Brooklyn College
City University of New York

Science at a Distance

topic

Biological Energy

This Bio-Module requires the use of the text book "Exploring Life" by Professor John Blamire.

The Words of Science

calorie

The amount of energy needed to raise the temperature of one gram of water from 14.5 to 15.5 degrees centigrade (i.e. through one degree centigrade).

From the Latin calor.,heat Before 1857, most people believed that heat was a substance (like water or air) that could flow from one place to another. The Latin word for heat (calor) was used for this substance. But there was a problem first spotted by a scientist thrown out of America in the 1776 revolution. Benjamin Thompson noticed that friction (when drilling metal for cannons, for example) made two cold object (drill and cannon) hot. Where was the caloric (heat) coming from in this case?
In 1857, Rudolf Clausius first proposed that heat was, in fact, the energy of moving and vibrating molecules. So friction heated things up by making the drill and the cannon molecules move faster and faster. The idea stuck, but we still use the Latin word for heat in our definition of a calorie.


Words of Science