We are all told that our head accounts for most of the heat lost from our body. But how much of this is true?
To find out, physiologists have submerged people in cold water. The people agreed to it, of course. They were given special drugs that stop them shivering, as this is the body's natural reaction to the cold. They were then lowered into the water. In some of the tests they were completely submerged. In others, only partially submerged.
They found that while the head accounts for approximately 8% of the body's surface area, it 'only' adds 10% of the body's loss of heat.
The Great Wall of China is often said to be the only man-made object that you can see from space.
The Great Wall of China is only just visible from Low Earth Orbit, but the distance from which it can be seen is often not specified. The distance from the Earth to the 'edge' of space is 62 miles, whereas the distance to the moon is approximately 237,000 miles. From this distance it would not be possible to see the Great Wall of China unaided.
From Low Earth Orbit, you can see many man-made objects, such as dams and cities.
Many of us are told that despite looking and feeling like a solid, glass is actually a vey slow moving liquid.
The 'evidence; for this is that some stained glass windows in churches are thicker at the bottom than at the top. They argue that this must mean that the glass has slowly flowed downwards over time.
However, this 'unevenness' is due to the process of making glass at that time, where it was thicker around the edges. They were then placed so that the heavier side was at the bottom.