Looking for the guilty sunspots

After the aurora, I went looking for the cause. It's this cluster of sunspots.

I drew them on with a pencil. The sun quickly moved position! The screenshot below came from here.

It is 3664 that caused the damage. This is a region, not one sunspot. It is the regions that get the serial numbers. A lot more to unpack here.

Evaporation by proxy

When I put my cup on the table, there was early condensation on the surface. I poured hot coffee into the metal enamel mug.

Lifting it after 10 minutes, there was still condensation underneath.

15 minutes later, the table had dried where the cup had been. The thermal energy from the coffee conducted into the metal walls of the cup and thence into the condensation. The warmer condensation wanted to evaporate but couldn't because there was no contact with the air underneath the cup. When the cup was removed, the condensation evaporated using thermal energy that actually came from the coffee above it.

No second helping of aurora

I tried again twice on Saturday night. At 2am, it was a 200nT Red Alert on the app. Nothing doing. In the morning I found this article here. I was interested in the classification of a G4 geomagnetic storm. Turns out there are several ways of measuring the strength of a geomagnetic storm but the G scale is from the US. See here for info.

Aurora at last

This was the alert. 

This is what the camera saw. To our eyes, much less colour and looking like cirrus at weird angles. Also wasn't expecting it south of the house. 

Zero Error

I have been noticing that the altitude readings on my app is always about 50m too high. The viewpoint on Brock Barrow has a spot height of 223m so the screenshot below confirms that magnitude of zero error. 

Oscilloscope app

Turns out I have a sound oscilloscope app. Here's me whistling. 4 cycles in 3ms means T=0.75ms. Frequency = 1/0.00075 = 1300 Hz which sounds about right. 

Under the M6

I got under the M6 at Carnforth. Not surprisingly the thick concrete is a decent sound insulator.