Why is the light from the "big bang" just getting here?

You, and several of the answerers here, are suffering from the common misconception that the Big Bang was an explosion that happened at a particular place in space, spewing galaxies in all directions.

The BB was not an explosion. It did not occur at a particular point in space. Galaxies are not spewing into the void. The BB is another name for the hot early universe, which was hot and dense absolutely everywhere, and galaxies are pretty much where they always have been for all time.

Imagine being a raisin in an immensely huge raisin nut bread. There is no place in the bread where there are no raisins, but they are all moving away from you as the bread rises, no matter which raisin you are on. But the raisins don't fly through the bread; they are pretty much where they always have been, as more bread is being created between them.

The universe is like that. All of space is uniformly filled with galaxies everywhere. There is no void place into which the galaxies are streaming, nor are they whizzing away from a central point. The galaxies are pretty much where they always have been; they're not flying through space; space is constantly being created between them. The only difference with the raisin bread is that the raisin bread has edges and the universe does not.

If there's more space between the galaxies today, there must have been less yesterday. 13.7 Gyr ago, there was very little space indeed and everything was very hot. There was not a hot *place* in the universe; the whole universe was very hot. We call that early universe the Big Bang.

There are some places in the universe that are so far away that it takes light 13.7 Gyr to get here from there. When we look at those places, we see them as they were 13.7 Gyr ago, as the hot dense state of the whole universe. Indeed, in every direction around us 13.7 Gly* away, we see the cosmic microwave background.

NOTE: The Cosmic Background Radiation is coming to us because everywhere in the universe, in all directions from us was hot 13.7 Gyt ago. It is NOT, as some other answerers have said, because the light has been bouncing around for 13 billion years. When you see a CMB photon, you are seeing a photon that was last scattered 13.7 billion years ago, and (unless you're looking at it through a cloud of gas or something) it has not interacted with anything else since then.

We are not "just now" seeing the light from the BB. That background is visible whenever you look. If you look when the universe is X years old, you will see the background about X light-years away*.

*There are subtleties in measuring distances that large because the universe has curvature, so this is kind of an oversimplification.

The earth and solid planets are composed of heavy elements that did not exist after the Big Bang and are the debris of super novas that fused lighter elements. Stars in the Milky Way are at great distances and other galaxies are even farther away. When we look at a galaxie we are seeing light that was emitted long ago and the farther away a galaxy the longer ago the light was released. Astronomers can now see back in cosmic history almost to the period when there was mostly energy and little matter other than hydrogen and helium. The universe is expanding like a 'rising' ball of bread dough where every point within the dough is increasing its separation (except for very local bodies that may converge and collide). Light can still reach us from the other side of the 'ball of dough' but it has traveled an exceptionally long time and is truly ancient history. The Doppler effect lowers the frequency of sound waves of a train whistle that has passes us because the waves are stretched out. Light-wave frequency from the other side of the Universe is stretched out as though it is a 'whistle' on one speeding train being heard on a train speeding in the opposite direction.

There are some misconceptions here, while it reasonable to say that the big bang did not appear at one point in space that is because there was no space. The singularity of the big bang was a pin point of pure energy and it did not explode, it expanded until the temperature cooled to a point where the first sub atomic particles appeared, that was the beginning of space, gravity and motion. These particles formed hydrogen and helium and there was an abundance of electrons, from there the universe evolved into what is today. The light from this event had long passed the point where Earth formed and it now if found in the form of micro waves at the edges of space, those waves have cooled to 3K. They are detected where ever instruments are aimed in space.

The "light" from the big bang has always been here, but the expansion of space has turned it onto microwaves because of the doppler effect. All of space was once smaller than a pinhead, and as space expanded the light of the big bang expanded along with space, since there is nowhere else for it to go. It comes from every direction and always has because it follows the expansion of space.

Wow are you confused.

Big bang happened about 13.7 billion years ago. Earth formed a bit over 4.5 billion years ago. The radiation from the events after the big bang has been bouncing about in the Universe for more than 13 billion years. It is not just getting here, it has always been here.

Ir is not like that.

It is like we were all in an explosion. We are all pieces rushing away from the center. The light and heat that we detect ARE just arriving HERE and NOW. But that light and heat comes from every direction. It has already been absorbed and re-released many times. Like the whole area after a bomb is hot, the microwave background radiation is just that kind of residual heat and is EVIDENCE of the big-bang.

Massive distances for the information in the form of light to reach us.

Image that if we could get ahead of the light that was reflected back from earth at any significant historical date, then we could see what really happened, something like a Time Machine to the past.

the light you see in the sky is still traveling from that point to this point meaning earth, and some of them are already gone from where it came from but we still getting the light coz it's still traveling from that end to our end. it's too far that's why we can still see them.

The "light" that you are referring to is backgroud radiation that is left over from the big bang. When the universe was in it's infancy, (less that 2 seconds old), chunks of matter were flying away from the center at close to the speed of light. I, for example, a particular chunk of matter, were racing away from the center of the explosion at 99.9% of the speed of light, it would take a very long time for any of that radiation to each us.