Is Gravitational Force Dependent on a Falling Object's Speed?
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From: Androcles on 7 Dec 2009 17:09 "Henry Wilson DSc ." <HW@..> wrote in message news:v8rqh5tp7pj3qvhfmdt64rdhrpb3r2miui(a)4ax.com... >I like asking sensible questions here because they usually bring out the >worst > in the people who try to answer them. This one will again test your > physics > knowledge. Bwhahahahahaha - thus spake the sensible man that wants to drop 300,000 km long pendula into neutron stars from a height of 300 million km and claims they'll swing. You have a strange notion of "sensible", Wilson. > It has always been assumed that the same force of gravity acts on a body > at > rest or in free fall at the same height. Is this true? I know Einstein's > silly > theory says there is a very small dependence on speed but what kind of > experiment would be able to detect such a dependence if there is one. Gravity decreases with altitude, since greater altitude means greater distance from the Earth's centre. All other things being equal, an increase in altitude from sea level to the top of Mount Everest (8,850 metres) causes a weight decrease of about 0.28%, which is 7 times greater than the 0.04% of CO2 in the atmosphere and therefore 7 times more sensible than AGW. A 180 lb man would weigh 179.5 lbs. However, all things are not equal. Comparative gravities in various cities around the world The table below shows the gravitational acceleration in various cities around the world; amongst these cities, it is lowest in Mexico City (9.779 m/s�) and highest in Oslo (Norway) and Helsinki (Finland) (9.819 m/s�). Amsterdam 9.813 m/s� Istanbul 9.808 m/s� Paris 9.809 m/s� Athens 9.807 m/s� Havana 9.788 m/s� Rio de Janeiro 9.788 m/s� Auckland 9.799 m/s� Helsinki 9.819 m/s� Rome 9.803 m/s� Bangkok 9.783 m/s� Kuwait 9.793 m/s� San Francisco 9.800 m/s� Brussels 9.811 m/s� Lisbon 9.801 m/s� Singapore 9.781 m/s� Buenos Aires 9.797 m/s� London 9.812 m/s� Stockholm 9.818 m/s� Calcutta 9.788 m/s� Los Angeles 9.796 m/s� Sydney 9.797 m/s� Cape Town 9.796 m/s� Madrid 9.800 m/s� Taipei 9.790 m/s� Chicago 9.803 m/s� Manila 9.784 m/s� Tokyo 9.798 m/s� Copenhagen 9.815 m/s� Mexico City 9.779 m/s� Vancouver 9.809 m/s� Nicosia 9.797 m/s� New York City 9.802 m/s� Washington, D.C. 9.801 m/s� Jakarta 9.781 m/s� Oslo 9.819 m/s� Wellington 9.803 m/s� Frankfurt 9.810 m/s� Ottawa 9.806 m/s� Zurich 9.807 m/s� You are lighter than Tusseladd even if you had the same mass. > > I say that since a gravity wave is thought to travel at 'c', the effect of > gravity on any moving object would take time to act. Therefore as the > falling > object approached c, the gravitational force would approach zero. > Maybe someone with a brain can suggest a possible experiment to > investigate > this. Anyone that actually had a brain would declare you insane, as I do. > A gravity field is similar to an electrostatic one, both diverging from a > point. False. http://upload.wikimedia.org/wikipedia/commons/7/78/GRACE_globe_animation.gif The force on an electric charge effectively falls off with the charge's > speed relative to the electrodes, supposedly because of an increase in > mass. > The real reason is that the Wilson Reverse Field Bubble builds up in the > space > around the charge, neutralizing the applied field and requiring a lot of > energy > to maintain. > > The question is, does a similar 'gravity bubble' form around a free > falling > object as its speed increases. If so, it should be possible to create an > anti-gravity field simply by accelerating an object at a high enough rate > for > the effect to become significant. > When do we get to the "sensible" part?
