Where Does Energy Originate?

  • Thread starter Hypo
  • Start date
  • Tags
    Energy
In summary, the conversation discusses the laws of thermodynamics and conservation, which state that energy cannot be created or destroyed. The question of where energy comes from is then raised, with some participants suggesting the big bang theory as a possible explanation. However, it is acknowledged that the big bang theory does not provide an answer to the origin of energy. The conversation concludes with the realization that while we have many laws about energy, we still do not fully understand its origins.
  • #141
Whovian said:
With all due respect, we're not talking philosophy here; we're talking cosmology.
Where did you get the idea that I was talking philosophy and that everyone else here is talking cosmology? We are talking about Energy and where it comes from if I'm not mistaken? By the way, do you have any constructive take on the question at hand?
 
Space news on Phys.org
  • #142
Drakkith said:
I think I see what you are saying Mark. Consider my examples to mean that all this happens for NO reason. IE the rock is moved back up to it's starting position and the heat it created still exists, while the CO2 splits and combines back into gasoline yet there isn't enough energy to do so to all the molecules.

Well, the heat energy that the rock lost during the collision was regained and became kinetic energy, which gave it the ability to move upward, until gravity converted all of the kinetic energy back into potential energy. So, we could think of it like this:

total energy of system when rock is on ground = momentum the Earth received from the collision + heat energy

total energy while rock is moving upward = kinetic energy + potential energy

total energy while rock is at maximum height = potential energy

We could then separate the total system into two parts - the rock, and the environment. The rock has no energy on the ground, it's in a high entropy form (heat) in the surrounding area. While at the top, it's in a low entropy form (potential energy), and it's all in the rock. Since, due to the second law, low entropy systems evolve into high entropy ones (usually), we will see the rock falling more often then just randomly moving upward.

So, the point I'm trying to convey is this - if the reaction occurred one way, we know the total of all resultant forms of energy is equal to the total of all the forms of energy prior to the reaction. For the rock, we know that all of the above expressions are true. So, there was enough energy to get the rock to fall down. Therefore, there must be enough energy in the environment to get it back up, since all of the energy (kinetic) that it had when hitting the ground had to transferred int something else, no more, no less.

So, with the chemical reaction, we know that the energy needed for the reaction to occur one way must be the same amount needed for it occur the other way (if you record a chemical reaction on film, does playing it in reverse reveal any violation of the conservation of energy?). So, we know that the energy needed for it to occur is somewhere in the environment, either in the form of the resulting chemicals, heat, or whatever else you like. The key is just getting it back into the chemicals, so that they can do it in reverse. This is where the second law gets in your way, since the result of the reaction is a much higher entropy configuration, so getting it do anything is much more difficult.

Well, it wouldn't be for no reason. Since heat is just the non-mechanical transfer of energy due to a difference in temperature, we can imagine our rock regaining energy from the heat by having all of the excited air molecules (remember, temperature is just a measure of the average motion of the constituent particles) all simultaneously slamming into the rock, exciting the motion of its atoms, causing it to gain temperature, which may give it enough kinetic energy to rise up.

Once again, we see where the second law gets in the way - the chance of all of those particle simultaneously slamming into the rock is very, very small, so it won't happen very often.
 
  • #143
I think you are missing my point Mark. I'm saying that to create energy we would need to have one of my examples happen, where we see rocks teleporting or flying back to their starting positions for no reason. Same for the CO2.
 
  • #144
Drakkith said:
I think you are missing my point Mark. I'm saying that to create energy we would need to have one of my examples happen, where we see rocks teleporting or flying back to their starting positions for no reason. Same for the CO2.

I guess I am then. Are you saying that the rock spontaneously going up without first gaining energy (i.e. heat) constitutes a violation of the CoE? In that case you're right, I agree.
 
  • #145
Hypo said:
Okay... For he last 3 months I've been studying energy back to back with undergoing all the laws that supports it.

