Saturday Night Science: The Trouble with Physics

 

troublepThe first 40 years of the twentieth century saw a revolution in fundamental physics: special and general relativity changed our perception of space, time, matter, energy, and gravitation; quantum theory explained all of chemistry while wiping away the clockwork determinism of classical mechanics and replacing it with a deeply mysterious theory that yields fantastically precise predictions yet which nobody really understands at its deepest levels; and the structure of the atom was elucidated, along with important clues to the mysteries of the nucleus. In the large, the universe was found to be enormously larger than expected and expanding—a dynamic arena which some suspected might have an origin and a future vastly different than its present state.

The next 40 years worked out the structure and interactions of the particles and forces that constitute matter and govern its interactions, resulting in a standard model of particle physics with precisely defined theories that predicted all of the myriad phenomena observed in particle accelerators and in the highest energy events in the heavens. The universe was found to have originated in a big bang no more distant than three times the age of the Earth, and the birth cry of the universe had been detected by radio telescopes.

And then? Unexpected by almost all practitioners of high energy particle physics, which had become an enterprise larger by far than all of science at the start of the century, progress stopped. Since the wrapping up of the standard model around 1975, experiments have simply confirmed its predictions (with the exception of the discovery of neutrino oscillations and consequent mass, but that can be accommodated within the standard model without changing its structure), and no theoretical prediction of phenomena beyond the standard model has been confirmed experimentally.

What went wrong? Well, we certainly haven’t reached the End of Science or even the End of Physics, because the theories which govern phenomena in the very small and very large—quantum mechanics and general relativity—are fundamentally incompatible with one another and produce nonsensical or infinite results when you attempt to perform calculations in the domain—known to exist from astronomical observations—where both must apply. Even a calculation as seemingly straightforward as estimating the energy of empty space yields a result which is 120 orders of magnitude greater than experiment shows it to be: perhaps the most embarrassing prediction in the history of science.

In the first chapter of this tour de force, physicist Lee Smolin poses “The Five Great Problems in Theoretical Physics”, all of which are just as mysterious today as they were 35 years ago. Subsequent chapters explore the origin and nature of these problems, and how it came to be, despite unprecedented levels of funding for theoretical and experimental physics, that we seem to be getting nowhere in resolving any of these fundamental enigmas.

This prolonged dry spell in high energy physics has seen the emergence of string theory (or superstring theory, or M-theory, or whatever they’re calling it this year) as the dominant research program in fundamental physics. At the outset, there were a number of excellent reasons to believe that string theory pointed the way to a grand unification of all of the forces and particles of physics, and might answer many, if not all, of the Great Problems. This motivated many very bright people, including the author (who, although most identified with loop quantum gravity research, has published in string theory as well) to pursue this direction. What is difficult for an outsider to comprehend, however, is how a theoretical program which, after 35 years of intensive effort, has yet to make a single prediction testable by a plausible experiment; has failed to predict any of the major scientific surprises that have occurred over those years, such as the accelerating expansion of the universe and the apparent variation in the fine structure constant; that does not even now exist in a well-defined mathematical form; and has not been rigorously proved to be a finite theory; has established itself as a virtual intellectual monopoly in the academy, forcing aspiring young theorists to work in string theory if they are to have any hope of finding a job, receiving grants, or obtaining tenure.

It is this phenomenon, not string theory itself, which, in the author’s opinion, is the real “Trouble with Physics”. He considers string theory as quite possibly providing clues (though not the complete solution) to the great problems, and finds much to admire in many practitioners of this research. But monoculture is as damaging in academia as in agriculture, and when it becomes deeply entrenched in research institutions, squeezes out other approaches of equal or greater merit. He draws the distinction between “craftspeople”, who are good at performing calculations, filling in blanks, and extending an existing framework, and “seers”, who make the great intellectual leaps that create entirely new frameworks. After 35 years with no testable result, there are plenty of reasons to suspect a new framework is needed, yet our institutions select out those most likely to discover them, or force them to spend their most intellectually creative years doing tedious string theory calculations at the behest of their elders.

