How long is a galactic year?

Aug 31, 2020
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Eventually what is left of the Sol system gets sucked into the super black hole at the center of the galaxy. Poof.
 
Aug 31, 2020
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It is an informative article. But,in my opinion the appropriate title of the article should have been ' How long is a sun year ? 'because the article describes the revolution of the sun around Milkyway Galaxy in around 230 ‐240 million years and not the revolution of the Milkyway Galaxy around any cosmic object.
 
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Aug 31, 2020
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It is an informative article. But,in my opinion the appropriate title of the article should have been ' How long is a sun year ? 'because the article describes the revolution of the sun around Milkyway Galaxy in around 230 ‐240 million years and not the revolution of the Milkyway Galaxy around any cosmic object.
And now there was some article about the Andromeda galaxy's halo that is 'nudging' the Milky Way. I will have to read up on that. But yea, I did consider that galaxies could rotate, but our deepest picture of the universe shows them in linear direction, no rotation... :D
 
Aug 31, 2020
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The solar system is actualy vibrating creating TIME and space time cycle ripples, one needs to have in depth knowledge of geometry to understand just how this all works. Each planet has its own pulsating ripple cycle "image" measure and the earth has the longest becouse its expanding and contracting both ways held in balance . The ancient gave names to all these images as being GODS. The first being Mercury or Hermes, (greek or roman) the fast one. other cultures having different names) but in overall time they are all in the same time frame, but in space ripple or viberation cycle time each is different. Using base 10 math is (9 planets and 1 sun) the overall time frame cycle is 86 (+-1) =87. A gravitational pulsating black hole exist in the centre expanding and contracting over time so the solar system is in affect always remains in balance but appears to move becouse of the ripples (expanding/contracting) this "differential" equation has the measure of (Pi). Eventualy all space time will fill up due this rippling motion and so will the empty VOID ..ie - Moment of completion as from dot to BLOT as the ancients referred to it. ONE can think of it as being like the nautilus shell found in the sea when the life within it has ended and gone leaving behind only the skeleton shell which It has built around its SELF as with all other creatures including human beings. The great pyramid of giza would be another example of such a thing no body remains have ever been found within it becouse its motivating creator no longer exists except in writtem records like the pharaoh but he never actualy built it himself skilled workers did. Life is an illusion functioning on differing levels in material, Spiritual and metophisical form, all this can be found in genesis in the bible. Science and religion functioning together using TIME and space time.
True,but...
 
Aug 31, 2020
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Dear Grant-Currin,

First, I want to remind you about Vera Rubin's greatest work in studied Andromeda galaxy. She found that the movement of those stars is in the same angular speed. That's means, they move like a plate of pizza. All stars are in the same formation in a plate of the galaxy.
Contradict to planetary movement in our solar system. Despite the farthest planet to Sun as the center moves slower, the farthest stars to the center of the galaxy will move faster. By that founding, she proposed the Dark Energy and the Dark matter. (CMIIW).

In the galaxy-wide, we should use RAM (Revolve Around the Middle) as the galactic-wide time. In our Solar System, 1 RAM is about 220-230 million Earth years.

If you want to meet someone from another star system, you must use the same time calculation that can be used galaxy-wide.
 
Aug 31, 2020
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Dear Grant-Currin,

First, I want to remind you about Vera Rubin's greatest work in studied Andromeda galaxy. She found that the movement of those stars is in the same angular speed. That's means, they move like a plate of pizza. All stars are in the same formation in a plate of the galaxy.
Contradict to planetary movement in our solar system. Despite the farthest planet to Sun as the center moves slower, the farthest stars to the center of the galaxy will move faster. By that founding, she proposed the Dark Energy and the Dark matter. (CMIIW).

In the galaxy-wide, we should use RAM (Revolve Around the Middle) as the galactic-wide time. In our Solar System, 1 RAM is about 220-230 million Earth years.

If you want to meet someone from another star system, you must use the same time calculation that can be used galaxy-wide.
I'm not the brightest, but i just ripped a J & was thinkin', like carl sagan would... now if the water is going down the drain towards the milky way center so to speak, was a galactic year longer on its last year around the center? Will the galactic year progressively get shorter as we whip around faster towards the center?
 
