Yes, I have heard the theory – judging by the distance we know how old the coming picture is. However I don’t understand why if we are looking at an object that is 17 bln light years away we assume that we see it as it was 17bln years in the past, since the speed of the expansion of the universe is higher than the speed of light and it depends on how close the object is to the center. Second – I don’t understand why we assume that the objects furthest from us are the ones that are most distant in time as the origin (big bang) must be somewhere in the center. And last - why do we think that we can almost see the big bang when it seems to me that we need to be very fortunate to live in just the right time frame that would allow us to do so, as there will need to be some great alignment between the speed of light and the speed of the expansion of the universe and the time frame that we live in. Thank you!