Physics part II

The bottle actually looks rather like me

Not really fishing this, but another example of my inability to focus on the physical world. I had a pleasant cycle along the cliff road from Brighton to Saltdean the other morning and since it was hot, thought I'd pack a bottle with cold water from the fridge. All we had was the fizzy variety so I decided to treat myself to that. After 20 minutes a sodden patch had appeared at the bottom the rucksack and was making its way through my top and down into my trousers. Of course, the bubbles in the water had caused the bottle to expand.

Where's the fishing you say? This is the water bottle I usually take with me on summer trips. I save the kettle for later in the year. So there.