Looking at Raindrops up Close

Most recent answer: 10/22/2007

Q:
When you look through a large raindrop with your eye close to the surface,do you see things magnified? What if you stand back and look at a raindrop?
- Stephanie (age 12)
lakewood
A:
The answer is "probably yes, you can get raindrops to magnify images of close-by objects", but you’d have to get really really close to the raindrop and also put the object you’d like a magnified image of very close to the raindrop (or better yet, inside the raindrop). Raindrops are very small, and have tiny, tiny focal lengths. Nonetheless, they do act as converging lenses which are convex on both sides. You might not be able to get your eyes close enough to a tiny raindrop and keep things in focus, though.

If you put your eye farther away from the raindrop than the focal length, or look at faraway objects, the image will actually be smaller than looking at things directly, and will be inverted. You can try all of this with glass converging lenses, or, if you are so inclined, try a spherical glass paperweight, a round fishbowl, or other clear, spherical object (there’s a really nice quartz sphere in the Smithsonian Museum in Washington, DC).


Tom

(published on 10/22/2007)