Looking into the past...

[Richie]

Okay, here's one for you.

In a purely scientific sense, I believe that we can all look into the past. More than that, I believe that we are constantly looking into the past without realising.

Can anyone guess why I think this?

[Fleech]

I assume the answer involves light and vision. I can't be arsed to word it properly, but if I'm right then you'll know what I mean. :P

[amplifiedAnt]

Spot on. Even though the speed of light is so great that we cannot conceive it, there is still a miniscule lag between what we see and what has happened. This of course increases with distance; for example, when we see stars, we are observing their state a long time previous to what we would call the 'present.'

[Haza103]

I don't understand what you mean by this :S

Sorry if i sound stupid, but do you mean like daydreaming looking at what you have just done? Or Do you mean like a past life sort of thing?

[impjim]

I don't understand what you mean by this :S

Sorry if i sound stupid, but do you mean like daydreaming looking at what you have just done? Or Do you mean like a past life sort of thing?

Well what it means is that when you look at a star in the sky, thr image you are seeing is millions (more or less depending how far away the star is) of years in the past. this is because it takes a very long time for the image of said star to reach earth.

So whatever is happening on that star right now is what we will see if we look at that star in however many years time.

this also works on earth as well but to a lesser extent. what you see when you look over the road is milli-seconds in the past becuase that is how long it has taken the image of that location to reach your eyes

[Richie]

Correct :D

Basically, for us to see anything, light must hit our eyes. When I see a spoon, light reflects from the spoon into my eyes, and that's how I see it.

Light has a speed, and although extremely fast, there is still a length of time involved for that light to get to my eye. In that time, a new image is being sent to me. Effectively at any point in time, the image being recieved by my eyes is actually an image of the past, as it's not the present image being sent.

You could work it out exactly. Light has a constant speed (distance/time) and you take the distance between your eyes and the object. From that you can work out the time it took for that image to reach your eyes and for you to see it, and that's how long you're looking into the past.

Obviously it's very little at short distances, but when you see a star at night, you are effectively looking thousands, in some cases millions of years into the past.

[Haza103]

Ah right i get ya, seems obvious now lol

[ardjoe]

Yes, the night sky has almost certainlly drastically changed as the current stars we are seeing are those that perhaps aren't around any more.

This thread also relates to the classic Mohammed Ali quote:
""I'm so fast I can turn the light off in my hotel room and be in bed before it gets dark.""

[Laika]

Red Shift ;) GCSE Physics, right there.

We really need to encourage this sort of delightful discussion and reflection more in the forum, it's great to see it becoming reasonably popular in the past week or so.

Here, here!

[RGL_UK]

Red Shift ;) GCSE Physics, right there.

We really need to encourage this sort of delightful discussion and reflection more in the forum, it's great to see it becoming reasonably popular in the past week or so.

Here, here!


Yea i agree.
I love the new debates that seem to be arising.
Let the games begin.

[vertigu9219]

Yep there has been some great topics raised in the serious discussion section over the last week or too, and a good deal of maturity and inteligence shown by most if not all who have contributed.
Its a credit to the community and a nice diversion from gaming.

[Chrisbes32]

Yep there has been some great topics raised in the serious discussion section over the last week or too, and a good deal of maturity and inteligence shown by most if not all who have contributed.
Its a credit to the community and a nice diversion from gaming.

A great deal of these have been posted by RGL, Well done to that man (Bar the purple type of course ;))