Politics, Economics and other Stuff

“When brute force fails, you’re not using enough.”

Supposed engineering saying.  I'd not heard it before.   I like it. 

National Air and Space Museum

I ended up at the National Air and Space Museum since  a) parking on the Mall is hard, b) I didn't want to walk far in the rain once I found a place to park, c) as usual I got out of the house around 3 pm, leaving little time for a 2nd museum. 

The kids saw this museum with my wife a few weeks ago.  The main feedback, as I remember it, was 'boring'.  I see what they mean.  Also not aesthetically pleasing, dark and cramped.  The Chantilly installation is much better.  

Mostly it served as a reminder to me that I need to obtain a better understanding of the economic and technological constraints on aircraft engines.  Below the 1917/18 BMW IIIa engine, seemingly the best aircraft engine -- 200 hp with low vibration, a 'high altitude carburetor' that adjusted fuel mixture depending on pressure, and good ability to handle being turned about -- to come out of WWI.  I'd not recognized that BMW started off as a aircraft engine company, though now that I think about it I have some vague memories that I've heard this before.  Overall, a surprising amount of attention to German aircraft and engineering.  Does this reflect US aerospace industry recruitment? 

Very dark due to the rainy weather and with crappy lighting. Probably should have used flash, but I tend not to in crowds. 

Disk Breaks

I've developed a fondness for my car's breaks.  Astounding breaks work as well as they do considering the forces and the amount of energy dissipation involved. 

Why is a good autofocus system so hard to make?

The NYT reviews the Olympus EP-1 along lines that I've seen before by other reviewers:

[T]he EP-1, which will be available next month, is supposed to be the hybrid the whole world has been waiting for: the guts of a single-lens reflex camera in the body of a pocket cam.

An S.L.R., of course, is one of those big, black, bulky cameras that take magazine-quality photos. Professionals tolerate the weight and size because they have to.

Amateurs generally choose smaller, cuter cameras — but they make profound sacrifices in the process. The photos rarely look as good as S.L.R. photos, especially in low light. Far too many pictures come out blurry, because the sensor inside is so tiny. And shutter lag — the delay after you press the shutter button — is enough to drive you into therapy.  ....

[T]he final straw: the E-P1 is slow to focus. Horribly slow — sometimes two seconds. Its shutter lag is so bad, photos of athletes, passing cars and magical cute-kid shots are almost out of the question. Olympus explains that the E-P1 doesn’t have a dedicated autofocus chip, as an S.L.R. does, so it uses the same “contrast-detection” scheme as point-and-shoot cameras. Heartbreaking.

I don't have a good understanding of why good autofocus systems seem so difficult to make.   They seem to work on point-and-shoot cameras, but mostly since the demands on them aren't large since these images aren't that sharp to start with.  Canon cameras have had a whole slew of AF problems in the last few years and my 40D isn't that great for moving objects.  But you'd not even try shooting something that is moving with a point-and-shoot and expect even 50:50 AF reliability. 

A better AF system is one of the things a more expensive SLR should get you.  Indeed, it is my impression that once you get to full frame digital SLRs the competency of the AF system is the biggest difference between cameras at different price points. 

Update #1: partly the issue seems to be that getting a good AF system requires putting resources into it.  A good AF is just expensive and cutting costs results in lower performance. There is less scope for newer and cheaper and just as good or better technology. 

Why did manned powered flight take so long to get off the ground?

From today's NYT:

Philippe Frutier/European Pressphoto Agency

Edmond Salis crossed the English Channel in the Bleriot XI on Saturday in a re-enactment of Louis Bleriot’s 1909 flight.

So why did powered flight take so long to get off the ground?  Why 1909 for something of this capability and not 1880?  I assume it has to do with weight to power issues of internal combustion engines, but again, what progress was made that moved things along from 1880 to 1909?  I assume it is some combination of materials technology and casting, but it would be good to know more. 

Update #1: the Wright brothers 1903 engine was 200 lbs with 12 horsepower, and it appears that it was a light engine that made the Wright brothers succeed first, with rapid improvement from there.  Not clear though why this sort of engine was hard to build before 1903. 

'The internet consumes 1 to 2 percent of the world’s electricity'

Kevin Drum writes:

According to Jonathan Koomey, a scientist at Lawrence Berkeley National Laboratory, the internet consumes 1 to 2 percent of the world’s electricity.

True?  And what are the definitional issues here?  Koomey's web size is here, but I've not looked through it much yet, except to notice that most of his papers aren't posted.. 

Why do permanent Lift Bridges get built?

A lift bridge we drove over this weekend.  My wife wants to know why permanent lift bridges get built.  Wiki's take is:

The vertical lift offers several benefits over other movable bridges such as the bascule and swing span bridge. Generally speaking they cost less to build for longer moveable spans.^[1] The counterweights in a vertical lift are only required to be equal to the weight of the deck, whereas bascule bridge counterweights must weigh several times more than the span being lifted. As a result, heavier materials can be used in the deck, and so this type of bridge is especially suited for heavy railroad use.