Everyday science

Does it take more effort to swim in the deep end of a pool than the shallow end? © Getty Images

Everyday science

Does it take more effort to swim in the deep end of a pool than the shallow end?

The platinum-iridium cylinder (right) was the primary standard kilogram for all metric measurements in the U. S. Known as Kilogram No. 20, it was a copy of the International Prototype Kilogram, which was preserved at the International Bureau of Weights and Measures at Sevres, France. Kilogram No. 4 (left, under double bell jar), a duplicate of No. 20, was used as a secondary standard. Noth cylinders were 39 mm in diameter and 39 mm. high; they were made of 90 percent platinum and 10 percent iridium. Re-comparison of Kilogram No. 20 with the international standard in 1937 showed that the United States standard had changed by only one part in 50 million during approximately 50 years.

Everyday science

A fond farewell to the humble kilo

What causes bath bombs to fizz? © Shutterstock

Everyday science

What causes bath bombs to fizz?

Why are some materials magnetic? © Getty Images

Everyday science

Why are some materials magnetic?

Does science have a problem with women?

Everyday science

Why aren’t there more women in science?

There's something inscrutable and mysterious about liquids © Getty Images

Everyday science

There’s something inscrutable and mysterious about liquids

© Marshmallow Laser Feast

Everyday science

What’s on at the British Science Festival 2018

How was the length of a second first calculated? © Getty Images

Everyday science

How was the length of a second first calculated?

A scene from the film 'Jack The Ripper', 1959. (Photo by Paramount/Getty Images)

Everyday science

Identifying Jack the Ripper: old clues, new science

Why does laundry smell better if it’s been hung up outside? © Getty Images

Everyday science

Why does laundry smell better if it’s been hung up outside?

Was maths invented or discovered? © Getty Images

Everyday science

Was maths invented or discovered?

Figure of a deer, moulded from electrum, dating back to the Thracian-Getan civilisation in the 4th Century BC © Getty Images

Everyday science

What colour metal would a gold and silver mix be?

Robert Hooke (Alamy) & Isaac Newton (Getty Images)

Everyday science

Who really discovered the law of gravity?

How do you get milk from nuts? © Getty Images

Everyday science

How do you get milk from nuts?