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1642
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location Vancouver, Canada
age 44
visits member for 3 years, 1 month
seen 14 secs ago

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


Dec
26
answered How does Kepler's laws and Newtons universal gravitation for two bodies come together?
Dec
24
comment Precision of spectroscopy for astronomy
@Frank - no, that's the great thing about redshift. You measure the relative speed directly. The main complexity for these high precision cases is taking into account the motion of the Earth (and your instrument) around the sun - as one group found out a few years ago.
Dec
24
comment Precision of spectroscopy for astronomy
The new echelle for VLT will do 10cm/s and hopes to do "a few" cm/s
Dec
20
comment Is it Possible to Determine Radiation Levels Using Satelites?
The atmosphere is transparent to visible light, it isn't very transparent to gamma rays (fortunately). You can only detect radioisotopes at a distance if they emit something that reaches you. Alpha and Beta radiation don't travel far enough and it would be an unlikely radioisotope that got high enough into the atmosphere for its gamma ray emissions to reach a satellite - in any significant quantities.
Dec
19
awarded  Necromancer
Dec
11
comment How close would Earth have to be for us to detect it was habitable, and then inhabited?
@Jonathan. Tricky, you are looking for a small absorption dip in the sunlight reflected from a planet when the star is 10^10 brighter
Dec
10
comment How can ambient cooling cool a system to below the ambient temperature?
@FilipHaglund - yes but you would have to do extra mechanical work - this is what your refigerator does.
Dec
9
answered Stretching a rod?
Dec
9
answered What is the transmittance function of a photo filter?
Dec
9
awarded  Informed
Dec
8
revised How can ambient cooling cool a system to below the ambient temperature?
added 245 characters in body
Dec
8
answered How can ambient cooling cool a system to below the ambient temperature?
Dec
7
comment How much lift does the average latex helium filled party balloon produce?
@b_jonas - the question is how much lift. But yes you need to subtract the envelope from the "useful" payload
Dec
6
answered How is the Earth heated by a Full Moon?
Dec
3
comment Is everything 100% efficient at heating?
There was a report (admittedly from U Alberta) which showed IIRC a tiny increase for BC and Quebec. Essentially places with almost 100% hydro electric but natural gas heating and little summer AC. They also had a small local increase in Mercury because they don't have much coal fired capacity to reduce. Across the country and most of the world though CFLs are a "good thing"
Dec
3
comment Is everything 100% efficient at heating?
Ironically in some areas with hydro-electricity but gas heating the introduction of CFLs can significantly increase emissions in winter.
Dec
3
awarded  energy
Dec
2
revised If microwave ovens and WiFi both operate on the same frequency, why doesn't WiFi cook things?
typo
Dec
2
answered Is the total energy of earth changing with time?
Nov
30
comment Do heavier objects fall faster?
@mahos - sorry I noticed that but there is no way to withdraw a dupe flag.