BRAINDUMP
Amazing answers to your curious questions
When was the last ice age?
Ian Sanders
There’s been a series of ice ages over the past million years or so. Sometimes this whole period is referred to as the ‘ice age’, even though it has included many individual glacial periods that alternated every hundred thousand years or so, with warm periods called interglacials. More accurately, the last ice age refers to the most recent of these glacial episodes. This global descent into a cold climate started about 100,000 years ago and ended 11,700 years ago.
That whole period can be regarded as the last ice age, though it was also complex, with varying climates. The coldest part, when massive glaciers extended as far south as Britain, happened between 25,000 and 20,000 years ago; we call it the last glacial maximum. Past interglacials have been quite variable in length; so far ours has lasted 11,700 years. According to geophysicists, our interglacial still has several thousand years left to run, after which another ice age may well begin. However, human influence could change everything. The climate system is very complex and delicate, and global warming could hugely affect the onset of the next ice age.
WHAT IS AN APPENDIX?
Jerry Horton
The human appendix is a vestigial organ, which means that it has lost most, if not all, of its function due to evolution. In humans the appendix is a small remainder of the cecum, which our ancestors used to possess. In animals the cecum is still used to break down tough cellulose that’s found in plants. The appendix is located at the join between the large and small intestines and is a small tube with a closed end. If the open end of the tube becomes blocked, the appendix will swell and must be removed to prevent it from rupturing.
WHY IS SALT BAD FOR THE HEART?
Christopher Attwood
Too much salt is bad for you as it increases the demand on your heart to pump blood around the body. This is because when you eat salt it causes the body to retain water, which increases your blood pressure, and this places more strain on your heart.
Did you know?
An appendectomy is the name for when the appendix is removed
HOW DO REWRITABLE CDS WORK?
Ben Swindell
A normal CD has a surface covered in microscopic bumps – abump will signify a ‘zero’ and a flat will signify a ‘one’ in the binary system, and this is how data is read. This has to be different for a rewritable disc though. For this, a dye is used to coat the surface. When writing on the CD, the dye will either be opaque or clear, with the two states representing the binary number system. The dye is designed to change between opaque and clear so the disc can be rewritten several times.