While the primary purpose of last week’s post on the laws of physics underlying everyday life was to convey information like a good blog post should, there was another agenda as well: to test the waters. This is an issue I’ve been thinking about a lot lately, but I wanted to get a better idea for how it’s perceived in the outside world. I honestly wasn’t sure whether there would be more of “you arrogant physicist, we don’t have any idea what the laws are” or “you moron, why are you wasting our time with this self-evident crap?”
So much for that ambiguity. Responses, for example at Fark and Reddit but even here in our very own comment section, displayed a greater than average internetitude, defined as a tendency to not read the article, set up straw men, and miss the point. But at least the direction of disagreement was fairly uniform. The issue under discussion is important, so it’s worth taking the time to counter the three most common arguments, from completely silly to almost-sensible.
1. Are you serious? There’s so much we don’t understand: turbulence, consciousness, the gravitational N-body problem, photosynthesis…
To which my years of academic training have prepared me to reply: duh. To conclude from my post that I was convinced we had a full understanding of any of those things represents, at a minimum, a rather uncharitable reading, given that no one in their right mind thinks we have such an understanding. Nevertheless, I knew people would raise this point as if it were an objection, which is why I was extra careful to say “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.” And then, at a risk of being repetitive and boring, I added “Again, not the detailed way in which everything plays out, but the underlying principles.” And for emphasis there was something about “the much more jagged and unpredictable frontier of how the basic laws play out in complicated ways.” Nevertheless.
The distinction I’m drawing is between the laws underlying various phenomena, and how the phenomena actually behave, especially on macroscopic scales. Newtonian gravity provides an excellent example of the difference: we certainly know the laws underlying the behavior of gravitating particles in the Newtonian regime, but that obviously does not mean we have a complete solution to the N-body problem, or even a qualitative understanding of how large collections of particles behave. It’s the difference between knowing the rules by which chess is played, and being a grandmaster. Those are not the same thing. In particular, taunting “you’re no grandmaster!” is not actually a refutation of the claim that I know the rules of chess. My claim was that we know the basic equations governing the behavior of matter and energy in the everyday regime — not that we have a complete understanding of every observable phenomenon.
It is of course completely legitimate not to care that we know the basic underlying laws. You may not think that’s interesting, or very important. That’s fine, I certainly wasn’t making any claims at all about priority or importance or interestingness. But it should still be possible to understand the claim I was making, and judge it on its own merits, such as they are.
Let me just emphasize how non-trivial the claim is. First, that there is such a thing as an “underlying” set of laws. That is, that we can think of everyday objects as being composed of individual pieces, such that those pieces obey laws that are the same independently of the larger context. (Electrons obey the same equations of motion whether they are in a rock or in a human heart.) That’s the reductionist step. Again, for people who enjoy taking offense: this is not to say that the reductionist description is the only interesting one, or to imply that the right way to attack macroscopic problems is to reduce them to microscopic ones; only that the microscopic laws exist, and work, and are complete within their realms of validity. And second, that we know what those laws are. There’s nothing in the everyday world that is inconsistent with Standard Model particles obeying the rules of quantum field theory, plus general relativity to describe gravity. Amazing.
2. We don’t even understand gravity! And the Second Law of Thermodynamics! And quantum mechanics! (Magnets! How do they work???)
Unlike the previous objection, this one is not correct-but-misplaced, it’s just wrong. But it’s wrong in an interesting way. We actually do understand gravity: it is described by Einstein’s general relativity. Not deep down at the quantum level, of course, but that’s very far from the world of the “everyday.” You might try to make some profound epistemological claim that we don’t really understand gravity, we just have a set of rules that it unambiguously obeys. Fine; I would argue that this isn’t an especially helpful distinction in this case, but in any event it’s beside the point. What I meant was that we have a clear set of rules that are unambiguously obeyed. That’s also true for the Second Law — it was explained by Boltzmann. Sure, we have to invoke a low-entropy boundary condition at the Big Bang, but guess what? The Big Bang is not within the realm of our everyday experience. Even the collapse of the wave function, which comes closest to a true mystery, doesn’t qualify. For one thing, wave function collapse isn’t something you see happening in your kitchen on an everyday basis. But more importantly, we do have a theory that describes what happens, handed down to us by Bohr and Heisenberg. You might think that this theory is unsatisfying and incomplete, and I would be extremely sympathetic. But it fits all the data we have. I’m not trying to make a deep philosophical point about the meaning of “understanding”; just noting that things obey laws, and in the everyday regime we know what those laws are.
