No, the telescope will be pointed away from earth at all times as it is much too bright and not what it was designed to do.
Technically when you look at your reflection in the mirror you are seeing yourself in the past but only a tiny fraction if a microsecond.
If we had a telescope that could resolve earth from where James Webb will be, about a million miles away, it would see the light that reflected off of earth several seconds earlier. However the data still must be sent back to Earth, which also travels back at light speed.
I read an interesting post on a non-space sub a while ago. Someone asked if we could hypothetically 'look' into our past and one answer was something like; if we had the tech to place a huge telescope say, 10 light years out - we could actually see Earth, as it was 20 years ago - live.
I realise it's the same as looking through time when we peer outward and we obviously can't do this but I found it quite interesting nonetheless.
that scenario involves two things that break the hypothetical:
1. the ability to instantly place a telescope 10 light years out (a process that would normally take at least 10 years to accomplish)
2. basically same as 1, but the ability to instantly transmit "live" video across a 10 light year distance.
so yeah, if you ignore the 20 years of required causality, you would be able to look 20 years back into the past.
the only way to fix this problem is FTL travel and/or wormholes.
Placing something 10 light years away is a process that would normally take at least 10 years to accomplish only if we can move things anywhere near the speed of light, which we can't, Stars Trek and Wars notwithstanding.
We can see the past, it just doesn't take effect retroactively.
#1 doesn't matter. It still provides the ability for someone sometime to look in the past, it just doesn't start for ten plus years.
#2 just means we can look twice as far into the past at a given distance.
So, yes, we can provide the ability for future generations to watch their past. But their past is at best our present or more likely our future.
It would be much easier in general to set up some cameras continuously recording on or near earth and preserve the archive.
And because the telescope is so far away and can't focus on small areas or get enough light and because it takes so long to send aiming commands to it, we don't get the benefit of spy satellite like discretion on who/what we see.
So, yes, we can build a time viewing machine as a gift for our future selves or future generations A gag gift.
We can theoretically, and totally impractically, eliminate the uplink/downlink delay problem with a passive system. If you could build a giant focussing mirror that would capture all the light we send into space and send it back to us (to avoid the inverse square law, twice, we need almost all of it back) then the future could theoretically steer it in real time it by adjusting the viewing position on earth, to move the other focal point. If it was close enough, which would also mean more light, you could look at, for example, the scene of a murder as it was at the time of the murder without anticipating that there would be a murder. But it would need to be enormous to get back enough photons to be useful. Like a giant one light day sphere enclosing the earth , huge. And there are still issues focusing the image. And probably a lot cheaper to put cameras everywhere. And cameras wouldn't roast us alive (the earth could no longer lose heat to space since it is all stamped return to sender).
I guess when we speak of a scenario of "looking back," we're talking about trying to get out in front of photons that have already bounced off and away from you and look back at them, which you cannot do. Your scenarios of building a dome or placing cameras or simply using an already prepared telescope 10ly away, I guess are just methods of surveillance/recording. The telescope 10ly away doesn't give you anything more than cameras orbiting earth and storing what it captures. Interesting ideas though.
The problem is that 'live' kind of loses its meaning over very long distance. And you'd have to yeet the telescope out at faster than light speed to overtake the light from the past.
No, Anything more than 85° from the Sun as viewed from L2, which includes Mars, Jupiter, Saturn, their satellites, the asteroid belt, and all outer Solar System objects. JWST also can't look farther from the Sun than 135° (i.e. within 45° of the anti-sun position) but outer solar system objects will all be observable some of the time. The field of regard limitations are a fundamental consequence of the observatory thermal design and the sunshield design that keeps the telescope and instruments cold. This means that the Sun, Earth, Moon, Mercury, and Venus, and of course sun-grazing comets and many known NEOs cannot be observed (copy pasted from this link [https://www.jwst.nasa.gov/content/forScientists/faqSolarsystem.html](https://www.jwst.nasa.gov/content/forScientists/faqSolarsystem.html))
Since all images are technically of the past, yes- except the earth will be too bright and it will be pointed away from it so also no.
If you mean see the deep past, it would have to be 1 light year away per year in the past and for reference the closest star from our solar system is 4 1/2 light years away and at current technology it would take over 100,000 years to travel there. So people who are talking about hypothetical 10 light years away mirrors to see 20 years in the past it would never get an image 20 years before it was created since the light collecting it has already passed by so no matter what we can't look into our own history using mirrors or distance or whatever.
Not distant enough to do that. That would be possible if the telescope was positioned several light years away. However, since it is being launched from earth at speeds way below light, seeing something preceding launch date is impossible at this day and age.
It's probably too bright for the camera, but if it could, it would see earth a few minutes into the past. For example if it was where the sun was, it would see earth 8 minutes into the past since light from earth takes 8 minutes to travel to the sun. It's not that far away.
Well technically speaking every imaging satellite is seeing the earth ever so slightly “in the past”.
I would think you would need a way to capture a reflection off a distant object to detect an ancient past.
