Not long ago, Anthony pointed me to this terrific panorama photo of a concert for clones:
A bit of digging reveals that it was created in Suntory Hall, Tokyo in 2006 by Martin Liebscher, a German artist who seems to have made it his specialty to make panoramas full of clones of himself.
It reminded me of a very simple clone photo of myself I once made. I had read this tutorial on PetaPixel and wanted to try it out myself. It is actually quite simple and quick to do — at least for 2 copies. I am not sure that Martin Liebscher made the photo above in an afternoon…
In my recent, very long post on the optics of solar halos, I briefly mentioned the phenomenon of total internal reflection: If a ray of light propagating in a material with a high index of refraction, such as water or ice, encounters an interface with a material of a lower index, like air, it will be completely reflected if it enters with a large angle of incidence (close to parallel with the interface). This explained why the sunlight would not be deflected by ice crystals to form the halo for certain incidence angles.
Total internal reflection is also responsible for the working of optical fibres. This is demonstrated clearly and convincingly in this video by Bill Hammack, aka. Engineer Guy that I found via Make. In the first part of the video he very elegantly shows how a laser beam is reflected multiple times inside a narrow stream of transparent liquid. I recommend you to watch the whole video which covers a lot of science and engineering related to fibre optic cables. But stay focused! There is an impressive amount of information packed into those 5:36 minutes.
Engineer Guy has made many other videos covering different technologies. I will certainly try to watch them all.
I usually write blog posts and my private plain text notes in Markdown using the PHP Markdown Extra flavour which adds syntax for very useful features like tables and footnotes. It is a pretty clean markup language that makes WordPress writing a bit more comfortable than with either Visual or HTML, the two standard post editors.
Try to zoom in or out and see how beautifully the formula scales. It is even (to some extent) copy-pastable.