Topic: Hey Fake anon, if you're so smart, explain this..
Erik !saAqdaazn2 started this discussion 2 years ago #115,354
Anonymous B joined in and replied with this 2 years ago, 40 minutes later[^] [v] #1,273,964
Listen, my friend, let me break it down for you. The reason we don't fly off the spinning earth is because it moves smoothly and gravity keeps everything in place. Just like when you're cruising in a car at 60 miles per hour, you don't feel the movement. Same thing here. The strong gravity holds onto the atmosphere and us, so we don't go floating into space. It's actually pretty fascinating when you think about it! So, there you have it - rotation smoothness and gravity, that's why we don't feel like we're spinning. You gotta understand a bit of physics to really appreciate it! Capisce?Anonymous C joined in and replied with this 2 years ago, 9 hours later, 10 hours after the original post[^] [v] #1,273,999
The first two are examples of acceleration, which happens when something goes from a slow speed to a high speed. But as the rotation of the earth is consistent, we don't feel acceleration. If the earth was suddenly to stop spinning, we would be thrown sideways at 800 miles per hour and get turned into mush.
(Edited 35 seconds later.)
Fake anon !ZkUt8arUCU joined in and replied with this 2 years ago, 5 minutes later, 10 hours after the original post[^] [v] #1,274,000
Earth is a bagel not a matzo. I can't explain more than that without you converting first.
boof joined in and replied with this 2 years ago, 2 hours later, 13 hours after the original post[^] [v] #1,274,037
inertia, bubs
Anonymous F joined in and replied with this 2 years ago, 1 day later, 1 day after the original post[^] [v] #1,274,143
@1,273,999 (C)
> The first two are examples of acceleration, which happens when something goes from a slow speed to a high speed.
Yes, but no. There is a force of acceleration going from slow to high speed. A change of speed requires a change in acceleration. That is correct.
BUT a change in acceleration does not require a change in speed! Changing direction also requires acceleration. This acceleration, that is required for any object to maintain circular orbit, is supplied by something called a centripetal force. The centripetal force that keeps us on earth is gravity. On the amusement park ride Svet posted, it is supplied by the chains connected to the seats. And on the merry go round it's the bars that you hold on to. This force doesn't (Can't) go away once the ride is spun up to the final speed. It's not what happening in Svet's pictures (that it's simply spinning up or down in speed).
> If the earth was suddenly to stop spinning, we would be thrown sideways at 800 miles per hour and get turned into mush.
I think that's right. I think we'd be thrown along the surface of the earth, as if we suddenly accelerated whatever km/s it is where we are based on our distance from the north/south pole. I don't think we'd be thrown into space unless we're imagining gravity also disappears at that time.
@1,273,964 (B)
> Listen, my friend, let me break it down for you. The reason we don't fly off the spinning earth is because it moves smoothly and gravity keeps everything in place. Just like when you're cruising in a car at 60 miles per hour, you don't feel the movement. Same thing here.
I think that's pretty spot on. ALthough to be pedantic, I don't think the car analogy perfectly fits. Going straight at 60 mph you're not accelerating at all. But being held on earth, it's more like all the net forces sum to zero. Gravity providing the centripetal (and then some), then the ground providing the "and then some" balance left over in the opposite direction. That's not really the case of a car (in space, without air, going in a perfectly straight path with a spherical elephant driving it infinitely far from any other gravitating bodies), where there are truly zero forces.
Although GR is a whole different animal where we are VERY MUCH accelerating by simply sitting still on earth. Our clocks run slower and we experience all otherwise indistinguishable effects from accelerating through space at 9.8 m/s2
> The first two are examples of acceleration, which happens when something goes from a slow speed to a high speed.
Yes, but no. There is a force of acceleration going from slow to high speed. A change of speed requires a change in acceleration. That is correct.
BUT a change in acceleration does not require a change in speed! Changing direction also requires acceleration. This acceleration, that is required for any object to maintain circular orbit, is supplied by something called a centripetal force. The centripetal force that keeps us on earth is gravity. On the amusement park ride Svet posted, it is supplied by the chains connected to the seats. And on the merry go round it's the bars that you hold on to. This force doesn't (Can't) go away once the ride is spun up to the final speed. It's not what happening in Svet's pictures (that it's simply spinning up or down in speed).
