Are all masses like black holes?

  • 112 Replies
  • 3145 Views
Re: Are all masses like black holes?
« Reply #90 on: February 19, 2018, 09:27:14 PM »
Quote
I did ask E E K, "Would you now calculate how long it would take a hammer of mass 1 kg and a feather of mass 0.05 g to fall 10 m in a perfect vacuum?"

Earth and hammer will strike first if aforementioned both hammer and feather dropped at the same time from the same altitude but on antipodes - It's all about the concept of idea, not calculation

EDIT: However, all objects may free fall at the same rate regardless of their mass if it is the natural tendency of smaller objects to drive towards a massive object in the region.
« Last Edit: February 19, 2018, 10:15:10 PM by E E K »

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #91 on: February 19, 2018, 10:06:27 PM »
Quote
I did ask E E K, "Would you now calculate how long it would take a hammer of mass 1 kg and a feather of mass 0.05 g to fall 10 m in a perfect vacuum?"

Earth and hammer will strike first if aforementioned both hammer and feather drop at the same time from the same altitude but on antipodes - It's all about the concept, not calculation
But the difference is so small that there not the slightest chance of even
  • getting a vacuum on earth of sufficient quality to perform a valid experiment and
  • measuring to sufficient precision to be meaningful - the difference would be something like 1 part in 6 × 1024.
No scientific theories would ever be claimed valid to that precision.
An error in altitude by the diameter of a proton would cause about 1000 times as much error, so you stick your concepts and I'll worry about things that matter.

If, instead of earth, your were talking about a metre diameter sphere of rock, a one kilogram hammer and a feather isolated in space, it might be a different matter.

Re: Are all masses like black holes?
« Reply #92 on: February 19, 2018, 10:17:22 PM »
As said in above Edit:

All objects may free fall at the same rate regardless of their mass if it is the natural tendency of smaller objects to drive towards a massive object in the region.

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #93 on: February 19, 2018, 10:53:41 PM »
As said in above Edit:

All objects may free fall at the same rate regardless of their mass if it is the natural tendency of smaller objects to drive towards a massive object in the region.
There is no "natural tendency"
It's simply a result of gravitation applying the same force (though in opposite directions) to each object, so that the amount they move is inversely proportional to their mass.

What you have been saying about the earth, hammer and feather was"correct in principle", but the difference im masses is so massive that for all intents and purposes the earth does not move.

The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Quote from: Wikipedia
Barycenter
Rather than appearing to orbit a common center of mass with the smaller body, the larger will simply be seen to wobble slightly. This is the case for the Earth–Moon system, where the barycenter is located on average 4,671 km (2,902 mi) from the Earth's center, well within the planet's radius of 6,378 km (3,963 mi).

Two bodies with a major difference
in mass orbiting a common
barycenter internal to one body
(similar to the Earth–Moon system)
distances not to scale



Re: Are all masses like black holes?
« Reply #94 on: February 19, 2018, 11:10:36 PM »
Quote
The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Freedom of choice - Choose what is right for You
« Last Edit: February 19, 2018, 11:12:47 PM by E E K »

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #95 on: February 19, 2018, 11:27:40 PM »
Quote
The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Freedom of choice - Choose what is right for You
But that doesn't make your choice correct, though in this Trump era, with it's fake-fax and alternate-fax, who knows?

*

Macarios

  • 1190
Re: Are all masses like black holes?
« Reply #96 on: February 20, 2018, 12:14:42 AM »
If feather and hammer fall together, they hit Earth together, because they have combined pull and Earth intercepts them together.
If they fall in succession, one and then another, hammer would in deed fall a tiny bit faster, but that tiny bit is many times tinier than our measuring abilities.
Mathematically it can be shown, but there is no way (not even slightest chance) to measure such small difference in reality.

Wrong
That's like saying someone with an open parachute and someone without a parachute will land at the same time.

Aerodynamics and the much lighter weight of the feather could result in the feather being picked up by the wind and not landing somewhere else a long time after.

Thanks, but EEK was talking of hypothetical situation without air or other object in vicinity.

The example with hammer and feather was about free fall in vacuum.
That was what Apollo astronaut did on the Moon.
Same as feather and bowling ball in that giant vacuum chamber.

We all know that in air there is air drag.
I don't have to fight about anything.
These things are not about me.
When one points facts out, they speak for themselves.
The main goal in all that is simplicity.

Re: Are all masses like black holes?
« Reply #97 on: February 20, 2018, 12:34:38 PM »
Quote
The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Gravitational force between sun and moon; F1 = GMm/d^2; where M = mass of sun R = radius of sun and m= mass of moon

Gravitational force between earth and moon; F2 = GMm/d^2; where M = mass of earth R = radius of earth, and m = mass of moon

Since F1 > F2 after calculation therefore shouldn’t moon revolve the sun in its separate orbit?

