Hi! This may take a while, so bare with me...
Quote:
|
Originally Posted by Richard J. Hanak
I seriously doubt the idea that space is expanding and I'll tell you why. I've lived in this house for a long time and the space in the pantry closet, clothes-closets, linen-closet, storage cabinets, medicine chests and even the rooms themselves hasn't increased an iota. Worse than that, the space has definitely decreased. My garden shed is a good example. Over the course of time I have had to build two extensions to it in order counteract the so obvious contraction of space to which we are all subject. It's now triple its original size and almost out of space again!
|
The space in between galaxies is expanding. It's not that our sun and Earth, solar system, and galaxy are growing in size.
Quote:
|
Now I'm not asking any of you to risk your Ph.D. thesis on my idea of the contraction of space. I hope you will believe me when I say that my attachment to the contracting space idea has not biased me against the expanding space idea. However, I must confess that I do have problems accepting the expansion of space idea. It seems to raise many more questions than it answers.
|
I'll try to answer a few...
Quote:
|
Long ago I learned that the red shift of light from galaxies was a Doppler effect caused by the galaxies moving away from each other. Now everyone says, "No, the red shift of light from galaxies is caused by the expansion of space." Does that mean that the galaxies are not moving away from each other after all? Or does it mean that the galaxies are moving away from each other without causing a Doppler effect for their light?
|
This is a fairly common misunderstanding. The galaxies are flying apart, causing the redshift. An alternative way of viewing this situation is to say that the space in between us and a distant galaxy is stretching, causing the light to stretch and lengthening its wavelength. The two are alternative ways of viewing the same situation.
Quote:
|
If the galaxies are not receding from each other, what does that say about the evidence for Hubble's law that the recession velocity of a galaxy is proportional to its distance from us? Is Hubble's law a meaningless coincidence? Doesn't the idea that expanding space stretches wavelengths make the expanding space theory smell a little like the abandoned ether theory?
|
Nope... its two ways of viewing the same phenomenon. (Spelling???)
Quote:
|
It's all so puzzling. Why should the wavelength of light be the only thing affected by the expansion of space? Beats me.
|
What else should it affect? Gravity holds large bodies together, and electro-magnetic forces hold together smaller physical objects. These forces keep them from expanding with the expanding space-time.
Quote:
|
If the expansion of space causes light to lose energy, where does that energy go or what is it changed into as it is being lost? Is light exempted from the conservation laws so that it can just pass out of existence?
|
No. The redshifting light is not loosing energy, it's just spreading it out over more time. Think of this. If you put gasoline in a bucket and drop a lit match into it, it explodes, releasing a large amount of energy very quickly. If you put it in your car, it becomes a controled reaction, releasing the same amount of energy, over a greate amount of time. This makes it less energy per second, but the same overall amount of energy.
Quote:
|
Does the expansion of space idea imply that light continually loses energy as it travels through space? If light energy is created as quanta, shouldn't it lose energy as quanta? Does one quantum of light magically (and not continually) split off a femto-quantum from time to time as it travels through expanding space? How would a quantum of light know when to do a femto-shift? Do those femto-quanta somehow get together to recombine so we can detect them? Or do you think we should chuck quantum theory?
|
First off, when you recieve several quanta (photons) of light, and measure their properties, such as wavelength, and direction headed, according to quantum mechanics, there is no way you can say that that's how they left. You can't even say that as many photons left the source as you collected. You also can't really say that they merged on the way or anything like that, because that would mean you knew the energy of each photon when they left the source and when they arrived at your detector.
Quote:
|
Doesn't the equivalence of energy and mass mean that if the expansion of space causes light to lose energy, it should cause material objects to lose mass? Isn't it true that what's sauce for the goose is sauce for the gander? Who would deny E equals m c squared? If light travelling 99 percent of 15 billion years has lost say 90 percent of its energy, wouldn't the expansion of space have caused the galaxy that emitted that light to have lost say 90 percent of its mass? And where would all that mass have gone? (Now that' s what I would call a real weight loss program!) Would you propose a reverse of the old Bondi/ Gold hypothesis, where instead one hydrogen atom would pop out of existence every so often in order to accommodate the expansion of space?
|
Since light doesn't loose energy, matter doesn't loose mass.
Quote:
|
Don't counter that light loses energy because it moves through space but galaxies don't. Are you crazy enough to think that there is any mass object that doesn't move through space?
|
Ummm.... relative to what?
Quote:
|
Wouldn't just one thing that doesn't move take us straight back to absolute motion? Do you want to waste the last hundred odd years since the Michelson-Morley experiment and subsequent developments of SR and GR?
|
Ummm... no... I make no claim that anything is inheritently "stationary."
Quote:
|
If the height of a hill increases as you climb it, you may be dreaming or in an imaginary world. Something like that doesn't happen in the real world.
|
I'm afraid I don't follow...
Quote:
|
Can't you see that two attempts to explain the red shift raise so many new things to explain that both the previous explanations are probably unrealistic?
|
The "two attempts" are one and the same attempt viewed in two different ways. It's like saying "light is a wave" and "light is a particle." It's two different ways of looking at one specific thing, called particle/wave duality.