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So please show me one star that the gravity of the galactic disc pulls it inwards.
QuoteQuote from: Dave Lev on Today at 16:37:48Do we see any star that is falling into the galactic disc from outside?We see entire galaxies of stars falling into each other.How could we hope to spot a single star doing it? We have only been looking in detail at the sky for 100 years or so.So, no star has been seen to move more than 100 light years.That's time to over about 1/500 of the diameter of the Milky way.It's unlikely that we would spot it.
Quote from: Dave Lev on Today at 16:37:48Do we see any star that is falling into the galactic disc from outside?
If gravity pushed then orbits would not happen.We would not be here.
If gravity was not pulling it in then it would no longer be in the galaxy.
I would like to add that even if you have one million asteroids orbiting at 10R and you try to shoot them randomly in the direction of earth, It is quite clear to me that even if they hit with each other the chance that one of them will set a circular orbit at R is virtually Zero.
Based on Newton (V= M G /R^2), in order to set it radius R its velocity should be 10^-2 V = about 3.15VV is the velocity at 10R.So, if we wish to decrease the circular orbit radius by 10 we must increase the velocity by 3.15
I claim that in any direction/velocity that you would push (from 10R in the direction of the Earth) this asteroid it would never set a circular orbit around the earth at lower radius.
2.Circular orbit - Let's assume that something had been created. The chance to get an circular orbital system between two objects that came from the deep space in the direction of each other is virtually zero.
3. Increasing the Circular orbital velocity - Let's assume that a star (S2) is orbiting around a main object as a SMBH.
This is my point of view
Do we see any star that is falling into the galactic disc from outside?Why we see so many Meteors falling on earth due to gravity and NOT EVEN ONE STAR falling into the galactic disc?
The cluster of 250 stars are rotating with the Milky Way's galactic disk, where most of the galaxy's stars are located. But the Nyx stars are also moving toward the center of the galaxy.
However, all the stars in the arms MUST be drifted outwards over time.
If we find a star that is heading towards our galaxy, all you will do is claim that it will eventually be pushed aside before it can enter. Any star that is already in our galaxy, on the other hand, will be one that you claim never came from outside in the first place. For example, I can link you to this source about stars in our galaxy that probably came from outside of it, but you will simply claim that they originated in our own galaxy instead, won't you? https://www.cnn.com/2020/07/12/world/milky-way-stars-nyx-scn-trnd/index.html#:~:text=(CNN)%20Astronomers%20have%20found%20a,Greek%20goddess%20of%20the%20night.It's interesting to note what they say about the Nyx stars in that link, though:
He is going to say there is a mistake of some kind!
What kind of different chemicals our scientists have found in all of those 250 stars.
So how could it be that suddenly out of the blue there will be a cluster which gets to 6000 Ly above and below the galactic disc?
In any case, can we really measure their exact distance from the center of the galaxy and verify if they are really decreasing this radius?
Ha! I knew that you were going to be in denial!
Yes. We can know the direction that a star is moving by look at its redshift. You might want to look it up.
Quote from: Kryptid on 19/08/2020 15:56:27Ha! I knew that you were going to be in denial!Well, even our scientists don't know for sure the source of those stars. They clearly claim that: "further spectroscopic follow-ups (for example, from APOGEE-2, 4MOST and WEAVE) are needed to validate these conclusions."https://www.nature.com/articles/s41550-020-1131-2.epdf?sharing_token=e71tq_0EyC0COzNCPhCZW9RgN0jAjWel9jnR3ZoTv0Mq3fdQAZsAtY7Q6FxuakNtbhEKxyKIugF0KF-bGpOgZ-N5JSk5uFieMqObpFVfPmM06zaRRIpzeuO4q-y_nYNg_22QCyrOJFRwmp8TQFHO6uzbX7mBwCm9o3YehpbzhWOZ2h__FvoH7QKCV7to902XBJ4KZrw8OCIx5VTVGYnq8MgSxJRqcxLJU3McXJfyDydGU5qpTDI7xWu-PTKFNv0bi2JJb2Mg8x2HmSOigg5solRV_nUfYG5SH038jilL4_U%3D&tracking_referrer=edition.cnn.comFor the small subset for which we have data, Nyx stars have abundances that are comparable to both the thick disk (Fig. 2) and dwarf galaxies29–31. However, the small dispersion in the chemical abundances for Nyx does suggest a single progenitor origin, especially given the coherence in velocity space. Given the small subset of Nyx stars with abundances, and the large measurement uncertainties from RAVE-on, further spectroscopic follow-ups (for example, from APOGEE-2, 4MOST and WEAVE) are needed to validate these conclusions."So, why in the other articale they were so sure that those stars came from outside?As they don't come from outside, it is clear that all of those stars had been created in the galaxy itself.Velocity: It is stated that the average speed is 250 Km/sThe Sun is velocity is 220Km/s. So, as both are moving