What Exactly would happen if the Moon decided to fly off?

  • 39 Replies
  • 13700 Views

0 Members and 1 Guest are viewing this topic.

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
Apart from there being no tides of course..

I also read that there would be no more evolution, somehow.. Because apparently we evolved from a fish or something, and we only got exposed outside or something because of the tides! But I don't think it makes much senser!

Would there be a catastrophe if one day the moon decided to fly off? [???]
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline turnipsock

  • Hero Member
  • *****
  • 586
  • Beekeeper to the unsuspecting
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #1 on: 28/03/2008 17:11:39 »
The Earth would probably fly into the sun.

I think the earth and moon are a bit like a hammer thrower, so when the hammer (moon) is thrown, the thrower (earth) falls backwards.
Beeswax: Natures petrol tank sealant.

When things are in 3D, is it always the same three dimensions?

*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #2 on: 28/03/2008 19:05:15 »
The earth and moon are linked to each other and orbit the sun as one body.

Also the moon may look  large but it contains very little mass compared to the earth and therefore if the moon were to dissapear the resulting loss of mass from the earth moon system would only cause a very small and minor change to the earths orbital characteristics around the sun.

If the moon were to dissapear it would however cause chaos to the earths weather systems as the moon helps stabilize the tilt of the earth.
« Last Edit: 28/03/2008 20:14:45 by ukmicky »

*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #3 on: 28/03/2008 22:07:08 »
The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #4 on: 28/03/2008 22:39:17 »
Quote
All that counts is the present radius and speed, not the Mass.


As the two bodies orbit around a common centre wouldnt the removal of that common centre cause a  minor change? .
« Last Edit: 28/03/2008 22:54:35 by ukmicky »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #5 on: 28/03/2008 22:45:35 »
The Earth would probably fly into the sun.

I think the earth and moon are a bit like a hammer thrower, so when the hammer (moon) is thrown, the thrower (earth) falls backwards.

The Earth would fly into the sun? I'm sure that wouldn't happen... =/
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #6 on: 28/03/2008 22:46:18 »
The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

I don't know.. I heard that the Moon is gradually moving away from the Earth, and one day it will wander off.. We're talking millions of years.
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #7 on: 28/03/2008 23:14:13 »
The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

I don't know.. I heard that the Moon is gradually moving away from the Earth, and one day it will wander off.. We're talking millions of years.

The moon will continue to move away from the earth as it robs energy from the earth through tidal action. The energy it gets is robbed from the spin of the earth and as a consequence the spin of the earth around its axis is slowly slowing down.

However i believe this will stop and the moon will no longer be able to rob energy from the earth and they will both show each other the same face just like how to moons rotation slowed down to a point that it now show us the same face all the time ,something like that ..
« Last Edit: 28/03/2008 23:26:51 by ukmicky »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #8 on: 28/03/2008 23:15:02 »
So the moon will never separate from us?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #9 on: 28/03/2008 23:18:48 »
Dont think so. By that time anyway the sun will be no more just like the earth and moon.
« Last Edit: 28/03/2008 23:32:38 by ukmicky »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #10 on: 29/03/2008 12:41:30 »
Isn't it like 6 billion years before the sun burns off?
Also, is the burning of the sun constant?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline rosalind dna

  • Neilep Level Member
  • ******
  • 2019
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #11 on: 29/03/2008 13:16:09 »
I can't imagine the moon flying away as you titled your thread,
Seany.
Because it is the Earth's satellite and if it could or did then the seasons as well as the tides would become chaotic and uncotrollable also I guess that the earth's pull of gravity might have something to do with it.
Rosalind Franklin was my first cousin and one my life's main regrets is that I never met this brilliant and beautiful lady.
She discovered the Single DNA Helix in 1953, then it was taken by Wilkins without her knowledge or agreeement.

*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #12 on: 29/03/2008 14:06:55 »
Isn't it like 6 billion years before the sun burns off?
Also, is the burning of the sun constant?
The moon i believe is moving away from us at present around 1 inch a year ,so in 6 billion years the moon would only be 152 400 killometers further away.