Two famous laws "Thermodynamics" + "Law of Conservation" both state that ENERGY CAN NOT BE CREATED OR DESTROYED, ok makes sense because so far everything on this universe follows it. But then I ask my self then where did it come from? Now philosophy is applied to this question to give a reasonable answer.

I do believe in those laws so far they've been the fundamental laws of physics. However, we use physics mostly to answer questions now the BIG question is left un answered where does energy come from?

Since now they believe in the BigBang"Universe from nothingness" then that violates the laws since energy can't come from nothingness.

The problem is caused by describing zero space as nothingness.

At t = 0, there was zero space – but (respecting the indestructibility of energy) zero space does not mean zero everything else ... indicating that energy (whatever it is) does not require dimensionality/space for its existence.
 
  • #146
Mark M said:
I guess I am then. Are you saying that the rock spontaneously going up without first gaining energy (i.e. heat) constitutes a violation of the CoE? In that case you're right, I agree.

Exactly!
 
  • #147
Perchie said:
The problem is caused by describing zero space as nothingness.

At t = 0, there was zero space – but (respecting the indestructibility of energy) zero space does not mean zero everything else ... indicating that energy (whatever it is) does not require dimensionality/space for its existence.

I'm not sure this is accurate. How can something exist if it has nowhere to occupy?
 
  • #148
Drakkith said:
What do you mean by saying the cosmos is comprised of stuff other than mass and energy?
The Univrse is 99.99% space by volume.
 
  • #149
Perchie said:
The problem is caused by describing zero space as nothingness.

At t = 0, there was zero space – but (respecting the indestructibility of energy) zero space does not mean zero everything else ... indicating that energy (whatever it is) does not require dimensionality/space for its existence.

Quantum mechanics forbids particles from being crammed into spaces smaller than their wavelength. Because Hawking's singularity theorems only use classical general relativity, it is assumed that whatever quantum theory of gravity is correct will prevent a big bang singularity. For example, LQG replaces the big bang with a 'bounce' type scenario. So, at no point was there 'zero space'.
 
  • #150
I thought all the matter and energy of the universe were contained in a singularity, and that the big bang was merely a sudden expansion of this singularity into space and time? The energy and mass was always there?

http://www.physlink.com/education/askexperts/ae649.cfm
 
  • #151
At t = 0, there was no matter, space or time ... only an adimensional pure 'energy' potentiality.
Dimensionality together with this energy potentiality, created space-time and eventually, matter.

Since there was no space-time at t = 0, there was no before or outside it ... and the universe existed as pure, adimensional energy.

To exist before or outside t = 0 is impossible because there was no matter to allow the existence of anything ... there was only the energy potentiality.

You could argue that from t = 0, there is numberedness/dimensionality - and it 'sprang' from the numberless, infinite, adimensional totality of the energy potentiality.
 
Last edited:
  • #152
Technically we don't know what happened at t=0, or if there even was a t=0.
 
  • #153
Drakkith said:
Technically we don't know what happened at t=0, or if there even was a t=0.

:approve:APPLAUSE...accolades...cheer...ROF

Even the TV science wizards like Michio Kaku have somewhat (but not entirely) backed off the notion that (if there was) a Big Bang initiated the phenomenon of existence.

Before something can change, before something can act or be acted upon, it must exist.

This is a rather simple axiom, intrinsically self-evident since any who might dissent must confess a belief in things that don't exist. Existence in the absence of change is possible but change in the absence of existence is not. The fact that existence is required in order for cause and effect to occur means change is derived from the phenomenon of being which, in turn, means existence is the source of cause and effect and not the result of it.

A cosmos finite in time or volume is quite simply illogical.
 
  • #154
Farahday said:
:approve:APPLAUSE...accolades...cheer...ROF

Even the TV science wizards like Michio Kaku have somewhat (but not entirely) backed off the notion that (if there was) a Big Bang initiated the phenomenon of existence.

