[Professor Mega-Mind (OP)]

   Do Red-Dwarfs eat giant rocks ?
 Do red-dwarf stars tend to draw in , and ingest , their close-in rocky planets ?  The answer, surprisingly, should be yes!  The mechanisms for such a draw-down appear to be both tidal-gravitational , and magnetic in nature . They mainly affect the closer in bodies , but since they are all tidally conjoined and synchronized , lowering one orbit lowers them all (slowly) . It is stellar rotation that does the job.  If is fast (Trappist1) then the stellar influence upholds the inner planet's orbits , while allowing further out planets to descend into resonant orbits with them .  If the stellar rotation is slow (Proxima , Ross 128) , then the magnetic and tidal drag spirals the close-in planets into the red-dwarf , leaving only further out rocky worlds . *It is suggested here that a standard be established for the likelihood of planets around red-dwarf stars. Such should include stellar mass , rotation period , and age , as well as lithium presence . 
 P.M.
.  Addendum-Modelling indicates that ALL stars slow their spin over time .  The above forces have greater effect upon more massive & luminous stars ; slowing them preferentially. Less appreciated , however , is the effect of photon-momentum transfer upon these stars .  The approaching side of the star emits higher-energy photons , than the receding side .  Over time , the greater recoil engendered by this , acts to slow the star's rotation .  Heavier , and much brighter stars , will be slowed much more quickly than dimmer stars , by this effect .  Once adequately slowed , these stars will begin to tidally slow their planet's revolutions , thus drawing them in , and eventually ingesting them .
》For relevant analysis , read NSF thread: How do protoplanets form?
www.thenakedscientists.com/forum/index.php?topic=74806.new;topicseen#new   
 

[Dave Lev]

     Do Red-Dwarfs eat Rock.s ?
 Do red-dwarf stars tend to draw in , and ingest , their close-in rocky planets ? The answer , surprisingly , appears to be yes !  The mechanisms for such a draw-down appear to be both tidal- gravitational ,and magnetic in nature . They mainly affect the closer in bodies , but since they are all tidally conjoined and synchronized , lowering one orbit lowers them all ( slowly ).  It is stellar rotation that does the job.  If is fast ( Trappist1 ) then the stellar influence upholds the inner planet's orbits , while allowing further out planets to descend into resonant orbits with them .  If the stellar rotation is slow ( Proxima , Ross 128 ) , then the magnetic and tidal drag spirals the close-in planets into the red-dwarf , leaving only further out rocky worlds . 
 It is suggested here that a standard be established for the likelihood of planets around red-dwarf stars. Such should include stellar mass , rotation period , and age , as well as lithium presence . 
OK , dwarf stars get hungry ! P.M.

What is the source for that idea?
Do you have any evidence to support it?
Why only red-dwarf stars and not Sun like stars?
How tidal- gravitational and magnetic effect the orbital path?
Why lowering one orbit lowers them all?
Based on the current evidences, the Earth is drifting away from the Sun, while the moon is also drifting away from Earth.
So, there is good chance that all planets and moons (not asteroids or broken moons) are actually drifting away from their host center.

[Professor Mega-Mind (OP)]

            To : Inquisitive Dave
The evidence gives rise to the idea.
I contrast red-dwarfs with yellow dwarfs because , as you realized , yellow dwarfs lift their satellites to higher orbit ( Earth ~1Mkm. , while red-dwarfs draw theirs in .  The nearest examples of this effect are Luna ( rising tidal ) , and Phobos 
( lowering tidal ) .  These are not members of orbital-resonance chains , but if they were they would fight to stay in resonance .Examine Trappist1 b & c .  Both are part of a resonant chain , both revolve around their parent body faster than it's rotation rate .  Tidal force should drag them down towards their star, and out of orbital resonance . It tries , but cannot .  Both hold at 60 percent orbital radius , instead of the 2/3 that nature prefers ( nature prefers the simpler ratio ) .  The resonant chain experiences rising tidal force on all of the planets except these two .  The rising and sinking forces balance , and the system maintains for billions of years .  The cost of this is stellar rotational energy turned into tidally induced internal heat in the planets involved .
Okay !  Hope you learned some tidal dynamics here !  Enjoy ,  P.M. 
Note - To put it simply ; if the central-body rotates faster than the satellite revolves around it , then it lifts the satellite into a higher orbit .  If the central-body rotates slower than the satellite , then it drags it into a lower orbit .  Resonant-chains fight these effects , converting rotational energy into tidal-friction heat in the process .