In the final chapters, Smolin looks at how academic science actually works today: how hiring and tenure decisions are made, how grant applications are evaluated, and the difficult career choices young physicists must make to work within this system. When reading this, the word “Gosplan” (Госпла́н) kept flashing through my mind, for the process he describes resembles nothing so much as central planning in a command economy: a small group of senior people, distant from the facts on the ground and the cutting edge of intellectual progress, trying to direct a grand effort in the interest of “efficiency”. But the lesson of more than a century of failed socialist experiments is that, in the timeless words of Rocket J. Squirrel, “that trick never works”—the decisions inevitably come down on the side of risk aversion, and are often influenced by cronyism and toadying to figures in authority. The concept of managing risk and reward by building a diversified portfolio of low- and high-risk placements (which is second nature to managers of venture capital funds and industrial research and development laboratories) appears to be totally absent in academic science, which is supposed to be working on the most difficult and fundamental questions. Central planning works abysmally for cement and steel manufacturing; how likely is it to spark the next scientific revolution?

There is much more to ponder: why string theory, as presently defined, cannot possibly be a complete theory that subsumes general relativity; hints from experiments that point to new physics beyond string theory; stories of other mathematically beautiful theories (such as SU(5) grand unification) which experiment showed to be dead wrong; and a candid view of the troubling groupthink, appeal to authority, and intellectual arrogance of some members of the string theory community. As with all of Smolin’s writing, this is a joy to read, and you get the sense that he’s telling you the straight story, as honestly as he can, not trying to sell you something. If you’re interested in these issues, you’ll probably also want to read Leonard Susskind’s pro-string The Cosmic Landscape and Peter Woit’s sceptical Not Even Wrong.

Smolin, Lee. The Trouble with Physics. New York: Houghton Mifflin, 2006. ISBN 978-0-618-91868-3.

Here is an hour long lecture by the author at the National Science Foundation discussing the issues covered in the book.

Less detailed, and addressed to a more popular audience, this is a twenty minute BBC interview with the author that concentrates on the problems he believes afflict the string theory endeavour.

 

Members have made 33 comments.

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  1. Profile photo of 10 cents Inactive

    Enjoyed this.

    Why was “Rocky J Squirrel” turned into “Rocket J Squirrel”? Please don’t tell me the fight movies were about Rocket Balboa. My pair of dimes just cannot shift that far. 😉

    • #1
    • September 13, 2014 at 12:46 pm
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  2. Profile photo of Great Ghost of Gödel Inactive

    Physics wandered off into the weeds by allowing itself to be infected by “pure” “non-constructive” mathematics in the late 19th century, made a lot of progress for some time anyway, but is now bumping into the limitations of that approach to mathematics. Physics cannot possibly clean up its act until mathematics does. Thankfully, there are <a href=”http://homotopytypetheory.org”>hints</a> of a necessary coming <a href=”http://ncatlab.org/schreiber/show/Quantum+gauge+field+theory+in+Cohesive+homotopy+type+theory”>revolution</a>.

    • #2
    • September 13, 2014 at 12:49 pm
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  3. Profile photo of Nanda Panjandrum

    As ever, intriguing, John…Thank you! Will be checking this one out…Hope to talk to you soon!

    • #3
    • September 13, 2014 at 1:07 pm
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  4. Profile photo of John Walker Contributor
    John Walker Post author

    10 cents: Why was “Rocky J Squirrel” turned into “Rocket J Squirrel”?

    Rocky’s middle initial, J, was a tribute to his co-creator and producer of the show, “Jay” Ward. Homer J. and Bartholomew J. Simpson’s middle initials are likewise an homage to Ward.

    • #4
    • September 13, 2014 at 1:39 pm
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  5. Profile photo of blank generation member Inactive

    Looks like the GLAST satellite launched back in 2008. Any results released yet showing a variation in the speed of light as mentioned in the video?

