But the key here is that the person WOULD have to rotate, representing the plane rotating nose down to keep up with the circle.there is no rope - the fixed link is a rigid link, attached to the person by a harness and is allowed to rotate on the upright poll by use of roller bearings
the person can only move forward or backward, along the dotted line (imagine the fixed link is a mile long)
But the key here is that the person WOULD have to rotate, representing the plane rotating nose down to keep up with the circle.
The plane will rotate, but it won't have to take any action to do so. Gravity will take care of it. Imagine transporting a pendulum from London to Los Angeles. Would you have to rotate it through 90 degrees to get it to hang straight down when you arrived?But the key here is that the person WOULD have to rotate, representing the plane rotating nose down to keep up with the circle.
*Ah, that old argument again... I think they've heard the term 'flight level' and decided level = flat, whereas it actually means we fly perpendicular to the centre of gravity. So no, we don't 'constantly nose down', Otto* just keeps us nice and perpendicular to CoG
There are a few problems with this.
Let's say you can take 3 steps straight forward before reaching the end of the rope. After taking those 3 steps, what do you have to do to continue your way around the circle?
Also a plane flying at 35,000 feet still has plenty "rope" left to go.
Then how did the plane leave the surface of the earth? I know, it's complex physics but fact is, it still gave itself some slack.No, the "rope" is always tight. There's no slack.
But the key here is that the person WOULD have to rotate, representing the plane rotating nose down to keep up with the circle.
the plane is a spirit level. no matter where it goes it remains level to the center of the earth, just as the spirit level does.representing the plane rotating nose down to keep up with the circle.
it lifted it's nose and used "thrusters" to ascend to the desired altitude. the rigid rope analogy only works when flying level ie once the plane gets to altitude then levels off.Then how did the plane leave the surface of the earth?
I don't see how that is theoretically possible. That's like saying the earth doesn't curve, but is still a sphere.I think the crux of the problem Provemewrong, as Trailblazer has succinctly put it
is that gravity is an invisible force acting on the plane
I have just tried to replicate it in my analogy by making the "force" a visible rigid link to the upright pole
but the result is the same - the person will simply walk (straight) forward, but in fact he/she will end up going around the pole
I really like this comparison. For me to visualize better let's replace the pendulum with the spirit level. Let's pretend there's no elevation on earth, just the smooth curved surface. You are saying it would be possible (in theory) to travel the surface of the spherical earth without the level ever changing ?The plane will rotate, but it won't have to take any action to do so. Gravity will take care of it. Imagine transporting a pendulum from London to Los Angeles. Would you have to rotate it through 90 degrees to get it to hang straight down when you arrived?
the problem is the scale. walking around a maypole with a 10 foot pole attached to you is alot different then the size of the earthbut the result is the same - the person will simply walk (straight) forward, but in fact he/she will end up going around the pole
Absolutely but a circle is a circle and you can't make one without rotation/curvature (or change in direction). If the person has to shift the way their nose is pointing to trace the circle, then so does the plane.the problem is the scale. walking around a maypole with a 10 foot pole attached to you is alot different then the size of the earth
Yes. Now please show me how the plane takes that path without its nose following the dotted line.here we go
any better
i hear you, it is counterintuitive for me too. but look at the toy, the plane doesnt move or tilt. it remains in it's exact same position no matter where it is on the circle.Absolutely but a circle is a circle and you can't make one without rotation/curvature (or change in direction). If the person has to shift the way their nose is pointing to trace the circle, then so does the plane.
Yes. Now please show me how the plane takes that path without its nose following the dotted line.
Yes but gravity still would have to bring the nose in line with the dotted flight path. There is no way the nose can stay pointed perfectly to the right the entire circle.it is being held there by gravity
In the pic, are the noses not pointing in opposite direction? They can't get that way without change.i hear you, it is counterintuitive for me too. but look at the toy, the plane doesnt move or tilt. it remains in it's exact same position no matter where it is on the circle.
look at the horses then. the horses are parellel to the "earth" ie the side of the carousel. they remain in exactly the same parellel position no matter where they move on the carousel.In the pic, are the noses not pointing in opposite direction? They can't get that way without change.
Parellel yes but there are not facing the same way. The entire time. I think what the argument is coming down to is RELATIVE direction.[/QUOTE]look at the horses then. the horses are parellel to the "earth" ie the side of the carousel. they remain in exactly the same parellel position no matter where they move on the carousel.
Yes but gravity still would have to bring the nose in line with the dotted flight path. There is no way the nose can stay pointed perfectly to the right the entire circle.
they are facing the same way really, but that doesnt matter. the sides of the horses remain parallel to the carousel base, just as the bottom of the plane remains parallel to the earth surface. Turn the carosel on its side so the horses are in a plane position to better see it.Parellel yes but there are not facing the same way
Only if the earth is flat lol. The horses are not facing the same direction from the cameras point of view. The camera is on the same room, which we can compare to the sky.does it help if you image someone on the plane holding a spirit level - level
why would the spirit level remain level when the plane has flown another qtr round the earth
well when the plane is on the right side of the globe its tail fin is pointing right and when the plane is on the left side of the globe it's tail fin is pointing left.. if we were on the moon watching it from a still camera.Only if the earth is flat lol. The horses are not facing the same direction from the cameras point of view. The camera is on the same room, which we can compare to the sky.
Correct. But in order for that to be the case the plane has change direction at some point ( at least from our perspective on the moon).well when the plane is on the right side of the globe its tail fin is pointing right and when the plane is on the left side of the globe it's tail fin is pointing left.. if we were on the moon watching it from a still camera.
Correct. But in order for that to be the case the plane has change direction at some point ( at least from our perspective on the moon).
Would the perspective not be the same from the sky as the moon? ( other than size and visibility)outside perspective, that's irrelevant. if you look at the carousel toys above. the plane, or horse, or helicopter themselves stay in the exact same position at all times.
They stay "level" .
Let it stew in your brain a bit. maybe @tadaaa can add more planes at 2o'cock and 8o'clock to his graphic above.to help you visualize more.
if you walk around a maypole with a taut 10 foot rope and keep your left shoulder exactly parallel to the maypole, would your perspective change? no. your body would be in the same relation to the pole as it was 45degrees earlier. your view (the scenery) would change.Would the perspective not be the same from the sky as the moon? ( other than size and visibility)
i think your second pic is going to throw him as he wont realize that the "flatish" 100 miles will "move" with the plane.Here's a scale diagram of a plane at 36,000 feet (7 miles up) flying 100 miles in level flight.
i think your second pic is going to throw him as he wont realize that the "flatish" 100 miles will "move" with the plane.
no, my understanding is both the pane and the person walk/fly forward as normal - there is no "rotating"
Thank you! I was working on a diagram, just hadn't finished it. So it is a slightly curved path.Here's a scale diagram of a plane at 36,000 feet (7 miles up) flying 100 miles in level flight.
Planes fly along slightly curved paths. They stay approximately the same height above sea level when in level flight. That's all.
https://ggbm.at/Exam7fne