Posts Tagged ‘Astronomy’

Black Iron Apostasy

July 10, 2013

For years I’ve heard tales of how good cast iron pans are, how they heat evenly, how they are non-stick if properly seasoned, how they need TLC to stay that way. I’m beginning to think that’s pretty much equal parts nostalgia, and hype. The trouble is, once something becomes accepted folk knowledge, it stays that way. It’s like the New in New York. Once something is “New”, it’s New forever.

Let me give you another example, from amateur astronomy. For years, decades really, all the amateur astronomy books said that you shouldn’t point your telescope through a closed window, because the imperfections in the glass would destroy the seeing. That’s true, if your house was built before 1960 and so used sheet glass, but the 1950’s saw the development of the Pilkington float glass technique, where very smooth glass was made by floating it on molten tin. It took almost half a century for the “don’t look through a window” advice to finally change. Yes, there are times you don’t want an additional refractive layer in front of your scope, but there’s also the dead of winter and the height of mosquito season, times when you don’t mind a little refraction.*

Cast iron is the sheet glass of the cooking world. Yes, a well seasoned pan is more non-stick than the pre-Apollo pans your grandmother used, but no, it’s not as non-stick as teflon or some of the more modern coatings. And, no, it doesn’t distribute heat evenly.

I see two uses for cast iron pans. First, for searing. If I have a chunk of meat that I want to cook quickly at high heat, or I have a sous-vide that needs a bit of brown, then I pull out the cast iron frypan. I put it in the oven to get it afterburner hot (there’s nothing on it to melt), then pull it out (wearing heavy gloves, using potholders), and drop the meat in. I have to be sure the kitchen fan is set to mega-suck, or all the smoke detectors will go off at once. Cast iron does hold heat very well, so that pan is still sear-your-flesh hot when I turn the meat. When I’m done with the searing, I turn off the oven and stick the pan back in. Leaving it in a hot oven won’t help cleanup, but if it’s in there I won’t forget and try to grab a still-hot handle barehanded ten minutes later (remember, the non-stick part is only relative). When everything has cooled down, I take it out and clean it.

The second use is outdoors, over a fire. As I said, it won’t melt. It won’t burn. It won’t even scorch. I’ve been using mine to heat beans and such on the BBQ when grilling meat, since that lets the food pick up some of the flavorful carcinogens from the meat smoke and drippings. I am still experimenting with that approach. If I set it between the charcoal holders and put the meat directly over it (indirect heat), I get juice, but I have no control — I’d have to pull the meat and lift the grill to stir it. If I set it up on the grill I can control the heat, and stir and stuff, but I’m dependent on second-hand smoke for flavoring. That’s grilling at home. Camping is something else. I haven’t been camping for decades — not since that time with the Girl Guides in Thetford Chase — but if I did, I’d take along the cast iron pan for campfire cookery.

As for care, I soak it overnight, scrape the big chunks off, hit the rest with a scouring pad, and pop it into the dishwasher. Yes, it destroys the seasoning and takes away the non-stickiness, but I’m not going to be cooking omelets in it. When I take it out, I hit it with a shot of Pam and wipe it off. That keeps the rust away.

*Yes, I know about warm air currents and distortion, but that’s primarily a problem if it’s an open window, or if you have a radiator directly under it.


Patrick Moore 1923-2012

December 9, 2012

Patrick Moore was, in his day, the most famous amateur astronomer in England, if not the world. We lived in England in the early 70’s, the heyday for the US space program. Whenever something interesting was happening, Moore was the man the BBC would turn to to describe it all to us. He died yesterday, aged 89.

Broken World

October 19, 2012

A recent paper in Science describes how the Earth became a hellish desert for over five million years as a result of the Permian Extinction. The trigger is still unclear, and suggested causes range from asteroid impacts to runaway greenhouse effect due to volcanic eruptions. In the tropics, sea temperatures were 40C (104F), and land temperatures were over 50C (122F).

Most of the discussion of the paper appears to be the implications for the current era of global warming. What I find interesting is the fact that it puts severe constraints on the development of life-as-we-know-it.

