Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: shmengie on 10/04/2008 08:10:04
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Last night while watching the "What We Don't Know" series the second time, I got frustrated that every cosmological video magazine iterates the redshift in light is caused by an increasingly expanding universe. I object!
I postulate the redshift is caused by all gravity** wells the light wave must pass between the source of the light and it's destination (Earth). Each time it is bent, even slightly, energy will be lost down shifting it toward the red. The further the light originates from us, the more gravity wells it will pass in it's trek across the universe to reach observation.
Therefor, the further the light originates, the more gravity wells (bends) it will encounter and undoubtedly be shifted toward the red. It may not mean the universe is speeding up in expansion, but whomever wishes to believe that, is neglecting to count the number galaxies/supermassive black holes with which the corpuscle/photon/electromagnetic wave must pass en route.
** http://en.wikipedia.org/wiki/Gravitational_redshift
BTW: I'm new to this forum, hope ya'll enjoy my warped sense of humor, if it ever appears. [:o]
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1.You can't refute the existence of the 'red shift' effect due to motion. You can set up lab experiments which can produce and measure it at extremely low velocities.
2.The Big Bang theory has the support of the Cosmic Background Radiation.
3. The Steady State / Infinite Universe idea is hard to sustain.
4. A finite Universe must either be expanding, contracting or 'just happen' to be on the cusp between the two; gravity must be at work, pulling everything inwards.
5. The effects of General Relativity have been measured (you can do this in the Lab, too) and the shift due to the masses would not be enough.
6. You would have to support your argument with a lot of Quantitative evidence and calculation. Qualitative argument is not enough for such a radical idea.
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Aditionally, as far as I know for the definition of a gravity well, it would be that if the light goes in and then comes out it will have the same energy. i.e. it will be blue shifted as it enters the well and red shifted in coming out.
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Aditionally, as far as I know for the definition of a gravity well, it would be that if the light goes in and then comes out it will have the same energy. i.e. it will be blue shifted as it enters the well and red shifted in coming out.
What about spacecraft that use planets to slingshot themselves faster? Isn't that the same as passing through a gravity well?
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It is passing through a moving gravity well. In the centre of mass frame of the probe and the spacecraft the spacecraft leaves at the same speed as it entered, but in the frame of the rest of the solar system the spacecraft could have speeded up.
If the probe approaches the planet moving in the opposite direction to the planet with a speed Vs and then came back out going in about the same direction as the planet. If the planet has a speed Vp
The craft's original speed relative to the planet will be Vs+Vp
so it will leave in the same direction as the planet with a speed of Vs+Vp
relative to the rest of the solar system it will now have a speed of Vs+2Vp
Although in most cases the effect won't be this strong due to the orbital dynamics involved.
I guess something similar could happen to light, but it is going to be a tiny effect because the light will not change direction very much, and the speeds involved are tiny compared with the speed of light.
The other explanation of red shift which is different to the stretching thing, is that during the big bang everything was very close together so you were in a huge gravitational potential well and the light has been climbing out of it, and so redshifting, ever since
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1.You can't refute the existence of the 'red shift' effect due to motion. You can set up lab experiments which can produce and measure it at extremely low velocities.
I don't refute that. I choose not to believe the universe is accelerating and will end in a rip.
2.The Big Bang theory has the support of the Cosmic Background Radiation.
Sounds like static to me.. [O8)]
3. The Steady State / Infinite Universe idea is hard to sustain.
I don't believe in a steady state. As I understand it, our galaxy is heading toward an even larger galaxy, while smaller ones orbit ours. That's not steady, nor does it infer expansion.
4. A finite Universe must either be expanding, contracting or 'just happen' to be on the cusp between the two; gravity must be at work, pulling everything inwards.
As I understand, gravity is pulling. But there is ~13 billion light years of stuff, we can see, pulling. But which way is in, conversly, which way is out? I suspect we're on the in of sides.
5. The effects of General Relativity have been measured (you can do this in the Lab, too) and the shift due to the masses would not be enough.
I wish when the General Theory was first proven, during the eclipse, the spectrum of the light was measured too. I'd like to know how much light changes when it's bent. I don't have a lab nor the tools with which I could bend light and measure the shift.
But I postulate the simple act [???] of bending light causes a shift.
6. You would have to support your argument with a lot of Quantitative evidence and calculation. Qualitative argument is not enough for such a radical idea.
I can't even count galaxies :( Nor do I know exactly how many times the Milky Way Galaxy shows up in the Hubble Deep field view?
