1,124 reputation
418
bio website dotancohen.com
location
age 36
visits member for 2 years, 8 months
seen Apr 13 at 5:47

Jul
8
comment Beads in 'perpetual motion'?
Thank you. I suppose then that there is very little friction in this system? Also, I am having a difficult time determining a method for calculating the amount of force being exerted on the floor.
Jul
8
asked Beads in 'perpetual motion'?
Jun
26
accepted Why is the Pegasus launched from a subsonic airplane?
Jun
26
comment Why is the Pegasus launched from a subsonic airplane?
Thank you, I did not realise everything else in the launcher.
Jun
26
answered Why are spacecraft made to “spin” after launch?
Jun
26
comment Why is the Pegasus launched from a subsonic airplane?
Thank you. I don't see any information even suggesting that the M-21 crash was due to to a supersonic separation.
Jun
26
comment Is space “real”, or is it some sort of accepted postulate?
Spacetime
Jun
26
comment Is space “real”, or is it some sort of accepted postulate?
I see, Peter, you mean the dimensions of space. You'll be happy to known that we can in fact measure them, and there there are more than just three of them!
Jun
26
answered Is space “real”, or is it some sort of accepted postulate?
Jun
26
asked Why is the Pegasus launched from a subsonic airplane?
Jun
6
comment Might a planet perform figure-8 orbits around two stars?
Thank you, the illustration makes it clear exactly why this system is unstable.
Apr
23
awarded  Popular Question
Apr
15
accepted Other than the motion of the Earth, what else would cause parallax?
Apr
15
comment Other than the motion of the Earth, what else would cause parallax?
Right. Thank you!
Apr
15
comment Other than the motion of the Earth, what else would cause parallax?
I see, thanks. Therefore Bradley's discovery of aberration was the final bit of needed evidence?
Apr
15
comment Other than the motion of the Earth, what else would cause parallax?
Thank you for the very informative answer. You do discuss why aberration is easier to detect than parallax, which answers another (unasked) question of mine, but the core question is not addressed: Why was Bradley trying to measure parallax if it had not been discovered yet? And if it had been discovered (or suspected), yet the Earth was supposedly stationary (because Bradley's discovery proved that it wasn't), then what would explain the parallax?
Apr
2
accepted How is celestial navigation done on a low-level?
Mar
22
comment How is celestial navigation done on a low-level?
Thank you. The Apollo podcast is very informative.
Mar
22
asked How is celestial navigation done on a low-level?
Mar
22
awarded  Popular Question