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Posted

is the total enrgy in the universe constant,or a  variable?if it is a constant,exactly how much is there and where did it come from?is it zero?if it varies,then waht makes it to vary?if it is zero,and we assume that the energy of universe is constant,at the time of big bang,the energy was zero,so what prompted big bang.

 

 

 

 

sorry,i dont know much about theoritical physics.after all,i'm just a 9th grader!

 

 

Posted (edited)

is the total enrgy in the universe constant,or a variable?if it is a constant,exactly how much is there and where did it come from?is it zero?if it varies,then waht makes it to vary?if it is zero,and we assume that the energy of universe is constant,at the time of big bang,the energy was zero,so what prompted big bang.

 

 

 

 

sorry,i dont know much about theoritical physics.after all,i'm just a 9th grader!

 

energy is neither created nor destroyed

so it does not very

so it is constant

 

is it zero?

why would you think it's zero?

how much total energy? a modern physicist would give just about anything to know this. another one is total mass.

what prompted big bang? see above

and before you ask

what was before the big bang.

were not sure there was a before.

Edited by dragonstar57
Posted

Untill now known knowege.

 

Total Energy = Dark Energy + Dark Matter mass(corresponding matter mass) * C^2 + matter mass * C^2

 

I don't know Dark Matter mass fellow E=m*C^2 law.

This mass m means m1 or m2 from this equation, F=G m1 m2 / r^2.

Dark Enegy is not cleary defined yet.

If the multiuniverse was existence, total energy would be zero.

Posted

energy is neither created nor destroyed

so it does not very

so it is constant

 

 

why would you think it's zero?

how much total energy? a modern physicist would give just about anything to know this. another one is total mass.

what prompted big bang? see above

and before you ask

what was before the big bang.

were not sure there was a before.

 

 

Krauss gave a lecture where he said that if you treat mass as positive energy and gravity as negative energy they would cancell each other out and the net energy of the universe would be zero.

 

He also said the if you take a region of space and remove all particles from it so that there is nothing left, NOTHING left then what you see on the micro scale is particles breifly appearing and disappearing again and so nothing isn't nothing it is something. Therefore, he said, the universe could come from nothing.

 

Two things strike me with this

 

1) the nothing before TBB and the nothing after TBB are two different nothings, they aren't comparable

 

and

 

2) if the universe did come from nothing why is it finite, why does it have finite mass and energy if that mass and energy came from nothing?

 

getting back to the OP and dragonstar57's answer; was energy created during TBB or did it exist before TBB if so where did it exist?

Posted

We don't know the size of the universe, not even if it is finite or infinite. The observable universe is finite due to the expansion. As for the total energy, I'm usually much more concerned with changes in energy. However, if the gravitational potential measured with zero at infinite distance equals the mass-energy of the universe, that would be quite the coincidence and I would consider that strong proof that the total energy is indeed zero.

Posted (edited)

We don't know the size of the universe, not even if it is finite or infinite. The observable universe is finite due to the expansion. As for the total energy, I'm usually much more concerned with changes in energy. However, if the gravitational potential measured with zero at infinite distance equals the mass-energy of the universe, that would be quite the coincidence and I would consider that strong proof that the total energy is indeed zero.

but it can't be zero (proves it by piking up a book and doping it again).

 

Untill now known knowege.

 

Total Energy = Dark Energy + Dark Matter mass(corresponding matter mass) * C^2 + matter mass * C^2

 

I don't know Dark Matter mass fellow E=m*C^2 law.

This mass m means m1 or m2 from this equation, F=G m1 m2 / r^2.

Dark Enegy is not cleary defined yet.

If the multiuniverse was existence, total energy would be zero.

i think that dark matter is just matter that does not emit em radiation

Edited by dragonstar57
Posted

i think that dark matter is just matter that does not emit em radiation

 

 

We don't know the gravitational property of the Dark Matter.

And , the pressure which it can do the fusion reaction is not unknown.

 

Dark Matter mass has the same effect as the mormal matter on the fusion reaction.

Any good data?

Posted
but it can't be zero (proves it by piking up a book and doping it again).

 

How does that prove it can't be zero? All you can see in that example is the changes in energy (from chemical energy to gravitational potential energy to kinetic energy to thermal energy), all with energy being conserved, but from that example you can't say what is the total energy.

