Subject: Re: [LPNY DISCUSS](OT) Mr. Science bad Date: Mon, 29 Sep 2003 19:00:01 -0400 To: From: Bob Armstrong Blay , Given your more accurate than the average here insights about this off topic , I'm surprized you were unfamiliar with the notion of angular velocity , generally measured in radians per second which makes the linear speed ( directionless velocity ) equal to the angular velocity for a unit circle ; the circumference of the unit circle , 2 pi , defining the number of radians . By Kepler's law which I stated in Message 19426 , if the radius of an orbit is increased by 1.1 times , the period increases by 1.1 ^ 3%2 or about 1.1537 . So the speed decrease to 1.1 % 1.1537 or about 0.9535 of the original . I have not had the product of time and interest to grok orbital energetics , but it's clearly not as simple as just saying the speed goes down as r ^ 2 . Obviously Kepler found it to be r % r ^ 3%2 as I had in my table in message 19428 . -- On Mon, 29 Sep 2003 08:42:40 -0400, Blay Tarnoff wrote: >=A0Blay Tarnoff wrote: >=A0> >=A0>=A0[W]hen the moon's angular velocity slows, say, 10% due to >=A0>=A0a higher orbit, its linear velocity slows 10% as well. > >=A0Hmmm.... actually, scratch this statement. =A0As the moon moves= into a >=A0higher orbit, if its linear velocity were to stay the same, its= angular >=A0velocity would be slower. =A0Likewise, if its angular velocity= were to >=A0stay the same at the higher orbit, its linear velocity would= have to >=A0increase to keep the same rate of movement per arc. > >=A0So, as the moon moves X% further from the Earth, its linear= velocity >=A0slows by X*2 (X squared) due to the lower gravity and its= angular >=A0velocity slows by X in addition to that due to the increased= distance or >=A0X*3 in total. =A0So, for example, if the moon were to move 10%= farther >=A0from the Earth, its linear velocity would slow by 1.21 times= (=3D17.36%) >=A0and its angular velocity would slow by 1.331 times (=3D24.87%).= =A0Is that >=A0right? > >=A0Of course, all of this still boils down to the fact that, as= the moon >=A0moves farther away, both its linear and angular velocities= decrease. >=A0One does not increase while the other decreases. > >=A0Blay > >=A0------------------------------------------------- > >=A0Blay Tarnoff wrote: >=A0> >=A0>=A0Interesting. =A0I never heard of angular velocity before. =A0I= would think >=A0>=A0that in a circle, though, angular velocity and velocity would= be the >=A0>=A0same measurement, since each degree traces a fixed unit of= length. >=A0>=A0(IOW, since every degree is X miles long, saying that one is= traveling >=A0>=A0at one degree/minute, e.g. is really just saying that one is= traveling >=A0>=A0at X miles per minute.) =A0So, when the moon's angular velocity= slows, >=A0>=A0say, 10% due to a higher orbit, its linear velocity slows 10%= as well. >=A0> >=A0>=A0Blay >=A0> --=A0 =A0Bob Armstrong -- http://CoSy.com -- 212-285-1864 Return our Right to Relax : =A0http://ny.lp.org/cgi-bin/petition.cgi?Against_the_Smoking_Ban Computing Environment : =A0http://CoSy/CoSy/ A WTC vision : http://CoSy.com/CoSy/ConicAllConnect/ Liberty : http://CoSy.com/Liberty.htm =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A02003/09/29 5:28:38 PM