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Amazing Planetary Movements


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A simple image of the way the moon moves if we look at the solar system from directly above.  As the moon orbits the Earth and the Earth orbits the sun, the moon's movements become more complicated.  The moon takes about 27.3 days to orbit the earth, and the moon phases repeat about every 29.5 days.  The difference is due to the fact that as the moon orbits the earth, the earth is also moving around the sun.  It is the relative positions of the sun, earth, and moon that creates the phases of the moon that we observe.

 

If we add in the movement of the sun around the center of the galaxy, it creates a completely new picture.  Once again, we are taking a certain perspective.  This image is a view from directly above the galactic center.  The orbit of the sun around the center of the galaxy is estimated to take somewhere between 225,000,000 and 250,000,000 years.  The image below is an approximation of what you would see from directly above the galactic center.

 

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This is showing the movements of the moon around the earth, which is moving around the sun, which is moving around the galactic center.   None of these orbits are actually perfect circles but are actually more elliptical.  This, of course, is a simplified image.  The image shows the movements of the moon but only uses 16 circles.  An image showing between 225,000,000 and 250,000,000 would of course be ridiculously large.

 

Even more complicated would be trying to show the movement of the galaxy through space.  It would be a very complex image.  And these images are just from one viewpoint, above (or below) the galaxy, perpendicular to the plane of the galaxy.

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From another viewpoint, we get a different perspective from the one above.

 

https://www.google.com/search?q=helical+solar+system&client=ms-android-tracfone-us-rvc3&sca_esv=ec1c0fa4563bd641&source=android-browser&sxsrf=AHTn8zoy1RyTs7d0AcxGkLhAicpU3EuRIg%3A1744979003320&ei=O0QCaOqRE8Tep84P2uipwQ0&ved=0ahUKEwiqm4ityeGMAxVE78kDHVp0KtgQ4dUDCBA&uact=5&oq=helical+solar+system&gs_lp=Egxnd3Mtd2l6LXNlcnAiFGhlbGljYWwgc29sYXIgc3lzdGVtMgsQABiABBiRAhiKBTIGEAAYFhgeMgsQABiABBiGAxiKBTILEAAYgAQYhgMYigUyCxAAGIAEGIYDGIoFMgUQABjvBUjuP1DCCFinH3ABeACQAQCYAYsBoAGqCaoBBDEwLjO4AQPIAQD4AQGYAg2gAoIJwgIOEAAYgAQYsAMYhgMYigXCAggQABiwAxjvBcICCxAAGIAEGLADGKIEwgILEC4YgAQY0QMYxwHCAgUQABiABMICCxAuGIAEGMcBGK8BwgIaEC4YgAQY0QMYxwEYlwUY3AQY3gQY4ATYAQHCAggQABgWGAoYHsICCBAAGIAEGKIEmAMAiAYBkAYEugYGCAEQARgUkgcEMTAuM6AHi2CyBwM5LjO4B_wI&sclient=gws-wiz-serp#fpstate=ive&vld=cid:6a20f387,vid:0jHsq36_NTU,st:0

 

Is this model perfect?  NO!  In the video, he states that the heliocentric model of the solar system is wrong.  It isn't wrong, it is merely from a different perspective, a different viewpoint.  The heliocentric model of the universe works just fine from one perspective and the model shown above is fine from another perspective, and this video just shows the movement from a third perspective. 

 

The video is very nice but has its own flaws.  As the sun moves around the center of the galaxy, there is something of a wobble so that the sun is sometimes slightly above the galactic plane and is sometimes slightly below the galactic plane.  The video does show how the sun moves through space as it orbits the galactic center.  


Edited by Witness1970

corrected some spelling errors.
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Is time real?  This might sound like it is off topic, but is it really?

 

There have been science fiction programs about travelling through time.  But what is time really?

 

We measure time with movements of the heavenly bodies.  When the earth makes one rotation, it is called a day.  It actually takes 23 hours and 56 minutes for the earth to rotate one time, but since the earth is also moving around the sun, it affects what we observe to be a day.  When the earth makes a complete orbit around the sun, it is called a year.  It takes 365.2422 days for the earth to make one full orbit.  This means we need to use 97 leap years out of every 400 years to keep the seasons close to the same time of year.

