560 reputation
410
bio website david.carybros.com
location
age
visits member for 4 years, 8 months
seen yesterday

Jun
2
comment How to recover an unfocussed image
@docscience: Yes, it's often easier to analyze blurring in the Fourier domain, and "The Mathematical Uncertainty Principle" of the Fourier transform is very similar to Heisenberg's uncertainty principle. Consider re-asking that question as a stand-alone top-level question, linking to this question.
Mar
22
awarded  Notable Question
Nov
22
awarded  Popular Question
Nov
20
comment Is it possible to create a parachute large enough to stop all velocity?
+1 for mentioning "cloud suck".
Sep
20
answered Why does Energy-Momentum have a special case?
Sep
13
answered How to determine your position underground?
Aug
29
revised How do you add temperatures?
fix glaring typo; mention "average"
Aug
29
suggested approved edit on How do you add temperatures?
Jul
11
comment Is it possible to overload a lightning rod?
Ah, right. However, several 2-story buildings in my area have a wire from the lightning rods on the roof to a ground rod pounded into the ground. I hear "Lightning Cable must have at least 59,450 circular mils of conductivity." (which is approximately 1/4" diameter). A 0.022"x2" strap is about 56,000 circular mils -- less beefy, right? P. 5 of "How Does a Lightning Rod Work" mentions "The US lightning code suggest approximately 1/4 in. diameter copper wire".
Jul
11
comment Is it possible to overload a lightning rod?
Why do your calculations based on the thick, rigid ground rod hammered into the ground, and not on the (relatively) flexible 1/4 inch copper wire or 3/8 inch aluminum wire connecting the lightning rod to the ground?
Jun
3
awarded  Promoter
Jun
1
asked Is it more efficient to stack two Peltier modules or to set them side by side?
Mar
31
comment How is gravity consistent when you split an object into multiple pieces?
If you already know some calculus, there's a good proof at hyperphysics: "Gravity Force of a Spherical Shell" and more-or-less the same proof at Wikipedia: "shell theorem".
Mar
1
comment Toroidal Planets
@AlanSE: Yes, the plots indicate local gravitational+centrifugal acceleration of a co-rotating object. There is a local minimum outside the outer equator, which is geosynchronous orbit.
Mar
1
comment Toroidal Planets
@AlanSE: Huh? Are you even reading the same article I'm reading? The io9 article I read says "The cross-section is neither circular nor elliptic but rather egg-shaped, with a slightly sharper inside curvature than on the outside. ... having a low gravity equator and high gravity poles does not mean stuff will roll or drift towards the poles: ... the surface is an equipotential surface, so gravity (plus the centrifugal correction) is always perpendicular to it."
Jan
18
revised Intuitively, how can the work done on an object be equal to zero?
edit, as requested
Jan
18
suggested approved edit on Intuitively, how can the work done on an object be equal to zero?
Jul
21
comment Can a moon have another large body as a satellite, and are there any examples of such?
This reminds me of the rings of Rhea.
Jul
21
comment Is it possible to orbit the sun next to Earth?
@dmckee: I agree with most of what you say, but I would have said people have "very little practical experience" with solar sails, given the success of IKAROS, MESSENGER, etc.
Jul
17
awarded  Yearling