438 reputation
19
bio website
location
age
visits member for 1 year, 3 months
seen 1 hour ago

1h
comment why do not we use optical telescopes to study cosmc rays directly?
Since HESS, CTA and VERITAS collect blue light, why can not we use optical telescopes to collect blue light and study cosmic rays directly? Why do we build different kinds of telescopes?
1h
comment Why do we have so few neutrinos to study?
The cross section is so small that I doubt whether it is useful to put neutrino detectors in mines. How to know neutrinos are from a particular source, say, our sun?
15h
revised why do not we use optical telescopes to study cosmc rays directly?
edited body
15h
asked Why do we have so few neutrinos to study?
15h
asked why do not we use optical telescopes to study cosmc rays directly?
Jan
25
comment How do we know an event is a gamma-ray burst?
Thanks. Your comment and the reference paper help, but not much. The only way now we can tell an event is a grb is from its explosion? All the GRBs were captured in Gamma ray band initially?
Jan
20
comment the initial astrometry calibration for a telescope
how about larger non-amateur telescopes? They should be the same?
Jan
19
comment the initial astrometry calibration for a telescope
So the telescope should observe some real targets to calibrate, right? Then the reference can be built.
Jan
18
comment the initial astrometry calibration for a telescope
Thank you. BUT it seems you answered nothing. How to REALIZE that? The telescope itself knows that?
Jan
15
asked the initial astrometry calibration for a telescope
Jan
3
awarded  Tumbleweed
Jan
3
awarded  Curious
Jan
2
comment landing on a comet is more important than landing on an asteroid?
How to collect samples without landing on it? Philae will take sample back?
Jan
2
asked landing on a comet is more important than landing on an asteroid?
Dec
28
comment Which is the most early type star with a planet discovered by radial velocity method?
how do you select the x-axis range? I tried your way, but found the x-axis could be larger than 7000.
Dec
28
accepted Which is the most early type star with a planet discovered by radial velocity method?
Dec
27
asked How do we know an event is a gamma-ray burst?
Dec
13
comment where is the boundary between dark night and grey night
@rob It is the total time the moon appears in some night divides the length of that night? Or it is the area of the moon divides the full moon's area?
Dec
12
comment where is the boundary between dark night and grey night
@Rob This correlates with the moonrise and moonset time, and the lunar phase. Grey night may have a period of time which is darker than dark night. BTW, What is FLI?
Dec
10
asked where is the boundary between dark night and grey night