with the galactic disc, how could it be that our scientists claim that they are lagging by 90Km/s with regards to the galactic disc."It is clearly prograde, moving with the Galactic Disk, but lagging in velocity by ~90 km s−1. The 232 most likely stars to belong to Nyx are coherent in velocity, with total average speed 250 km s−1 and dispersion of 48 km s−1."How could it be?Cluster or stellar stream?"In the article it is clearly stated that they specifically claim for a stellar stream as I was expecting:So it isn't a cluster by definition.In any case, as the distance between the stars is about 2KPC (6000Ly) how can we even consider it as a stream?"Here we present evidence for a new prograde stellar stream in the vicinity of the Sun, whose interpretation provides a hint that such a merger occurred in our Galaxy"However, as I have already pointed, our scientists don't know for sure the source of those stars and therefore, they can't claim that it is "a merger occurred in our Galaxy".Conclusion:This article is very confusing. we really don't know the correct locations of the star. We don't know if they are locatedd near a spiral arm or far away from any arm.We don't know the source of those stars Why they claim that they are coming (falling in) from a dwarf galaxy while they claim clearly that "further spectroscopic follow-ups (for example, from APOGEE-2, 4MOST and WEAVE) are needed to validate these conclusions."?How could it be that the stars are moving at 250Km/s and still lagging by 90 km/s?Quote from: Kryptid on 19/08/2020 15:56:27Yes. We can know the direction that a star is moving by look at its redshift. You might want to look it up.Once we understand what do we really see, we can consider if what we see is realistic.
Quote from: Dave Lev on 17/08/2020 15:48:26As I have stated, there are two possibilities for falling in objects:Fall in and collide with the main object or be pushed away.Why don't you consider the third possibility?Don't you understand it?Most people would get to grips with it quite easily.They thing falls towards something, and then misses it.Since you don't seem to understand basic physics, you are not in a position to criticise it, but let's see how you did.Quote from: Dave Lev on 17/08/2020 15:48:26(1) Gravity does not push - Yes It doesIt plainly does not.But you don't understand how something can get close to something and then miss.This says a lot about you...Quote from: Dave Lev on 17/08/2020 15:48:262) Black holes don't break the conservation laws - Black hole does not break the conservation laws and also does not evaporate as Hawking had claimed. There is no negative particles. BH has the ability to create new positive particle pair and give them extra kinetic energy by its high gravity energy.Unless it evaporates in the process of creating new particles, what you have described is a breach of the conservation laws.It's just that you don't seem to be bright enough to recognise this.Quote from: Dave Lev on 17/08/2020 15:48:26(3) Even if they did, it wouldn't help because they wouldn't build a universe that looks like this one - Yes it does. The Rocket over rocket system can do it easily.That wouldn't work anyway,, but it doesn't matter.The "rocket over rocket "idea is a breach of GR.Quote from: Dave Lev on 17/08/2020 15:48:26(4) Even if they could, you still need to explain where the first one comes from - The Universe and its infinite space was always thereNo.Because Olber.Also because the conservation laws.Quote from: Dave Lev on 17/08/2020 15:48:26(5) This simply isn't true "The Black body radiation in the CMB is a clear indication that our Universe is Infinite in its size." - Yes it is. I have already explained this issue. You would never ever get a black body radiation outside the cavity (in the open space). Only if you are located at the cavity itself (or monitor the radiation in the cavity by a tiny hole) you could find the Black body radiation. That's not a sensible explanation.Inside of a finite, large, universe that was once very hot, you expect a CMB.As I have pointed out, what if we are in a big (but finite) box with black walls at 2.7K?That would be finite, and we would see BBR .Quote from: Dave Lev on 17/08/2020 15:48:26(6) Even if it was true, this wouldn't be a valid deduction "Therefore, it also must be infinite in its age." - Yes it is. In order to set an infinite Universe from a single BH you must use infinite time.Other mechanisms (those which are not a pile of junk) do not start from a singe BH and make it grow by magic.Quote from: Dave Lev on 17/08/2020 15:48:26(7) We know that it's finite, thanks to Olber - This is a fiction. Our Universe is infinite. Olber theory could work only if in the all the galaxies in the infinite universe are moving at a velocity which is lower than the speed of light relative to our location.No, because some of them would be moving towards us (very fast).Now, since it's clear that you are wrong about all that, why not just accept that you are wrong?
As I have stated, there are two possibilities for falling in objects:Fall in and collide with the main object or be pushed away.
