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Moontanman

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Posts posted by Moontanman

  1. Michel - "duration = distance and infers motion" this is actually very profound and you deserve more recognition. Relativity theory does in fact require everything to be in motion otherwise it wouldn't exist.


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    Moontanman- "Time would be a fundamental dimension" - in my opinion this is just about the most profound piece of original thinking I have come across on this forum and much nearer to reality than you are being credited with.

     

    Thank you, I guess even a blind pig finds an occasional acorn.

  2. Gravity is a force, so everything effected by it must slow down whatever angle of travel.

     

    If I fire a firework into the air at an angle it returns to the earth because of gravity.

     

    If I fire the same rocket, do you honistly believe that the angle matters wether it returns to the earth? your saying that speed changes things and then things don't slow down ever.

     

    Actually gravity is not a force, what is the source of griff energy?

  3. If the planets will never slow down then it's griff energy doing its thing, else it's gavity energy doing it's thing and one day the planets will spiral to the sun guaranteed!

     

    Gaff, I'll say this one more time, there is nothing to slow down planets but friction, not enough friction to slow down planets over time scales that are meaningful to humans. so yes given enough time planets would indeed spiral into the sun but the sun and maybe even our universe will not exist long enough for this to happen.


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    So what you are saying is a aeroplane flying around the planet at 1 meter only travelling at 100 miles an hour stoped it's engine will fall to the earth guaranteed.

     

    But the same plane going at a very fast speed and turns off it's enging will never hit the earth?

     

    Yes, if there was no air, and no mountains higher than 100 feet and the airplane was going fast enough it would "never" hit the ground. Of course if there was no air it would not be an airplane now would it?

  4. if i jump i fall, how can going sideways at any speed stop me from EVER falling? EVENTUALLY as gravity is pulling i must slow down. This is where i just don't understand what you are saying.

     

    Gaff, it's already been said, the centrifugal force of the motion of the planets prevents gravity from pulling them in.

     

    Does the word "weightless" exist?

     

    It does but it should be micro gravity instead of weightless


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    I would think that as gravity is a constant force, this would be guaranteed.

     

    Nope, the exchange of energy between both bodies is different if they rotate and orbit in different directions. In the case of the Earth and Moon, they will move apart, the earth's rotation will slow down till both orbit with one hemisphere always facing each other. This will take longer than the sun will exist so don't look for it any time soon.

     


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    I would think that as gravity is a constant force, this would be guaranteed.

     

    EVERYTHING i know of 1 meter above the earths surface will fall without power EVENTUALLY regardless of how fast it is moving.

     

    Only because of friction gaff, only due to friction. If there was no air or mountains you could orbit at 1 Nano meter .


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    How can they not slow down but i do when I jump?

     

    This has been answered several times already gaff, i see no reason to do it again.

  5. Nope. You're not listening. The Moon is actually getting farther away from Earth as it orbits.

     

    Gravity doesn't slow down things in orbit, if they're in a circular orbit. They're going sideways, not up or down. It just pulls them into a circle.

     

    Capt'n, actually gravity can slow things down under the correct circumstances, if the Earth were rotating retrograde or the moon was orbiting retro grade gravitational friction would cause the moon to spiral into the earth, as a matter of fact it would already have happened not long after the formation of the moon.

  6. Then things everywhere are effected by gravity as stated by newtons law, so then EVENTUALLY the planets will spiral to the sun GUARANTEED!


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    The orbital motions of the planets negate the pull of gravity, the sun will not exist long enough for the orbits of the planets to deteriorate significantly due to friction with gas and dust in space.

     

     

    so in space, the ball spins FOREVER!?

     

    For all practical purposes , yes!

  7. Oh, I don't mean to turn Jupiter into a star. I mean converting a significant portion of its mass into energy. We use fission to ignite fusion in thermonuclear weapons. We use inertia as containment for certain fusion reactions. Jupiter has a lot of mass so a lot of inertia. Also it has hydrogen that is quite compressed already, especially at the core.

     

    Yes but still not enough to initiate self sustaining nuclear reactions and turn Jupiter into a star.

  8. Another way to look at it is if you could some how magically suspend your self in a box or space craft at 18,000 miles above the earth but be stationary with respect to the earth you would not float. you would still feel gravity, a much reduced gravity but gravity all the same. If your space ship and the earth were the only objects in the universe and you were 1 billion light years away but totally stationary in respect to the earth you would still feel a very very tiny pull from the earth, enough to eventually make you stick to the side of your space craft closest to the earth. Motion is what makes you float, not the absence of gravity.

  9. So a fired bullet at a speed less than escape velocity receives a constant force from the earths gravity and falls back to the ground.

     

    But a bullet fired faster than escape velocity still receives a force from earths gravity but is going too fast too be effected much by the gravity resistance and flyes off forever.

     

    Gravity is a force so makes me fall. Why does the escaped velocity bullet not eventualy fall too?

