Nobody knows where the middle is, so knbody knows where the edge is, and nobody knows what is outside it. If we're expanding, we're expanding into what?
2006-12-05 00:25:33 · 19 answers · asked by Neil E 1 in Science & Mathematics ➔ Astronomy & Space
Ermmmmmm.... how do we know it is not?
2006-12-05 00:27:39 · answer #1 · answered by jonti 5 · 1⤊ 2⤋
There is a scientific method that is used to theoretically prove that a distant object is moving closer or further away...This is known as red shift. As an object moves away, the frequency of the light that is reflected back from it is reduced slightly. As an object moves closer toward us, the frequency of light is increased. So the direction that the object travels in has an overall effect on the light that is reflected.
However, if we were on the edge of a universe and could see the entire universe, then we woul dgenerally see more objects as we looked toward the centre than if we looked away from the centre. Imagine standing in a room at the edge of a crowd and looking into the centre of the room or out away from the room. you would see more people if you looked toward the centre.
So the impression that we get by combining these factors is that the universe is expanding at the same rate in every direction around us...as if we were at the centre.
If we were able to see one view of the universe that apparently had a greater density of objects than another, then we may believe that we were looking to ward the centre of the universe and that we were expanding away from that point.
what appears to be happening is that the universe does not have a centre, but that all objects are apparently moving away from eachother in every direction.
Expanding into what? is a question that you would ask if there were a single starting point, a big bang. But that is just a concept that our brains like to entertain. We have to have a starting point for everything and it generally starts in perfectiong and grows into chaos.
But frequencies of light and distances and everything else that we base our science on is calculated based on time. If we have got time wrong then we might be wrong about distances, red shift and expansion of the universe.
It could just be that everything existed when time started and fluctuations in time give us the evidence we appear to see.
2006-12-05 09:14:08 · answer #2 · answered by Sonic 2 · 0⤊ 1⤋
Think of it more as stretching. It's a bit like the surface of a balloon growing. Everything is still next to the same neighbours but the whole surface expands. The surface has no single point about which everything stretches and it has no edge. Space - time works the same way. It stretches in 3D, not expanding from a single point and with no edge.
2006-12-08 08:16:22 · answer #3 · answered by Rich 2 · 0⤊ 0⤋
If you examine sunlight with a spectroscope you'll find that it has lines in it, corresponding to the different elements in the sun. When the light from galaxies is examined it's found that these same lines are there, but they've moved towards the red end of the spectrum. This is a Doppler shift and it's explained by the galaxies moving away from us at high speed. The further away they are, the faster they're moving away and the best explanation is that the universe is expanding.
2006-12-05 08:39:56 · answer #4 · answered by Iridflare 7 · 1⤊ 0⤋
We know that universes we can see are moving away from each other by the Doppler effect however nobody knows what they are moving into or where the edge actually is if there is one but when scientists are studying these things they do come up with theory's based on the known facts as the laws of physics which will of course change or be confirmed as new discoveries are made.
2006-12-05 08:33:22 · answer #5 · answered by Maid Angela 7 · 0⤊ 0⤋
Wow interesting answers. Firstly, the universe is NOT infinite as previously suggested. The simplest answer is the doppler effect. Much like an ambulance siren sounds lowerpitched when moving away from you, so does light seem "coolerpitched", which is actually more reddish. We know from examining galaxies and stars what they are made of, and can predict what kind of light they are SUPPOSED to give off. However, they give off a more reddish light and we know they are moving away from us.
Lastly, do not think of it as dots on paper moving away from each other, rather think of the paper expanding. The distance between the dots increase, but are relatively still similar. This varying thought of universe expansion seems to ring clearer with alot of people.
2006-12-05 08:41:02 · answer #6 · answered by Joecuki 2 · 1⤊ 0⤋
Technically, the metric expansion of space is a feature of many solutions to the Einstein field equations of general relativity. In particular, if the cosmological principle is assumed with a time-varying universe the simplest solution allows for the distances in space to change with an evolving scale factor. This theoretical explanation provides a clean explanation of the observed Hubble's law which indicates that galaxies that are more distant from us appear to be receding faster than galaxies that are closer to us. In spaces that expand, the metric changes with time in a way that causes distances to appear larger at later times, so in our Big Bang universe, we observe phenomena associated with metric expansion of space. If we lived in a space that contracted (a Big Crunch universe) we would observe phenomena associated with a metric contraction of space instead.
2006-12-05 08:34:48 · answer #7 · answered by johninmelb 4 · 0⤊ 0⤋
Because of redshift. The farther away the galaxies are, the faster they are moving apart. It's not expanding into empty space, because space it's self is expanding. It could only be complete non existence. A nothing deeper than death.
2006-12-05 08:37:56 · answer #8 · answered by Anonymous · 0⤊ 0⤋
If you look into the theories of measuring the universe, you may get a better picture i.e. if you understand them firstly. Get yourself: Measuring the Universe by Kitty Ferguson....she explains it laymans terms. There is no middle and no edge, just a 'warped sphere', for lack of a better analogy, that is constantly changing shape and so has to be measured in that way.
2006-12-05 09:01:31 · answer #9 · answered by the critical umbilical 2 · 0⤊ 0⤋
we know we are expanding because we are getting further and further away from the central core of peace, justice and harmony everyday. It's a difficult topic to grasp, as it depends on what you believe, but I feel the universe is expanding into God's Eternal Kingdom of Heaven.
2006-12-05 09:01:02 · answer #10 · answered by sb85 2 · 0⤊ 1⤋
Unless someone were to study astronomy and physics a good deal, this question tends to be over everyone's head. Not being mean or anything but I read Stephen Hawking's books all the time and I have no idea what he's talking about half the time, it blows my mind.
2006-12-05 08:30:24 · answer #11 · answered by Sexy_Bunny 4 · 0⤊ 0⤋