1,769 reputation
715
bio website markbeadles.com
location Columbus, OH
age 47
visits member for 3 years, 2 months
seen Jan 28 '13 at 17:55

Jul
20
comment Could cell-phone radiation cause cancer?
This is not responsive to the question, which is "Is there a physics model that would suggest a mechanism...that could lead to cancer".
Jun
18
comment What would make the bottom of my cocktail glass develop a fractured pattern like this?
I think you are correct - this looks like crazing
Jun
15
comment At what g is terminal velocity not terminal?
Your figure of $0.6m/s^2$ doesn't match the moons you've selected; off by a factor of 10. Pluto would be a better example.
Jun
15
comment Nature of orbit due to central force!
en.wikipedia.org/wiki/…
May
8
comment How do I relate the direction of a compass needle to the direction of a current?
@JohnRennie The problem is compounded by the fact that the Earth's North Magnetic Pole is a south pole. :P
May
7
comment Magnetic Permeability & Reluctance on old exam question
That figure for magnetic permeability of free space doesn't seem to be right.
Mar
15
comment Einstein's Gedanken Experiment that lead to the Special Theory of Relativity
@JohnRennie was already adding in the other text as you posted :)
Feb
28
comment What happens when a supersonic airplane flies through a cloud?
@AaronDigulla It's a cloud layer it is going through...I wouldn't say it's deformed as such; really the effect is sort of like ripples on a pond when you throw a pebble in.
Feb
28
comment What happens when a supersonic airplane flies through a cloud?
An Atlas V rocket certainly goes supersonic. If you go to the linked page, you can see that the shocks map to the discontinuities in the rocket surface quite nicely. Also, the shocks are not in front - it's hard to tell but the shocks form a cone behind the rocket. Again, check the linked page for a diagram.
Feb
28
comment What happens when a supersonic airplane flies through a cloud?
It's a "Prandtl-Glauert cloud" from the P-G 'singularity'.
Feb
28
comment In-flight damage to a supersonic jet
Mike is correct - if the engines can't go supersonic, you could always use gravity! But there is an ideal shape for supersonic flight (en.wikipedia.org/wiki/Sears-Haack_body) and any deviation from that shape will tend to cause shock waves. The shock waves cause rapid compression and decompression near the surfaces. This can then lead to resonance conditions like flutter or buffeting, where resonance causes vibrations to grow and grown until things fall apart.
Feb
26
comment Frequency of nomad planets passing within 30 AU of the sun
Further: since one can assume that there are many more Pluto-sized bodies than Jupiter-sized, then let's say then that the distribution is roughly logarithmic: we get on average a Pluto-sized body every 50 million years, a Moon-sized body every 150 million, a Mars-sized body every 350 million, an Earth-sized body every billion years. Doesn't sound unreasonable at all.
Feb
23
comment Experimental proof of gravitational redshift of light
Great minds, etc.
Feb
21
comment Keeping air in a well
If the planet is Earth-like in its geology, digging a hole deeper than 50km is going to be problematic since you'd be up against the mantle.
Feb
21
comment Keeping air in a well
For what it's worth: Mars's Hellas Planitia is 23km below datum and has 30km-high walls, and the atmospheric pressure at the surface at the bottom is 1155 Pa; normal atmospheric pressure is only 610 Pa. Not good enough for humans either way. :(
Feb
17
comment What is the Correlation Between Solar Wind Velocity/Density and Sunspot Count?
iopscience.iop.org/0004-637X/587/2/818/fulltext/16823.text.html
Feb
15
comment 17 Joules of Energy From a Mouse Trap
I was going to make this a joke comment but then I realized that it's an answer :)
Feb
13
comment If an anti-matter singularity and a normal matter singularity, of equal masses, collided would we (outside the event horizon) see an explosion?
This is fair enough, I will edit my answer. Thanks.
Feb
9
comment units and nature
What you are saying, @RonMaimon, is that basically all the units are like the candela. They're just there to make things convenient for human experience.
Feb
4
comment Physics of the Internet?
This user's profile indicates he is a HS student. I am willing to give him the benefit of the doubt.