From: BURT on 7 Dec 2009 17:14 On Dec 7, 2:09 pm, "Androcles" <Headmas...(a)Hogwarts.physics_q> wrote: > "Henry Wilson DSc ." <HW@..> wrote in messagenews:v8rqh5tp7pj3qvhfmdt64rdhrpb3r2miui(a)4ax.com... > > >I like asking sensible questions here because they usually bring out the > >worst > > in the people who try to answer them. This one will again test your > > physics > > knowledge. > > Bwhahahahahaha - thus spake the sensible man that wants to drop > 300,000 km long pendula into neutron stars from a height of 300 million > km and claims they'll swing. You have a strange notion of "sensible", > Wilson. > > > It has always been assumed that the same force of gravity acts on a body > > at > > rest or in free fall at the same height. Is this true? I know Einstein's > > silly > > theory says there is a very small dependence on speed but what kind of > > experiment would be able to detect such a dependence if there is one. > > Gravity decreases with altitude, since greater altitude means greater > distance from the Earth's centre. All other things being equal, an increase > in altitude from sea level to the top of Mount Everest (8,850 metres) causes > a weight decrease of about 0.28%, which is 7 times greater than the 0.04% of > CO2 > in the atmosphere and therefore 7 times more sensible than AGW. A 180 lb man > would weigh 179.5 lbs. However, all things are not equal. > > Comparative gravities in various cities around the world > The table below shows the gravitational acceleration in various cities > around the world; amongst these cities, it is lowest in Mexico City (9.779 > m/s²) and highest in Oslo (Norway) and Helsinki (Finland) (9.819 m/s²). > > Amsterdam 9.813 m/s² Istanbul 9.808 m/s² Paris 9.809 m/s² > Athens 9.807 m/s² Havana 9.788 m/s² Rio de Janeiro 9.788 m/s² > Auckland 9.799 m/s² Helsinki 9.819 m/s² Rome 9.803 m/s² > Bangkok 9.783 m/s² Kuwait 9.793 m/s² San Francisco 9.800 m/s² > Brussels 9.811 m/s² Lisbon 9.801 m/s² Singapore 9.781 m/s² > Buenos Aires 9.797 m/s² London 9.812 m/s² Stockholm 9.818 m/s² > Calcutta 9.788 m/s² Los Angeles 9.796 m/s² Sydney 9.797 m/s² > Cape Town 9.796 m/s² Madrid 9.800 m/s² Taipei 9.790 m/s² > Chicago 9.803 m/s² Manila 9.784 m/s² Tokyo 9.798 m/s² > Copenhagen 9.815 m/s² Mexico City 9.779 m/s² Vancouver 9.809 m/s² > Nicosia 9.797 m/s² New York City 9.802 m/s² Washington, D..C. 9.801 > m/s² > Jakarta 9.781 m/s² Oslo 9.819 m/s² Wellington 9.803 m/s² > Frankfurt 9.810 m/s² Ottawa 9.806 m/s² Zurich 9.807 m/s² > > You are lighter than Tusseladd even if you had the same mass. > > > > > I say that since a gravity wave is thought to travel at 'c', the effect of > > gravity on any moving object would take time to act. Therefore as the > > falling > > object approached c, the gravitational force would approach zero. > > Maybe someone with a brain can suggest a possible experiment to > > investigate > > this. > > Anyone that actually had a brain would declare you insane, as I do. > > > A gravity field is similar to an electrostatic one, both diverging from a > > point. > > False. > http://upload.wikimedia.org/wikipedia/commons/7/78/GRACE_globe_animat... > > The force on an electric charge effectively falls off with the charge's> speed relative to the electrodes, supposedly because of an increase in > > mass. > > The real reason is that the Wilson Reverse Field Bubble builds up in the > > space > > around the charge, neutralizing the applied field and requiring a lot of > > energy > > to maintain. > > > The question is, does a similar 'gravity bubble' form around a free > > falling > > object as its speed increases. If so, it should be possible to create an > > anti-gravity field simply by accelerating an object at a high enough rate > > for > > the effect to become significant. > > When do we get to the "sensible" part? If there is a circular orbit then there isn't any acceleration and no strength of gravity. Mitch Raemsch
From: Androcles on 8 Dec 2009 06:43 "Henry Wilson DSc ." <HW@..> wrote in message news:hsgrh5ds14vidho73j0iabrjrtlo1keani(a)4ax.com... > On Mon, 7 Dec 2009 22:09:25 -0000, "Androcles" > <Headmaster(a)Hogwarts.physics_q> > wrote: > >> >>"Henry Wilson DSc ." <HW@..