pzkpfw

What's the difference? On Monday night you go to bed. You wake up Tuesday morning; you know who you are, you remember your fifth birthday party, and what you had for dinner on Monday. On Tuesday night you go to bed. During the night, gas is used to knock you out and keep you asleep while you are "perfectly replicated". Every atom in your body is duplicated. The original you is then made into Soylent green. You wake up Wednesday morning; you know who you are, you remember your fifth birthday party, and what you had for dinner on Tuesday. Is Wednesday "you" really "you"? Well, is there any real difference? Your muscles have been replicated, your bones have been replicated, your mind has been replicated. If you walk like a duck and quack like a duck, you're a duck.

No, I'm not suggesting any link between G1 and G2. After the copy, G1 and G2 do not have any connection and will not feel or experience anything from each other. All I'm saying is that (given the assumption of perfect replication) G1 and G2 are indistinguishable (up to that point, not afterwards, as their experiences differ). Both will consider themselves as "the" G. If G1 is vaporised, G2 will happily continue being G. If I step onto a transporter, and am re-made on Mars while my "original" on Earth is vaporised, the "copy me" on Mars will happily continue being "the" me.

But given the assumption of perfect replication, at the moment of replication Graeme 2 pretty much is Graeme 1. He'll have the same memories and the same personality. He'll know he is the "copy", because he's the one who steps out of the transporter, but other than that, he'll consider himself "Graeme". Hardly different from waking up from a deep dreamless sleep. You wouldn't know that during your sleep you were "transported". What if during the night, every one of your atoms were replaced? You wake up, you still remember what you had for dinner the day before. Are you still you? I'd step into the transporter, if it were proven (by earlier, braver people) to be as safe as any other transportation system.

That's not useful, nor is it information.

Many (not all) of the cells we have today are not made of the same atoms we had x years ago (it depends on which cells). So we are already pretty much our grandfathers' axe. (The one where the head's been replaced a few times, and so has the handle, but it's still the "same" axe). Since consciousness is an emergent property of our brains, given "perfect" replication, I'd suggest there'd end up being two of the replicated person, both considering themselves that person and having shared memories, but from that moment on generating their own separate memories, and developing their personalities (separately, possibly in diverging ways) according to their different experiences. No biggie. (But I do find it interesting to consider - if I met a replicated me, would I like myself?)

Don't feed the troll.

Yep. An example I was thinking of when I wrote that, was that readings "near" each other would tend to show two levels, for people indoors and people outdoors (with variations of course). Kind of like how Lidar readings can show the lowest trimmed level of a forest.

Most Raspberry Pi's will be indoors. Homes (I'd assume, at least those that have these devices) are generally heated and insulated. We'd maybe get some good data, but it may not be about climate change. ( If all cellphones recorded temperature and position (e.g. so they'd know they were outdoors), reporting to a central location, that might be good. But all the caveats about data quality would apply. You'd even need to guard against malicious data. )

Unicorns. Clearly you are looking for Unicorns. I give up.

So far, the answer is clearly no. Simply trying to reverse a bunch of science and going back to claiming centrifugal force is real is contributing nothing. You may as well try to argue Earth stands still and the Sun orbits us.

If the centrifugal force were real, there would be a real force outwards on something being kept moving in a circle. And if so, when that force is removed (e.g. that string being cut) that thing would move outwards, not at a tangent. (The only time you appear to see outwards movement is when you constrain that movement in your tube.) Just stand somewhere with bare feet. Feel your weight on your feet. It's true that your mass attracts the Earth, but you have much much less mass than it. So where does that feeling of weight on your feet come from? (Stand on sharp gravel if you need to be reminded of that weight.) Is that 80 kg coming from the Earth "pulling you down" or are you pulling the Earth up? Or stand against a cliff face, push hard on it. Yes, the cliff is feeling the force of your push - but where is the force coming from? If the cliff suddenly vanished - you'd fall forward. If you suddenly stopped pushing on the cliff, would it jump forward? A force felt in opposition to another force may seem interchangeable, but there's a reason why science labels some forces fictitious and some real. There may well be times or scenarios when pretending centrifugal forces are real is useful. It's not uncommon to pick and choose reference frames for ease in some situations. For example, we would calculate most experiments on Earth pretending Earth is sitting still, not rotating, orbiting, etc. The only "problem" is when you start treating your frame of convenience as the "real" one, and ignore the real physics of what's going on.

