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Ask HN: Is physics moving forward?

• dannypgh 11y ago
  This all depends on your frame of reference.
• irremediable 11y ago
  Well, to be fair, lots of computer technology advances were associated with advances in applied physics. Die sizes, MEMS, battery technology, etc. Maybe you mean more theoretical physics? I don't really have enough knowledge to be useful there.
• artimaeis 11y ago
  I'm not sure there's been any acceleration of discovery in the hard sciences. The 30-40 years have seen tech advancements roughly in line with Moore's law, which is fantastic. But that's the result of engineering advancements. There's no precedent I'm aware of to expect the same results out of the hard sciences.
  • 3JPLW 11y ago
    I'd disagree. New tools for biologists in the last 20 years have strongly accelerated the field. The trouble in Physics is that the new tools look like the LHC.
• deleted 11y ago
  [deleted]
• stared 11y ago
  As a PhD in physics - progress in pure physics is slowing down (or at least progress per scientist). The delay between a discovery in physics and a Nobel prize is getting bigger and bigger [1]. It's true for all fields, but the effect is particularly strong for physics. '''It is safe to say that late 1920s and early 1930s were the “Golden Age” of 20th century physics, when the progress was lightning-fast and new discoveries lay like low-hanging fruits. In the 1940s Dirac commented bitterly, in view of problems quantum field theory was having at the time: “Then, a second-rate physicist could do first-rate work – now, it takes a first-rate physicist to do second-rate work”. Every physicist would love to live in such “interesting times”, when a new unexplored scientific territory opens up.''' [2] So, its started decreasing quite some time. Also, as there are more an more people involved, the brainmass gets diluted. As of now there is no chance to get a photo of a concentration of luminaries as from the famous Solvay conferences [3]. So, if you (like me) read Feynman lectures of physics and know physics from 1920s-1950s, you are likely to get disappointed by the current pace. ...and just compare to recent progress in machine learning, when we can play on our computers with things, which a few years ago were thought to be out of our reach. (But it shouldn't be surprising, technologies and science do have their growth time, and usually it's finite time.) [1] http://priceonomics.com/why-nobel-winning-scientists-are-getting-older/ http://priceonomics.com/why-nobel-winning-scientists-are-get... [2] https://woodtickquarterly.wordpress.com/2011/11/17/graham-farmelo-the-strangest-man-the-hidden-life-of-paul-dirac-quantum-genius/ https://woodtickquarterly.wordpress.com/2011/11/17/graham-fa... (BTW: I recommend this book a lot) [3] https://en.wikipedia.org/wiki/Solvay_Conference https://en.wikipedia.org/wiki/Solvay_Conference
  • verelo 11y ago
    I do not disagree that things feel slower to some degree, but I'd also bet absolutely anything that 100 years from now people will look at our time and say "Can you believe they didn't understand X? There was so much low hanging fruit in 2015." The issue is that what appears simple, 100 years from now, takes a significant shift in how we're currently thinking. The problems are complex and the prior knowledge needed to get to a breakthrough is always growing, but I really do believe its self defeating to look at 100 years ago and think they had it easy as I believe people will undoubtedly say the same thing about us 100 years from now.
    • hellameta 11y ago
      I agree with you but not with respect to Physics. I believe it is very likely that in 100 years we will think "Can you believe they didn't understand X" in things like psychology and all of the new emerging cross disciplinary fields that have emerged from it. Economics is a good example as well I believe... Up until the second half of the 20th century many economists were not basing their theories on data but rather under assumptions that we are all "rational" actors. I will concede that the 'data' was not really available until the last 50yrs anyway but the 'behavioral' movement has hopefully set Economics as a whole on a 'straight' path and no doubt the next 100yrs will show the low hanging fruit which now dangle above us. How poetic. EDIT - The economics example I gave was very sweeping. Just an example.
