The Laws Underlying The Physics of Everyday Life Are Completely Understood

Not sure why people don’t make a bigger deal out of this fact. Physicists (and scientists more generally) are infamous for making grandiose claims about how close we are to Figuring It All Out, only to be shocked by some sort of revolutionary discoveries soon thereafter. Personally I have no idea how close we are to a comprehensive theory of absolutely everything. But I do know how close we are to having a comprehensive theory of the basic laws underlying the phenomena we encounter in our everyday lives — without benefit of fancy telescopes or particle accelerators or what have you. Namely, we already have it! That seems to be worth celebrating, or at least remarking upon, but you don’t hear it mentioned very much.

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. But we don’t need to know any of those things to account for the world that is immediately apparent to us. We certainly don’t have anything close to a complete understanding of how the basic laws actually play out in the real world — we don’t understand high-temperature superconductivity, or for that matter human consciousness, or a cure for cancer, or predicting the weather, or how best to regulate our financial system. But these are manifestations of the underlying laws, not signs that our understanding of the laws are incomplete. Nobody thinks we’re going to have to invent new elementary particles or forces in order to understand high-Tc superconductivity, much less predicting the weather.

All we need to account for everything we see in our everyday lives are a handful of particles — electrons, protons, and neutrons — interacting via a few forces — the nuclear forces, gravity, and electromagnetism — subject to the basic rules of quantum mechanics and general relativity. You can substitute up and down quarks for protons and neutrons if you like, but most of us don’t notice the substructure of nucleons on a daily basis. That’s a remarkably short list of ingredients, to account for all the marvelous diversity of things we see in the world.

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?” “What kind of signal travels from the brain to your muscles?” But now we understand all that stuff. (Again, not the detailed way in which everything plays out, but the underlying principles.) Fifty years ago we more or less had it figured out, depending on how picky you want to be about the nuclear forces. But there’s no question that the human goal of figuring out the basic rules by which the easily observable world works was one that was achieved once and for all in the twentieth century.

You might question the “once and for all” part of that formulation, but it’s solid. Of course revolutions can always happen, but there’s every reason to believe that our current understanding is complete within the everyday realm. Using the framework of quantum field theory — which we have no reason to doubt in this regime — we can classify the kinds of new particles and forces that could conceivably exist, and go look for them. It’s absolutely possible that such particles and forces do exist, but they must be hidden from us somehow: either the particles are too massive to be produced, or decay too quickly to be detected, or interact too weakly to influence ordinary matter; and the forces are either too weak or too short-range to be noticed. In any of those cases, if they can’t be found by our current techniques, they are also unable to influence what we see in our everyday lives. We have very little idea how big the region of our understanding is, compared to all that there is to be understood; but we know that it’s bigger than what we need to understand to make sense of the world we see with our unaided senses.

That’s pretty amazing. Science will certainly push forward along the frontier of phenomena that are too big or small or subtle to be detected without delicate instruments, as well as along the much more jagged and unpredictable frontier of how the basic laws play out in complicated ways. But getting the basic laws right is an extremely impressive accomplishment, especially for good old human beings who have only been doing science systematically for a few centuries. Way to go, human beings!

(See follow-up posts here and here.)

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70 Responses to The Laws Underlying The Physics of Everyday Life Are Completely Understood

  1. Uhprentis says:

    I disagree with the writer of this article.

    For one, we do not ‘understand’ most everyday life things as deeply or as often as you propose. take for example, photosynthesis which now is known to involve the quantum world in it’s process. A quote from a relatively old article on the subject in wired seems to best illustrate the idea I’m getting at which is that a lot of things we ‘think’ we understand…in fact we actually don’t.

    “The findings are wondrous in themselves, adding a new dimension to something taught — incompletely, it now seems — to every high school biology student.”

