Theoretically if I was 66 million light years away from earth and had a telescope strong enough would I be able to see the dinosaurs if I faced it towards earth and nothing was obstructing my view?
In: Physics
Yes. It would have to be an absolutely colossal telescope – as in completely impossible, but theoretically, yes, you could.
If the telescope was more powerful than anything we can create using our current knowledge of material science and physics, then yes. It sounds absolutely crazy, but it’s true. You would see 66 million years into the past, because the light from earth that you can see will be that old.
No. Lenses have a limit of resolution based on the size of the wavelength of the electromagnetic spectrum they are observing. That’s why light microscopes can’t see individual atoms but electron microscopes can (big atoms, anyway). The same problem comes into play with telescopes. At 66 million light years distance, there is a limit of resolution that is never going to see dinosaurs on Earth because the angle is too small for the wavelengths of light to resolve that image.
You might get around that using a large array telescope. But the array would need to be ridiculously huge.
I totally expect people to be able to see into the past, eventually, in similar way that OP describes. That includes intercepting the light that gets reflected back to us from somewhere in deep space, or phoning a far away civilisation and asking them what they see/saw.
“Yes”.
This sub requires longer answers but you’ve basically asked a yes-or-no question, so here we are.
* 67 light years: 6×10^(17) m
* minimum resolution to see a dinosaur: 1 m
* wavelength of visible light: 5×10^(−7) m
Multiplying and dividing gives a minimum telescope diameter of 300 million km.
To clarify a bit more, photons (light particles) are limited by the speed of light. A light-year is the distance light can travel in a vacuum. We see by light reflecting off of objects and into our eyes. If you were 66 million miles away, only the light that reflected off the Earth 66 million years ago would have had the time to travel across the galaxy and reach you.
That is why, yes, you’d be seeing an image of Earth (and dinosaurs) from 66 million years ago if you were that far away.
So we could send a telescope to whatever distance is required (today would be 1,993 light years) to view Saturday April 28th 31 AD and have that telescope stare at this grid coordinate 31.7794, 35.2320 and see this whole resurrection thing go down
The problem is, how long would it take you to get 66 million light years away from Earth? At minimum, 66 million years. So by the time you go there, “66 million years in the past” would be today
Yes.
Imagine this:
* On Monday I take a Polaroid photograph of a house. I put that in an envelope and post it to you.
* On Tuesday the house is knocked down.
* On Wednesday you receive my envelope and you see the picture of the house
* Even though the image literally just reached you, you are seeing something from the past that no longer exists.
Thats what would happen with your telescope.
Because of the time it takes for the image to travel to you, you are seeing the past.
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