Posted (edited)

but there IS energy in that example

so therefore unless your talking about the possibly nonexistent negative energy (i have never heard any announcements of its discovery) than the total energy can't be zero

Edited by dragonstar57
Posted (edited)

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

 

According to classical mechanics, between two or more masses (or other forms of energy-momentum) a gravitational potential energy exists, from which the gravitational field energy density can be calculated. Conservation of energy requires that this gravitational field energy is always negative.[1]

 

 

http://en.wikipedia.org/wiki/Energy_density#Energy_density_of_electric_and_magnetic_fields

 

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

Edited by granpa
Posted

If you subscribe to the idea that the big bang contained the entire contents of energy/mass that exist as "the universe," then the total amount of mass-energy in that would seem to be finite. However, stars are converting mass into energy so if there's no process converting energy to mass, the amount of energy would be increasing while the mass of matter would be decreasing.

 

Finally, what happens to light and other radiation as it travels beyond the most distant matter? Does it continue linearly indefinitely or does it curve back around in the direction of some other mass? Even if it continues endlessly outward, it presumably cannot "leave the universe" since its movement constitutes one front in the universe's expansion. So the universe cannot lose energy in that sense.

Posted

If you subscribe to the idea that the big bang contained the entire contents of energy/mass that exist as "the universe," then the total amount of mass-energy in that would seem to be finite. However, stars are converting mass into energy so if there's no process converting energy to mass, the amount of energy would be increasing while the mass of matter would be decreasing.

 

"Mass" is not converted into "energy." Matter is converted into electromagnetic radiation. Mass and energy are the same thing, and they are a property of stuff, not the stuff itself. (e.g. Light is not energy. Light has energy.) The amount of energy in a closed system does not increase or decrease. (But it is dependent on frame of reference.)

 

Finally, what happens to light and other radiation as it travels beyond the most distant matter? Does it continue linearly indefinitely or does it curve back around in the direction of some other mass? Even if it continues endlessly outward, it presumably cannot "leave the universe" since its movement constitutes one front in the universe's expansion. So the universe cannot lose energy in that sense.

 

It sounds like you're imagining the expansion of the universe as an ordinary explosion moving outwards in a sphere, but that isn't accurate. Expansion is not motion through space, but expansion of space. The shape of the universe would not be an ordinary 3D shape like a sphere, and may well be infinite.

Posted

"Mass" is not converted into "energy." Matter is converted into electromagnetic radiation. Mass and energy are the same thing, and they are a property of stuff, not the stuff itself. (e.g. Light is not energy. Light has energy.) The amount of energy in a closed system does not increase or decrease. (But it is dependent on frame of reference.)

I agree that mass is a property of matter; but I don't get how you can say that light is a carrier of energy when it has no mass. How can you call something without mass a substance? Saying that there is something in light besides pure energy implies that there is a potentially "lighter" medium for energy that could transfer energy faster than light. My understanding is that light sets the maximum speed for energy-transfer because it has no mass and therefore accelerates instantaneously to C.

 

It sounds like you're imagining the expansion of the universe as an ordinary explosion moving outwards in a sphere, but that isn't accurate. Expansion is not motion through space, but expansion of space. The shape of the universe would not be an ordinary 3D shape like a sphere, and may well be infinite.

What does it matter how you model universal expansion in terms of this thread's issue of whether energy is increasing, decreasing, or remaining constant? The only thing that matters is whether radiation can ever "escape" the universe, which I am presuming it can't. Where would it go that wouldn't be an extension of the universe it originated from?

 

But to respond to your point that expansion is not motion through space but expansion of space, I've heard people say that many times but I don't think people can generally conceptualize what it means for space to expand without thinking of space as a substance, which is a flawed conception, imo. Space/time is nothing more than motion-relations between energized forms. It is not a container that exists separately from those forms, imo. Saying that it expands refers to systematic changes in multiple sets of "spatial" relations, imo. I get the feeling that many people tend to conceptualize is as a medium/substance when it is described as a "fabric" that is expanding.

 

 

 

Posted

I agree that mass is a property of matter; but I don't get how you can say that light is a carrier of energy when it has no mass. How can you call something without mass a substance?

