× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
t
7
m
6
k
6
F
5
j
5
t
5
j
5
G
5
f
5
a
5
d
5
c
5
New Topic  
juliabreslin juliabreslin
wrote...
Posts: 96
Rep: 3 0
11 years ago
According to my reference, by the beginning of the matter era, the universe was only 300,000 years old, but had already expanded to a diameter of 100,000,000 light years. Since light speed is unobtainable in the universe, how then did the universe itself exceed that?
C'mon... nobody found this question interesting???
Read 949 times
10 Replies

Related Topics

Replies
wrote...
11 years ago
The speed of light theoretically can be exceeded when you get into some of the detailed math of quantum physics and quantum mechanics.  A fun fact, a U-235 reactor core glows blue and it's theorized that particles exceeding the speed of light is the source of the blue wave lenght as the particles interact with molecules of water. 
wrote...
11 years ago
If you want to go with the scientific viewpoint of the creation of the universe, it was created by the Big Bang about 10 billion years ago.


Also, remember, when one approaches the speed of light (not reaches it, but comes close), time slows down.

Sorry I couldn't be more help to ya.
wrote...
11 years ago
The universal expansion is NOT a speed. It is a percentage per second. This is because there is nothing really moving in the expansion at all. It is space that expands between the galaxies, and the galaxies are just along for the ride. Every second, all distances in intergalactic space expand by that percentage.  A large enough distance, and that percentage of that distance per second is greater than c. Only actual, local motion is restricted to c. The motion you are talking about is neither actual, nor local.
wrote...
11 years ago
Well, on the assumption that that theory is correct, and it is just a theory, then I'd have to say that the universe or whatever it is that our universe expanded into is bound by a different set of laws that allowed for this expansion.
wrote...
11 years ago
Inflation explains several different things: why the universe is large, why it is homogeneous, why it looks approximately the same in all directions, why it started expanding simultaneously. It also explains how galaxies have been formed out of quantum fluctuations.
Above all, we need to explain why different parts of the universe look approximately the same. Imagine that the universe just started. At the very earliest time we can consider [10-43 seconds after creation, called the Planck time], our universe was a fraction of a centimeter. In this time, light and radiation could only have traveled a tiny part of this space. So the left side of the universe could not know about the right, and the middle about neither of them: there was no time for such contact. Then all of a sudden we have a universe where everything is exactly the same. This looks like a miracle?something physicists do not expect.
This is where inflation comes to the rescue. In the simplest version of the theory, inflation starts at the Planck time. Until 10-35 seconds, space would blow up by the power of 10 to the thousand billion, rather like an elastic membrane stretching in all possible directions at a speed faster than light to a size much larger than the universe you now see. Our universe would then be a tiny spot on a huge cosmic balloon.
wrote...
11 years ago
José Frink is right even today we talk about the observable universe because there are points which we can never see because they are so far away from us they are receeding faster than light and it would appear from measurements of type 1a supernova suggests that the farther away objects are not only are they receeding faster but that the rate of recession is increasing.

As a note reactors glow blue because of partiles travelling faster than light in that medium (not a vacuum), it's called ?erenkov radiation
wrote...
11 years ago
This is Guth's inflationary theory but the principal that restricts the speed of light existed before anything ever reached the speed of light.
  This principle restricted the acceleration of the expanding universe such that  in the first 30 billionths of a second it built up tremendous density before it reached it's radial velocity of "C"
  Inflation is something that did not and could not have happened.
 
wrote...
11 years ago
Whats with all the long answers? Its very simple: space itself is expanding. The "speed of light" is really the "speed of light through space in a vacuum."
wrote...
11 years ago
In Special Relativity, one object can't have a speed greater than c, relative to another object.

In General Relativity, one object can't PASS another object at a relative speed greater than c. If one object is far ahead or behind the other, acceleration stretches or compresses the space between them in proportion to the distance. If the distance and acceleration are great enough, the distance can change a rate greater than c. Changing distance due to stretching or compressing space is not considered to be a speed in General Relativity.
wrote...
11 years ago
That is a really cool question. The speed of light is defined in reference to the universe that it travels through, when the universe was smaller, light was slower (but it wasnt to someone who would be there at the time, because they were also slower and so perceived light at the same speed we do), and all speeds and distances are relative to masses in space. Space itself is a byproduct of masses and their positions, according to modern physical theory there would be no space if there were no objects to have space betweenn them.

So my point is that, The universe expansion is not governed by the same restrictions as objects moving though space inside the universe.

Hope I am right.
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1014 People Browsing
Related Images
  
 230
  
 277
  
 571
Your Opinion
Which 'study break' activity do you find most distracting?
Votes: 820