Fundamental Equations

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Anonymous
Fundamental Equations 2016-06-09 18:10:59 Post No. 8133408
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Fundamental Equations Anonymous 2016-06-09 18:10:59 Post No. 8133408 [Report]

Which set of equations govern everything we know in the universe? Is it really just these two (in natural units)?

[math] \displaystyle (i\partial/-m)\phi=0 [/math]

[math] \displaystyle G_{\mu\nu}-8\pi T_{\mu\nu}=0 [/math]

If not, what other equation(s) need to be added to include everything? I guess you could argue that this could be added to the mix:

[math] \displaystyle H^2=\frac{8\pi}{3}\epsion-\frac{\kappa}{a^2R_0^2} [/math]

What does /sci/ think?

Anonymous 2016-06-09 18:19:53 Post No.8133427
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Anonymous 2016-06-09 18:19:53 Post No.8133427 [Report]

>>8133408
>Which set of equations govern everything we know in the universe?

no such thing

> Is it really just these two (in natural units)?

definitely not

>If not, what other equation(s) need to be added to include everything?

A lot

Anonymous 2016-06-09 18:21:18 Post No.8133429
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Anonymous 2016-06-09 18:21:18 Post No.8133429 [Report]

>>8133408
The universe is not describable in closed form.

Anonymous 2016-06-09 18:25:55 Post No.8133435
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Anonymous 2016-06-09 18:25:55 Post No.8133435 [Report]

>>8133429
proof?

Anonymous 2016-06-09 18:45:18 Post No.8133470
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Anonymous 2016-06-09 18:45:18 Post No.8133470 [Report]

>>8133408
Add the Standard Model Lagrangian but what exactly do you mean by equations that govern everything

Anonymous 2016-06-09 18:49:29 Post No.8133482
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Anonymous 2016-06-09 18:49:29 Post No.8133482 [Report]

>>8133470
A set of equations from which all other physical laws can be derived.

Anonymous 2016-06-09 18:52:47 Post No.8133487
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Anonymous 2016-06-09 18:52:47 Post No.8133487 [Report]

So far we have:

> Dirac's equation
> Einstein field equations
> Friedmann equation
> Standard model lagrangian

Can every physical process be understood from these equations, or do we need more? Are there any that can be eliminated?
I don't know much about particle physics... can Dirac's equation be derived from the standard model lagrangian?

Anonymous 2016-06-09 22:59:20 Post No.8134038
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Anonymous 2016-06-09 22:59:20 Post No.8134038 [Report]

>>8133487
Dirac is derived from standard model and friedmann is derived from einstein

Anonymous 2016-06-09 23:03:40 Post No.8134044
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Anonymous 2016-06-09 23:03:40 Post No.8134044 [Report]

>>8133408
There's a fundamental part of computer science that also relates to entropy that might also be a first principle

Anonymous 2016-06-10 08:31:05 Post No.8134739
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Anonymous 2016-06-10 08:31:05 Post No.8134739 [Report]

>>8133408
None do.
You don't understand fundamental principle of physics.
Physics doesn't aim to find a "truth".

Anonymous 2016-06-10 08:52:27 Post No.8134749
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Anonymous 2016-06-10 08:52:27 Post No.8134749 [Report]

>>8133408
>Which set of equations govern everything we know in the universe?

Physics isn't about reverse engineering the source code of the universe. Think more in terms of emulators that work "well enough" for our purposes.

H 2016-06-10 09:57:49 Post No.8134816
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H 2016-06-10 09:57:49 Post No.8134816 [Report]

>>8133487
>I don't know much about particle physics... can Dirac's equation be derived from the standard model lagrangian?
Yeah, there are lots of fermions in the standard model. If you get rid of all other particles and their interactions, you get the Dirac equation.
Likewise the Friedmann equation is just one particular solution to the EFEs.
>>8134739
>>8134749
I think most physicists believe there is a fundamental description of nature, but disagree about how close that is.
String theory is valid at all energies, unlike regular old quantum field theory, which seems to suggests it is truly fundamental.