Seven Quick Takes (v30): Ramblings and Musings

--1--

Must all miracles appear as signs and wonders? The supernatural special effects are cool and all, but how does it affect us to see the sun dance in the sky or a holy woman float in her ecstasy? Sure, these things can inspire conversions, but they can also be rationalized away by a convinced or committed unbeliever. Of much greater impact is the seemingly natural miracle, the sickness which knocks a man from his high horse or the war-wound which causes him to reconsider his life.

--2--

I wanted to share a drink recipe. Today's saint is St Toribio Alfonso de Mogrovejo, a Spanish saint who (along with St Rose of Lima) was the first of the saints of the New world, serving as a bishop in Peru. Therefore, it is fitting that today's drink is made from a New World booze: rum. I say rum, you say punch, and then i hit you. I say rum, and then you say "Roman Coke!" and I smile and get you a glass. Ah, but this will not literally be rum-and-coke, but rum and root beer. I'm not familiar enough with the Peruvian rums to recommend one; I used Captain Morgan's Private Stock (spiced rum), and Henry Weinhard's root beer: one shot of rum, one (12 oz) bottle of root beer, mix lightly (but not to a froth!), and enjoy. I find that root beer matches spiced rums better than coke--cream soda also works well.

--3--

This picture has been making the rounds:

I think I'll stick to khakis pants (or, heck, even jeans which fit me) and a bow-tie, thank you.

--4--

I'm currently reading through 'The Quest for the Holy Grail," written by an anonymous Frenchman of the thirteenth century. It's a rather fun story and filled with adventures and allegories; on the other hand, there are frequent breaks in the story in which the allegories are explained to the characters by wise men and hermits and anchorites. I've also been enjoying some of the prayers which the characters pray. An excerpt from one of Sir Perceval's prayers:

"Lord, be Thou my shepherd, my defender and my guide, that I may be counted among Thy sheep. And should it happen, gracious Lord, that I were the hundredth sheep, the silly one and weak, that strayed away in folly into the wilderness, do Thou have pity on me, Lord, and do not leave me in the wilderness, but bring me back to Thy fold, which is Holy Church and holy faith, there where all good sheep are, and upright men and faithful Christians all, so that the enemy, who wants nothing of me but the substance, which is the soul, may not find me unguarded."

It's also nice to read a story in which the saint figure--Sir Gallahad--is the paragon of both virtue and chivalry, a true and bold knight and a virtuous, indeed saintly, man.

--5--

One of the pitfalls to doing research in high-intensity laser science is that it's often difficult to explain my experimental parameters and constraints to the engineers who manufacture the parts I need (let alone to anyone else). Case in point: I need a very thin lens made from magnesium fluoride, which happens to have a low group velocity dispersion (GVD)*. This is relevant to my experiment, in-as-much as a short duration pulse will stretch out in time, and a larger GVD will mean more pulse stretching (which is basically bad).

On the left is the refractive index vs wavelength; 0.4 microns (the smallest wavelengths) are ~blue-violet, 0.6 microns are ~ red, 0.8 is near infra-red. The speed of light traveling through a medium is v ~c/n, where c ~2.997E8 m/s^2 is the speed of light in a vacuum, and n is the refractive index shown above. The right graph shows the effects of GVD on my pulse by showing how much a bandwidth-limited 30 fs pulse stretches as it travels through a piece of magnesium fluoride, thanks to the redder (longer wavelength) parts outrunning the bluer (shorter wavelength) parts of the pulse.

However, what is more relevant is the nonlinear self-focusing, the nonlinear refractive index, and the B-Integral, which are of crucial importance to my experiment (which is, after all, done at high-intensity). Unfortunately, most people (and especially, most optical-materials engineers) don't really encounter this kind of problem very frequently, and hence assume that I only care about the GVD. They therefore become very confused when I explain that yes, I do want a really thin lens (6mm thickness on-center, for a 3" diameter lens), but that I also need a good surface quality (since this can also cause changes in the mode shape/size/focal location/fine structure). They also tend not to have any alternative suggestions (e.g. suggestions for some other material with a smaller n2 value), nor do the companies in question tend to have such materials available from which to make lenses in the first place. Ah, the travails of science.

*GVD: think of this as saying that the speed of light traveling through the glass depends on the wavelength or frequency of the light. Thus, for example, blue light will travel more slowly than red light.

--6--

Professor Mike Adams had a nice little zinger quote: "If young people knew what 'a trillion' meant then 'no worries' wouldn't be their favorite saying." Yes, the federal debt--like personal debt, in particular consumer debt--is a moral problem and not merely an economic one. The economic problem is the easy one to solve: don't spend more than you make. The moral problem is a bit harder.

--7--

Speaking of moral problems, it's twelve o'clock and the tyrannical HHS contraception/sterilization/abortifacent mandate still hasn't been rescinded.

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Seven Quick Takes Friday is hosted by Mrs Jennifer Fulwiler at her Conversion Diary blog.