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Sure, but these days it's where discoveries are made. You know, in some sense experimental physics used to be "ahead" of theoretical physics. I accidentally pu

Sure, but these days it's where discoveries are made. You know, in some sense experimental physics used to be "ahead" of theoretical physics. I accidentally put some current next to a compass and it moves. Why, no one knows. I would say from 1905 onwards theoretical physics has been ahead of experimental physics. I have reasons to believe X, and a few years later experimentalists verify it. This difference is getting larger very fast. It took from 1933 when neutrinos were postulated by Fermi to being discovered in 1956. It took about 40 years from Higgs suspecting an extra particle was needed to it being found in experiments.

pvg 9y ago
Maybe that's cheating a little but astronomy and astrophysics have had a good run of observations which physical cosmology then chases. Most of them after 1905.
danharaj 9y ago
High energy physics isn't the only physics. It's not even the only physics that uses the shiniest toys of theoretical physics.
- hpcjoe 9y ago
  Heh ... in grad school, one of my friends was a postdoc working on computing bounds for the Higgs mass. He used to tell me (theoretical condensed matter) that I worked in the dirt left over from the real physics. Fast forward 20+ years, and he is working on modeling semiconductor growth (like I was to a degree), and I am long gone from physics. Skipped postdoc/tenure track to go into industry post Ph.D. My impression dealing with HEP folks for many years, is that a fairly large fraction of folks in the field look down on the rest of the world. Similar with the nuclear people. This is anecdotal of course, and a small subjectively interpreted sampling. All that said ... One of the more interesting aspects of string theory is that it appears to have analogues and applications in superfluidity, and other phenomenon where you get spontaneous symmetry breaking[1], or where you have critical exponents and length scales[2]. [1] https://arxiv.org/abs/1507.05635 https://arxiv.org/abs/1507.05635 [2] https://www.cambridge.org/core/books/string-theory-methods-for-condensed-matter-physics/F9D08031D2147BD474C35ACBF97E6A28 https://www.cambridge.org/core/books/string-theory-methods-f...
chopin 9y ago
I beg to differ. You're right for the standard model. But there are other fields where this is not true. A few spring to mind: - Solid state physics. There are entire fields which are not understood theoretically such as high temperature superconductivity - Astronomy: dark matter and dark energy. There is no widely accepted theoretical model for both. Both where not predicted by any theory, either.
jules 9y ago
To say that theoretical physics has been ahead of experimental physics from 1905 onwards is not entirely accurate. In the 1960s particle accelerators had found lots of particles. At first those were thought to be elementary, but more and more were found, into the hundreds. Physicists started doubting that they were elementary. The quark model eventually explained that those hundreds of particles aren't elementary. Saying that theory is ahead of experiment also suffers from survivorship bias. We tend to forget the theoretical predictions that didn't pan out. If the theoretical side predicts 10 different possibilities and the experiments eventually find that one of those is right, that's not evidence that theory is ahead of experiment. We also tend to interpret correct theoretical predictions in a more rosy light after the fact. One of the poster childs for theoretical predictions is the positron. It is said that Dirac predicted the positron, which is true. He first considered that an electron could be in a positive and negative state, but retracted that position later and said that the positive charges were holes in an infinite negative sea, and he theorised that the proton is a negative electron. He was eventually convinced by Oppenheimer that the infinite negative sea idea didn't make sense, and that's when he predicted that there was a positron particle in 1931. But the positron had already been observed two years earlier, although those observations weren't conclusive and the conclusive experiment was done in 1932. The interplay between theory and experiment is often nuanced.

pvg 9y ago

Maybe that's cheating a little but astronomy and astrophysics have had a good run of observations which physical cosmology then chases. Most of them after 1905.

danharaj 9y ago

High energy physics isn't the only physics. It's not even the only physics that uses the shiniest toys of theoretical physics.

hpcjoe 9y ago
Heh ... in grad school, one of my friends was a postdoc working on computing bounds for the Higgs mass. He used to tell me (theoretical condensed matter) that I worked in the dirt left over from the real physics. Fast forward 20+ years, and he is working on modeling semiconductor growth (like I was to a degree), and I am long gone from physics. Skipped postdoc/tenure track to go into industry post Ph.D. My impression dealing with HEP folks for many years, is that a fairly large fraction of folks in the field look down on the rest of the world. Similar with the nuclear people. This is anecdotal of course, and a small subjectively interpreted sampling. All that said ... One of the more interesting aspects of string theory is that it appears to have analogues and applications in superfluidity, and other phenomenon where you get spontaneous symmetry breaking[1], or where you have critical exponents and length scales[2]. [1] https://arxiv.org/abs/1507.05635 https://arxiv.org/abs/1507.05635 [2] https://www.cambridge.org/core/books/string-theory-methods-for-condensed-matter-physics/F9D08031D2147BD474C35ACBF97E6A28 https://www.cambridge.org/core/books/string-theory-methods-f...

chopin 9y ago

I beg to differ. You're right for the standard model. But there are other fields where this is not true. A few spring to mind: - Solid state physics. There are entire fields which are not understood theoretically such as high temperature superconductivity - Astronomy: dark matter and dark energy. There is no widely accepted theoretical model for both. Both where not predicted by any theory, either.

jules 9y ago

To say that theoretical physics has been ahead of experimental physics from 1905 onwards is not entirely accurate. In the 1960s particle accelerators had found lots of particles. At first those were thought to be elementary, but more and more were found, into the hundreds. Physicists started doubting that they were elementary. The quark model eventually explained that those hundreds of particles aren't elementary. Saying that theory is ahead of experiment also suffers from survivorship bias. We tend to forget the theoretical predictions that didn't pan out. If the theoretical side predicts 10 different possibilities and the experiments eventually find that one of those is right, that's not evidence that theory is ahead of experiment. We also tend to interpret correct theoretical predictions in a more rosy light after the fact. One of the poster childs for theoretical predictions is the positron. It is said that Dirac predicted the positron, which is true. He first considered that an electron could be in a positive and negative state, but retracted that position later and said that the positive charges were holes in an infinite negative sea, and he theorised that the proton is a negative electron. He was eventually convinced by Oppenheimer that the infinite negative sea idea didn't make sense, and that's when he predicted that there was a positron particle in 1931. But the positron had already been observed two years earlier, although those observations weren't conclusive and the conclusive experiment was done in 1932. The interplay between theory and experiment is often nuanced.