logoalt Hacker News

ceejayozyesterday at 9:27 PM6 repliesview on HN

Not a physicist, so this may be a dumb question… but do we even know for sure it’s a problem with a solution?


Replies

KalMannyesterday at 9:38 PM

Not a physicist either but my understanding is that is that if you believe that we can discover all the laws of physics that explain how the world operates then it needs to have a solution.

Like we have formulas describing how gravity works. We can test these formulas by observing the motion of the planets and galaxies. Is this theory true? There's lots of evidence for it so it feels like it's gotta be pretty close to "the truth"

We also have formulas describing how elementary particles behave. These formulas have been tested to a very high degree of precision so it seems they've got to be close to the truth as well. But if you use both our formulas for gravitation and formulas for elementary particles you can derive a contradiction. So these two theories cannot simultaneously be true. There's got to be something wrong with them.

I suppose there's the possibility that at a certain point nature simply doesn't follow any laws and you can't possibly make sense of it.

GTPtoday at 8:29 AM

According to Sabine Hossefelder, there's no scientific basis to expect that a theory of everything exists (if I remember correctly this blog post) [1]. But I also have to say that, while I do find interesting what she talks about and I agree with her about some problems in academia she often complains about, for this very reason some other physicists don't like her and say she's wrong. But my understanding is that she still gets the Physics and Math parts right, it is her complaints about academia that some academics strongly disagree with.

[1] https://backreaction.blogspot.com/2020/07/do-we-need-theory-...

lmmyesterday at 11:12 PM

Well, the universe does something with extremely small but extremely heavy objects, unless you think that merely creating that situation will cause the universe to cease to exist.

show 2 replies
tim333today at 12:08 AM

Well nature follows general relativity and quantum mechanics so presumably they can co-exist. We just don't have a mathematically consistent theory as to how.

ktallettyesterday at 9:35 PM

So we do know that all the tiny interactions like charge of particles etc must work side by side with all the big interactions like gravity as otherwise how would anything as we know it work. However it could as easily be neither are the right way to interpret the world and there is something we are missing, or we are right and we can find a method to combine the theory of the big and the small interactions but we are missing a section. At the end of the day we can't interact in any meaningful way with more than half the matter in the universe (it's proven to exist due to a gravitational pull), so it's clear we can't experience a lot of the universe and we definitely can't explain a lot.

So yes there is a solution, but do we, as humans, have the ability to come up with it, who knows. I would say it's unlikely.