If It's April It Must Be Time to Visit Professor MacKay and His Map of the World

We've dropped in on the good professor a few times, usually in Spring.
From the website of David J. C. MacKay:

David MacKay's Map of the World

(click to enlarge)

Power consumption per person versus population density, in 2005. Point size is proportional to land area (except for areas less than 38 000 km² (e.g. Belgium), which are shown by a fixed smallest point size to ensure visibility). Both axes are logarithmic. The straight lines with slope -1 are contours of equal power consumption per unit area. Seventy-eight per cent of the world's population live in countries that have a power consumption per unit area greater than 0.1 W/m². (Average powers per unit area are sometimes measured in other units, for example kWh per year per square metre; for the reader who prefers those units, the following equivalence may be useful: 1 W = 8.766 kWh per year.)

If you want to know more about what's going on with the map, do visit his map page.
MacKay used to hang his hat at Cambridge's Cavendish Laboratory.
I don't really know what they do at the lab, I think it's where the Nobel Prize in Physics is made.

Mackay left the lab in 2013 to be the University's first Regius Professor of Engineering.
He has a bunch of letters after his name.
Previously:
April, 2007
Sustainable Energy-without the hot air
April 2013
Here is THE Problem Facing Alternative Energy

We also visited the Professor in 2012. By then I had shortened the introduction:

His Wikipedia entry is basically "David J.C. MacKay, see: heavyweight."*

Here's another April 2013 visit:
"16 Lectures on Information Theory and all that"

Here's his Cambridge website.
When people want to talk energy with me I usually ask if they have read his book.