There are more atoms in a single glass of water than there are glasses of water in all the world’s oceans combined — and if you marked every atom in one glass, dumped it into the sea, and waited for the oceans to mix completely, every glass of water on Earth would contain several thousand of those marked atoms

The arithmetic is one of the oldest and most reliable demonstrations in physics, and the conclusion is one of the harder facts about the size of atoms to actually believe. A standard 250-millilitre glass of water contains roughly 25 trillion trillion atoms, written as 2.5 × 10²⁵, accounting for the three atoms in each water […]

There is a region of space called the Boötes void, around 330 million light years wide and almost completely empty, and if our galaxy sat at its centre, we might not have discovered that other galaxies existed until well into the twentieth century.

In the direction of the constellation Boötes there is a roughly spherical region of space, around 330 million light-years across, in which almost nothing is found. It is called the Boötes Void, sometimes the Great Void, and it is one of the largest known empty regions in the observable universe. Its centre lies about 700 […]