Gravitational force between earth and sun; F = GMm/d^2; where M = mass of sun, R = radius of sun and m= mass of earth

Gravitational acceleration of sun; gs = GM/R^2 ;
Earth revolves in its orbit due to gs = GM/R^2,

Doesn’t earth change its acceleration (in reference to the gs=GM/d^2 of sun) due to the barycenter of earth and moon in its orbit around the sun?

Re: Are all masses like black holes?
« Reply #98 on: February 20, 2018, 12:41:19 PM »
Quote
That was what Apollo astronaut did on the Moon.
It might be true if they really went to the moon but the mass or the gravity of the moon is still unknown according to the mainstream science.  Had you missed one of my posts? Here

https://www.theflatearthsociety.org/forum/index.php?topic=74238.0
« Last Edit: February 20, 2018, 12:44:36 PM by E E K »

*

Macarios

  • 1190
Re: Are all masses like black holes?
« Reply #99 on: February 20, 2018, 01:26:34 PM »
Quote
The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Gravitational force between sun and moon; F1 = GMm/d^2; where M = mass of sun R = radius of sun and m= mass of moon

Gravitational force between earth and moon; F2 = GMm/d^2; where M = mass of earth R = radius of earth, and m = mass of moon

Since F1 > F2 after calculation therefore shouldn’t moon revolve the sun in its separate orbit?

Gravitational force between earth and sun; F = GMm/d^2; where M = mass of sun, R = radius of sun and m= mass of earth

Gravitational acceleration of sun; gs = GM/R^2 ;
Earth revolves in its orbit due to gs = GM/R^2,

Doesn’t earth change its acceleration (in reference to the gs=GM/d^2 of sun) due to the barycenter of earth and moon in its orbit around the sun?

You are using the same letter "d" for distance in all formulas.
I hope you haven't forgot that distance between Sun and Moon is much greater than distance between Earth and Moon.

And what orbits the Sun is actually the barycenter that Earth and Moon revolve together.
Distance between center of Earth and barycenter is just 27 ppm of the distance between Earth and Sun.
It is 0.0027 percent, so if you disregard it you are still pretty accurate.
I don't have to fight about anything.
These things are not about me.
When one points facts out, they speak for themselves.
The main goal in all that is simplicity.

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #100 on: February 20, 2018, 01:36:46 PM »
Quote
That was what Apollo astronaut did on the Moon.
It might be true if they really went to the moon but the mass or the gravity of the moon is still unknown according to the mainstream science.  Had you missed one of my posts? Here

https://www.theflatearthsociety.org/forum/index.php?topic=74238.0
Incorrect. The mass and gravity of the moon were calculated approximately long ago from the tidal effect on earth and from the position of the earth-moon barycentre.

Then, once spacecraft were sent to the vicinity of the moon, the mass and gravity could be calculated very accurately.
Quote from: Wikipedia
The Soviet Union sent the first spacecraft to the vicinity of the Moon, the robotic vehicle Luna 1, on January 4, 1959. It passed within 6,000 kilometres (3,200 nmi; 3,700 mi) of the Moon's surface, but did not achieve lunar orbit. Luna 3, launched on October 4, 1959, was the first robotic spacecraft to complete a circumlunar free return trajectory, still not a lunar orbit, but a figure-8 trajectory which swung around the far side of the Moon and returned to the Earth. This craft provided the first pictures of the far side of the Lunar surface.

The Soviet Luna 10 became the first spacecraft to actually orbit the Moon in April 1966. It studied micrometeoroid flux, and lunar environment until May 30, 1966.

The first United States spacecraft to orbit the Moon was Lunar Orbiter 1 on August 14, 1966. The first orbit was an elliptical orbit, with an apolune of 1,008 nautical miles (1,867 km; 1,160 mi) and a perilune of 102.1 nautical miles (189.1 km; 117.5 mi).[5] Then the orbit was circularized at around 170 nautical miles (310 km; 200 mi) to obtain suitable imagery. Five such spacecraft were launched over a period of thirteen months, all of which successfully mapped the Moon, primarily for the purpose of finding suitable Apollo program landing sites.

Re: Are all masses like black holes?
« Reply #101 on: February 20, 2018, 04:15:28 PM »
Quote
You are using the same letter "d" for distance in all formulas.
- I presumed you all know that at this stage.

