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/sci/ - Science & Math

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5657324 No.5657324 [Reply] [Original]

If someone on Earth pointed a telescope at a flat mirror which always faces Earth one-half light years away, would the observer be able to see Earth from one year before?

>> No.5657328

>>5657324
no. it would take a half a year for him to gain sight of the mirror, then another half a year for him to gain sight of the earth, at which point he would see himself first looking into the telescope

>> No.5657334

>>5657328
are you retarded

>> No.5657335

No. No telescope has that small an angular resolution, nor could it.

>> No.5657347

>>5657334
Not him but are you? That's exactly what would happen dipshit

>> No.5657349

>>5657328

The mirror has been there for years doofus.

And yes OP, he would. The image of Earth in the mirror would be one light year away, so we would inevitably see things that took place one year ago.

>> No.5657354

>>5657349
>if by things you mean a faint dot of light most likely overpowered by the sun, then yes.

>> No.5657356

>>5657349
I don't know where, but if someone observe us, probably from outside the solar system, they would see the dinosaurs here.
Yes, shit is crazy.

>> No.5657357

>>5657356
what do you mean you don't know where? Its 70 million light years away. Where else could it be?

>> No.5657358 [DELETED] 

>>5657347
assuming that the mirrors has been there for longer than a half year already, it will take a half year for the mirror to reflect the arrangement electromagnetic frequencies representing the man in gazing with the telescope and another half year for that light to return to him. for him to see

>> No.5657361

>>5657357
Yes, of course. What I was thinking?

>> No.5657363

>>5657347
assuming that the mirrors have been there longer than a half year already, it will take a half year for the mirror to reflect the arrangement electromagnetic frequencies representing the man gazing afar and another half year for that light to return to him and for him to see

>> No.5657380

The light spectrum is limited in detail. You would not be able to make out very much at a light year away+reflection.

That is you might not even be able to make out the earth.

>> No.5657397
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5657397

>>5657380
u just went full retard. all u need is big enough telescope. the diameter of the telescope determines the angular resolution. have some planets 129 light years away.

>> No.5657669

>>5657363
The light from earth from half a year ago would already be there, so we would only have to wait for the light reflected after the mirror is put in place. (assuming that its possible to observe the reflected light, for those of you complaining about that)

>> No.5657692
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5657692

gravity bends light, so with enough gravity would this work?

>> No.5657713

>>5657692
No, you cannot bend it back on itself.

>> No.5657715

>>5657713

are you stupid

>> No.5657716

Yes but in order to have 1m resolution on the earth you would need a telescope ~6 billion meters across and a mirror 3 billion meters across.

>> No.5657770

>>5657328

Lol you fucking idiot (yes ^ this guy is retarded).

The light emitted from Earth/reflected from the mirror is continuous. So after a year has elapsed the Earth "1 year in the past" would be visible.

>> No.5657775

>>5657397

Thank you, exactly, you just need a large telescope. What OP described is perfectly possible.

ITT: people who hae no clue about phsyics (I swear /sci/ is dumber tonight...)

>> No.5657809

>>5657775
sure you could do it with a really large telescope. of course that telescope is not possible to build but hey go for it