    I am certain that making the prediction that the next few decades will involve more discovery and understanding on the quantum level than anything solely in the macro world by far is not a huge gamble. We will also continue to reveal more and more ways the macro and micro worlds affect eachother as inseparable parts of the whole. Being so vastly different from eachother this relationship will certainly continue to enlighten and shape our understanding of what may be considered now ‘commonly understood’ items into entirely different ideas altogether, as in the case with photosynthesis.

  2. ed says:

    i do not understand the point of this..?

    people not questioning and striving for understanding seems like only a bad thing.

    what you see is what you get? that’s all there is? stop trying to understand anything else? don’t ask questions? don’t try to better understand ‘everything?’ i don’t get it.

    the sun clearly revolves around the earth, just look in the sky. what difference does it really make which way it happens to our every day life? it grows crops the same way either way right? clearly it makes no difference to human daily life. like i’m sure many other things that are important but ‘irrelevant.’

    also, we only understand the world ‘well’ based on our earthly 3d 1.0 gravity levels of existence and very little of anything else. things seem ‘too small’ because we are not built on that scale, if we were, they would make sense, but things ‘normal’ size that we are use to would be as incomprehensible as the questions of the universe are to us.

  3. xponen says:

    @ Uhprentis, at 26
    IMO, photosynthesis is just an example of a complex system that utilize the known physical law, but this doesn’t imply that the physical law is to be as complex as the system that utilize it. It simply says that: the organism in question is soo complex, such that it utilize physical law in a way that is magical to us. -The original physical law will remain simple even when the organism continue to evolve into a more complex form.

    In other word; the physical law of the universe will remain known, but the way it manifest itself through complexity will remain unknown.

  4. N. Peter Armitage says:

    Uhprentis wrote:

    >I disagree with the writer of this article.
    >For one, we do not ‘understand’ most everyday life things as deeply or as often as you propose. take >for example, photosynthesis which now is known to involve the quantum world in it’s process.

    But this is exactly the point. The underlying physical law is known (almost) exactly. It is the Schrodinger equation + Coulomb’s law.

    Laughlin has called this the “Theory of almost everything”. What Sean wrote mirrors alot of what is written here

    Eq. 1 is all that is needed for “almost everything.”

  5. Yi says:

    The first thing we observe in daily life might be, we are human observers, not Boltzmann brains 😉

  6. boreds says:

    @Sean #25

    Lol. Maybe I didn’t see enough funny stuff today, but I thought this response was hilarious. And hopefully equally effective.

  7. jpd says:


    but are you sure you are not a boltzmann brain?
    do you trust your brain to tell you that?
    does anybody really know what time it is?

  8. Tevong says:

    “Interesting idea. I wonder if, in part, scientists don’t want to talk about how much we know because (consciously or subconsciously) they don’t want to take away from the excitement of what lies ahead.”

    Actually i think scientists are bursting at the seams to explain how much we know, but are paralysed by the monumental task of it. The amount of understanding gained in the last century is as overwhelming as it is wonderful. It was truly the golden age of the interplay between fundamental physics, applied physics, chemistry and even biology, where a breakthrough in understanding the fundamental rules had immediate implications in understanding atoms and chemistry, which tied together with understanding stars and nucleosynthesis, the big bang, properties of materials, and enabled the technology to understand biology on the molecular level, which connects us back to chemistry etc…

    It’s really fascinating to follow this picture from top to bottom and see how it all reinforces each other, and it’s a picture that’s only been made possible in the last century by a rapid consolidation of our understanding at all levels in the sciences. But to appreciate the completeness of this picture and feel like we really do know what we know, and not take someone’s word for it, means having to explain everything from the fundamental laws and how they explain the structure of atomic elements up to why we know the brain is nothing more than a series of nerve impulses and life is nothing more than cells itself made up of molecules and how we know molecules are just atoms attached together and how it’s possible for complex life forms to evolve from just a bunch of cells and how
    cells themselves spontaneously assembled, not to mention how the rest of the universe fits in this.

