ScienceIQ.com

What Is High Blood Pressure?

High blood pressure is a blood pressure reading of 140/90 mmHg or higher. Both numbers are important. About one in every four American adults has high blood pressure. Once high blood pressure develops, it usually lasts a lifetime. The good news is that it can be treated and controlled. High blood pressure is called 'the silent killer' because it ...

Continue reading...

WhatIsHighBloodPressure
Physics

Earth's Magnetism

Most ancient civilizations were aware of the magnetic phenomenon. Sailors in the late thirteenth century used magnetized needles floating in water as primitive compasses to find their way on the sea. ... Continue reading

EarthsMagnetism
Biology

The Science of Tears

When was the last time you had a good cry? Shedding tears may be healthier than you thought, and the secret lies in the chemical composition of tears. ... Continue reading

ScienceOfTears
Biology

A Sweaty Subject

When human body temperature rises, tiny muscles around the sweat glands in the skin contract, squeezing perspiration - better known as sweat - out through the pores. Sweat is about 99 percent water. ... Continue reading

Sweat
Biology

The Great Permian Extinction

More than 250 million years ago, when the current continents formed a single land mass, known as the Pangea and there was one super-ocean called Panthalassa, something extraordinary happened. Nearly ... Continue reading

PermianExtinction

Ants Are Wimpy

AntsIt's common knowledge that ants can lift many times their own weight. We are frequently told they can lift 10, 20, or even 50 times their weight. It is most often stated something like this: an ant can lift over its head objects that weigh 20 times what the ant weighs. This is the equivalent of a 220 pound (100 kilogram) man lifting over 4,400 pounds (2000 kilograms) over his head! Seems incredible, doesn't it? That's like lifting a new VW Beetle, with five big men inside, over your head. A person who could do that would be a superman!

Are ants superstrong then? No. The reason they can lift so much more than they weigh is because they are very small. If we were that small, we could do it too. A small animal lifting many times its weight is not the same as a large animal lifting many times its weight. The reason has to do with simple geometry and the characteristics of muscles.

As an animal, or any object, grows in size, its volume and weight increase much faster than its height. If a 220 lb (100 kg) man were to grow ten times taller, his weight would increase by a factor of 1000 (the cube of his height). He would weigh 220,000 lbs (100,000 kg)! The strength of his muscles, on the other hand, would increase by the square of his height, or by a factor of 100. He would be 100 times stronger but 1000 times heavier. His muscle strength could never grow as fast as his weight. It's simple geometry. There is little reason, then, to compare the strength of small animals to big animals when it comes to how much more than their weight they can lift.