## Archive for January 26th, 2009

### I’m not a Mathematician, but I Play One on TV

Calculus and “The Method”

A Prayer for Archimedes

Two of the texts hiding in the prayer book have not appeared in any other copy of Archimedes’s work, so no one but Heiberg had studied them until now. One of them, titled The Method, has special historical significance. It could be considered the earliest known work on calculus.

Archimedes wrote The Method almost two thousand years before Isaac Newton and Gottfried Wilhelm von Leibniz developed calculus in the 1700s.

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### I Get No Kick from Champagne

So tell me why should it be true?
That I get a kick out of you

gg writes up the recent paper on the Abraham-Minkowski controversy

Measuring the ‘kick’ of a photon leaving a fiber!

The difficulty lies in the fact that any discussion of the momentum of light in a medium must properly account for the total momentum of the system, which includes the momentum of the medium itself. When traveling into a medium of refractive index much greater than unity, the light is strongly interacting with the material and it becomes almost arbitrary to distinguish between the momentum of the photon and that of the matter: the two are completely intertwined. With this perspective, one would say that the designation of ‘light momentum’ and ‘medium momentum’ are completely arbitrary, merely different ways to slice ‘total momentum pie’. Differences in experimental results can be explained away as a failure to completely account for the interaction between the light and the medium.

### Wait for it …

Long Exposure Photography: 15 Stunning Examples

Something to try out. I just ordered a locking shutter-release for my digital SLR

### Action-Reaction Blows

Balloon-powered boat

Which could be a DIY project, I’m sure. You could adapt the idea to a DIY hovercraft as well.

### Free the Facts

Free the Facts A Flickr set by Dave Gray

Facts are an important element of any decision-making process. A fact asserts that something is the case. When we as a society make decisions that affect our future, facts, and conversation or argument about what they mean, is a critical part of those decisions.

But what is a fact, and how do we know that something is a fact? Is there a “keeper of the facts?”

This little thread is an exploration of facts: What they are, how they come to be, who has access to them and why. It’s especially focused on the facts that make up the sum of our scientific knowledge.

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