ScienceIQ.com

The Physics of Sandcastles

Give a plastic bucket and a shovel to a child, then turn her loose on a beach full of sand. She'll happily toil the day away building the sandcastle to end all sandcastles. It's pure fun. It's also serious physics. Sandcastles are built from grains - billions of tiny sharp-edged particles that rub and tumble together. The strength of a sandcastle ...

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Sandcastles
Engineering

Sundials, Ancient Clocks

The earliest and simplest form of sundial is the shadow stick. The time of day is judged by the length and position of the stick's shadow. Some nomadic peoples still use this method for timekeeping. ... Continue reading

SundialsAncientClocks
Biology

How Biological Clocks Work

Anyone who has traveled has experienced jet lag—that groggy realization that while your day is beginning in Washington, DC, the night you just left in San Francisco is hardly over. Jet lag is an ... Continue reading

HowBiologicalClocksWork
Biology

Vitreous Humor, Sclera and Other Yukky Eye Stuff

Eyes are one of the most complex organs humans have. In fact the optic nerve connection to the brain is so complex and delicate that no one has ever succeeded in transplanting the whole eye (the ... Continue reading

HumanEye
Astronomy

Rossi X-ray Timing Explorer Solves Mystery of Pulsar 'Speed Limit'

Gravitational radiation, ripples in the fabric of space predicted by Albert Einstein, may serve as a cosmic traffic enforcer, protecting reckless pulsars from spinning too fast and blowing apart, ... Continue reading

RossiXrayTimingExplorer

Take Two And Call Me In The Morning

AspirinAspirin has been used for hundreds of years to relieve pain and reduce inflammation. It belongs to a group of chemicals called salicylates and was originally derived from the bark of the willow tree. But how does aspirin work? When you fall down and scrape your knees, how does it know that it needs to go down to your legs? When you bruise an elbow, how does it know where to go to fix that pain?

First let us understand what happens when you get hurt in a fall. Your skin is covered with tiny nerve endings. Each is a little sensor that detects pressure, pain and heat. All these nerve endings communicate what they sense back to the brain. They do this by releasing chemical signals which are sent to the brain. When a nerve touches something lightly, the signal is not very strong. When you apply pressure or damage the nerve ending, it sends out a much stronger signal. Aspirin simply inhibits the release of the chemical, called prostaglandin, that creates the signal that our brains interpret as pain. In a way, the pain is still there, we just feel it less.

To answer our earlier question, aspirin doesn't really have any idea where to go to relieve the pain. When you swallow an aspirin it quickly gets into your bloodstream and travels throughout your body. If it finds a nerve ending that is generating prostaglandin, it interferes with its production. Something to consider is that while painkiller can reduce what your brain feels, you are still hurt. It doesn't automatically make your grazed knee better!