Femtoinquiry ```Name: N/A Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A ``` Question: Do you have any lasers at Argonne? Please tell us what is a femtosecond. What can you tell us about quarks? Replies: 1. Yes there are lots of lasers at Argonne... lasers are very important in scientific research. They are also becoming important in electronics. Anybody who owns a CD player also owns a laser, since lasers are used to read the CD's. 2. Have you heard of the metric system? A millisecond is one thousandth of a second, a microsecond is one millionth of a second, and then successive thousandth's are: a nanosecond (a thousandth of a microsecond) a picosecond (a thousandth of a nanosecond) a femtosecond (a thousandth of a picosecond) So a femtosecond is 10^-15 of a second, and a femtometer is 10^-15 of a meter (also none as 1 fermi, the approximate size of the proton). 3. Quarks seem to be the most elementary particles we know about making up ordinary matter (in addition to electrons) - a proton has 3 quarks and a neutron also contains 3 quarks. The charges on the quarks are multiples of 1/3 the charge on the electron. Quarks come in 6 varieties, of which the last to be discovered was the "top" quark, just discovered this year, and which weighs as much on its own as a gold atom (which contains several hundred of the ordinary quarks). You should be able to find lots more information in the library - try Scientific American back issues. Arthur Smith Click here to return to the Physics Archives

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