    • #5
    • September 13, 2014 at 1:56 pm
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  6. Profile photo of John Walker Contributor
    John Walker Post author

    blank generation member:Looks like the GLAST satellite launched back in 2008. Any results released yet showing a variation in the speed of light as mentioned in the video?

    The GLAST spacecraft, which was renamed the Fermi Gamma-ray Space Telescope after entering service, looks for possible signatures of quantum gravity in dependence of the speed of light on the energy of photons propagating through empty space. Gamma ray bursts in distant galaxies provide a short pulse signal containing photons over a wide range of energies which traverse a large fraction of the observable universe before being detected by Fermi. Quantum gravity theories which predict Lorentz violation should cause the speed of propagation of the most energetic photons to differ from that of less energetic photons in the burst. To date, the Fermi telescope has not observed such an effect, setting a bound which rules out many models of quantum gravity.

    This is one of the first experimental results which actually tests theories of quantum gravity. Although the result was negative, it is valuable in excluding a number of previously viable theories which we now know don’t work.

    • #6
    • September 13, 2014 at 2:23 pm
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  7. Profile photo of Percival Thatcher

    I am away from the mothership/home computer, but I believe Milt Rosenberg had a show where he interviewed Dr. Smolin. It might have been one of the old Extension 720 shows. It was both accessible and entertaining: in short, a typical Milt Rosenberg show.

    • #7
    • September 13, 2014 at 4:57 pm
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  8. Profile photo of John H. Member

    That Mexicans flee Mexico doesn’t tell you everything about Mexico…but it’s pretty close. That physicists call their theoretical failures “catastrophes” (I was just reading about the Vacuum Catastrophe, whose Wikipedia entry by the way links to equally unilluminating Turkish and Spanish articles) doesn’t tell you everything about physics…but it’s pretty close.

    • #8
    • September 13, 2014 at 6:21 pm
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  9. Profile photo of Randal H Member

    I read “The Trouble with Physics” right after I read Brian Greene’s “The Fabric of the Cosmos.” I enjoyed both books (at least what I understood of them,) but I thought Smolin’s book was a good balance to the string-theory heavy Greene. I intend to re-read Greene’s book someday to pick up on more of the “brane” thing that just went right over my head. I seem to recall the argument – Greene wasn’t necessarily espousing it, but I think he couched it in terms that “some believe” – that all we perceive as three dimensional reality is merely the projection of a two dimensional brane. Maybe I got that all wrong. At least at some level, I hope so.

    • #9
    • September 13, 2014 at 6:45 pm
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  10. Profile photo of Randal H Member

    I read “The Trouble with Physics” right after I read Brian Greene’s “The Fabric of the Cosmos.” I enjoyed both books (at least what I understood of them,) but I thought Smolin’s book was a good balance to the string-theory heavy Greene. I intend to re-read Greene’s book someday to pick up on more of the “brane” thing that just went right over my head. I seem to recall the argument – Greene wasn’t necessarily espousing it, but I think he couched it in terms that “some believe” – that all we perceive as three dimensional reality is merely the projection of a two dimensional brane. Maybe I got that all wrong. At least at some level, I hope I got it wrong.

    • #10
    • September 13, 2014 at 8:43 pm
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  11. Profile photo of Bartholomew Xerxes Ogilvie, Jr. Member

    I read “The Trouble With Physics” a few years ago and found it quite thought-provoking. I couldn’t help seeing parallels to climate science, another field of research where it is politically difficult to pursue ideas that aren’t consistent with the prevailing view. This is why I’m troubled by the idea of “consensus” being persuasive in science; there are times when the scientific community as a whole gets it wrong, for reasons that have little to do with the competence of individual researchers.

    There was a time when individual amateurs, with no public support, could make important discoveries. (Galileo and Einstein come to mind.) It seems that those days are gone, especially on the experimental side (a hobbyist couldn’t have built the Large Hadron Collider). When that kind of money is involved, I honestly don’t know how politics can be gotten out of it.

