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.
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.
