mapping the universe?

Question

I dont understand how we map the universe

and the concept of bubbles and voids

Answer 1

dont let bruce mislead you....although his thinking is rational, he has not thought it all the way through...think about this...i can point my telescope to any position and i will know exatcly what is there, based on "maps" even if it doesnt exist anymore because it has "died" i wont be able to know that for many years because of its great distance. so maps are ver useful for studying the origin and eventual fate of the universe. now about the "bubbles" basically they are regions of space where galaxies surround what appears to be a big "ball" of empty space. this space is expanding and making it look kind of like someone blowing up a ballon with galaxies drawn on it. i hope this helps!!!!!!

Answer 2

The old professor says: Y'know "kool!!!" The question is good, but in reality it is impossible. We can make star "maps" based on what their apparent positions and calculable distances are as seen right now from Earth. But it isn't going to be of much use except for the nearest parts of the U.

The reasons for this? If you go out and look at the stars tonight, what you are seeing is not really there! Why? Because if you look at a star that is 30,000 light years away, that means the light from that star left it that many years ago. In the meantime, that star has moved and is not now where it was 30,000 years ago. In fact, it could have gone "out of business" during those years and we still don't know it. The further away the star or galaxy is, the more it has moved. It is impossible to say where each of the billions of nearby stars are right now since they have all moved and have done so at different times. We can't even map the 100+ billion stars of our own galaxy showing where they really are right now much less the stars of the over 100+ billion galactic clusters throughout the observable U. A computer would have to calculate each star's proper motion, its number of light years away from us and its present apparent location to calculate where it is really right now. Some computer project, huh?

So, any "map" of the universe is very inaccurate and thus of little value for interstellar navigators. Thus, using the words of Star Trek's Scotty...."It kinna be done." The maps that are made are strictly conjecture and are quite abstract.

Answer 3

All you need to do is look in the night sky, and figure out how far away every object you see is. Then you plot is all on a map. Simple!

Well, the tough part is figuring out how far away everything is. In practice, what we look for when objects are "nearby" (within 100-200 million light years) is for Cepheids, which are stars of known brightness and certain kinds of supernova. We assume the laws of physics are the same far away, so we can deduce how far away other galaxies are if we find these stars.

Farther away, we depend on the Hubble effect, which assumes that the faster an object moves away from us, the farther away it is. This is mildly controversial, but probably true.

Answer 4

They use photographs to map galaxy positions, and then estimate the distances based on redshift to add the third dimension. The positions go into a computer database. The important information is not where any particular galaxy is located, but statistical analyses that show how matter is distributed in general.

Answer 5

Hi. If you look into space you see things. Stars, galaxies, galaxy clusters, super clusters, the background radiation. The distances to these things can be approximated. Bubbles are large groups of galaxies surrounding large voids where we see very little. The 'map' is a 3D plot of what we see.

Answer 6

There is a special telescope called the Sloan Digital sky survey, It uses special disks with holes . Each hole represent a galaxy. and what they do isMeasure how much the galaxies are moving away or moving close to each other.
We in the Milky way are in what scientists call the local group heading toward the Virgo supercluster. On the way there, Andromedea will collide with us with in five to ten billion years. It also measure how much dark spaces between galaxies and How gravity and dark matter bends light in a telescope, almost likea lens.