Remember that experiment with the ball on the string, and how when the string was cut, the ball went off at a tangent? (Not outwards). That would be the equivalent of your merry go round, if there was suddenly zero friction between it and the coin. At the opposite end of the scale, if the friction was "enough", the coin wouldn't move at all (relative to the merry go round). In between, where the friction exists, but isn't enough to counter the momentum of the coin, the coin will appear to slide outwards (relative to the merry go round), as it tries to follow it's straight line course. The exact amount of friction will determine the path - but as noted above it will be a spiral, relative to the merry go round. At no time will there be a real outwards (centrifugal) force. (Edit: there might be a very specific balance of speed (perhaps needing continuous variable adjustment) of merry go round rotation, friction and coin weight where you'd get that spiral to be an apparent radial - but that (if even possible) would be a special case, not a proof of a general principle.) Well, yeah, these experiments are easy. That's why modern science came to the conclusion it did about centrifugal vs. centripetal force. (Argument by authority is of course bogus, but do you really think this simple experiment would have the outcome you expect, and all of science has missed the conclusion you expect? Nobody has noticed? Really?)

Swinging a pipe by hand is hardly "accurate", any odd motion on the lizard (did I write that?) is hard to pin on modern science having a misunderstanding of forces. Besides, you're using tubes. That tube is itself putting forces on the object inside the tube. You've seen in the experiment with the string that gets cut, that there is no outwards motion put on the object. What's different with your tube is that the "rear" (in terms of the direction of rotation) wall of the tube is putting forces on the object (and as the tube is rotating, that force won't be directly in line with the objects momentum at any moment). That object, is trying to go in a straight line, and relative to that line the tube is giving it a slope to move along. The tube is acting as a ramp, and giving the object some momentum outwards of that straight line. Even exiting the tube will have some effect. As the object gets to the end of the tube, the lip of the tube will be the last thing putting forces on the object, which itself may not be an ideal shape. That'll also have some effect on the "leaving the tube trajectory". Any "outwards" component of the motion of the object, once it leaves the tube, is not evidence of centrifugal force. It's evidence of a flawed experiment.

Cosmoquest forum (formerly BAUT (Bad Astronomy and Universe Today)) has a special rule for its ATM (Against The Mainstream) section, where threads are automatically closed after 30 days. ("Automatically" here means a moderator has to do it manually, but it's standard practice.) The thread starter can make a plea by report-to-the-mods to have a thread reopened - giving reasons why. It doesn't happen often, which to my mind suggests the closure is usually a good idea. It seems to work well as a policy.

"What pushes you?" : Nothing. There is no force "pushing" you. "What force overcame the force of friction?" : Your inertia. As the merry-go-round spins, your inertia means your body wants to keep going in a straight line. The friction with the surface allows a centripetal acceleration to be applied, that keeps you going in the circle. As it speeds up, it's harder to keep you going in that circle. The force of the friction is not enough and you start to slide (outwards, it seems, but essentially trying harder and harder to go in a straight line). The centripetal force is no longer enough to counter the inertia. It's the same answer. Again and again.

tar, try this: Think about artificial gravity in a space station. Like in the Movie 2001: A Space Odyssey. The space station is circular (a ring in the movie, but you could do the same with a cylinder), and is spinning. The crew can walk on the inside, of the outside wall, and seem to feel a kind of "gravity". Where does this force come from? If it's centrifugal, that implies something is actually pushing outwards (away from the centre of the circle) on them. What is that? Is it the air in the space station? No. As noted umpteen times herein, the truth is that the force applied on them is inwards. It's centripetal. Their bodies, due to their momentum (mass x velocity, remembering velocity is speed with direction), naturally want to continue in a straight line. The floor of the space station, turning in it's circle, is applying a force on them that keeps them turning in that same circle. That force is felt as the artificial gravity. Yes ... that person in the artificial gravity does seem to feel a force outwards. (The direction of the "gravity" they feel). Just like your boy on the roundabout and the finely tuned fluid in his inner ear. But ... that's not a "real force", nothing is pushing outwards on the space station crew member. What they feel is the reaction to the inwards force that's keeping them going in that circle. (And just like the ball on the string in the video a few forum pages ago - if a large section of the space station outer wall suddenly broke away, it and the crew member standing on it would not fly off into space directly away from the centre of rotation; they'd go in a direction tangential to the circle at that point. Things want to go in straight lines; at the moment the centripetal acceleration is removed, what's left is their momentum - and the tangent to the circle is the direction of that momentum.)

