Dear Mr. Scientist: How can there be such a thing as seedless grapes? I thought plants come from seeds, so how do these things grow?
Seedless grapes are possible because of a technique in which part of a grapevine is cut off and placed in the soil. Roots sprout from where the vine was cut, and soon the small piece of a plant becomes its own full-fledged grapevine. This newly formed vine is a clone of the original. As for the first seedless grapevine from which all modern day vines come from, its origin isn't yet known. The most popular theory is that thousands of years ago, a vine in the Middle East suffered a genetic mutation called stenospermocarpy, causing the hard seed casing to fail to develop which some bright farmer took advantage of.
Dear Mr. Scientist: I've been thinking about getting one of those radar detectors to avoid getting any more tickets. How exactly do they work?
Ideally, when using a radar gun the signal goes from the gun, bounces off the car and goes back to the gun. In reality, some of the signal misses the car or bounces around and never makes it back to the gun. These signals that leaked are the ones a radar detector can pick up. The signal that comes out of a police officer's radar gun are radio waves and are no different than the AM or FM waves your car stereo picks up, so in essence a radar detector works just like the radio.
Mr. Scientist is Michael Leitch. If you have a burning science question you want him to answer, send en e-mail to firstname.lastname@example.org.