    I think the challenge is for scientists to explain this so people see the picture for themselves, not just to be told that there is such a picture and they have to accept that it is pretty much complete in principle for everyday things. Thats why i wish pop science articles would focus more on explaining what we already know so people can start filling in the steps of the picture with real knowledge, rather than the fancy stuff that only means something if you already understand it in the context of this picture. Instead of blaming scientists for not communicating enough i blame science journalists for ignoring a backlog of three centuries of wonderful science the public is still blissfully unaware of.

    (edit: sorry sean, this turned into a bit of an essay.. Please delete if it violates the blog rules)

  9. Low Math, Meekly Interacting says:

    I do think it’s pretty amazing that we have a sufficient understanding to explain everything we see in daily life at the level of fundamental forces. There’s no denying that is a stunning achievement of human intellect. I also think it’s pretty amazing that so few realistic physical problems (which include the phenomena of biology, as far as I’m concerned) are tractable using direct application of the laws we use to describe those fundamental forces. I don’t say this to be snide or unappreciative. If I understand correctly, a precise description of the electronic structure of a single molecule of water from first principles far outstrips the capabilities of our most powerful supercomputers. If everything is information, and physical interactions are a kind of computation, how does nature do it?

  10. Alan Jacobs says:

    I was in graduate school during the Apollo program. Like the Renaissance in art, the 20th century was an exciting era of scientific progress….but the author misses the real point. During the first 69 years of the 20th century we moved from a horse & buggy culture to landing on the moon. Even prior to World War II sophisticated technology only circulated in academic circles. The Baby Boomers and the Moon Landings changed that. On July 20, 1969 almost every TV set in the world was tuned to Mission Control. We saw those stone faced “can do” guys in their BO stained white shirts and skinny black ties methodically follow the check list to touch down. Yes there was idealism….but objectivity, analytical procedure, and sheer guts produced one of humanity’s greatest feats. We kids wanted to be like them; the REALLY COOL kids had the super wide slide rules with all kinds of numbers….and could use it.

    Now it’s 2010. Technology is everywhere but a huge portion of high school ( and some college )graduates can’t do simple arithmetic; scientists are considered “elitist”; cynicism is rampant; the moon landing was a hoax; and lots of people want to explain measurable physical phenomena with theological or political dogma. Measurable facts are not liberal or conservative…..they are what they are….data. How we use objective data to improve society is another problem – and the real point the author should have stressed.

  11. Yi says:


    I am perhaps not sure now, but pretty sure at the next moment. Because if I were a Boltzmann brain, next moment I will most probabily be returning to the thermal equilibrium.

    On the other hand, even if I am not sure whether I am human or Boltzmann brain, this is exactly a question about daily life physics that is not answered or understood.

  12. Doug says:

    Sean @ 25: Not even the hydrogen atom?

  13. Gordon says:

    —Not Anthony MCarthy again! What happened to just lurking? All I have to do is look for the longest, most bloated and content-free posts:

    “Just assuming that everything in our experience is a manifestation of the interactions of those particles is certainly a statement of materialist faith, it’s not anything that has been reliably established in science. ”

    Of course everything in our experience is a manifestation of the interactions of those particles. Just what do you think it is? Some sort of psychic voodoo?
    The general mechanisms of evolution are understood. Stop obfuscating. You are sounding more and more like an IDer. I suppose now you will talk about irreducible complexity. This is a science blog, not the psychic hotline. What is next, spoon bending? BTW the Sophists were condemned as immoral long ago by Plato. I didn’t think one survived to the 21st century.

  14. Gordon says:

    Sean: Anthony is asking questions not for enlightenment, but rather, is playing word games. Is anything known exhaustively and totally.? Not really. But within probabilistic limits, it certainly is.
    For example, I do not “know” that a God does not exist, but the probability is so vanishingly small, that it can effectively be discounted. The sort of questions he asks are simply to deflect that he has no evidence for his positions and to put you on the defensive by making it sound like science doesn’t know something if it isn’t 100% certain, because of so-called gaps, and, for example because scientists who totally believe in evolution have minor points of disagreement. It is similar to the tactic used by the Discovery Institute in their lame and, in the words of Judge Jones, breathtakingly inane attempts to discredit evolution.
    Answering him just encourages him….it is better just telling him he is wrong rather than trying to give him an answer.

