End of the rainbow

PG · February 13, 2009, 03:41:46 PM

These are apparently the closest shots to the end of a rainbow ever taken. The article is pretty interesting too, I didn't know that rainbows moved very much but it was apparently moving at 30mph
http://www.dailymail.co.uk/news/article-1143482/Found-The-end-rainbow--theres-pot-gold.html

Mohawk20 · February 13, 2009, 05:19:51 PM

Of course rainbows move, their position is relative to your eyes or lens. The light you see is reflected in the rain, so if you move, you see light from different raindrops. Actually your eye is at the center of the rainbow, as below photograph shows. I took this in Scotland on the east coast late afternoon, looking towards the sea. You can see the rainbow (or circle in this case) has the shadow of my head as it's center.

It means the one that took the photograph was traveling at 30mph, and so the rainbow moved at the same speed.

mt_sabao · February 15, 2009, 04:24:23 AM

Or if you're standing still, the rainbow still moves as the sun 'moves' across the sky...

sjefen · February 15, 2009, 07:49:23 AM

Or maybe a giant raccoon comes along and eat's it all up

- Terje

Cyber-Angel · February 15, 2009, 08:25:40 AM

This is an interesting thread, and looking for a pot of gold (If this should ever come up in this thread in future) at the end of a rainbow is akin to seeking fame: talking of which one of the people in the Motion Picture Krull called Torquil said of fame "Fame is an empty purse. Count it and go broke. Eat it and go hungry. Seek it and go mad".

Regards to you.

Cyber-Angel

mhaze · February 15, 2009, 09:22:03 AM

Mohawk - I believe it's called a broken spectre.

Mick

PG · February 15, 2009, 12:18:04 PM

@Mohawk. what you're talking about is local light refraction, as mhaze said, brocken spectre http://en.wikipedia.org/wiki/Brocken_spectre. Rainbows are an entirely different thing.
http://en.wikipedia.org/wiki/Rainbow Rainbows move with the rain. Sure your perspective would change as well but the physical position of the rainbow you see from the first perspective isn't related to your movements.

Matt · March 06, 2009, 07:51:40 PM

And next week in the Daily Mail there will be an article about someone in California who took a video of his own shadow for half an hour, estimating that it moved at about 3 to 4 mph as he followed it...

Matt

buzzzzz1 · March 06, 2009, 08:07:34 PM

Quote from: Matt on March 06, 2009, 07:51:40 PM
And next week in the Daily Mail there will be an article about someone in California who took a video of his own shadow for half an hour, estimating that it moved at about 3 to 4 mph as he followed it...

Matt

Only in California! LOL

3DGuy · March 07, 2009, 08:20:14 PM

Quote from: PG on February 15, 2009, 12:18:04 PM
http://en.wikipedia.org/wiki/Rainbow Rainbows move with the rain. Sure your perspective would change as well but the physical position of the rainbow you see from the first perspective isn't related to your movements.

Err no. When you're looking at a rainbow the sun is always at your back. Rainbows do not move with the rain. They only move when you do (or the sun). It is not possible to view a rainbow from the side for instance which your comment would suggest. You are always between the sun and the rainbow.

PG · March 08, 2009, 05:16:30 AM

I didn't say you could. A rainbow isn't an object, like you said, it's just light that's reflected by rain. But rain doesn't fall in exactly the same place the whole time, as it move the drops reflecting the particular strands of light that cause you to see the rainbow move too, therefore, the rainbow moves.

3DGuy · March 08, 2009, 08:07:38 AM

Well, since the angle is pretty much fixed (around 40-42 degrees) the distance between you and the rainbow is also pretty much fixed. So the rainbow you're seeing is usually well within the area of rain, not the frontline. If the rain moves beyond this point, you no longer see the rainbow. So even if the raincloud moves, the rainbow itself is stationary.

Mohawk20 · March 08, 2009, 08:10:10 AM

The rainbow won't exactly move when the rain moves, but it will become bigger as the rain moves away from you.
To try it out, water your garden with a hose while standing with your back towards the sun. Then the rainbow is quite small because the water droplets are close by.

Since the rainbow is a projection of the sun through little lenses, the important parts are the observer (you) and the projectee (the sun). When you stand still and so does the sun, the only thing that will change the projection is the lens. If you move a magnifying glass toward the ground the projection gets smaller, moving it away makes it bigger.

But when the rain moves side to side, the only thing that changes is that you will see the same object (the sun) projected trough other lenses, roughly at the same position.

So the projection of the rainbow will not move, but it can change size...

PG · March 08, 2009, 01:11:07 PM

Yeah that sounds about right. I hope TG2 will be capable of this some day.

Mohawk20 · March 08, 2009, 06:09:34 PM

Quote from: PG on March 08, 2009, 01:11:07 PM
Yeah that sounds about right. I hope TG2 will be capable of this some day.

As do we all!!