1 ppm or 27 ppm but doesn't it change the "g" of the sun which causes the orbital motion of the earth as F = GMm/d^2 where M = mass of sun, m = mass of earth and d=o/c center between earth and sun. Even if it is disregarded then what is the speed of this barycenter (combined effect of earth and moon) which orbits the sun and how would you apply the universal law of gravitation to it and sun?

Re: Are all masses like black holes?
« Reply #102 on: February 20, 2018, 04:23:17 PM »
Quote
incorrect. The mass and gravity of the moon were calculated approximately long ago from the tidal effect on earth and from the position of the earth-moon barycentre.

Your claim is unbeknownst to me but none of the celestial bodies mass or gravity is known as per aforesaid link.

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #103 on: February 20, 2018, 08:51:08 PM »
Quote
incorrect. The mass and gravity of the moon were calculated approximately long ago from the tidal effect on earth and from the position of the earth-moon barycentre.

Your claim is unbeknownst to me but none of the celestial bodies mass or gravity is known as per aforesaid link.
According to what link, this one, Does "g =GM/d^2" best in situ in mathematical equation of "F = GMm/d^2 = mg"??
I see nothing there that shows that "none of the celestial bodies mass or gravity is known".

If not that link, which do you mean?

It is comparitively easy to calculate the mass of any body with one or more orbiting satellites
If the size of the body is known, its mass can also by calculated if an object can be observed falling into it.
Both of these methods were used to determine the mass of the moon even before any unmanned craft soft landed on the moon..

Re: Are all masses like black holes?
« Reply #104 on: February 20, 2018, 09:13:04 PM »
Quote
It is comparitively easy to calculate the mass of any body with one or more orbiting satellites
If the size of the body is known, its mass can also by calculated if an object can be observed falling into it.
Both of these methods were used to determine the mass of the moon even before any unmanned craft soft landed on the moon..
How or Any reference

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #105 on: February 20, 2018, 09:35:39 PM »
Quote
It is comparitively easy to calculate the mass of any body with one or more orbiting satellites
If the size of the body is known, its mass can also by calculated if an object can be observed falling into it.
Both of these methods were used to determine the mass of the moon even before any unmanned craft soft landed on the moon..
How or Any reference
Easy, peasy: How do scientists measure or calculate the weight of a planet?
Or: Ask an Astronomer, How do you measure a planet's mass? (Beginner)

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #106 on: February 20, 2018, 10:38:52 PM »
Quote
The moon is big enough to have a significant and the earth-moon system orbits a common centre, the barycentre,
Gravitational force between sun and moon; F1 = GMm/d^2; where M = mass of sun R = radius of sun and m= mass of moon
Gravitational force between earth and moon; F2 = GMm/d^2; where M = mass of earth R = radius of earth, and m = mass of moon

Since F1 > F2 after calculation therefore shouldn’t moon revolve the sun in its separate orbit?
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I'll edit your equations to make it easier for me to follow. I hope it keeps your intent:
Gravitational force between sun and moon: Fsm = GMsunmm/Rsm2; where Msun = mass of sun, Rsm = radius of moon's orbit about sun and mm = mass of moon

Gravitational force between earth and moon: Fem = Gmemm/Rem2; where me = mass of earth, Rem = radius of moon's orbit about earth, and mm = mass of moon

Since Fsm > Fem after calculation therefore shouldn’t moon revolve the sun in its separate orbit?

This bit is a very good question and is more than enough for one answer.

Part of the answer is that, as you say, the sun's gravitational field (gravity) near earth is greater than the gravitation field of the earth at the moon.
The sun's gravitational field (gravity) near the earth, however, changes only slightly over the radius of the moon's orbit around the earth.
In other words, the whole earth-moon system is attracted by the sun by almost the same amount, so the moon orbits the earth.
But, the earth-moon system travels around the sun at a much higher tangential velocity than the moon's velocity around the earth.

So the motion is an orbit around the sun at the same radius as the earth with just a little wriggle, with a period on one month, to make it orbit the earth.
This diagram, to scale, shows just half a month.

This just shows half a month. If I wanted to show a longer
time period, the motion of the Earth and moon around the
Sun would make it super-difficult to see the motion of the
moon relative to the Earth.
Read in detail in: WIRED, Does the Moon Orbit the Sun or the Earth?

There are many more references on this, as at first it seems a little puzzling.
Physics Stack Exchange, Why does the moon not revolve around the sun directly?
Then one that brings in Gravity Wells, EXPLAIN xkcd, Gravity Wells.
And there are plenty more. Just search for "Why does moon orbit the earth and not the sun?".

Re: Are all masses like black holes?
« Reply #107 on: February 21, 2018, 07:52:41 PM »
Quote
easy peasy
The only way we can measure a planet's mass is through its gravity as per your link  - This needs a gravity model free of mathematical errors.

