Equation Conundrum in Floods

We had a walk along the Macclesfield Canal the other day and I saw a narrowboat with this on the side.

While I can find the right hand part of the equation in some references, I can't find the whole of it and believe it is some form of physicists' in-joke. Can anyone perhaps throw some light on the joke?

Yesterday the Peak District got a bit flooded. to say the least. Here's the reservoir at Whaley Bridge on Tuesday, before the deluge, and after. Locals said they'd never seen anything like it in their lifetimes.

Roads were flooded and blocked, houses were flooded - bit of a disaster all round and I doubt if many have house insurance.

There was a section of road where a bridge had overflowed and we had to wait while some locals kindly cleared the debris. A bunch of young builders in a truck behind us started beeping their horn as we patiently waited. I wish I'd had the time to warn them that this was inadvisable. As it transpired, they were staying at our hotel and followed us for about a mile into the hotel car park - Hay beamed when she saw them follow us. the poor driver didn't know what hit him. He eventually apologised to her. Naturally I had to look burly and handy and muttered something about impatience, not that Hay needed any assistance from me at all as she tongue-lashed the driver, who was clearly embarrassed in front of his mates.

There are some new houses being built just behind the reservoir at Whaley Bridge - I would not advise anyone to buy them...

We also went to Bakewell, where I saw these padlocks festooning a footbridge.

If only I had a couple of paperclips I could have had hours of fun...

In the 70s and 80s there was a TV sitcom with Thora Hird and Christopher Beeny called In Loving Memory. It was set in a family funeral parlour in Yorkshire called Jeremiah Unsworth's. Well, in Whaley Bridge I spotted this sign...