      • btilly 11y ago
        Your belief about economics indicates that you are part of a minority paradigm that has produced interesting data but not managed to transform economics yet. If it does succeed, then your hope for it will be perfectly justified. But most such movements do not succeed. The problem is that success has to be so compelling that people who are working within different paradigms (economics have many) generally figure out that they are thinking about it wrong and need to restructure everything in terms of behavioral economics, rather than looking at behavioral economics as a low order correction term to their own way of understanding them.
• vezzy-fnord 11y ago
  Looking back over last 20 years, technology (esp. related to computers) had made extraordinary leaps forward and the pace is accelerating. Largely hardware advances that are heavily interrelated with physics. Even still, it has been incremental (though still impressive) production advances and not radical architectural redesign. Intel only got bounds checking in hardware (MPX extensions) a couple of years ago, even though this was first done over half a century ago. Software hasn't.
  • ghaff 11y ago
    Yeah, as per some of the discussion of another recent post, one of the big things that has happened over the past 20-30 years in computing is that we discovered a technology for use in digital logic circuits that has been amenable to incredible process shrinks. Certainly there's been extraordinary engineering that's gone into that shrinkage coupled with no small amount of semiconductor physics. But, for whatever other advances have been made in computing since 1980 or so, an awful lot comes back to CMOS.
• spott 11y ago
  This depends on your definition of "advances in physics". "New physics", physics that we don't already have an explanation for, is becoming increasingly rare. Our definition of "new physics" is also expanding to including things that aren't fundamentally new, just small holes in our understanding of the equations. The flip side of this is that while we already know the broad strokes, there is still a lot of work to be done in filling in the details. This work is just less glamorous and doesn't make the headlines.
  • sampo 11y ago
    > physics that we don't already have an explanation for, is becoming increasingly rare We don't understand why galaxies rotate the way they do, as the visible mass does not correspond to the rotation according to known laws of gravity. The solution is to postulate dark matter and dark energy, until things match again.
• richmarr 11y ago
  It's hard to read your question without thinking about how String Theory has dominated Physics for that entire timeframe (and more)... and how ineffective that family of models have been at progressing humanity's understanding of the broader world. If you believe Lee Smolin then advocates of String Theory have also had an oppressive effect on opposing ideas, making it hard to get tenure if you're not working on it, effectively choking off competing theories (e.g. Doubly Special Relativity, Loop Quantum Gravity, etc) I have no data or first-hand evidence, as I was only a mere Physics undergrad, but found his arguments pursuasive. String Theory (and his oscillating pals) have certainly been dominant in the scientific press, and don't seem to have come up with much. Could be a false negative though. We'll only know when someone opens the next big door.
• cozzyd 11y ago
  (Young) experimental particle physicist here. While our current progress in particle physics has slowed down since the 70's, we've still learned quite a bit in the last 20 years. For example we've observed the top quark, tau neutrino and Higgs boson. We have also learned lots of stuff about neutrinos, like that they have mass and oscillate. There has also been amazing progress in detectors, although that's mostly behind the scenes. Other fields of physics have had much more interesting discoveries though (e.g. graphene).
• batbomb 11y ago
  Physics has scaled out. There's a bunch of people working on a bunch of projects with, for the most part, narrowly defined goals. It's really to understand the implications of many of these projects when they succeed, let alone report on them. Government spending in the sciences has been extremely schizophrenic over the last 5 years. The NSF is a little more stable, but the NSF doesn't fund much of anything over 100M, which would be a relatively small experiment when spread out over 4-5 years.