Quote
Since Fsm > Fem after calculation therefore shouldn’t moon revolve the sun in its separate orbit?

There are 4 possibilities in the current model - impov

1- When the earth is in between the sun and moon: Shouldn't the combined effect of earth and sun alter the orbit of the moon and its speed as well

2- when the moon is in between earth and sun: Either Moon should fall to the sun instead of earth or at least there should be a reduction in its speed and the change in its orbit around the earth

3- Moon should revolve the sun in its separate orbit instead of orbiting the earth

4- The current orbit of the earth around the sun doesn't fit for both earth and moon if there is a combined effect of binary plates (earth and moon) on sun
« Last Edit: February 21, 2018, 08:06:36 PM by E E K »

Re: Are all masses like black holes?
« Reply #108 on: February 21, 2018, 08:15:10 PM »
Quote
easy peasy
The only way we can measure a planet's mass is through its gravity as per your link  - This needs a gravity model free of mathematical errors.

Errors limit the precision we're capable of obtaining, but if the errors (or unknowns) are reasonably small, the precision can be reasonably high.

Quote
Quote
Since Fsm > Fem after calculation therefore shouldn’t moon revolve the sun in its separate orbit?

The moon is actually orbiting the sun. Its orbit is significantly perturbed by the earth, however. From the point of view of the earth, the moon appears to revolve around it. From the POV of the sun, earth and moon appear to alternately overtake each other, slightly speed up, slow down, get nearer and farther away, and follow a braided path, while the barycenter (center of mass) of the earth-moon system follows a smooth orbit.

Quote
There are 4 possible case according to current model - impov

1- When the earth is in between the sun and moon: Shouldn't the combined effect of earth and sun alter the orbit of the moon and its speed as well

2- when the moon is in between earth and sun: Either Moon should fall to the sun instead of earth or at least there should be a reduction in its speed and the change in its orbit around the earth

3- Moon should revolve the sun in its separate orbit instead of orbiting the earth

4- The current orbit of the earth around the sun doesn't fit for both earth and moon if there is a combined effect of binary plates (earth and moon) on sun

This is a three-body problem. Keplerian orbits only apply to two bodies, not more. Solving three-body problems (or, more generally, N-body problems for N > 2) is not trivial; it can only be done numerically, but it can be done (for N < some fairly large number).
"Everyone is entitled to his own opinion, but not to his own facts." - Daniel Patrick Moynihan

Re: Are all masses like black holes?
« Reply #109 on: February 21, 2018, 08:45:34 PM »
Quote
Errors limit the precision we're capable of obtaining, but if the errors (or unknowns) are reasonably small, the precision can be reasonably high.

All objects free fall at the same rate regardless of their mass - we don't notice because objects are very small as compared to earth

Is it possible for an imaginary earth to free fall at the same rate?

The "g" of the imaginary earth is equal to the "g" real earth but in opposite direction - so guess?

if not then how is it possible to calculate the "Mass of the Earth" in the following link?

http://www.citycollegiate.com/gravityXa.htm
« Last Edit: February 21, 2018, 09:35:36 PM by E E K »

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #110 on: February 21, 2018, 09:35:51 PM »
Quote
easy peasy
The only way we can measure a planet's mass is through its gravity as per your link  - This needs a gravity model free of mathematical errors.
There are no known mathematical errors, apart from using Newtonian Gravitation in lieu of General Relativity. Apart from a minute discrepancy in the precession of the perihelion of the planet Mercury GR is not necessary.
There are some "errors" from other planets, but they are very small and depend on the inverse cube of the distance to the other object not the inverse square.
In any case, they can be corrected for when doing a detailed numerical simulation - a closed solution with three or more bodies is as yet not possible.

Quote from: E E K
Quote
Since Fsm > Fem after calculation therefore shouldn’t moon revolve the sun in its separate orbit?
This was my answer to that question from the previous post:

This bit is a very good question and is more than enough for one answer.

Part of the answer is that, as you say, the sun's gravitational field (gravity) near earth is greater than the gravitation field of the earth at the moon.
The sun's gravitational field (gravity) near the earth, however, changes only slightly over the radius of the moon's orbit around the earth.
In other words, the whole earth-moon system is attracted by the sun by almost the same amount, so the moon orbits the earth.
But, the earth-moon system travels around the sun at a much higher tangential velocity than the moon's velocity around the earth.

So the motion is an orbit around the sun at the same radius as the earth with just a little wriggle, with a period on one month, to make it orbit the earth.
This diagram, to scale, shows just half a month.