  15. Gordon says:

    Quoting one of Anthony’s favorite philosopher’s ending the Tractatus: “Whereof one cannot speak, about that, one must remain silent.” Perhaps he should take that to heart and return to the lurking ether from whence he apparently came. I believe he is a chatbot using a nonsense generator

  16. Russ Abbott says:

    Sean, I’m surprised to hear you take such a reductionist position. In “What is Life” Schrödinger said, “[L]iving matter, while not eluding the ‘laws of physics’ … is likely to involve ‘other laws,’ [which] will form just as integral a part of [its] science.” That’s true not only of life but of economics, consciousness, etc. There are lots of everyday phenomena that we haven’t yet figured out.

    For an extended explanation, see my “The Reductionist blind spot,” Complexity, 14/5 (May/Jun 2009) pp 10-22.

  17. This all sounds nice, but I feel like having read this article already 110 years ago. Just back then it was “everything is explained, we just don’t know how to shine light onto a moving body (but Ritz and a few others seem close to a solution)”. And I guess that sufficiently long ago, one could similarly say “the earth is a disk, which is good enough since no manned ship can travel far enough to make a difference (unless somebody invents sauerkraut)”. The main progress of the (late) 20th century about *everyday* stuff was about everyday stuff that wouldn’t have been there otherwise, i.e. QED (in vacuum and solid state lattices) and the electronics based on that. For everything else, we are in a similar situation as back then: all basics *seem* to be understood, and “we just have to figure out the detail of messy compound (particularly living) systems, and some weird stuff nobody cares about”. Except we didn’t then, and I don’t know if we do now.

  18. John Grigni says:

    The title of this article will probably be used to cut science spending.

  19. To echo the comments of posters up-thread (e.g., N. Peter Armitage, jpd)…. Yes, the everyday world is, to a very large extent, governed by E&M and (mostly nonrelativistic) quantum mechanics. The big challege is figuring out how the richness and complexity of the everyday world emerges from such simple underlying laws. Who would have imagined, knowing only the Maxwell and Schroedinger equations, that the low energy excitations of some 2d semiconductor structures can exhibit fractional charge and exotic statistics? While Sean couches his statement in “way to go, humanity” language, it still feels to me a bit like the classic arrogant physicist statement that all of chemistry may be expressed trivially in an undergrad quantum class. It conveys the impression that everything not bound up in Profound Questions (i.e. cosmology, high energy theory) is just detail work, and that’s simply not so.

  20. It’s a big deal for physicists that the fundamental laws are known, not so much for everyone else. Out here we’re still dying horrible deaths because our understanding of biology is so incomplete, and horoscopes are still widely used to make important decisions because science is so poorly understood. Knowing the fundamental laws is necessary but not sufficient.

  21. slw says:

    That’s nice and all but…Turbulence.

    Sorry, had to 🙁

  22. eukaryote says:

    “Of course everything in our experience is a manifestation of the interactions of those particles. Just what do you think it is? Some sort of psychic voodoo?”

    Maybe it IS psychic voodoo. If we are talking about phenomenological experience itself, for all we know, it could be anything. If conscious experience is ‘just’ particles interacting, then particles necessarily have an experiential quality, or at least the inherent potential to manifest experiential qualities. Either that, or there is something else involved entirely. There’s nothing in our physical descriptions of fundamental forces that captures the existence of experiential phenomena. At least as far as we have developed those physical descriptions.

    I’m not saying that there is something supernatural, or even non-physical involved in conscious experience, just that there must be more to the Physical than that which can be described by our conventional models. I think that’s pretty important, since for me at least, that a big part of everyday life.

