67 mind-blowing facts you’ll think are made up (but aren’t)

Premenstrual syndrome – the collection of symptoms that hit women in the week or so before their menstrual cycle starts – is the butt of many jokes. But men should stop chuckling as medicine recognises the male equivalent called “irritable male syndrome,” a behavioural state defined as “hypersensitivity, frustration, anxiety and anger that occurs in males and is associated with biochemical changes, hormonal fluctuations, stress and loss of male identity.”

Here are 20 obscure facts you never knew about your own body. 

The Earth’s speed as it orbits the sun is not a fixed rate. No matter how constant it may seem to us mortals, it’s actually slowing over time. The length of a day will become 25 hours…in about 175 million years. So don’t toss your clocks just yet.

Raspberries, strawberries and blackberries aren’t true berries. The scientific definition of “berry” is a plant that has three distinct layers: an outer skin (exocarp), a fleshy middle (mesocarp), and – here’s the key – internally contained seeds (endocarp). So because their seeds are on the outside, all those berries aren’t actually berries. However, watermelon, bananas, grapes and eggplants are all technically berries!

Don’t get excited yet Flat Earthers – the planet we all call home isn’t flat but it’s not round either. Technically the Earth is known as an “oblate spheroid” due to the bulge at the equator and the flattened poles.

Don’t miss these 24 amazing facts you didn’t know about NASA. 

Many people think cuddling this adorable cross between a duck and an otter would be fun. But beware to the person who tries it! The duck-billed platypus has poison glands in its hind legs and can release the venom using a hollow spur on its heel. While generally not deadly, the sting is said to be incredibly painful and causes a large amount of swelling.

Discover more amazing animal facts you probably didn’t know. 

The speed of sound is 343 metres/second. But a bullet fired from a rifle travels at 762 metres/second. This means that if you’re ever targeted by an expert marksman you’ll be dead before you hear the gunshot. Which is comforting? We guess?

London may be one of the largest metropolises in the world but when it comes to actual people, only 9,000 reside in the City of London. The city is a small area surrounded by the Greater London region – which has 8.1 million people.

There are about 3 trillion trees on Earth but only 300 to 400 billion stars in the Milky Way. Space is big but relatively empty, it turns out.

Learn about 11 places on Earth that are still unmapped. 

Polar bears may be known as being so white they can hide in snow but the truth is they aren’t white at all. Their skin is black and the hairs in their fur are hollow and clear. So why do they look white? Light hits their fur and is trapped inside the hollow part of the hair, causing a reaction called luminescence. In addition, salt particles stick to the bears’ fur and act as light-scattering particles.

Rhubarb doesn’t get a lot of love (unless it’s in a pie) but the stalky plant does have an amazing talent: It grows so fast you can actually hear it. Listen for yourself.