 

Since our measurement of time is based on the movements of physical objects, time is really just another space dimension.  So, this post is still about planetary movements, since time is just a measure of the relative positions of objects as they move.

 

When we make appointments, it is said to use 4 dimensions.  A street address (which can be located using latitude and longitude) on the 4th floor meeting room, a measure of height (a 3rd dimension) and the time is 9:00 AM (a 4th dimension).  But when we say 9:00 AM, we are really describing time in terms of the position of the sun relative to our position.  This means that the time mentioned is just another description of the position of heavenly bodies relative to our position.  

 

No! We can never travel back through time.  The past does not exist except as a memory.

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Gravity travels at the speed of light.  If the black hole at the center of the galaxy suddenly disappeared objects would begin to drift away.  Anything within one (1) light-year would start to drift away after one year.  The solar system, which is approximately 25,000 light-years from galactic center would start to drift away after 25,000 years. The edge of the galaxy, which is approximately 50,000 light-years from galactic center would start to drift away after 50,000 years.

 

If you could observe this from a position 100,000 light-years from the center of the galaxy, everything would appear to start drifting away at exactly the same time.  The object that is 1 light-year from the center would start drifting away after one year but the light from that object would take another 99,999 years to reach us.  The solar system would start drifting away after 25,000 years and the light from the solar system would reach us after another 75,000 years. The objects at the edge of the galaxy would start drifting away after 50,000 and the light from those objects would take another 50,000 years to reach us.  Simply put we would see all these things 100,000 years after the black hole disappeared.  I am of course talking about the objects that are on the side of the galaxy nearest to us.  Other objects would take completely different calculations.

 

If the gravity from the center of the galaxy somehow diminished 30,000 years ago, our solar system would be reacting to the gravity that existed 25,000 years ago.  The edge of the galaxy would still be reacting to the gravity that existed 50,000 years ago since the gravity change has not reached out that far yet.

 

Mind-blowing thoughts!


Edited by Witness1970
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Raining diamonds on Uranus and Neptune:

 

It's raining diamonds

The idea of diamond rain was first proposed before the Voyager 2 mission which launched in 1977. The reasoning was pretty simple: We know what Uranus and Neptune are made of, and we know that stuff gets hotter and denser the deeper into a planet you go. The mathematical modeling helps fill in the details, like that the innermost regions of the mantles of these planets likely have temperatures somewhere around 7,000 kelvins (12,140 degrees Fahrenheit, or 6,727 degrees Celsius) and pressures 6 million times that of Earth's atmosphere.

Those same models tell us that the outermost layers of the mantles are somewhat cooler — 2,000 K (3,140 F or 1,727 C — and somewhat less intensely pressurized (200,000 times Earth's atmospheric pressure). And so, it's natural to ask: What happens to water, ammonia and methane at those kinds of temperatures and pressures?

With methane, in particular, the intense pressures can break the molecule apart, releasing the carbon. The carbon then finds its brethren, forming long chains. The long chains then squeeze together to form crystalline patterns like diamonds.

The dense diamond formations then drop through the layers of the mantle until it gets too hot, where they vaporize and float back up and repeat the cycle — hence the term "diamond rain."

 

EDIT: https://www.space.com/diamond-rain-atmosphere-uranus-neptune


Edited by Witness1970
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Most orbits are not circular.  They are elliptical. Circular orbits would be very rare.

 

The reason that most bodies in the universe would have elliptical orbits is because there are 2 forces that act on those objects.  The smaller body would continue in a straight line if not acted on by gravity from a larger body.

 

Using the sun and earth as examples.  The earth would continue moving in a straight line if not for the sun's gravity.  The earth is going fast enough to move away from the sun slightly.  Due to the law of conservation of angular momentum, as the earth moves away from the sun, it slows down.  Due to the earth slowing down, the gravity from the sun pulls it in closer and the earth speeds up again.  This causes the earth's orbit to be elliptical.