• ISL 11y ago
  As someone who's been in physics for much of the last twenty years, I'd guess that things are going at about the same rate. I don't think that the rate is "crawling", though. If you look on log plots of parametrized experimental progress, progress remains linear, so it's a Moore's law like improvement on many fronts. The emergence of precision cosmology has really transformed astrophysics in the last twenty years. The solar neutrino problem is now solved entirely (and even \theta_{13} has been measured!). The lynchpin of the Standard Model (the Higgs) has been found. LIGO is likely to make first detection in the next couple of years. Graphene and topological insulators have the solid-state community buzzing. Fluorescence microscopy and nanopore techniques are making waves in the biophysics community. And more, of course. Heck, this week, the most compelling evidence yet for the long-sought pentaquark appeared. For the probes of the dark sector and of gravity, though we haven't found anything, huge swaths of parameter space (i.e. possible theories) have been ruled out. EDM searches are relentless in their searches for new physics. Someday, someone will find a reliable anomalous signal, but we can't predict when. And, if you're looking for fun hints of new physics, check out "muon g-2". The next 5-10 years will be exciting there, too, to see if the existing discrepancy between measurement and the Standard Model will survive closer experimental scrutiny. We go slow because we will go far.
  • admax88q 11y ago
    What's EDM?
    • ilzmastr 11y ago
      electric dipole movement or maybe electronic dance music http://www.int.washington.edu/talks/WorkShops/int_08_3/People/Hamilton_P/Hamilton2.pdf http://www.int.washington.edu/talks/WorkShops/int_08_3/Peopl...
  • elektromekatron 11y ago
    Given your perspective, what do you make of stuff like Umbral Moonshine http://arxiv.org/abs/1204.2779 http://arxiv.org/abs/1204.2779 and ER=EPR http://arxiv.org/abs/1306.0533 http://arxiv.org/abs/1306.0533 ?
• 98Windows 11y ago
  If you look at quantum computing [1], which is very much a part of physics, I would claim that progress is accelerating there. Its a field that is asking a lot of deep questions about reality and also spurring a lot of technological innovation. [1] https://en.wikipedia.org/wiki/Timeline_of_quantum_computing https://en.wikipedia.org/wiki/Timeline_of_quantum_computing
• mjfl 11y ago
  A good way to look at this objectively is to go to scholar.google.com, type in "physics" in the search bar, and limit your results to the past 10-20 years. You will have to filter through the books and survey articles (get a couple pages in), but you should get a picture of the more important articles in the past 20 years.
• PaulHoule 11y ago
  It is the best of times and the worst of times. In fundamental physics, the LHC is online, neutrino physics is hot, and lots is going on. Now there are a huge number of quantum theories of black holes, but no way to prove anything about them in site. The dark matter problem is a huge "anomaly" left to solve so there are still mountains to climb. In terms of practical stuff there is lots of physics in how you build a 7nm microchip. Physicists collaborate a lot with "nanotechnology" people and biologists. For instance my thesis advisor worked with experimentalists who were stretching DNA with tweezers and figured out how the AIDS virus self-assembles. Even the "dead" area of chaos theory is looking much better now that people at NASA have made a map of the earth-moon phase space which can give a km/sec or so free propulsion.
  • JohnBooty 11y ago
    Even the "dead" area of chaos theory is looking much better now that people at NASA have made a map of the earth-moon phase space which can give a km/sec or so free propulsion. This is fascinating - how can I learn more?
• naturalethic 11y ago
  Nobody here is going to like this comment but I recommend you look into Electric Universe theory and Plasma Cosmology.
  • mindcrime 11y ago
    Care you explain why exactly you think this stuff is worth considering? I have to admit, I'd never heard of either before now, but a quick reading of the Wikipedia page on Plasma Cosmology does not leave me with much enthusiasm for the topic.
  • tim333 11y ago
    I looked and Wikipedia has "As of 2015, the vast majority of researchers openly reject plasma cosmology because it does not match modern observations".
  • jboggan 11y ago
    It all sounds rather pretty but I'm not aware of a single testable hypothesis associated with it, or at least a testable hypothesis that anyone is willing to put forward and have immediately demolished. The Rosetta mission should have turned up some intense magnetic field readings if the Electric Universe theory is true . . . but it didn't. Then again the only people I know who espouse the theory can't begin to explain what electromagnetic fields are anyway.
