Theoretical aspects of astronomy

Why it was worth sending a rover to Gale Crater on Mars – lesson from the Amalfi Coast in Italy

This photos shows erosion in action on this island – like tje central peak in the martian Gale Crater, layers of rock are visible – the lower ones must have been laid down before the higher ones allowing a rover to sample different geological ages as it climbs the central mountain of the crater.


Island showing layering in rock similar to central mointain in the martian Gale Crater:

Wormholes and multi-dimensional universes

For those of you interested in this sort of thing, here is a puzzle.

I retired fully a couple of weeks ago, and the physicists in my old department gave me a klein bottle.


It is a sort of 3-dimensional Mobius strip (

It only has one surface, and therefore has no volume (and I have a certificate to prove it!)

You can get water into the bottle.

Given it has no volume, where is the water? In another dimension? Has it gone through a worm-hole?!!

I will bring it along to the next meeting, (as long as it hasn’t disappeared into another dimension!)