HOW DOES IT KNOW?
2006-08-22 05:38:22 · 14 answers · asked by RandomAsker 3 in Science & Mathematics ➔ Other - Science
they are the most clever things on earth dude
2006-08-22 20:23:10 · answer #1 · answered by Anonymous · 0⤊ 2⤋
This flask must have an insulating wall. Dewar flasks have a wall that encompasses a vacuum. Heat cannot cross a vacuum by conduction (although a little heat might escape by irradiation). Therefore, heat cannot leave a hot liquid in a Dewar flask; and heat cannot enter a cold liquid from the outside either. The flask does not have to know anything to provide this service.
2006-08-22 05:48:27 · answer #2 · answered by Art 3 · 2⤊ 0⤋
"Art" is correct. There is no magic involved, no microchips, no mystery. The flask has an inner container which holds the liquid, and an outer container which is it contact with the environment. In between is a vacuum. Since a vacuum cannot conduct heat (or cold) at all, it will be very efficient at keeping your liquid at the proper temperature.
2006-08-22 06:13:30 · answer #3 · answered by cutetom26 1 · 0⤊ 0⤋
The have microchips installed that tell them the liquid temperature and compare it to the ambient temperature. The chips where first used by NASA to provide tea for the astronaught on the first space mission and then later in commercial flights. Before then beetles where most commonly used in flasked to assist with this but weren't very effective.
2006-08-22 05:48:03 · answer #4 · answered by John D 3 · 0⤊ 0⤋
Its how the vacuum seal works. Inside is a silver lining. Silver is excellent for storing heat.
2006-08-22 05:47:58 · answer #5 · answered by lonely as a cloud 6 · 0⤊ 0⤋
It works on the same principle as most of the intellect shown on this site. How does it know - for the same reason you don't.
2006-08-22 06:54:15 · answer #6 · answered by charlie r 2 · 0⤊ 0⤋
It's one of the Great Mysteries of the Universe!!!
Cheers
2006-08-22 05:50:20 · answer #7 · answered by etnam90 4 · 0⤊ 0⤋
It doesn't need to know!
It prevents the flow of heat in either direction
2006-08-22 09:50:54 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Same reason as you know whether it is summer or winter (well, mostly, anyway!).
2006-08-22 05:55:50 · answer #9 · answered by Anonymous · 0⤊ 0⤋
david beckham bought one but his coffee melted his ice lolly !!
2006-08-22 05:46:22 · answer #10 · answered by Anonymous · 0⤊ 0⤋