 

"Substance?" A photon is something that exists, if that's what you mean. A property of a photon is its energy in a given reference frame. And since energy and "relativistic mass" are the same thing, a photon also contributes to the mass of a system, e.g. a perfectly mirrored boxed with photons bouncing around in it is heavier than the same box with darkness inside.

 

Saying that there is something in light besides pure energy implies that there is a potentially "lighter" medium for energy that could transfer energy faster than light.

 

Why would it imply that? And again, there is no such thing as "pure energy." Energy is a property.

 

My understanding is that light sets the maximum speed for energy-transfer because it has no mass and therefore accelerates instantaneously to C.

 

More or less. It has no rest mass, and it only exists at C (i.e. does not "accelerate"), but yes.

 

What does it matter how you model universal expansion in terms of this thread's issue of whether energy is increasing, decreasing, or remaining constant?

 

It doesn't, as far as I can see.

 

But to respond to your point that expansion is not motion through space but expansion of space, I've heard people say that many times but I don't think people can generally conceptualize what it means for space to expand without thinking of space as a substance, which is a flawed conception, imo. Space/time is nothing more than motion-relations between energized forms. It is not a container that exists separately from those forms, imo. Saying that it expands refers to systematic changes in multiple sets of "spatial" relations, imo. I get the feeling that many people tend to conceptualize is as a medium/substance when it is described as a "fabric" that is expanding.

 

Yes, it can be difficult to conceptualize. The point was that it isn't motion through space, like an expanding sphere with a wave front and a center, etc.

Posted

light is made of electric and magnetic fields

fields have an energy desity which is proportional to the square of the field intensity

Posted

"Substance?" A photon is something that exists, if that's what you mean. A property of a photon is its energy in a given reference frame. And since energy and "relativistic mass" are the same thing, a photon also contributes to the mass of a system, e.g. a perfectly mirrored boxed with photons bouncing around in it is heavier than the same box with darkness inside.

That suggests to me that mass/inertia could be a function of energetic motion, the way a gyroscope exhibits resistance to directional-changes more when its wheels are spinning. However, I don't see what else constitutes light besides the energy relations between the source and recipient of emissions. Energy seems to simply jump from one electron-cloud to the next at the speed of light without anything else involved.

 

 

Why would it imply that? And again, there is no such thing as "pure energy." Energy is a property.
What implied it was that you claimed that energy was a property of light independently of the emission source and receptor. Light seems, imo, to be purely an interaction between electromagnetism and gravitation. If it had some other medium than "spacetime," it would not exist as the speed-limit for everything with mass, right?

 

  • 2 weeks later...
Posted

If you include darke energy, which aparently is what most of the universe is made up of, then your answer could be 72-73% (the predicted percentage of dark energy out of all matterenergy in the universe) buuutt,, if you include that matter itself is a form of energy, then you have 100% of the matterenergy of the universe including dark energy, dark matter, and regular ordinary matter and energy. This amount is unavailable at this time.... sorry. ask again when we have become a type 3 civilization.

Posted

My belief is that the energy of the universe must either be zero or infinite. If energy was created during TBB (ie. there was no energy before TBB) then why was a finite amount created? If energy existed before TBB, again, why was there a finite amount?

 

If new energy was continuously being created, where would that be taking place do you think?

Posted

Hi everybody,

 

The space is infinite.

 

Matter is one form of energy.

 

Antimatter is another form of energy.

 

When matter and antimatter meet they are annihilated. Annihilation does not mean that energy becomes zero. It only means that when matter and antimatter meet they are converted back to energy.

 

So can we not say that, the total energy of the universe remains constant and is not zero?

 

Thanks.

Posted

I don't think it is continuously being created, I'm just wondering why there would be a finite amount.

If it was no longer being created, wouldn't that mean it was finite?

Posted

not if an infinite amount was created

Isn't it oxymoronic to say "an infinite amount was created" in the past-perfect tense? If it was created then it stopped at some point, right? And if it stopped than it is no longer producing more.

 

BTW, did the forum guidelines happen to tell you that your username had to be "between 3 and 29 characters long" and you just followed the directions? If so, that is very funny. Even if that's not why you did it, it's still funny actually.

 

 

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