No one knows for sure. By 1784 science recognized the universe as being the Milky Way of 8,000 x 1,500 Light Years (LY) By 1906 they decided that it was actually 23,000 x 6,000 LY 1912 the universe size was expanded by scientists to 170,000 LY. By 1920 the dimensions of the galaxy were revised to 55,000 x 11,000 LY. (Now it is assumed to be about 100,000 x 20,000) In the 1950s the furthest galaxies said to be about 1 - 2 billion LY away. Within the next few years ( by mid 1960s) they were said to be 9 billion LY The universe is now thought to be 156 Billion LY Wide.
I have an M.S. in physics and have been teaching it for almost 20 years; astrophysics happens to be one of my interests. The universe is, as far as we can tell, expanding, so there really isn't a set "size"; this would be like asking how large an inflating balloon is. The universe is not an object like a balloon or a ball or anything else because there is simply no analogy that fits "the universe", but an inflating balloon is a good start. The current acceptable age of the universe is somewhere around 14 billion years; if the universe were a sphere, that would make it 28 billion light-years across. This is a question cosmologists have been trying to answer for hundreds of years (beginning with astronomy) and it really doesn't have a good, solid answer. The universe is the sum of all that exists, therefore it's size is irrelevant.
According to scientists, the universe is continuously expanding at this moment, so as far as we're concerned; indefinite. Also, fun fact, it takes stars many years to expand and explode, eventually, all stars will explode and possibly become black holes and many many many trillion years from now, the universe will continue to expand as a cold and completely dark place without stars.
Most of the responses here are saying the size is infinite. Lately, that theory has started to shift into - the size is finite and does NOT go on forever. However, our current technology can only measure vast distances by visible light. Unfortunately, visible light needs time to be able to reach the point of visibility, and the "edge of the universe" is further away than ALL observable light (moving at approx. 186,000mps). However, new technology making it possible to measure the sound waves created from the big bang (big bang theory). Just as ripples in a pond bounce off a shoreline, the sound waves bounce back off the "edge" of space showing a finite size, and shape. And it is now believed it is possibly shaped like a soccer ball (truncated icosahedron). A new theory has also stated that the universe is possibly not alone and a multiverse is a likely scenario, due to a new discovery of a point of space in the universe where a group of galaxies are moving together against the grain defying natural physics. The only current reasonable explanation scientists have agreed upon is another universe's mass is creating a gravitational pull at the edge of our universe.
It is the most fascinating subject I've ever tried to find out. To me it is infinite and unending space which nobody will ever be able to find.How can the Scientist say that it is expanding?If it is expanding what is the space outside it which lets it expanding?So, it is like we even can't ever imagine of. Yudhir
Have you ever surrounds its, well if it is none, it means that the universe just covering your trip and if not, it means that the universe looks large and spacious, for your curiosity about the magnitude of this universe.
It is thought that the universe is always expanding and indefinite. There are an estimated amount of 250 billion galaxies, and just as many stars, so the size of the universe isn't know to anyone, but it is very big.
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according to euclid any straight line how long it may be forms a closed circle. hence i can say if you extend both ends of the line in space somewhere they will coincide. it may take length of trillians of light years.
8 months ago
Last edited at 3:08AM on 4/30/2013
although universe is big and scientist keep researching how big it is.till know you can only give ans in philosophical way like if we consider earth as a single drop of water then universe is as big as ocean. http://www.educationkranti.com/
In the 1920s, Edwin Hubble used the 100" telescope (2.5 meters) at the Mount Wilson Observatory in California to detect variable stars in nebulae. He discovered that the stars he observed had the same characteristic variations in their brightness as a class of stars called Cepheid Variables. Earlier, astronomer Henrietta Levitt had shown there was a precise correlation between the periodic change in brightness of a Cepheid Variable and its luminosity. Hubble was able use this correlation to show that the nebulae containing the variable stars he observed were not within our own Galaxy; they were in external galaxies far beyond the edge of our Milky Way.
Hubble determined the distances to the galaxies and the velocities that they were moving at, relative to Earth. From this, he discovered an amazing thing: the farther galaxies were away from us, the faster they were moving away from us. In other words, the Universe was expanding!