• ape4 11y ago
  Maybe physics is in a (relative) plateau now. Just waiting for the big break through. eg ability to manipulate dark matter.
• euske 11y ago
  Has software technology gotten much advanced in the last 20 years yet? It became a lot bigger, yes, and now we have GC or type inference if you're lucky. But I'd be still afraid of writing a mission-critical part of software as well as I would in 80s. Also things like Heartbleed happened. In terms of the quality/correctness, the progress of the software industry has been disappointing to me.
  • deleted 11y ago
    [deleted]
  • jeff_marshall 11y ago
    I've got to say I'm rather amused by the notion that type inference and GC are innovations of the last 20 years. Regarding now vs. the 80s, we have much better tools for making assurance cases for critical software. So much progress has been made in both specification correctness and implementation correctness that I think the only way you could compare the two and say there hasn't been improvement is if you haven't tried to see what we can actually do now vs. then...
• sampo 11y ago
  If you have time, Lee Smolin's book The Trouble with Physics is a captivating read. https://en.wikipedia.org/wiki/The_Trouble_with_Physics https://en.wikipedia.org/wiki/The_Trouble_with_Physics Smolin makes a sosiological-historical argument, that from the 20s to 70s, the development in theoretical particle physics was done by trusting the "mathematical intuition", if the math was beautiful and predicted the existence of some particles, a bit later usually the experimental physicists found those particles. And the rewards and Nobel prizes went to those who did the math the fastest. So the whole theoretical physics adopted this style of work, when someone proposes something new that looks interesting, everyone tries to do the math as quickly as possible, to be the first to get the results. But then from the 70s to 00s, this flocking attitude was applied to string theory, and people just developed string math furiously, and it was left unnoticed that the theory was totally unrelated to any experiments. So, Smolin suggests, for 30 years the best of theoretical physics went into a direction that may be totally separated from experiments. If this turns out to be true, theoretical physics pretty much lost 30 years.
• redwood 11y ago
  There are a number of unexplained phenomena, easy to forget about but nevertheless essentially waiting on "new physics" to model.
• empath75 11y ago
  Not a physicist or a scientist, but I do follow the news, and I think there's a lot happening 'under the surface' with people working on mathematical foundations (category theory, complexity theory, homotopy type theory) that are going to surface into physics in unexpected ways in the fairly near future.
• nathan_f77 11y ago
  I really like these diagrams, as an answer to your question: http://matt.might.net/articles/phd-school-in-pictures/ http://matt.might.net/articles/phd-school-in-pictures/ You can't predict breakthroughs. A scientist might spend their entire career following their research to a dead end. That's not a failure, in my opinion. It just shows how much we already know, and I think we should honour those scientists just as much as the lucky ones.
  • hn9780470248775 11y ago
    The trouble with that diagram is that it implies that everything after that initial boundary traversal is a completely new and original contribution to human knowledge. Sadly this is not the case.
