Monday, June 13, 2005
Stars twinkle, planets don't - why?
Question:
If you look up at the "stars" you'll see that almost all of them twinkle, but if you know which are the wandering "stars" - the planets, you'll notice that they don't twinkle. Why is that?
Hints:
Stars twinkle because the are so far away they are points of light. In other words, the photons of light come one after another in a straight line from the distant star or galaxy.
The planets are actually small disks of light so the light comes in parallel lines. If one of these 'lines' gets absorbed in the atmosphere there are still other 'lines' of light that can get through to your eye.
I suppose that there are some galaxies are big enough and close enough that they don't twinkle much either.
If you look up at the "stars" you'll see that almost all of them twinkle, but if you know which are the wandering "stars" - the planets, you'll notice that they don't twinkle. Why is that?
Hints:
- Twinkling is caused by the starlight interfearing with the atmosphere.
- Some of the starlight gets reflected, absorbed or bent by the atmosphere.
- The stars are very far away, the planets are not so far away.
Stars twinkle because the are so far away they are points of light. In other words, the photons of light come one after another in a straight line from the distant star or galaxy.
The planets are actually small disks of light so the light comes in parallel lines. If one of these 'lines' gets absorbed in the atmosphere there are still other 'lines' of light that can get through to your eye.
I suppose that there are some galaxies are big enough and close enough that they don't twinkle much either.
# posted by Scott Kirkwood @ 5:39 PM 
