14,221 reputation
1642
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location Vancouver, Canada
age 44
visits member for 3 years, 1 month
seen yesterday

Mostly C++ programmer in Vancouver.
Specialising in image processing, 3d modeling, Lidar - I'm really a physicist


1d
comment Battery Capacity vs. Battery draw
Although in a real battery the voltage will drop as it empties so you probably can't use every last mAh. How far you can empty it depends on the chemistry and design
2d
comment Is “atmospheric geostationary satellite” feasible with current technology?
@jumpjack - in the stratosphere there is a predictable and stable jetstream - going around the world (in a certain direction) requires almost no energy - staying still would require a lot.
Apr
13
comment Is “atmospheric geostationary satellite” feasible with current technology?
You wouldn't have to compensate for the rotation of the earth - for the same reason you don't on the ground.
Apr
5
comment Tensile strength of a braided steel wire vs. a solid steel bar?
@LDC3 but it will be stretched, bent, pulled etc during installation - leaving unseen damage
Apr
4
comment Time to heat/cool a room
Looks good, en.wikipedia.org/wiki/Heat_conduction
Apr
4
comment Time to heat/cool a room
Yes - it's the same exponential curve as a capacitor discharging, or radioactive decay. So of course the room never totally cools. In practice it's trickier because the majority of thermal mass is in the walls, so you would have to model temperature differences within the wall thickness
Mar
28
comment How quickly does air return to a vacuum chamber?
The pressure difference is just 1 atm in the case of vacuum and depends on the height of the water in the other case
Mar
27
comment How quickly does air return to a vacuum chamber?
physics.stackexchange.com/q/12580
Mar
26
comment Cancel the Earth's magnetic field
@endolith - does this mean science finally has a way to make crabs walk forward?
Mar
4
comment Is it possible to avoid the radiation that caused the American flag turned into white on the Moon?
It would have taken from 1969 to today to get all the materials approved for use on a manned flight AND get EPA approval to ship them to the Cape.
Mar
4
comment Is it possible to avoid the radiation that caused the American flag turned into white on the Moon?
@KyleKanos = protons
Mar
1
comment Why doesn't a nuclear fuel pool become irradiated?
@Maelish - except for a small amount converted to Tritium I suppose it would. In practice the volume of water is very large compared to the number of neutrons available and the water is replaced with fresh water regularly
Mar
1
comment Why doesn't a nuclear fuel pool become irradiated?
@dmckee - sorry I had remembered that the neutron capture of D2O was almost zero, not that the capture to make D2O.
Jan
16
comment How do bicycle spokes work?
A spoke doesn't even need to be rigid, see: fiberfixspoke.com
Jan
16
comment why do we Carbonate drinks not any other gas
Not sure that fizzy ammonia soft drinks are going to catch on
Jan
14
comment What is going on with star's energy?
Space is big, really big. So most of the photons don't end up hitting anything
Jan
14
comment What needs to happen for one to ingest radioactive particles and how likely is this?
@MSalters - Yes environmental studies with such low incidents are hard to unwrap from other effects. A farming/outdoors/mountain state with lots of granite+radon might well have lower lung cancer than a rust-belt state with lots of smokers.
Jan
13
comment computer vs heater coil comparison
@portforwardpodcast - that just happened. It's no longer economic to mine bitcoins with PC+GPU because the electricity costs more than the bitcoin. But if you live in a cold country in winter and are running the heating anyway then a company will pay part of your electricity bill in return for your mining work.
Dec
29
comment Is speed of sound really constant?
For an ideal gas the expansion is perfectly adiabatic - there is no energy lost to the gas so no differential energy loss depending on frequency
Dec
29
comment Is speed of sound really constant?
Only very slightly, for an ideal gas (or a real monotonic gas) it doesn't. For a real molecular gas the absorption of energy depends on frequency and so changes the thermodynamics. It doesn't depend on amplitude except in extreme cases where you are significantly heating or compressing the gas