Expanding Universe and the Red Shift

[Melendwyr]

Melendwyr - You were asked to stop pretending to be knowledgable about things that you are pretty ignorant about.

And that request came from people who confirm what I've said and then insist that they've shown me to be wrong.

To say that "no one really knows" is outside of your knowledge and is irresponsible - someone might take you seriously. As it happens, some people think they've got some good ideas about how the lumpiness came to be.

'Thinking you've got some good ideas' and 'knowing' are quite different states. Given that this is one of the Big Problems science is attempting to understand, representing any of the many unconfirmed and usually currently unverifiable hypotheses on the matter as an explanation is irresponsible.

 

[ynot]

Your conveyor belt analogy isn't right. In order to see more lower spectrum (red) light, the star would have to emit more of it. Also, if the lower spectrum light traveled faster, it would appear disproportionately dimmer compared to the higher spectrum.

Why dimmer? Hmm...how do I explain this.

Ok you have two belts. One moving at rate X and the other moving at 2X. At the start of each, you have a guy who places a red photon on it at the rate of one per second. Now imagine you are at the end of each belt, what do you see?

The X belt's photons are coming of more densely packed than the 2X belt. Densely packed photons means more energy is striking your eye at any given moment, and therefore appears brighter. In order to appear just as bright as the X belt, the 2X belt guy would have to double his rate.

WARNING: NOT a cosmologist. I am but a mere chemist. I really don't know anything useful. I am willing to be corrected.

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Another thing to think about:

I plan on beating the rotating galaxy example to death, so bear with me.

Say we have two identical stars (sample spectum emitted, same size, etc) in the same galaxy that are both the same distance away from us. The only difference ... one rotate towards us and one rotates away. What would we expect to see?

In your theory, they would appear identical because they are both the same distance away.

In the Big Bang Theory, we would observe one red shifted and the other blue shifted.

We see the latter.

Not sure I can follow (or agree) with what you have said here. To simplify things, lets imagine that the galaxy is a flat disc and we draw two diametrically opposed dots on the outer edge of one surface of the disc. We then spin the disc on a fixed point and on a flat plane (edge on and stationary to our view-point). As the disc rotates, the disc overall would remain the same distance away but one dot would be moving away from our view-point while the other would be moving closer. Whether a particular dot was moving away or closer would depend on which half of the disc it was on as the disc spins in relation to our view point. As long as the spin was fast and large enough, the moving away could cause the red shift and the moving towards the blue (as in my theory)

If the spinning disc was then caused to move away from our view-point (as in an expanding universe), the moving away effect of half of the spinning motion, combined with the overall moving away motion of the disc, would speed-up the overall moving away motion of the dot that was on the moving away side of the spinning disc. In other words, the red shift effect would be increased.

Exactly the opposite effect however would occur to the other dot. The moving towards motion of the half the spinning motion would be slowed down by the speed of overall moving away motion of the disc. If the overall moving away motion of the disc was greater than the rotational speed of the disc, then no part of the spinning disc would be moving toward the observer. Surely this would make it harder for the blue shift to occur in an expanding universe that a relatively stationary one. That is, if it is the spinning motion of galaxies the causes blue shift.

Bit of a ramble - Hope it makes some sense

 

[ynot]

This thread isn't about Mel. Back to the topic at hand.

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That is the difference between theism and science. A scientist will come across a mystery and say, "I don't have enough information yet. Maybe we'll get it one day." A theist will say, "Wow. I don't have information yet. God must have done it."

I can make any piece of the jigsaw fit if I have a pair of sissors.

EDIT - Sorry - should read scissors of course.

The balloon is just an illustration. The concept is that 3D space is curved in a "higher" dimension. There are actually attempts underway to measure the curvature of space. (I don't know how, I know they are trying it.) Alot of this stuff is still in the hypothetical stage. We are just trying to understand the universe.

Starting to dance a bit far from the band for me.

Why? You can't let personal feelings dictate reality. Just because something is counter intuitive does not mean it isn't true. Quantum physics is mindbending stuff, but it is testable. Weird things exist. The end.

Sometimes I am sceptical that the tests may be a pair of sissors.

(scissors)

Well you'd have to have a way to observe "non-matter" before we go any further.

Is light, heat or radiation matter?

 

[c4ts]

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

According to you, if you filmed two simultaneous and synchronous actions, one in red light, and one in blue-white light, and they were equidistant from the camera, the red event would happen before the white.

You can test it, but you'll find it doesn't work that way.

 

[ynot]

According to you, if you filmed two simultaneous and synchronous actions, one in red light, and one in blue-white light, and they were equidistant from the camera, the red event would happen before the white.

You can test it, but you'll find it doesn't work that way.

Yes - This is essentially what I'm suggesting. Given the overall speed of light however, the effect would not be apparent (or perhaps even measurable) at close distance. In other words, immense distances would be required to see the effect.

 

[ynot]

According to you, if you filmed two simultaneous and synchronous actions, one in red light, and one in blue-white light, and they were equidistant from the camera, the red event would happen before the white.

You can test it, but you'll find it doesn't work that way.

To put it another way, if the film was projected on to a screen, the screen would need to be an immense distance away to see the effect. Or perhaps I mean that the images would have to be projected on to the from an immense distance away.

(on to the screen)

 

[PixyMisa]

Oh, really? If expansion leads to actual movement through space, how can you reconcile galaxies that are moving away faster than light with Relativity? That's what the expansion implies, after all.

Yes, that's what it implies.

But you cannot see them. You cannot measure them. No signal can pass from you to those distant galaxies, under any circumstances whatsoever.

So there is no observation that needs to be reconciled with Relativity.