 

Will the earth's orbit ever be a perfect circle?  The earth has been in existence for an estimated 4.5 billion years.  The orbit is still elliptical.  Maybe someday several billion years in the future, the earth's orbit might be a perfect circle.  We can wait and see!


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For its 100th birthday, the Schrödinger equation, which describes how the quantum world behaves, is getting a glow-up. Physicists now ask what happens when the observer is part of that quantum world.

 

The Schrödinger equation, formulated by Erwin Schrödinger in 1925, is a fundamental equation in quantum mechanics that describes how the quantum state of a physical system evolves over time. As the equation approaches its 100th birthday, physicists are exploring its implications when the observer is part of the quantum world, raising questions about the nature of reality and the observer's role in the quantum state. This ongoing research reflects the ongoing relevance and significance of the Schrödinger equation in understanding quantum phenomena and its potential applications in various fields.

 

https://www.news.uzh.ch/en/articles/news/2025/schroedingers-legacy.html

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Earth's precession is a slow, continuous wobble of its rotational axis, completing a full cycle approximately every 26,000 years.
What is Earth's Precession?

Earth's precession, also known as axial precession, is the gradual shift in the orientation of Earth's axis of rotation. This motion causes the axis to trace out a conical shape over time, with a tilt of about 23.4°, known as the obliquity of the ecliptic, similar to the wobble of a spinning top (axial precession). The full precessional cycle takes roughly 26,000 years, during which the positions of the equinoxes slowly move westward along the ecliptic relative to the fixed stars. 
Wikipedia
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Causes of Precession
The primary cause of Earth's precession is the gravitational torque exerted by the Sun and Moon on Earth's equatorial bulge. Because Earth is not a perfect sphere but slightly flattened at the poles, the gravitational pull on the bulge generates a torque perpendicular to the axis of rotation, causing the axis to slowly rotate in space. Planetary gravitational influences also contribute slightly, causing planetary precession, but this effect is much smaller than the dominant lunisolar precession. 
Wikipedia
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Historical Discovery
The phenomenon was first identified by the Greek astronomer Hipparchus around 130 BC. By comparing his observations with older records, he noticed that the positions of the equinoxes had shifted by about 2° over 169 years, leading him to describe this motion as the precession of the equinoxes. This discovery explained why the "first point of Aries," marking the spring equinox, gradually moves through different constellations over millennia. 
NASA
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Effects of Precession
Pole Star Shift: The star currently near the north celestial pole, Polaris, will not always occupy this position. In the distant future, stars like Vega will become the north star. 
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Equinox Movement: The vernal equinox slowly shifts westward along the ecliptic at a rate of about 50.26 arc-seconds per year, affecting the alignment of calendars and celestial coordinates. 
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Astronomical Implications: Precession introduces a difference between the tropical year (based on the Sun) and the sidereal year (based on stars), which is important for precise astronomical observations and long-term climate studies. 
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Interaction with Other Cycles: Precession combines with other orbital variations, such as the 41,000-year tilt oscillation and 71,000-year orbital plane precession, influencing Earth's long-term climate patterns, including the Milankovitch cycles. 
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2 Sources
Modern Understanding
Today, precession is described in terms of general precession, which combines the precession of the equator (dominant) and the precession of the ecliptic (minor). Advanced techniques like very long baseline interferometry (VLBI) allow precise measurement of Earth's orientation relative to distant celestial objects, improving our understanding of precession and its variations. 
Cambridge University Press & Assessment

In summary, Earth's precession is a slow, gyroscopic wobble caused by gravitational forces on its equatorial bulge, with profound effects on celestial navigation, the position of the pole star, and long-term astronomical and climatic cycles.

