Re: When you put a spoon into water, what is it called?

Date: Mon Mar 20 02:41:47 2000
Posted By: Matthew B. Weyerich, Technical Coordinator,ES&R Dept., CPI Corp.
Area of science: Physics
ID: 952544070.Ph
Message:
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Hi there, Beth!

Really sorry to take so long getting this to you! My computer is having
trouble talking to other computers these days, so I don't always know if my
answer gets through. I keep trying, so, assuming this one does…

I think what you are referring to is called "refraction". That's a funny
word for light rays getting "bent" because they don't travel at the same
speed in water, glass, etc., as they do in empty space.

If light travels from a vacuum to another medium it gets "slowed down" by
electromagnetic interactions. The air-water mix we live in (not too dense,
so, still pretty much like a vacuum,) scatters and slows the light. Then,
however, the light hits a more dense thing, like clear glass. This slows it
down some compared to the rest of the light which doesn't hit the glass. We
mostly don't notice this. But…

When light goes from air, into glass, into water, through some more glass,
then out into the air again, finally striking our retinas, well, we notice
something odd!

Look at your glass of water with the spoon in it from the top. What do you
see?

The handle of the spoon looks bent! Is it, really?

No. What you're seeing is a "trick" called refraction. The light hitting
the spoon, then your eye, is different from the light which has to hit the
water, the spoon, more water, then your eye!

Another person asked me a similar question once. "Fishing" for the answer,
I decided to have a little fun. (Hope you do, too.)  Here is a link to my

the spoon looks bigger under the water (inside the glass) for the same
reason I mentioned above. (Refraction.)

(I THOUGHT I could prove this by plopping a spoon into a nifty clear wine
glass full of water. I THOUGHT I'd see different magnification as I rotated
the glass...knowing about refraction, as I do. Shows what I know! It all
looks the same to me! That spoon really does look bigger, doesn't it?!)

I still think my original response to your answer holds true, though.

You see, refraction is what makes lenses work. My glasses are lenses. So
are magnifying "glasses".

Our spoons are magnified by "lenses" made of water, glass, and air.
Refraction is what makes the lenses work! (It's not really an illusion.
It's really about how light REALLY works!)

If you want to get really technical, you can research "refraction", "index
of refraction", or, "Snell's Law" on your computer. (If you need a place to
start, check out the MadSci Search Engine.)

I hope this helps, Beth, and I hope you receive it! E-mail me if I can help
you more.
-Matt
mwnet@swbell.net

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