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The other explanation of red shift which is different to the stretching thing, is that during the big bang everything was very close together so you were in a huge gravitational potential well and the light has been climbing out of it, and so redshifting, ever since
There's a lot of gravity pulling on stuff, everywhere we can see. The universe had to be pretty evenly distributed when it got started, otherwise, we would have other issues with gravity.
13 Billion light years.... How many galaxies would a strand of light be affected by en route? How close would it need to be to either of them, to be affected?
Supermassive blackholes have a pretty tight grip on the stuff around them. I guess if we could get a snapshot of a supernova going off on the other side of our galaxy, my question would be answered.
If there's something on the outside of the universe, it'd have to be pretty darn big to explain the accelerating universe.
But then, maybe each galaxy is a speck of spittal and nobody blessed god when he/she sneezed. Maybe we should be glad (s)he didn't cover their mouth.
Doh, it's late here and I ramble... I love he exchange of ideas tho.
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shemgie: You are entitled to have any beliefs you want but unless they are backed up by, either data or the ideas of someone with data and coherent theory, the beliefs are not scientific. Your beliefs are along the lines of 'green cheese' without some added substance.
You can't beat a bit of rigour when coming to Earth shattering conclusions.‾
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shemgie: You are entitled to have any beliefs you want but unless they are backed up by, either data or the ideas of someone with data and coherent theory, the beliefs are not scientific. Your beliefs are along the lines of 'green cheese' without some added substance.
You can't beat a bit of rigour when coming to Earth shattering conclusions.‾
I don't believe this idea is along the lines of green cheese.
The first proof of General Theory was during a solar eclipse. Star light was bent as it passed near the sun.
Gravity affects the shift of light.
The Question I cannot answer is how much residual shift there is when light is bent by passing (near???) a galaxy/super-massive black hole.
Unfortunately, I have no means to provide data and to support nor deny my conclusion, possessing much ignorance w/a lack of formal education in physics.
However, I believe the idea has plausibility. I brought this idea to this forum hoping to inform people with interest, whom might be better equipped explore it.
Gravitationally bent streams of light waves seem like a very plausible explanation for the shifting of light. Even if it's not the only reason, it's never been mentioned in any video magazine's I've seen. Which leaves me to wonder if it has been explored by anyone.
How often do you look up at the stars and wonder which way the light bent before it reaches us. Does it get bent at all? Are there any residual effects on light when it's direction is changed by passing a galaxy?
I apologize if my futile attempts of humor have come across as crass or anything other than humor.
Before I posted my idea, I found this link which doesn't directly support the idea, it does however lend it some merit.
http://en.wikipedia.org/wiki/Gravitational_redshift
I had hoped for a philosophical debate, not simply "it's been decided," and that be the end of the story.
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Aditionally, as far as I know for the definition of a gravity well, it would be that if the light goes in and then comes out it will have the same energy. i.e. it will be blue shifted as it enters the well and red shifted in coming out.
Even if it changes direction?
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Yes, unless as daveshorts said and the object causing the gravity well is moving. Rather than a gravity well you could think of a mirror reflecting light back to you. If the mirror is stationary the light will get reflected back without any doppler shift. If the mirror is moving towards you the light you get back will be blue shifted. From an energy perspective, the mirror is converting some of its kinetic energy into the more energetic bluer light; whatever is pushing the mirror against the light has to do work by moving the mirror against the light pressure. The fact that light is being deflected, and by whatever means, makes no difference to the principle, it is just that the maths gets harder.
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Well ofcourse, all that has been said is true. Yet it is interesting, why should the red-shift be attributed to the doppler effect and to nothing else? It is a valid question and one that needs to be addressed.
Yet certain configurations of light would admit to an explanation involving the doppler shift and nothing else. It is a fascinating subject and one which requires a lot of thought.
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We acknowledge that red shift happens. It is clearly caused, at least in part, by recession; as I said before, you can see it happen in a lab at speeds of cm/second.
There are observations (parallax) which correlate recession with distance where there is not a lot of (visible) mass between us and what we see
There is almost certainly some effect of gravity on the received wavelength but can you actually show / refer to any evidence that this is greater than the good old doppler effect? It strikes me that there is plenty of evidence available, relating distance with red shift and also plenty of data about relative density of the space in between, in different directions. That would imply that the gravity factor you want could be found.
The simplest explanation which involves the fewest factors is usually the best one to go for - Science is reductionist and with good reason.
You can choose to believe what you like but you have to CONVINCE other people with something more than that.