Actor Alan Alda is challenging scientists once again to answer a basic
science question in language that will engage and enlighten
11-year-olds. He and the Stony Brook University Center for Communicating
Science have launched the second edition of the Flame Challenge.
The question for this year’s contest, selected from 300 submissions by
children, is: “What is time?” Scientists had until 1 March 2013 to
submit their answers in writing, video, or graphics. For more information on the contest, sponsored by AAAS (American Association for the Advancement of Science) and the American
Chemical Society, visit the Flame Challenge.
By the March 1 deadline, hundreds of scientists submitted answers for
this year’s Flame Challenge question: What is time? Thanks to all who
grappled with this tough question. We got entries from around the
globe, including England, China, Thailand, Australia, Japan, and Italy.
Now it’s up to our 11-year-old judges. Nearly 20,000 students will
judge the entries, including kids from Europe, Asia, Africa, Australia,
South America and 38 states in the U.S. So stay tuned – the winners
will be revealed at a special event at the World Science Festival on
June 2.
Note: All submissions were limited to only 300 words!
Scientists use the model of two-dimensional scientists, like
Dr. Rtwo, living on the surface of a balloon, to explain why there is no
preferred center of their universe and why expansion seems the same from any
location. Since we are
higher-dimensional beings, it is clear that they can't observe the third
dimension from their viewpoint, but
it is obvious to us from our
viewpoint.
Physicists are sure our universe is most likely
ten-dimensional, so let us invent an observer, Dr. Rten, who can see the entire
ten-dimensional universe. From Dr.
Rten's viewpoint, we are like Dr. Rtwo in his two-dimensional reality, crawling
on a three-dimensional subspace, unable to see the ten-dimensional
reality.
In our world, Dr. Rthree, with his three-dimensional
perspective, measures the speed of light to be a finite number, c. But this is measured from the viewpoint of
Dr. Rthree, and gives only the coordinate, or improper, speed of light.
Coordinate speed is the coordinate distance measured by the observer divided by the
coordinate time of the observer. Proper speed is the local proper distance divided by the local proper time.
Physicists all agree that as something approaches the speed of light,
its onboard clock slows down, until at light speed itself, the clock is
completely stopped. In the case of the
observer Dr. Rten, who is traveling with the photon, his local proper time is
always zero, so his proper speed is any distance divided by zero, or as Dr.
Rthree would call it, infinite.
What Dr. Rthree calls time is just an illusion caused by his
limited perspective, but is enormously useful in dealing with his reality. We could not function without this
illusion. It is this property which
"keeps everything from happening at once"! Understanding the mystery of time, then,
depends upon one's viewpoint.