Science: Technoquest

Thursday 19 August 1999 18:02 EDT
Comments

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

Q Why does a kettle go quiet just before it boils?

As water is heated, dissolved gasses in the water start to come out of solution. As water approaches boiling point all the dissolved gases have been released so there is no more bubbling. This is when the kettle goes quiet. As the water then begins to boil, the convection currents in the water become very violent and the water becomes noisy again.

Q Why doesn't lightning affect people inside a car?

There's a special effect in a hollow sphere of metal, called a Faraday Sphere, where there isn't any electricity inside the sphere. Faraday, the man who came up with lots of the rules on electricity which we now use, first found out that a hollow sphere has no electricity in it.

Q If a pineapple is a fruit, where are its seeds?

The pineapples eaten today are different from wild pineapples still found in some countries. A pineapple is a compound fruit - it is made up of several sections all stuck together to make one bigger fruit. Each section has its own seeds buried beneath the skin in sacks. If you peel a cultivated pineapple, you can sometimes see the vaguest hint of the seeds that a cultivated pineapple's "ancestors" would have had. In the past, someone must have found a pineapple without seeds that was managing to reproduce itself. This pineapple would have been produced accidentally by nature but, because there are no seeds, each pineapple has more fruit and is therefore more valuable to us. Farmers figured out that they could earn more by growing these types and so grew nothing else, so pineapples with seeds are now very rare.

Q What is hair made of?

Hair is made from cells called epithelial cells which are arranged in three layers. The innermost layer is the medulla, the middle layer is the cortex and the outer layer is the cuticle. The medulla is mainly soft keratin (a protein) and the cortex and cuticle are mainly hard keratin. This structure is very strong making a strand of hair tougher than an equally thick strand of nylon or copper wire.

You can visit the technoquest web site at http://www. sciencenet.org.uk

Questions and answers from Science Line's Dial-a-Scientist 0345 600444

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in