Stargazing The Curse of Elon Musk: Redirect Satellites to Sun or His Backyard?

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Elon Musk's satellite deployments, particularly through Starlink, are criticized for obstructing astronomical observations, impacting both amateur and professional astronomers. While these satellites are legal due to existing regulations, many argue that they pose a significant threat to the night sky and scientific research. Suggestions for mitigating their visibility include using non-reflective materials or advanced imaging techniques, but these solutions have limitations. The discussion highlights a broader conflict between technological advancements for global internet access and the preservation of astronomical integrity. Ultimately, the rapid increase in satellite numbers raises concerns about light pollution and the future of clear night skies for scientific exploration.
  • #51
etotheipi said:
But even if you manage to fulfil this requirement, there's still the small issue of getting it off the ground :smile:
Lead is dense not massive. So it won't be hard.
 
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  • #52
Helena Wells said:
Lead is dense not massive. So it won't be hard.

but lensing is proportional to mass... it might take up less volume, but you must still do the same amount of work (and in the case of lead - an awful lot!) to bring it away from Earth! I dare say there's a reason that no one has ever tried to build a rocket out of lead...
 
  • #53
etotheipi said:
but lensing is proportional to mass... it might take up less volume, but you must still do essentially the same amount of work to bring it away from Earth! I dare say there's a reason that no one has ever tried to build a rocket out of lead...
Lensing is not just proportial to mass it is proportional to the object's density as well.
If that was the case then gravitational lensing of a neutron star could be the same with the gravitational lensing of the sun.

But yes a rocket made of lead will be more massive and we would need extra energy to lift it up.
 
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  • #54
Helena Wells said:
Lensing is not just proportial to mass it is proportional to the object's density as well.

Well, mass is proportional to density, at constant volume, though Wikipedia states the dependency of the deflection angle ##\theta## explicitly with mass, as ##\theta = \frac{4GM}{rc^2}## if ##r## is the distance from the mass to the light.

But this is besides the point...
 
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  • #55
Helena Wells said:
Lead has a density 1k times less than a neutron star so the effects are not neglible.
As I say, you need to run the numbers.

The angle of deflection for light passing a distance ##r## from an object of mass ##M## is ##\theta=\frac{4GM}{rc^2}##. The Hubble space telescope has a mass of around 11,000kg and an angular resolution of 1/20 arcsecond. Using Hubble's mass as a guide to what we can put into orbit and its angular resolution as a guide to the deflection we can detect, you would need all of that mass inside a radius of around 10-26m. Note that the Schwarzschild radius associated with 11,000kg is approximately three orders of magnitude greater than this.

A lump of lead isn't even close to producing detectable deflection of light.
 
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  • #56
Helena Wells said:
Lead has a density 1k times less than a neutron star so the effects are not neglible.
Wait, what? Did you confuse 1k (1000) with 10trillion (10000000000000)?
 
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  • #57
No I am pretty sure it is 1k.
 
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  • #58
Helena Wells said:
No I am pretty sure it is 1k.
Please cite your sources for this claim.

Edit: While I'm waiting, nuclear diameters are of order 10-14m and atomic diameters of order 10-10m. Neutronium will, therefore, be around (104)3 times denser than ordinary matter.
 
  • #59
Ibix said:
Please cite your sources for this claim.

Edit: While I'm waiting, nuclear diameters are of order 10-14m and atomic diameters of order 10-10. Neutronium will, therefore, be around (104)3 times denser than ordinary matter.
Ah yes it says white dwarfs not lead! Oups.
 
  • #60
Ibix said:
Please cite your sources for this claim.

Edit: While I'm waiting, nuclear diameters are of order 10-14m and atomic diameters of order 10-10m. Neutronium will, therefore, be around (104)3 times denser than ordinary matter.
Well blame Leonard for this.Always blame Leonard.
 
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