This just shows half a month. If I wanted to show a longer
time period, the motion of the Earth and moon around the
Sun would make it super-difficult to see the motion of the
moon relative to the Earth.
Read in detail in: WIRED, Does the Moon Orbit the Sun or the Earth?

There are many more references on this, as at first it seems a little puzzling.
Physics Stack Exchange, Why does the moon not revolve around the sun directly?
Then one that brings in Gravity Wells, EXPLAIN xkcd, Gravity Wells.
And there are plenty more. Just search for "Why does moon orbit the earth and not the sun?".[/b]
Quote from: E E K

There are 4 possibilities in the current model - impov

1- When the earth is in between the sun and moon: Shouldn't the combined effect of earth and sun alter the orbit of the moon and its speed as well

2- when the moon is in between earth and sun: Either Moon should fall to the sun instead of earth or at least there should be a reduction in its speed and the change in its orbit around the earth
There will be some effect, but what matters is not the absolute value os the sun's gravitational field near the earth, but on how much it changes during the moon's orbit.
The sun's "gravity" at the barycentre of the earth/moon system is what keeps the earth/moon system in orbit around the sun.

Quote from: E E K
3- Moon should revolve the sun in its separate orbit instead of orbiting the earth
No it shouldn't! That has been shown in all the above references.
It is not as though the moon is sitting stationary 384,400 km from the earth between the earth and the sun, it is orbiting the earth.
So half a lunar orbit later it will be on the far side of the earth, so being pulled closer to the earth.
In one orbit, the effects of the sun's gravitation cancel out.

Don't forget that
Quote
Out here, at the distance we orbit the sun, the gravitational pull of the sun is only 0.0006 of the strength of the earth's gravity on the surface of the earth.
or about 0.006 m/s2.

Quote from: E E K
4- The current orbit of the earth around the sun doesn't fit for both earth and moon if there is a combined effect of binary plates (earth and moon) on sun
It does fit perfectly well, though I can't follow your "combined effect of binary plates (earth and moon) on sun" is meant to mean.

Re: Are all masses like black holes?
« Reply #111 on: March 01, 2018, 11:28:08 AM »
Quote
It does fit perfectly well, though I can't follow your "combined effect of binary plates (earth and moon) on sun" is meant to mean.

We are going off the topic but shouldn't the radius of the orbit of binary planets (earth and moon) be greater than the greater current orbit of earth due to the combined effect.
Although binary planets (earth and moon) orbit around the sun but half of the moon cycle is in opposite direction while half of its cycle is along the direction of motion of barycentre in its orbit around the sun. So my question is why the orbital motion of the moon around earth doesn’t affect the speed as well as the position of barycentre around the sun in its orbit if the moon is influenced by both the “g” of sun and earth?

*

rabinoz

  • 19391
  • Real Earth Believer
Re: Are all masses like black holes?
« Reply #112 on: March 01, 2018, 04:38:20 PM »
Quote
It does fit perfectly well, though I can't follow your "combined effect of binary plates (earth and moon) on sun" is meant to mean.

We are going off the topic but shouldn't the radius of the orbit of binary planets (earth and moon) be greater than the greater current orbit of earth due to the combined effect.
What "combined effect"? Between the earth and moon, there is one gravitational force, Fem = G x Me x m[/i]m/dem2, where dem is the distance between the "centres of gravity" (simply the centres if they are spherically symetrical).
There is no separate Fme, that is the same force as Fem. It's almost as though gravitation were a piece of hypothetical elastic with force inversely proportional length squared.

Quote from: E E K
Although binary planets (earth and moon) orbit around the sun but half of the moon cycle is in opposite direction while half of its cycle is along the direction of motion of barycentre in its orbit around the sun. So my question is why the orbital motion of the moon around earth doesn’t affect the speed as well as the position of barycentre around the sun in its orbit if the moon is influenced by both the “g” of sun and earth?
For the earth-moon system what matters is not the absolute value of the sun's gravity near earth, but only the changes in that field around the moon's orbit.

So while the sun's gravity near the moon is about 0.0059 m/s2 and the earth's in only about 0.0027 m/s2 the variation in the sun's gravity is only about 1% of the earth's gravity at the moon.
         moon-sun (km)        Gravm-s         Change in Gravm-s        Gravm-e
min     149.3 x 106          0.00595 m/s2     0.000031 m/s2           0.0027 m/s2
avg     149.7 x 106          0.00592 m/s2      0.000000 m/s2           0.0027 m/s2
max    150.1 x 106          0.00589  m/s2    -0.000030 m/s2           0.0027 m/s2
So they are all affected, but only very slightly.