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25

No, the sun won't ever become a black hole. The choice between the three fates of stars (white dwarf, neutron star, black hole) is entirely determined by the star's mass. A star on the main sequence (like most stars, including our sun) is constantly in a balance between the inward pressure of gravity and the outward pressure of the energy generated by ...


10

My understanding is that the Earth's axis points in the same direction in space during its entire orbit around the sun. And this is what causes our seasons. The second statement is correct. The axial tilt is the primary driver of the seasons. The first statement is not exactly correct. There is a small but persistent change in the orientation of the ...


7

Picture the Earth as a small ball suspended in midair, not moving, although it's rotating on its axis. Unless forces are applied to it, absolutely nothing will happen. That's conservation of energy (or momentum; you can work with it either way). Earth will not spontaneously start moving in one direction because that would violate conservation of ...


5

No, the sun is too small to become a black hole. There is a mass limit, called the Chandrasekhar limit, after which the star becomes a white dwarf. The limit is about 1.44 masses of our Sun. Then, the white dwarf will create a black hole after running out of fuel and collapsing on itself. So the sun will just expand into a gas giant, then shrink to a white ...


4

The changing angle between sun and moon does cause some slight nutation in the earth's axis of rotation over an 18.6 year period. In the case of the Earth, the principal sources of tidal force are the Sun and Moon, which continuously change location relative to each other and thus cause nutation in Earth's axis. The largest component of Earth's nutation ...


3

You know, the first time someone told me this, I was absolutely certain they were confused, ignorant, or otherwise mistaken, and I told him he had his facts wrong. To be precise, we were talking about an observer on the equator. I maintained that the Sun would rise due east and set due west, all year round. He said no. What gave me pause, though, is that ...


2

I should give credit here to @honeste_vivere, who pointed out to me today that there have been recent studies excited by some extremely large coronal mass ejections that were classed as "near misses" in terms of causing major disruption. Of particular interest to you would be the event of July 2012 discussed by Baker et al. (2013). I quote from the paper " ...


2

The Earth acts like a massive gyroscope. A tremendous force would be required to change the orientation of the axis. While forces are certainly exerted, they are not large enough to cause appreciable change in the orientation of the axis as the Earth falls/orbits about the Sun. As you indicate, the orientation of the axis is responsible for the change in ...


2

@DavidHammen is essentially correct. According to stellarium, the Sun gets as high as 89 58' 48":


2

Lets Keep things simple. Below is a picture of the orbit of the Earth. I take the question to mean why the axis doesn't point toward the Sun all the time. The answer comparing the Earth to a Gyroscope is the easiest to use. The spinning effect on the axis does cause a force that helps keep the Earth's axis at a 23.5° angle (Approx) there is a slight wobble ...


1

Because the Sun's gravitational pull on Earth is (nearly) uniform, it doesn't tilt the Earth, it only pulls it as a whole, without affecting the Earth's spinning around its own axis. The Earth's radius is ~ 6,400 km, the distance to the Sun is ~ 150,000,000 km, and the gravitational force diminishes as a square of a distance, so the ratio in the pull on ...



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