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Nov
7
comment Twin paradox in special relativity
This question has been asked many, many times before.
Nov
7
comment Twin paradox in special relativity
Possible duplicate of How is the classical twin paradox resolved?
Nov
7
reviewed Leave Closed Could we recognize our galaxy by looking at it from a different place in the universe?
Nov
7
reviewed Close Coordinate Time and Proper Time/Simultaneity
Nov
7
reviewed Leave Open Are atoms more attracted to each other when you raise or lower the the temperature?
Nov
7
reviewed Leave Open Why do physicists use a positive sign for the Fourier kernel / outward propagating waves?
Nov
7
reviewed Close Conceptual Change thinking needed
Nov
7
reviewed Close Magnetic field due to current, I don't get how you get the direction, can someone draw it for me?
Nov
7
reviewed Leave Open Trace representation of density matrix question
Nov
7
reviewed Leave Open Backwards in time?
Nov
7
reviewed Close Why can't electrostatically accelerated deuterium beams neutralized by electrons produce net energy fusion?
Nov
7
revised Mercury-in-glass thermometer
Typos
Nov
7
comment Mercury-in-glass thermometer
I musty confess that I can't see why water wouldn't work in the thermometer. The thermal expansion coefficients are similar. Obviously water has a more limited range as it's only liquid from 0°C to 100°C while mercury is liquid from -39°C to 357°C.
Nov
7
awarded  particle-physics
Nov
6
comment Why does a ruler continue to slide after toppling?
@Gert: Ha! Experiment trumps wild speculation from the theoreticians! :-)
Nov
6
answered Why does a ruler continue to slide after toppling?
Nov
6
comment Why does a ruler continue to slide after toppling?
@Gert: wrong! The base of the ruler will already have started to move away from the ridge/book as the ruler approaches horizontal. In the last stages of it's fall the COM is no longer moving in a circular arc, so you cannot use this to argue the $x$ component of the velocity is zero.
Nov
6
reviewed Looks OK Does “sum over all paths” in the path integral imply “sum over all paths” in momentum space when one Fourier-transforms?
Nov
6
reviewed Leave Open Could we recognize our galaxy by looking at it from a different place in the universe?
Nov
6
reviewed Leave Open Terminal Velocity of 100lb Hail