Saturday, February 01, 2003

Frontier justice

I found myself watching "America's Most Wanted" tonight, which must be what reminded me of this.

The killing happened almost 22 years ago, but still no one has ever been convicted. No one has even been tried. How could they? - there were no witnesses. That's funny - it happened in broad daylight in the middle of a small town where everybody knows everybody.

The same district attorney is still there, and the case is open. I say let it stay that way.

Bush administration

C. G. Hill has some opinions.

Wellstone campaign aides weren't covered by worker's comp insurance

From the Strib, via Powerline.

Hindrocket calls it right: "This illustrates once again the principle that liberals love humanity in general, but don't necessarily care much about the particular humans who actually depend on them."

The Columbia

When I tried to get online this AM about 11 AM I couldn't get through. I figured something was up, so I turned on the tube. Wow.

At this point it looks like tile failure on the left wing was involved, but that's incredibly speculative this early into the investigation.

Although until now NASA hadn't lost anyone on the way back, that doesn't mean reentry isn't extremely hazardous in a number of ways. Even under design conditions, the shuttle strikes the atmosphere and reaching speeds of Mach 18 or so according to the NASA speaker I just heard (Mach 18 is 18 times the local speed of sound). Under such conditions the temperatures at the leading edges of the wings reaches temperatures high enough to cause structural integrity and other heat-related problems.

To address this, the shuttle is covered with special tiles on critical surfaces. The ceramic tiles not only protect the wing surface from the high temperatures, but they also help to carry away the heat by the process of sublimation as described a few posts ago here. I don't happen to know how many of the tiles can be lost before problems arise.

That's all for now. For more on this I'll be keeping an eye on Rand Simberg and Jay Manifold. And of course Glenn Reynolds is posting up a storm.

Oh yeah, a little editorial. IMO we need to change our entire attitude to the space program and either fish or cut bait. Making NASA subject to fickle funding turns their focus away from engineering toward promotion, and IMO it's clear that there's a lot of practical engineering that remains to be mastered.

A triumph of industrial design

Here, thanks to Jerry Lawson.

Weapons of Mass Destruction Handbook

It was probably around 1967 and I was in grade school when we got this neato paperback book in the mail. It was for civil defense - all about what to do in case of nuclear attacks or national disasters. I read it and reread it, and was probably the only kid who carried it back and forth to school every day. (Yeah, I was weird).

Now Grognard leads us to this Weapons of Mass Destruction Handbook.

Later he gets it wrong here, but his commenters set him right.

Disparate impact?

I've been meaning to post something on this for a while, and now it's on NRO.

Another way to generate hydrogen?

Paul Georgia contributed this to NRO today about the problems with hydrogen energy supplies. The root of it is that hydrogen is simply a conduit of energy - you have to make it from something else, and the energy you deliver in the form of hydrogen will always be less than what you put into making the hydrogen. But.....

What if you had a source of energy that was essentially free?

Yeah, right. And just what would that be? Check out this link and see.

There is a phenomenon called radiolytic electrolysis, in which radiation causes water to separate into hydrogen and oxygen. We have lots of "free" radiation from radwaste. Hmm...could this generate hydrogen economically?

Oh sure, if it is practical at all it will cost some money to implement. But we have to deal with radwaste anyway, which puts a floor on our costs in any case. Maybe for a few bucks more we can design radwaste facilities to generate hydrogen as a byproduct.

Just asking...

Tuesday, January 28, 2003

The birth of a bad policy

TV personality Jane Galt points us to this interesting item on the history of rent control in NYC.

A bouquet of Kimjongilias to...

...Gary Farber for leading us to this about a visit to North Korea.

But it will take a lot more than that to redeem the New York Review of Books.

Not for the fainthearted

This article discusses an interesting event that occurred at an abortion clinic. In it, there is a link to a picture that you might think twice about clicking - it's nasty.

And 100% legal.

Too bad the little fella hadn't had time to murder anyone, or maybe his life would have been spared. At least if he had been executed legally it wouldn't have been so...well, if you want to look, then go to the article and follow the link.

Meanwhile we have this woman who was severely wounded in an abortion clinic bombing. I'd like to ask her if she'd want to trade places.

Stolen from Rodger Schultz.

Steam tables

Anybody can blog about interesting stuff. But if you want a challenge, find something as geeky as steam tables. No, I don't mean those things in cafeterias that keep food warm. I'm talking about those little books full of numbers with the big folding Mollier chart in the back that have served generations of mechanical and other engineers. Nowadays I suppose they're going the way of slide rules and trig tables.

OK, what is a steam table? It is a listing of the properties of saturated and superheated steam, typically including entropy, enthalpy, and specific volume under various pressure and temperature conditions. Is that better?

You might think you know a little about steam, but it has many surprises. For one, there comes a point at a certain temperature and pressure (called the critical point) beyond which you can no longer tell steam from liquid water. You can have steam at temperatures well below 212°F and you can suppress it at temperatures far higher. And if you think of steam as just water vapor, you can even have steam without having liquid water first. And we engineers take advantage of all of these facts.

So why don't we see this stuff everyday? Because we live in a narrow range of atmospheric pressures, and a fairly narrow range of temperatures. Outside that range water shows us some new tricks. For instance, the pressure is elevated inside an about-to-freeze soft drink container. If you open it then, you might see some of it instantly turn to ice as the pressure is lowered. Or if you wonder where all that steam came from when you lift the lid of a pot, that's because in doing so you've just slightly reduced the pressure at the surface of the water of the pan - the steam wasn't in that state until you lifted the lid.

What if the pressure is higher? Then steam cannot form until the temperature gets higher - the steam table will tell you that temperature (the saturation temperature). This is significant because steam and water hold different quantities of energy per unit mass (the enthalpy) and behave differently in transferring their heat. So pressure and temperature states are carefully monitored in places like pressurized water nuclear reactors (where there must be no steam), inlets to steam turbines (where there must be no liquid), and pressure cookers (which cook faster, but will blow up and scald you if you don't respect their strength limits).

Now what if you lower the pressure below atmospheric? Then the steam shows up at a lower temperature. Those of you from high mountains know what this does to your cooking - the food dries out quicker even from that small change in atmospheric pressure. Having steam at lower pressures can help in sterilizing substances which might be damaged by higher temperatures.

What if you really lower the pressure? Then you can see sublimation, in which water passes directly from the solid state to a vapor. This is nothing new if you've seen dry ice, but about any pure substance will do this under the right conditions. And now you know what is done to "freeze-dry" foods. (Actually ice can turn to vapor at higher pressures, which is why your food can get "freezer burn").

Steam tables apply to water specifically, but other substances have had their properties cataloged extensively. Chief among these are refrigerants such as ammonia or Freons.

The steam tables are a bit of an idealization in that they apply to pure water. This doesn't happen very often. But they are close enough for many applications.

This PDF has some graphics and a deeper discussion of the properties of a pure substance right out of a thermodynamics book. This page defines some terms.

The female is deadlier than the male

And if you want a demonstration, just look and see what happened to Janeane Garofalo in the deft hands of Susanna Cornett.

Monday, January 27, 2003

Greenpeace blockade

John Cole strikes again with this post about the definitive watermelons. I guess they couldn't find any baby seals to kill that day.

History of Palestine

From Dawson.

Treason the title of Ann Coulter's forthcoming book. It's due out in June, but you can preorder it today from Amazon.


NWA starts its 2nd year today.