Physics Stop

Wild weather in Waikato

Marcus Wilson Jan 28, 2010

Well, those of you living in the central North Island will probably have some idea already of what I'm going to say, but, for those of you who don't, I'll start by saying that the weather here has been rather predictable this week.  We've had three tropical-style days in a row, with a fourth shaping up the same way already.It … Read More

Say goodbye to the drill…

Marcus Wilson Jan 27, 2010

Here's a nice piece of applied physics research that will excite a significant minority of the population - specifically those who dread going to the dentist. Personally, I have never had any issues with drills (needles are a different story), but I know lots of people who do.The proposed method uses cold plasmas to kill off bacteria-infected dentin that would … Read More

Heads I win, tails you lose

Marcus Wilson Jan 25, 2010

The comment on my previous entry raises a few  issues with the way we feel heat.  (NB for those who normally read this blog on , you'll need to go onto physicsstop to see the comment - ) How hot we feel has more to do than just what the temperature is.  Anyone who has stood … Read More

Can you feel the cold?

Marcus Wilson Jan 21, 2010

Writing the last piece about fridges has reminded me about a comment I heard from a fellow student while I was an undergraduate. I can't remember the exact circumstances, but it quite possibly had something to do with objects in liquid nitrogen.  Anyway, the comment was something along the lines of 'The temperature's so low you can feel the cold radiating … Read More


BBQ Physics

Marcus Wilson Jan 19, 2010

Here's another little bit of physics seen in everyday stuff.  When disconnecting the gas cylinder to our camp stove while on holiday, I got a bit of a shock at how cold it was.  It shouldn't have shocked me - that's how it should be. When gas is made to expand it cools down. And in the gas cylinder, compressed gas is … Read More

Useful origami (and wine bottles)

Marcus Wilson Jan 18, 2010

Here's something silly and not-quite-entirely-useless for a Monday morning.Think of a deformable material (something solid but something you can squeeze, stretch, dent, etc). Maybe a bean bag, lump of plasticine, football etc. It might or might not return to its original position after you let go of it, but that doesn't matter. Think what happens if you squeeze it.  It … Read More

Dark Matter and statistics

Marcus Wilson Jan 14, 2010

While I was on holiday, news broke (e.g. see the piece in The Guardian) about the possible detection of WIMPs.  Weakly Interacting Massive Particles are what many physicists think makes up 'dark matter'.  (What is dark matter? - basically, if you analyse the way galaxies move, you discover that the amount of matter you can 'see' with conventional techniques, … Read More

Large, heavy objects

Marcus Wilson Jan 13, 2010

Our cat got the shock of his life a couple of days ago when the washing machine got up and chased him out of the room. It's not often that inanimate objects start walking on their own accord. Poor cat is probably so traumatized he'd never set foot in the laundry again except for the fact that's where his food … Read More

Ice and the freezer

Marcus Wilson Jan 11, 2010

Last Saturday I got around to doing one of those long overdue jobs in the house - defrosting and clearing out the freezer. There are numerous reasons why this was a good idea - it's not just about getting rid of the food that has been there rather too long, but also about making sure it works properly. There was probably about … Read More