7,230 reputation
1625
bio website en.wikipedia.org/wiki/…
location United States
age 70
visits member for 3 years
seen 10 hours ago

BS Mechanical Engr.
PhD CS(AI)
CS Prof (4yr)
Numerous consulting jobs.
15 yr at http://www.pharsight.com
Published book on CS & several articles
4 kids, 2 grand
Pilot(student)

P.S. The picture is a Beta-prime distribution. It shows the program speedup factors you can get if you see a problem twice in 2, 3, 4, and 5 samples.


Aug
17
comment How does a car turn without any skidding?
@mcFreid: Actually, since a tire contacts the road in a patch, not a point, the side of the patch away from C does have to travel a larger distance. So it does skid a little bit that depends on how wide the tire is.
Aug
17
comment How does a car turn without any skidding?
@mcFreid: As long as we're simplifying, idealize the wheel to be zero width (a knife edge of super-hard material). It rolls forward and backward without slipping. The path on which it rolls does not have to be perfectly straight, does it? From instant to instant, it can turn a little bit without slipping, because it contacts the road at an infinitessimal point.
Aug
17
answered How does a car turn without any skidding?
Aug
16
comment What would be an appropiate shape for a parachute?
@user1002327: It's the same as in any aircraft. For the given weight and wing area, there is a speed that's too slow, called the "stall speed", where the wing ceases flying and becomes a parachute. The speed that gives maximum time aloft is just above stall speed. You adjust the speed by trimming the weight more or less forward.
Aug
16
revised What would be an appropiate shape for a parachute?
added 109 characters in body
Aug
16
answered What would be an appropiate shape for a parachute?
Aug
15
revised Phase shift of 180 degrees on reflection from optically denser medium
edited title
Aug
15
revised Could a real-life X-Wing fly in Earth's atmosphere?
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Aug
12
comment What differs string theory from philosophy or religion?
@Ron: I should clarify that the comment regarded a time before Christianity really got going, and the religions being talked about were whatever the various tribal peoples being conquered happened to have.
Aug
12
comment What differs string theory from philosophy or religion?
If can interject a slightly humorous aside, Gibbon, in "Decline and Fall of the Roman Empire" related that adherents of religions knew they were true, philosophers knew they were false, and magistrates knew they were useful.
Aug
12
comment What is the relationship between kinetic energy and momentum?
Look here.
Aug
10
revised How much force is required to propel a bicycle?
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Aug
10
revised How much force is required to propel a bicycle?
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Aug
10
revised How much force is required to propel a bicycle?
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Aug
10
answered How much force is required to propel a bicycle?
Aug
8
revised Why is there a wave on the water surface when I put something in the water?
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Aug
8
answered Why is there a wave on the water surface when I put something in the water?
Aug
8
comment Why are radians more natural than any other angle unit?
I seem to remember when it was considered to divide the circle into 400 "degrees", to make navigation a little less error-prone. As it is, pilots have to just "know" that 7 and 25 are opposite ends of a runway, and be really really careful not to mix up 13 and 31.
Aug
8
comment Why are radians more natural than any other angle unit?
Nice...........
Aug
8
answered Is there other uses of flow-straighteners than flow-metering?