 However in reality the figure will be less than that because the further away the moon gets the less the earth feels its gravity ,so over time the ammount of energy the moon will be able rob from the earth will decrease meaning the distance that the moon is moving away each year is slowly decreasing.
« Last Edit: 29/03/2008 14:33:12 by ukmicky »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #13 on: 29/03/2008 14:07:54 »
152400 kilometres is alot!! or is that not far enough for it to come out of orbit?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #14 on: 29/03/2008 14:28:27 »
Not really at present the moon is 384,402 km away from us. If you were to make the sun everlasting at some stage in the future the moon would stop moving away and the face of the earth and moon would be tidally locked just like Pluto and its moon Charon

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #15 on: 29/03/2008 14:29:55 »
But 150,000km is almost half that distance
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #16 on: 29/03/2008 14:30:00 »
But its no a lot as far as orbits go and also as i said it will not be that much because the distance that the moon is receding each year is decreasing.


http://www.astro.uu.nl/~strous/AA/en/antwoorden/getijden.html

http://burro.astr.cwru.edu/stu/planets_dwarf_pluto_moons.html
« Last Edit: 29/03/2008 20:37:25 by ukmicky »

*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #17 on: 29/03/2008 23:00:33 »
If we are talking about a simple system with just Sun, Earth and Moon the angular momentum must remain constant so, because the Sun is so massive, the orbit times should not change.
With some of these threades I can't be sure whether the simple question to the simple model is required (that should be answered first, in any case) or the clever clogs question which seeks to examine just one of the additional effects on a system. If we're talking about eons in the future, then we should include effects of other planets too.
We could try to encourage more closed questions, perhaps or, early on in threads, we could try to rephrase original questions in a more fruitful way. There can be too many open ended, rambling discussions which don't really add to the sum of human knowledge.

*

Offline Make it Lady

  • Neilep Level Member
  • ******
  • 4050
  • Hands-on fun for everyone!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #18 on: 30/03/2008 21:21:20 »
So the TV programme 'Space 1999' where the moon leaves the Earth's orbit, due to an explosion on its surface, taking the people on its moon base with it is a load of old twaddle?
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #19 on: 30/03/2008 21:55:47 »
The particularly twaddlish bit was that they kept meeting people on their journey.
Any explosion that would knock the Moon out of its orbit would have to propel a lot of material in the other direction (action and reaction). Such acceleration would have left a lot of surface stuff behind, including the cast of the series, who were standing on the surface.
Not a good idea to carry these thought experiments to their logical conclusion.
« Last Edit: 30/03/2008 21:59:56 by sophiecentaur »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #20 on: 30/03/2008 22:07:19 »
What about if the explosion caused the moon lose half its mass?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #21 on: 30/03/2008 22:10:07 »
That 1/2 mass would have to go somewhere at some speed. The total momentum and angular momentum would still remain unchanged.

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #22 on: 30/03/2008 22:10:58 »
The orbit time would also remain unchanged?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline Make it Lady

  • Neilep Level Member
  • ******
  • 4050
  • Hands-on fun for everyone!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #23 on: 30/03/2008 22:14:08 »
On the programme the explosion didn't seem to remove any mass. The moon was pushed out of orbit by some weird Newton's Third law of motion effect!!!
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #24 on: 30/03/2008 23:20:13 »
The orbit time would also remain unchanged?
the orbit time of what? The half that went off in one direction would have a different orbit and the other bits would have their own orbits. Earth wouldn't have to change significantly if the event was short lived. The reason I say that is because the force on the Earth would start off as the existing gravitational attractive force and then drop to zero at a huge separation distance. The change of momentum of Earth would be equal to this force times the time it acted for. Less time - less momentum change. For an explosive event, the change would be slight.
Imagine trying to drag a magnet across a table with another magnet; if you whipped your magnet away quickly, you couldn't budge it - you'd need to keep your magnet close for a long time and 'tease' the other magnet along. The Moon scenario would be the same sort of idea.

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #25 on: 30/03/2008 23:57:25 »
The orbit time would also remain unchanged?
the orbit time of what? The half that went off in one direction would have a different orbit and the other bits would have their own orbits. Earth wouldn't have to change significantly if the event was short lived. The reason I say that is because the force on the Earth would start off as the existing gravitational attractive force and then drop to zero at a huge separation distance. The change of momentum of Earth would be equal to this force times the time it acted for. Less time - less momentum change. For an explosive event, the change would be slight.
Imagine trying to drag a magnet across a table with another magnet; if you whipped your magnet away quickly, you couldn't budge it - you'd need to keep your magnet close for a long time and 'tease' the other magnet along. The Moon scenario would be the same sort of idea.

The half that flies away.. Forget about it.

The half that stays in orbit.. Would that one still orbit the earth once every 28 days?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline turnipsock

  • Hero Member
  • *****
  • 586
  • Beekeeper to the unsuspecting
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #26 on: 31/03/2008 00:24:47 »
Actually, this question isn't that daft. There have been a number of plans to explode an atomic bomb on the moon.

If the earth and moon orbit the sun as one mass, then we got rid of the moon, the mass would have decreased and the earth would then drift away from the sun.

I have a lot of pictures of the moon taken with the TSGT if anybody is interested. Its good to keep pictures to remind us what things looked like when they are gone.

