8,542 reputation
1730
bio website en.wikipedia.org/wiki/…
location United States
age 71
visits member for 3 years, 9 months
seen 3 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.


Mar
5
comment Understanding Quantum Physics
@EmilioPisanty: Thanks. Good edit. One of the best hours I've spent. I love his salt-of-the-earth presentation and Brooklyn accent.
Mar
5
comment Understanding Quantum Physics
@Kitchi: I put it above. Actually wizzup found it at youtube.com/watch?v=hUJfjRoxCbk
Mar
5
revised Understanding Quantum Physics
added 376 characters in body
Mar
1
answered Effective angle of attack of a wing
Feb
27
comment Aircraft nose-up glide
@Jodes: No. That would depend on how the wings are mounted, what the glide ratio is, and what the speed is. For the C172, the glide ratio is about 9:1, so the descent angle would be about 6 degrees down. The angle of attack would be about 10-15 degrees up, totalling about 4-9 degrees above horizontal. I'm not sure what angle the wings are mounted at. It also depends on the pilot's height and how high the seat is adjusted w.r.t. the cowling. There's no natural line indicating "true horizontal" on an airplane. It's all relative. At high speed it feels like falling out the front.
Feb
27
revised Aircraft nose-up glide
added 87 characters in body
Feb
27
answered Aircraft nose-up glide
Feb
26
answered What's the surface area of a liquid? How does evaporation increase if the surface area of a liquid is increased?
Feb
26
answered Re: recoil (bounce) of objects under varying gravitational forces
Feb
25
answered Would Oscars made of pure gold bend?
Feb
25
awarded  Notable Question
Feb
24
comment When did Voyager-1 achieve Solar System escape velocity?
@Chris: The diagram in my answer says Voyager 2 exceeded solar escape velocity in its encounter with Jupiter, and then more with Saturn. I can't find a similar diagram for Voyager 1, but it must have been similar. According to the list of escape velocities, at Earth, it takes 11.2 km/s to escape Earth, but 42.1 km/s to escape the sun. That's like 14 times as much energy. That's how much harder it would be without the slingshot effect.
Feb
24
comment Measuring acceleration of a bus using water between two sheets of glass
+ nice answer. There's a simple way to measure it. Measure the height $h$ and base $b$ of the triangle. Then the acceleration of the bus is $g$ times $h/b$ (assuming driving on a level street).
Feb
24
revised When did Voyager-1 achieve Solar System escape velocity?
deleted 3 characters in body
Feb
24
revised When did Voyager-1 achieve Solar System escape velocity?
added 101 characters in body
Feb
24
revised When did Voyager-1 achieve Solar System escape velocity?
deleted 16 characters in body
Feb
24
answered When did Voyager-1 achieve Solar System escape velocity?
Feb
22
answered Understanding Quantum Physics
Feb
21
comment Why does string not wick down?
@Adam: Also, where the string bends over the edge of the cup, I would assume the string is somewhat laterally compressed at that point, squeezing shut the voids that the capillary flow goes through.
Feb
21
comment Needed Energy For Lifting 200 kg weight
Energy is force times distance, that is, weight times height. Power is energy per unit time, so if you lift it slow, it doesn't take much power. If you lift it fast, it takes a lot of power. After you run the numbers, it's just a matter of converting units.