    • #11
    • September 13, 2014 at 9:11 pm
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  12. Profile photo of Larry Koler Member

    Bartholomew Xerxes Ogilvie, Jr.: I read “The Trouble With Physics” a few years ago and found it quite thought-provoking. I couldn’t help seeing parallels to climate science, another field of research where it is politically difficult to pursue ideas that aren’t consistent with the prevailing view. This is why I’m troubled by the idea of “consensus” being persuasive in science; there are times when the scientific community as a whole gets it wrong, for reasons that have little to do with the competence of individual researchers.

    I’ve come to see it this way:

    It is necessary to rely on consensus in scientific theories, data and analysis. This is the only way to get through the sheer amount and scope of science nowadays. I have strong faith that most science nowadays is either correct or going in that direction.
    Most scientists are not able to stand their ground against political pressure — this is for funding reasons and because many scientists aren’t aware of how politics really works. Scientists are co-opted all too easily.
    Theories that ARE supported by consensus AND are politically controversial need to get a second look to see if this political pressure is involved in the PRESENTATION of the theory.
    Theories that ARE NOT supported by consensus AND are politically controversial need to get a second look to see if this political pressure is involved in the DENIGRATION of the theory.

    • #12
    • September 14, 2014 at 8:25 am
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  13. Profile photo of Larry Koler Member

    Thanks, John — another very interesting post.

    You might be interested in Neal Stephenson’s article “Innovation Starvation” about his worries that science is in trouble. (He has a new book out: Hieroglyph to deal with this topic.)

    Here’s Neal:

    My lifespan encompasses the era when the United States of America was capable of launching human beings into space. Some of my earliest memories are of sitting on a braided rug before a hulking black-and-white television, watching the early Gemini missions. This summer, at the age of 51—not even old—I watched on a flatscreen as the last Space Shuttle lifted off the pad. I have followed the dwindling of the space program with sadness, even bitterness. Where’s my donut-shaped space station? Where’s my ticket to Mars? Until recently, though, I have kept my feelings to myself. Space exploration has always had its detractors. To complain about its demise is to expose oneself to attack from those who have no sympathy that an affluent, middle-aged white American has not lived to see his boyhood fantasies fulfilled.

    • #13
    • September 14, 2014 at 8:34 am
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  14. Profile photo of Great Ghost of Gödel Inactive

    Every time I think about putting (virtual) pen to paper because, hey, I’m an expert computer scientist with secondary knowledge of physics, economics, politics, etc. and I should be able to write a pretty good SF/alt-history yarn, I remind myself that Neal Stephenson has already done it, and orders of magnitude better than I ever could dare to dream of.

    • #14
    • September 14, 2014 at 10:50 am
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  15. Profile photo of Randal H Member

    Sorry, editing created this duplicate post.

    • #15
    • September 14, 2014 at 11:09 am
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  16. Profile photo of Nick Stuart Inactive

    I thought that science was settled, and the debate was over.

    • #16
    • September 14, 2014 at 2:15 pm
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  17. Profile photo of Percival Thatcher

    Every current scientific consensus started with one person saying to himself “hey, wait a minute…”

    • #17
    • September 14, 2014 at 3:14 pm
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  18. Profile photo of Larry Koler Member

    Gödel’s Ghost

    Every time I think about putting (virtual) pen to paper because, hey, I’m an expert computer scientist with secondary knowledge of physics, economics, politics, etc. and I should be able to write a pretty good SF/alt-history yarn, I remind myself that Neal Stephenson has already done it, and orders of magnitude better than I ever could dare to dream of.

    Boy, ain’t that the truth. He’s a preternaturally unique talent. I like all of his work (except I haven’t finished The Diamond Age) but especially Anathem and Cryptonomicon. I’m so glad to hear from the GLOP podcasts a while ago that John Podhoretz is reading his Baroque Cycle series. Nice to get a plug from someone of his stature.

