Sherlock Holmes and the Missing Energy

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth"

So if a photon has a certain energy when it leaves a star, and has less energy after it arrives, then that photon has lost energy. That lost energy goes somewhere, we just don't know where yet.

Perhaps pair production in the vacuum of space (quantum foam), where particles and their antiparticle equivalents appear and then annihilate each other could be involved. Light could interact with these particles as it travels through space. When light collides with something it loses some of its momentum resulting in a less energetic photon.

I think trying to understand the physics of space is an important field that I hope will be examined thoroughly in the future. How many dimensions does it have (4,10,11,26)?, does it bend?, is it a form of energy?, can it change to other forms of energy?, is it continuous? or is it made up of particles?, etc.

Here is a link that explains pair production.

Pair Production

Roger wrote: "Perhaps pair production in the vacuum of space (quantum foam), where particles and their antiparticle equivalents appear and then annihilate each other could be involved. Light could interact with these particles as it travels through space. When light collides with something it loses some of its momentum resulting in a less energetic photon."
There may be something like this going on, who knows? I don't know enough about quantum effects to comment.

Standard cosmology says that the radiation energy density decreases inversely to the 4th power of the expansion factor. This means that the total radiation energy decreases, because space volume increases with the 3rd power of the expansion factor.
At the same time, vacuum energy density remains constant, meaning the total vacuum energy increases by the 3rd power of the expansion factor (with the volume of space). This means that the total energy of the cosmos is on the increase, hence the observed accelerated expansion rate!

So, does it matter where a wee bit of radiation energy goes?

"There may be something like this going on, who knows? I don't know enough about quantum effects to comment."

I would imagine if I said the same thing about Relativity you would recommend I learn more about it (perhaps by visiting your website ;).

Yea, as electronics engineer I guess I should learn more about quanta... Not as nice and 'tangible' as relativity and cosmology though!

The results are. Just stay away from Particle Physics, that stuff gives me the Heebie-Jeebies. Quantum Mechanics and QED is solid though.

Doesn't it contribute to the momentum of the star/emitting object? Better yet, if you were on the other side of the star (outside the boundaries of the known universe) you would observe a blue shift- equal but negative in sign to the red shift seen from the other side.

If a 500[nm] laser pulse with a duration of 1[us] were emitted from a distant galaxy towards here, and we sense the same pulse at 1000[nm], for sure its duration would be 2[us]. The proportion of the stretching of wave-length due to Doppler Effect should be the same for the stretching of time duration of the pulse. Jaime Soto Figueroa Chile

Just a guess - as they say, "everything is relative." Every measurement depends on where you are and how you're moving relative to the emitting object. I suspect that when this is taken into account an apparent contradiction won't be.

The effect that Jorrie refers to is a different effect. It's true that stars moving away from us give off light that is redshifted, and stars moving in our direction is blue shifted.

The reshift we are talking about occurs as light travels through space itself. In other words, these stars are more redshifted then they should be. It's a different type of redshift that seems to come from traveling through space itself.

Roger's right - we can assume all objects to be stationary in space itself, while space expands, thus lowering the frequency of light as it travels. Movements through space do happen and cause redshifts and blueshifts. They are however small compared to cosmological redshifts at large distances. The energy got 'lost' in the cosmological redshift.

Quote (Jaime): "If a 500[nm] laser pulse with a duration of 1[us] were emitted from a distant galaxy towards here, and we sense the same pulse at 1000[nm], for sure its duration would be 2[us]."
This would surely be the case. But is the energy contained in the pulse the same? RF engineers, pse advise!

Consider the "area under the curve", I believe that you will find the energy is the same.

I agree. In the case of pulses, energy density might decrease, but total energy remains constant. For the total universe, radiation energy apparently does decrease - see my reply (#6220) to Roger's comment.

Quote: "Doesn't it contribute to the momentum of the star/emitting object?"
It surely contributes to the momenta of both emitter and absorber. The problem is it seems that it contributes less to the absorber than to the emitter.

Your trick of viewing from the 'other side' won't work – you'll still see redshift! Outside of our observable universe there is just more expanding space, we think, so you will be carried away from the emitter.

A lot of oil has been processed into foam then cut into small blocks for cell phone covers to keep them looking nice in the store shelf. Isnt that a wornderful use of a engery source that is such high demand. I worry they will stop making the baby diaper the hold fliulds so well will before they dry up the mess rivers and streams. :).