Time Defined

Time, as we all know (or ought to know) is relative. This, for those of you who find all of that Einsteinian relativity stuff confusing, is fundamentally what the great man was talking about. Time, he said, is not a constant. It is relative. 

Now for most of us, here on Planet Earth - unless you happen to be putting a satellite in space or sending a probe to Mars or the other planets -  this is unnoticeable. This is because we are all on the same ball of rock hurtling through space. It is true that those who fly anywhere experience time ever so slightly differently, but not so that you would notice, unless you happen to have an atomic clock about your person instead of a wrist watch.

Yet this week scientists have been arguing and failing to come to agreement about the issue of time. For centuries time has been calculated, sensibly enough, according to how fast the Earth spins on its axis. This, annoyingly, varies and is not entirely reliable. For instance the Japanese earthquake last year had a measurable effect on the spin of the planet and shortened the day a little. Our not quite spherical planet, the solar system and the wider universe is not quite as perfect a clockwork machine as is sometimes imagined, although again you only notice if you happen to have an atomic clock or a god-like vantage point.

So now it is being seriously suggested that time should not be defined by the spinning of the planet we call home, but by atomic clocks which are so much more reliable. The practice of adding a leap second every few years to compensate for our planet's deficient time keeping should be abandoned.

But how is that sensible? After all, the reason our days are 24 hours long and our years 365 days was not plucked out of thin air - no, actually when you think about it, it was. Scratch that.

But that is the point. Our planet defines us. Our days and seasons are defined by it. Our months and tides are defined by that big ball of rock in the sky which acts as a giant stabiliser. Clocks only measure time, they should not define it. It is ridiculous to argue that a day should no longer be the amount of time our planet takes to complete a spin. That is what a day is. Who are we to argue with a whole planet? If it wants to change it's mind then so be it. It is 4.5 billion years old after all, is constantly being bombarded with tons of space debris, shaken by volcanoes and earthquakes and being pulled hither and thither by gravity. It's entitled to be a little contrary. The fact that a jumped up clock is telling us that it is varying a little from time to time ought to be a matter of curiosity and maybe a question on a quiz show, not an argument for a new definition.