All Questions
44
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The astonomer's method of color differencing as applied to proving Einsteinian relativity during a total solar eclipse
I'm looking to see if the astonomers' method of color differencing was ever applied to the stars near the Sun during a total solar eclipse, for example, to demonstrate Einsteinian relativity visually ...
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3
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2
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Is it possible, by monitoring the brightness of stars, to find a “copy of the Earth + Moon” near them?
More than a dozen Earth-like planets have been discovered around nearby stars based on observations of changes in the brightness of their sun as they pass across its disk (transit events). If an Earth-...
- 158
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Why does a total solar eclipse happen every 18 Months?
What is the math involved in calculating how often a total solar eclipse happens. Can you predict it by just looking at the period of the moon around the earth and the period of the earth around the ...
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What math predicted the eclipse of Betelgeuse?
It's amazing that scientists can predict something as small as last weeks eclipse of Betelgeuse. The general relativity aspects are quite specialized. Can someone point me to the math involved in ...
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1
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Temperature estimate from eclipsing binary
So assuming perfect edge on eclipsing binary, we can estimate the temperature ratio of the two stars because the "blocked area" is the same, and thus the amount of light "dimmed" ...
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3
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Why is it so dark during a solar eclipse?
At a total solar eclipse the sun is barely covered, like right after sunset. So why is it much darker than right after sunset (which allows us to see the corona)?
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Proof/explanation that Sun is bigger and more distant from Earth than Moon is, Middle Age technology allowed only
If I was living in the Middle Ages, how can someone prove or at least explain to me in a simple way that the Sun is bigger and more far from Earth than the Moon?
Can a parallax be used for it?
$$\text{...
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2
votes
1
answer
91
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Is a 3 body system with a permanent eclipse possible and stable?
Is it possible to have a star, planet and moon where the moon orbits the planet in the opposite direction with the same period of the planet orbiting the star? So that there would be a never-ending ...
user86478
2
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1
answer
86
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Why Earth is viewed crescent from moon when the Earth is experiencing total solar eclipse?
Suppose a person, let's say Neil, is on moon and Earth is experiencing a total solar eclipse so how should Neil perceive the Earth? This is also a question from KVPY (5/11/2017) question no. 22. as ...
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-1
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What is the logic behind the Eddington expedition that proved Einstein's general theory of relativity?
The Eddington expedition in 1919 proved Einstein's general theory of relativity.
[Eddington] argued that the deflection, or bending, of light by the Sun’s gravity could be measured... because ...
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1
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Definition of eclipsing binaries?
In the second minimum (the 3rd step) there is a smaller decrease in light intensity. For this to happen, wouldn't you need to be looking at the plane of orbit from above rather than directly along the ...
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2
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1
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What is the derivation of this formula for eclipsed flux?
From my lecture notes:
Planetary Transit Searches
If a planetary system’s orbital plane lies along our line of sight, planets will from time to time pass in front of their star, absorbing some of the ...
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19
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7
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What is a simple argument to prove that the stars in the sky are further away from the Earth than the Moon?
How do we know, without using modern equipment, that the stars are further away than the moon in the night sky? Further, is there a simple and actionable argument to prove that this is indeed the case?...
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4
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4
answers
752
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Why does the shadow of Io on Jupiter look so big?
It has been reported this week[0] that the following image by Kevin Gill is the shadow of Io crossing Jupiter.
Why is the shadow so large? My intuition is that Io is much smaller than Jupiter so ...
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3
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239
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Can we determine the date just from sky observations?
Assuming everyone "freezes" for several thousand years. Then everyone unfreezes at the same time. Could we tell how much time passed based on sky observations without fancy telescopes?
(Just started ...
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