(1) Gravity does not push - Yes It does
2) Black holes don't break the conservation laws - Black hole does not break the conservation laws and also does not evaporate as Hawking had claimed. There is no negative particles. BH has the ability to create new positive particle pair and give them extra kinetic energy by its high gravity energy.
(3) Even if they did, it wouldn't help because they wouldn't build a universe that looks like this one - Yes it does. The Rocket over rocket system can do it easily.
(4) Even if they could, you still need to explain where the first one comes from - The Universe and its infinite space was always there
(5) This simply isn't true "The Black body radiation in the CMB is a clear indication that our Universe is Infinite in its size." - Yes it is. I have already explained this issue. You would never ever get a black body radiation outside the cavity (in the open space). Only if you are located at the cavity itself (or monitor the radiation in the cavity by a tiny hole) you could find the Black body radiation.
(6) Even if it was true, this wouldn't be a valid deduction "Therefore, it also must be infinite in its age." - Yes it is. In order to set an infinite Universe from a single BH you must use infinite time.
(7) We know that it's finite, thanks to Olber - This is a fiction. Our Universe is infinite. Olber theory could work only if in the all the galaxies in the infinite universe are moving at a velocity which is lower than the speed of light relative to our location.
The Sun is velocity is 220Km/s. So, as both are moving with the galactic disc, how could it be that our scientists claim that they are lagging by 90Km/s with regards to the galactic disc.
"In the article it is clearly stated that they specifically claim for a stellar stream as I was expecting:So it isn't a cluster by definition.In any case, as the distance between the stars is about 2KPC (6000Ly) how can we even consider it as a stream?
Once we understand what do we really see, we can consider if what we see is realistic.
QuoteQuote2.Circular orbit - Let's assume that something had been created. The chance to get an circular orbital system between two objects that came from the deep space in the direction of each other is virtually zero.And yet our moon is such an object, the result of a two-body collision, and having a nearly circular orbit.
Quote2.Circular orbit - Let's assume that something had been created. The chance to get an circular orbital system between two objects that came from the deep space in the direction of each other is virtually zero.
Given a random hit, I'd agree it's not very probable, but you're letting me control things at a distance, which makes it as probable as my ability to measure accurately. One hit is all it takes, not a million.
Phobos is in a circular orbit, which is measurably decreasing every year, so that's another example of an orbit dropping, this time without any interference by a 3rd object.
None of those broken objects would regain the nice round ball shape of a planet or moon.
So, why the Moon orbits around the earth and not around the sun?The answer is quite simple:
The 0.7sec is clearly falling in the error range while the probe is also orbiting Mars.
I totally disagree with the assumption that its radius is decreasing.
If I remember it correctly, our scientists based this assumption on a difference of only 0.7 sec per full orbital cycle while they monitor it from outside by a probe.
The 0.7sec is clearly falling in the error range
QuoteQuote from: Dave Lev on Yesterday at 21:35:43If I remember it correctly, our scientists based this assumption on a difference of only 0.7 sec per full orbital cycle while they monitor it from outside by a probe.No, it was measured from the surface. A lander there was able to measure (not assume, not theorize, not simulate, but actually measure) that the time it takes for Phobos to orbit Mars is slowly decreasing. So this means it's either speeding up, coming closer to Mars, or both.
Quote from: Dave Lev on Yesterday at 21:35:43If I remember it correctly, our scientists based this assumption on a difference of only 0.7 sec per full orbital cycle while they monitor it from outside by a probe.
Would you kindly introduce this interesting article about Phobos.
The Mars Orbiter Laser Altimeter (MOLA) instrument on the Mars Global Surveyor spacecraft has observed 15 transits of the shadow of Phobos across the surface of Mars, and has directly measured the range to Phobos on one occasion. The observed positions of Phobos and its shadow are in good agreement with predictions from orbital motion models derived from observations made prior to 1990, with the notable exception that Phobos is gradually getting ahead of its predicted location. This effect makes the shadow appear at a given location earlier than predicted, and the discrepancy is growing by an amount which averages 0.8 s/yr.
The instrument time is related to the spacecraft clock with submillisecond precision [Neumann et al., 2001], and spacecraft time is maintained by the Mars Global Surveyor project with accuracy better than 30 milliseconds relative to UTC.
After looking into it further, it seems that it was indeed measured by a spacecraft as you said. That was a mistake on my part. One article describing the measurement is here: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2004JE002376
The Mars Orbiter Laser Altimeter (MOLA) instrument on the Mars Global Surveyor spacecraft has observed 15 transits of the shadow of Phobos across the surface of Mars,
As stated above, the overall accuracy of the laser altimeter is in the range of +30 milliseconds (+0.03 seconds). That uncertainty is significantly smaller than the measured value of 0.8 seconds per year, so you can't blame the measured decrease in orbital time of Phobos on uncertainty.