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The Laws Underlying the Physics of Everyday Life Are Completely Understood
- okket 10y agoFYI: This blog post is from September 29, 2010.
- dnautics 10y agoWe do not have a good model for the structure of water.
- taneq 10y agoIf there's one good argument for this reality being simulated, it's the existence of something as simple yet so darn universally useful as good ol' H2O.
- jerf 10y agoOne of the most interesting and infuriating aspects of physics is that there are soooo many orders of magnitude between all the phenomena of interest, between the Plank scale and the smallest subatomic interactions, and between atoms and the size of things that we care about, even such things as "viruses" and "proteins", to say nothing of getting up to the macroscopic scale. And beyond that, even taking macroscopic phenomena and trying to understand things at a planetary scale or beyond can be difficult. There's about 60 orders of magnitude between the smallest things we're interested in (Plank distance) and the largest (observable universe). Holy cow. The mind boggles. It isn't a contradiction to point out that we seem to have a very, very good model of the universe's most fundamental particle processes, but still can not simply derive from that model to even very simple things of interest. In principle, we could "just" simulate the standard model and "just" simulate a lot of water molecules under the conditions of interest and "just" watch what happens. In reality, that turns out to be many, many orders of magnitude more computation than we can do. See also protein folding, where even without trying to run things all the way down to the standard model, things that we in principle fully understand require gobs of computation to approximate for what are in the real world simple things happening gazzilions of times per second in every living organism. In the other direction, witness the difficulty we have trying to improve our understanding of how the universe works at the Plank scale. One imagines that if the smallest things we had were not multiple orders of magnitude larger than the scale we are trying to study that perhaps we'd have made more progress by now, but it's like trying to determine the rules of biology when the only capability you have is the ability to sling planets at each other really hard and see what happens. The miracle is that we've learned anything at all. On that note, I've often wondered if the standard model really "works". Suppose someone with a lot more simulating power than us actually programmed it in directly and set it running, with a reasonable initial state that resembles our world. (My understanding is that inflation doesn't necessarily come out of it so we can guess that you can't just start from the big bang.) Does it really work? Is the result indistinguishable from the real world without a particle accelerator? Or is there some flaw that only comes out at scale, or does the universe crash if you create a black hole? How close are we, really? If someone waved a magic wand and said "Shazam, the standard model is now what the universe really and truly runs on!", would we notice anything different? Or would we be instantly dead because it turns out chemistry doesn't quite work right? Or perhaps at all?
- Koshkin 10y agoI don't see why Standard Model would not be able to serve as the "theoretical basis" for chemistry and beyond. On the other hand, the reductionist approach is rarely helpful, and it is not helping here, because the modeling of chemical processes can be done by applying methods of quantum mechanics and does not require particle physics.
- dnautics 10y agoModeling chemical processes through quantum mechanics turns out to be a rather inefficient endeavor, and heuristic "fictional energy" models are more accurate for lower computational cost. Farming out to humans who "seem to have a knack for folding proteins" - a homemaker in Australia, was one of the better ones IIRC - turned out to beat pretty much every ab initio effort, and many "less sophisticated, more powerful" computational efforts too.
- tamana 10y agoProtein folding seems like the kind of problem that people were better at than computers 10 years ago, before deep learning
- dnautics 10y agoexactly which deep learning technique do you propose unleashing on protein folding? Deep learning is not 'magic', it is a set of tools good at a certain subset of machine learning tasks, and the impressive thing is how many machine learning tasks can be shoehorned and contorted into the deep learning rubric, i.e. 'fuzzy classification via scoring'. It should be obvious how image recognition and voice recognition fit this rubric. "Playing Go", which does not fit this rubric obviously, I think, is conquered by deep learning because there is a discrete matrix of 'moves' which looks awfully lot like an image recognition matrix, and so a move which optimizes score ('classification') can be selected. Fundamentally one of the problems is that we don't know how to score proteins. We also don't necessarily know how to score go, but it's trivial to generate solutions by running hypothetical matches because the game outcome is deterministic, solvable, and definite. While there is a decent subset of proteins whose known structures could be used to seed a database for scoring, it is very small in comparison to the universe of possibilities (20^n, where n is the length of the amino acid chain). In short: Given an arbitrary "end-board layout" I can with our existing human knowledgebase tell you which go player has won. Given an arbitrary amino acid sequence and a proposed structure, I cannot with our existing human knowledgebase tell you if the structure is correct. Because of this limitation in creating a scoring system, while I won't say that deep learning won't be used to improve protein folding (maybe it will, indirectly) it almost certainly won't be used directly, because it is not in the same class of problem.
