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Andrew Whalen
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Hello Everyone,
This is my first post, and I don't have any formal background in cosmology. I'm in the middle of reading a book called 'The Exploration of Outer Space' by Sir Bernard Lovell and I find myself falling in love with this topic!
I have a question that has gnawed at my head for a long time: How can we create a map of the universe when the light, radio waves, x-rays, etc. that we measure with our measuring instruments here on Earth (and in orbit) are actually measuring an extremely large spectrum of time?
When we create a map here on earth, we are able to place and associate the various parts of a map with each other because we can prove and validate that those things are actually next to each other (by visiting those places), and because of our observation that the most basic fundamentals of physics hold true for us (New York is not going to suddenly fly off into another dimension!).
However for the various electromagnetic waves that we are measuring here on earth, some represent cosmological entities that existed 14 billion years ago (the farthest reaches of the CMB), and some that existed 8 minutes ago (the sun). It doesn't seem logical to me to try to 'paste' all of these representations together in a single map because whatever the universe looked like (in a particular region) 14 billion years ago has most likely change dramatically in the intervening period. (E.g. Maybe the outer rim of the currently visible universe is starting to come back towards us - just for the sake of argument!)
It seems to me that if we try to piece together all the measurements we make here in our region of the universe in a given moment in time, that we will have a map that is warped over a period of 14 billion years.
Thank you in advance for helping an aspiring astronomer!
Andrew
This is my first post, and I don't have any formal background in cosmology. I'm in the middle of reading a book called 'The Exploration of Outer Space' by Sir Bernard Lovell and I find myself falling in love with this topic!
I have a question that has gnawed at my head for a long time: How can we create a map of the universe when the light, radio waves, x-rays, etc. that we measure with our measuring instruments here on Earth (and in orbit) are actually measuring an extremely large spectrum of time?
When we create a map here on earth, we are able to place and associate the various parts of a map with each other because we can prove and validate that those things are actually next to each other (by visiting those places), and because of our observation that the most basic fundamentals of physics hold true for us (New York is not going to suddenly fly off into another dimension!).
However for the various electromagnetic waves that we are measuring here on earth, some represent cosmological entities that existed 14 billion years ago (the farthest reaches of the CMB), and some that existed 8 minutes ago (the sun). It doesn't seem logical to me to try to 'paste' all of these representations together in a single map because whatever the universe looked like (in a particular region) 14 billion years ago has most likely change dramatically in the intervening period. (E.g. Maybe the outer rim of the currently visible universe is starting to come back towards us - just for the sake of argument!)
It seems to me that if we try to piece together all the measurements we make here in our region of the universe in a given moment in time, that we will have a map that is warped over a period of 14 billion years.
Thank you in advance for helping an aspiring astronomer!
Andrew