Isn't the moon's mass an 1/8 of the earths?
« Last Edit: 31/03/2008 00:27:42 by turnipsock »
Beeswax: Natures petrol tank sealant.

When things are in 3D, is it always the same three dimensions?

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #27 on: 31/03/2008 10:26:11 »
If the earth and moon orbit the sun as one mass, then we got rid of the moon, the mass would have decreased and the earth would then drift away from the sun.

Yes yes yes! This is what I thought. But apparently even if the mass of the moon went down, it would find another orbit..
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #28 on: 31/03/2008 10:26:30 »
But why would there be plans to blow up the moon with an atomic bomb?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline turnipsock

  • Hero Member
  • *****
  • 586
  • Beekeeper to the unsuspecting
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #29 on: 31/03/2008 17:17:14 »
But why would there be plans to blow up the moon with an atomic bomb?

I don't think it was to blow it up but a show of stength during the cold war. Both the Americans and Russians had plans to do this.

http://en.wikipedia.org/wiki/Project_A119

http://www.svengrahn.pp.se/histind/E3/E3orig.htm

The americans idea was to produce a mushroom cloud that would be visable from earth!
Beeswax: Natures petrol tank sealant.

When things are in 3D, is it always the same three dimensions?

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #30 on: 31/03/2008 17:17:58 »
Would it have actually made the Earth fall out of orbit of the Sun?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #31 on: 31/03/2008 20:49:42 »
Quote
If the earth and moon orbit the sun as one mass, then we got rid of the moon, the mass would have decreased and the earth would then drift away from the sun.
That is just nonsense. The orbit diameter might change by a minuscule amount because of the change of position of the 'mutual centre of mass' of E,S &M. The most basic orbit theory tells you that the mass of a minor object in orbit is not relevant to its orbit time. What counts is its kinetic energy relative to its gravitational potential energy - mass is a common factor in each and is irrelevant. I could write down the sums but the web is full of this sort of elementary theory; mass just doesn't come into the orbit formula for small objects.
A simple argument goes like this - if you reducfe the mass then there is less gravitational force BUT the mass it acts on has decreased pro rata - no net effect.
« Last Edit: 31/03/2008 20:51:30 by sophiecentaur »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #32 on: 31/03/2008 20:55:23 »
Wouldn't a smaller mass be further away from the thing it's orbitting?
They say that when you die, your life flashes in front of you. Make it worth watching!


*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #33 on: 31/03/2008 22:14:08 »
Why would it?
To go round in a circle of a certain diameter requires a certain amount of force per kilogram of the object. Each kilogram of the object experiences a pro-rata force keeping it in that orbit.
A pea doesn't require much force to keep it in a particular orbit but its attraction is a small force. A Centurion tank will need much more force to make it follow the same orbit but, because its mass is so great, it gets much more atttractive force. If the two are going at the same tangential speed, they will orbit at the same distance.
It all depends on where and at what speed they started off, if you like.
Just why they go in nearly circular orbits and why the orbits of all the planets are the way they are is a more complicated matter but let's start with the basics.

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #34 on: 31/03/2008 23:01:49 »
Because if a small mass.. Such as something that ways 100 tonnes. Which is pretty light for something like a meteorite or something. If that was to have an orbit with the sun, and was close to the sun.. The sun's gravitational pull would drag it straight in.

So for the small mass of block thing to orbit the sun, it must be far off, where the sun's gravitational pull is further away..
They say that when you die, your life flashes in front of you. Make it worth watching!


*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #35 on: 01/04/2008 11:54:49 »
'fraid that's wrong still. Oh ye of little faith!
The effect on the motion of a mass depends upon the force and the value of the mass (Newton's second law of motion).
In the same way as orbits are independent of mass,  objects of low and high mass both fall to Earth at the same rate. (Well know experiment and you can more or less prove it for yourself if your light object is not so light that air resistance starts to have an effect - no feathers).
Here's chapter and verse ( you need to wait for A level before they do this at School for you. The Maths is reasonable, though, and is a clincher!!):
Centripetal force needed to keep an object in a circular path of radius r at speed v is
F(centripetal) = mv*v/r - like a conker on a string.

Force attracting it towards the Sun (Sun's Mass = M, G is the Gravitational Constant)
F(gravitational) = m*M*G/r*r

When the object is in a stable orbit, these two forces are equal / balanced, so the object won't move away or towards the Sun, just stay moving in a circle.
so
m*v*v/r = m*M*G/r*r
the m's cancel and so does one of the r's
so:
v*v = M*G/r
re-arrange it to find the radius of orbit
r=M*G/v*v
m doesn't come into it; all that counts is the speed. This assumes that M is a lot, lot bigger than m, which it is and is the simplest case of a circular orbit - but it applies for elliptical orbits too.
« Last Edit: 01/04/2008 11:59:41 by sophiecentaur »

*

Offline Seany

  • Neilep Level Member
  • ******
  • 4209
  • Live your life to the full!
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #36 on: 01/04/2008 22:58:19 »
Way too complicated for my likings..