- macspoofing 10y agoThere's a lot of 'everyday life' we don't understand. In fact most of our scholarship is in the domain of 'everyday life'. From biology and chemistry to computer science and economics and sociology. What the author meant was that nothing that will be discovered in this domain will shake fundamental physics. Things that will shake fundamental physics won't come from 'everyday life', but rather from extreme environments like those found in particle accelerators, and through study of gravitational waves, CMB etc.
- Avshalom 10y agoNo, no. Turbulence, and especially the laminar flow -> turbulent flow transition is A) not really understood B) could absolutely have massive impact if we did understand it (obviously it's possible that that real understanding could be so complicated that the existing heuristics are essentially as good as we could get anyway).
- macspoofing 10y ago>could absolutely have massive impact if we did understand it Impact on what? On the standard model and QED?
- algirau 10y agoWe have not solved the Navier-Stokes equation for non general cases. This equations describes how the velocity, pressure, temperature, and density of a moving fluid are related. If everything was already answered, then why offer $1M to solve an equation? Fun?
- dnautics 10y ago> What the author meant was that nothing that will be discovered in this domain will shake fundamental physics. Things that will shake fundamental physics won't come from 'everyday life', but rather from extreme environments like those found in particle accelerators, and through study of gravitational waves, CMB etc. And you don't know that a priori. It's possible that with a hightened level of simulation, and accurate measurement of an unusual phenomenon, some fine structure emerges. I'm not going to hold my breath, but sometimes you are surprised. The yellow color of gold is a consequence of relativisitic effects, so it could have been entirely possible (if seemingly rather unlikely) that humanity discovered relativity from that angle instead.
- algirau 10y agothis 10000X. Im a guy that took graduate thermodynamics from the guy who discovered the statistical mechanics of the hydrophobic effect. There may be only 100 people in the world who are qualified to even describe water's molecular structure at varying conditions.
- dnautics 10y agowho was that? IIRC this is a relatively recent discovery. For example its application to the understanding of the energetics of DNA duplex formation occurred just prior to when I was in grad school (early 2000s) and around the same time to proteins...
- apo 10y agoLife is all around us. There's hardly a crevice too small, too hot, too cold, too dark, or too bright where we don't find it. But we have absolutely no idea how life got here. Pick any starting point in the earth's history and try to spin a hypothesis for how cells came to be from organic molecules and other stuff lying around. You can't do it at a high enough level of detail to even attempt the most rudimentary experiment.
- macspoofing 10y ago>But we have absolutely no idea how life got here. At a high-level, we have a very good idea how life developed and we have reasonably good ideas how life got started. The details will most likely always elude us because tracing the exact evolution of a chaotic system consisting of immense number of particles over a huge span of time will always be beyond our grasp.
- Koshkin 10y agoTrue, a single cell is an astonishingly complex system. On the other hand, science does, in fact, offer hypotheses as to the origin of life on Earth. Also, the fact that life in all its forms that exist today was able to evolve from those primitive single-cell organisms seems to me just as amazing.
- Steuard 10y agoThis is very true, and it's absolutely something that we don't understand. But Carroll's point in this blog post is simply that we have no reason to think that the ultimate answer to these questions will require some fundamental principle of physics that is not ultimately a consequence of quantum field theory (and specifically, the standard model) and general relativity as we understand them today.
- imaginenore 10y agoWe actually have pretty good ideas on how life could have started http://www.talkorigins.org/faqs/abioprob/originoflife.html http://www.talkorigins.org/faqs/abioprob/originoflife.html https://en.m.wikipedia.org/wiki/Abiogenesis https://en.m.wikipedia.org/wiki/Abiogenesis
- throwaway_exer 10y agoThis article made me feel uneasy since knowing the names of several particles doesn't mean we understand them. And superconducting would change our world, yet it's still early days for both the science and engineering of efficient applications. Maybe a follow-up is needed in 2110.
- sanxiyn 10y agoMaybe not knowing the names, but how about knowing the masses? Part of the theory is precisely that apart from some numbers we already know, there is nothing more to know about those particles.
