On Astrophysical Questions 100

From birth to destruction, stars go through the aggregation of matter to form stars, and the temperature rises under the action of gravity and begins hydrogen fusion, and the time of fusion is different according to the size of its mass, the fusion time is long for small masses, and the fusion time is short for large masses. The ultimate fate is that there are white dwarfs, red giants, and neutron stars. Black hole.

First the star will be fused due to gravity, the thermal motion after fusion will balance with gravity, and then for a long time in the period called the main sequence period, this period is the longest, and then due to the exhaustion of hydrogen fuel in the center, it begins to expand to the outer layer, at first the surface temperature of the star is very high, but the hydrogen is not consumed, so it will expand due to thermal motion, forming a red giant, and finally it will form dwarf stars, neutron stars, magnetars and other high-density celestial bodies, the formation of celestial bodies is mainly related to the mass of the star, For example, supermassive stars will form black holes after a very large supernova**, beyond the principle of degenerate states in quantum, the orthodox theory is like this, but whether it is true or not has to wait for experiments or observations to confirm.

Since the beginning of the universe, the temperature is very high, only hydrogen exists, and then as time goes by, the temperature decreases, and nuclear fusion occurs between hydrogen and hydrogen to produce helium, and then as time goes by, the temperature gets lower and lower, and it gradually fuses into other elements. Due to the gravitational attraction between objects, the celestial bodies are gradually approaching, and with a series of changes after the celestial bodies are approaching, the density of the celestial bodies will become larger and larger, and white dwarfs and the like will be formed, and white dwarfs attract each other ,...After a series of changes, it will eventually end up with a black hole, which is what we write in our book.

You have blocked all the answers, and I am not the creator, so I can only recommend you to read "A Brief History of Time" to find the answer for yourself.

Astrophysics is a branch of physics and astronomy. It studies the nature of objects in the sky and their interactions. Sky objects include stars, galaxies, planets, outer planets, the whole of the universe.

Astrophysics is divided into two main parts: observational astrophysics and theoretical astrophysics.

Since the object at this point (the first Lagrange point) is attracted by both the Earth and the Moon, it has the same period as the Moon but has a different radius. So it's clear that ABC is wrong, and D is correct.

A: Because the space station is located between the Earth and the Moon, the radius is smaller than that of the Moon, so the linear velocity is definitely less than that of the Moon.

b: Because the periods are the same, the angular velocities are equal.

c: In the same way, the angular velocity of a is the same, and the centripetal acceleration with a large radius is large. f=mw rd: If the gravitational pull of the Moon on the object is greater than that of the Earth, the object will revolve around the Moon or fly towards the Moon without the Earth's bondage. So D is right.

The gravitational pull on the Moon on the same object is 1 6So the gravitational pull of the Earth is greater than that of the Moon.

In a system consisting of two celestial bodies, it is inferred that there are 5 Lagrangian points (L1 L5), where L1 is on and between the lines of the two bodies, M1 and M2. There is no doubt that this is an unstable Lagrange point. Assuming that M1 is the Earth and M2 is the Moon, then L1 is at the midpoint between the Earth and the Moon, and because the mass of M1 is greater than the mass of M2, the gravitational pull of the Earth on point L1 is greater than that of the Moon on point L1.

In fact, the gravitational equilibrium point between the Earth-Moon line is located close to the Moon, which is the fulcrum of the levers with different masses on both sides but equilibrium.

Why do planets rotate in the same direction?

Why are the orbits of the planets nearly coplanar?

Why do planets orbit nearly circular but elliptical?

Please refer to the Kant-Laplace Nebula Theory. The doctrine of Condraplas is also the basis of the modern nebula doctrine. He explained the three problems that the landlord said very well.

As for why the comet's orbit is elliptical, please refer to the cause of the comet.

Refer to the section on the origin of comets.

Most comets in the solar system were originally objects in the Oort cloud, and were shaken by the gravitational pull of the objects in the solar system and the disturbance of extrasolar planets, and such comets are likely to become comets with elliptical orbits.

There is also a kind of comet that enters the solar system and never returns, this kind of comet is accidentally close to the solar system, and then thrown out by the sun's gravity, its orbit is close to the parabola.