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Milankovitch cycles

 

https://science.nasa.gov/science-research/earth-science/milankovitch-orbital-cycles-and-their-role-in-earths-climate/

 

https://science.nasa.gov/science-research/earth-science/why-milankovitch-orbital-cycles-cant-explain-earths-current-warming/

Milankovitch (Orbital) Cycles and Their Role in Earth’s Climate

The headshot image of NASA Science Editorial Team

NASA Science Editorial Team

Feb 27, 2020
Article
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  • (The pictures didn't work in the post.  You can view the article with pictures on the link)
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Our lives literally revolve around cycles: series of events that are repeated regularly in the same order. There are hundreds of different types of cycles in our world and in the universe. Some are natural, such as the change of the seasons, annual animal migrations or the circadian rhythms that govern our sleep patterns. Others are human-produced, like growing and harvesting crops, musical rhythms or economic cycles.

Cycles also play key roles in Earth’s short-term weather and long-term climate. A century ago, Serbian scientist Milutin Milankovitch hypothesized the long-term, collective effects of changes in Earth’s position relative to the Sun are a strong driver of Earth’s long-term climate, and are responsible for triggering the beginning and end of glaciation periods (Ice Ages).

Specifically, he examined how variations in three types of Earth orbital movements affect how much solar radiation (known as insolation) reaches the top of Earth’s atmosphere as well as where the insolation reaches. These cyclical orbital movements, which became known as the Milankovitch cycles, cause variations of up to 25 percent in the amount of incoming insolation at Earth’s mid-latitudes (the areas of our planet located between about 30 and 60 degrees north and south of the equator).

The Milankovitch cycles include:

  1. The shape of Earth’s orbit, known as eccentricity;
  2. The angle Earth’s axis is tilted with respect to Earth’s orbital plane, known as obliquity; and
  3. The direction Earth’s axis of rotation is pointed, known as precession.

 

 
Play Video
Credit: NASA/JPL-Caltech

Eccentricity – Earth’s annual pilgrimage around the Sun isn’t perfectly circular, but it’s pretty close. Over time, the pull of gravity from our solar system’s two largest gas giant planets, Jupiter and Saturn, causes the shape of Earth’s orbit to vary from nearly circular to slightly elliptical. Eccentricity measures how much the shape of Earth’s orbit departs from a perfect circle. These variations affect the distance between Earth and the Sun.

Eccentricity is the reason why our seasons are slightly different lengths, with summers in the Northern Hemisphere currently about 4.5 days longer than winters, and springs about three days longer than autumns. As eccentricity decreases, the length of our seasons gradually evens out.

The difference in the distance between Earth’s closest approach to the Sun (known as perihelion), which occurs on or about January 3 each year, and its farthest departure from the Sun (known as aphelion) on or about July 4, is currently about 5.1 million kilometers (about 3.2 million miles), a variation of 3.4 percent. That means each January, about 6.8 percent more incoming solar radiation reaches Earth than it does each July.

When Earth’s orbit is at its most elliptic, about 23 percent more incoming solar radiation reaches Earth at our planet’s closest approach to the Sun each year than does at its farthest departure from the Sun. Currently, Earth’s eccentricity is very slowly decreasing and is approaching its least elliptic (most circular), in a cycle that spans about 100,000 years.

The total change in global annual insolation due to the eccentricity cycle is very small. Because variations in Earth’s eccentricity are fairly small, they’re a relatively minor factor in annual seasonal climate variations.

 
Play Video
Credit: NASA/JPL-Caltech

Obliquity – The angle Earth’s axis of rotation is tilted as it travels around the Sun is known as obliquity. Obliquity is why Earth has seasons. Over the last million years, it has varied between 22.1 and 24.5 degrees with respect to Earth’s orbital plane. The greater Earth’s axial tilt angle, the more extreme our seasons are, as each hemisphere receives more solar radiation during its summer, when the hemisphere is tilted toward the Sun, and less during winter, when it is tilted away. Larger tilt angles favor periods of deglaciation (the melting and retreat of glaciers and ice sheets). These effects aren’t uniform globally -- higher latitudes receive a larger change in total solar radiation than areas closer to the equator.

Earth’s axis is currently tilted 23.4 degrees, or about half way between its extremes, and this angle is very slowly decreasing in a cycle that spans about 41,000 years. It was last at its maximum tilt about 10,000 years ago and will reach its minimum tilt about 10,000 years from now. As obliquity decreases, it gradually helps make our seasons milder, resulting in increasingly warmer winters, and cooler summers that gradually, over time, allow snow and ice at high latitudes to build up into large ice sheets. As ice cover increases, it reflects more of the Sun’s energy back into space, promoting even further cooling.

