How does light store and transfer HUGE amount of data yet it’s still the fastest thing in the universe?

Question

I’m not sure if I worded my question correctly, but let me try to explain more.

If we use a giant telescope to look at another planet 10 light years away from us, we would be looking at how it was 10 years ago. The thing I don’t understand is how does light store and also transfer all the information about that planet (or all the “data” that ends up in our eyes) and yet it’s still the fastest thing.

In: 94

Answer 1

It might help to understand that things moving at the speed of light do not experience time. This has the effect that light (effectively) does not change until it hits something. In the vacuum of interstellar space there is very little stuff for light to interact with. Therefore, by the time reaches us from distant places, it is almost exactly the way it was when it left that place.

If you have ever taken a long exposure picture, you are using the same principles that telescopes are using. There is very little light that reaches us from distant stars, so you have to collect light for a long time to get an image. Even then, you will only gather the light that reached the telescope. Astronomers use computers to process these long exposures to make the images that you see.

We use our understanding of physics to add more information than is immediately apparent. For instance, by finding the frequency bands of the light, we can tell which elements are emitting light. We can take pictures over time and figure out how fast and relative direction it is moving. We can take pictures at different wavelengths to get a more full understanding of its surroundings. We can use that information to determine how massive the object is.

The most ELI5 is probably to just imagine taking a picture of a candle from a mile away. Your camera is only going to capture what it is able to. You can get a better lens, enhance the image with software, take multiple pictures, and fill in the gaps with knowledge. You could probably tell how big the candle is, how big the flame is, and even how hot the candle burns. You still would not be able to capture every detail. But you can get pretty accurate.