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location Germany
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visits member for 2 years, 9 months
seen Oct 18 '13 at 9:06

Any man more right than his neighbors constitutes a majority of one.

Henry David Thoreau


Sep
24
awarded  Autobiographer
Aug
22
comment Which color of an umbrella is more effective against sunlight?
I must admit to having a problem of comprehension. You say that black (absorbent) exterior, reflective interior works best? "... basic physics ... used for ... spacesuits ..." But spacesuits have a bright white exterior. Tell me where I'm misunderstanding you, please.
Aug
9
comment Why are there no asteroids or meteoroids with relativistic speeds?
@SebastianHenckel I interpret this FAQ (Prof. Ned Wright, UCLA) as saying that yes, very distant (highly redshifted) objects can and do move away from us at close to or even faster than c: "The time and distance used in the Hubble law are not the same as the x and t used in special relativity, and this often leads to confusion. In particular, galaxies that are far enough away from us necessarily have velocities greater than the speed of light [...]". Hence +1 from me for this Answer.
Aug
9
comment Why are there no asteroids or meteoroids with relativistic speeds?
@JerrySchirmer I'm guessing that "ISM" stands for inter-stellar medium? Which is what, wisps of hydrogen dispersed between the stars? But there wouldn't be any of that in deep space outside of galaxies, or would there?
Aug
9
comment Why are there no asteroids or meteoroids with relativistic speeds?
But the question specifically asked about "rocks from other galaxies". Well, rocks in other galaxies are moving at relativistic speeds in relation to us... the farther away from us they are, the faster their relative speeds are... but they are receding, not approaching. So we're safe.
Jul
28
comment What does “clockwise” mean, exactly?
There are people who are unable to tell their right hand from their left. (They do exist, I've met some of them.) How would you explain the right-hand rule to them?
Jul
25
reviewed Reviewed Is Mach's Principle Wrong?
Jul
21
reviewed No Action Needed Understanding bending light beam perpendicular to motion
Jul
18
reviewed No Action Needed What happens when a ball stops bouncing?
Jul
17
reviewed No Action Needed Where does electricity go from a solar panel that is not plugged in to anything?
Jul
17
suggested rejected edit on Pair annihilation - how to generaly solve these types of problems?
Jul
15
comment What evidence refutes a “pre-eternally existent cosmic egg”?
Two questions: (1) Isn't the ekpyrotic universe another type of cyclic universe? (2) According to Ben Crowell's answer, cyclical cosmologies were ruled out in the 1930s for violating the second law of thermodynamics. What has changed for a new type of cyclic universe to be entertained?
Jul
8
reviewed No Action Needed Need an intermediate resistivity part/material
Jul
8
reviewed No Action Needed If components of differing resistance are wired in parallel, how does a common voltage drop arise?
Jul
4
reviewed No Action Needed Bulk transport of an aerosol by a blast wave
Jul
4
reviewed Reviewed What is the phase difference of the oscillations of the two prongs of a tuning fork?
Jul
4
reviewed No Action Needed How do spiral arms form?
Jul
1
comment Understanding black holes
Just in case you're worried about a miniature black hole being created on earth, it's safe ;)
Jun
30
reviewed Reviewed SUSY and the Large hadron collider
Jun
30
reviewed Reviewed What's an “Action” and what does the Lagrangian equation mean exactly?