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Re: Is Motion possible without Friction?
Posted: Sun Jan 05, 2014 7:35 pm
by Covalent
Blinky McSquinty wrote:That's not completely nonsensical, bbobeckyj, just asking good questions. But everything has to follow the laws of physics, the problem is that we don't know all of them, and may not be correct on some. A good part of theoretical physics is just that, it is just theory. Newton's theories were valid until they were replaced by Einstein's theories. And who knows, one day his theories may be proven incorrect or incomplete.
But what you are describing sounds like what happens in a black hole. If someone feel into it and actually remained in one piece and did not fry from the radiation, to that person time continues as usual. To the outside observer watching from just beyond the black hole's event horizon, the person falling into the black hole appears to slow down, slow down, and then cease all activity, time appears to have stopped. But it's all a complex relationship between gravity, time, and space.
Here's another weird thought and source of headache. Time is not the same for everyone, it runs differently based on their velocity. An airline pilot who flies at 600 MPH for a good part of his life actually lives longer than if he did not. The time difference is not much, but it's still there.
We hold to the concept that time marches on at a constant rate, and that it is constant throughout the entire universe. But it's not.
But while flying he's actually less under the gravitational effect and thus time moves faster so it would even out somewhat
Re: Is Motion possible without Friction?
Posted: Mon Jan 06, 2014 7:09 am
by chaz986
So in accord with blinky's post if I speed I live longer? Ho man I cannot wait to use that on the police if I ever get stoped.
Re: Is Motion possible without Friction?
Posted: Mon Jan 06, 2014 5:35 pm
by Covalent
chaz986 wrote:So in accord with blinky's post if I speed I live longer? Ho man I cannot wait to use that on the police if I ever get stoped.
Not necessarily, but your time will have moved slightly slower. If two men die at the precise age of 80, while one's been living his entire life in a fast plane, he will die a moment later than the other man who has lived a normal life.
Re: Is Motion possible without Friction?
Posted: Wed Jan 08, 2014 5:14 am
by Blinky McSquinty
chaz986 wrote:A frictionless engine would be very good ,a lot of energy is used up driving parts even though an engine runs on oil an oil pressure there is still a fair amount of drag caused by the oil even though many parts flot apon an oil film
Yes, and engineers do everything possible to reduce friction within an engine or any other component. They reduce the size of the bearing to the minimum (the larger the bearing, the more drag), use very thin lubricants, and manage every drop of oil within the engine. Every drop of oil that splashes against the crankshaft or rods is drag. So engine oil scavenging plays a major part in reduction of drag, and realizing more power coming off the crankshaft.
Re: Is Motion possible without Friction?
Posted: Thu Jan 09, 2014 7:36 pm
by chaz986
Blinky McSquinty wrote:chaz986 wrote:A frictionless engine would be very good ,a lot of energy is used up driving parts even though an engine runs on oil an oil pressure there is still a fair amount of drag caused by the oil even though many parts flot apon an oil film
Yes, and engineers do everything possible to reduce friction within an engine or any other component. They reduce the size of the bearing to the minimum (the larger the bearing, the more drag), use very thin lubricants, and manage every drop of oil within the engine. Every drop of oil that splashes against the crankshaft or rods is drag. So engine oil scavenging plays a major part in reduction of drag, and realizing more power coming off the crankshaft.
Having built sports engines for a few of my cars ,I have gained a good grasp of how hard work for what looks like a small gain in it self soon mounts up to overall a very potent package its not just in head work and gas flowing but in attention to things like you have said drag on the crank and oil flow and return
Re: Is Motion possible without Friction?
Posted: Mon Feb 17, 2014 5:53 pm
by Chunky
Having read two and a half pages and lost the will to live, I can reply simply to the original post.
Yes - motion is entirely possible without friction. As others have pointed out, anything moving in space or in a vacuum (without contact) is frictionless. Gravity is the best frictionless mode of propulsion.
Propulsion is possible without needing to invoke friction, e.g. hydraulic pistons, rockets, the mechanical effect of cogs on mountain railways, hot air balloons, springs, propellors, the list goes on.
No - tyres wouldn't work without friction. But if they were cog shaped and so was the ground, then forward movement would be no problem. Don't confuse friction with mechanical leverage.
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Re: Is Motion possible without Friction?
Posted: Fri Mar 07, 2014 1:10 pm
by Covalent
Chunky wrote:Having read two and a half pages and lost the will to live, I can reply simply to the original post.
Yes - motion is entirely possible without friction. As others have pointed out, anything moving in space or in a vacuum (without contact) is frictionless. Gravity is the best frictionless mode of propulsion.
Propulsion is possible without needing to invoke friction, e.g. hydraulic pistons, rockets, the mechanical effect of cogs on mountain railways, hot air balloons, springs, propellors, the list goes on.
No - tyres wouldn't work without friction. But if they were cog shaped and so was the ground, then forward movement would be no problem. Don't confuse friction with mechanical leverage.
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They are really the same thing.
Re: Is Motion possible without Friction?
Posted: Fri Mar 07, 2014 1:56 pm
by Skynyrd
Interesting topic.
Motion is perfectly possible in a frictionless world. The question seems to be if acceleration is possible.
If we consider gravitational pull the answer is obviously yes. Any orbiting object is continously accelerating.
Another obvious example is magnetism. If I were to hold a magnet close to an unmoving paper clip in a frictionless environment, the paper clip would still move towards the magnet so we would have accelaration.
And of course even simpler, at an atomic level movement and acceleration are constant. Heat makes atoms vibrate and thus accelerate, radioactive decay emits particles that accelerate initially, nuclear fusion in a star emits particles that accelerate initially, etc.
Of course we could get all philosophical and fancy and claim that if friction doesn't exist its due to the fact that, among others, electromagnetism doesn't exist which possibly means that weak and strong nuclear forces wouldn't exist which means that...duh, uninteresting scenario that leads nowhere; if the universe didnt exist why would this question even begin to be remotely interesting?