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Well, maybe it isn’t worth spending another 20B on a new particle accelerator, but if so how should we continue? Smashing particles together at high energies is

Well, maybe it isn’t worth spending another 20B on a new particle accelerator, but if so how should we continue? Smashing particles together at high energies is at least a proven strategy that has yielded results in the past and I personally don’t know how we would do high energy physics without them? Maybe we could think of finding ways to investigate naturally occurring particles at those high energies (e.g. via cosmic radiation) but that seems more sci-fi than reality and also won’t cost less than 20B I would argue. Also, not making progress for 40 years is not really long, we just tend to view everything relative to our own lifespan and we were also pretty spoiled with the marvelous discoveries we made in the last 100 years, but it’s entirely possible that we have now worked out all the “easy” stuff and that making further progress will take 1000s of years (though I think that’s unlikely).

sandworm101 8y ago
Let the universe provide the high energy particles. Biuld big detectors, not accelerators. And telescopes to study objects like quazars that too are just sitting there demoing high energy physics 24/7.
- ThePhysicist 8y ago
  Sure I think we’re already doing that, but I also think this makes it very difficult to observe results let alone make controlled experiments. I can’t recall any particle or fundamental force that was validated / found in this way, the only thing I can think of are tests of the theory of general relativity that use astronomical observations, but I don’t recall anything in the field of particle physics (it’s not my field though so I might just have missed it).
  - sandworm101 8y ago
    The hunt for dark matter, for whatever particle/string/widget is involved, is a particle physics problem. String theory may find support, or not, through the observation of black holes (ie fuzzball). Neutrino detectors made big contributions in thier day.
  - enriquto 8y ago
    Going much further in the past, you have the discovery of the element helium, whose existence was predicted by the periodic table, and it was detected first in the sun atmosphere (looking at the spectrum of sunlight during an eclipse) than on earth (where it is very abundant, but mixed with natural gas).
  - peteradio 8y ago
    > I can’t recall any particle or fundamental force that was validated / found in this way LIGO? Gravity waves?
    - ThePhysicist 8y ago
      That’s what I meant with tests of general relativity. Ligo didn’t prove the existence of gravitons though.
  - raverbashing 8y ago
    Before particle accelerators, we had physicists climbing mountains and pointing photographic film at the skies
  - eigenhombre 8y ago
    Counterexample: discovery of the positron in cosmic radiation https://en.wikipedia.org/wiki/Positron#Natural_production https://en.wikipedia.org/wiki/Positron#Natural_production
- smueller1234 8y ago
  3000km^2 in Argentina: the Pierre Auger Observatory (http://auger.org http://auger.org) for ultra high energy cosmic rays. It was meant to get a follow-up 7x the size in Colorado but it was defunded by NSF as a result of the 2008 crisis. The exciting prospect of this was that at extremely high energies of cosmic rays (where they get very sparse: 1/km^2/century), these charged particles have a relatively short range (in astronomical terms - they're not from our galaxy; look up the GZK effect). That meant that they wouldn't be deflected by magnetic fields as much and could - thus the intent - be traced back to their sources. The clou: we have no credible theory for any process that would put this much energy into a single particle, so knowing their sources would be a step towards solving a physics mystery. Source: worked on my PhD there.
  - smueller1234 8y ago
    PS: Pertinent to this thread. The Pierre Auger Observatory cost around 40M$.
coldtea 8y ago
>Smashing particles together at high energies is at least a proven strategy that has yielded results in the past and I personally don’t know how we would do high energy physics without them? Isn't that a little cyclical? Why should we do "high energy physics" as opposed to just physics? Aren't there other ways to come at fundamental particles than smashing things together and seeing what happens? >Also, not making progress for 40 years is not really long Compared to the previous 100 years rate of progress, which was the baseline, it is huge.
- ThePhysicist 8y ago
  That’s what I said, making tremendous progress in the last 100 years doesn’t mean we will continue making progress at the same rate (though I hope it’ll be the case or that we actually accelerate our rate of disclvery). There are good ways to learn about fundamental physics apart from particle accelerators, but for investigating the structure of matter in a systematic and reproducible way there aren’t many alternatives as far as I know.
- philwelch 8y ago
  > Compared to the previous 100 years rate of progress, which was the baseline, it is huge. That's kind of cherry-picking, isn't it? 1850-1950 basically rewrote the sum of human knowledge when it comes to physics. That isn't a "baseline", it's a major breakthrough.
  - coldtea 8y ago
    >That's kind of cherry-picking, isn't it? 1850-1950 basically rewrote the sum of human knowledge when it comes to physics. That isn't a "baseline", it's a major breakthrough. And we're at the end of the sigmoid curve of that breakthrough...
    - philwelch 8y ago
      Exactly. So maybe it makes sense to reallocate some resources to concrete applications of what we already know, but it still isn't fair to expect basic research to make the same kind of progress today that it made in the 1900's (the decade, not the century).

sandworm101 8y ago

Let the universe provide the high energy particles. Biuld big detectors, not accelerators. And telescopes to study objects like quazars that too are just sitting there demoing high energy physics 24/7.

