/sci/ - Science & Math

Physicists.

Energy is an abstract concept.

Can you explain your question a little more? Are you asking why there is something rather than nothing? Wasn't there a video on that and it gets posted all the time? Hm . . .

Physics doesn't seek to answer these philosophical questions

It is only a model

Ideally a predictive one

>yfw the first person to give a basic understanding of energy was a brewer not a physisist

>>2349349
I mean how did energy originate, because I feel that could be the one lapse of reasoning common to both science and religion as far as I can see, giving religion the benefit of the doubt and assuming everything in religion is metaphorical.

So I turned to physicists for an answer but, >>2349353 gave me an interesting answer.

>>2349365
There is no lapse. And as already stated, we can predict how it would happen and how it evolved but not WHY. That's not a physics question. How did energy originate? Well, uncertainty principle let's an inflaton field be created and fill the universe with energy. WHY did that happen? That's not how shit works, it happened because it did. It's physics.

>>2349414
That makes the baseless assumption that the laws were the same before energy was created as they are now

>>2349414
I assumed astrophysics/ plasma physics might have an answer to "why"

to say it is because it is, is as circular as religion to me

>>2349435
>>2349452
You need to stop trying to make science into a religion and learn what the fuck falsifiability is.

Or maybe you guys are right, you're smarter than anyone else who has ever lived and you can see why EVERYONE else is wrong. Shut the fuck up and read about it, don't ask a question and then when you get a relevant, valid answer piss it away because "it seems circular to me". Well it's not so fuck off.

>>2349452
There are many things we claim they are just because they are

Our space that we feel and explore is three dimensional.

There is no reasoning behind it. Nor does saying it was intended that way by a third party add relevance to the scenario.

Perhaps some time into the future we will find that there is no other mathematical solution to our universe than 3 dimensions. In that case, the only one who will look like a fool is the one that tried to explain the unexplained with the unexplainable.

>>2349472
>Valid answer
>God did it

Pick one

Some plausible possibilities:
1. Net energy of the universe is zero.
2. Energy conservation does not apply at the Big Bang.
3. There was a universe before the Big Bang where the energy came from.
At the moment, we don't know.

>>2349472
>He doesn't know what baseless means

OP don't listen to anyone here on 4chan. We're opinionated and want to believe that we have the real answer right now but we don't and neither does anyone else in the world.

You are on your own with this one.

>>2349478
I never justified the unexplainable, I just wanted to know the opinion on the matter. Explainable or not, it is beautiful in now how it manifests in our universe. I meant to imply that religion doesn't understand, and science doesn't understand YET.

>>2349472
stop raging, when did I ever say anything was wrong. I just said there is a gaping hole. Does not make the rest of what is known untrue.

>>2349504
>Does not make the rest of what is known untrue.

Actually it very well may do, one of the reasons 'scientists' hate change is because if it turns out they were wrong then they'd have wasted years of their lives on nonsense

>>2349297
I assume by higher level you mean least action, symmetries, group theory, and nothers shit. Unless you aren't that advanced?

>what is the origin of energy

Time

anything else? OP

>>2349504
There is no gaping hole. We have a sound understanding of the concept of energy and it is coherently within our models of physics. This is all in spite of our inability to unify the respective theories

Yes, the universe is beautiful. Everything is in its perfect place for if it were not, we would not be here to observe it. No matter the statistical extremes it took to overcome for the universe to be so finely tuned as it is, the outcome will only be a universe where there is a cognitive being to observe it.

>>2349525
>There is no gaping hole.

So where did energy come from?

>>2349523
sUPER Smartfag is sUPER smart

>>2349533
Already been explained.
>>2349414

>>2349523
No not that high.

>>2349525
I never have doubted the extent of our knowledge, just this once. Regardless I'm considering what >>2349495 said.

>>2349538
See
>>2349435

>>2349533
Are you really this dense?

It's origins are not relevant. We can show relations it has with other concepts such as mass and time. We can do all we possibly need to do with what we understand of energy. There is no means nor reason to explain the philosophical question of "how energy?".

>>2349560
Under what framework?