3. You’re too presumptuous. New physics might be required to understand consciousness, or wave function collapse, or…
This comes closest to an actual argument, and I wish that the entire conversation could have focused on relatively sensible points of this form. But ultimately, I don’t buy it, not even close. Take consciousness as an example. Obviously there are a lot of things about the workings of the human mind that we don’t understand. So how can we be so sure that new physics isn’t involved?
Of course we can’t be sure, but that’s not the point. We can’t be sure that the motion of the planets isn’t governed by hard-working angels keeping them on their orbits, in the metaphysical-certitude sense of being “sure.” That’s not a criterion that is useful in science. Rather, in the face of admittedly incomplete understanding, we evaluate the relative merits of competing hypotheses. In this case, one hypothesis says that the operation of the brain is affected in a rather ill-defined way by influences that are not described by the known laws of physics, and that these effects will ultimately help us make sense of human consciousness; the other says that brains are complicated, so it’s no surprise that we don’t understand everything, but that an ultimate explanation will fit comfortably within the framework of known fundamental physics. This is not really a close call; by conventional scientific measures, the idea that known physics will be able to account for the brain is enormously far in the lead. To persuade anyone otherwise, you would have to point to something the brain does that is in apparent conflict with the Standard Model or general relativity. (Bending spoons across large distances would qualify.) Until then, the fact that something is complicated isn’t evidence that the particular collection of atoms we call the brain obeys different rules than other collections of atoms.
What would be a refutation of my claim that we understand the laws underlying everyday phenomena? Easy: point to just one example of an everyday phenomenon that provides evidence of “new physics” beyond the laws we know. Something directly visible that requires a violation of general relativity or the Standard Model. That’s all it would take, but there aren’t any such phenomena.
A century ago, that would have been incredibly easy to do; the world of Newtonian mechanics plus Maxwell’s equations wasn’t able to account for why the Sun shines, or why tables are solid. Now we do understand how to account for those things in terms of known laws of physics. I am not, as a hopelessly optimistic scientist from the year 1900 might have been tempted to do, predicting that soon we will understand everything. That’s an invitation to ridicule. Indeed, we know lots of cases where the known laws of physics are manifestly insufficient: dark matter, dark energy, electroweak symmetry breaking, the Big Bang, quantum gravity, the matter/antimatter asymmetry, and so on. We might answer all these questions soon, or it might take a really long time. But these are all rather dramatically outside our everyday experience. When it comes to everyday phenomena that are incompletely understood, from consciousness to photosynthesis, there is every reason to believe that an ultimate explanation will be obtained within the framework of the underlying laws we know, not from stepping outside that framework. An impressive accomplishment.
Yawn.
@MT-LA #44:
‘why’ is a slippery thing. What is a perfectly fine ‘why’ for me may not be for you. General relativity, when given sufficiently clear initial conditions, gives me a model that describes the properties of time. The ‘why does time progress like this’ question can be answered by saying ‘because I live in a universe with an observed matter content X, and that also obeys Einstein’s equation”. From there, I can then say everything I need to know about time, barring effects of quantum gravity.
We cannot model biomolecules, we cannot model atomic nuclei, we cannot model individual events only their statistical properties, we cannot predict masses and other SM parameters, we don’t know why 3+1 dimensions – all critical issues for everyday life. Yes, we have some laws, great, unfortunately they are mostly useless because things get too complex before we get meaningful results. This also means that we cannot know if the laws are indeed all that is needed or if we are only deluding ourselves.
