High School Could a Black Hole Cause a Sunrise in the West?

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SUMMARY

The discussion centers on the hypothetical scenario of a black hole passing between Earth and the Sun, potentially causing the Sun to appear to rise in the west. Participants clarify that while black holes can bend light due to gravitational lensing, the phenomenon described would not occur as suggested. The consensus is that such an event would not result in a visible sunrise in the west, as the gravitational effects would not be strong enough to alter the Sun's position in the sky. Additionally, the discussion touches on the stability of Earth's axial tilt and the influence of the Moon on this stability.

PREREQUISITES
  • Understanding of black hole physics and gravitational lensing
  • Knowledge of Earth's axial tilt and its stability factors
  • Familiarity with astronomical phenomena such as solar eclipses
  • Basic principles of light refraction in Earth's atmosphere
NEXT STEPS
  • Research the effects of gravitational lensing in astrophysics
  • Study the role of the Moon in stabilizing Earth's axial tilt
  • Explore the mechanics of solar eclipses and their visual effects
  • Investigate the historical changes in Earth's magnetic poles and their implications
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Astronomy enthusiasts, astrophysicists, and educators interested in gravitational phenomena and the dynamics of celestial bodies.

  • #31
Maybe not specifically, but the general idea is that the liquid core is not spinning consistently with the rotation of the Earth, but rather has some additional bulk movement. Exactly why and how is not really known, but given the planet is geologically active, I don't see this to be a shocking phenomena.
https://www.nasa.gov/topics/earth/features/2012-poleReversal.html
 
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  • #32
rootone said:
I think we can agree that the unpredictability of Earth's magnetic poles is weird though,
Is there any mainstream theory which it explains it?

From my astronomy 101 class I learned that much like the sun, the magnetic lines get tangled and break causing the pole swap and that we experience it at a far slower rate than the sun.
 
  • #33
Ashraf Siddiqui said:
I simply want to know probability of sunrise in the west
Get in a rocket ship and fly west at greater than the Earth's rotation rate. Eventually you'll catch up with the sun.

Edit: alternately, wait till sunset and go up a tall elevator. The sun will rise again over the western horizon.
 
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  • #34
snorkack said:
Earth atmosphere?
In normal weather, Sun on horizon is refracted 35 minutes upwards. So that Sun which has just set in West is geometrically 35 minutes under horizon.
Suppose that some weather phenomenon should cause the refraction to suddenly increase from 35 minutes to 65 minutes. Then Sun would be seen to rise in the west. Of course, Sun would continue setting and the weather phenomenon might also pass, so Sun would set again.

But do such weather phenomena exist, which might cause the refraction to change so much and so fast?
To return to this point: (1) This is 35 arcminutes, or about 4 (temporal) minutes of Earth rotation. (2) Doubling this effect would require increasing the atmospheric density by ~40% [I think, or maybe ~ 100%?] in those 4 minutes of time.

If you see such an effect, it can't be caused by weather. Extreme storms cause atmospheric density to change by ~ 10% over a few hours. So it's presumably caused by a dinosaur-extinction meteoric event.

The corresponding overpressure will travel at somewhat more than the speed of sound (~1000 km/hr), which is just about the Earth's linear rotation speed at mid-latitudes. So it will reach you in less than 4 minutes, and you will die before the second sunset finishes. I hope it's a beautiful one, at least.
 
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  • #35
Ashraf Siddiqui said:
Please forget what I believe. I simply want to know probability of sunrise in the west. May be some other thing would cause this astronomical phenomenon - An optical illusion would be created by ?

Huge mirrors could do it. Maybe 2 mirrors with 1.7 km radius with one orbiting at 380km. You would need to go slightly larger to compensate for any angles. Something much less bright than the Sun could resemble the Sun setting. Also a bent mirror could focus light so something smaller than the Sun's angular diameter could appear just as bright. If you want the pink/purple across the horizon effect you could use an array of small mirrors. Not sure why we would do that. Could also put a mirror on a balloon, tall building, helicopter or mountain and reflect the sunset. There is no need for the mirrors to be in the west.

The town of Rjuken in Norway and Viganella in Italy have a artificial suns in the winter. Should work at sunrise for some part of the year. They are set up to bring in a noon sun.

You can buy lights that make artificial sunrises for an alarm. It is supposed to help you wake up. Here is a mechanical artificial sunrise. You could set that in the north and south side of your room too.

Mar's moon Phobos rises in the west, so does the international space station.

In operation Hardtack Teak the USA detonated a nuclear missile in the atmosphere. At some places on the horizon it would have somewhat resembled a sunrise.

There is also atmospheric effects that cause light to distort or flicker. Stars twinkle. Here is a video of a green flash. I would not say that the sun "rises again" but the edge can go over the horizon and briefly reappear.
 

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