[Dave Lev]

The nearest examples of this effect are Luna ( rising tidal ) , and Phobos ( lowering tidal ) .

Phobos is a broken moon as it is irregularly shaped object.
There is a possibility for asteroids and broken/ irregularly objects to drift inwards.
However, you won't find even one none broken moon or planet that are drifting inwards.
Hence, the idea of "lowering tidal" is none realistic.

[Professor Mega-Mind (OP)]

           To : Skeptic Dave Lev
 Try Neptune's moon Triton .  At 1700 miles diameter it is not broken .  It travels well ahead of it's tidal bulge , and and in 3.6 billion years will reach the Roche limit , and break up . 
As the Pred. said in Predator 1 .
" Sh_t happens ! ".
P.M. 
Note - Triton is not a real a Neptunian moon .  It appears to be a captured Plutonian dwarf-planet .  The dearth of large NeptunIan moons is likely due to orbital disruption by Triton , long ago .

[Dave Lev]

Try Neptune's moon Triton .  At 1700 miles diameter it not broken .

Triton is also irregularly shaped object.
https://en.wikipedia.org/wiki/Triton_(moon)#/media/File:Triton_moon_mosaic_Voyager_2_(large).jpg
Hence, by definition it is a broken moon.
Please try to find none broken object.

[Kryptid]

I contrast red-dwarfs with yellow dwarfs because , as you realized , yellow dwarfs lift their satellites to higher orbit ( Earth ~1Mkm. , while red-dwarfs draw theirs in .  The nearest examples of this effect are Luna ( rising tidal ) , and Phobos 

The reason that our Moon rises away from the Earth whereas Phobos falls towards Mars is due to the transfer of tidal energy. The Earth spins faster than the Moon orbits around it, so the Moon can gain energy through tidal interactions with the Earth. In the process, the Earth's rotation slows down. The opposite is true of Phobos because it orbits Mars faster than Mars rotates. Neptune's satellite Triton orbits the planet in the opposite direction of its spin, which means that tidal forces slow down both Triton's orbit (drawing it in closer) and slow Neptune's rotational speed as well.

[Dave Lev]

I contrast red-dwarfs with yellow dwarfs because , as you realized , yellow dwarfs lift their satellites to higher orbit ( Earth ~1Mkm. , while red-dwarfs draw theirs in .  The nearest examples of this effect are Luna ( rising tidal ) , and Phobos 

The reason that our Moon rises away from the Earth whereas Phobos falls towards Mars is due to the transfer of tidal energy. The Earth spins faster than the Moon orbits around it, so the Moon can gain energy through tidal interactions with the Earth. In the process, the Earth's rotation slows down. The opposite is true of Phobos because it orbits Mars faster than Mars rotates. Neptune's satellite Triton orbits the planet in the opposite direction of its spin, which means that tidal forces slow down both Triton's orbit (drawing it in closer) and slow Neptune's rotational speed as well.

Let's try to focus on evidences (For real Moons and Planets).
1.Rise away:
Do you agree that all planets in the solar system rise away from the Sun while all real moons rise away from their host planets?
2. Rotational speed
Do you agree that all planets and moons in the solar system slow down their rotational speed over time?

It seems to me that objects can't keep their current orbital radius forever. They must rise away or draw in closer over time.
Kepler formula is Ok for very limited time frame.
However, the time effect is missing in that formula.
Do you agree that due to this time effect, all real moons and planet must rise away?
If that is correct, then "Tidal" might not be the correct answer for our discussion.

[Professor Mega-Mind (OP)]

 To : Dave Lev
 I actually must disagree with both.  Planets & moons may increase or decrease their orbital radius IF kinetic energy is added/subtracted to their revolution about their main body .  The same principle applies to satellite/central-body rotation .  I trump your Kepler w/my Newton .  Energy can't be created/destroyed , but it sure can be transferred ! 
 A yellow-dwarf planet can surely migrate inwards , and a red-dwarf planet absolutely can migrate out .  Both rotation & revolution can last forever , in theory , but in reality ; friction & other energy transfers modify these characteristics severely over time .
Alrighty then !  Didn't use " Tidal " , did use " Time " ! 
U must be one happy Homer !..P.M.
*Note : Triton appears to be a captured Kuiper-belt object ; a dwarf-planet very similar to the former planet Pluto .