>>2349549
It may not be relevant to you but you must understand that it is to others. Besides the point of sentience is to answer questions unknown. I'd rather ask physicists than ask some philosophy majors for their take on it.

>>2349523
agreed

Time would be the generator associated with energy

>>2349549
>Where did energy come from
>That's not relevant

Babbysfurt traul

>>2349547
No, what is baseless is assuming that the rules have changed when there is no observational evidence that would point us to that conclusion. Come on. Your making the claim that the rules may have changed. Prove it.

I make the claim the rules haven't changed. My proof is that all of our classical laws can provide a working, predictive view of the universe up to a quantum scale of the big bang.

Checkmate.

>>2349572
Energy can't be created or destroyed, only transferred.

So where did it come from? If the rules haven't changed then what we know is wrong, if they have changed (as seems to be the case) then assuming that the rules were the same before energy was created are the same as they are now is obviously flawed and illogical

>>2349545
If you don't know about symmeteries, least actions, generators and nothers shit, you really aren't doing advanced physics.

Indeed energy is generated by time, this is why energy is only conserved when time is homogenious.

http://en.wikipedia.org/wiki/Homogeneity_(physics)
http://en.wikipedia.org/wiki/Symmetry_(physics)

Anymore questions?

>>2349572
>My proof is that all of our classical laws can provide a working, predictive view of the universe up to a quantum scale of the big bang.

So where did energy come from?

>>2349588
>Energy can't be created or destroyed, only transferred.

Another wrong assumption. Conservation of energy only occurs in systems with the homogenity of time.

"Homogeneity (in space) implies conservation of momentum; and homogeneity in time implies conservation of energy."

http://en.wikipedia.org/wiki/Homogeneity_(physics)

>>2349590
I will look into it, thanks. Never said I was doing advanced physics.

>>2349590
MIND = BLOWN

>>2349606
>Being homogeneous does not necessarily mean the equation will be true

Read your links next time brah

>>2349588
>>2349594
Uncertainty principle allows creation of inflaton field, which expands and decays into a sea of energy and particles. I know I fucking explained it earlier. Just because you have no fucking idea what that means or how it is allowable, it doesn't make you smarter by doubting it.

I'm not going to write it all down. Google is your friend.

>>2349620
See
>>2349435

>>2349618
That has nothing to do with the comment that he posted. In Lagrangian mechanics, you can show using Noethers theorem that conservation of Energy equal with the statement that said system is invariant under continuous transformations in time.

>>2349637
Again, see what I already said. Show me your proof of why you would consider a different set of beginning rules as correct. You already know my place.

>>2349640
So where did time come from? Using one thing that has no rational beginning to explains another is retarded

>>2349640
Ironically, the time invariance of energy has no relevance to OP's question

Absolutely NO relevance

You are tooting your own horn. Congratulations on understanding classical mechanics. Don't shove it into every hole you can find.

>>2349620
What uncertainty principal?

You, too, are talking out of your ass.

>>2349651
See
>>2349588

>>2349660
>provide explanation
>falls back on ignorance
>explain
>falls back on ignorance

If you don't get it, I can only do so much to try and teach you. I think it's official. I won.

Somewhat related.

Given the uncertainty principle we can either know where an atom is (i.e. see it) or know that it is travelling at a certain speed (i.e. sense its movement).

Does that mean that an atom which is being looked at cannot be moving. For, if it were moving then you would be able to both see it and sense its movement - breaking the premise.

Crazy thinking? proven thinking? new idea?

>>2349618
LMAO, you missed the whole fucking point.
And that comment is about dimensional homogeneity dumbshit, which is a different concept. That is not the sameshit as what not the homogenity of time.

>>2349659
You really don't believe the uncertainty principle is just about location and momentum, right?

. . . right?

>>2349612
No problem, if I'm here if you have any questions. Good Luck.

FYI: The origin and cause of most deep physics concepts some from symmetry arguments and all that shit

>>Energy can't be created or destroyed, only transferred.
Yes it can. That sentence is not valid in current physical theories, all of them involving special relativity. Even those that are dealt with classically are relativistic with a classical limit that doesn't kill all relativistic effects. Prime example: spin.

