7,445 reputation
1628
bio website en.wikipedia.org/wiki/…
location United States
age 70
visits member for 3 years, 1 month
seen 46 mins 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.


Sep
4
revised What will happen if a plane trys to take off whilst on a treadmill?
deleted 195 characters in body
Sep
3
comment Which angle causes an object to land quickest?
@Hayeder: And another way to put it is height. The one that rises the least will hit the ground first.
Sep
1
comment Water, can it break through temperature?
@Harry: No, because there's no free lunch. The energy you get from the H and O combining was transferred from the hot object into the H and O when the water hit the the object in the first place, thus cooling it off. Think of every problem in terms of energy balance.
Sep
1
comment Water, can it break through temperature?
@Harry: You have to provide some kind of ignition, but right, it gets a lot warmer :) In fact, that powers rocket engines.
Aug
30
comment Water, can it break through temperature?
+ Yes. It's important to point out, as you did, that the zirconium stole away the oxygen.
Aug
30
revised Water, can it break through temperature?
added 6 characters in body
Aug
30
answered Water, can it break through temperature?
Aug
30
comment Why is there this asymmetry between the two foci of an orbital ellipse?
Well, I don't know, but the same thing happens if you take a planar cut, at an angle, through a cone. The curve you get is an ellipse, and the center of the cone is one focus of the ellipse.
Aug
29
comment What is the possibility of a railgun assisted orbital launch?
@Phill: That exponential formula only applies for rockets that have to hoist the fuel they will use further up.
Aug
29
revised What is the possibility of a railgun assisted orbital launch?
grammar
Aug
29
comment What is the possibility of a railgun assisted orbital launch?
I have to wonder, what is the effect of air friction? It's being shot in the thickest air at what, Mach 25? Seems you need to add a nose cone and some extra speed, just to have enough speed left when you get out of lower atmosphere.
Aug
27
comment How much thrust would be needed to turn a hobbyist weather balloon into a deep space probe?
+ Yeah. It's a classic mistake. Getting into space takes a small fraction of the energy of getting into orbit, let alone escaping.
Aug
23
revised What will happen if a plane trys to take off whilst on a treadmill?
deleted 2 characters in body; added 294 characters in body
Aug
23
answered What will happen if a plane trys to take off whilst on a treadmill?
Aug
20
comment How fast would someone have to run to run over water?
Well, if you could run this fast...
Aug
20
awarded  Civic Duty
Aug
18
comment How to compute the speed necessary for an airplane to fly?
@Rody: OK, you win :) I'm just a pilot.
Aug
18
comment How to compute the speed necessary for an airplane to fly?
@Rody: The relationship between the Bernoulli effect and downwash is very simple: you can't have one without the other. Regarding inverted flight, it's simply a matter of the angle of attack (which directs the downwash), and that affects the point at which the air approaches the rounded leading edge, which affects the difference in distance traveled by the air over one side of the wing versus the other. This has been thoroughly discussed.
Aug
17
revised How does a car turn without any skidding?
added 165 characters in body
Aug
17
comment How does a car turn without any skidding?
@RodyOldenhuis: Then it can turn in a circle about the center of the rear wheel. Then what I said earlier about there being some skidding at the rear wheel due to the width of the contact patch applies.