[Dave Lev]

Both rotation & revolution can last forever , in theory , but in reality ; friction & other energy transfers modify these characteristics severely over time .

Yes, I fully agree with this statement.
Therefore, it is expected that over time as orbital object rises away, its orbital velocity decreases.

A yellow-dwarf planet can surely migrate inwards..

Would you kindly offer an example for that assumption.

[Kryptid]

Let's try to focus on evidences (For real Moons and Planets).
1.Rise away:
Do you agree that all planets in the solar system rise away from the Sun while all real moons rise away from their host planets?

No, I don't. As has already been pointed out, Triton and Phobos are both slowly spiraling in towards their host planets. They are "real" moons and I don't know what dictionary definition of "moon" you would be using to disqualify them as such.

2. Rotational speed
Do you agree that all planets and moons in the solar system slow down their rotational speed over time?

Without any external forces at work, yes, they would. However, tidal forces have the potential to speed them up under the right circumstances. Such should be happening with the Mars-Phobos system right now.

It seems to me that objects can't keep their current orbital radius forever. They must rise away or draw in closer over time.
Kepler formula is Ok for very limited time frame.
However, the time effect is missing in that formula.

Correct. Orbits change over long periods.

Do you agree that due to this time effect, all real moons and planet must rise away?

No. They can only rise away if there is some source of energy they can exploit that allows them to enter a higher state of potential energy (i.e. a higher orbit). Tidal forces are one such source, although solar wind and radiation pressure might also contribute a very small amount.

If that is correct, then "Tidal" might not be the correct answer for our discussion.

Tidal effects are not the only thing that affects orbits. Gravitational radiation causes planets and satellites to lose energy over time and for their orbits to decay. The Moon is rising away from us at the moment, but will eventually stop and begin moving back in once gravitational radiation becomes the dominant force at work (barring that the Sun is likely to destroy the Earth and Moon long before that happens, of course). However, orbital decay due to gravitational radiation it is an extremely slow process that is easily overwhelmed in the short term by other factors on the scale of mere planets.

[evan_au]

It seems that this thread is focusing on very small effects over long periods of time.
- Tidal effects decrease as something like the third power of distance (inverse cube law)
- The effects of tide on the Earth-Moon distance is (just) measurable, because of the retroreflectors left on the Moon by astronauts
- The effects of tide on the Earth-Sun system would be slightly smaller than tides in the Earth-Moon system
- But 4cm in 400,000km (Earth-Moon distance) is much more significant than 4cm in 150,000,000km (Earth-Sun distance)!
- As you say, this would have a greater effect on planets orbiting very close to their parent star.

There are some more dramatic events that change the orbits of planets on short and medium timescales, especially in young planetary systems.
- In these systems, not all objects have settled into roughly circular orbits, traveling in the same direction
- Major collisions are expected, like the craters seen on the Moon, and the formation of the Moon itself
- But more subtly, any orbital resonances cause orbital irregularities to grow over periods of thousands to millions of years, causing increasing resonance interactions
- This can cause planets to swap orbits
- In extreme interactions, this can cause the smaller planet to gain enough angular momentum to be flung out of the system, or lose so much angular momentum that it is dropped into the star
- Gravitational interactions follow an inverse square law, and happens on much smaller timescales than tidal effects (inverse cube law).

[Kryptid]

If a planet was 25,500,000 kilometers from the Sun, it would complete an orbit about as quickly as the Sun's equator rotates. Closer than that, and the planet orbits faster than the Sun's rotation. Under such circumstances, you'd expect tidal forces to draw the planet in towards the Sun instead of pushing it outward (very, very slowly, as evan_au points out). Once the planet passes within the Sun's roche limit (around 500,000 to 2,000,000 kilometers, depending on the physical nature of the planet itself), it would break up.