>Time would be the generator associated with energy
What the fuck am I reading
If anything, the Hamiltonian is the generator

>>2349680
The origin of energy

You really think it is because of a consequence of energy's uncertainty with time?

Do you even know the context of the relation? Do you not see the absurdity of defining something by itself?

>>2349666
>Get indisputably proved wrong
>I won

Typical behaviour of the stupid

>>2349672
Nice of you to sum up your post with your pic

>>2349705
They drag you down to their level then beat you with experience

>>2349690
To clarify, are you claiming the Hamiltonian is the total energy?

>>2349680 the uncertainty principle is just about location and momentum
Well it's certainly not about energy and time, for there is no time operator. There sure is a law involving time and energy being greater than 1 in a sense, but that's not the uncertainty principle anymore but describes the evolution of observables over time, i.e. how fast they can change. That's what is usually taught in beginners' QM lectures, but it's not a fundamental result. For uncertainty, you need noncommutative operators, <span class="math">p_i, x_j[/spoiler] or <span class="math">L_i, L_j[/spoiler] for example.

>>2349690
>>Energy can't be created or destroyed, only transferred.
>Yes it can. That sentence is not valid in current physical theories, all of them involving special relativity.
Where is this coming from? Energy is conserved in special relativity.

>>Time would be the generator associated with energy
>What the fuck am I reading
>If anything, the Hamiltonian is the generator
of time translations, you mean?

>>2349716
>To clarify, are you claiming the Hamiltonian is the total energy?
Er .. isn't it? You know, H = T + V ?

>>2349690
>If anything, the Hamiltonian is the generator

oHH....anit you the anon with the bIG Brains.
I see what you are saying. It is true in a basic linear algebra sort of way. H generates energy is the same thing as saying, enegry oberservation would generate the energy. Which is kinda true but kinda trivial.

Why time generates energy:
Take any system with homogenious time, apply symmetry -> energy is conserved

Take any system with inhomogenious time, apply symmetey -> energy is not conserved

Take a system with no time, apply symmetry -> system has no energy (not "0" energy, no energy)

Time generates the property we call energy.

>Doctor Feynman, what is energy?
>It's.. uhm... something.

>>2349720
>Where is this coming from?

Real Physics

>Energy is conserved in special relativity.

It is conserved for certain systems in special relativity, not all systems. It depends on how you define the system.

THIS JUST IN:
PHYSICS YOU LEARN IN HIGHSCHOOL IS JUST SHITTY APPROXIMATIONS THAT ONLY APPLY TO SPECIFIC SYSTEMS. THE "LAWS" YOU LEARN IN HIGHSCHOOL PHYSICS AREN'T "LAWS" IN GENERAL.

>>2349775
ooh, what was the name?

>>2349765
Actually, Feynman wrote a nice little article or paper about energy, pretty much sums up what it actually is.

>>2349777
http://www.leifiphysik.de/web_ph08_g8/lesestoff/01feynman/feynman_engl.htm

>>2349778
In what system is Energy not conserved? I'm tired as fuck but still up for a good read.

>>2349732

>>2349778
But if the physics is invariant under Poincare transformations, energy is conserved. I suppose you could have Lorentz symmetry but not time translation symmetry, but a statement like energy not being conserved in modern special-relativistic theories is quite bizarre.

>>2349732
>Basic linear algebra
Lie groups aren't particularly basic algeb....nah don't bother josef

>>2349790
thnx

>>2349799
true that just stop fucking trying, no one fucking cares

>>2349794
The only examples I know of in real life are either:
(1) In general relativity, it's hard to define what gravitational energy means.
(2) Systems where you ignore some part. The non-conserved energy actually flows to and from that part.

>>2349820
The other poster was referring to energy conservation in the context of special relativity, and so far I haven't heard of a single case where it was violated.

>>2349794
Fuckin tons

The basic example: any system whose L explicitly depends upon time. This implies if a potential changes with time, energy would not be conserved.

Real world examples would include things like a chaging magnetic field.

