We often rely on scientific evidence to help us separate facts from fiction but sometimes science can just blow your mind.

People on Reddit are sharing scientific knowledge that appears to defy logic or common sense but are actually true – and here are a few of the best.

1. If you uncoil each strand of DNA in each cell of a human body and line them from end to end, it’d be long enough to stretch from the Sun to Pluto and back. – Kisaoda

Space Dna GIF by NASA - Find & Share on GIPHY

2. The human liver can be split in half and both sides will regenerate into fully functioning livers. I am alive thanks to this phenomenon, and thanks to my aunt who shared half her liver with me. – greffedufois

3. You replace every cell in your body every seven years. Thus, you are not the same person you were seven years ago. – Back2Bach

4. That 99.9999999% of your body is empty space. – Chinstrap_1

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5. There is more pizza in a single 18-inch pizza than there is in two 12-inch pizzas. – Codename_ZQ

6. The old adage “fake it till you make it” actually has behavioural science behind it. If you don’t feel confident, but act confident, eventually you will become confident – even if you didn’t believe it about yourself in the beginning. – slinky999

7. What burns longer: A rag or a rag soaked in gasoline? Most people pick the normal rag, because gasoline is a super flammable thing that bursts into flames and will burn things quickly. Nope! The rag with gas will burn longer. Because it has more fuel. – nagol93

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8. An AED machine (automated external defibrillator) is often depicted as restarting someone’s heart, but this is not the case. The only time an AED is useful is when the person is suffering from an erratic heartbeat because the electricity actually stops the heart from pumping in the hopes the cells regain normal function/rate. So in order to save someone in these states, you have to actually stop a very vital organ from functioning. – KyleRichXV

9. Your head ages faster than your feet. – liamemsa

10. When you glance at a ticking clock the second hand seems to hang for a moment, because your brain anticipates what you’re going to see faster than you actually see it. – BananaButton5

Clock GIF by Timeflies - Find & Share on GIPHY

11. Magenta doesn’t have a specific wavelength of light associated with it. It’s defined as the opposite of green. It’s your brain looking at an object and returning ‘I have no idea what colour that is but I know it isn’t green’, producing magenta. – lazing_in_the_welkin

12. If you pick 23 random people, there is a 50-50 chance, two of them share a birthday. Seems kind of crazy considering the 365 days of the year. – Berserker-Hamster.

13. The Moon looks larger at the horizon and smaller directly above. However, it is the same size, optically. – timojenbin