When we say the universe is expanding, do we just mean the stars and galaxies are becoming further apart ?

Question

Or, do we mean that all the elementary particles that make up the universe are expanding in size as well?

In other words, are all the stars and galaxies flying away from each other, while the particles that they are made from are staying the same size and distance from each other - and hence the universe is becoming more 'diluted', OR, is it just that all the stars and galaxies are staying the same relative size and its the elementary particles that are expanding - and hence the universe is not becoming 'diluted'?

Answer 1

Time, distance and cirection are relative in space. However, I think the idea of that is that the stars, planets and galaxies are moving farther apart. Some also say that when they reach a certain point, they will collapse back in on each other and the universe will start again.

I'm not too sure I agree with that, but I'm willing to keep an ear out for new ideas and understand them as best as I can.

Answer 2

It is space that is expanding. Think of a living room that you can expand, but the furniture along the walls stay at the walls in the same relative position. It is the space between them that is getting bigger. I do not remember anything about atoms or groups of atoms (up to galactic sizes) expanding, but that is an interesting question, as well: are atoms larger today than they were 13 billion years ago?? An alternative theory to the Big Bang was the Steady State theory, in which the density of the galaxies and stars was steady, so that only an atom needed to be created, on the average, every cubic kilometer or so, from energy. Steady Staters still are around, but I think most realize the "Density" of the cosmos is decreasing. So, it is most likely the universe is becoming diluted, and astronomers now think expansion will continue on forever.

Answer 3

In the beginning there was a singularity- then the Big Bang happened-the mother of all explosions, the universe flew out in every direction and it still is flying outward, like blowing up a basketball, all the dimples move farther away from one another as it expands- the ball is the Universe and the dimples are Galaxies-
It is not known yet if there is enough mass in the Universe for gravity to halt the expansion and allow for a Big Crunch...
This is the truth- many answers you have received are not accurate-

Answer 4

Good question! It means the former - the universe is expanding in the large and the stars and galaxies are becoming further apart. On the scale of planetary systems and atoms, there is no expansion. On even smaller scales - for instance the Planck scale - we don't know exactly what happens. Thus it is possible that we are living "on the edge" - for instance space is somehow contracting for small scales, expanding for large scales, and we live in between, but this is only a speculation. We know that Gravitation acts as a contracting force (opposing expansion), so on our everyday scale there might be a fine balance between expansion and contraction.

Answer 5

The universe is increasing regularly in places the position gravity is amazingly weak -- between clusters of galaxies. interior a cluster, or perhaps better interior a galaxy, the boost is way (very a lot) a lot less. as an social gathering, the orbit of the Earth is increasing because of the regularly occurring boost, through about a million.6 x 10^-32 meters in step with 3 hundred and sixty 5 days. that's *a lot* lower than the length of an atom (3 x 10^-10 m). Even for the middle of a galactic cluster with a length of 815,000 gentle years, the boost result is two.8 cm in step with 3 hundred and sixty 5 days. (a widely used galactic cluster has many one thousand's of galaxies.) the gap interior galactic clusters is a *very* small portion of the entire universe. it extremely works out to about 0.000056%, even if we comprise the skinny halos around the cores. virtually each and every of the universe is the gap between galactic clusters. that's the position virtually each and every of the boost is taking position.

Answer 6

It's not just everything moving further apart - the fabric of space itself is expanding. For instance, space is curved, so if you went in one direction for a very long time you'd end up back where you started, and that process takes longer as space expands.

But the physical constituents of the universe - subatomic particles, atoms, and the objects made fom them - are not themselves expanding. Space IS becoming more diluted (unless there's more of it vomiting out of some giant white hole or something).

Answer 7

Yes, the bodies in our universe are all moving apart into empty space, filling it with stars, planets, comets, dust, noise, gas etc. This is as a result of the Big Bang. Eventually it will cease to move apart, and bodies with the greatest gravitational pull will compete for the position of becoming the centre of the universe. As the larger bodies swallow up the smaller, so their mass and gravitational strength will increase, until eventually all matter will once again be contained in one super dense body. When this body has compacted itself into an unstable mass of energy, the big bang will repeat itself. The universe is NOT constant, it is in a cycle over such a length of time, that we will never be able to see it. To write down the number of millenia for this cycle would take longer than a lifetime, and encircle our planet countless times.

Answer 8

i thought that the galaxies were expanding into the universe but i was wrong. the correct way is the universe as whole is expanding. the way i was told to imagine it was to think of the universe as a balloon, now pencil in your galaxies all over the balloon. now start to inflate (expand) the balloon and watch the pencil marks moving away from each other. this also seems to imply that we are on/near the edge of the universe.

Answer 9

As far as i understand it, the expansion of the universe is uniform at every point which means that the distance between neighboring stars is slowly increasing while the distance between stars that are very far apart is increasing much rapidly, the edges of the universe are falling apart at a rate which is many times the speed of light. that's why the size of the universe, in light years, is much greater then it's age in years.

Answer 10

Matter remains the same size: the expansion of the universe means that the galaxies are moving away from each other. This was first detected back in the 1920's by Edwin Hubble and can be measured by observing the Doppler shift (red shift) in the light that reaches us from these galaxies.