The way light travels.

[Theninjagecko]

Am I right in thinking as light is a wave-particle, it travels through space by causing a "ripple" wave in the ether? just as or similar to sounds carried through the air?.

[themos]

Except there's no ether. Light is like sound only insofar it exhibits wave properties (interference, diffraction, dispersion).

[kniclander]

and light can "travel" in a vacuum but sound can't

[George Jones]

Light carries energy and momentum, so, according to general relativity, light waves do cause ripples in spacetime.

[acey]

But "ripples in spacetime" are gravitational waves, not electromagnetic ones.

In the early days of quantum theory there were attempts to explain wave-particle dualism by supposing that there were particles riding on waves; a later version of this was Bohm's pilot wave theory:

Pilot wave - Wikipedia, the free encyclopedia

As the Wikipedia article says, "The de Broglie-Bohm theory is now considered by some to be a valid challenge to the prevailing orthodoxy of the Copenhagen Interpretation, but it remains controversial."

In the Copenhagen Interpretation you've got things that exhibit wave-like or particle-like properties under particular circumstances, but they aren't one thing or the other, and there isn't a physical model for the waves (i.e. something that is vibrating).

So light isn't considered a vibration of anything.

[skye at night]

I still get a headache thinking about that 'theorem' about enclosing light inside a mirror lined box..

Is the light still there and does it bounce around there forever or is it dark inside?

Ouuuch!!!!!!!

Steve

[George Jones]

I still get a headache thinking about that 'theorem' about enclosing light inside a mirror lined box..

Is the light still there and does it bounce around there forever or is it dark inside?

Ouuuch!!!!!!!

Steve

Suppoose that two equal energy photons are released in opposite directions from the centre of a box that is a perfect cube. If the box is perfectly reflecting on the inside and perfectly non-reflecting on the outside, the box is dark form the outside. If, however, the box is put on a scale, the box is found to weigh more than when no photons are bouncing around inside!

[skye at night]

Stop IT!!!!!

Pills Please....

S

[steve_bham]

this might help:

Wave-particle duality

Wave?particle duality - Wikipedia, the free encyclopedia

[ollypenrice]

Richard Feynman's QED is a brilliant short account of how some of this works. He talks of probablilty waves. More pills all round.

Olly

[G4YVM]

Surely the photons in the box would dissapear as they turned into heat energy on the surfaces?

Unless the space goat ate them first.

David

[acey]

Not if the surfaces are "perfectly reflective".

Which they can never really be, of course.

So yes, the photons end up turning into heat - i.e. infra-red photons.

[badgerchap]

I understood everything up until the part about space goats.

[vhbelvadi]

I understood everything up until the part about space goats.

Doesn't that mean 'nearly everything'?

[badgerchap]

Yes, it does, but the space goats really threw me, as I wasn't expecting any space goats. Of course, there is a sea goat....

[AstroTiger]

Is it not correct that light exhibits properties of both particles and waves?

An intruiging concept, what is light.

what is time.

The big bang, black holes

in the absense of doing any proper astronomy i have spent much of my time reading about the big bang, as well as particle physics.

These concepts are like studying yoga, one needs to clear their minds i think before going there.

That said, i think Brian cox's book called what does E=MC2 mean is an excellent text to help here.

i am gibbering on again, see what 24 hours of trying to figure out dark matter does to you?

I need the pink ones i think!!!