All in all I don’t understand the point of these posts, if you were the one who contributed to those laws that would be one thing, or if your generation contributed at least, but you are talking about things that were already known 50 years ago. It was time to celebrate back then, now we should lament the lack of further progress instead.
@eukaryote consciousness is by definition metaphysical, so conjecture about whether consciousness is ultimately materialistic is irrelevant in a physics discussion but rather a philosophical matter. What matters in a discussion of the science behind consciousness is whether or not consciousness is the result of brain function, and whether brain function is classical or quantum mechanical. There’s no evidence consciousness is the result of anything but brain function, and there’s no evidence that brain function involves anything but classical mechanics. Conversely, there’s ample evidence consciousness is the result of brain function (e.g. results of brain damage, comas, various subjective changes in consciousness resulting from changes in brain function), and according to the best available knowledge in neuroscience, biology, and physics, the behavior of the brain is explained by classical mechanics.
I can’t disagree with Sean’s ideas here, I just don’t happen to think they’re particularly interesting (and they are smug, but when has he been anything else?). I even agree with his idea that no new physics will be needed to explain consciousness, but I think he wildly overestimates the popularity of that view. Minds as good as that of Roger Penrose, to name one, would disagree.
@bittergradstudent
“From there, I can then say everything I need to know about time, barring effects of quantum gravity.”
Maybe you should ask more of physics.
How long is ‘now’? What is ‘now’? If Time is an emergent property, how does it emerge? Into how many dimensions does ‘now’ act upon? How does ‘now’ relate to the collapse of the wavefunction of the universe? Is ‘now’ a quantum computing operation? Over how wide a distance? Into infinite space? How could that be?
Sean said – “A century ago it was very easy to point to features of everyday life that were in blatant contradiction to physics as it was then understood. ”
Make it 130 years and I can’t see what. Stability of tables? There was no reason to doubt it in those preatomic days. The shining of the Sun – heating by gravitational contraction looked preety good. Remember, by your own standard, simply not being fully understood doesn’t count – you need clear evidence of contradiction, and that was still to come.
http://www.claymath.org/millennium/Navier-Stokes_Equations/
Wrong.
@waveforms:
There are many different notions of ‘now’ depending on how you want to formulate the question. Most of them don’t have anything to do with fundamental physics. Certainly that’s not a relevant question in general relativity, where a notion of a directional time pops out of the Minkowski signature as clearly as day.
Finally, you can’t really talk about the ‘wavefunction of the universe’ without some sort of quantum gravity. And there, you would expect little packets of coherence showing up on Planck scales at the largest.
Waveforms wrote:
How long is ‘now’? What is ‘now’? If Time is an emergent property, how does it emerge? Into how many dimensions does ‘now’ act upon? How does ‘now’ relate to the collapse of the wavefunction of the universe? Is ‘now’ a quantum computing operation? Over how wide a distance? Into infinite space? How could that be?
You left out: How soon is ‘now’? When you say it’s gonna happen ‘now’, well when exactly do you mean?
(See, I’ve already waited too long.)
@bittergradstudent
I read Sean’s question as “what is everyday but we cannot describe with existing physical theories” I don’t think you are restricting the set of relevant phenomena to those that we can describe with existing equations. That would dilute Sean’s argument.
“Hey look, we can describe all phenomena with Maths!, execpt for the ones we cannot describe with maths” I don’t think that is what Sean is saying.
Sure most descriptions of ‘now’ are psychological descriptions, but ‘now’ is the only aspect of Time that we have direct experience with. And all timelines are asumptions of a series of nows, which we have no clue how to define.