  23. Gordon says:

    ie “There is more in Heaven and Earth, Horatio, than is dreamt of in your philosophy”
    Actually, not. Sure consciousness, for example, cannot be “explained” in an experiential way by interaction of particles, but it is surely caused by this, as is everything else, including Anthony.

  24. Sorbit says:

    Please tell us something we don’t know. If you want to “rejoice” that our knowledge of Newtonian physics allows us to understand and predict most everyday phenomena with great accuracy, fine. But that does not mean we suddenly understand everything as well as we understand Coulomb’s law and electrostatics. I am sure you know about emergent phenomena. What you say is like saying that since we understand physics so well we understand evolution. But the behavior of particles can by no means automatically predict natural selection, speciation etc.

    Perhaps that’s why you used the words “account for”. Then it makes more sense. But that’s a far cry from using the word “explain”. As P W Anderson said in his classic Science article, the explanatory arrows don’t necessarily point downwards. It is not possible to directly extrapolate downwards from the behavior of societies to the behavior of subatomic particles. Big gap there. So your exultation in the understanding of the physics of daily life is not entirely unjustified, but far from making us satisfied with understanding the world.

  25. Alan says:

    I have always thought that consciousness was a very difficult one to crack. I have been following recently a little of the work of Prof. David Chalmers, one of the leading philosophers of mind:

    who has the largest collection of papers on the subject. If anyone can summarize that lot and come up with some nice principles behind it, I would be interested. Look for his interviews on consciousness and quantum physics on:

    This is a really great (!) site (as is this, of course) with the best interviews I have seen with leading physicists (e.g. Andrei Linde), philosophers and mind scientists. This is a wonderful achievement by Dr. Lawrence Kuhn, who brings them all together.

    Just a few ideas. Could it go a little along these sorts of lines? Let’s go (sort of) quantum! Prof. Frank Wilczek (Nobel 2004-Physics) made some interesting comments a few years ago.

    “The leading interpretations of quantum theory introduce concepts that are extrinsic to its equations (“observers”), or even contradict them (“collapse of the wave function”). The relevant literature is famously contentious and obscure. I believe it will remain so until someone constructs, within the formalism of quantum mechanics, an “observer”, that is, a model entity whose states correspond to a recognizable caricature of conscious awareness; and demonstrates that the perceived interaction of this entity with the physical world, following the equations of quantum theory, accords with our experience. That is a formidable project, extending well beyond what is conventionally considered physics”. (interesting last sentence)

    Note that Wilczek says “concepts that are extrinsic to its equations”. So awareness acting on the causal Schrodinger equation gives experienced results. So what IS this awareness and where exactly does it exist?

    Does this mean that there is something outside of the physics which must come in to “collapse the wave fuction”. Henry Stapp, the quantum physics expert, has written extensively theoretically on this:

    where he says that there is a “psychological process” necessarily outside of the quantum formalism which must act, otherwise you never get a collapse to a real measurement. He says that this “psychological process” or “awareness” (Wilczek) in itself is not descibed by physics. Stapp is also the physicist working with AWARE Project team members (world-wide academic near-death experience research project).

    Also Dr. Bruce Rosenblum and Dr. Fred Kuttner (also see the arxiv) address this in their book, Quantum Enigma:Physics Encounters Consciousness (being republished late 2010 by Oxford University Press, note)

    where they say every interpretation of quantum theory needs an observer. They highlight the problem of consciousness. Can’t wait for it to come out.

    Does this mean that “awareness” somehow has some other physics associated with it? Can it, for instance, exist independently? If so, why does the universe have such properties that allow this to be so? Lots of questions I’m afraid – no answers.
    Philip Goff is an interesting academic philosopher here in the UK, who argues that consciousness may be fundamental in reality.

    So there is real academic physics and philosophical (notwithstanding Stephen Hawking’s recent dismissive comments on philosophy) work being done on this. Maybe it will pan out and become a deep physics research subject.