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Is particle physics dead, dying, or just hard?

quantamagazine.org

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Re: Is particle physics dead, dying, or just hard?

#121

Post by plomme »

ggm wrote: post #46

I am sure others will say it better, but the cat-in-the-box experiment is a shockingly bad metaphor for the idea behind quantum states and observer effect. I will commit the first sin, by declaring without fear of contradiction the cat actually IS either alive or dead. it is not in a superposition of states. What is unknown is our knowledge of the state, and what collapses is that uncertainty. If you shift this to th…

Well you are in luck because that was the point of Schroedingers cat; it was constructed to show the impossibly odd implications of quantum mechanics.

From the wikipedia page: “This thought experiment was devised by physicist Erwin Schrödinger in 1935 in a discussion with Albert Einstein to illustrate what Schrödinger saw as the problems of Niels Bohr and Werner Heisenberg's philosophical views on quantum mechanics.”

Re: Is particle physics dead, dying, or just hard?

#123

Post by WantonQuantum »

tariky wrote: post #115

To my uneducated eye it looks like they are stuck in limbo for 120 years. Nothing practical has been create based on those theories. It is just words and calculations spinning in circles. I wish those people focus on practical real world physics. So we all can enjoy new innovations.

The device you used to make this comment relies heavily on quantum effects to make efficient transistors. The necessary theoretical understanding of semiconductors did not exist 120 years ago.

Re: Is particle physics dead, dying, or just hard?

#124

Post by jacquesm »

galaxyLogic wrote: post #112
Paracompact wrote: post #57

Earlier quoted context omitted.

Personally—and this is where I expect to lose the materialists that I imagine predominate HN—I think we are already in a nightmare scenario with regard to another area: the science of consciousness. The following seem likely to me: (1) Consciousness exists, and is not an illusion that doesn't need explaining (a la Daniel Dennett), nor does it drop out of some magical part of physical theory we've somehow overlooked u…

I don't think there is any mystery to what we call "consciousness". Our senses and brain have evolved so we can "sense" the external world, so we can live in it and react to it. So why couldn''t we also sense what is happening inside our brains? Our brain needs to sense our "inner talk" so we can let it guide our decision-making and actions. If we couldn't remember sentences, we couldn't remember "facts" and would be…

This is not nearly as profound as you make it out to be: a computer program also doesn't sense the hardware that it runs on, from its point of view it is invisible until it is made explicit: peripherals.

Re: Is particle physics dead, dying, or just hard?

#125

Post by joe_the_user »

Paracompact wrote: post #23
bananaflag wrote: post #7

It's basically the opposite situation from 150 years ago. Back then, we thought our theory was more or less complete while having experimental data which disproved it (Michelson-Morley experiment, Mercury perihelion, I am sure there are others). Right now, we know our theories are incomplete (since GR and QFT are incompatible) while having no experimental data which contradicts them.

What about underexplained cosmological epicycles like dark matter (in explaining long-standing divergences of gravitational theory from observation), or the Hubble tension?

The dark matter theory broadly is that there is amount of invisible matter that obeys the laws of Einsteinian gravity but isn't otherwise visible. By itself, it has considerable experimental evidence. It doesn't resemble Ptolemaic theories of planetary motion notably in that doesn't and hasn't required regular updating as new data arrives.

It really fits well with the OP comments. Nothing really contradicts the theory but there's no deeper theory beyond it. Another comment mentioned as "nightmare" of dark matter only have gravitational interaction with other matter. That would be very unsatisfying for physicists but wouldn't something that really disprove any given theory.

Re: Is particle physics dead, dying, or just hard?

#126

Post by WantonQuantum »

albatross79 wrote: post #97

Why are we even trying to look deeper? To fit our mathematical curves better? Abstract spacetime, fields, virtual particles, wave function collapse, quantized energy, wave particle duality, etc. This is all BS. And I'm not disputing the theories or the experimental results. These concepts are unintelligible. They are self contradictory. They are not even abstractions, they are mutually exclusive paradigms forced toge…

I find quite a lot of it very satisfying. For example, the deep mathematical symmetries of gauge theory and how they relate to the observed forces of the universe is truly amazing.

The excellent Arvin Ash has a very accessible video about it: https://www.youtube.com/watch?v=paQLJKtiAEE

Re: Is particle physics dead, dying, or just hard?

