Drink in the Taste of the Universe: The Cosmic Latte

What colour do you think the universe is? Black, perhaps? Blue? Or maybe something rather more surprising – cosmic latte!

Cosmic latte is the name given to the average colour of all the visible light produced by stars and galaxies. And despite sounding like something you might order at your local coffee machine, it is actually a very pale, creamy beige – remarkably similar to a milky cup of coffee.

The colour was worked out in 2002 by astronomers Karl Glazebrook and Ivan Baldry, who studied the light coming from more than 200,000 galaxies. Their first calculations suggested the universe was slightly turquoise, but they later discovered a small error in their measurements. Once corrected, the cosmic colour turned out to be a much warmer shade.

Of course, this doesn’t mean that space itself is beige. Look up at the night sky and most of it appears black because space is incredibly empty. Cosmic latte is an average – a mathematical way of combining the light from the countless stars and galaxies that make up our observable universe.

Interestingly, the universe’s average colour hasn’t always been the same. Billions of years ago, when there were more young, hot, blue stars, it would have looked somewhat bluer. As the universe ages, the balance is gradually shifting towards warmer colours.

So, the next time you take a break for a nice cup of coffee, spare a thought for the cosmos. You might just be drinking something remarkably close to the average colour of the universe!