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bio website dotancohen.com
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age 37
visits member for 3 years, 3 months
seen 10 hours ago

2d
comment Why aren't there spherical galaxies?
@Ruslan: The OOrt cloud is such an example.
Nov
21
awarded  Popular Question
Nov
20
comment If your hair was on fire and you entered a vacuum, could you outlast the fire?
+1 for the information regarding the biological damage, which is missing in many of the other excellent answers.
Nov
5
awarded  Notable Question
Nov
5
awarded  Notable Question
Nov
3
awarded  Nice Question
Nov
3
awarded  Self-Learner
Nov
2
comment What are Stephen Hawking's main contributions to research-level physics?
You mention that you do not have the time to read 190 research papers. There is your answer. Hawking wrote or contributed to 190 research papers. That is quite the accomplishment.
Oct
14
comment How did Kelvin make this fascinating calculation?
This is such a beautiful answer, I wish that we could star answers as opposed to questions.
Oct
1
comment How empty of fuel are spacecraft booster rockets typically?
@David: Replace "half kilo" with "small but not infinitesimal" and "ipod" with "dirt, pollen, personal items, lice, urine still in the bladder, bird poop on the craft exterior, and other things that are not easily accounted for mass directly".
Sep
22
awarded  Popular Question
Sep
10
comment Should I abandon my thought experiment about time?
Note that watching a natural clock (the orbits of the moons of Jupiter) approach and recede (as the Earth and Jupiter got closer and further away) was one of the hints that led to the developments that led to the understanding of the speed of light, and also of the dimensions of the solar system.
Aug
10
awarded  Yearling
Jul
25
awarded  Excavator
Jul
25
revised Why does a wobbly metal sheet make the sound of thunder?
Removed redundant appeal to opinion.
Jul
25
suggested suggested edit on Why does a wobbly metal sheet make the sound of thunder?
Jul
25
accepted Calculate loudness of sound: why am I getting contradictory answers?
Jul
25
comment Calculate loudness of sound: why am I getting contradictory answers?
I see now where my confusion was. Thank you for showing the maths explained, and especially for the comment which explains why the perceived value to my ears is so much lower that what the maths make us expect.
Jul
25
comment Calculate loudness of sound: why am I getting contradictory answers?
Thank you. You certain understand how to phrase the ideas into terms that are easier to digest, and to address the points of confusion.
Jul
25
comment Calculate loudness of sound: why am I getting contradictory answers?
That wikibook is terrific, thank you!