    • #18
    • September 14, 2014 at 3:57 pm
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  19. Profile photo of Ed G. Inactive

    Bartholomew Xerxes Ogilvie, Jr.:…..(a hobbyist couldn’t have built the Large Hadron Collider)……

    Speaking of the LHC and atom smashing: are scientists involved in such endeavors reasonably sure that the results of the smashing are the constituent parts of the atom rather than simply atom fragments that happen to be somewhat regular? Not to hijack the thread, I’m just curious. If any of the knowledgeable physicists can offer a brief answer one way or the other I’d appreciate it. I’ll trust your expertise since I likely won’t read any books or papers you might reference.

    • #19
    • September 15, 2014 at 6:33 am
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  20. Profile photo of Great Ghost of Gödel Inactive

    Ed G.:

    Bartholomew Xerxes Ogilvie, Jr.:…..(a hobbyist couldn’t have built the Large Hadron Collider)……

    Speaking of the LHC and atom smashing: are scientists involved in such endeavors reasonably sure that the results of the smashing are the constituent parts of the atom rather than simply atom fragments that happen to be somewhat regular?

    Yes.

    • #20
    • September 15, 2014 at 10:18 am
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  21. Profile photo of Great Ghost of Gödel Inactive

    Bartholomew Xerxes Ogilvie, Jr.:I read “The Trouble With Physics” a few years ago and found it quite thought-provoking. I couldn’t help seeing parallels to climate science, another field of research where it is politically difficult to pursue ideas that aren’t consistent with the prevailing view. This is why I’m troubled by the idea of “consensus” being persuasive in science; there are times when the scientific community as a whole gets it wrong, for reasons that have little to do with the competence of individual researchers.

    There was a time when individual amateurs, with no public support, could make important discoveries. (Galileo and Einstein come to mind.) It seems that those days are gone, especially on the experimental side (a hobbyist couldn’t have built the Large Hadron Collider). When that kind of money is involved, I honestly don’t know how politics can be gotten out of it.

    Actually, one of the great crimes in physics research is this entirely self-serving insistence that high-energy physics can only be done with multi-billion-dollar equipment. See <https://teachers.web.cern.ch/teachers/archiv/hst2000/teaching/expt/sascha/sascha.htm&gt; for information about homebrew experiments that even include muon detection. A major subtheme of <http://www.amazon.com/The-Infamous-Boundary-Decades-Controversy/dp/0817637850/ref=sr_1_8?ie=UTF8&qid=1410802297&sr=8-8&keywords=quantum+mechanics+boundary&gt; is that many important experiments can be, and have been, performed on small scales with (relatively) inexpensive equipment.

    • #21
    • September 15, 2014 at 10:33 am
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  22. Profile photo of Duncan Winn Member

    I’ve never really gotten over the “duality” of small particles like electrons where one set of experiments conclusively proves they are wave phenomenon and anther conclusively proves they are particles. How can they be both?

    • #22
    • September 15, 2014 at 1:15 pm
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  23. Profile photo of Great Ghost of Gödel Inactive

    Duncan Winn:I’ve never really gotten over the “duality” of small particles like electrons where one set of experiments conclusively proves they are wave phenomenon and anther conclusively proves they are particles. How can they be both?

    Well, one issue is with the word “conclusively.”

    I believe it was Richard Feynman who pointed out that wave/particle duality does not mean that subatomic elements are both waves and particles—it means our definitions of “wave” and “particle” are too weak.

    • #23
    • September 15, 2014 at 1:22 pm
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  24. Profile photo of John Walker Contributor
    John Walker Post author

    Gödel’s Ghost wrote, in reply to Duncan Winn: (quoting of comments is still broken for me on Firefox and Chrome on Xubuntu Linux and Safari on the iPad):

    I believe it was Richard Feynman who pointed out that wave/particle duality does not mean that subatomic elements are both waves and particles—it means our definitions of “wave” and “particle” are too weak.

