In transit gravitational redshift

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jim</i>
<br />
Doppler redshift is measured in velocity units. <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">


Are you aware that there are several different types of Doppler effects due to motion? One is the type in which wavelengths are either physically stretched out in space or shriveled up, due an emitter moving relative to a medium, and another type is one in which a moving observer perceives a normal wavelength as being shorter or longer than normal when the observer is moving relative to the medium? In the first case the shifts occur near the emitter, and in the second case the shifts occur near the observer. This is one reason why, if a star’s motion toward or away from the earth changes, we won’t see the shift changes for years, but when the earth’s motion toward or away from the star changes, we’ll see the sift immediately.

According the theory light is propagating like a field or like particles. In my view we don't even know what a field is.

The duality I see already as a problem. What is gravity. Not yet heard a good answer.

These things have to do with understanding redshift I think. What do you think?

Could you explain me what an EM or other field is without using a formule. The formules are okay. We are used to them. But I have never seen a really good description of a field. And for me duality is a real problem as well.

What are we doing here?


Ed

Hi David, Good point-there are a lot of ways redshift are generated. The gravity induced redshift is of interest too and it would be good to classify the redshift.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by n/a</i>
<br />In my view we don't even know what a field is.Ed
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I don’t know about everyone else, but I think we have to consider a field to be some kind of “force field”, with the word “field” being sort of like saying an “area” of space that surrounds bodies, with some kind of “force” contained in that “area” of space. We have the three major “big” fields, such as gravity, electric, and magnet, and we have some tiny little fields that are inside atoms and that surround particles.

This is certainly not a complete definition, and fields still seem to be very mysterious to me. I think that so far, about all we can do to describe fields is to describe the effects they have on light, on particles, and on larger masses, and to try to describe their size, extent, and strength at different points within them.

Is a field a kind of structure? Not a physical structure like a star but still something with real properties.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jim</i>
<br />Is a field a kind of structure? Not a physical structure like a star but still something with real properties.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

About all I know about what a field “is”, is when I try to push the North and South poles of two magnets together. It feels like there is some kind of spongy material between the magnets. But when I look in between the magnets, I see nothing. When I reach in to grab the sponge, I feel nothing. When I put two pieces of wood together, there is no spongy feeling in the space between them. Only the magnets have the invisible, untouchable sponge between them. That’s mysterious.