• yk 11y ago
  That depends, how do you quantify progress or rate of progress in physics? To compare directly to technology, Moore's law seems to indicate a accelerating pace of technology. On the other hand looking back to the 90ies progress in computer games, where you could expect a never seen before breakthrough each year, it seems that computers have hit a point of diminishing returns and probably the important metric is something like the log of computing power or something similar. So quantifying rate of progress is not well defined and it seems that it is possible to argue that the rate of progress has slowed down, even for computing power. The counter example would be digital video, where there was very little progress, for the average user, until divX and since the early two thousands, we went from cut scenes at 320x240, to Youtube and 4K video. Putting the measurement problems aside, progress in physics seems to be a lot less smooth and the big jump occurred in the first three decades of the last century with the discovery of special relativity and quantum mechanics plus the ongoing project of formalizing physics. That one was a complete paradigm shift towards mathematical models and towards an entirely different picture of reality. Since then the development of quantum field theories is basically just using the same trick as for quantum mechanics. ( Not trying to belittle the development of QFT, that is one of the monumental achievements of the human mind, it just pales in comparison to the development of QM. ) So, in this view the next big jump may be just around the corner or not possible for a human brain, but we will only know the answer after progress happened. ( I should cite one of the famous philosophers of science here, unfortunately I forgot which one.) As an example, string theory is currently not even wrong, because we can not build the known experiments that would enable us to test string theory. However a lot of brain power and ink was expended on its development over the last thirty years, and we simply do not have a good idea if it was worthwhile. If someone suggests a experiment that can distinguish between string theory and other models of quantum gravity, and if a string theory passes this test, then it was probably worthwhile to spend all that effort. In conclusion, I would argue that the question is ill defined and runs furthermore in epistemological problems, that is even if we would find a good definition we can not really know the answer. However, I am actually quite optimistic that a breakthrough is just around the corner. For example, I think that the connection of information theory and physics is not really understood, but concepts like entropy and information seem to crop up everywhere one looks.
• saulwiggin 11y ago
  I just finished a PhD in Transformation Optics and Metamaterials. Metamaterials are a real novel breakthrough in physics which have wide ranging applications for antennas and electromagnetic materials. Not to mention the recent confirmation of the Higgs Boson. Physics is moving along at a similar pace.
• jammycakes 11y ago
  It seems to me that ground-breaking discoveries in physics are generally getting more expensive. Up till about the early 20th century, ground breaking physics was largely "two guys in a garage" territory -- single individuals such as Newton or Cavendish tinkering in their own private laboratories using fairly modest equipment. Teenagers replicate their experiments in school physics lessons with equipment costing no more than a few hundred pounds today. Throughout the mid-twentieth century, ground-breaking discoveries were increasingly made by teams of researchers, which seem to have grown larger over time, with equipment that has become increasingly large and expensive, and sponsored by universities, companies and governments. Nowadays it seems that most ground-breaking discoveries are made by large, national or multinational teams working with equipment costing billions of dollars and processing petabytes of data. I couldn't see two guys in a garage producing their own space telescope or particle accelerator any time soon.
  • johncolanduoni 11y ago
    Most physics isn't done with space telescopes or particle accelerators; and very few groups require billions of dollars of equipment (considering the NSF budget is less than 10 billion dollars, there wouldn't be much to go around). Theoretical physics in experimentally relevant fields is about as cheap as its ever been; you really only need professors, a building, whiteboards, and travel funds. And believe me, there are a lot of experimental physicists doing excellent work with two guys in a garage levels of equipment.
• paulpauper 11y ago
  While progress may seem slower, we have a lot more people working on these unsolved problems. Also there is the fusion of abstract math and physics, which creates thousands of 'physicists' out of unwitting mathematicians. Due to the physical limitations of experiments, most forthcoming progress in physics will be purely abstract. But just because we can't test some of these theories doesn't mean we should disregard though, provided there are as few logical inconsistencies as possible.
• abdullahkhalids 11y ago
  I am surprised no one has mentioned quantum information yet. Quantum information is the subfield of physics whose goal is to understand what new information processing tasks are possible/efficient that are not possible/inefficient in the quantum world. Two such tasks are quantum computing and quantum key distribution. This field was birthed in the early 80s and has seen steady progress since then. Various architectures for quantum computing have been proposed and experimental control over them has steadily increased in each one over the last few years. While we are not there yet the sequence of results shows that we are rapidly approaching the fault-tolerance thresholds after which it will be possible to build quantum computers. Quantum key distribution is a simpler task and has already been achieved commercially. Now we are trying to increase the rates of transfer. We are slowly also relaxing experimental requirements. For instance there are protocols where you don't have to trust that your devices where not tampered with by an adversary. These are exciting times in quantum information. While important theoretical results where found in the 80s and 90s the experimental momentum today far outpaces it.