    My favourite formulation is that of Aatish Bhatia who, when challenged to explain quantum mechanics in one tweet, responded:

    Don’t look: waves. Look: particles.

    • #24
    • September 15, 2014 at 1:40 pm
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  25. Profile photo of John Walker Contributor
    John Walker Post author

    Gödel’s Ghost wrote:

    many important experiments can be, and have been, performed on small scales with (relatively) inexpensive equipment.

    Indeed…I “discovered” a diurnal variation in cosmic ray flux with nothing more than a simple Geiger-Müller tube detector, an ancient PC, and a lot of patience. By “discovered”, I mean that it was a surprise to me, and when I first found it none of the physicists with whom I regularly correspond had ever heard of such an effect. It turns out it’s due to the Earth’s atmosphere expanding when heated by the Sun, which causes primary cosmic rays to interact at an altitude depending upon the time of day.

    I went on to run this experiment for more than a year and found some other interesting effects, but I haven’t yet gotten around to writing it up for the Web.

    As Yogi Berra said, “You can observe a lot by just watching.” (Yes, I know there are many versions of this quote and it may be apocryphal. But Yogi ought to have said it.)

    • #25
    • September 15, 2014 at 1:55 pm
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  26. Profile photo of 10 cents Inactive

    John Walker,

    You can now add pictures to comments. (Sorry for the one that I added.)

    fourmilab-spaceship

    • #26
    • September 15, 2014 at 2:02 pm
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  27. Profile photo of Nanda Panjandrum

    Re: #26, I’m sorry, too, TC… <grin>

    • #27
    • September 15, 2014 at 2:06 pm
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  28. Profile photo of 10 cents Inactive

    Nanda Panjandrum:Re: #26, I’m sorry, too, TC… <grin>

    I forgot which Member posted this picture #26. It was not me.

    • #28
    • September 15, 2014 at 2:10 pm
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  29. Profile photo of John Walker Contributor
    John Walker Post author

    Bartholomew Xerxes Ogilvie, Jr.: It seems that those days are gone, especially on the experimental side (a hobbyist couldn’t have built the Large Hadron Collider). When that kind of money is involved, I honestly don’t know how politics can be gotten out of it.

    There are certainly politics (a great deal of politics) in any international endeavour such as building the LHC, but it is mostly questions of who pays for what and which countries get the contracts to fabricate parts. Many of the magnets in the CERN accelerators were made in Eastern Europe, both because you get a lot of magnet for your money there, but also because it supported their technological and industrial sector in the post-Soviet era.

    However, on the science side, there is little, if any political influence. The principal detector experiments at the LHC, CMS and ATLAS, are general-purpose detectors which can find any new phenomena which may exist at the collision energies produced by the LHC. That is to say, they are not designed to look for specific phenomena predicted by a theory. Instead, they characterise whatever comes out of a collision and leave it to the experimentalists and theorists to decide whether it’s something which can be explained by what we already know or something new.

    • #29
    • September 15, 2014 at 2:17 pm
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  30. Profile photo of Bartholomew Xerxes Ogilvie, Jr. Member

    John Walker:

    However, on the science side, there is little, if any political influence. The principal detector experiments at the LHC, CMS and ATLAS, are general-purpose detectors which can find any new phenomena which may exist at the collision energies produced by the LHC. That is to say, they are not designed to look for specific phenomena predicted by a theory. Instead, they characterise whatever comes out of a collision and leave it to the experimentalists and theorists to decide whether it’s something which can be explained by what we already know or something new.

    Sure, and I’m not really suggesting that the LHC itself is run in a biased way. But to get access to the LHC, I’m assuming you pretty much need to be affiliated with an accredited research institution of some kind. And if grad-school admissions, or faculty appointments, or other such decisions are influenced by groupthink, you’re going to end up with a paucity of research ideas that swim against the current.

    • #30
    • September 15, 2014 at 7:52 pm
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