 

[Melendwyr]

Yes, that's what it implies.

But you cannot see them. You cannot measure them. No signal can pass from you to those distant galaxies, under any circumstances whatsoever.

So there is no observation that needs to be reconciled with Relativity.

Except that it's not possible to accelerate things past the speed of light. If the galaxies are moving through space, instead of space increasing between them, then there's a whole lot of nasty problems. You have to start drawing odd conclusions about the nature of space-time, instead of accepting the much simpler explanation that space is expanding and those galaxies are remaining still.

It's possible to adopt the view that the Earth really is staying still while the rest of the solar system orbits around it, but it's ridiculously difficult and not very useful. Same deal.

 

[ynot]

Am I right in assuming that, if the universe is expanding uniformly in all directions, and it has no edge, that it is impossible to define a centre or start point of the expansion?

 

[PixyMisa]

We had one person claim that light could not be vibrating more slowly because it violated the laws of physics, and the sources brought up by others have refuted that. Those sources explicitly demonstrated how expanding space produces results consistent with the idea of "tired light".

The "Tired Light" hypothesis is a specific statement intended as a counter to the idea that the Universe is expanding. It says that the cosmological red shift is not due to relative movement, but due to the distance travelled by the light in a static Universe.

That's why SpaceFluffer said "you can't even get your pseudoscience correct". Your statement of the tired light hypothesis bears no relation to what the hypothesis actually says.

Please look at my link this time.

 

[c4ts]

To put it another way, if the film was projected on to a screen, the screen would need to be an immense distance away to see the effect. Or perhaps I mean that the images would have to be projected on to the from an immense distance away.

(on to the screen)

Why? Are you suggesting that light is not only slower, but it decellerates?

 

[PixyMisa]

Except that it's not possible to accelerate things past the speed of light. If the galaxies are moving through space, instead of space increasing between them, then there's a whole lot of nasty problems.

Sure.

But they're not.

Now this is why I made my other comment - that I'm not married to this description. There are reasons not to speak of movement in this situation, or to qualify the term, but that's not what you're addressing.

It's possible to adopt the view that the Earth really is staying still while the rest of the solar system orbits around it, but it's ridiculously difficult and not very useful. Same deal.

What problems arise when you treat those distant galaxies as actually moving away from us?

If the relative motion is less than the speed of light, the red shift is precisely what it should be. Time dilation is what it should be.

If the relative motion is greater than the speed of light, you can't see them.

Where are those nasty problems?

 

[Melendwyr]

If the relative motion is greater than the speed of light, you can't see them.

How would you get two things moving away from each other, from their own perspectives, faster than the speed of light?

 

[ynot]

Why? Are you suggesting that light is not only slower, but it decellerates?

No - I am suggesting that different parts of the light spectrum might travel at different speeds. Red faster than blue.

 

[chipmunk stew]

Sometimes I am sceptical that the tests may be a pair of sissors.

(scissors)

And sometimes, scientists being as human as anyone else (although some may argue that point), this is true. However, one thing to remember is that scientists as a group are an insecure lot in the sense that they are never quite sure their methods are not flawed in some way and so they try to be very fastidious in their work. They also like finding flaws in other people's work. Look at how quickly the flaws in Whatsizname's study on stem cells was exposed (someone help me out here).

So, typically, when consensus forms around a particular topic in the scientific community, it happens not by cursory support of ideas that sound nifty or because it provides a convenient basis for a pet idea, but rather by begrudging and reluctant admission that they can't find any flaws. Only then is it considered a nifty idea.

Is light, heat or radiation matter?

Yes. In the technical sense, if not the vernacular. Remember: E=MC^2

 

[Melendwyr]

Your statement of the tired light hypothesis bears no relation to what the hypothesis actually says.

Tired light models invoke a gradual energy loss by photons as they travel through the cosmos to produce the redshift-distance law.

With expanding space, the longer photons travel, the more space there is between their vibrational nodes. Therefore they have less energy than they did when they were originally released.

If you invoke Tired Light to explain the observations, you don't get anywhere. If you invoke the expansion of space, one of the consequences of that is that photons will gradually lose their energy as they travel.

What objection do you have with this reasoning?

 

[chipmunk stew]

Am I right in assuming that, if the universe is expanding uniformly in all directions, and it has no edge, that it is impossible to define a centre or start point of the expansion?

Yes, that can be extrapolated from the idea.

 

[ynot]

And sometimes, scientists being as human as anyone else (although some may argue that point), this is true. However, one thing to remember is that scientists as a group are an insecure lot in the sense that they are never quite sure their methods are not flawed in some way and so they try to be very fastidious in their work. They also like finding flaws in other people's work. Look at how quickly the flaws in Whatsizname's study on stem cells was exposed (someone help me out here).

So, typically, when consensus forms around a particular topic in the scientific community, it happens not by cursory support of ideas that sound nifty or because it provides a convenient basis for a pet idea, but rather by begrudging and reluctant admission that they can't find any flaws. Only then is it considered a nifty idea

Nice if this is so, but I can’t help wondering if there's not sometimes a tad of an "Emperors New Clothes” thing happening as well.

Yes. In the technical sense, if not the vernacular. Remember: E=MC^2

I realise I will shot at dawn for this (if not earlier), but - What if E doesn't = MC^2

 

[chipmunk stew]

I realise I will shot at dawn for this (if not earlier), but - What if E doesn't = MC^2

Then the Bomb was a mass hallucination.

 

[ynot]

Then the Bomb was a mass hallucination.

Don't now enough about the Bomb (or E=MC^2) to debate it. Just being a cynical stirrer