     

    Ignoring the friction of the air a bullet fired from a gun at normal "gun" velocities will arch up and over and hit the surface at the same speed it left the gun, gravity will slow it down as it achieves it's highest altitude but the speed will be regained as it falls back. A much higher muzzle velocity will allow the bullet to arch over and never hit the earth and stay in orbit, a higher velocity will allow the bullet to spiral away from the earth forever or at least until the suns gravity takes over and it goes into orbit around the sun. a much higher velocity and the bullet will escape he sun and go into orbit around the galactic core, even higher and it can leave the galaxy as well.

     

    If you could fire a gun with 0 radial velocity these ideas will change some what but in the real world that would be if not impossible very unlikely.

  10. Thats strange, so you fire a bullet at a speed below escape velocity and it slows down because of gravity.

     

    No it slows down due to friction with the air, if there was no air a bullet would arch over and hit the earth at the same speed it had when it left the muzzle of the gun.

     

     

    And if you fire a bullet faster than escape velocity it does not slow down and flyes off forever?

     

     

    In a word, yes! Actually the cap't is correct, but it would go on forever or at least into orbit around the sun until it hit another object. This effect is not why a bullet slows down how ever and if the bullet was fired just below escape velocity when it reached a certain point it would return to the earth (ignoring any friction) and hit with the velocity it had when it left.

     

    There so many assumptions here it is difficult to cover them all, any radial velocity of the bullet if it was less than escape velocity, would cause it to orbit the earth and not come back and hit the earth.

  11. But why does it not slow down because of the costant force of gravity? I do when I jump.

     

    Can I reach orbit at a height of a tree?

     

    Gravity holds the moon in orbit, since the moon is not moving away from the earth the earths gravity does not slow it down. Yes, barring the occasional hill or mountain and the friction of the air you could orbit at the height of a mouse if you had enough speed.

  12. So if i could go from 0 to escape velocity speed in a fraction of a second, i could turn off my engines before I reach the height of a tree and land on the moon?

     

    Yes, ignoring the friction of the atmosphere yes, if you indeed achieved escape velocity, no matter how quickly, you would indeed leave the earth but you would still be in orbit around the sun.


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    But why does it not slow down because of the costant force of gravity? I do when I jump.

     

    The moon does not slow down because it is in orbit, there is not enough friction from the interplanetary medium to slow it down over any realistic time frame. It's orbital speed keeps it in orbit, when you jump you never achieve even a small fraction of the necessary speed, friction from air is a real problem as well for your speed.

  13. It is known that once you reach outspace you are no longer effected by earths gravity, and the space men start to float inside there little space crafts.

     

    So how does the moon go around? Because of Griff Energy!

     

    NO! Earths gravity goes everywhere as does the gravity of everything else, men stay in orbit outside and inside their space craft because they are traveling at the same velocity as the space craft, no other reason! BTW it is not proper to say there is no gravity in space, it is called micro gravity.

     

    The moon stays in orbit due to it's centrifugal force exactly balancing the gravity of the earth, it's speed allows it to stay in orbit.

  14. ok, confusion with force and energy, so ill repeat.

     

    When I jump I use force, when im in the air going upwards i have energy.

    why does the force of gravity make me "lose" energy and return to the earth and why does the planets "not lose" energy because of the suns gravity force constantly being applied?

     

    The planet does not loose energy because you come back to earth, energy is conserved, if you could literally jump off the earth then the Earth would indeed loose a tiny (and I mean minuscule) amount of energy. That is the basis of using gravity assists when sending space craft to other planets. the amount of energy lost is so tiny it's totally negligible but it does happen.


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    Why does a firework once gone out fall back to the ground?

     

    How does one escape velocity?

     

    Fireworks fall back to the ground because they never even come close to achieving escape velocity, speed is what is necessary to achieve orbit and escape velocity. fire works never achieve the speed necessary to do anything but fall back down, just like you when you jump.

  15. ok, confusion with force and energy, so ill repeat.

     

    When I jump I use force, when im in the air going upwards i have energy.

    why does the force of gravity make me "lose" energy and return to the earth and why does the planets "not lose" energy because of the suns gravity force constantly being applied?

     

    Gaff, when you jump up you are not moving fast enough to do anything but fall back down, if you could jump fast enough you could achieve orbit or maybe even escape velocity. You just can't jump with enough force to over come the Earths gravity.

     

    The Earth doesn't fall into the sun because the earth is orbiting the sun fast enough to stay in orbit, if it wasn't it would spiral inward toward the sun.

     

    Anything in orbit around the earth is already traveling fast enough in relation to the sun to orbit the sun as well so the sun's gravity is negated by the motions of the earth in orbit. No force is necessary to drag the earth around.

     

    If you are in a space ship in orbit around the Earth (or on it) and you jump off it you stay in orbit because you are already traveling at orbital speed. Your jump puts you in a slightly different orbit and very very slightly changes the orbit of the space ship but you stay in orbit.

  16. Moontanman

    I wrote a full answer but lost it all before I could post so I'll just say yes is seems that way to us but unless GR is wrong it says we must view the orbit as a straight line in curved Space - in which case it does not rotate about its own axis other than a tiny residual oscillation from capture and reciprocal tidal effects.

     

    I see your point but it seems to me if the moon were to "loose" the bonds of earths gravity it would continue to rotate every 27.3 days.

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