# I Time dilation in components of an object

1. Jul 24, 2017

### brainierthaneinstein

Apologies if this has answered before

Imagine a cannon ball that's been heated up to a very high temperature, say 1000C so it's still solid.

The atoms inside it will be moving, but the ball itself is stationary. Does this mean the atoms in the ball will age slower than the ball itself due to special relativity?

FWIW I think that's exactly what does happen - though effects will be small

2. Jul 24, 2017

### Ibix

It's certainly true that clocks attached to the individual atoms would lag slightly behind a clock at rest with respect to the center of mass of the ball. Note that thermal vibrations have a spectrum of speeds, so there would be a range of ages (edit: although the range would be very very small).

Whether that means "the atoms age slower than the ball" boils down to semantics. I'd regard it as like my Dad's hammer, that's had a new head and two new handles but is still the same old hammer he bought sixty years ago. Or so he claims. "The hammer" isn't really well-defined if we're thinking of it this way. Similarly "the age of the ball" isn't well-defined if we're thinking of its component parts as having a range of ages.

Last edited: Jul 24, 2017
3. Jul 24, 2017

### Staff: Mentor

I agree with @Ibix's very thorough and clear response

Last edited: Jul 24, 2017