[Professor Mega-Mind (OP)]

                  Special note
It appears that all proto-stars and Jovians form with very high rates of rotation .  Both magnetic & tidal forces then begin to slow this rotation , but at widely differing rates and times . The heavier stars have more angular momentum , yet proportionally less mass close in to transfer it to .  Consequently , they tend to spin down less , while the less massive stars spin down more . The obvious exceptions are ultra-cool red-dwarfs, brown-dwarf stars , and Jovian planets .  These lack the powerful , long-term , magnetic interactions of the heavier gas-bodies , thus they experience far less total spin-down over time . 
The clinching evidence for this effect is the relative dearth of close-in planets around slower-spinning stellar bodies .  This will presumably include slow-spinning Jovian-body systems , once we can find & observe them in detail .
 "Hokay" Nuff said !.....P.M.

[Kryptid]

The clinching evidence for this effect is the relative dearth of close-in planets around slower-spinning stellar bodies . 

Can you run those numbers by us, please?

[Professor Mega-Mind (OP)]

If you are questing for planets within 5 million miles of their  parent bodies , you will find a paucity of these around yellow-dwarf stars , let alone white/blue stars .  There are a few kamikaze planets spiraling in though .  Most of the planets you can identify as closer than 5M.mi. are around red-dwarf stars .  Our own stellar system exemplifies this : Jovian-body 4 , Yellow-dwarf 0 .
Keep in mind that the Jovian satellites could have formed even closer in , then been raised , as a resonant chain , by Jupiter's  tidal forces acting primarily upon Io .  Saturn's moon Titan could have been raised in a manner similar to our Moon .
Last interest : Trappist1 b&c must have volcanism well in excess of that of Io .  The forces , masses , & radiogenic heating involved should be far in excess of those affecting Io , the final hell-factor would be the ultra-hot , hyper-venusian atmospheres of these two worlds .
OK , Trappist1 is hot as snot !..P.M.

[evan_au]

If you are questing for planets within 5 million miles of their  parent bodies , you will find a paucity of these around yellow-dwarf stars , let alone white/blue stars

In general, I expect that a small star would form from a small protoplanetary disk...
...and a large star from a larger protoplanetary disk.

A small protoplanetary disk would have planets close in to their red dwarf star...
... while a large protoplanetary disk would have planets forming far from their blue/white star.

[Professor Mega-Mind (OP)]

10-4 good buddy !  A yellow-dwarf would have to slow waaay down to ingest even a Mercury .  An Earth would be absurd !  Even then it would take hundreds  of billions of  years ! Yellow star bloats up, melts planet first ! 
It's usually high-mass red-dwarfs that fit this bill !........P.M.
---------------------------------------------
》Addendum - 9/7/20 .
 It now appears that red-dwarf stars are actually more amenable to rocky-planet formation than yellow-dwarf stars . This likely is because yellow-dwarfs heat their protostellar disks to higher temperatures than red dwarfs . This would greatly facilitate stellar-wind blow-out of gas/dust from an inner stellar-system . Add orbital-forces pushing planetoids into resonant orbits , and you wind up with sparsely populated inner stellar-systems for yellow-dwarf stars . Red-dwarfs however , can wind up more crowded than Jupiter , if their stellar rotation-rates are faster than their planetary revolution-rates .
.

[Dave Lev]

Let's try to focus on evidences (For real Moons and Planets).
1.Rise away:
Do you agree that all planets in the solar system rise away from the Sun while all real moons rise away from their host planets?

No, I don't. As has already been pointed out, Triton and Phobos are both slowly spiraling in towards their host planets. They are "real" moons and I don't know what dictionary definition of "moon" you would be using to disqualify them as such.

It is stated clearly and we can also see that Triton and Phobos are irregular objects.
Any moon or planet which has an irregular shape, must be considered as a broken object.
This broken object could be an indication that in the past it had been collide with other object.
The impact due to collision could set it into orbital decay. But this inwards direction is not due to gravitational radiation.
So, in this discussion we only focus on moons and planets with regular shape (None broken objects - I call them REAL moons and planets.)
Therefore, do you agree that as Triton and Phobos do not have a regular shape, they can't give any indication for any other none broken object (Noon or planet)?

