The law of conservation of energy is wrong?

In summary, according to this conversation, the concept of energy in the universe is confusing and there is a mistake in the formula used to calculate it.
  • #1
nibbel11
36
2
e few days ago i talked with my teacher about the energy in the universe being constant. but we were completely confused when we came to the concept of:
"because of the universe expansion everything moves away from each other. and the same goes for the wavelenghts in light. because of the way electro-magnetic energy is being calculated. the energy increases with the wavelenght but isn't converted in anything."
is this right or not
if not where was our mistake.
 
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  • #2
what is even the formula of the enrgy of a phonton
E=hλ
or
E=hf
 
  • #3
Longer wavelength is lower energy.
 
  • #4
nibbel11 said:
e few days ago i talked with my teacher about the energy in the universe being constant.
One problem with saying that the amount of energy in the universe is the same from one instant in time to the next is with defining the notion of one instant in time.

In classical Newtonian mechanics the notion of "at the same time" is taken for granted and conservation of energy works. In special relativity, the notion of "at the same time" depends on the coordinate system you choose but as long as you choose an inertial frame of reference, conservation of energy still works. But with general relativity and curved space time, there is no such thing as a globally inertial reference frame. The notion of "at the same" time becomes a matter of pure convention. Locally one can choose to use an inertial frame so that locally, conservation of energy still works. But globally, it does not.

This in addition to the problem with even properly defining "energy" at cosmic scales.
 
  • #5
jbriggs444 said:
,, instant in time to the next is with defining the notion of one instant in time...
Well conventionally 'seconds' which can be measured by atomic clocks,
Ideally though we need to know if there is a quantized Planck time, either theoretically or in fact.
I won't be placing a bet on it.
 
  • #6
rootone said:
Well conventionally 'seconds' which can be measured by atomic clocks,
Ideally though we need to know if there is a quantized Plank time, either theoretically or in fact.
I won't be placing a bet on it.
Simultaneity has nothing to do with units of time.
 
  • #7
jbriggs444 said:
Simultaneity has nothing to do with units of time.
Fair enough, does that imply that in GR, simultaneity is not defined?
 
  • #8
rootone said:
Fair enough, does that imply that in GR, simultaneity is not defined?
Yes
 
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  • #9
nibbel11 said:
the energy increases with the wavelenght
The energy decreases with wavelength. But this still has the same problem. In fact, it is accepted that the radiation density of the universe has decreased more rapidly than the matter density of the universe because of this effect. Thermal energy is also reduced.
General relativity complicates things, but I think if you treat the universe as relatively smooth (using a fluid approximation), it is just a matter of defining an appropriate gravitational potential energy which accounts for the loss in radiation and thermal energy. Maybe this sounds like cheating, but the point is that if you contract the universe, you should be able to get back all the radiation energy that you "lost" by expanding the universe.
 
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  • #10
jbriggs444 said:
Yes
Yes too, but buses mostly do turn on time though (within acceptable limits of uncertainty)
 
  • #11
nibbel11 said:
what is even the formula of the enrgy of a phonton
E=hλ
or
E=hf
Check your units, E=hλ doesn't give the correct units for energy.
 
  • #12
rootone said:
Yes too, but buses mostly do turn on time though (within acceptable limits of uncertainty)
Indeed. The fact that GR does not prescribe a particular simultaneity convention does not preclude us from picking one that works locally.
 
  • #13
thanks everyone that helped a lot
:dademyday:
 

1. Is the law of conservation of energy really wrong?

No, the law of conservation of energy is a fundamental principle in physics that states that energy cannot be created or destroyed, only converted from one form to another. It has been extensively tested and verified through experiments and observations.

2. What evidence supports the idea that the law of conservation of energy is wrong?

There is no evidence that supports the idea that the law of conservation of energy is wrong. The law has been consistently supported by numerous experiments and is a fundamental principle in many areas of physics.

3. Can you give an example of a phenomenon that violates the law of conservation of energy?

No, there is no known phenomenon that violates the law of conservation of energy. In cases where it may seem like energy is being created or destroyed, there is often a conversion of energy from one form to another that can be explained by this law.

4. Are there any exceptions to the law of conservation of energy?

The law of conservation of energy is a universal principle and has no known exceptions. It applies to all physical systems, from the smallest particles to the entire universe.

5. Why do some people believe that the law of conservation of energy is wrong?

Some people may misunderstand or misinterpret the law of conservation of energy, leading to the belief that it is wrong. Others may propose alternative theories that attempt to explain certain phenomena, but these theories must still adhere to the fundamental principle of energy conservation.

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