> If the earth was suddenly to stop spinning, we would be thrown sideways at 800 miles per hour and get turned into mush.
I think that's right. I think we'd be thrown along the surface of the earth, as if we suddenly accelerated whatever km/s it is where we are based on our distance from the north/south pole. I don't think we'd be thrown into space unless we're imagining gravity also disappears at that time.
@1,273,964 (B)
> Listen, my friend, let me break it down for you. The reason we don't fly off the spinning earth is because it moves smoothly and gravity keeps everything in place. Just like when you're cruising in a car at 60 miles per hour, you don't feel the movement. Same thing here.
I think that's pretty spot on. ALthough to be pedantic, I don't think the car analogy perfectly fits. Going straight at 60 mph you're not accelerating at all. But being held on earth, it's more like all the net forces sum to zero. Gravity providing the centripetal (and then some), then the ground providing the "and then some" balance left over in the opposite direction. That's not really the case of a car (in space, without air, going in a perfectly straight path with a spherical elephant driving it infinitely far from any other gravitating bodies), where there are truly zero forces.
Although GR is a whole different animal where we are VERY MUCH accelerating by simply sitting still on earth. Our clocks run slower and we experience all otherwise indistinguishable effects from accelerating through space at 9.8 m/s2
(Edited 2 minutes later.)
Anonymous F double-posted this 2 years ago, 1 minute later, 1 day after the original post[^] [v] #1,274,144
@1,274,037 (boof)
Inertia would have you flying off into space in a straight line. Acceleration is the answer. Particularly due to gravity for earth.
Inertia would have you flying off into space in a straight line. Acceleration is the answer. Particularly due to gravity for earth.
boof replied with this 2 years ago, 10 minutes later, 1 day after the original post[^] [v] #1,274,145
Anonymous F replied with this 2 years ago, 20 minutes later, 1 day after the original post[^] [v] #1,274,146
@previous (boof)
I guess, in a way, with gravity.
But inertia alone isn't enough. It's not like spinning a ball in space where it'll keep spinning forever due to rotational inertia. I think that works out because it's spinning around its own center of mass (individual particles pushing and pulling each other to change their directions and then balancing each other out in turn). But that's not what we're doing here on earth since we're rotating about the earth's center of mass, not our own.
Angular momentum is pretty weird though https://www.youtube.com/watch?v=1VPfZ_XzisU
Let's not even get started on quantum spin states. There's something very strange going on there. I feel like physics just hasn't gotten to the bottom of it all.
This weirdness with rotating frames (rotating with respect to what? the fixed stars?) led to Mach's principle that then led to general relativity. Although general relativity still treats rotation as still something of a special thing, and arguably doesn't address some of the core questions raised by Mach's (vague) principle.
I guess, in a way, with gravity.
But inertia alone isn't enough. It's not like spinning a ball in space where it'll keep spinning forever due to rotational inertia. I think that works out because it's spinning around its own center of mass (individual particles pushing and pulling each other to change their directions and then balancing each other out in turn). But that's not what we're doing here on earth since we're rotating about the earth's center of mass, not our own.
Angular momentum is pretty weird though https://www.youtube.com/watch?v=1VPfZ_XzisU
Let's not even get started on quantum spin states. There's something very strange going on there. I feel like physics just hasn't gotten to the bottom of it all.
This weirdness with rotating frames (rotating with respect to what? the fixed stars?) led to Mach's principle that then led to general relativity. Although general relativity still treats rotation as still something of a special thing, and arguably doesn't address some of the core questions raised by Mach's (vague) principle.
boof replied with this 2 years ago, 37 minutes later, 1 day after the original post[^] [v] #1,274,149
all righty then
Anonymous F replied with this 2 years ago, 1 minute later, 1 day after the original post[^] [v] #1,274,150
boof replied with this 2 years ago, 1 minute later, 1 day after the original post[^] [v] #1,274,151
yes