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Space Science and Astronomy thread

Osklen said:
They quote the twin study by nasa which suggested that the brother who stayed on the space station more than the other brother aged more slowly while travelling at speed around the Earth.

I’m no scientist so unable to prove if what they claim is true.
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I'm no scientist either but the fact that he ages more slowly doesn't mean there are two of him at the same time. The Law Of Identity as an equation says A + (Not A) = Everything.
 

PinzaC55 said:
I'm no scientist either but the fact that he ages more slowly doesn't mean there are two of him at the same time. The Law Of Identity as an equation says A + (Not A) = Everything.
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There isn’t two of the individual no but because the individual travelled in space, time has gone more slowly for them than relative to those people on earth, or had they not travelled in space.

I’m going to have to bow out now as too difficult for me to comprehend.

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Osklen said:
There isn’t two of the individual no but because the individual travelled in space, time has gone more slowly for them than relative to those people on earth, or had they not travelled in space.

I’m going to have to bow out now as too difficult for me to comprehend.

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Well that's my point. You cannot travel back in time because you would take atoms back to a point in time when they already existed. Time dilation is not the same as time travel in fiction where you travel either way and meet yourself. As far as I understand it, if you were 20 years old and you travelled at the speed of light to a planet 70 light years away you'd be 90 years old when you got there so it would be a pointless exercise. You could never return home and even if you could , everybody you knew would be long dead when you got there. If there are intelligent aliens on other planets the best we will probably ever able to do is talk to them by radio.
 
Reason there is a discrepancy is due to gravity aswell as the speed. time is relative. So earth time differs to space time due to gravity but to the observer in each they appear the same
 
PinzaC55 said:
Well that's my point. You cannot travel back in time because you would take atoms back to a point in time when they already existed. Time dilation is not the same as time travel in fiction where you travel either way and meet yourself. As far as I understand it, if you were 20 years old and you travelled at the speed of light to a planet 70 light years away you'd be 90 years old when you got there so it would be a pointless exercise. You could never return home and even if you could , everybody you knew would be long dead when you got there. If there are intelligent aliens on other planets the best we will probably ever able to do is talk to them by radio.
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If you travelled at the speed of light you would still be 20 when you got there. Of course such speeds are imossible if you have mass (it would require infinite energy}, but if you could approach a signicant percentage of that speed then time would indeed pass more slowly for you compared to someone, say, on Earth, so if you could return then indeed everyone you knew would be long gone.

Radio waves travel at the speed of light, so a planet 70 light years away would take 70 years to say 'hi', and our reply would take another 70 years. Not a great conversation...
 
PS said:
If you travelled at the speed of light you would still be 20 when you got there. Of course such speeds are imossible if you have mass (it would require infinite energy}, but if you could approach a signicant percentage of that speed then time would indeed pass more slowly for you compared to someone, say, on Earth, so if you could return then indeed everyone you knew would be long gone.

Radio waves travel at the speed of light, so a planet 70 light years away would take 70 years to say 'hi', and our reply would take another 70 years. Not a great conversation...
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"If you travelled at the speed of light would still be 20 when you got there"
:lol: I take it mathematics wasn't your strong subject at school.
 
PinzaC55 said:
In the examples they give are there two identical astronauts composed of the same atoms existing at the same point in time ?
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Electrons can exist in two different places at the same time.

Does that break Aristotle's laws?

Genuine question cos I haven't fully read, and certainly not fully understood them.
 
marsey said:
Electrons can exist in two different places at the same time.

Does that break Aristotle's laws?

Genuine question cos I haven't fully read, and certainly not fully understood them.
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I've heard that as well but until I hear qualified physicists say that it breaks Aristotles Laws I would discount it.
I would imagine that if an electron can "exist" in two places at the same time it is still one electron ?
 
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