Expanding or shrinking?

Question

Observation shows that the universe is expanding, or that space is expanding. The Big Bang theory has been confirmed.

What I want to know is couldn't the same observational results be gotten if space wasn't expanding, but rather objects within space like galaxies, were shrinking?

They would appear to ba oving away, and there would also be red shift, right?

I guess that astrophysicits know why my contention is wrong, but I don't. Any help therefore appreciated, and I don't mind *a few* long words.

Answer 1

If galaxies were shrinking, then they would all appear to be moving away from us at the same rate. But we observe that farther objects are moving away from us faster than near objects (some of which are actually getting closer to us) which is consistent with the Big Bang.

If galaxies were shrinking then stars in our own galaxy would be red shifted toward us, which we don't observe

Answer 2

Personally, I like tho think that the apparent red-shift of distant galaxies has more to do with the properties of light over billions of years of travel than with expansion. To me, this explains the greater shift towards red the farther the object than the Big Bang does. It also seems to accommodate the background radiation as the light that is reaching us from even more distant galaxies no longer observable because of the degradation of the light.
The observed red shift also only seems to apply to galactic superclusters, not galaxies or the stars themselves. Not only do we observe constant galactic mergers, we know that Andromeda is on a collision course with us right now.
Does it not seem odd that such an expanding universe would allow for such cohesion of intergalactic/interstellar structures, since billions of years ago all the matter in the universe was supposedly radiating away from a common center?

Answer 3

Red shift would not be observed in a shrinking universe.
Think of how the Doppler effect works - in the example of a car going past you at a racetrack, the car sounds like it's making a high-frequency sound while it's approaching you and a lower frequency sound when it's gone past you and is getting further away. Light waves behave this way too.

In a shrinking universe, all galaxies on average would be approaching one another, and as they shone light toward the galaxies they approached (like ours), they would catch up a little bit to their own light waves, effectively shortening the wavelength of that light - shifting it into the blue end of the spectrum, not the red.
Blue-shifted light has been used for some time as an indicator of objects that are approaching us, just as red-shifted light has been used as an indicator of the opposite.

Answer 4

With the big question hovering over our heads, "What is dark matter?" It seems that the universe as a whole may lack sufficent mass to halt the perceived expansion. Can dark matter account for the missing mass? That will play a big role in determining if the expansion will ever cease. We may end with a dark universe with no ability to produce stars because even atoms have moved so far apart. Or, expansion could slow to a halt and contraction begin with matter getting closer and closer until finally remaking that primordial atom that the big bang was made by.

Ever think "Let there be light" sounds a lot like a big bang?

Answer 5

Recent observation have indicated other wise. The Astronomers have recently just observed four Galaxies not moving away(expanding into the Universe at a recession velocity) but moving towards each other and forming one big Unit of massive stars. So on that basis due to this recent phenomena, it can be concluded that galaxies are not all expanding away from the centerof the Universe , but also schinking(moving into each other).New theory seems to be born ,meaning that not all galaxies are moving away at a recession velocity but at an approching velocity.

Answer 6

Any time you have and explosion every thing go out from one central point, and will keep on going unless acted upon by a stronger force.
You ask if space could be expanding, well this is a really big problem, because where does space start, and where does it end?

Answer 7

Do you mean that space is stationary but only the galaxies and stars are getting smaller?

That would not account for the size of the redshift we observe. It would also be odd that while every other star is getting smaller, our star does not.