Physics is shit

So you have this gravity law. But does particle attract itself?

I.e. does it work like (mapcar (lambda (X) (gravity X Xs)) Xs) or X should be excluded from Xs, before gravity applies?

Fucking cretin.

>>1
You exclude it or you'll end up with division by 0. The singularity.

physics has undefined behaviour and free will

>>3
proof or gtfo

>>3
particles with mass don't overlap, even in supermassive bodies

>>6
such as your mother

>>6
ever seen a particle without mass?

>>8
>>1's dick

>>1
There are no particles, only fields and perturbations in them.

Consider this: how do you know that the sun has mass and what it is?

You can choose some sphere containing the sun, measure the strength of its gravity field in enough points on the sphere, and get the total flux of the field through its surface.

Note that you should not add up magnitudes, but projections of the field on the normal, in case your sphere is off-center. Also note that you can similarly calculate the rotation of the field (called curl or rotor): http://en.wikipedia.org/wiki/Curl_(mathematics), and these two properties on the sphere completely define the the field everywhere else.

Then you posit that the space is 3-dimensional, and the flux and curl conservation rules (for spheres or other shapes that do not enclose any field sources, the flux and curl over the surface sum to zero), and you immediately get the field equations which describe the inverse square rule (square because the area of a 3d sphere is proportional to the square of its radius), but point-wise.

So then you say that these rules that describe the evolution of a field point-wise are the real shit, while the idea that the sun "attracts" stuff is an interpretation, so when this interpretation breaks as you ask "does the sun attract itself", that's OK, you just consult the real thing and it's all fine there.

It's a damn shame that http://en.wikipedia.org/wiki/Black_hole_electron doesn't work.

>>10
There are no particles, only fields and perturbations in them.
What "fields" are made of? Obviously they are discrete in the end, so there must be some kind of correlated particles.

>>10
Consider this: how do you know that the sun has mass and what it is?
Consider this: a pack of wild niggers.

Consider this - a pack of wild particles raping ...

>>1
Particles (ehh, but see >>10 and below) do self-interact whenever the question arises. This doesn't mean that they interact in the precise way you expect, particularly if your expectations are ignorant of physics.

>>11
Particles can be interpreted purely as field interactions. They are not "obviously" discrete in the end, how did you even come up with that?

>>12
consider this: because javascript will fuck it up

>>14
They are not "obviously" discrete in the end, how did you even come up with that?
Can you prove, that it's "continuous"?

>>8
ever seen a particle without mass?
If field is continuous, then it's made from infinitesimals, infinitesimals are discrete (particles) and have no mass.

>>16

Can you prove that it's, "discrete?"

>>18
Can you prove, you're not a jew?

>>8

ever seen a "particle?"

>>20
wikipedia says some scientists seen them, using special hardware, like webcam but with higher samplerate.

>>16
You're missing the point.

And I'd still like to know how >>11 came up with that.

>>16
It should be possible to have a quantized version. There's no real need for actual 'particles', 'particles' are just an emergent concept which sometimes breaks down in certain context. It's all math down there, the only question is 'which math'. I'm not betting on actual infinitesimals existing ontologically, but using reals allows for us to have simpler models until we find a more accurate discrete one. It's a shame not enough physicists care about the math they're using in their theories. I conjecture that you don't need anything more than arithmetic (with its countable infinity) and 1st-person indeterminacy (mind) to describe physics (this is automatically true if we admit a digital substition (as in, if mind uploads are possible) and arithmetic is consistent).

>>23

maybe if you try to model something with math some time, you'll understand why certain models are more appropriate in certain situations. And you know, actually try to obtain some meaningful results. Don't just set it up the way you think everything should be set up and then assume that it'll work out because it fits into the way that you think things should be.

>>24
I've only posted once in this thread, so don't assume I'm >>11 or someone else. I did say that some models are easier to work with, even if they may not match the territory exactly, but I also said that ontologically, you don't need to posit too much beyond computation (Turing-emulable) and there doesn't seem to be a way to show an actual continuum existing physically. However, ontology and epistemology are different things and if a model is useful, make practical use of it, just one should be careful and not confuse that one approximation with reality.

>>25
sorry about the assumption.

The way I see it, models are always an approximation of reality. We can see patterns using our senses and our technology, and we can describe these patterns mathematically, and we can accurately predict what patterns will result in certain situations, but we can never really know what reality actually is. We can only see the consequences of what reality is, measure it, and make predictions about it. So in that sense math has nothing to do with what reality is. It's just a tool that can be used to describe and predict things that seem to always happen in it.

>>26
So in that sense math has nothing to do with what reality is. It's just a tool that can be used to describe and predict things that seem to always happen in it.
I'm not so sure. Reality could just be math seen from the inside (such is the hypothesis of Schmidhuber or Tegmark). If reality isn't that, what do you think it is?
Also, if you think "mind uploading" is possible theoretically or practically (sometime in the distant future), that is, if you admit a Turing-emulable substitution, it can be shown that the ontology becomes more or less fixed to any computationally universal system(one can't distinguish between them), see http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHALAbstract.html for an example.
So I'd be careful when saying reality and math have nothing to do with each other, unless you're just the type who doesn't want to ask that question ("what is 'fundamental' reality?")