Aug 31, 2020
2
1
15
I'm not the brightest, but i just ripped a J & was thinkin', like carl sagan would... now if the water is going down the drain towards the milky way center so to speak, was a galactic year longer on its last year around the center? Will the galactic year progressively get shorter as we whip around faster towards the center?
Indeed, there was a problem when Vera Rubin face that Newtonian gravity did not work on the galaxy scale. Because stars in a galaxy revolve around the middle in the same angular speed. That's why they developed the Modified Newtonian Dynamics (MOND) https://link.springer.com/article/10.12942/lrr-2012-10

"Rubin studied this problem and her results led to three conclusions in the astronomy community. The first was that perhaps gravity was not the only force holding galaxies together. The second was that Newtonian gravity may not function on large scales as it does here on Earth. The last was that there may be large amounts of unseen matter contributing to an increased mass, which would hold the galaxy together. This is the most popular theory, and Rubin’s calculations show that if this is the case, there must be at least six times as much dark matter compared to regular matter. This was a major breakthrough in astronomy. "

Galaxy rotation curve


And this illustration might help you to understand what they guessed how the Dark Matter works.
 
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Jan 3, 2020
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Aside from the Sun orbit time in the Milky Way, the article seems oddly confused or sloppily put together from some similar article.

Sun and Earth are equally old against such a period (since we can date Earth latest to the Moon forming impact 50 million years after the Sun formed), at about 4,500/220 = 20 "years". (The universe would be 13,800/220 = 63 "years".)

The 16 "years" = 16*220 = 3,500 million years is the age of the first more broadly accepted fossils.
 
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Jan 3, 2020
152
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It is an informative article. But,in my opinion the appropriate title of the article should have been ' How long is a sun year ? 'because the article describes the revolution of the sun around Milkyway Galaxy in around 230 ‐240 million years and not the revolution of the Milkyway Galaxy around any cosmic object.
And now there was some article about the Andromeda galaxy's halo that is 'nudging' the Milky Way. I will have to read up on that. But yea, I did consider that galaxies could rotate, but our deepest picture of the universe shows them in linear direction, no rotation... :D
Besides the Earth/Sun age confusion [my previous comment], taking the orbital period as "year" is not really relevant on a galactic scale same as a mean solar rotation of 27 Earth days [ https://www.nasa.gov/mission_pages/sunearth/science/solar-rotation.html ] do not say much on a solar "day". A better clock for Sun is its 11 year main magnetic (sun spot) cycle.

The size of the Milky Way has grown some lately. Better observations has increased its disk diameter to about 200 thousand light years [ https://www.nasa.gov/mission_pages/sunearth/science/solar-rotation.html ]. Similarly modeling gravitational effects has given the dark matter gas halo as about 2 million light years in diameter [ https://www.sciencenews.org/article/astronomers-have-found-edge-milky-way-size ], which is a good fit to the recent observations of the normal matter gas halo of the similarly massed Andromeda galaxy of 2-3 million light years diameter [ https://www.space.com/andromeda-galaxy-halo-hubble-telescope-discovery.html ].

With 2.5 million light years distance between Andromeda and Milky Way [ibid] it should mean that the normal matter gas - which is blown away and partly circulated back through interaction with the galactic core (mostly the super massive central black holes) - is already interacting. And perhaps even the gravitationally bound dark matter gas also feels the gravitational effects of the nearby halo (including the local "clump" building we see in dark matter [ https://www.nasa.gov/feature/goddard/2020/hubble-detects-smallest-known-dark-matter-clumps/ }).

The "linear" flow of galaxies derives from that they mostly formed in cosmic filaments, the initial fluctuations in energy and momentum under inflation that impressed on the hot big bang that builds "the cosmic web". As the universe ages the filaments have collapsed under gravitation and galaxies has streamed along them towards the galaxy clusters in the nodes where filaments meet. So that is why galaxies in some local projection may seem to line up.

A fun effect is that it seems to explain the galaxy rotation distribution. Primordial galaxies formed from gas that tended to rotate with axes along the filaments, but as galaxies stream along a filament they merge and the rotation axis distribution now start to tend to be perpendicular to the filament axis. (Milky Way is a fairly mature galaxy and is purportedly tilted in between the two end cases.) This is explaining some of the funny infalling dwarf galaxy distributions who seem ordered, but in this physics would be.
 
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Jan 3, 2020
152
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I'm not the brightest, but i just ripped a J & was thinkin', like carl sagan would... now if the water is going down the drain towards the milky way center so to speak, was a galactic year longer on its last year around the center? Will the galactic year progressively get shorter as we whip around faster towards the center?
The solar system galactic orbit is, as previous comments note, fixed by the galactic dark matter halo which dominates gravitationally (on average 5 times more dark matter than "light" matter in the universe) and extends 5 - 10 times further than the visible disk. The dark matter halo is not really efficiently cooled (since it is, well, dark) and will settle over cosmologically vast times, many times the current age of the universe. The Milky Way and Andromeda will form the "Milkymeda" galaxy way before then.

What is continually settling into the galaxy but also "jetted out" to some degree is the "light"matter gas. It seems such gas recirculation decides star formation rates, so some of the aging of a galaxy (modulo galaxy mergers and fresh intergalactic gas infall).
 
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