- Steuard 10y agoMy understanding of Carroll's point here is that if we were to revisit this question in 2110, there is absolutely no reason to suspect that the ultimate explanation for superconductivity would have turned out to have required any fundamental particles or interactions other than those in quantum field theory as applied to the Standard Model (plus gravity). Certainly our ability to do calculations within those theories will probably have improved drastically by then! But there's every reason to expect that physicists of that future era will be able to say, "Physicists from 2010 were entirely familiar with the basic principles and structures that our recent algorithms explaining superconductivity are based on."
- TerryADavis 10y agofiguratively vice You_know joyful think_you_could_do_better revolution news_to_me chess ho_ho_ho I_made_it_that_way chill_out failure_to_communicate just_between_us smurfs resume hypocrite do_over fake Obama courage sing maybe_I_didn't_make_it_clear when_hell_freezes_over after_a_break and_then_what stoked adultery do_not_disturb StephenHawking not_in_kansas_anymore white_trash thats_right
- jordigh 10y agoI thought we still weren't quite sure why bicycles don't topple over or why ice skating is possible: http://www.nytimes.com/2006/02/21/science/21ice.html http://www.nytimes.com/2006/02/21/science/21ice.html https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics#Other_hypotheses https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamic... Also, have we figured out gravity? That's a pretty every day thing that I thought we didn't understand yet. Has observing gravity waves given us an answer there?
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- macspoofing 10y agoYou're correct, but you missed the author's point. He didn't say we understand everything, or that there is nothing of-value left to discover in the domain of 'everyday life'. What he meant was that anything we do discover in this domain, won't impact our current understanding of fundamental physics.
- ktRolster 10y agoI think the author is wrong. For example, 150 years ago, radio waves were unknown, but they are all around us, they are fundamental, and when they were discovered, they changed our daily lives. Another example, imagine a bushman, and asking him if he understands everything. He might say, "Yeah, that's a kangaroo, that's a bush, that's dirt....everything practical, I understand. There are things about God I don't understand, but they are far away." By defining things that you don't understand as 'not important' then you understand everything important by definition. Another example, this quote from Albert Michelson in 1894, "it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice" In other words, it is likely that people have always thought these sorts of things, and so far have always been wrong.
- pka 10y ago
- D_Alex 10y agoWikipedia has a list of unsolved problems in physics. https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_physics https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_p... Most of them might arguably not be "Physics of Everyday Life", but - number one on the list is https://en.wikipedia.org/wiki/Entropy_(arrow_of_time) https://en.wikipedia.org/wiki/Entropy_(arrow_of_time) We do not know why time moves in the direction that it does! And you cannot get much more "everyday life" than that.
- elwell 10y agoThe title is a philosophical statement; one which, to me, is brazen and absurdly proud.
- Steuard 10y agoIf you read the post, you'll see that Carroll means it in a specific and experimentally precise sense: not that "physics is finished", but simply that we have experimentally ruled out the possibility of interactions beyond the standard model (plus gravity) that are strong enough to affect the physics of everyday life in any measurable way. We absolute expect that there are things we do not know about at all (much less fully understand)! But any new interaction strong enough to have measurable effects on systems at familiar human scales would necessarily have shown up in experimental searches many years ago.
- beastman82 10y agoThis is preposterous. We don't understand gravity.
- macspoofing 10y ago>This is preposterous. Why don't you read the article? Author's second paragraph starts with: "Obviously there are plenty of things we don’t understand. We don’t know how to quantize gravity, or what the dark matter is, or what breaks electroweak symmetry." - which suggests that he may actually address your point (Hint: he does).
- sanxiyn 10y agoThis is addressed in the post. Everyday life is well explained by general relativity and there is no reason to doubt that it will continue to do so.
- tobinfricke 10y agoWe understand gravity in exquisite detail: the theory of General Relativity is our theory of gravity, and its numerous predictions have proven true again and again. But you don't even need GR for "everyday life." For that, Newtonian gravity suffices, and the entire theory of Newtonian gravity could easily be grokked by a high school student.
- gus_massa 10y agoThe GPS system needs a small but important correction due to Special and General relativity. From: https://en.wikipedia.org/wiki/Global_Positioning_System https://en.wikipedia.org/wiki/Global_Positioning_System > Special and general relativity predict that the clocks on the GPS satellites would be seen by the Earth's observers to run 38 microseconds faster per day than the clocks on the Earth. The GPS calculated positions would quickly drift into error, accumulating to 10 kilometers per day. The relativistic time effect of the GPS clocks running faster than the clocks on earth was corrected for in the design of GPS. More details: http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps....