#127

Post by bsder »

beezle wrote: post #72
bsder wrote: post #10

Theoretical physics progresses via the anomalies it can't explain. The problem is that we've mostly explained everything we have easy access to. We simply don't have that many anomalies left. Theoretical physicists were both happy and disappointed that the LHC simply verified everything--theories were correct, but there weren't really any pointers to where to go next. Quantum gravity seems to be the big one, but that…

Please do not conflate the broad "theoretical physics" with the very specific "beyond the standard model" physics questions. There are many other areas of physics with countless unsolved problems/mysteries.

Sure, there are things like "Really, how do superconductors work?", but nobody (mostly) believes that understanding things like that requires "new physics".

And, I think, most people would place that kind of stuff under "solid state physics" anyway.

Re: Is particle physics dead, dying, or just hard?

#128

Post by jacquesm »

tasty_freeze wrote: post #48
Paracompact wrote: post #21

Earlier quoted context omitted.

Technically, the charge of a proton can be derived from its constituent 2 up quarks and 1 down quark, which have charges 2/3 and -1/3 respectively. I'm not aware of any deeper reason why these should be simple fractional ratios of the charge of the electron, however, I'm not sure there needs to be one. If you believe the stack of turtles ends somewhere, you have to accept there will eventually be (hopefully simple) c…

I'm aware of the charge coming from quarks, but my point remains. > you have to accept there will eventually be (hopefully simple) coincidences between certain fundamental values, no? When the probability of coincidence is epsilon, then, no. Right now they are the same to 12 digits, but that undersells it, because that is just the trailing digits. There is nothing which says the leading digits must be the same, eg, o…

I think I agree with you. It could be just a matter of static bias or some other fairly simple mechanism to explain why these numbers are the same.

Imagine an object made of only red marbles as the 'base state'. Now you somehow manage to remove one red marble: you're at -1. You add a red marble and you're at +1. It doesn't require any other marbles. Then you go and measure the charge of a marble and you and up at some 12 digit number. The one state will show negative that 12 digit number the other will show positive that 12 digit number.

Assigning charge as being the property of a proton or an electron rather than one of their equivalent constituent components is probably a mistake.

Re: Is particle physics dead, dying, or just hard?

#129

Post by lefra »

ggm wrote: post #76
sliken wrote: post #73

Earlier quoted context omitted.

Along similar lines, the double-slit experiment, seems simple. Two slits let light though and you get bands where they constructively or destructively interfere, just like waves. However I still find it crazy that when you slow down the laser and one photon at a time goes through either slit you still get the bands. Which begs the question, what exactly is it constructively or destructively interfering with? Still se…

I had a conversation about this in HN some months back. It's a surprisingly modern experiment. It demanded an ability to reliably emit single photons. Young's theory may be 1800 but single photon emission is 1970-80. (This is what I was told, exploring my belief it's always been fringes in streams of photons not emerging over repeated applications of single photons and I was wrong)

To get single photons, you just need to stack up enough stained glass infront of a light source. That's been acheivable for aeons (the photon will go through at random time though).

The difficult part is single photon _detectors_, they're the key technology to explore the single-photon version of Young's experiment (which originally showed that light has wave-like properties).

Re: Is particle physics dead, dying, or just hard?

#130

Post by threethirtytwo »

tehjoker wrote: post #120
threethirtytwo wrote: post #106

Earlier quoted context omitted.

I don't understand what is wrong with pessimism. That's not a valid critique. If someone is pessimistic but his description of the world matches REALITY, then there's nothing wrong with his view point. Either way this is also opinion based. There hasn't been a revolutionary change in technology in the last 20 years. I don't consider smart phones to be revolutionary. I consider going to the moon revolutionary and catc…

genetic technology and computing technology have been the biggest drivers for a while. i do think it is remarkable to video call another continent. communication technology is disruptive and revolutionary though it looks like chaos. ai is interesting too if it lives up to the hype even slightly. catching a rocket is very impressive, but its just a lower cost method for earth orbit. it does unlock megaconstellations t…

Yeah none of those are step function changes. Video calling another continent is like a tiny step from TV. Yeah I receive video wirelessly on my tv not that amazed when I can stretch the distance further with a call that has video. Big deal.

AI is the step function change. The irony is that it became so pervasive and intertwined with slop people like you forget that what it does now (write all code) was unheard of just a couple years ago. ai surpassed the hype, now it’s popular to talk shit about it.

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