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Philosophaie
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Why do the planets travel in elliptical orbit around the Sun?
Philosophaie said:Why does the south pole (Magnetic Positive) tilt towards the Sun at the periapsis (when the Earth is closest to the Sun) and away from the Sun at the apiapsis (when Earth is furthest from the Sun). Is this gravitational or magnetic forces?
Philosophaie said:Then tell me the pattern of the rotational tilt if it is not due to the gravitational or magnetic forces.
You mean on a month to month basis? Nothing. The tilt is essentially constant.Philosophaie said:Yes I understand that the spin has only minor influences from sun and gravitation. What influences the tilt of the planet?
D H said:Trajectories that result from inverse square central force must follow a conic section. Circular orbits are but one kind of conic section. Other conic sections are ellipses, parabolas, and hyperbolas. Planets do not have circular orbits; they have elliptical orbits. No surprise here: a perfectly circular orbit is a statistical impossibility...
You are mistakenly assuming that just because Earth's periapsis passage currently is nearly coincident with the winter solstice that that is the way things have always been. That is not the case. The Earth's anomalistic year (the time between successive periapsis passages) is 25.1 minutes longer than the Earth's tropical year (he time between successive vernal equinoxes). That the Earth's periapsis passage currently is nearly coincident with the winter solstice is a coincidence. A couple of thousand years from the Earth's periapsis passage will happen to occur in February. A few thousand more, it will occur in April.Philosophaie said:Why does the south pole (Magnetic Positive) tilt towards the Sun at the periapsis (when the Earth is closest to the Sun) and away from the Sun at the apiapsis (when Earth is furthest from the Sun). Is this gravitational or magnetic forces?
A circular orbit is a mathematically impossible in the sense that the probability of picking some exact number from a continuous random distribution with a continuous CDF is identically zero. To have a circular orbit the velocity vector must be exactly orthogonal to the position vector (an event of measure zero) and the magnitude of the velocity vector must have some exact value (another event of measure zero).LURCH said:Impossible, or just very improbable? Since a circle is an elipse, I would have thought that it was no more unlikely than any other degree of eccentricity.
LURCH said:Impossible, or just very improbable? Since a circle is an ellipse, I would have thought that it was no more unlikely than any other degree of eccentricity.
Again: tilt is constant. Ie, no maximum or minimum.Philosophaie said:Does the tilt have a period or a certain date it will be maximun or minimum?
No, it's not. The Earth's orientation changes with time; the changes are collectively called precession and nutation. The largest in magnitude and longest in period was first discovered by Hipparchus. Because the Moon's orbit about the Earth and the Earth's orbit around the Sun are inclined with respect to the Earth's equatorial plane and because the Earth is an oblate spheroid, the Moon and Sun exert torques on the Earth. The principal effect is the lunisolar precession, also called the precession of the equinoxes. The Earth's orientation approximately traces out a cone with a half angle of about 23.4 degrees (the obliquity of the ecliptic) and a period of 25,770 years.russ_watters said:Again: tilt is constant. Ie, no maximum or minimum.
I was still talking in the short term - month to month timeframe (from my previous post). It appears to me that the OP is asking about month-to-month changes. Over that timeframes it is effectively constant.D H said:No, it's not. The Earth's orientation changes with time; the changes are collectively called precession and nutation.
An elliptical orbit around the Sun is a type of orbit in which an object, such as a planet or spacecraft, moves around the Sun in an oval or elliptical shape. This means that the distance between the object and the Sun varies throughout its orbit.
An elliptical orbit is different from a circular orbit in that it is not a perfect circle. In a circular orbit, the distance between the object and the Sun remains the same throughout the orbit. In an elliptical orbit, the distance varies, with the object being closer to the Sun at one point and farther away at another point.
The shape of an object's orbit is determined by its velocity and the force of gravity acting upon it. In the case of an elliptical orbit, the object's velocity is such that it is able to maintain a stable orbit while also being influenced by the gravitational pull of the Sun.
The characteristics of an elliptical orbit include an eccentricity, which is a measure of how elongated the orbit is, and a periapsis and apoapsis, which are the closest and farthest points between the object and the Sun in its orbit.
No, an object in an elliptical orbit cannot collide with the Sun unless its orbit is disrupted by an external force. This is because the object's velocity and the gravitational pull of the Sun are balanced in such a way that it is able to maintain a stable orbit without falling into the Sun.