Originally posted by: RedSquirrel
Since when can they travel through time? 😱
Dude, since forever. How long have you been missing out on time travel?
😉
edit:
for an honest answer, it's not really time travel, it's simply the way we observe anything from Earth.
All light (radiation) we receive is actually "old" compared to the radiation being made at the source we are viewing.
The sun is constantly outputting light. However, from here on Earth, we are visually seeing the sun (using any instrument on or immediately near Earth, or our eyes) as it was 6 minutes ago, because it takes about 8 minutes for that light to reach Earth. So, the Sun could just go kaplooey (in reality, it can't, err... known science says that shouldn't be possible), but we wouldn't feel it, know it, or be able to identify that, until 8 minutes had passed here on Earth. Any instrument immediately next to the Sun would know it right away, but any electromagnetic waves, meaning any wireless transmission, any radiation whatsoever, would take that same amount of time to reach Earth.
In short - when we look out at the sky, using our eyes, using telescopes or even things such as the Hubble telescope, we are peering into the Universe's past, so to speak.
For all we know, a star we see in the sky that we know to be 50,000 light years away, could have went supernova 49,999 years ago. Not a single instrument would know this, until that radiation, or radiation signature, reached up. We will keep seeing that star shining ever so brightly in the night sky, until 50,000 years after it 'died'. And then we might see what actually happened at that time, such as a super bright star as we see it as a supernova.
We can visually identify things out to roughly 14 billion light years out, or at least somewhat close to that. Thus, we deduce the universe is 14 billion years old, because we cannot detect any radiation 'older' than that.
So when scientists detected that blob nearly 13 billion years old, what really happened, is they detected a blob using their instruments, but that blob was identified as being 13 billion light years away. We can basically guarantee that blob no longer exists currently, but we are currently only seeing that blob as it existed 13 billion years ago.
Does that clear that up? I hope that was clear.