> wrote in message >>news:v8rqh5tp7pj3qvhfmdt64rdhrpb3r2miui(a)4ax.com... >>>I like asking sensible questions here because they usually bring out the >>>worst >>> in the people who try to answer them. This one will again test your >>> physics >>> knowledge. >> >>Bwhahahahahaha - thus spake the sensible man that wants to drop >>300,000 km long pendula into neutron stars from a height of 300 million >>km and claims they'll swing. You have a strange notion of "sensible", >>Wilson. >> >> >>> It has always been assumed that the same force of gravity acts on a body >>> at >>> rest or in free fall at the same height. Is this true? I know Einstein's >>> silly >>> theory says there is a very small dependence on speed but what kind of >>> experiment would be able to detect such a dependence if there is one. >> >>Gravity decreases with altitude, since greater altitude means greater >>distance from the Earth's centre. All other things being equal, an >>increase >>in altitude from sea level to the top of Mount Everest (8,850 metres) >>causes >>a weight decrease of about 0.28%, which is 7 times greater than the 0.04% >>of >>CO2 >>in the atmosphere and therefore 7 times more sensible than AGW. A 180 lb >>man >>would weigh 179.5 lbs. However, all things are not equal. >> >>Comparative gravities in various cities around the world >>The table below shows the gravitational acceleration in various cities >>around the world; amongst these cities, it is lowest in Mexico City (9.779 >>m/s�) and highest in Oslo (Norway) and Helsinki (Finland) (9.819 m/s�). >> >> Amsterdam 9.813 m/s� Istanbul 9.808 m/s� Paris 9.809 m/s� >> Athens 9.807 m/s� Havana 9.788 m/s� Rio de Janeiro 9.788 m/s� >> Auckland 9.799 m/s� Helsinki 9.819 m/s� Rome 9.803 m/s� >> Bangkok 9.783 m/s� Kuwait 9.793 m/s� San Francisco 9.800 m/s� >> Brussels 9.811 m/s� Lisbon 9.801 m/s� Singapore 9.781 m/s� >> Buenos Aires 9.797 m/s� London 9.812 m/s� Stockholm 9.818 m/s� >> Calcutta 9.788 m/s� Los Angeles 9.796 m/s� Sydney 9.797 m/s� >> Cape Town 9.796 m/s� Madrid 9.800 m/s� Taipei 9.790 m/s� >> Chicago 9.803 m/s� Manila 9.784 m/s� Tokyo 9.798 m/s� >> Copenhagen 9.815 m/s� Mexico City 9.779 m/s� Vancouver 9.809 m/s� >> Nicosia 9.797 m/s� New York City 9.802 m/s� Washington, D.C. 9.801 >>m/s� >> Jakarta 9.781 m/s� Oslo 9.819 m/s� Wellington 9.803 m/s� >> Frankfurt 9.810 m/s� Ottawa 9.806 m/s� Zurich 9.807 m/s� >> >> >>You are lighter than Tusseladd even if you had the same mass. >> >>> >>> I say that since a gravity wave is thought to travel at 'c', the effect >>> of >>> gravity on any moving object would take time to act. Therefore as the >>> falling >>> object approached c, the gravitational force would approach zero. >>> Maybe someone with a brain can suggest a possible experiment to >>> investigate >>> this. >> >>Anyone that actually had a brain would declare you insane, as I do. >> >> >> >>> A gravity field is similar to an electrostatic one, both diverging from >>> a >>> point. >> >>False. >> >> http://upload.wikimedia.org/wikipedia/commons/7/78/GRACE_globe_animation.gif >> >> >> >> The force on an electric charge effectively falls off with the charge's >>> speed relative to the electrodes, supposedly because of an increase in >>> mass. >>> The real reason is that the Wilson Reverse Field Bubble builds up in the >>> space >>> around the charge, neutralizing the applied field and requiring a lot of >>> energy >>> to maintain. >>> >>> The question is, does a similar 'gravity bubble' form around a free >>> falling >>> object as its speed increases. If so, it should be possible to create an >>> anti-gravity field simply by accelerating an object at a high enough >>> rate >>> for >>> the effect to become significant. >>> >>When do we get to the "sensible" part? > > You have completely missed the point of the question. > Like I said, my sensible questions bring out the worst in some people. > It's certainly brought out the worst in you. If sci.physics.research accepts your post I'll be surprised.
From: xxein on 8 Dec 2009 23:53 On Dec 7, 5:09 pm, "Androcles" <Headmas...(a)Hogwarts.physics_q> wrote: > "Henry Wilson DSc ." <HW@..> wrote in messagenews:v8rqh5tp7pj3qvhfmdt64rdhrpb3r2miui(a)4ax.com... > > When do we get to the "sensible" part? xxein: You two never will. You two have little knowledge of current physical theory and even less of the physic as it ultimately manifests itself.
From: Paul B. Andersen on 10 Dec 2009 07:39
Henry Wilson DSc wrote: > On Tue, 8 Dec 2009 20:53:47 -0800 (PST), xxein <xxein(a)comcast.net> wrote: > >> On Dec 7, 5:09 pm, "Androcles" <Headmas...(a)Hogwarts.physics_q> wrote: >>> "Henry Wilson DSc ." <HW@..> wrote in messagenews:v8rqh5tp7pj3qvhfmdt64rdhrpb3r2miui(a)4ax.com... >>> >>> When do we get to the "sensible" part? >> xxein: You two never will. You two have little knowledge of current >> physical theory and even less of the physic as it ultimately manifests >> itself. > > Is that your best answer to my questions? Your question is meaningless. In a Newtonian world the gravitational force doesn't depend on the speed of the object, as you well know. In GR there is no such thing as "gravitational force" which can depend on velocity. But you are obviously thinking of the fact that the path of a particle in a gravitational field deviates from what Newton predicts. (Bending of light!) That falsifies Newton's theory of gravitation, which can't be saved by any kind of Rabbidgian reverse thought bubbles. -- Paul http://home.c2i.net/pb_andersen/ |