>>27

well, that's the thing. I could think that reality is a construct of some form, but I wouldn't be able to know. But then you get into the whole, what is knowledge thing, which is a little loose and hard to define in itself. I could guess that reality is a certain way, and I might happen to be correct by luck, but I could just as easily be wrong. And when I see a cup sitting on a table, I could think that there is a cup on the table, and I might happen to be correct, but I could also be wrong if it was actually an optical illusion. I could say that there is a 2D pattern of light representing a cup hitting my retina, but I could also be wrong if it was actually a hallucination, and the image was created within my mind. But fundamentally, something is happening. It's how I interpret it that leads me to the possibly incorrect notion of there being a cup on a table. So, I'm willing to assume that there is a reality, but when one says that reality is actually X, they are assigning an interpretation to reality, and this interpretation could be false just as easily as it could be true. It would explain a lot if reality was based in some mathematical, computable thing, quite like how it would explain a lot if there was actually a cup on the table. I don't normally hallucinate (to the best of my knowledge) and people don't normally go out of their way to build optical illusions for me (to the best of my knowledge), so I could say that the cup is likely actually on the table. And you could say that reality usually functions in accordance to mathematical laws that we have come to understand in some areas. It would make sense if it actually worked that way. But you can never know that's what it actually is. You can base models around it, and you can believe it yourself, but you'll never be able to confirm it absolutely. After all, for all we know, the laws of physics could all break in 10 minutes, with objects soaring up into the sky, and dissolving into rainbows. You wont be able to confirm that it wont happen until ten minutes from now. You could say that such an event isn't very likely, as it has never happened in the past, and if you restrict yourself to a model of reality, you could say that such an event is impossible. But the model could lead to an incorrect conclusion, and just because it has never happened before in recorded history doesn't mean it can't happen in ten minutes.

>>28
Sure, you can never truly 'know' what fundamental reality is, but that shouldn't stop you from making theories and betting on those you think are more likely (and meta-tools/heuristics like Occam's razor are good for helping you pick what theories are more probable). In that sense, it's only correct to be agnostic about most theories, however in the end, you have to bet on something if you're going to make any use of any theory, and there's always a risk that you'll be wrong.
After all, for all we know, the laws of physics could all break in 10 minutes, with objects soaring up into the sky, and dissolving into rainbows. You wont be able to confirm that it wont happen until ten minutes from now. You could say that such an event isn't very likely, as it has never happened in the past, and if you restrict yourself to a model of reality, you could say that such an event is impossible. But the model could lead to an incorrect conclusion, and just because it has never happened before in recorded history doesn't mean it can't happen in ten minutes.
I would say that is wildly improbable, but I would never claim it to be impossible. If that were to happen to me, and that I would still be conscious of these events (even less probable, consider the Anthropic Principle which states that (local) reality can't be anything that doesn't support your own existence, that is, if there are structures which don't support your own existence, you're just not going to experience them), I would try to make up hypotheses as to what is happening, my initial one would be that I might be going insane or that I'm just dreaming or hallucinating.

The only thing I will claim as impossible are concepts which contain contradictions within themselves, that is, logical impossibilities.

>>29

Yeah, I'm comfortable with making theories about things that behave in reality. If a behavior can be repeatedly observed experimentally, and if a model can be developed to fit the behavior, then I place enough faith in the model to use it, both as a base point for study, and as a tool for engineering. But one should always keep in mind that it can be possible to push the model to the limits where it no longer accurately describes what is happening, ie, you can plug in values into the model such that if an experiment was attempted with the same values, you'd likely get different results. Or one can find a situation in reality where the assumptions made in the model are no longer reasonable. But this problem can be effectively solved by developing different models for different scales, or situations, and always choosing a model that is reasonably accurate, easy to interpret, and easy to work with in an application.

Haha, yeah, I'm not sure what my reaction would be. It would probably be along the lines of "oh shit, things are going down now!"

Yeah, that makes sense. The trick with proving an impossibility is that you need some assumptions to establish the contradiction. And this gets difficult when you don't know if your assumptions are correct or not. Is the assumption false, or is the thing your are trying to prove to be impossible false? But you can still show that they can't coexist. But then if a theory was to contradict itself, then there is no issue with trusting the assumptions. The theory packages all of the assumptions, and proves itself to be inconsistent with itself.

>>31
Yeah, that makes sense. The trick with proving an impossibility is that you need some assumptions to establish the contradiction. And this gets difficult when you don't know if your assumptions are correct or not. Is the assumption false, or is the thing your are trying to prove to be impossible false? But you can still show that they can't coexist. But then if a theory was to contradict itself, then there is no issue with trusting the assumptions. The theory packages all of the assumptions, and proves itself to be inconsistent with itself.
In a way, logical contradictions or internal inconsistencies can be used to rule out some theories or to show that some properties are literally impossible.

In practice, we tend to use models that we know wrong in certain contexts because we either don't have anything better (yet) or that they are just accurate enough in the context they are applied and we can live with some error we can estimate.

>>33
nice dubs dude

>>32
Fuck you, ``faggot."