January 23, 2010

Coldest temperature record – 1971

The record for coldest temperature in the U.S. occurred on this day in 1971, at Prospect Creek, Alaska. It was 80 degrees below zero, Fahrenheit (AKA 62 degrees below zero Celsius)! Brrr...




Cold-temperature records were set in other years, and other places, two weeks before and after this record-breaking low:

Jan. 25, 1902 - Japan -42 F / -41 C
Feb. 6, 1933 - Russia -90 F / -68 C
Jan. 27, 1944 - Netherlands -17 F / -27 C
Feb. 3, 1947 - Canada -81 F / -63 C
Feb. 2, 1956 - Spain -26 F / -32 C
Jan. 28, 1990 -- Finland -61 F / -52 C

To put all of that into perspective, the lowest temperature ever measured anywhere on earth was at Vostok Station in Antarctica, and it was -128.6 F (-89.2 C).

What Is Temperature, Anyway?

You probably know that temperature is a measurement of how hot or cold something is. However, what is it that makes something hotter or colder?

Let's talk about a chunk of ice. Even though a chunk of ice looks to us like it is just sitting there, motionless, all the molecules are vibrating a little bit. As the ice warms up, the molecules vibrate a little faster. When a part of the ice exceeds 32 degrees Fahrenheit, or 0 degrees Celsius, the molecules are moving quickly enough that that part of the ice melts and becomes liquid water.

If we continue to heat the ice until it all melts, the water molecules move enough to bump into each other a bit. Then, when we keep heating the water, the molecules continue to move faster and faster and bump into each other more and more often. Eventually the molecules move fast enough to change states again, this time evaporating, in other words becoming a gas (water vapor or steam).

Room Temperature

If you have a good quality thermometer, try to take readings of the temperature of a particular room. Take the temperature at eye-level, floor level, and just below the ceiling. Take it near an air vent, near a window or exterior door, and in the middle of the room. Does the temperature vary? Why or why not?

The saying is, heat rises. Do your temperature readings bear this out? Can you go somewhere even higher (a second floor, say) to check it out further? What other factors could affect the temperature on different floors of the same building?

Get Wise About Weather

This site has weather games and experiments.

There are games about reporting and predicting weather here.

Also on this date...

Anniversary of good stuff AND bad stuff for women in the sciences.

On this date in 1849, Elizabeth Blackwell graduated from Geneva College in New York first in her class, thus becoming the first woman to earn a medical degree in the U.S. It's said that Blackwell was only admitted to the college in the first place because people thought her application was a hoax, and neither professors and students were polite to her.

On this date in 1911, Marie Curie was turned down for France's Academy of Science—even though she was the first woman to win a Nobel prize and the first person to win two Nobel prizes! She remains one of only two people to ever win prizes in two different areas!

On this date in 1918, Gertrude Elion was born. She became an organic chemist and molecular biologist with a master's degree in chemistry. Elion researched the human immune system and developed medicines that would attack viruses and bacteria; she also created drugs to fight leukemia and to make kidney transplants safer. In 1988 Elion won a Nobel prize.

Go, girls!

Any girls out there might want to learn about some of the websites, camps, or organizations that support girls learning math and science. Start the hunt here or here or here.

November 27, 2009

Happy Birthday, Anders Celsius

Born on this date in 1701, Celsius was a Swedish astronomer who ended up immortalized because of the temperature scale he proposed. He made great efforts to very accurately measure the temperature of freezing water and of boiling water. He called the temperature at which water freezes 100, and the temperature at which it boils 0, and he then divided this amount into 100 small, equal steps (or “centigrade,” which is what he called his scale). He presented his scale to other scientists; for years, his thermometer was called the Swedish thermometer, although some used Celsius's term, centigrade. Now, of course, this scale is used worldwide in science and in many countries for all temperature measurements—and it is named after Celsius.


Did you catch what I said in the first paragraph?-- Celsius's system went from a low of 100 to a high of 0 !!!—so, when the temperature got hotter, it was going down! This was so counter-intuitive that, almost as soon as Celsius died at age 43, scientists reversed his scale. Now 0 degrees Celsius is the temperature at which water freezes, and 100 degrees Celsius is the boiling point.

Ahhh...much better!

(Of course, temperatures do get colder than 0 degrees C. (we use negative numbers for these measurements), and temperatures do get hotter than 100 degrees C., too.)

• Here is a simple algorithm to convert Fahrenheit to Celsius or vice versa:

First, whether your original temperature is Celsius or Fahrenheit, add 40.

Second, if you started with Fahrenheit, multiply by .55555 (a decimal point followed by 5 fives). If you started with Celsius, multiply by 1.8.

Third, subtract 40.

EXAMPLE:

(1) Start with 32 degrees F. Add 40. You will get 72.
(2) Multiply by .55555. You will get 39.9996. Round up to 40.
(3) Subtract 40. You get 0 degrees C. – which is correct.

THINGS TO DO:

A Celsius/Fahrenheit converter can be found here.

Activities and games about weather can be found here.