Imagine a bug is riding on a light beam and flies between you and the computer screen. His time is much slower than yours, so every now point he has maps to a line (series of now moments) in your time line. So what is the length of ‘now’? Is it defined by the collapse of the wavefuntion? How can it have two different relationships to the collapse of the wavefuntion in a two foot cube of space? How could it not? So forget about consciousness, you still have a problem defining what the fundamental components are in a timeline.
Sean’s claim is pretty straightforward and correct. Those objecting fall into two categories that I can see:
1) Those that don’t really know the underlying physical principles currently understood, and how they generally apply to everyday life. They are incompetent to judge their applicability ala Dunning-Kruger.
2) Those who are ignorant of the history of science, and don’t appreciate just how many complete and utter mysteries have been solved in principle or practice over the past several hundred years.
Think of radioactive decay or spectral absorption. Suddenly we knew what the sun was made of, and what the source of its power was. The Earth’s age was no longer limited by its temperature (ala Kelvin), and the composition of objects light years away became measurable.
I suppose there might be a third category, populated by those who think supernatural concepts are meaningful (they aren’t), but that’s really a separate issue – if you can’t understand that there’s no such thing as the supernatural (existence in someone’s imagination is not sufficient evidence for existence in reality), you can’t really understand the point Sean is making.
@57 CIP
130 years ago (1880) was not pre-atomic (Dalton gave good evidence for atoms as early as 1808.) Nonetheless atomic theory was controversial among physicists until the early 20th century.
There were also well known contradictions between known physical law and known natural history — lord kelvin’s estimate for the age of the earth was uncomfortably short for geologists and biologists
Olber’s paradox was formulated in 1823 (Kelvin proposed an incorrect solution in 1901 )
In short, nothing even remotely resembling the post 1960s consensus on basic physical law in normal regimes existed in 1880.
There are several ways in which the Physics of everyday life could be not fully understood :
– we might not understand the laws we have
– there might be subtle effects from a deeper law that modify the laws we have
– there might be new laws, new areas of physics, that at present we don’t even realize
I agree that it is not too useful to postulate a “physics of the gaps” – i.e., if we don’t currently have a model for X, that does not necessarily imply that X requires new physics. That’s only useful if there is good evidence that X CANNOT be modeled with existing physics, not just if it HAS not been. It is, in my opinion, more useful to look in the past, and see ways where new physics entered into previous understanding. If you look back in the past, all three of the above situations have happened.
We may not understand the laws we have. The laws of Newtonian gravitation and Newtonian mechanics have been known for 300 years, and in some ways Newtonian gravity and mechanics seem simple, but it took about 2 centuries to understand the statistical physics of thermodynamics – or even that it was needed. Likewise, chaos theory (which is important in such a mundane field as weather prediction) was not discovered for a century after the laws of fluid motion were understood, and such a great scientist as van Neumann neither expected it, nor understood its significance. Chaos in solar system dynamics was anticipated by Poincare a century ago, but is still not fully understood (in my opinion).
There may be subtle effects of new physics we are currently ignoring. The case of General Relativity illustrates the case where there were subtle effects that indicate new laws, but that are passed over. I often wonder how long celestial mechanics could have dealt with the perihelion precession of Mercury without relativity (say, by postulating a rapidly rotating solar interior). It was only when we started dealing with the timing, as well as the direction, of photons, that Newtonian physics failed in ways that couldn’t realistically be fudged without a new theory. Of course, in actual history the theory came first, and the need for it only became apparent later. (You could say that General Relativity itself is not needed for “the physics of everyday life,” but then you must consider GPS receivers to be exotic and unusual.)
There may be new physics that we will only discover once we start looking with new techniques or tools. The case of quantum mechanics illustrates that new, fundamental, laws, may require new methods of observations to be detected. It is hard to see quantum effects at a human, everyday, scale, but if you start building (say) television tubes, they become hard to miss. (Note that, as with the GPS system, what constitutes “everyday life” itself can change dramatically with time.)
