context omitted.

"We now think that" is the qualifier on the entirety of physics. It's redundant.

Haha. True. Some parts of physics are way shakier than others though. For example, the whole big bang, dark matter, dark energy area needs the qualifier of, "We know we've got something wrong here, but its the best we've got". (eg see https://en.wikipedia.org/wiki/Big_Bang#Problems_and_related_... ). I'm trying not to be controversial here. I'm just using this as an example of physics with well known problems. Regard…

It's much worse than you think.

In physics there is 1) we know this is definitely wrong but it's useful and 2) this is very right so far and it's probably going to be wrong. I'm only a little bit joking. Now, I am not a physicist but I have been in a physics rabbit hole for a few months now.

The absolute best most experimentally verified theories we have are: general relativity and quantum mechanics. These are the pinnacle of physics. And they are incompatible with each other. So we know for sure that one is wrong. Or both are wrong.

String theory might be the resolution of that, making strings the most fundamental thing. But we've been working on it for 50 years with basically nothing to show for it so far. And there may be more beyond strings, who knows.

Of course there are many things in physics we can say with great confidence. But in terms of fundamental understanding there is ONLY "we now think that".

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

#216

Post by evanb » Sun, Aug 01, 2021, 8:20 AM UTC

dukwon wrote: post #203

im3w1l wrote: post #151

Earlier quoted context omitted.

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?

No. The presence of a valence antiquark guarantees it will decay at some point.

That’s not the full explanation; the antiproton is stable (or, is as stable as the proton).

It’s that the net baryon number is 0 and that the flavor ‘quantum numbers’ aren’t conserved by the weak force. If you could turn off the weak force, this cc ubar dbar tetraquark would be absolutely stable.

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

#217

Post by alasdair_ » Mon, Aug 02, 2021, 5:44 PM UTC

bo0tzz wrote: post #194

danielheath wrote: post #143

Earlier quoted context omitted.

The same way you use a private key in a computer without transmitting it?

So how are you intending to do those calculations in your mind?

There is a section in the novel Cryptonomicon where the protagonist is in a jail cell and monitored 24/7. He communicates with another person via a deck of cards, with all of the cryptography performed in the two people's minds. It's annoying to do but should certainly be possible if the fate of the world is at stake.