Electric toothbrushes contain an electric motor – which is made to turn by the electricity from the battery inducing a magnetic field. The motor contains a commutator and some brushes, which are usually made of carbon. As the motor rotates, it intermittently connects with the brushes, and this leads to an intermittent current which then makes a spark. This effectively means that your electric toothbrush generates radio waves across a wide range of frequencies, which will affect anything nearby that is sensitive to radio waves, such as your TV or your radio.

Another reason for what looks like a wobbly picture when watching TV and using an electric toothbrush is the vibrations caused to your skull and eyes.  This may only effect a TV because it’s scanned at a certain frequency (25Hz), so everything else would not appear wobbly!

The main reason is that when cooking from a recipe, or following the instructions on pre-packaged food, there is a recommended time that the food needs to be cooked at the right temperature in order to be cooked properly and safe to eat. If the oven hasn’t reached that temperature yet, you may be cooking it for the wrong length of time.

There are lots of chemical reactions occurring when you cook food, and different reactions occur at different rates depending on the temperature. This means that while your food is in the oven below the right temperature, you will not get the right balance of reactions occurring while you cook.

The reactions which give food it’s distinctive ‘cooked’ flavours and colours are Maillard reactions (between sugars and amino acids) and caramelisation (the oxidation of sugars). These reactions work better at higher temperatures, and so your food will look and taste better if you wait for the oven to heat up.

Also, while the food is pre-heating it will be losing water by evaporation, meaning that the cooked meal is likely to be drier and less succulent.

[We put this question to David Thomas, author of ‘Surviving Antarctica’]

Because your eyeball is contained within your head, and your head is kept at body temperature, it never gets cold enough to freeze.  The eyeballs in a dead body would indeed freeze, but while you’re alive and radiating heat it can’t.  Even tears wont freeze immediately, as they are very salty, and salt reduces the freezing point.

All animals control their blood pressure to an extent, but giraffes have a special adaptation consisting of a series of valves in their neck to control the intense pressure that would build up when they put their head down to drink.  This anatomical adaptation controls the blood pressure otherwise they would have a massive surge of blood into their brain and experience ‘red-out’.

This is an example of adaptation.  Everything in the nervous system is adaptable, which means that when you smell something or feel something, get into a hot bath for example, you stop noticing the sensation after a while.  Your eyes are exactly the same.  If you stare at something for a while without moving your eyes around to refresh the image, the retina degrades the image and it becomes blurry.  That’s true of anything you look at, and as rainbows are slightly less distinct, it’s more difficult for the eye to get a fix on it, and so they probably degrade more easily.