So, are one or two or all three of the above cases operating now ? All you can say is, maybe. Maybe the EPR / Bell’s Theorem results do indicate some sort of action at a distance. Maybe Penrose is right, and there is some new physics associated with consciousness. Maybe dark matter has some small, but detectable, effect in geophysics or even biology. Maybe advancing computer simulations will reveal some emergent property we didn’t expect in some physical law we thought we understood. (Consciousness may result from such an emergent property.) Most likely, probably, is that any new physics will be in some area we don’t anticipate. I have guesses and opinions about these things, but that’s all that they are. That’s what’s fun about this – you don’t know until you look.
Whilst it would be interesting to understand the macro effect of the laws, what would be more interesting is understanding why there are such laws, and what are their origins.
Sean: “What would be a refutation of my claim that we understand the laws underlying everyday phenomena? Easy: point to just one example of an everyday phenomenon that provides evidence of “new physics” beyond the laws we know. Something directly visible that requires a violation of general relativity or the Standard Model. That’s all it would take, but there aren’t any such phenomena.”
That’s only because physicists convinced themselves that laws they didn’t manage to find simply cannot exist.
In reality there are giant holes in our understanding, the biggest one is that we don’t have any laws governing single events – all of quantum physics describes only statistical properties of collections of events. We cannot explain or predict or describe what happens in the case of a single event, for example when a particular atom will decay and why then and not earlier or later, there are laws there waiting to be discovered.
Of course it is now fashionable to claim that such laws cannot exist and that the process is acausal, but it is a laughable attempt to mask our own ignorance as there is no proof whatsoever to support such a claim. The fact that you can describe the results of a dice roll using probability doesn’t mean that there is no more physics there beyond probability. In the same way the fact that quantum theory can predict probabilities is in no way a proof that there are no underlying deterministic laws governing the outcomes.
Acausality is an extraordinary claim (which hardly makes sense) and therefore requires extraordinary evidence, until we have such evidence we have to conclude that it is most likely false and that there are still fundamental laws governing our reality waiting to be discovered.
A century ago (or at any other time for that matter) people could also have claimed (and many probably did) that all the still unexplained phenomena were simply random – there were no more laws to be discovered and therefore physics new them all – of course that would have been a preposterous claim to make and it is just as preposterous now.
Moshe (17) I agree, but think that tells us all something about the reliability of the anthropic
principle in its varied obfuscating, tautologous, anthropocentric uses.
Alan (48)…it is so easy to fool scientists—ask Randi—and in 1972, wasn’t Puthoff a Scientologist?
I remember a story Frank Wilzcek told about asking Murray Gellman about Feynman’s partons—Gellman looked pensive, then confused, then brightened and said ” Feynman’s put-ons.?..you must mean quarks.” IMHO Putoff is a Puton. Same goes for Sheldrake’s morphological fields, Ben Veniste’s “water memory”, and stuff by Brian Josephson post his junction. Koestler was famously credulous. Read some Medawar for therapy. There must be other blogs where folks can empathize with this stuff–perhaps one hosted by Deepak Chopra. Often quite famous people, as they age, or even before, can go rather strange. Julian Schwinger in the last few years of his life was convinced by cold fusion.
>> the stability of chairs and tables
so why are chairs and tables really stable?
one necessary ingredient is that neutrons are slightly heavier than protons, otherwise H atoms would decay into neutrons.
why are neutrons slightly heavier than protons?
unfortunately we don’t know, because we have no clue why particle masses are what they are.
Sean argues: “What would be a refutation of my claim that we understand the laws underlying everyday phenomena? Easy: point to just one example of an everyday phenomenon that provides evidence of “new physics” beyond the laws we know. Something directly visible that requires a violation of general relativity or the Standard Model. That’s all it would take, but there aren’t any such phenomena.”
Ok, what about free choice? To invoke once more the chess game analogy: GR and the SM combined describe a game of chess in which the players have no choice.
