Im confused

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Discussion

tom2019

Original Poster:

770 posts

196 months

Wednesday 23rd October 2013
quotequote all
If an object is 30 light years away, isnt that object isnt that object going to be at least 30 years old??

Looks like im a retard or someone messed up on the bbc news story about the new galaxy.

B17NNS

18,506 posts

248 months

Wednesday 23rd October 2013
quotequote all
You see the light from it 30 years after it lit up. The light took 30 years to travel to you.

If you see that light for 30 years then it is 30 years old. It might be 60 years old, but you won't know for another 30 years.

Edited by B17NNS on Wednesday 23 October 20:36

Dracoro

8,685 posts

246 months

Wednesday 23rd October 2013
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What's more, that object may have died/ceased to exist 29 years ago! The object may have only lived for a very short time.

Puggit

48,489 posts

249 months

Wednesday 23rd October 2013
quotequote all
tom2019 said:
If an object is 30 light years away, isnt that object isnt that object going to be at least 30 years old??
Almsot - we are looking at the object as it was 30 years ago... It might not still be around hehe

GTIR

24,741 posts

267 months

Wednesday 23rd October 2013
quotequote all
I wonder if those planets have grammar police?

tom2019

Original Poster:

770 posts

196 months

Wednesday 23rd October 2013
quotequote all
So unless the universe is 30 billion years old some at the bbc messed up...

sunbeam alpine

6,948 posts

189 months

Wednesday 23rd October 2013
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It's actually not so difficult - some objects are very small, some objects are far away. smile

TwigtheWonderkid

43,425 posts

151 months

Wednesday 23rd October 2013
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tom2019 said:
So unless the universe is 30 billion years old some at the bbc messed up...
What? 30 light years away. The light you see today was made 30 yrs ago. The universe is 13.7 billion years old.

But at the big bang, some objects were projected in the opposite direction from the suff that led to our formation. So, in theory, could be 27.4 billion light years away.

tom2019

Original Poster:

770 posts

196 months

Wednesday 23rd October 2013
quotequote all
TwigtheWonderkid said:
What? 30 light years away. The light you see today was made 30 yrs ago. The universe is 13.7 billion years old.

But at the big bang, some objects were projected in the opposite direction from the suff that led to our formation. So, in theory, could be 27.4 billion light years away.
The bbc article says 30billion light years away my bad..

If it was the the case that we are in the exact opposite direction and it is nearly 30 billion light years away that would mean we would be tavelling away from each other at twice the speed of light and would therefore never see this other galaxy..

Allanv

3,540 posts

187 months

Wednesday 23rd October 2013
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GTIR said:
I wonder if those planets have grammar police?
Well that was helpful frown

I read it and could understand the question so I think you may have the problem.

Mr Happy

5,698 posts

221 months

Wednesday 23rd October 2013
quotequote all
tom2019 said:
TwigtheWonderkid said:
What? 30 light years away. The light you see today was made 30 yrs ago. The universe is 13.7 billion years old.

But at the big bang, some objects were projected in the opposite direction from the suff that led to our formation. So, in theory, could be 27.4 billion light years away.
The bbc article says 30billion light years away my bad..

If it was the the case that we are in the exact opposite direction and it is nearly 30 billion light years away that would mean we would be tavelling away from each other at twice the speed of light and would therefore never see this other galaxy..
I always understood that kind of distance/time to mean that it would take 30 billion years, travelling at the speed of light to get to position x. In other words, a very, very, very, very long way away.

sunnygym

996 posts

176 months

Wednesday 23rd October 2013
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Allanv said:
Well that was helpful frown

I read it and could understand the question so I think you may have the problem.
In other words bore off you tt !

Aimed at gtir

Urban Sports

11,321 posts

204 months

Wednesday 23rd October 2013
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What is the object? If it's the millennium falcon then your guess is as good as mine.

tom2019

Original Poster:

770 posts

196 months

Wednesday 23rd October 2013
quotequote all
Looks lile im not the only one whose confused.

GTIR

24,741 posts

267 months

Wednesday 23rd October 2013
quotequote all
sunnygym said:
Allanv said:
Well that was helpful frown

I read it and could understand the question so I think you may have the problem.
In other words bore off you tt !

Aimed at gtir
I hope you two never meet. That'd be the dullest party imaginable.

Chill out you dullards. It was a joke. biggrin

DWS

657 posts

219 months

Wednesday 23rd October 2013
quotequote all
OK. I am not a scientist.
As far as I understand light travels at 1860000 miles per second (Happy to be corrected)
Hence the Sun rises and sets approx. (Again happy to be corrected) some 8 Min before you see it rise / 8 min before it sets.

Or am I talking carp?

davepoth

29,395 posts

200 months

Wednesday 23rd October 2013
quotequote all
DWS said:
OK. I am not a scientist.
As far as I understand light travels at 1860000 miles per second (Happy to be corrected)
Hence the Sun rises and sets approx. (Again happy to be corrected) some 8 Min before you see it rise / 8 min before it sets.

Or am I talking carp?
No, it doesn't. the light travels in a (very nearly) straight line. So even if the speed of light was infinite, you wouldn't be able to see the light until he moment that the earth gets out of the way of the sun, so to speak.

However, the sun might have exploded seven minutes ago and we don't know about it.


GTIR

24,741 posts

267 months

Wednesday 23rd October 2013
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Nope. Still here.


Oh, hold on what's that...

ewenm

28,506 posts

246 months

Wednesday 23rd October 2013
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tom2019 said:
The bbc article says 30billion light years away my bad..

If it was the the case that we are in the exact opposite direction and it is nearly 30 billion light years away that would mean we would be tavelling away from each other at twice the speed of light and would therefore never see this other galaxy..
You need to take into account that the Universe is also expanding (space is getting bigger). So the age of the universe and the size of the universe are not linked directly. There is also a period in the early universe of very very rapid expansion of space.

ewenm

28,506 posts

246 months

Wednesday 23rd October 2013
quotequote all
See this diagram: