Heater wrote: ↑
Mon Jun 04, 2018 11:05 am
Yes, it sounds wrong, more on that below.
The difference in the roational situations of fair ground rides and plannets is significant. In the faiground case there is a force in the connection to the pod, the pod and it's occupants feel an acceleration. In the planet case the planet, Earth say, is connected to the sun by gravity but the planet, and we on it, do not feel any force. As you say, it seems we are in free-fall. Why is this?
It points to the idea that gravity is a very different thing than the other forces we know of. The force provided by that fairground ride basically comes down to electricity, the attraction and replusion of the atomic parts of the connecting rod due to the electic field.
One major differenc is that there is no "negative" for gravity as there is for other forces. Another difference is that it acts on all things that have mass (or energy) in the same way, it's not fussy.
I think it was these considerations that led Einstein to his "Priciple of Equivalence".
It all sounds wrong. Why?
To my mind a rotataing system is a stable system. It goes around and around, at the same rate and around the same axis, forever (barring some energy input or output we are ignoring for now).
davidcoton claimed: "The rotation does not cause acceleration. Acceleration causes rotation." I might claim the opposite. But really neither makes any sense to me. Which ever is causeing the other the revese must also be true, because it's a stable system, nothing about it changing over time. Except the instantaneous position of the parts, but the thing is symetrical about it's axis, thows positions are essentially the same.
A similar stable system of action and reaction is the famous harmonic oscillator, the pendulum. The fact that it has momentum at the bottom of the swing causes it to swing up to the highest place it can. The fact that it has potential enery at the top of the swing causes it to drop back to the bottom. Ad infinitum. In our analysis this has no beginning and no end, so which cases which.
As I said "chickens and eggs".
This all points to something even deeper. In the laws of physics there is no cause and effect. We like to see causes and effects as ordered in time. The cause happens first the effect happens later as a result. But the laws of of physics work exactly the same if time runs backwards. It's impossible to tell which is cause and which is effect.
Until we come to thermodynamics that is, but that is another story...
In 1983 a buddy from my university, Steve Housego, stood as a candidate in Lewisham. He called himself 'The Assassin's Bullet'. He got 173 votes.