The tropics were barren hells for five million years. That’s an eternity in evolutionary time. There was life at the poles (or we wouldn’t be here) but it was not able to modify itself enough to recolonize the tropics. What tropical life there was, was shrubs and ferns, and there were no tropical fish, not even guppies.

This puts an upper limit on the allowed temperatures for life on earth-like planets, and gives us a better criterion for setting the inner limit of the ‘Goldilocks zone’ around a star. Yes, it’s possible that life-as-we-don’t-know-it might develop, based on asbestos or something, or that, given half a billion years, rather than just five million, life on earth could adapt, but it helps us better understand just what our limits are.

Happy Eliza Doolittle Day!

May 20, 2012

As I said in more detail in my last post, we have arranged a performance by Solar Eclipse, on tour for one day only, Asia, Pacific, and the US. However, the situation looks bad for the NENW performance (scheduled for 5:30PM), with extensive cloud cover threatened. And it turned out to be true.

At 4PM it wasn’t looking good

The cloud cover remained until nightfall, and the satellite image wasn’t much help.

At 6:30 all we had was a slight darkening of the southern half of the frame

Moon Viewing

August 12, 2011

…is the literal translation of Tsukimi (月見). I originally thought it was also the basis for one of the character names in Kanon — Tsukimiya Ayu — but her name (月宮) translates as ‘Moon Palace‘. Moon viewing is the autumnal equvalent of the springtime Hanami ceremony, the viewing of cherry blossoms by moonlight, only there are no special floral arrangements, other than pampas grass (and no, pumpkins don’t count). The full moon is celebrated on the 15th of August (actually, this year it is full on the 13th), people wear Yakutas, and special moon-shaped foods, like dango are served. There are many varieties of dango.

Super Harvest Moon

September 22, 2010

Not the game, the real thing. Full moon at Autumnal Equinox. Here is a writeup. It’s tonight, Wednesday, so get out there and look. Note that we are only a couple nights past the closest approach of Jupiter to Earth in about 40 years, so that bright star next to the moon is pretty much as big as it gets.

In the modern recreation of our supposed Celtic past (and who doesn’t yearn to be Irish?) this is the festival called Mabon, and for the Japanese, it is しゅうぶんのひ. In the Anglo-Saxon lunar calendar, this full moon would probably signal the boundary between Wéodmónaþ (weed month) and Háligmónaþ (holy month)*.

We haven’t had a hummer at the feeder for a full week now, so I guess it’s time to bring them in.

*This is a correction, I was at the wrong month boundary.

First Quarter Moon

August 26, 2009

Tonight is a first quarter, or waxing moon. As seen from Earth, it’s a half moon, and thereby hangs a tale.

When you look at a half moon, one that looks like this:  D  , you are looking at the sunrise line, or terminator. Yes, you can see the terminator if you look at a crescent moon, or a gibbous moon, but it’s only when you are directly over the sunrise line that you see that kind of a half moon. When you look at the moon at your local sunset (about 19:00 PDT in the Summer) you are standing on the sunset line of the Earth, also called the terminator. If you think about it,  the only way this can happen is if the moon is directly behind the Earth in its orbit around the Sun. Go do a drawing. you have the moon and the Earth in line, like this:  o  O –>  with the arrow indicating the movement of the Earth in its orbit. To complete the picture, the Sun would be off the top of the page, and the bottom half of those circles would be dark.

Now, the Earth travels about 29.6km/sec in its orbit around the sun. And the moon, on average, is 382,500 from the Earth. (Bear with me here, the math is almost over).  So, the Earth covers the Earth-Moon distance in about 3.5hours.

That means that when you look at a First Quarter Moon, at sunset, you are looking at the very spot in space that the Earth was at, 3.5 hours ago. In the morning, should you be up early enough to see a Last Quarter Moon at local sunrise, you will be looking at the very spot in space where the Earth will be about the time you sit down for your pre-luncheon snack.

Go out tomorrow evening and try it.

Updated to make timeless.