If Voyager 1 took a picture of the earth, what year would it be?

Question

Can a camera placed a light year away from the earth capture time waves of light?
If energy is never destroyed and light is energy, then light waves from the past are still traveling in space. It is a matter of placing the camera at the proper distance from the earth. What is this distance and when will Voyager 1 be at this distance? Say We wanted to capture the light energy from the night of Trayvon was killed, What distance from Planet Earth would a camera have to be placed to capture the light energy in that wave and how that wave of light be converted into a picture?

Answer 1

If Voyager took a picture of Earth now it would see it as it was 17 hours ago. To get to a distance of 1 light year away will take:



voyager1 is travelling at 62,136 km/h

1 light year is 9.4605284 × 10^12 Kilometres



9.4605284 × 10^12 km/ 62,136 km/h = 1.5225519×10^8 hours



There are 24 hours in a day and 365.25 days in a year so :



1.5225519×10^8 hours / (24*365.25) = 17,369 years



So in 17,369 years time, voyager 1 could take a picture of Earth as it was 1 year before it took the picture, that is to say in 17,369 years' time you could look back and see our Sun looking like a single dot but that single dot will be made from the light that left the Sun 17,368 years ago. Even today if you turned Voyager 1 around and took a picture of Earth it would be just a pale blue dot - a single blue pixel much further and Earth will not even be detectable to Voyager 1's camera.



Okay that's the actual answers to your question but it's not helping you understand the principle.



The speed of light is finite (no time waves or anything like that) it just takes a finite amount of time to travel a distance. So if you are looking at a star 4.5 light years away you're seeing it as it was 4.5 years ago simply because it took the light hitting your eyes 4.5 years to make the long journey.



Think of it this way, light is an information carrier (think of a carrier pigeon carrying a message) each photon of light is a carrier pigeon carrying a single pixel of information (the colour of the thing it bounced off), those carrier pigeons fly at a set speed, they can't increase or decrease in speed until they reach their destination (your eyes), so if you are 1 light year away it takes those carrier pigeon photons 1 year to fly all the way to your camera. Not because they're tunnelling through time.



Now if you launch a super camera which takes 17,000 years in 2013 so it is set up 1 light year away and looks back on Earth it won't be seeing Earth as it was in 2012, it will see Earth as it was in the year 17,000+2013 -1.



Now if we already had the camera there and we only had to tell the camera to take a picture of Earth, it would take 1 year for the signal to get to the camera, the camera would take the picture and transmit the picture back to Earth which would take 1 year to arrive. Thus if in 2013 I asked the camera to take a picture of Earth, The camera would take the picture of Earth as it was in 2013 in the year 2014 and I would get the picture of Earth as it was in 2013 in the year 2015.



If you wanted to see how things look in the past, the cheapest and most viable option is to simply record the images from all the millions of cameras already on the planet taking pictures of things on the planet. True there are photons carrying the images of Trayvon being killed somewhere out there in space but by now they are so diffuse it would be really hard to assemble them into an image and no mass can reach or exceed the speed of light - so that information is lost to us, whizzing off into the universe forever out of reach unless we can invent some sort of FTL technology like warp drive but that is pure speculation.

Answer 2

Voyager 1 is presently a little over 17 light-hours away from Earth.

Radio waves are electromagnetic radiation like light waves and also travel at the speed of light.

Thus basically every day Voyager 1 is picking up 17-hour-old transmissions beamed to it from Earth.

The general noise from Earth is way too weak for Voyager's receiver to collect, it is lost in the overall noise. Only the signal beamed in Voyager's direction by the large antennae of the Deep Space Tracking Network is powerful enough for Voyager's receiver to collect a useful signal.

It has taken Voyager 1 36 years to get to that distance. It will take 20,000 years for Voyager 1 to get to a distance of 1 light year from Earth.

Answer 3

Voyager 1 is only 17 light hours away. It would need a giant telescope to see so small a detail as Trayvon's death, perhaps a telescope as large as Jupiter or even larger as the light would be really spread out. Even if it were a light year way and had a giant telescope, when you radio it the command to take the picture, that command would also travel at the speed of light and therefore would arrive too late to take the picture. You only have the evidence presented at the trial, there is no miraculous way to replay time.

Answer 4

A camera 1 light year from Earth would see images that left Earth 1 year before. So that camera would see an image of the Earth as of July 2012.



To see February 2012 it would have to be about 1.42 light years from Earth (since Feb 2012 was 1.42 years ago).

Answer 5

Chaos, quantum and dust render images unreadable.

The definition (smallest thing seeable) of an image taker depends on the size. We can just about make out the fact that a planet has crossed the face of a distant star.