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Author Topic: A question about dark energy?  (Read 1033 times)

Offline puppypower

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A question about dark energy?
« on: 25/12/2015 17:07:33 »
Dark energy is assumed to be responsible for the expansion of the universe. Since the expansion is causing a red shift and since a red shift lowers the energy potential of all the energy quanta that are red shifted, how does dark energy reduce the amount of regular energy; energy conservation?

In other words, if we started with energy of any given wavelength and then increase the wavelength, there is a decrease in energy potential, since longer wavelength quanta are weaker. If dark energy is red shifting all the energy in the universe, is dark energy a type of anti-energy to maintain energy conservation since regular energy is being destroyed in the sense of decreasing? 

Say I was start with no matter, and just energy. We have a zone of dark energy active, causing a red shift. Would dark energy act like anti-energy and suck the potential out of all the photons so they can red shift and define less total energy.


 

Offline evan_au

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Re: A question about dark energy?
« Reply #1 on: 25/12/2015 23:01:54 »
Quote from: puppypower
if we started with energy of any given wavelength and then increase the wavelength, there is a decrease in energy potential
We must always ask "from whose point of view?" or, equivalently "In whose frame of reference?".
  • From the frame of reference of a distant galaxy, which is moving away from the original star, the light does appear red-shifted, and the photons do have a lower energy.
  • However, from the frame of reference of the star which originally emitted the photon, it still has the wavelength and energy with which it was emitted. 
So has the energy potential decreased, or not decreased?

From a relativity viewpoint, the total energy of the universe has not changed, but different observers may disagree about how it is divided up.

Quote
Dark energy is assumed to be responsible for the expansion of the universe.
The nature of Dark Energy is a mystery in modern physics; it is thought that a scalar field could cause the observed effects.

A hypothetical particle nicknamed the "inflaton" has been suggested as the cause of the initial period of inflation in the early universe which we see reflected in the uniformity of the Cosmic Microwave Background Radiation, as well as the accelerated cosmic expansion which we see when looking back at least 6 billion light-years into space.

The Higgs particle was an early candidate for the inflaton, but there are many other candidates in the running. The winner is not expected to be identified by November 2016.

Unfortunately, without understanding the quantum states of this hypothetical particle, it is not possible to predict its future behavior, or the long-term future of the universe.
 

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Re: A question about dark energy?
« Reply #1 on: 25/12/2015 23:01:54 »

 

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