2. Rotational speed
Do you agree that all planets and moons in the solar system slow down their rotational speed over time?

Without any external forces at work, yes, they would. However, tidal forces have the potential to speed them up under the right circumstances. Such should be happening with the Mars-Phobos system right now.

Currently, we have only tested two none broken objects. Earth and Moon.
We have found that both of them are rising outwards.
We also assume that all the other planets in the solar system are rising outwards.
So, do you agree that from statistical point of view, 100% of the tested none broken objects are rising outwards?
If that is correct, than it is solid evidence that any none broken objects (Moon, planet and even stars) must rise outwards.
If we want to believe that due to tidal or any other idea, none broken object can rise inwards - we must offer a real evidence for that.
Without it, do you agree that the idea of drifting inwards for none broken objects is only a speculation?

It seems to me that objects can't keep their current orbital radius forever. They must rise away or draw in closer over time.
Kepler formula is Ok for very limited time frame.
However, the time effect is missing in that formula.

Correct. Orbits change over long periods.

Thanks

Do you agree that due to this time effect, all real moons and planet must rise away?

No. They can only rise away if there is some source of energy they can exploit that allows them to enter a higher state of potential energy (i.e. a higher orbit). Tidal forces are one such source, although solar wind and radiation pressure might also contribute a very small amount.

You are using nice words as: Tidal, Solar wind, Radiation pressure... but so far we didn't find even one real evidence to support this hypothesis.

If that is correct, then "Tidal" might not be the correct answer for our discussion.

Tidal effects are not the only thing that affects orbits. Gravitational radiation causes planets and satellites to lose energy over time and for their orbits to decay. The Moon is rising away from us at the moment, but will eventually stop and begin moving back in once gravitational radiation becomes the dominant force at work (barring that the Sun is likely to destroy the Earth and Moon long before that happens, of course). However, orbital decay due to gravitational radiation it is an extremely slow process that is easily overwhelmed in the short term by other factors on the scale of mere planets.

Why do we believe that the Moon will eventually stop and begin moving back?
Do you agree that it is a pure speculation?
Can we offer even one evidence for that (based on none broken moon)?

[Kryptid]

It is stated clearly and we can also see that Triton and Phobos are irregular objects.
Any moon or planet which has an irregular shape, must be considered as a broken object.
This broken object could be an indication that in the past it had been collide with other object.
The impact due to collision could set into orbital decay. But this inwards direction is not due to gravitational radiation.
So, in this discussion we only focus on moons and planets with regular shape (None broken objects - I call them REAL moons and planets.)
Therefore, do you agree that as Triton and Phobos do not have a regular shape, they can't give any indication for any other none broken object (Noon or planet)?

I don't agree that Triton is a "broken object". It looks quite spherical to me. It's the 7th largest moon in the Solar System. Your definition of a "real" moon has not been substantiated by a dictionary or a scientific source.

Currently, we have only tested two none broken objects. Earth and Moon.
We have found that both of them are rising outwards.
We also assume that all the other planets in the solar system are rising outwards.
So, do you agree that from statistical point of view, 100% of the tested none broken objects are drifting outwards?

No. Triton is not "broken".

If that is correct, than it is solid evidence that any none broken objects (Moon, planet and even stars) must rise outwards.

Not without a mechanism to give them energy to rise against a gravitational potential.

If we want to believe that due to tidal or any other idea, none broken object can rise inwards - we must offer a real evidence for that.

The laws of physics demand it. Things don't spontaneously rise away from a gravitational source without some source of energy. That would violate conservation of energy.

Without it, do you agree that the idea of rising inwards for none broken objects is only a speculation?

Absolutely not. Triton is not a "broken" object.

You are using nice words as: Tidal, Solar wind, Radiation pressure... but so far we didn't find even one real evidence to support this hypothesis.

The laws of physics are the evidence. Things don't spontaneously fall "up".

Why do we believe that the Moon will eventually stop and begin moving back?
Do you agree that it is a pure speculation?
Can we offer even one evidence for that (based on none broken moon)?

When the Earth and Moon become tidally-locked, there will be no more rotational energy left for the Earth to donate to the Moon's orbit. Without any more energy coming in, the Moon has to stop. Energy doesn't come out of nowhere.