Did you know that sharks are older than trees?
The earliest evidence of shark scales dates back about 450 million years. Meanwhile, the earliest species that scientists officially classify as a "tree" (Archaeopteris) didn’t show up until about 350 million years ago.
That means sharks had a 100-million-year head start on trees—and they've survived four of the "Big Five" mass extinction events, including the one that wiped out the dinosaurs.
Just in case you already knew that one, here are three quick backups:
- You can hear the difference between hot and cold water. If you pour them, they make different sounds. Cold water has a higher viscosity (it's "thicker"), which causes it to bubble and splash at a lower pitch than hot water. Try it next time you make coffee or tea—most people can guess the temperature with their eyes closed just by listening to the pour.
- Mammoths were still alive when the Great Pyramid was being built. While the ancient Egyptians were constructing the Great Pyramid of Giza around 2560 BCE, a small population of woolly mammoths was still roaming around on Wrangel Island in the Arctic Ocean. They didn't go fully extinct until about 1650 BCE.
- Nintendo was founded the same year the Eiffel Tower was built—and Jack the Ripper was still on the loose. Nintendo started in 1889 in Kyoto, Japan, not as a video game company, but as a manufacturer of handmade Hanafuda playing cards.
Did any of those catch you off guard?
When you move your eyes from one object to another, you actually go temporarily blind.
These rapid eye movements are called saccades, and your brain intentionally shuts down visual processing during them so the world doesn't look like a nauseating, blurry streak.
Instead of letting you see the darkness, your brain does something called chronostasis: it takes the image of the thing you end up looking at and "backdates" it in your memory to fill in the gap.
You can actually see this happening right now: if you look in a mirror and shift your gaze from your left eye to your right eye, you will never see your own eyes move. (However, if you record a video of yourself doing it, or watch someone else do it, the movement is completely obvious).
In total, your brain edits out about 40 minutes of blindness every single day without you ever realizing it.
Mammoths were still walking the Earth when the Great Pyramid of Giza was being built.
While most of the world's woolly mammoths went extinct around 10,000 years ago at the end of the last Ice Age, a small, isolated population survived on Wrangel Island in the Arctic Ocean.
Because there were no humans or predators on the island, this group of "dwarf" mammoths thrived for thousands of years longer than their mainland relatives. They didn't finally go extinct until around 1650 BC.
To put that in perspective: The Great Pyramid of Giza was completed around 2560 BC. This means that when the pyramids were already nearly 1,000 years old, there were still living, breathing mammoths on the planet.