What is time? Physicist Albert Einstein demonstrated that time is an illusion; it is relative – it can vary for different observers depending on your speed through space.
Fascinating Insights into Astronauts’ Lives in Space
For Einstein, time is the “fourth dimension”. Space is described as a three-dimensional realm, providing astronauts with coordinates – such as length, width, and height – to represent their position. Time adds another coordinate or dimension, although it typically only flows forward.
Einstein’s Special Theory of Relativity states that time flows faster or slower depending on how quickly you are moving relative to another object. If you approach the speed of light, a person inside a spacecraft will age much more slowly than their twin who remains on Earth.
According to this theory, space astronauts would be younger by 0.005 seconds compared to people on Earth if they lived in space for 6 months. If we apply this to astronaut Scott Kelly, who recently returned after a year working on the International Space Station (ISS), he would have aged a mere… 0.01 seconds less than his twin brother, Mark Kelly.
Furthermore, according to Einstein’s General Theory of Relativity, gravity can bend time. This phenomenon is known as the gravitational time dilation effect, meaning that the closer an object is to the center of Earth, the slower time passes for it.
However, this does not mean we should hide in basements in hopes of achieving a longer lifespan, as the effects of time dilation are minimal compared to ordinary reference frames; the time differences are nearly imperceptible. Yet, there are examples that can truly baffle your mind:
- A clock attached to your foot runs slower than the watch on your wrist.
- Your head ages faster than your toes.
Of course, if we were to conduct a large-scale experimental model, the consequences of the gravitational time dilation effect would be very clear. The most notable example is that clocks on GPS satellites tend to run slower than similar devices on Earth by about 38 seconds.
