8,647 reputation
1730
bio website en.wikipedia.org/wiki/…
location United States
age 71
visits member for 3 years, 10 months
seen 2 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.


Apr
2
answered Water excitation with sine waves
Apr
2
revised How does an aeroplane maintain balance during maneuvers?
added 105 characters in body
Apr
2
answered How does an aeroplane maintain balance during maneuvers?
Apr
1
comment Spinning liquid to create a centrifuge effect
@Greasehauler: I think you have good ideas, and the only thing I might contribute is what I tell my kids and what I always told my programming students: Do small experiments. That way you can try things, and the failures will be educational and not very expensive.
Apr
1
answered Spinning liquid to create a centrifuge effect
Mar
28
comment What's the acceleration of pendulum when velocity is zero
$a=v^2/r$ is the radial acceleration, not the tangential acceleration.
Mar
27
comment Why a day is divided by 12/24 hours? Why the number 12?
How did you make that gif? It's cool.
Mar
27
comment How long can you survive 1 million degrees?
That's kinda what I was wondering about. Here you have individual nuclei peppering your skin at enormous velocities. Wouldn't they easily penetrate and do damage at depth?
Mar
27
comment Intuition behind Work
Yes. You multiply the force times the distance. The usual definition of work is "force times distance". Lift a 1-lb weight 1 foot off the floor, and you have done 1 ft-lb of work. Lift 100 lb 10 feet - 1000 ft-lb. Twice as much weight, twice as much work. Twice as much height, twice as much work.
Mar
23
comment Can anyone explain what a superleak is?
Amazing! Thanks for the video.
Mar
21
comment What mechanisms exist for generating lift on a static object?
If by propeller the OP means any sort of airfoil to which power is applied, it remains attached to the vehicle, and its lift vector can be directed upwards.
Mar
20
comment What mechanisms exist for generating lift on a static object?
+ It could be argued that this a propeller, but anyway I like it!
Mar
20
comment Surviving Free Fall with the Help of Mr. Bernoulli
@John: You're right, but it's not so much about gaining speed as about reducing the angle of attack.
Mar
19
comment Speed of the Moon
Your profile says you're a postdoc in physics, so this question seems a bit strange.
Mar
18
comment Explanation for different boiling points of water on different altitudes
+ It works the other way too. Underwater, at a depth of 1km, the water can get up to around 300C without boiling, as shown in this article.
Mar
16
comment effect of internal forces to a glider's descent
Yeah, you're basically right, I think, but don't think of the glider as making sudden changes in descent angle. Rather think of it as experiencing temporary changes in vertical acceleration, giving it short smooth curves down or up, such that the center of mass (man & glider) follows a straight line.
Mar
13
revised Why does an airplane need to climb during a takeoff even if it is in emergency situation?
edited body
Mar
13
revised Why does an airplane need to climb during a takeoff even if it is in emergency situation?
added 91 characters in body
Mar
13
revised Why does an airplane need to climb during a takeoff even if it is in emergency situation?
added 51 characters in body
Mar
13
answered Why does an airplane need to climb during a takeoff even if it is in emergency situation?