Why do scientists say that the universe is expanding?

Question

Why do scientists say that the universe is expanding? How can it be expanding? Just think of it... if the universe is expanding, that implies that it is in something? And if so, what is outside our Universe?

Therefore, why cant it be possible that the universe is infinite not moving but that the substance inside the universe is moving (Galaxies, stars etc in motion) ???

Answer 1

Your hypothesis could be right. Keep thinking that way.

Scientists work from the measurements on RED SHIFT of light waves from distant stars. It indicates what coud be expansion. But some disagree.

Relativity theory defines the Universe as being unable to exist where its fields from matter cannot be felt. Thus they say it is in "itself" and space and time lose all meaning beyond that boundary.

They think it all started with a single explosion from which all matter came. There are a few minor details that don't fit their equations. You know what that means. Keep thinking.

Answer 2

when objects are expanding (moving away from each other), it doesnt mean it is inside 'something', it simply mean THEY ARE EXPANDING!
as for what is outside our universe, that beats me... because the universe are made out of more than 4 dimensions (according to string theory), and no one as been able to probe outside the universe, so they simply assume there is nothing out there.

and the formula of bending space-time like a piece of paper is a hot debate now, perhaps one day that might put you in the spot at the farthest region of our universe, or beyond?
keep your heads up~

"Therefore, why cant it be possible that the universe is infinite not moving but that the substance inside the universe is moving (Galaxies, stars etc in motion) ???" - you are implying that everything is moving away, therefore you need to ask "what is beyond our universe?"

Answer 3

Scientists say that the universe is expanding because when they measure the distances between objects in the solar system, those distances are gradually getting bigger and bigger.

There is no implication that the universe is inside something. The universe is in empty space. There is no measurement of empty space. Who cares what is beyond the known uiniverse...The distance involved is on the order of 100 million light years, and that is such a fantastic distance that the possibilities are endless.

Who knows why the things you suggest cannot be possible? We only know what scientists, astronomers, and star gazers observe and report. What actual observations have you personally made. What equipment were you using at the time that these observations were made? Did you post your calculations in a scientific journal for others to see and work through themselves? Did you post your qualifications as a
technical researcher? And, did you post your work history in the field of astronomy or a related field with your report?

Answer 4

The Universe is believed to be expanding because of the Doppler Effect Red Shift.

Similar to the sirin of an emergency vehicle passing you at speed. As they approch you don't hear them until they are almost on top of you and as they pass and get further away, the sound of the siren becomes lower pitched. The sound waves of an object approching you crunch up and as it moves away, they stretch out.

This applys to electromagnetic waves (light) as well, and is known as spectrum shift. An light emitting object moving towards you will shift towards the blue end of the spectrum while objects moving away shirt towards the red.

We believe the universe is expanding, because they all shift red proportional to thir distance.

What is important to understand, here, is HOW the Universe is expanding. The expansion of the Universe is called 'metric' expansion. This means that, for example, if there were a star at the edge of the universe as the Universe expanded, it would remain at the edge through out the expansion. The space between everything is being stretched out and everything contained in the universe is being dragged along with the stretching.

Take a rubber sheet, draw a dot on the edge. Now stretch it. The dot is still on the edge. This is similar to the way the universe is expanding. It's not like an explosion, the way you are probably imagining it, where the edge of the universe simply continues further and further and everything near the edge is left behind.

This is all consistant with every red-shift mesurement taken.

This does not prove that the Universe is expanding, or nessicarily in the way I've described, but we haven't been able to explain it in any other way.

If substances inside the Universe were the only things moving, we would not see the uniform ratio of red-shift we see everywhere, we would see less red-shift than we do in the objects moving away from us and we would see objects with blue shift that are moving closer.

Answer 5

Based on the Big Bang Theory, everything in the universe is expanding away from where the Big Bang occurred. They keep looking to make sure it is expanding because if it ever stops expanding, that means it is collapsing in on itself. They believe that Big Bangs occur repeatedly, not just once. They do not necessarily believe that the universe is in something, but that there is an outer edge to it that keeps getting bigger as long as it keeps expanding. Outside our universe would be other universes. Everything is moving, but it is all moving away from a certain spot believed to be where the Big Bang took place.

Answer 6

The distant galaxies are moving away in all directions in a predictable pattern. THis is the Hubble Constant.
Einstein's Theory of Relativty shows 3+K Dimensional SpaceTime as an entity in own right and it is this that provides the medium by which the motion is generated as the galaxies themselves are not actually moving, rather the space between them is expanding.

Answer 7

Try this..take an uninflated baloon draw spots on it with a felt pen,evenly spaced.As you blow the baloon up the spots start to move apart.Scientists have noticed this happening to stars and galaxies(look up red-shift) and have concluded that the universe is expanding like a baloon.They may of course be completely wrong but it's as good a theory as any...we will probably never know.

Answer 8

Scientists think of that the universe is increasing as a results of huge Bang. This handed off approximately 14 Billion years in the past, scientists nevertheless do not comprehend what led to it yet they have their theories yet I wont bypass into that now. The potential from the huge bang is what created the universe, each and every thing in it or perhaps time. as a results of fact the explosion had that lots ability it continues to be going as reliable as ever now many some years later. Scientists can coach that the universe is increasing inspite of the shown fact that experiments, theories, formula and so on. So in different words the completed universe is increasing as any explosion could it basically hasn't stopped yet. The earth isn't increasing as a results of fact it somewhat is created up of rely it somewhat is the left over stuff from the explosion not the truthfully explosion so it may not enhance (ok it may as a results of fact it could have had to enhance to get to the dimensions that it somewhat is now, that's down via attracting different flying rocks in area additionally basic as asteroids, meteors and so on inflicting them to crash into it and then utilising the priority from them to strengthen even inspite of the shown fact that it somewhat is somewhat extra complicated then that). i'm hoping that solutions your question.

Answer 9

Because they measure the movements of the galaxies and they are all moving away from each other.

If you see a bunch of things moving slowly away from each other and want to figure out where those things were in the past... what do you do? Assume they were all closer? Yes.

Space-time was created in the bang. Space-time is constantly created in the "space" between galaxies and stars. Therefore there was no space-time before the bang occurred.

Answer 10

The "galaxies, stars etc." are the universe. The red shifts in galactic emission spectra are the evidence of expansion. The cause of the expansion is possibly momentum from the big bang or the effects of dark energy.