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seen Nov 24 at 15:38

Nov
24
comment moonless night and lunar phase
So when the moon is in full moon phase, it could not make moonless night? And sometimes the moon may arise late in the night,before it arises, there is no moon in the sky and the sky is dark too. However a moonless night means there is no moon during a whole night, right?
Nov
24
asked moonless night and lunar phase
Nov
19
comment is there any theory or observational evidence that our universe is electrically neutral or not?
Is there any hypothesis that some galaxy could be un-neutral? Or even larger structure could be un-nrutral?
Nov
16
comment is there any theory or observational evidence that our universe is electrically neutral or not?
You mean it could be un-neutral in galactic scale? We do not care about time-scale here. Suppose there is an isolated galaxy which loses many of its electrons and can not get the electrons back for some kind of reason.
Oct
17
awarded  Yearling
Sep
27
accepted how did James Bradley discover light aberration?
Sep
26
comment how did James Bradley discover light aberration?
If a star's radial velocity changes in a short time, its visual position will change much? Say ,a short period black hole binary.
Sep
19
awarded  Teacher
Sep
17
reviewed Approve suggested edit on Which kind of properties can we get for cosmic ray particles hitting on an optical ccd?
Sep
16
comment the metal distribution in our solar system
@Joel you are answering my question?
Sep
16
revised Which kind of properties can we get for cosmic ray particles hitting on an optical ccd?
added 127 characters in body; edited title
Sep
16
revised Which kind of properties can we get for cosmic ray particles hitting on an optical ccd?
added 94 characters in body; edited title
Sep
16
asked Which kind of properties can we get for cosmic ray particles hitting on an optical ccd?
Sep
12
comment the metal distribution in our solar system
could you please give a reference about the first question?
Sep
12
comment the metal distribution in our solar system
@dim23 The metals that are forming in the sun come from nuclear fusion? nuclear fusion of the sun? not necessarily. And what is the origin of the metals in, say, our earth?
Sep
12
asked the metal distribution in our solar system
Sep
10
comment what is the metal distribution in our universe
I revised my post in order to make it clear. My question for one kind of metal element, what is its distribution? Different metals should have different positions.
Sep
10
revised what is the metal distribution in our universe
added 53 characters in body
Sep
9
asked what is the metal distribution in our universe
Sep
9
comment The RA and Dec of lunar poles
It is empty here. en.wikipedia.org/wiki/Poles_of_astronomical_bodies