Sorry if someone already made this point…
Isn’t the definition of “everyday life” changing all the time? I bet you’ve seen someone in the street recently who is only alive because of a sophisticated hospital scanner. Are we saying you can completely explain their presence using physics rules we’ve completely understood?
“Everyday life” for the researcher tinkering with quantum computing may be full of screens of output that theorists have differing explanations for. Which of us would turn down a chance to play tetris on a quantum computer just because the underlying physical rules weren’t completely established.
It’s a moving target.
While I largely agree with Sean’s point of view, I’ll make a slightly different quibble than others have made so far: Sean includes among the rules that are “fully understood” (if not clear in all of their consequences) the rules of relativistic quantum mechanics — quantum field theory. But I don’t believe that they _are_ understood, at least not in the same way that non-relativistic qm or classical general relativity are understood. We do understand how to do perturbation theory, but that is only approximate. We can do nonperturbative qft on the lattice, but we don’t actually know whether this converges. (We suspect it does, in the case of Yang-Mills theory, but this is an unsolved problem. Yang-Mills-Higgs is even more suspect, due to the fundamental scalar.)
So this is different from chess, where we understand the rules well enough that with arbitrarily powerful computers, we could determine the outcome of any game, and different from classical physics, where we know “in principle” how to calculate quantities to any desired accuracy.
Ray – Remember Sean’s own criterion, a clear contradiction to known physical laws in the physics of ordinary life – none of your examples meet those two stringent tests. Olbers then was no more “ordinary life” than dark energy is today. Atoms were not fully understood, but the contradictions were not yet evident – nor were their reality. Geology had no absolute dating, so the problems with the age of the Sun were still up in the air.
That said, I am pretty sure Sean is right – just not as sure as he is. I think that a century from now it is at least possible that physicists will look back and say something like – those dummies, couldn’t they see that the mass of the neutron (or muon, or something – as Wolfgang points out) was a clear signal that the SM was fatally incomplete.
>> a clear contradiction to known physical laws in the physics of ordinary life
ok, so Sean has reduced his claim to “consistent with the standard model + GR”.
but the problem is that the standard model + GR is not fully consistent itself
and as we all know, it contains several unexplained parameters (this was the point I made above).
So, in which sense do we “understand the laws underlying everyday life” ?
Also, does the Pioneer spacecraft count as an object of everyday life?
I have a counter-argument worth considering that may appeal to the philosopher-scientist in you:
It is entirely conceivable that more that one set of laws explain the set of phenomena we see in our “daily lives”. Whilst you may argue that this is irrelevant and leads to untestable hypotheses, consider that establishing the laws of physics is about prediction of future situations. Just like Newtonian gravity is no longer a “sufficient explanation of everyday life” once we start launching large numbers of satellites and using highly precise clocks, so might the standard model of physics perhaps turn out to be insufficient with widespread quantum computing. The way to avoid such a phenomenon is with physics research beyond everyday life phenomena, which is of course partly the motivation behind CERN and much space research.
So yes, perhaps we now fully understand everyday phenomena. But there is a real risk that at any moment some new “everyday phenomenon” overturns some basic law or theory of physics.
(My argument is, incidentally, a specific-case adaptation of Hume’s view on the limitations of empirical science – as much as I would love to take credit for it myself.)
I wish people would apply to this kinds of discussions the same common sense that they apply to their everyday lives. But for some reason they don’t, they like to throw it all away for the sake of sustaining some exoteric argument.
Here is what I’m talking about: that third example in which the person calls for some unknown laws of physics that could apply to the human brain because of how complex it is.
Common sense is just thrown away. How is that? Well, if someone steals your wallet in a crowded concert, it is going to be nearly impossible to find out who did it. If I tell you that your wallet wasn’t stole by the people around you, but rather, by an invisible gnome, what would be your reaction? Most likely you’d think I stole it.
For everyday life people dismiss the absurd explanations, but when things enter the realm of the unknown, common sense is discarded as some people seemingly latch on explanations that are emotionally satisfying.