List of physics courses of the University of Oxford Updated +Created
Quantinuum H1 Updated +Created
rshell Updated +Created
Monitors Updated +Created
Supernova Updated +Created
Rich people who create charitable prizes are often crooked Updated +Created
A friend of mine who's a rich man - he invented some kind of simple digital switch - tells me about these people who contribute money to make prizes or give lectures: "You always look at them carefully to find out what crookery they're trying to absolve their conscience of."
But do you know what, Cirism is totally fine with taking indulgences to absolve someone from their past sins, so long as they have repented. Everyone deserves a second chance.
HP spinoff Updated +Created
World War II Updated +Created
Elastic collision Updated +Created
Helium-3 Updated +Created
Lie bracket Updated +Created
North America Updated +Created
South America Updated +Created
Schor's algorithm Updated +Created
System of linear ordinary differential equations Updated +Created
Model organism Updated +Created
Spherical cap model of the real projective plane Updated +Created
Ciro Santilli's preferred visualization of the real projective plane is a small variant of the standard "lines through origin in ".
Take a open half sphere e.g. a sphere but only the points with .
Each point in the half sphere identifies a unique line through the origin.
Then, the only lines missing are the lines in the x-y plane itself.
For those sphere points in the circle on the x-y plane, you should think of them as magic poins that are identified with the corresponding antipodal point, also on the x-y, but on the other side of the origin. So basically you you can teleport from one of those to the other side, and you are still in the same point.
Ciro likes this model because then all the magic is confined just to the part of the model, and everything else looks exactly like the sphere.
It is useful to contrast this with the sphere itself. In the sphere, all points in the circle are the same point. But this is not the case for the projective plane. You cannot instantly go to any other point on the by just moving a little bit, you have to walk around that circle.
Figure 1.
Spherical cap model of the real projective plane
. On the x-y plane, you can magically travel immediately between antipodal points such as A/A', B/B' and C/C'. Or equivalently, those pairs are the same point. Every other point outside the x-y plane is just a regular point like a normal sphere.
Rock (geology) Updated +Created
Biosensor Updated +Created

Unlisted articles are being shown, click here to show only listed articles.