You know gravity, right? So think about it, why aren't planets sucked in by the sun? The reason for this is because the geomagnetic field of each planet produces a stable magnetic field, figuratively speaking, it is several bar magnets, with s on the top and n on the bottom.

Not necessarily this way, but in general this is the principle of this). When planets were first formed, they were caused by the gravitational attraction of cosmic dust, which caused friction and further attraction, and finally formed planets. Therefore, planets tend to be charged (e.g., the Earth is positively charged) and as the Earth is absorbed by the Sun, a magnetic field (electromagnetism) is generated, which in turn produces a revolution (the same principle as an electric motor).

Geomagnetism moves in the Sun's magnetic field, producing centrifugal force that balances with gravity (supposedly related to the distance between stars driven by dark energy), so that the Sun's magnetic field forms a stable whole with the magnetic fields of each planet, thus resisting invading stars. I think it may be because it's almost flat that it can be balanced. Note that not all stars rotate in the same direction, for example, Venus is opposite to Earth, possibly because Venus is positively charged, resulting in a different magnetic field.

Next question. In fact, the gravitational pull of stars can change at different angles, for example, on Earth, the closer to the poles, the greater the gravitational force. In the same way, you can think of the cause of the ellipse, of course, it could also be the change of the sun's own energy over time, or the interference of external energy, but the main reason is the first one.

Comets, which are susceptible to interference, have low energy of their own, are susceptible to external gravitational forces, are close to massive stars, are elliptical, close to those with low gravitational force, and are circular. (If you don't understand the question, don't rush to end the question, you can add it, I will continue to answer).

1 Because it is determined by the rotation of the stars.

2 Because it's also determined by the rotation of the stars Why do you say that the wheels of bicycles stand up when they move.3 Think about the hula hoop.

4 Because it's faster.

The gravitational force between the Earth and the Sun is: F1 = M1M2G r 2 The Earth relies on this gravitational force as the centripetal force for revolution: F2 = M1 V 2 RF1 = F2 = F

According to this theory, a long time ago, g was larger than it is now, then the gravitational force between the earth and the sun is greater than it is now, when the gravitational force becomes larger, then the existing velocity is not enough to maintain sufficient centripetal force, and the earth is close to the sun, so the radius of revolution becomes smaller;

At this point, since f2 = m1 v 2 r, when r becomes smaller and f2 becomes larger, then v must become larger in order to provide sufficient centripetal force.

When v becomes larger, r becomes smaller, and t becomes smaller according to the period t = 2 * pi * r v.

So, a long time ago, the revolution radius was smaller than it is now, and the revolution period was smaller than it is now.

The revolution radius was smaller than it is now, and the revolution period was smaller than it is now.

The cycle is getting bigger.

The revolution radius becomes smaller.

Correct answer: ad

The larger the orbital radius, the smaller the orbital velocity of the satellite, so a pair; p is the orbit is the perigee of the ellipse, and the velocity is greater, so b is wrong; From Newton's second law, it can be seen that a = f leads to m, no matter which point p in the orbit, the gravitational attraction of the moon to the satellite is the same, and it is the same satellite, the mass is also the same, so the acceleration is also the same, so c is wrong, the orbit is higher than the orbit, when launching the satellite, the higher the orbit, the more energy required, then according to the conservation of energy, the higher the orbit of the satellite has more mechanical energy, so d is right.

1. In the process of condensation and formation of objects, the combined action of gravitational force, centrifugal force and surface tension is the formation of an approximate spherical shape.

2. The planet generates a magnetic field through the generator effect of an electric current flowing in a conductive liquid nucleus, so the conditions for generating a magnetic field are: liquid core, conductive, and rotating.

1.You're right, the condensation of celestial bodies is the result of the combined action of gravity, centrifugal force, and surface tension to form a sphere.

2.This may be mainly due to the small mass of the planetary moons, and the other thing that has to do with their material composition.

1。Wa, you've got that in mind. You are absolutely correct.

2。Even if the earth and the sun are rotating and orbiting, there is no magnetic field. They just take up a portion of the 4D space.

So there are collapses around it (the planet). That will have a chance to form a centripetal force with other planets.