Probably all, or nearly all, who have experienced a cold winter, are familiar with the cheery cry of the snow as it is pressed against a hard surface by the steel tire of a wagon, for instance, or even onto a pavement by the heels of ones boots. Thos...
If you ever had a paper route or any other job that took you through a series of streets, you may have spent some time working out the quickest way to complete the circuit. In order to cover your route most efficiently, you would want to avoid going...
In the 1700s the Swiss-born mathematician, Leonhard Euler worked out a way to tell whether or not a particular design was traceable in this way simply by counting the number of lines at each intersection in the design. He found that if all the inters...
The Oort cloud is a spherical haze of comets that surrounds our entire solar system. We often get the false impression that the solar system ends with Pluto. In fact, beyond Pluto is the Oort cloud, encircling everything else like an enormous shell....
A skydivers body is in a delicate balance. Gravity tugs her downward with a constant, relentless force, while air resistance pushes her upward. The faster she falls, the more air resistance there is, so eventually these two forces cancel out. Then sh...
Snowflakes are small ice crystals. Snowflakes near their melting temperature can, through hand pressure, be made to fuse into a snowball by a process of melting and re-freezing. The snow yields to pressure gently and progressively and doesnt make sou...
Maintain a balanced diet. Get plenty of exercise. Cut down on junk food. All are basic tenets of living a healthy lifestyle. And for good reason. Exercising regularly can help control weight gain. And theres evidence that being physically active can...
You might wonder about the chemicals other function thoughto attract more pike. A minnows skin is most likely to be damaged in an attack from a relatively small pike. Larger pike simply swallow their minnows whole. Because of this, the alarm substanc...
M:We're very kind of self-conscious about class aren't we and we don't like to, if you're rich, you don't like to act like a rich person. People don't like to show what class they're in do they? Finn: I think that the divisions, yes, are perhaps more...
M:OK Derm, thanks very much for coming along today and I'm sorry if we've upset you. Diarmuid: No no I'm fine, I'm fine. But I'm still not telling you. Ok bye bye. W:Thank you, thank you for joining us. M:See you. Diarmuid: Bye bye. M:Do you think we...
To make an airplane contrail, you need water and some kind of microscopic particle for the water to condense around. When jet fuel burns, it releases both water vapor and microscopic particles of exhaust. A contrail occurs when the jets water vapor c...
Beneath the surface of a pond or stream its a fish-eat-fish world, and the tiny minnow is often lunch for larger fish such as pike. Youd think a tasty minnow would try to remain inconspicuous, but this isnt always the case. If a minnows skin is damag...
Have you ever seen a perfectly cloudless sky? Cloudlessthat isexcept for two or three long white lines smeared across the perfect blue sky by airplanes like smudges on a pane of glass. Why do airplanes sometimes leave contrails behind? Actually, cont...
Thats because the belly on a starving person has nothing to do with fat. Rather, it is often the result of Protein Calorie Malnutrition, or PCM. PCM means a healthy number of calories are being eaten say in the form of rice but with a severe deficien...
This is because whenever a sound wave moves suddenly from a narrow space to a more open one, some of the sound is reflected backward. This is exactly what happens when the sound of your voice moves from the narrow confines of your mouth into the wide...
