8,607 reputation
1730
bio website en.wikipedia.org/wiki/…
location United States
age 71
visits member for 3 years, 10 months
seen 7 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.


May
3
revised Passively moving air
added 12 characters in body
May
3
comment How does a hovercraft hover, if it has low pressure underneath it?
I suppose they call it "low pressure" because it's lower than "high pressure".
May
3
revised Passively moving air
added 157 characters in body
May
3
answered Passively moving air
Apr
30
answered Is current in superconductors infinite? If they have 0 resistance then I (V/R) should be infinite?
Apr
29
comment Why is the water in a cup not inclined (opposite the cup) when the plane takes a turn?
Actually, airplanes can make a wings-level turn, just by pressing a rudder pedal, and in that case, you and your coffee do feel a sideways force. But it's slow, uncomfortable, and very inefficient, compared to just banking into the turn.
Apr
27
comment How to make a structure of which water flows out at a constant rate?
What you need is constant pressure. Check out carburetor.
Apr
27
comment How to make a structure of which water flows out at a constant rate?
The key is the float-operated valve. Carburetors have had this for a century.
Apr
23
comment Do rotating non-circular projectiles also experience Magnus lift?
Almost any method of inducing circulation produces lift by deflecting the airstream. Simple example: take a strip of paper 1/2" wide by a few inches long. Hold it the long way between your hands and drop it, with backspin. It keeps backspinning and glides quite nicely.
Apr
23
comment A moving brush on a vibrating surface
I suspect where the bristles touch the surface not completely vertical there is a ratchet action.
Apr
22
revised Can a car get better mileage driving over hills?
added 279 characters in body
Apr
22
answered Can a car get better mileage driving over hills?
Apr
22
comment Why is the water in a cup not inclined (opposite the cup) when the plane takes a turn?
Because planes don't turn the way cars do, they turn the way bicycles do.
Apr
20
comment When we are inside a plane and look outside the window why does everything (outside) appear to be at rest?
When you see movies about flying, they try to make it exciting by zipping in and out between clouds, so you get a sense of speed. In real flying, you want it to be as boring as possible. You stay far away from clouds, and everything else, if you have a choice. Clouds are bumpy, they block your vision, and other planes can be hiding in them.
Apr
18
answered In aircraft design why are light materials preferred to heavy ones?
Apr
17
answered Uncertainty and wave-trains
Apr
17
comment Why is wave a function of volts?
@user78162: Sure. You could go to an electronics store and buy a cheap voltmeter. Actually, what it measures is current through the little coil attached to the needle, but there's a resistor in series, so if you want to measure voltage, it does so. The trouble with a multi-meter is the needle is mechanical and can't move very fast. An oscilloscope trace can move faster and also show you the trace over time, that's all.
Apr
17
answered Why is wave a function of volts?
Apr
15
answered Is fuelless aviation possible?
Apr
14
comment Why do we use capacitors when batteries can very well store charges?
I see your point.