time and space

[mullac2001]

sorry if this has been answered countless times.

according to stellarium sirius is 8.6 light years away.

when i see it NOW am i seeing it as it WAS i.e. in the past ? because the light takes so long to reach me ?

[Guest]

Yes, that is corerct. Our sun is about 8 light minutes away so you are even seeing that as it was, not as it is.

[mullac2001]

i was using sirius as an example . so when scientists say "we are going to put a telescope into spece to look into the past" this is the principle ?

[mullac2001]

thanks for replying by the way

[casemore]

Yes. Light is the universal speed limit, so essentially it is looking into the past.

[Andymac79]

Yes, that is corerct. Our sun is about 8 light minutes away so you are even seeing that as it was, not as it is.

You see everything as it was, the present is unknowable.

[mullac2001]

so still taking sirius as an example if i look at it now , how long ago would i be seeing it in its terms roughly ?

[Andymac79]

About 8.6 years ago.

[mullac2001]

You see everything as it was, the present is unknowable.

please dont confuse me even more. i think you know the gist of my post . no offence intended

[ollypenrice]

please dont confuse me even more. i think you know the gist of my post . no offence intended

But it's true and very simple. Information takes a while to reach you, even if that isn't long. Bang your finger with a hammer and there's a (regrettably short) time lapse before you feel pain. There's a slightly more favourable time lapse between a firm sending you a bill and you receiving it. But all information takes time to travel.

Or does it? Some quantum events seem to communicate instantaneously.

Anyway, the idea there there is a past, a present and a future is just a theory of time and one which is beginning to look a bit outdated...

Olly

[mullac2001]

About 8.6 years ago.

so if my youngest son who is 6 looks at sirius today , he is seeing at sirius as it was roughly 2 and a half years before he was even born ?

[tibbz2]

so if my youngest son who is 6 looks at sirius today , he is seeing at sirius as it was roughly 2 and a half years before he was even born ?

Yup!

[Andymac79]

If you look at Andromeda you see it as it was before our humans were up and running, and thats our closest galaxy. The list goes on.... And on. And on.

[mullac2001]

Yup!

man i am going to be the coollest dad ever !

[mullac2001]

If you look at Andromeda you see it as it was before our humans were up and running, and thats our closest galaxy. The list goes on.... And on. And on.

thanks everyone for clarifying what i thought was right for me. i have got sooo much to learn and now im an old git wish i had listened at school!

[mullac2001]

just to further my education ,betelguese may have supernova"d and we dont know it yet?

[mrjolly]

It's something I always think about whenever I'm looking up at something in the sky or do a bit of research after. Realising how long the light from that object has been travelling through space is pretty mind boggling!

Even something like the Orion Nebula, you're seeing as it was 1,300 years or so ago. When the light started out towards us the world was a pretty different place back then!

[mrjolly]

just to further my education ,betelguese may have supernova"d and we dont know it yet?

We'll find out about 640 years after it goes bang!

[mullac2001]

We'll find out about 640 years after it goes bang!

thankyou.

i have a lot to learn but maybe got the basics sorted in my head

thankyou for replying

[mullac2001]

But it's true and very simple. Information takes a while to reach you, even if that isn't long. Bang your finger with a hammer and there's a (regrettably short) time lapse before you feel pain. There's a slightly more favourable time lapse between a firm sending you a bill and you receiving it. But all information takes time to travel.

Or does it? Some quantum events seem to communicate instantaneously.

Anyway, the idea there there is a past, a present and a future is just a theory of time and one which is beginning to look a bit outdated...

Olly

can you elaborate for me please

[DoodleDragon]

I think I've gone crosseyed....

[Andymac79]

It has been noted buy scientists that two (entangled) particles, protons for example can be some distance apart (maybe an infinite distance) and communicate with each other with no time lag, ie what happens to one happens to the other at the exact moment with no obvious path of communication between them.

Quantum entanglement is Just one very weird aspect of quantum physics, then again the quantum maybe very normal throughout the universe and our brains and perception is just not able yet to comprehend such goings on.

[NotSoSuperNova]

Ooh, I like this thread. I might incorporate distance into my planning, for perspective. Do many people do that already?

[Jessun]

I read an article in a magazine about the signals we've been sending out in space. Were you an observer in orbit around Sirius you would know about the launch of Facebook by now.

/Jesper

[mullac2001]

so let me get this right.

the light from the sun takes 8 minutes roughly to reach us.

i"m looking at a sunset 2 minutes before its going to dip below the horizon.

actually its already gone ?