9 Science Facts To Make You Sound Clever At Parties
5. "Your Head Is Technically Older Than Your Feet"
This one is easily slipped in if people start talking about their age (somewhere around "How old are you then?" and "Oh god, I feel so old").
Initially, this sounds like some kind of metaphor for wisdom or something, but it's not, it's actually a principle of relativity.
There's this thing called Gravitational Time Dilation, it's a part of Einstein's Theory of Relativity and it means that the speed at which time passes is relative to the distance it is from a gravitating mass.
Basically, the strong the gravity, the slower the time.
The reason behind this phenomenon is to do with the relationship between the fact that gravity bends spacetime and that the speed of light is a universal constant.
The closer you are to a massive object, the more spacetime is bent, and the further light has to travel between two fixed points. But in order for the speed of light to remain constant, it is time that has to run slower in order to allow the light to "catch up".
As nuts as this sounds, it has actually been observed in the real world. For example, the clocks on the satellites orbiting the earth actually run faster than the clocks on the ground and have to actually be programmed to compensate for this. Oh, and matters are complicated even further by the fact that the speed of an object also alters the speed of time.
Because the laws of physics apply everywhere in the universe, this is also happening to your head and your feet, but to a much less noticeable extent. Depending on your height, you head will be some billionths of a second older than your feet by your 80th birthday.
If they push you any further on this, you can simply respond with "Well, it's all relative, isn't it?" and nod sagely.