New York Times on the Web Forums Science

Missile Defense

Russian military leaders have expressed concern about US plans for a national missile defense system. Will defense technology be limited by possibilities for a strategic imbalance? Is this just SDI all over again?

gisterme - 03:10pm Jul 6, 2001 EST (#6695 of 6698)

rshowalter wrote ( rshowalter 7/6/01 1:46pm ): "...Now let me give an example from Chaison. Space telescope can just resolve the difference between a car with one headlight, or two, from a distance of 2000 miles

(if that car happened to be in space - so that smearing by the atmosphere didn't make the seeing worse.)

Robert, I'd have to agree with that conclusion if an automobile headlight (or two) was the only target signature that was availabe to locate, track and aim. But consider that an automobile headlight (H4 Halogen) is typically a 100 W object that's about 6" in diameter. The light results from the exertion of about 0.13 horsepower. The heat plume from a 57,000 lb thrust rocket is an object hundreds of feet long resulting from the exertion of about a half-million horsepower. While it's true that those aren't real comparisons of luminosity at particular wavelenghts it gives an idea of relative energy available to a distant detector. The rocket plume is like a giant infrared arrowhead pointing directly at the rocket saying "here I am...shoot me!". It's about 3 orders of magnitude larger than the headlight and perhaps 4 orders of magnitude brighter. Why wouldn't that be orders of magnitude easier to detect, track and aim at than the one or two headlights in the example that you've given?

gisterme - 03:26pm Jul 6, 2001 EST (#6696 of 6698)

Here's an interesting link...has some good history about BMD development up to 1995 (Lt. Gen. Malcom R. O'Neill):

http://www.spacer.com/news/bmdo-99e.html

"...Mr. Chairman, it is my privilege to appear before this hearing with the Subcommittee on Research and Development today to testify on the accomplishments of the Ballistic Missile Defense program. I am delighted that this committee has taken the time to hold multiple hearings on the Ballistic Missile Defense program. However, I am particularly pleased that today we will address the specific accomplishments the Department of Defense and industry have achieved in making ballistic missile defenses a reality..."

Much more...

rshowalter - 03:30pm Jul 6, 2001 EST (#6697 of 6698)
Robert Showalter showalte@macc.wisc.edu

Let me try to respond neatly. Give me an hour.

(I haven't shaved or showered yet today, and I'd like to -- and I'd like to give the answer in a way that will be easy to see.)

How I wish people were a little more literate about how math and practical stuff connects --

Wouldn't take much --- just to see that math answers

" how much? questions, which practically arise for all sorts of reasons, and language alone can't handle alone

(you need words, pictures, and math, together.)

If people were taught that early, maybe by the 6th grade, and taught that the guts of math, no matter how far you go (that is, for the stuff people use) comes from

arithmetic ---

algebra (the arithmetic that uses symbols for numbers) ----

geometry . . . .

and from these, analytical geometry and calculus --

With these four fields focusing each other in interaction . .

If people just knew a little bit about how these things grow up together -- and connect to measurable, usable things -- and if people just memorized and learned the 20 or so symbols mathematicians used --- some of these technical issues wouldn't be so hard for people to understand -- and a lot of mistakes could be sorted out.

Back in an hour, cleaner, with an answer for your really important question.

(1 following message)

New York Times on the Web Forums Science Missile Defense