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- smilliken 10y agoTo everyone in this thread bringing up things we don't understand yet: you're right, but probably missing the point he's trying to make. What he means is that we have a theory ("Quantum Field Theory") that is mathematically capable of predicting every physical phenomenon we're capable of observing here on earth with any instruments we've invented to date. He's definitely not saying we understand everything about the universe. By analogy, it's like saying we know conceptually what a Turing machine is and how it works, but not everything about computer science and software engineering. It may also turn out that quantum field theory is somehow wrong, in the same way that we replaced Newtonian physics with relativity and quantum mechanics. But we still use Newtonian physics in engineering because it's only wrong in ways that rarely matter in practice. I highly recommend watching Sean Carroll's talks and picking up one of his books. A few suggestions: * https://www.youtube.com/watch?v=GFMfW1jY1xE https://www.youtube.com/watch?v=GFMfW1jY1xE - "The Origin of the Universe and the Arrow of Time" * https://www.youtube.com/watch?v=Vrs-Azp0i3k https://www.youtube.com/watch?v=Vrs-Azp0i3k - "Higgs Boson and the Fundamental Nature of Reality" * http://www.amazon.com/Eternity-Here-Quest-Ultimate-Theory/dp/0452296544/ http://www.amazon.com/Eternity-Here-Quest-Ultimate-Theory/dp... - "From Eternity to Here: The Quest for the Ultimate Theory of Time"
- ktRolster 10y agoBy analogy, it's like saying we know conceptually what a Turing machine is and how it works, but not everything about computer science and software engineering. That's reverse of what he is saying. As you say, we understand the Turing machine (the most basic elements), but we don't understand everything it implies. Whereas in physics, we don't understand the most basic elements, but we do understand what those elements imply (at least, the article asserts that we do).
- macspoofing 10y ago>Whereas in physics, we don't understand the most basic elements I think he's saying we fully understand 'the most basic elements' in so far how they underpin the 'domain of everyday life'. It's a little like saying that the underlying physics behind the motion of bilard balls are completely understood with just Newtonian mechanics, even though Newtonian mechanics themselves are incomplete if applied to other domains - like explaining the motion of the planet Mercury.
- tumbas 10y agohow can revolutions happen if they are solid? what is electricity, what is electron sean? . you sound like a semi educated quack that would fiercly hold to religion of evolution although there is no prof of it. you've read it in a book so it must be true and your stupid friend says it is math and what will other dumb fucks say once they hear you do not agree with them
- tumbas 10y agothere is no more confident scientits than semi educated quasi ones
- qaq 10y ago"A hundred years ago it would have been easy to ask a basic question to which physics couldn’t provide a satisfying answer. “What keeps this table from collapsing?” “Why are there different elements?”" Ok why time is moving in one direction ?(is this basic enough question about everyday life?)
- jamesrcole 10y agoAn analogy: it's like saying the elements of Turing Machines are completely understood. All computation can (as far as we know) be described in terms of them. But that doesn't mean understanding Turing Machines is saying we understand all specific computational systems and their properties.
- Koshkin 10y agoI find it hardly surprising that physics as a body of knowledge may be finite and that we may be already close to "knowing it all". At the same time, physics is not the only science and therefore it can not claim to be able to explain "everything".
- dannypgh 10y agoCounterpoint: https://en.wikipedia.org/wiki/Shower-curtain_effect https://en.wikipedia.org/wiki/Shower-curtain_effect
- RobLach 10y agoNot to get too high-minded here but the most fundamental question of everyday life: "why live at all?" is greatly dependent on completely understanding the what we currently consider outermost fringes of physics. Free Will in a deterministic universe is non-existent so there is no physical capacity for choice, but once we breached the quantum threshold all sorts of fun concepts began emerging (like multiverses for example) that bring that lack of capacity into question.
- ImTalking 10y agoDon't understand his point. 100 years ago, we understood the physical laws surrounding the everyday things like the telegraph, the radio, the bi-plane, the early cars, etc. And 100 years from now, we will understand the physical laws surrounding everyday things like the holograph, light speed travel, the driverless hover-car, etc.
- visarga 10y agoComplexity. The fact that we know the basic laws doesn't mean we know how complex systems behave. For example, we can't predict the weather more than a few days, or the place a toddler will be at in 1 minute from now, even with all our physical knowledge.