Which of the Basic Assumptions of Modern Physics are Wrong?

http://blogs.scientificamerican.com/observations/2012/05/24/fourth-fqxi-essay-contest/

by cpeterso • 14 years ago

28 48 14 years ago

blogs.scientificamerican.com

The real problem is testing 'theories merging'

There are several areas where relativity and quantum mechanics merged, for example, in the discovery and theory of antimatter

But most of the experiments of relativity were on 'big things' like planets, and quantum mechanics on 'small things'

And between them, the real mystery: gravity. General relativity knows a lot about what gravity does but not so much about where it comes from

Edit: fixed GR for SR

iskander• 14 years ago

s/Special relativity/General relativity

Special relativity ignores gravity altogether, whereas general relativity sneaks gravity into the relativistic framework by equating it with curvature.

Both theories are, to me, frustratingly intangible. Like you said, we don't really know where gravity comes from. Really, we don't even have any sort of good intuitions for how to describe what it is. Stuff resists being shoved around. Stuff also attracts other stuff to itself. Einstein tells us these are both symptoms of stuff being curvature. It's all a bit too abstract for my taste (that is, I hope a more tangible/intuitive model will eventually win out). Field equations are predictive but not really descriptive. Is there a mechanism in there somewhere?

raverbashing4• 14 years ago

Oops, true! I mixed GR and SR

klodolph• 14 years ago

The problem with tangible/intuitive models is that our sense of what is tangible/intuitive is based primarily on our millions of years living in the Newtonian realm of the universe.

chii2• 14 years ago

> Both theories are, to me, frustratingly intangible

Yes, and it is frustrating. However, like you, a lot of laymen assumes that these theories can be explained in terms of analogies with "everyday life" things. I recently watched all of Richard Feynmen's lectures (the easiest to understand is "the character of physical law" http://en.wikipedia.org/wiki/The_Character_of_Physical_Law),and in it, he explained, quite well, what it means to have a mathematical law. It goes on to some detail explanation of what quantum chromodynamics is, and how photons' behaviour cannot possibly be analogous to anything you can experience at the macro scale.

I understand your frustration (since i feel the exact same) - why is it that we have advanced so much, and yet still have no idea what inertia really is? Or mass for that matter. We know how to predict things from using various mathematical laws, but i think we are no closer to understanding "the truth", than 100 years ago. Perhaps it is impossible.

or perhaps, in the next century, or the next millenium, humans will look back, and see today's physics being just as primative as what we would see the cavemen's theories of the world is.

morpher• 14 years ago

Be careful not to conflate special (SR) and general relativity (GR). SR has nothing to say about gravity, and, as you point out, has already been successfully merged with Quantum mechanics to form relativistic quantum field theory (Dirac's early versions of which led to the proposal of antimatter). It is GR that describes "what gravity does", and which is difficult to enmesh with quantum mechanics.

fidotron• 14 years ago

I think it's fairly simple in that the overwhelming majority of people (including most physicists) haven't got an intuitive grasp of exactly how relativity works. This possibly includes Einstein.

It wouldn't surprise me one bit to find out that the basic assumptions are not flawed at all, but that whole piles of stuff is being assumed in proofs regarding expected consequences of these things which prove to be complete nonsense.

The other aspect of it is mathematics itself, which is probably not up to the task.

genwin• 14 years ago

I'm convinced that even if someone did prove that a basic assumption of modern physics is wrong, it would automatically be assumed in turn that the author is a crackpot, hence the work can be ignored. I'm convinced that the physics community isn't interested in the slightest in new ideas. Of course I'm automatically a crackpot (even beyond a conspiracy theorist) for even suggesting that.

As an example to how bad things have become in the realm of physics, it's safe to say that the vast majority of thinking adults believe that black holes exist, because so much major media has told them so. But when you look deeper you find that there's no definitive evidence. Sites like the Chandra X-Ray Observatory admit that, deep in their FAQ, but in words that many people can misconstrue as a technicality. When I point out in physics discussions that that there's no definitive evidence of black holes, I'm automatically labeled a crackpot, especially by the working physicists. One of my books suggests that this is a grant problem, as in black holes bring in a lot of grant money, so physicists must be careful to pretend that black holes are a definite reality in nature.

aaronbrethorst• 14 years ago

reference?

daeken• 14 years ago

I think the problem here is that you're conflating the absence of evidence with the evidence of absence. There's definitely no definitive evidence for the existence of black holes, but (as far as I know) we have no evidence that contradicts current models.

Science works by coming up with a nullifiable hypothesis, then seeing how it holds up as evidence is gathered. When you see contradictions, you adapt your model. I think you're missing the middle step, where you see contradictions.

2muchcoffeeman• 14 years ago

Not to mention that "black hole" and "dark matter" are sort of place holder names that end up sticking.

These phenomena are also attempts to fix the old model because they didn't produce the correct predictions. Physicists are doing exactly what the OP would like them to do.

Paradigm shifts are also very hard. Your current models predict a lot of things very very accurately. Just look at all the stuff we've built. A new model has a lot to live up to if we want to use it.

benwan8• 14 years ago

We have logical evidence that contradicts current models, namely the black hole information loss paradox, a real paradox.

