Linked Questions

5 votes
1 answer
923 views

Gravitationally bound systems and cosmological expansion? [duplicate]

Why are gravitationally bound systems unaffected by cosmological expansion? Is it because on local scales gravity has overcome the effects of the expansion of space and thus enabled localised ...
user35305's user avatar
  • 3,207
5 votes
0 answers
141 views

Evidence that the Solar System is expanding like the Universe? [duplicate]

I've just come across Krasinsky and Brumberg's paper that claims, from an analysis of radiometric measurements, that the astronomical unit (earth-sun distance) is increasing at the rate: $$\frac{d}{...
John Eastmond's user avatar
0 votes
2 answers
129 views

Expansion of the Universe [duplicate]

At what speed is our solar system expanding, and if it is, why don't the positions of the sun and planets change, or grow farther apart? Why is the Big Dipper still where it is?
Mark Sottile's user avatar
1 vote
0 answers
52 views

Expansion of the Universe inside mattar [duplicate]

When talking about the expansion of the universe we usually refer to the Friedman equations so we assume homogeneous and isotropic solution to Einstein field equation which is true on cosmological ...
ziv's user avatar
  • 1,734
2 votes
0 answers
37 views

is the expansion of the universe observable at a smaller scale? [duplicate]

I have searched the network for a possible duplicate to this question but I have not found one particulary answering my question so recommendations are welcome. I understand that distances of ...
Chimango Chisuwo's user avatar
194 votes
15 answers
31k views

Why does space expansion not expand matter?

I have looked at other questions on this site (e.g. "why does space expansion affect matter") but can't find the answer I am looking for. So here is my question: One often hears talk of space ...
SoulmanZ's user avatar
  • 2,055
33 votes
9 answers
9k views

Is space really expanding?

In a book called "Einstein, Relativity and Absolute Simultaneity" there was this sentence by Smith: There is no observational evidence for a space expansion hypothesis. What is observed are ...
user avatar
42 votes
6 answers
10k views

Why does a flat universe imply an infinite universe?

This article claims that because the universe appears to be flat, it must be infinite. I've heard this idea mentioned in a few other places, but they never explain the reasoning at all.
Nathan BeDell's user avatar
36 votes
4 answers
4k views

Swimming in Spacetime - apparent conserved quantity violation

My question is about the article Swimming in Spacetime. My gut reaction on first reading it was "this violates conservation of momentum, doesn't it?". I now realize, however, that this doesn'...
Keenan Pepper's user avatar
16 votes
3 answers
3k views

Is the Cosmological Constant locally zero?

On earth and in our solar system we do not notice any effects of a non-zero cosmological constant. The accelerating expansion of the universe was only detected by observing the most distant supernovae....
jak's user avatar
  • 10.1k
12 votes
3 answers
2k views

Height Issues of the Time Traveler [duplicate]

A person from the year 2250 goes back in time. They go back 60 Million years, because they want to observe dinosaurs. Imagine their surprise when they see T-Rex's running around like little chickens!...
Jiminion's user avatar
  • 2,637
12 votes
5 answers
3k views

What experimental evidence shows that the "explosion" model of the Big Bang with an explosion at a single point of space is wrong?

A popular misconception in the layman public is that the Big Bang was some sort "explosion" at a single point of space, where originally all matter was concentrated and then it "...
Nadav Har'El's user avatar
  • 2,837
25 votes
2 answers
4k views

How fast is the Earth-Sun distance changing

This is inspired by Evidence that the Solar System is expanding like the Universe?, which referenced an article by G. A. Krasinsky and V. A. Brumberg, "Secular Increase of Astronomical Unit from ...
user avatar
8 votes
6 answers
2k views

Is there cosmological redshift within the Milky Way?

Cosmological redshift is based on the idea that the universe is expanding. When the universe doubles in size, or scale factor, the wavelength of light doubles. But the Milky Way is not expanding so my ...
John Hobson's user avatar
10 votes
4 answers
4k views

As the universe expands, why do some things stretch but not others?

I got into watching a video on Olbers' Paradox a few days ago, and from there read about the origins of the universe, its expansion, and so on... it's always fascinated me, but now something about it ...
Cat's user avatar
  • 203

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