Precision ink work

It's not easy constructing a perfect heptadecagon (regular 17-sided polygon) with ink.

Mathematician David Eisenbud famously showed this on Numberphile when his 17-gon demonstration went awry in amusing fashion (although the math lesson was still interesting and valid).

Professor Eisenbud's mishap spurred our audience to submit their own 17-gon attempts, some of which you can see at this link.

But no-one can top this submission from Brazilian physicist and Numberphile viewer Andre Reis Guimaraes.

Glad he didn't get Professor Eisenbud to handle the ink work!!!

Andre further explained: "I've always admired mathematics and all the amazing results you can take out of it just from some axioms, if I wasn't a physicist, I'd be a mathematician for sure.

"The tattoo was a 22nd birthday present. I was between the heptadecagon and the Mandelbrot set, but i just fell in live with the beauty of the lines.

"I've been a numberphile/sixty symbols/computerphile/objectivity fan for years now, and I really admire your work, as I admire the work of all those involved."

PS: 17-gons like this are displayed on some of the windows at the Mathematical Sciences Research Institute where Professor Einsenbud is director. The address is 17 Gauss Way.

The beginning of photography

Some amazing stuff at the Royal Society for the latest Objectivity video.

It all started with this old paper/letter from a guy called William Henry Fox Talbot in 1839.

Love the title...

Some Account of the Art of Photogenic Drawing or, the process by which natural objects may be made to delineate themselves, without the aid of the artist's pencil.

So basically, photos!

He goes on to explain...

I proposed to spread on a sheet of paper a sufficient quantity of the nitrate of silver; & then to set the paper in the sunshine, having first placed before it some object casting a well defined shadow.

And so the letter continues - an amazing glimpse into the earliest days of photography.

It is little surprise this amazing document has been valued at £800,000, or about $1.2 million.

Keith Moore (head librarian at the Royal Society) also showed us an extraordinary collection of very early photos (some are posted below).

See more about them in our video.

TEASER: One is worth more than the others. In fact it has been valued at £500,000 ($720,000).


Photos from ESO

I was just going through some old material from my trip to the European Southern Observatory in August, 2013.

Even now, I'm still posting new videos from the trip to Deep Sky Videos.

But looking at my archive of still photos, there are lots of great pictures I've hardly looked at.

Here are a handful: