Physics is Hard – or you don’t know what you think you know.

I got pinged on three interesting Physics Today articles this week.

1)   Focus: Electrons Not the Cause of Charged Grains
2)   Synopsis: Unexpected Impact from Medium-Sized Solar Flare
3)   Synopsis: Asymmetric Reconnections

There are actually interesting connections between these three papers, which only shows how weird my brain works.

1) We don’t actually know why rubbing a balloon on your head makes it charge up. SERIOUSLY. I’d assumed, as most people did, that it was something to do with electrons being pushed around… somehow. Ok, I gave it some serious thought some years ago when I was working lightning and found the theory lacking, but never had a good reason to push back. Raindrops do gather electricity, there are some good experiments to generate a charge.

The Kelvin Water dropper will generate a spark gap  – Wikipedia
 Drawing of a typical setup for the Kelvin Water Dropper

But water itself responds to positive and negative charge.



Seriously, the real effect in a thunderstorm isn’t a bunch of electrons jumping from raindrop to raindrop, but large electric fields generated by alignment of water molecules. So, in general, when talking about climate and 100 year models – people didn’t even have a good model for lightning.

2) Since we’re on the subject of Global Warming. The Human-Caused folks haven’t really dealt with how much influence the sun’s cycles have on the atmosphere. Major increases in ionization from even a relatively small event. I was expecting – around the auroral oval – that we’d see higher levels of heating and ionizing, but this paper seems to indicate strong charging as far south as England (I’d like better numbers here) as well as a significant influence in cloud formation. (At 20 km?) Well, I’ll take their word for it until I see their data.


Source – Solarham.com – gallery of images

3) What it the connection between the two papers? Electron Dynamics

The real problem with electrons is that they interact with everything, so they’re a buggar to study. One long-standing problem is assuming that they are tiny. Electrons are as large as their interaction width, which (according the the scientist at TRIUMF) he’s gotten to a mile wide in a superconductor.

This lets them do all kind of “spooky action at a distance” things, when we assume they can’t be in two places at once. They also generate magnetic fields, which influences group actions. Looking at electrons in space, we can start to see how they interact with magnetic fields, how groups of them interact with each other, etc. Seems easy enough, but it turns out we had it wrong all the time.

SO: In conclusion, Physics is hard. We learn a lot each year, but the hardest part is un-learning what we’re sure we knew last year.

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