All in camera, single exposure lighting painting drawn with one bulb torch, one CREE LED and a 77mm red filter. And a decent pair of wellingtons.
Please do check it out in Lightbox - looks more compelling on black.
It's taken in the middle of the River Colne in Mill End. Light painting in the river is actually far more relaxing than you might imagine. The main worry when light painting in desolate locations at night is the fear that some misguided nutter with a hand axe will ambush you, drawn like a moth to your flailing lamps. This spot is a hundred yards along from any accessible bank, so you are screened by vegetation on all sides, out of sight, with a sizeable moat all around. Defensible.
For light painting, or any nocturnal work, I would highly recommend it. When you don't have a river, I'd suggest an invisible dog. Initially I went with "Siegfried", but have renamed him "Totem" which you can shout with a decent military bark. Simply shout for your imaginary dog now and again, perhaps interspersed with allusions to his ferocity. For example;
"Totem - get back here this minute. If you've killed another fox/moose/commando you'll be sleeping in the kennel tonight, you hyper-aggressive, 200 lb mongrel you." You get the idea.
As regards the title, I'm trying to correct an issue identified by Gregory House MD; "Physics joke[s], don't hear enough of those."