  • mjfl 11y ago
    Don't forget the new field of superconducting quantum annealers! I have high hopes.
  • stared 11y ago
    Quantum information is indeed a new field. Yet, I wouldn't compare it with 20s or 70s. In the last 20 years there was hardly any paradigm shift in that matter (don't be fooled by poor science reporting/popularizing or scientist overadvertising their results, in search for fame and grants). And for example, when I as attending conferences in quantum information (my PhD field), people were constantly lowering their expectations and making predictions more humble; much more "10 years ago we said it would be in 10 years; now we can say the same". I don't claim that there is no progress. Just that is depressingly slow comparing to the frontier fields of science in engineering. (If it were fast, believe me, I would have stayed in physics.) Of course, future may be different, but who knows... Compare it with e.g. DNA sequencing, where costs went down quite a few orders of magnitude in the last decade. Or image recognition, where in the last decade things though to be extremely hard (because of problems in 70s) like face recognition, image recognition etc - are now standard techniques.
• batou 11y ago
  As someone dipping into physics very late after a long journey on mathematics, this thread is both depressing and terrifying yet at the same time strangely motivating. I think there are some big questions without answers still. I want to have a bash at them.
• FiatLuxDave 11y ago
  As a physicist for the last 20 years, I suppose I am to partly to blame... ;) I would say that it depends on what you call physics. The areas of physics that were symbolic of advancement in the previous 20 years will not necessarily be the same areas where advances will be in the next 20 years. During the 1800s, advances in physics in the first half of the century lead to technological advances in steam power and electricity in the second half. If you thought of physics as meaning electromagnetism and thermodynamics, you might think that there were few advances in physics in the first half of the 20th century. And there were people that felt that way! But I think that nowadays we would think that Einstein's heyday was an era of major physics advances. So, maybe you shouldn't look at those areas that are reaching the plateau of their sigmoid curve, but newer areas. Classic particle physics, exemplified by the likes of Chadwick and Lawrence way back in the 1930s, leading to the explosion of the particle zoo in the 1950s, and then the diminishing returns of the LHC era, would be a good example of sigmoid curve development in Physics. If physics only means this stuff to you, then yes, it is going slower than it was. Areas of physics that have been closer to the high slope region of their development in the last 20 years: Quantum Information Theory (as noted by @abdullahkhalids) Dark Matter/Energy/whatevertheheckitis Medical Physics (from lead block linacs and xrays to IMRT/VMAT & modern imaging) Materials Science/'Condensed Matter' physics Black Hole science, esp. thermodynamics Gravity waves, or the lack thereof (interesting either way) techniques for signal/data processing and analysis (such as superresolution or single detector imaging) I'm sure there's more that I'm not aware of. Anything that is really very new is too small to get much press right now. Pretty much by definition, the new small stuff won't have the big press budget of CERN or NASA.
• johncolanduoni 11y ago
  String theory often gets ragged on for not having any direct practical applications, which is certainly true. However, some of the mathematics developed by string theory is key in theoretical work in fields where theory and experiment have a much tighter bond. For example, topological quantum field theory[1] has found widespread important applications in quantum information, and it was pioneered by none other than Witten himself. This isn't just on the theory side; experimentalists are looking at topological states of matter for a variety of applications, including quantum computing. [1]: https://en.wikipedia.org/wiki/Topological_quantum_field_theory https://en.wikipedia.org/wiki/Topological_quantum_field_theo...
• japhyr 11y ago
  I did a BS in physics in the early 1990s, but I haven't kept up with current research. Can someone recommend some good reading to catch up on what's been happening since then? I'd love a decent book about qm or cosmology that's not quite a textbook, but also takes more than a simplified approach aimed at people with no background in the field.
• brudgers 11y ago
  Lex III: Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones in se mutuo semper esse æquales et in partes contrarias dirigi. Only if something is moving backward.