The goal of science is to help us make sense of what surrounds us, but it can also lead to mind-blowing moments that shake us to our very core. From history and timekeeping to biology and the human body, we often need to take a moment to reassess facts about the world. So enjoy this whirlwind tour of facts that might give you an existential crisis.
Time is confusing
Humans as a species tend to be focused on ourselves, so our sense of “time” and “history” is nebulous at best. We don’t exactly picture how events further in the past happened at different times. In general, we can’t keep everything in our mind in the right proportion.
If the whole history of our planet is compressed into a 12-hour period, Homo sapiens only show up at 11:59:58. And even this is not as indicative of time spans from the past. So let’s look at some examples. The T-rex lived closer in time to us than to the Stegosaurs. Cleopatra was closer to a Taylor Swift concert than to the construction of the Great Pyramid of Giza. And on the subject of pyramids, when the first ones were built, woolly mammoths still roamed the Earth. Seriously! France was still executing people by guillotine when Star Wars came out.
And it’s not just that. We often feel like positive events in time are closer to us than they are, while bad events are far away. Laws allowing slavery in America are not something from the distant past. In fact, there are people alive today whose grandparents lived before the Civil War, such as the grandsons of President John Tyler. We also often think of the height of the space race as recent, but it has been 46 years since any human has actually left low-Earth orbit. We are but a blink in the cosmic clock.
Space is big
It’s not our fault that we are bad at grasping the reality of vast things. We are, after all, apes evolved to live in the Savannah. History is obviously wide and puzzling, but space is also quite complicated for us. We often fail to grasp just how big our planet is, let alone the cosmos. Around 71 percent of the surface of the Earth is covered in water and less than 5 percent is estimated to have been seen by human eyes.
The Earth is also relatively smooth when considered as a whole. Not as smooth as a billiard ball, but its highest and lowest points (Mount Everest and the Mariana Trench) are just a very small variation of the planet’s radius, which is almost 6,400 kilometers (about 4,000 miles). The size of the Earth is clear, so let’s now move from the Earth to the Moon, our closest celestial companion.
The moon is about 380,000 kilometers (236,000 miles) from us, and it would take over 8.5 years for a human to continuously “walk” that distance. But let’s speed things up. The record for the fastest spacecraft is held by the Helios 2, which reached speeds of 98,900 meters per second (221,233 miles per hour). Quite the speed, uh? It would only take 40 seconds to go from LA to New York at that speed, and yet it would take over 12 hours to circle the Sun’s equator.
Even at that neck-breaking speed, it would take 11 days to get to Mars. Now let’s go crazy and multiply that speed by 100. Well, it would take you about 21 days to get to the edge of the Solar System and about 129 years to reach the closest star to the Sun. And even after you have spent all that time, you still have crossed only an insignificant part of the universe.
Super-size is super-scary
Speaking of the universe, another terrifying fact is how big things are in space. Sure planets are big and stars are bigger, but when you actually think just how big they are, you can appreciate just how insignificant we really are. The biggest star is currently believed to be UY Scuti, which has an estimated volume of 21 billion times that of our Sun and extends to almost the orbit of Saturn if placed in our Solar System. Yet, the universe has bigger and even more terrifying objects in store for us.
Supermassive black holes are millions, if not billions, of times the mass of our Sun, which is already pretty heavy. While regular black holes pack their huge mass into a tiny volume not much bigger than a city, the heaviest black holes are terrifyingly huge. The biggest estimated black hole would have a radius of 62 billion kilometers (38.5 billion miles) – enough to dwarf the Solar System.
At the end of the day, black holes are not as scary as we might feel. If you need to be worried about something, supernovae are the ticket. If you were looking at a supernova the same distance from you as our Sun, your retinas would receive light equivalent to a billion hydrogen bombs detonated directly on your eyeball. At least it would be instantaneous.
Outside bad. Inside... good?
That all sounds scary, so you know what, you don’t have to think about astronomy or history anymore. You can just lock yourself at home and stop worrying about the rest of the universe. Just grab a tub of ice-cream and wrap yourself in a blanket.
Is there anything scary about the human body? Well first of all, we are half bacteria. For every human cell that makes you you, there’s a bacterium cell in your body that is part of your microbiome. In weight that is about 2 kilograms (4.4 pounds) worth of bacteria, many of which are important in helping to keep us alive. Researchers have also discovered viruses inside us whose function is a complete mystery.
Apart from bacteria, we also have other incredible features. Each strand of DNA in our cells is tightly packed to fit a space of about 6 microns. If we were to stretch them out, it would be roughly 2 meters (6.6 feet) in length. And if we unfurled all the DNA from a single person, it would stretch from one side of the Solar System to the other. In keeping with that theme, an adult probably has around 160,000 kilometers (100,000 miles) worth of blood vessels in the body – enough to go around the equator four times.
If you are still standing after all these facts, it’s probably due to your extremely strong bones. There a variety of claims about how strong our bones are, but we couldn’t find a single recent source about it. At least we know our bones make the best daggers.
