16 Facts That Don't Sound Right But Are Actually True

That's according to an estimate from the Population Reference Bureau.

This is a consequence of Einstein's relativity, which states that time moves slower for objects experiencing higher gravity relative to those experiencing less gravity. Because your feet are closer to the center of Earth, they are experiencing a tiny bit more gravity than your head (if you are standing). It sounds crazy, but scientists have actually tested it with super accurate clocks.

The youngest known mammoth fossil is about 4000 years old and comes from Russia's Wrangell Island. This is around the time of the Old Babylonian period.

It's a dwarf planet-sized object with a beautiful name—V774104—and orbits, on average, 2-3 times further away than Pluto.

The end-Permian mass extinction, given the name "The Great Dying" by some scientists, occurred 250 million years ago and killed off around 90% of all species on Earth. Less than 5% of the ocean animal species survived and less than a third of large land animal species made it.

Dark energy (forces we cannot see) and dark matter (particles that do not interact with light) make up a vast majority of the stuff in space.

Harvard was founded in 1636. Calculus didn't make it onto the scene until Gottfried Leibniz's 1684 Nova Methodus and Isaac Newton's 1687 Principia.

During NASA's 1991 Spacelab Life Sciences (SLS-1) mission, jellyfish were placed in vials and bags of seawater, rocketed up to space, and chemically induced to breed while in orbit. This was all for science, of course. Turns out the space baby jellyfish looked pretty similar, but pretty much had jellyfish vertigo once back on Earth.

Thanks to thermal expansion!

It's from the moon! A rock sample from the Apollo 16 mission designated 67215c has been dated to be 4.46 billion years old. In contrast, the oldest bit of rock on Earth that we know of is a single crystal from Australia dated to be 4.374 billion years old, and thats not even a full blown rock.

The summit rocks of Everest are part of the Qomolangma Formation and are full marine fossils like trilobites. The rocks formed around 30 million years ago on the bottom of an ancient seafloor.

The basic gist is that the further back in your family tree you go, the fewer people there are to be related to, so more and more people begin sharing multiple ancestors. This is according to statistics and genetics. The ultimate conclusion is that everyone who was alive around thousand years ago (like Charlemagne) who has any descendants today (like Charlemagne) is an ancestor of every European.

Every time you fold your piece of paper, it doubles in thickness. Assuming a sheet of paper is 0.01cm thick, by the time you've folded it 20 times, it's 1048576 sheets of paper thick, or just over 100m. Fold it 42 times, and it's 4.4 x 10¹² sheets of paper thick, or 440,000 km – well over the (average) 384,000 km distance to the Moon.