Unanswered Questions
201 questions with no upvoted or accepted answers
3
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0
answers
333
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Angular momentum in planetary disk formation
Reading about the formation of planetary disks, one of the major problems, it seems like, is the evacuation of angular momentum. Aparently planets can't form with the amount o angular momentum the ...
- 704
3
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0
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75
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How exactly can the hypothetical conformal invariance of the CMB spectrum be established by analyzing tensor modes?
In the introduction of this paper at the top of p11, it is mentioned that a hypothetical enhancement of the scale invariance of the CMB spectrum to conformal invariance could potentially be ...
- 809
2
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0
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84
views
Would we know if the universe was rotating?
I was wondering what we would observe if the universe had a small rotation. My conclusion was that galaxies on the equatorial plane of the universe would be slightly more redshifted than galaxies than ...
- 373
2
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0
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102
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What would the Big Crunch theoretically look/feel like?
In the Big Crunch theory, the expansion of the universe reverses, resulting in all matter contracting into a single point. Imagine you are alive at the time of this event. What would the sky look like?...
- 29
2
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174
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What happens at the edge of a finite and "bounded" universe?
So far, we know only about two types of universes: Infinite and finite universes (Unbounded edition).
In an infinite universe, there is no edge. Because well, an infinite space doesn't have an edge. ...
- 2,668
2
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0
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34
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Local anisotropies in the expansion of the universe and tidal forces...?
In the context of the large-scale structure of the universe, there can be local anisotropies (https://www.aanda.org/articles/aa/full_html/2021/05/aa40296-21/aa40296-21.html).
I understand from this ...
- 1,017
2
votes
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answers
70
views
How is an index of n=0 possible for the Lane-Emden equation?
I was recently showing that an index of $n=0$ for the Lane-Emden equation results in constant density throughout the star. However, in my calculations I had to use the constant $\alpha$ which can be ...
- 106
2
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60
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What could these LMC objects in this color-color diagram be?
I have performed a color-color and colour-magnitude plot of various sources detected in an LMC image (JWST NIRCAM F200W, F150W and F115W filters). I then also queried SIMBAD to collect relevant ...
- 21
2
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89
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Could entropy be reversed eventually in the far future?
In the far future there will be most likely a point where a maximal state of entropy will be reached in the universe and after the last black hole evaporates there could be no more structures and no ...
- 1,017
2
votes
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answers
42
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Colossus sigma function not reading the changes in the code
am currently using the colossus package on Python, which helps calculating functions that are relevant in Cosmology.
I am interested in calculating a Matter power spectrum, and use it as a base to ...
- 21
2
votes
0
answers
34
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Could rogue planets with cold nucleus have winds or water currents/waves due to the planet's rotation?
Are there any types of wind or waves caused and produced only and exclusively by a planet's rotation? Not influenced by the planet's rotation, but produced solely by it?
In the case of waves, are ...
- 1,017
2
votes
0
answers
61
views
Is there an equation that can give position of a satellite around a parent body as a function of time?
I’ve been looking into this lately, and most sources I have used solve this problem numerically. I was thus wondering if there is a proper equation to solve for position without numerical, especially ...
- 201
2
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0
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101
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Conversion of 1D plot in 3D plot gives different physics
I am to track the path of a particle due to Lorentz force of the planet magnetic field, assuming there is no gravitational force on it.
The equation of motion due to Lorentz force in rotating ...
- 145
2
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0
answers
255
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Abundance of an element Xi in mass fraction from its abundance by number
How can I calculate the expression of the abundance of a given element Xi in mass fraction from its abundance by number Ni/NH, where log(NH) = 12 is the abundance by number of hydrogen?
I've tried the ...
- 4,800
2
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98
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Empirical Constraints on the Time Evolution of Cosmological Redshifts
The standard model of Cosmology predicts that the redshift of a single source at fixed comoving distance varies with observation time according to
$$ \dot z = \left( 1+z - \frac{H(z)}{H_0} \right) H_0....
- 121