>>2349842
Ah, ok, you mean in the context of a subsystem where the energy balance is only considered within the subsystem itself. Yeah, but that's pretty obvious.

>>2349797
Poincare transformations, and Lorentz Symmetry already have the homogenity of time incoperated into them.

Do you even realize what the ideas the Poincare and Lorentz stuff represent? What they mean?

>>2349848
>>2349848

Yes, that is an example. However, it can happen in classically 'closed' systems as well.

It is possible to construct a 'classical closed' system that depends explicitly upon time.
Chapter 2.7 goes into it in great detail.

>>2349861
>Poincare transformations, and Lorentz Symmetry already have the homogenity of time incoperated into them.
Poincare yes, Lorentz no.

>Do you even realize what the ideas the Poincare and Lorentz stuff represent? What they mean?
Better than you apparently.

>>2349848
>took example and assumes it's the general case

>missed the point

Everything is a subsystem dumbshit.

>>2349887
>However, it can happen in classically 'closed' systems as well.
Sure, but those aren't real world examples.

>>2349906

Not everything is a subsystem, you genius. I have pretty much the freedom to construct a system that is closed off towards the rest of the world. Ever heard of the microcanonical ensemble?

>>2349919
Classical Field theory example:

Magnetize a peice of metal. Isolate is with other magnetic objects. The Potential terms of the system will be explicitly time dependent. I now have a closed system with a Lagraingian that varies with time.

The energy is not conserved.

>>2349948
>Not everything is a subsystem

Actually fundementally it is. Quantum Mechanics would like a word with you.

>>2349948
http://en.wikipedia.org/wiki/Quantum_tunnelling

>>2350002
I don't think you know what you are talking about. I have the freedom to construct a system in the sense of a microcanonical ensemble in e.g. statistical phyiscs. This is per definition isolated from everything else, with a fixed total energy.

>>2349989

>>2350012
You don't seem to know how tunneling works. By defining a compact area with a finite potential and tuning the "rest" of my world to be of infinite potential (infinite potential well anyone?), the tunneling probablity is exactly zero. I don't need to do WKB shit to calculate this ..

how about more interestingly

we believe when stuff is pact really tightly it wants to fallin on itself further aka black hole

yet everyone believes at the same time when everything was packed in really tight (i.e alot alot of stuff) it wanted to explode!

strange that we can believe that both are true ;D

>>2349989
Also, this argument is flawed in the sense of "breaking" energy conservation in a global matter. Your time dependent potentials are sure to exchange energy with an external bath - but at some point this becomes a moot discussion ..

>>2350016
Sorry to burst your bubble kid.

"Isolated systems can exchange neither matter nor energy with their surroundings, and as such are only theoretical and do not exist in reality (except, possibly, the entire universe)."

http://en.wikipedia.org/wiki/Isolated_system

The problem is you assume Stat physics provides fundemental laws of physics, that can be applied to everything. This is not the case.
Stat physics: "average properties" and "general appromixations" of a large system. It is "limited" in it range of validity, and only applicable to very specific systems.

>>2350051
Yeah, and the bath would interact with the shit it was in......ad infinimum.

Technically there is no such this as an isolated system. Qunatum Mechanics fucks up all that shit. However, in order to get physics done, you need the "concept of an isolated system" (since you can't possibly take into account every fucking thing in the universe everytime you make a calculation).

So you make "approximate isolated systems". When you refer to an "isolated system" in physics it is understood that is just a "very very very very very close approximation".

All physics ever done, by anyone, assumes this defintion of isolated systems. It is common knowledge. I guess I assumed too much of /sci/ once again. I really though yall already knew that basic shit.

>>2349820
isn't gravitation itself the manifestation or byproduct of energy proper to every non-massless particle?

>>2349478
but 3D is a illusion caused by you having two eyes.

>>2350269
we can move in, hear and touch these 3D. your point was...?

>>2350280
That proves what exactly?

You can be flat and still move, just because you can move forward and backwards in your prospective doesn't mean you really are moving backwards and forwards

>>2350280
>Implying you hear in more than one dimension

bump for a truly dismal thread