And they're reputable sources because? Most of those shows turn out to be rubbish.

Before something can change, before something can act or be acted upon, it must exist.

This is a rather simple axiom, intrinsically self-evident

In physics, the only things we take to be self-evident are that we exist and the Universe exists. We can then experiment on the Universe to try to figure out how it works.

since any who might dissent must confess a belief in things that don't exist.

Please explain this in a little more detail.

Existence in the absence of change is possible but change in the absence of existence is not. The fact that existence is required in order for cause and effect to occur means change is derived from the phenomenon of being which, in turn, means existence is the source of cause and effect and not the result of it.

Correct, but what does this have to do with anything?

A cosmos finite in time or volume is quite simply illogical.

Then demonstrate so.

Anyway, your post seems to be philosophy, not physics. Please post in the appropriate forum.
 
  • #155
t = 0 is the divider between dimensionality and non-dimensionality - between the concrete and potentiality.

Our definition of 'existence' is currently confined to the realm of dimensionality.

Evidently, the universe existed without dimensionality - as an energy potentiality.

To deny this is to demonstrate the limitations on our current concept of existence.

If we can conceive that the existence of 'the potentiality' is possible without space-time, then the 'everything from nothing' conundrum is swept away.
 
Last edited:
  • #156
Perchie, do you have a reputable source for saying the universe existed without dimensionality? To my knowledge we simply don't know. Thanks.
 
  • #158
Drakkith said:
Perchie, do you have a reputable source for saying the universe existed without dimensionality?
Sorry, no - it's purely my personal opinion.
And I cannot imagine that it could ever be knowable.
It's about as conjectural as it gets - but that won't stop me thinking about it.
 
  • #159
Perchie said:
Sorry, no - it's purely my personal opinion.
And I cannot imagine that it could ever be knowable.
It's about as conjectural as it gets - but that won't stop me thinking about it.

Please stick to current mainstream science when posting here as per PF rules. Otherwise threads get bogged down with people who just post their opinions and no discussions of real science take place. If you don't know the current view on a subject you can ask about it, go look it up, etc.
 
  • #160
Drakkith said:
Please stick to current mainstream science when posting here as per PF rules. Otherwise threads get bogged down with people who just post their opinions and no discussions of real science take place. If you don't know the current view on a subject you can ask about it, go look it up, etc.
OK.
Is there a subforum for more conjectural discussion ?
 
  • #161
Perchie said:
OK.
Is there a subforum for more conjectural discussion ?

There is not. PF is strictly for currently accepted mainstream theories only.
 
  • #162
Farahday said:
Existence in the absence of change is possible but change in the absence of existence is not. The fact that existence is required in order for cause and effect to occur means change is derived from the phenomenon of being which, in turn, means existence is the source of cause and effect and not the result of it.

A cosmos finite in time or volume is quite simply illogical.

Spacetime exists and does not change. However, in the context of spacetime, one can talk about the "temporal change" of a particular spatial hypersurface in a particular foliation. Analogously, one can talk about the "southern change" of lines of constant latitude on the surface of Earth. "Causes" for this "change" then lie north of any given point. There is nothing north of the North Pole, so it exists "uncaused." This does not present any conceptual problems as long as you realize the fundamental object is the Earth as a whole, not the slices and "change" associated with your particular map of it.
 
  • #163
Energy can be both positive and negative. The positive energy of matter and motion exactly offsets the negative energy of gravitational attraction. We do not know this for sure, but there are impressive calculations which show this, and negative energy has been experimentally verified using Casmir plates. This is basically the zero-energy universe hypothesis. If the universe has a net energy of zero, then you do not need any energy at all to get everything you see. Hopefully this helps a bit :)
 
  • #164
Rational T said:
Energy can be both positive and negative. The positive energy of matter and motion exactly offsets the negative energy of gravitational attraction. We do not know this for sure, but there are impressive calculations which show this, and negative energy has been experimentally verified using Casmir plates. This is basically the zero-energy universe hypothesis. If the universe has a net energy of zero, then you do not need any energy at all to get everything you see. Hopefully this helps a bit :)

You're confounding two things here: (a) "negative energy" in "the negative energy of gravitational attraction," and (b) "negative energy" in the sense of violating an energy condition ( http://en.wikipedia.org/wiki/Energy_condition ). These are not the same. If they were the same, then energy conditions would be trivially violated in all cases where gravity operates, and would therefore be of no interest.

