Conservation of energy across the universe

In summary: String theory is a proposal for a way to reconcile quantum mechanics and general relativity, which is needed because the two theories are incompatible. Theories of everything are hard! String theory is by no means the only game in town, but it's the best game we've got so far. It's not at all clear that string theory will ever be testable, but it's the only proposal we've got, and it's a nice proposal.In summary, conservation of energy is a law that states that the total amount of energy in a closed system stays constant over time. However, it is difficult to apply this law to the universe as a whole. The concept of circumstantial evidence does not apply to the validity of
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K. Doc Holiday
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Conservation of energy

Is the law of conservation of energy absolute?

If so, doesn't it follow that all the energy of the big bang came from somewhere? That the energy of our universe must predate the big bang?

Isn't that circumstantial evidence of the validity of string theory which presupposes there was a 10 dimensional universe which broke down into a 6 and a 4.

The implosion/ explosion of the inner 7 dimensions being the origin of our 4 and the event in question classically described as "Big Bang"?

Just curious. I had jury duty 2 weeks ago and I learned about circumstantial evidence and how it is enough to establish guilt beyond a reasonable doubt.

Isn't circumstantial evidence the reason scientists created dark energy? Since we can't see it or know anything about it directly?Doc
 
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K. Doc Holiday said:
Is the law of conservation of energy absolute?
If so, doesn't it follow that all the energy of the big bang came from somewhere? That the energy of our universe must predate the big bang?
There's no unambiguous way of defining all "the energy of our universe", which makes it hard to use conservation of energy for the universe as a whole. However, we can phrase the law more precisely, and then it works: Take a small volume of space. The total amount of energy contained in this volume will be what started out there, plus what flowed in, less what flowed out. This is the "differential form" of the law of conservation of energy described by Baez here: http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html

Isn't that circumstantial evidence of the validity of string theory which presupposes there was a 10 dimensional universe which broke down into a 6 and a 4.
No. There's no relationship at all here.
 
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1. What is conservation of energy?

The law of conservation of energy states that energy cannot be created or destroyed, it can only be transformed from one form to another. This means that the total amount of energy in a closed system remains constant over time.

2. How does conservation of energy apply to the universe?

Conservation of energy applies to the universe as a whole, meaning that the total amount of energy in the universe remains constant. While energy can be transformed and transferred within the universe, it cannot be created or destroyed.

3. How is energy conserved in the universe?

Energy is conserved in the universe through various processes such as nuclear fusion in stars, electromagnetic radiation, and gravitational interactions. These processes result in the transformation and transfer of energy, but the total amount of energy in the universe remains constant.

4. What evidence supports the conservation of energy in the universe?

One of the key pieces of evidence for conservation of energy in the universe is the cosmic microwave background radiation (CMB). This is a faint glow of radiation that permeates the entire universe and is considered the remnant of the Big Bang, which is when the universe was created. The CMB provides evidence that the total energy in the universe has remained constant since the beginning.

5. Are there any exceptions to the law of conservation of energy in the universe?

While the law of conservation of energy holds true in most cases, there are some exceptions at the quantum level. According to quantum mechanics, energy can fluctuate in a vacuum and particles can spontaneously appear and disappear, violating the conservation of energy. However, these fluctuations occur within a very short amount of time and do not affect the overall conservation of energy in the universe.

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