UnFleshedOne3• 14 years ago

"By detecting very little energy from these black hole candidates, we have new proof that event horizons exist," said Michael Garcia of the Harvard-Smithsonian Center for Astrophysics, Cambridge, MA. "It's a bit odd to say we've discovered something by seeing almost nothing, but, in essence, this is what we have done."

http://science.nasa.gov/science-news/science-at-nasa/2001/as...

benwan8• 14 years ago

That makes the point you're replying to. "The most straightforward explanation for our observations is that these objects have event horizons and, therefore, are black holes." No, another even more straightforward explanation is that it's just an extremely dense object that's not a black hole. Even in Einstein's theory, an "almost black hole" suffices. Nothing mentioned in the article favors the former over the latter.

InclinedPlane4• 14 years ago

I don't see that to be the case. Physicists have been giving their utmost to try to crack open the standard model and prove it wrong for decades. And the same is true elsewhere as well. We thought we had a pretty good grasp on the nature of the expansion of the Universe, but it turned out that the expansion is accelerating. That was a huge reformulation of cosmology. We thought we knew about planetary formation, but once we started finding exoplanets we discovered many of our assumptions were wrong.

As far as black holes, we have not 100% direct evidence of them, but we do have many independent and very strong lines of indirect evidence. For example, we can see stars in orbit around an incredibly massive object at the center of our galaxy (Sgr A*) that is not luminous. There are no models that make sense for anything that could be so massive and so dark. Black holes are the only theory which fits all the evidence we have, that's how science works.

tybris2• 14 years ago

Well, that's how physics works. Physics is stupefyingly strict about its methods. Most sciences don't put quite as much value into models. The problem is that in a desire to strictly follow the method, physicists have become complacent with regards to extraordinary claims. Sure, the universe is full of dark matter, connected by tiny strings, in between folded up dimensions, but gravity is leaking away into parallel universes, since that's what the model predicts (rather than it just being a mathematical anomaly arising from botched assumptions). It's comparable to an economic model that describes inflation as the work of invisible leprechauns who increase prices during the night. Sure, it might make accurate predictions, hell, it might even be true, but you should not put any value into it unless there is evidence that the universe actually works in the extraordinary way the model claims it does.

Biology has followed a much better path over the past century, and biologists are rapidly building up an extremely thorough understanding of how biological systems work without relying heavily on algebraic models. Physics fails to provide explanations for even the most basic physical phenomena like motion. It's effectively just assumed to exist as a law because some authoritative physicist said so and all other models rely on it.

evincarofautumn• 14 years ago

A scientific theory is a low-resolution picture of the truth.

benwan8• 14 years ago

Black holes are not the only theory which fits the evidence we have. Simply add 2M to the first 2 r's in the Schwarzschild metric (the equation used to confirm black holes), and you get a metric that fits all the evidence but doesn't predict black holes, hence doesn't raise the black hole information loss paradox, and so isn't incompatible with quantum mechanics that way. That's well known in the cosmological community, but ignored.

tybris2• 14 years ago

In all other sciences, if you find a model that predicts something as self-contradictory as a black hole or dark matter, you shrug, figure your assumptions are wrong, and start over. In physics you announce the splendiferous wonders of the universe.

benwan8• 14 years ago

Don't forget dark energy, also (like dark matter) invented to fit the observations. How many hundreds of $millions of taxpayer money will be spent searching for it? These inventions are keeping many scientists employed, it seems. If they went back to correct the mistakes (like any good software developer) there might be a mass layoff.

mikeash• 14 years ago

Did you miss the whole FTL neutrino thing that happened not very long ago? Physics seems to be pretty open to new ideas to me. Even though that was ultimately shown to be an error, no crackpottery was ever suggested.

planetguy2• 14 years ago

I'm convinced that even if someone did prove that a basic assumption of modern physics is wrong, it would automatically be assumed in turn that the author is a crackpot

Well, since 100% of "proofs" that the basic assumptions of modern physics are wrong over the last century have, in fact, come from crackpots it's a pretty good working assumption.

I'm convinced that the physics community isn't interested in the slightest in new ideas.

Uhh, nope, the physics community is extremely interested in new ideas. We sit around generating 'em all the time. We're not especially interested in outsiders who come to us with claims that they've proved some fundamental physics result, though, for the same reason that we're not particularly interested in Nigerian princes who email us offering us millions of dollars in return for assistance in moving money out of the country: those things just tend to have a ridiculously high failure rate.

If I weren't interested in new ideas, why the fuck would I be a physicist? For the chicks?

If ever someone bearing all the hallmarks of a crackpot does come up with a fundamental new advance in physics, though, I'm convinced that this will eventually bubble to the surface. No such luck for the real Nigerian prince though.

Sure. That's also true if you replace "black holes" by "zebras". Do zebras exist? I've never seen one! I mean, I have, but it could easily have been a carefully dyed horse.

I think the level of evidence for black holes is not quite as strong as the evidence for zebras, but I think it's reasonably congruent with the level of confidence among physicists that they exist.

raverbashing4• 14 years ago

"Well, since 100% of "proofs" that the basic assumptions of modern physics are wrong over the last century have, in fact, come from crackpots it's a pretty good working assumption."

Oh, please, which ones?

Maybe the crackpots that challenged the notion that light is a wave and never behaves as a particle

Or maybe the idiot that thought that massive objects can bend light.

And yes, Albert Einstein was considered an idiot and a crackpot. After all, he was just a patent office clerk.

"Uhh, nope, the physics community is extremely interested in new ideas". BS. No, the majority is not interested in that. They're interested in grants and the status quo

They only 'accept' the new ideas when the evidence is overwhelmingly in the favor of the new idea and they'll look like idiots if they don't accept it.

You may call it skepticism, but I call it cowardice. And it's very easy to hide behind the skepticism veil, but guess what, it doesn't bring a Nobel home.