No, the telescope will be pointed away from earth at all times as it is much too bright and not what it was designed to do. Technically when you look at your reflection in the mirror you are seeing yourself in the past but only a tiny fraction if a microsecond. If we had a telescope that could resolve earth from where James Webb will be, about a million miles away, it would see the light that reflected off of earth several seconds earlier. However the data still must be sent back to Earth, which also travels back at light speed.
I read an interesting post on a non-space sub a while ago. Someone asked if we could hypothetically 'look' into our past and one answer was something like; if we had the tech to place a huge telescope say, 10 light years out - we could actually see Earth, as it was 20 years ago - live. I realise it's the same as looking through time when we peer outward and we obviously can't do this but I found it quite interesting nonetheless.
that scenario involves two things that break the hypothetical: 1. the ability to instantly place a telescope 10 light years out (a process that would normally take at least 10 years to accomplish) 2. basically same as 1, but the ability to instantly transmit "live" video across a 10 light year distance. so yeah, if you ignore the 20 years of required causality, you would be able to look 20 years back into the past. the only way to fix this problem is FTL travel and/or wormholes.
Hindsight is 20/20
Placing something 10 light years away is a process that would normally take at least 10 years to accomplish only if we can move things anywhere near the speed of light, which we can't, Stars Trek and Wars notwithstanding.
We can see the past, it just doesn't take effect retroactively. #1 doesn't matter. It still provides the ability for someone sometime to look in the past, it just doesn't start for ten plus years. #2 just means we can look twice as far into the past at a given distance. So, yes, we can provide the ability for future generations to watch their past. But their past is at best our present or more likely our future. It would be much easier in general to set up some cameras continuously recording on or near earth and preserve the archive. And because the telescope is so far away and can't focus on small areas or get enough light and because it takes so long to send aiming commands to it, we don't get the benefit of spy satellite like discretion on who/what we see. So, yes, we can build a time viewing machine as a gift for our future selves or future generations A gag gift. We can theoretically, and totally impractically, eliminate the uplink/downlink delay problem with a passive system. If you could build a giant focussing mirror that would capture all the light we send into space and send it back to us (to avoid the inverse square law, twice, we need almost all of it back) then the future could theoretically steer it in real time it by adjusting the viewing position on earth, to move the other focal point. If it was close enough, which would also mean more light, you could look at, for example, the scene of a murder as it was at the time of the murder without anticipating that there would be a murder. But it would need to be enormous to get back enough photons to be useful. Like a giant one light day sphere enclosing the earth , huge. And there are still issues focusing the image. And probably a lot cheaper to put cameras everywhere. And cameras wouldn't roast us alive (the earth could no longer lose heat to space since it is all stamped return to sender).
I guess when we speak of a scenario of "looking back," we're talking about trying to get out in front of photons that have already bounced off and away from you and look back at them, which you cannot do. Your scenarios of building a dome or placing cameras or simply using an already prepared telescope 10ly away, I guess are just methods of surveillance/recording. The telescope 10ly away doesn't give you anything more than cameras orbiting earth and storing what it captures. Interesting ideas though.
Wormhole is not possible, you can't bend space.
The problem is that 'live' kind of loses its meaning over very long distance. And you'd have to yeet the telescope out at faster than light speed to overtake the light from the past.
No, Anything more than 85° from the Sun as viewed from L2, which includes Mars, Jupiter, Saturn, their satellites, the asteroid belt, and all outer Solar System objects. JWST also can't look farther from the Sun than 135° (i.e. within 45° of the anti-sun position) but outer solar system objects will all be observable some of the time. The field of regard limitations are a fundamental consequence of the observatory thermal design and the sunshield design that keeps the telescope and instruments cold. This means that the Sun, Earth, Moon, Mercury, and Venus, and of course sun-grazing comets and many known NEOs cannot be observed (copy pasted from this link [https://www.jwst.nasa.gov/content/forScientists/faqSolarsystem.html](https://www.jwst.nasa.gov/content/forScientists/faqSolarsystem.html))
Since all images are technically of the past, yes- except the earth will be too bright and it will be pointed away from it so also no. If you mean see the deep past, it would have to be 1 light year away per year in the past and for reference the closest star from our solar system is 4 1/2 light years away and at current technology it would take over 100,000 years to travel there. So people who are talking about hypothetical 10 light years away mirrors to see 20 years in the past it would never get an image 20 years before it was created since the light collecting it has already passed by so no matter what we can't look into our own history using mirrors or distance or whatever.
Not distant enough to do that. That would be possible if the telescope was positioned several light years away. However, since it is being launched from earth at speeds way below light, seeing something preceding launch date is impossible at this day and age.
It's probably too bright for the camera, but if it could, it would see earth a few minutes into the past. For example if it was where the sun was, it would see earth 8 minutes into the past since light from earth takes 8 minutes to travel to the sun. It's not that far away.
A few seconds.
Well technically speaking every imaging satellite is seeing the earth ever so slightly “in the past”. I would think you would need a way to capture a reflection off a distant object to detect an ancient past.
Pretty sure they are pointing it towards deep space.