But I think I'm getting it. [:P]
They say that when you die, your life flashes in front of you. Make it worth watching!


*

Offline turnipsock

  • Hero Member
  • *****
  • 586
  • Beekeeper to the unsuspecting
    • View Profile
What Exactly would happen if the Moon decided to fly off?
« Reply #37 on: 01/04/2008 23:55:56 »
'fraid that's wrong still. Oh ye of little faith!
The effect on the motion of a mass depends upon the force and the value of the mass (Newton's second law of motion).
In the same way as orbits are independent of mass,  objects of low and high mass both fall to Earth at the same rate. (Well know experiment and you can more or less prove it for yourself if your light object is not so light that air resistance starts to have an effect - no feathers).
Here's chapter and verse ( you need to wait for A level before they do this at School for you. The Maths is reasonable, though, and is a clincher!!):
Centripetal force needed to keep an object in a circular path of radius r at speed v is
F(centripetal) = mv*v/r - like a conker on a string.

Force attracting it towards the Sun (Sun's Mass = M, G is the Gravitational Constant)
F(gravitational) = m*M*G/r*r

When the object is in a stable orbit, these two forces are equal / balanced, so the object won't move away or towards the Sun, just stay moving in a circle.
so
m*v*v/r = m*M*G/r*r
the m's cancel and so does one of the r's
so:
v*v = M*G/r
re-arrange it to find the radius of orbit
r=M*G/v*v
m doesn't come into it; all that counts is the speed. This assumes that M is a lot, lot bigger than m, which it is and is the simplest case of a circular orbit - but it applies for elliptical orbits too.

so the orbit of the earth is really about velocity? Increase the velocity and the earth drifts outwards to new orbit, decrease the velocity and the earth goes into a lower orbit. (I'm not sure 'velocity' is the correct term, 'speed' may be better)
Beeswax: Natures petrol tank sealant.

When things are in 3D, is it always the same three dimensions?

*

Offline ukmicky

  • Moderator
  • Neilep Level Member
  • *****
  • 3011
    • View Profile
    • http://www.space-talk.com/
What Exactly would happen if the Moon decided to fly off?
« Reply #38 on: 02/04/2008 22:20:37 »
'fraid that's wrong still. Oh ye of little faith!
The effect on the motion of a mass depends upon the force and the value of the mass (Newton's second law of motion).
In the same way as orbits are independent of mass,  objects of low and high mass both fall to Earth at the same rate. (Well know experiment and you can more or less prove it for yourself if your light object is not so light that air resistance starts to have an effect - no feathers).
Here's chapter and verse ( you need to wait for A level before they do this at School for you. The Maths is reasonable, though, and is a clincher!!):
Centripetal force needed to keep an object in a circular path of radius r at speed v is
F(centripetal) = mv*v/r - like a conker on a string.

Force attracting it towards the Sun (Sun's Mass = M, G is the Gravitational Constant)
F(gravitational) = m*M*G/r*r

When the object is in a stable orbit, these two forces are equal / balanced, so the object won't move away or towards the Sun, just stay moving in a circle.
so
m*v*v/r = m*M*G/r*r
the m's cancel and so does one of the r's
so:
v*v = M*G/r
re-arrange it to find the radius of orbit
r=M*G/v*v
m doesn't come into it; all that counts is the speed. This assumes that M is a lot, lot bigger than m, which it is and is the simplest case of a circular orbit - but it applies for elliptical orbits too.

so the orbit of the earth is really about velocity? Increase the velocity and the earth drifts outwards to new orbit, decrease the velocity and the earth goes into a lower orbit. (I'm not sure 'velocity' is the correct term, 'speed' may be better)
Angular momentum is the word or words  your looking for

*

lyner

  • Guest
What Exactly would happen if the Moon decided to fly off?
« Reply #39 on: 03/04/2008 12:54:45 »
Quote
(I'm not sure 'velocity' is the correct term, 'speed' may be better)
I think I do mean velocity - I should have said tangential velocity. Then the attractive force produces an acceleration towards the centre - no change of speed but a change in velocity (i.e. direction).

Quote
Angular momentum is the word or words  your looking for
   
Except that introduces a new concept and a new formula and I was trying to keep it simple. I don't think the misconception would have arisen if seany was very familiar with angular momentum.