8 facts about time that mess with our heads

Did you know your head experiences time faster than your feet?

Ever feel like a particular year went by faster than previous ones in your life? That things seem to be going quicker the older you get? Sometimes it’s in your head and sometimes time really is weird. Time is relative. We don’t just mean that in the sense that time flies when you’re having fun. It really is relative, just ask Einstein.

Here are our top 8 facts about time that make our heads spin. Some of these facts are about the nature of time itself while others are simply related to how we imagine time and the misconceptions most of us share.

8. T. rex lived closer in time to us than to Stegosaurus

Never trust movies. How many times have we seen a stegosaur swing its tail at a hungry T rex? We often have a poor comprehension of when things happened in the prehistoric past since our own experiences relate to the tiny length of a human life.
Modern humans have been kicking around for a few hundred thousand years, which is the blink of an eye as far as time on Earth goes. The time between now and T. rex going extinct seems vast at about 67 million years, but Stegosaurus lived about 155 million years ago. We’re quick to point out that humans and dinosaurs (at least the non-avian variety) never coexisted, but if you ever see a picture with a T. rex and Stegosaurus together then that’s even worse.
Image © giphy.com

7. Cleopatra lived closer in time to the moon landing than the building of the great pyramids

It isn’t only timespans of millions of years that we tend to get wrong. Even more recent events in human history can be longer than many of us truly appreciate. When I was young I had a children’s encyclopedia that had a picture of Cleopatra overseeing the creation of the Great Pyramids. This is so wrong that a picture of her watching the Apollo 11 moon landing would have been an improvement. She lives a good 2500 years after the construction of the Great Pyramid of Giza.
Image © giphy.com

6. Many people witnessed both the Wright Brothers’ first flight and the Apollo 11 moon landing

This fact is as much about the rate of technological advancement as it is our perception of time. The Wright Brothers were flying the first airplanes in 1903. Just 66 years years later Neil Armstrong and Buzz Aldrin were walking on another world. Many people were alive during both events and old enough in 1903 to appreciate both of them. Imagine in your lifetime seeing the creation of powered flight and then the first mission taking humans to the moon. It’s sad that 45 years have passed and we still don’t have moon bases.
Image © giphy.com

5. We never really experience the present

The present is now. Right? That’s all well and good but neuroscientists and physicists don’t think it’s that simple for us. For neuroscientists, it’s clear that it takes our brain time to actually process anything our senses detect. We’re always reacting to something that happened milliseconds ago. Physicists take this even further and argue that there isn’t really a present anyway, as it’s all relative.
Image © giphy.com

4. The length of days is always changing

The solar system has been around for 4.6 billion years and in that time the planets have changed a lot. Not only is Earth now polluted and crawling with beasties, its orbit and even spin have changed drastically over the billions of years. The drag of the moon is actually slowing down the spin of our planet, affecting the length of days. Today we have 365 days in a year with each day lasting almost 24 hours. When dinosaurs were around there were 370 days in a year and each day lasted about 23 hours. Thanks to the moon we have an extra hour in bed.
Image © giphy.com

3. The higher you are, the faster time is for you

The higher you are, the faster time passes for you. No, we don’t mean high on drugs, though it may have the same effect. Because of our evolution, we imagine time and space as two different things but really they exist together as spacetime. Gravity warps spacetime, so time moves slower the closer you are to the Earth. If two people were born at the same time but one lived on a mountain while the other lived at sea level, their ages would differ by 15 microseconds every year. You might expect time to be faster for astronauts on the International Space Station (ISS) since they experience even less gravity, but time is actually slower for them because of the next fact…

2. The faster you move, the slower time passes

Astronauts come back younger than we expect them to be because they travel so fast. Spacecraft and the ISS travel at high speeds; the average speed of the ISS is about 17,000 mph. The closer you get to the speed of light, the closer you get to time stopping (from your perspective). If two people were born at the same time and one stayed still while the other hurtled through space, they would soon be different ages. Weird.
Image © giphy.com

1. It could be possible to influence the past

The double-slit experiment shows the weirdness of quantum mechanics and how we perceive time. Something that’s almost as weird as time is light, which is both a wave and a particle. The bizarre thing about the double-slit experiment is that light passes through a slit either as a particle or a wave depending on whether you observe it happen or not. This is the Observer’s Effect.

There’s a variation of the double-split experiment called the delayed choice quantum eraser and it’s even weirder. The actual observation takes place after the light has passed through the double-slit but before it hits the wall and reveals whether it’s a wave or a particle. This means that when the observation happens, after the light has passed through the slit, it determines what state the light was in back when it passed through the slit. If we built this experiment at an interstellar scale, we could make decisions now that would affect events millions of years in the past!

Image © giphy.com

Time facts not weird enough for you? Try our top 7 maths facts that blow our minds or our top 5 mind-breaking physics facts.

Main image © iStock/123ducu