Your stuff about the total energy of the universe being zero is also not right; see our FAQ: https://www.physicsforums.com/showthread.php?t=506985
 
  • #165
bcrowell said:
You're confounding two things here: (a) "negative energy" in "the negative energy of gravitational attraction," and (b) "negative energy" in the sense of violating an energy condition ( http://en.wikipedia.org/wiki/Energy_condition ). These are not the same. If they were the same, then energy conditions would be trivially violated in all cases where gravity operates, and would therefore be of no interest.

Your stuff about the total energy of the universe being zero is also not right; see our FAQ: https://www.physicsforums.com/showthread.php?t=506985

Yes, certain things need to be changed to accommodate a zero-energy universe. This doesn't mean it's false.
 
  • #166
bcrowell said:
You're confounding two things here: (a) "negative energy" in "the negative energy of gravitational attraction," and (b) "negative energy" in the sense of violating an energy condition ( http://en.wikipedia.org/wiki/Energy_condition ). These are not the same. If they were the same, then energy conditions would be trivially violated in all cases where gravity operates, and would therefore be of no interest.

Your stuff about the total energy of the universe being zero is also not right; see our FAQ: https://www.physicsforums.com/showthread.php?t=506985

I've done much research on this subject. Stephen Hawking, Laurence Krauss, Neil DeGrasse Tyson, Edward Tryon and countless other esteemed physicists believe a zero-energy universe is plausible.
 
  • #167
Rational T said:
Yes, certain things need to be changed to accommodate a zero-energy universe. This doesn't mean it's false.

The idea may be right or wrong, but your explanation of it is definitely wrong.
 
  • #168
bcrowell said:
The idea may be right or wrong, but your explanation of it is definitely wrong.

Well, that's how it's commonly explained.

"Astrophysicists Alexei Filippenko at the University of California, Berkeley and Jay Pasachoff at Williams College explain gravity's negative energy by way of example in their essay, "A Universe From Nothing": "If you drop a ball from rest (defined to be a state of zero energy), it gains energy of motion (kinetic energy) as it falls. But this gain is exactly balanced by a larger negative gravitational energy as it comes closer to Earth’s center, so the sum of the two energies remains zero."" - http://www.lifeslittlemysteries.com/1224-total-energy-universe-zero.html
 
  • #169
Rational T said:
I've done much research on this subject. Stephen Hawking, Laurence Krauss, Neil DeGrasse Tyson, Edward Tryon and countless other esteemed physicists believe a zero-energy universe is plausible.

Rational T said:
Well, that's how it's commonly explained.

"Astrophysicists Alexei Filippenko at the University of California, Berkeley and Jay Pasachoff at Williams College explain gravity's negative energy by way of example in their essay, "A Universe From Nothing": "If you drop a ball from rest (defined to be a state of zero energy), it gains energy of motion (kinetic energy) as it falls. But this gain is exactly balanced by a larger negative gravitational energy as it comes closer to Earth’s center, so the sum of the two energies remains zero."" - http://www.lifeslittlemysteries.com/1224-total-energy-universe-zero.html

You've read some popularizations and then tried to apply them incorrectly. The Wikipedia article and FAQ entry linked to from #164 are both extensively referenced to professional-level sources such as graduate-level textbooks and peer-reviewed papers.
 
  • #170
Thread closed, as this is drifting into the realm of speculation.
 
Back
Top