30
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How to describe the Sun's location to an alien from our Galaxy?
This has already been done. The pioneer 10 and 11 probes have a description of the solar system's location and Earth engraved for aliens to understand (or so one hopes). The physical parameters of our ...
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13
votes
Accepted
How to describe the Sun's location to an alien from our Galaxy?
If the travel was instantaneous (or say, less than a million years) it should be relatively easy to relocate the Sun from triangulation using well-known objects visible from anywhere in the Galaxy. If ...
- 141k
13
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Did the Sun's light always peak in the green wavelengths?
Nice question! Sun's spectral peak wavelength is currently 483 nm which falls under the category of green.
Sun's wavelength changing
In it's early days, the Sun was a lot cooler than it is today. So ...
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12
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Did the Sun's light always peak in the green wavelengths?
No, but that's not why plants reflect green light
The Sun, as well as the light of nearly all stars in the universe, had their peak wavelengths shift at some point during their life.
In the case of ...
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9
votes
How do people of the opposite side see the Moon and the Sun?
At the time depicted, it is close to a astronomical new moon, and night-time in Tehran. So at that time you can't see the sun nor the moon in Tehran
For people on the other side of the world (i.e. ...
- 113k
7
votes
Does the Sun have different unique orbits around barycenters?
There's only one barycenter for the solar system, which includes the impact from every planet, asteroid, comet, and space probe in the solar system. The path the sun takes around that barycenter is ...
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7
votes
Did the Sun's light always peak in the green wavelengths?
One more reference for why plants are green is Quieting a noisy antenna reproduces photosynthetic light harvesting spectra (2020). They compute the optimal absorption frequencies for a noise-...
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6
votes
How to describe the Sun's location to an alien from our Galaxy?
Since you're talking about aliens in our galaxy, I think the question comes down to whether we would expect the aliens to have a map of our shared galaxy which is sufficiently similar to our map that ...
- 211
6
votes
Is Venus in our sun's habitable zone?
What are the inner and outer edges of the Sun's circumstellar habitable zone or Goldilocks zone?
Here is a link to a list of about a dozen estimates made in the last 60 years, some using complex ...
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4
votes
How do people of the opposite side see the Moon and the Sun?
If the sky map is accurate, it will by definition look like the map (otherwise the map isn't accurate). Your position on earth changes very little about the positions of celestial bodies relative to ...
- 2,009
4
votes
Accepted
Calculating Position of Sun in GPS Frame Relative to 0°00'00.0"N 0°00'00.0"E: Determining Vernal Equinox Offset
@MikeG's comment pointed me in exactly the right direction, that of subsolar points. The Wikipedia page listed equations that came from a paper by NASA scientists. Following their equation as exactly ...
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3
votes
Accepted
Is Venus in our sun's habitable zone?
Venus, currently is not in the habitable/Goldilocks zone. However once it had deep oceans of water, millions of years ago. based on computer modellings of the climate of the ancient Venus by ...
- 1,071
2
votes
Sun or moon, finding the date and time of crossing a specific longitude
In skyfield, to find the times when something happens, you build a function that takes a Time object, outputs an integer value, ...
- 4,697
2
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Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?
If you calculate the total thermal energy of the Sun now - i.e. the sum of the thermal (kinetic energy) of its constituent particles - then it could be used to supply it's current luminosity for 40 ...
- 141k
2
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Does most of the Sun's energy and light come from its black-body temperature, due to its massive size alone? Constant crashing of particles?
A collapsing cloud of gas will generate heat from the release of gravitational potential energy, and it's core temperature will continue to rise. Indeed this is the mechanism that Kelvin and Helmholz ...
- 113k
1
vote
How to describe the Sun's location to an alien from our Galaxy?
Some very interesting answers have already been given, but a specific sentence in your proposition makes me want to try a different approach.
If your consider this segment :
alien astronomers managed ...
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How to describe the Sun's location to an alien from our Galaxy?
The simplest is to treat the galaxy as a plane and use polar coordinates. The center can Sagittarius A* (which is a massive black hole at the center). For angle, you can exploit the asymmetric, ...
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1
vote
Sun or moon, finding the date and time of crossing a specific longitude
You had the right idea with solcross and mooncross from swisseph.
The functions ...
- 18k
Only top scored, non community-wiki answers of a minimum length are eligible