ThePhysicist 8y ago
Sure I think we’re already doing that, but I also think this makes it very difficult to observe results let alone make controlled experiments. I can’t recall any particle or fundamental force that was validated / found in this way, the only thing I can think of are tests of the theory of general relativity that use astronomical observations, but I don’t recall anything in the field of particle physics (it’s not my field though so I might just have missed it).
- sandworm101 8y ago
  The hunt for dark matter, for whatever particle/string/widget is involved, is a particle physics problem. String theory may find support, or not, through the observation of black holes (ie fuzzball). Neutrino detectors made big contributions in thier day.
- enriquto 8y ago
  Going much further in the past, you have the discovery of the element helium, whose existence was predicted by the periodic table, and it was detected first in the sun atmosphere (looking at the spectrum of sunlight during an eclipse) than on earth (where it is very abundant, but mixed with natural gas).
- peteradio 8y ago
  > I can’t recall any particle or fundamental force that was validated / found in this way LIGO? Gravity waves?
  - ThePhysicist 8y ago
    That’s what I meant with tests of general relativity. Ligo didn’t prove the existence of gravitons though.
- raverbashing 8y ago
  Before particle accelerators, we had physicists climbing mountains and pointing photographic film at the skies
- eigenhombre 8y ago
  Counterexample: discovery of the positron in cosmic radiation https://en.wikipedia.org/wiki/Positron#Natural_production https://en.wikipedia.org/wiki/Positron#Natural_production
smueller1234 8y ago
3000km^2 in Argentina: the Pierre Auger Observatory (http://auger.org http://auger.org) for ultra high energy cosmic rays. It was meant to get a follow-up 7x the size in Colorado but it was defunded by NSF as a result of the 2008 crisis. The exciting prospect of this was that at extremely high energies of cosmic rays (where they get very sparse: 1/km^2/century), these charged particles have a relatively short range (in astronomical terms - they're not from our galaxy; look up the GZK effect). That meant that they wouldn't be deflected by magnetic fields as much and could - thus the intent - be traced back to their sources. The clou: we have no credible theory for any process that would put this much energy into a single particle, so knowing their sources would be a step towards solving a physics mystery. Source: worked on my PhD there.
- smueller1234 8y ago
  PS: Pertinent to this thread. The Pierre Auger Observatory cost around 40M$.

coldtea 8y ago

>Smashing particles together at high energies is at least a proven strategy that has yielded results in the past and I personally don’t know how we would do high energy physics without them? Isn't that a little cyclical? Why should we do "high energy physics" as opposed to just physics? Aren't there other ways to come at fundamental particles than smashing things together and seeing what happens? >Also, not making progress for 40 years is not really long Compared to the previous 100 years rate of progress, which was the baseline, it is huge.

ThePhysicist 8y ago
That’s what I said, making tremendous progress in the last 100 years doesn’t mean we will continue making progress at the same rate (though I hope it’ll be the case or that we actually accelerate our rate of disclvery). There are good ways to learn about fundamental physics apart from particle accelerators, but for investigating the structure of matter in a systematic and reproducible way there aren’t many alternatives as far as I know.
philwelch 8y ago
> Compared to the previous 100 years rate of progress, which was the baseline, it is huge. That's kind of cherry-picking, isn't it? 1850-1950 basically rewrote the sum of human knowledge when it comes to physics. That isn't a "baseline", it's a major breakthrough.
- coldtea 8y ago
  >That's kind of cherry-picking, isn't it? 1850-1950 basically rewrote the sum of human knowledge when it comes to physics. That isn't a "baseline", it's a major breakthrough. And we're at the end of the sigmoid curve of that breakthrough...
  - philwelch 8y ago
    Exactly. So maybe it makes sense to reallocate some resources to concrete applications of what we already know, but it still isn't fair to expect basic research to make the same kind of progress today that it made in the 1900's (the decade, not the century).