Space and stuff

[McBain]

No as others said it is irrespective of whether its by an eye or a telescope. Just a matter of how long the light takes to reach us, so if the sun completely vanished we would still see its light for 8 minutes.

Ok say using our Sun (or even voyager as its 3 times farther away) if we look at it with a telescope powerful enough to see a person, it could, for all intents and purposes, never ever see that person in real time?

Is there a certain distance that light begins to fall behind in time?

 

[maccavennie]

Ok say using our Sun (or even voyager as its 3 times farther away) if we look at it with a telescope powerful enough to see a person, it could, for all intents and purposes, never ever see that person in real time?

Is there a certain distance that light begins to fall behind in time?

My mind has completely bent out of shape due to the last two pages lol

 

[Abertonian]

Ok say using our Sun (or even voyager as its 3 times farther away) if we look at it with a telescope powerful enough to see a person, it could, for all intents and purposes, never ever see that person in real time?

Is there a certain distance that light begins to fall behind in time?

Yes. All related to the speed of light and the distance.

The speed of light is 299 792 458 meters per second. The moon is 384400km from Earth so if someone was on the moon and we looked at them through a telescope we'd be looking at them 1.28 seconds in the past.

Voyager 2 is about 11 billion miles away so if we looked at it through a telescope we'd be looking close to 16 and half hours in the past.

 

[Bluesaint]

Ok say using our Sun (or even voyager as its 3 times farther away) if we look at it with a telescope powerful enough to see a person, it could, for all intents and purposes, never ever see that person in real time?

Is there a certain distance that light begins to fall behind in time?

That person you'd be seeing would be back in time. If you saw them waving (if such details were possible) they could have waved, walked away, raised a family and ultimately died by the time you saw them waving. Stephen Fry mentioned this on QI that if someone from, I think, alpha centuri could use a telescope to look at the earth in detail it would be seeing a snapshot of life in the 1950's. Utterly crazy.

 

[McBain]

@Abertonian
@originalgreaserbob
@Bluesaint
@maccavennie

Thanks for the answers! Amazing to think that even the Planets that we can look directly at aren’t even in the positions that we think they are, and the night sky would look very different if we could see what it really looks like! Fingers crossed our Universe actually still exists!

 

[Nymzee]

It's why I grew up to call stars memories.

 

[Taifi gorm]

That person you'd be seeing would be back in time. If you saw them waving (if such details were possible) they could have waved, walked away, raised a family and ultimately died by the time you saw them waving. Stephen Fry mentioned this on QI that if someone from, I think, alpha centuri could use a telescope to look at the earth in detail it would be seeing a snapshot of life in the 1950's. Utterly crazy.

There is also the possibility that Hitler maybe the first signal they pick up...

 

[originalgreaserbob]

Yes. All related to the speed of light and the distance.

The speed of light is 299 792 458 meters per second. The moon is 384400km from Earth so if someone was on the moon and we looked at them through a telescope we'd be looking at them 1.28 seconds in the past.

Voyager 2 is about 11 billion miles away so if we looked at it through a telescope we'd be looking close to 16 and half hours in the past.

I know it’s less accurate, but I still think of the speed of light as 12 million miles/minute. It’s the fastest speed there is!

 

[ste d' indica]

Interesting doc unfolding on BBC 2, concerning what might occur in the event of us picking up an extraterrestrial signal, combination of docudrama and scientific talking heads giving fascinating insight on everything from radio astronomy protocols to potential social impacts.

BBC Two - First Contact: An Alien Encounter

Drama-documentary exploring the discovery of a mysterious alien object.

www.bbc.co.uk

 

[Spadge Vernacular]

Spanish airspace partially closed as Chinese rocket debris falls to Earth

Huge chunk of Long March 5B rocket launched four days previously re-enters atmosphere

www.theguardian.com

 

[Goodison87]

My mind has completely bent out of shape due to the last two pages lol

Nothing compared to both the covid and brexit threads in their pomp, half page genuinely guaranteed to blow your head of for hours! Reasonable explanations galore in this one!

 

[degsy]

That person you'd be seeing would be back in time. If you saw them waving (if such details were possible) they could have waved, walked away, raised a family and ultimately died by the time you saw them waving. Stephen Fry mentioned this on QI that if someone from, I think, alpha centuri could use a telescope to look at the earth in detail it would be seeing a snapshot of life in the 1950's. Utterly crazy.

Einsteinian Physics says the speed of light is a Constant.
Alpha C. is 4.367 light years away, so any 'snapshot' can only be 4.367 years old...and the radio programs for that matter.
As far as I know anyway

 

[Bluesaint]

Einsteinian Physics says the speed of light is a Constant.
Alpha C. is 4.367 light years away, so any 'snapshot' can only be 4.367 years old...and the radio programs for that matter.
As far as I know anyway

Wasn't sure of the exact reference point in space. Obviously not alpha centuri in hindsight, but somewhere that's 60 plus light years distant. Can't remember the name.

 

[Gwladys St. Glory]

 

[chrismpw]

Einsteinian Physics says the speed of light is a Constant.
Alpha C. is 4.367 light years away, so any 'snapshot' can only be 4.367 years old...and the radio programs for that matter.
As far as I know anyway

Years back I used to teach a class that there must be no intelligent life on alpha centuri and I could prove it. The proof wentcaling the lines that Big Brother had first been broadcast around 9 years ago. Give it 4.5 years for the TV signal to reach them and around 4.5 years for their Death Ray to return to shut us up ... the fact we're still here means there cant be anyone intelligent listening on alpha c.