General Astronomy

All this talk of looking into the past fascinates me.

So if we're looking at distance galaxies that are billions of light years away, where are we on the scale?

Is someone looking at us who are in the next Galaxy with the same perspective?
Are we past, present or future?
 
manimanc said:
All this talk of looking into the past fascinates me.

So if we're looking at distance galaxies that are billions of light years away, where are we on the scale?

Is someone looking at us who are in the next Galaxy with the same perspective?
Are we past, present or future?
Click to expand...
Great question. I've just looked it up and light never stops travelling, where does it go? Armed with a grade 3 CSE in science I can watch astronomy programmes on TV up to a point then get completely lost!
 
Sorry for the high school science question but why doesn't the light degrade, tried google but get varying degrees of answers i understand or go above my head...so explain like you are talking to a Rag or Simpleton as it is known in Manc circles
 
talkativesprout said:
Sorry for the high school science question but why doesn't the light degrade, tried google but get varying degrees of answers i understand or go above my head...so explain like you are talking to a Rag or Simpleton as it is known in Manc circles
Click to expand...
I'm no Physics expert but I would say its because there's nothing in the way to degrade light, no resistance to disrupt or distort it. You're looking at light that's travelled directly to your eye over billions of years with nothing in its way.

If there was then you simply wouldn't see it
 
markbmcfc said:
I'm no Physics expert but I would say its because there's nothing in the way to degrade light, no resistance to disrupt or distort it. You're looking at light that's travelled directly to your eye over billions of years with nothing in its way.

If there was then you simply wouldn't see it
Click to expand...

The image released yesterday does show that light can be distorted.

There is a galaxy group in the middle of the picture which is about 4 billion light years away. It is a huge mass and warps spacetime (the fabric of space).

As such the light travelling behind it is warped and bent around it, these are the arcs/smudges in the picture. That light has been travelling for 13 billion years.
 
This is the way NASA should have presented the the picture yesterday. It's incredible.

 
manimanc said:
All this talk of looking into the past fascinates me.

So if we're looking at distance galaxies that are billions of light years away, where are we on the scale?

Is someone looking at us who are in the next Galaxy with the same perspective?
Are we past, present or future?
Click to expand...

Time is relative so we're present. But we're the past for others.

(Don't have a clue).
 
talkativesprout said:
Sorry for the high school science question but why doesn't the light degrade, tried google but get varying degrees of answers i understand or go above my head...so explain like you are talking to a Rag or Simpleton as it is known in Manc circles
Click to expand...

Photons need to impact with other particles to stop or have them degrade don't they?

Edit: quick google shows that they can't degrade.
 
Kirkstall Blue said:
Fantastic beautiful life on other planets fascinates me the stars are billions of light years away so we’ll never know if we are alone
Click to expand...

Nearest star is only 4.2 light years away mate, but your statement still stands IMO because I doubt very much we will ever be able to get there.
 
Even 4.2 light years is impossible with our present technology unless Einstein had it all wrong and we can go faster than the speed of light.
It makes you realise all the UFO films of Aliens visiting us is interesting but ridiculous.
I listen to Shaun Carroll and Brian Cox purely to understand physic’s but the mind boggles at how complicated it all is.
We are looking back in time to after the Big Bang so now we’re moving further apart they just had someone on Sky to talk about the pic but cut her off to see the Tory leader election
 
Kirkstall Blue said:
Fantastic beautiful life on other planets fascinates me the stars are billions of light years away so we’ll never know if we are alone

Is this a pic taken from the new Chinese telescope ?
Click to expand...

No it's NASA made/owned but also contributions from other space agencies including the european one, ESA.

Current thinking of various astrophysicists is that life, as in Civilisations, will be extremely rare. Less than one per galaxy per many millions/billions of years. There probably hasn't been as advanced civilisation as us within the last billion years in our local galaxy group.

They think this as we detect no radiowave signals.
 
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