 
Play Video
Credit: NASA/JPL-Caltech

Precession – As Earth rotates, it wobbles slightly upon its rotational axis, like a slightly off-center spinning toy top. This wobble is due to tidal forces caused by the gravitational influences of the Sun and Moon that cause Earth to bulge at the equator, affecting its rotation. The trend in the direction of this wobble relative to the fixed positions of stars is known as axial precession. The cycle of axial precession spans about 25,771.5 years.

Axial precession makes seasonal contrasts more extreme in one hemisphere and less extreme in the other. Currently perihelion occurs during winter in the Northern Hemisphere and in summer in the Southern Hemisphere. This makes Southern Hemisphere summers hotter and moderates Northern Hemisphere seasonal variations. But in about 13,000 years, axial precession will cause these conditions to flip, with the Northern Hemisphere seeing more extremes in solar radiation and the Southern Hemisphere experiencing more moderate seasonal variations.

Precession does affect seasonal timing relative to Earth's closest/farthest points around the Sun. However, the modern calendar system ties itself to the seasons, and so, for example, the Northern Hemisphere winter will never occur in July. Today Earth’s North Stars are Polaris and Polaris Australis, but a couple of thousand years ago, they were Kochab and Pherkad.

There’s also apsidal precession. Not only does Earth wobble on its rotational axis, but Earth’s entire orbital ellipse – that is, the oval-shaped path Earth follows in its orbit around the Sun — also wobbles irregularly, primarily due to its interactions with Jupiter and Saturn. The cycle of apsidal precession spans about 112,000 years. Apsidal precession changes the orientation of Earth’s orbit relative to the ecliptic plane.

The combined effects of axial and apsidal precession result in an overall precession cycle spanning about 23,000 years on average.

A Climate Time Machine

The small changes set in motion by Milankovitch cycles operate separately and together to influence Earth’s climate over very long timespans, leading to larger changes in our climate over tens of thousands to hundreds of thousands of years. Milankovitch combined the cycles to create a comprehensive mathematical model for calculating differences in solar radiation at various Earth latitudes along with corresponding surface temperatures. The model is sort of like a climate time machine: it can be run backward and forward to examine past and future climate conditions.

Milankovitch assumed changes in radiation at some latitudes and in some seasons are more important than others to the growth and retreat of ice sheets. In addition, it was his belief that obliquity was the most important of the three cycles for climate, because it affects the amount of insolation in Earth’s northern high-latitude regions during summer (the relative role of precession versus obliquity is still a matter of scientific study).

He calculated that Ice Ages occur approximately every 41,000 years. Subsequent research confirms that they did occur at 41,000-year intervals between one and three million years ago. But about 800,000 years ago, the cycle of Ice Ages lengthened to 100,000 years, matching Earth’s eccentricity cycle. While various theories have been proposed to explain this transition, scientists do not yet have a clear answer.

Milankovitch’s work was supported by other researchers of his time, and he authored numerous publications on his hypothesis. But it wasn’t until about 10 years after his death in 1958 that the global science community began to take serious notice of his theory. In 1976, a study in the journal Science by Hays et al. using deep-sea sediment cores found that Milankovitch cycles correspond with periods of major climate change over the past 450,000 years, with Ice Ages occurring when Earth was undergoing different stages of orbital variation.

Several other projects and studies have also upheld the validity of Milankovitch’s work, including research using data from ice cores in Greenland and Antarctica that has provided strong evidence of Milankovitch cycles going back many hundreds of thousands of years. In addition, his work has been embraced by the National Research Council of the U.S. National Academy of Sciences.

Scientific research to better understand the mechanisms that cause changes in Earth’s rotation and how specifically Milankovitch cycles combine to affect climate is ongoing. But the theory that they drive the timing of glacial-interglacial cycles is well accepted.


Edited by Witness1970
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