No. Look at your base disk of clay side-on. Note that the centripetal acceleration keeping the blobs going in the circle is applied one way at the bottom of the toothpick, the momentum of the ball is applied in the other direction, at the top of the toothpick. That's what produces the rotation that makes the toothpick tip over. You are misrepresenting the case. There is no force outward, but that doesn't mean there won't be apparent (in reference to the circle) motion outwards. Strings and toothpicks will constrain that motion. As shown in the earlier video, if a string is cut, the blob will move off at a tangent to the circle, not directly (radially) outwards. If you spun your disk fast enough that the toothpicks came right out of the base, your blobs too would fly off (more or less) at a tangent. All that point mass stuff is, well, pointless.

Yeah, you're still not getting it. The blob seems to have moved radially "outward" from the base, but that's not what happens. The blob has tried to go in a straight line while the base has gone inward (the circle).

I don't think anybody is arguing against what it seems like. The term centrifugal, e.g. as in "centrifugal clutch", wouldn't exist otherwise. It just turns out that's not (i.e. outwards force) what's really happening. You've made a complex scenario - with the toothpick standing upright in the clay at the start. The centripetal acceleration attempting to keep the blob going in a circle ends up putting a rotation of that toothpick (in the plane of the rotation: the base of the toothpick isn't in line with the blob at the end of it), and the clay holding it gives way. It still isn't evidence of centrifugal force.

Your language is a bit sloppy here, but close enough (heck, mine's not perfect). We can see there are two factors at play, the momentum (mass x velocity) of the object - it wants to go in a straight line - and the centripetal force. The resulting velocity (force is required to change momentum, which is a vector quantity) means the object travels in that circle. Given that, now think about what would happen if that centripetal force was just a little bit too small. What would the object do? No! You suddenly introduce a centrifugal force when there's no need to. What's happened here, is that with the higher rotational speed, a higher centripetal force is needed to keep the mass in that circle. The desire of that mass to go in a straight line is stronger, as it's going faster, so more centripetal force is needed. It doesn't move out because some centrifugal force pushes it out, it appears to "move out" because there isn't enough centripetal force to keep it in. (What eventually happens depends on what's applying the centripetal force (spring, elastic, whatever)). If the object in question is moving in a circle, then more or less, yes. No, there is no centrifugal (outwards) force. After all, where would it come from? Is the spring or elastic holding the mass suddenly pushing on that mass in a significant way? The mass wants to keep going straight, if the centripetal force is too small, the mass will try to.

No. There is no outward force, there's only the inclination of an object to move in a straight line.

This is where you seem so keen to find something "clever" you descend into gibberish. You're way over-complicating this. If you need to specify exotic conditions that were not stated in the question, why then even bother saying "yes"? Edit: and on second thought, "yes" can't be right anyway, as the object is moving off at a tangent to the circle, and that laser is shining out from the centre of the circle. It can't work regardless of where the wheel stops. The ball will either be moving parallel to the laser, or the path of the ball and the laser will cross at exactly one point. Again, over thinking the whole thing. Of course yes, and no (in that order). That's all pretty obvious. But none of that was really the original point of this thread. Why does the rate increase? Taking that video from a few posts ago as an example, the speed at which the ball leaves the wheel (tangentally) will be the speed of the circumference of the wheel at the time the ball was let go.

No. You're the same as the ball in that video. Not sure. I'd have to do some math. It's not an "exact alignment", as the ball moves off at a tangent, and the wheel rotates. Curves are different to straight lines. The width of the ball will determine how long the laser hits it. Certainly, the ball moves away from the wheel, but a tangent is different to a radial motion, and the main thing to get over in thinking about all this is that there is no real force outwards radially in this situation - otherwise the ball in that video would not have gone up when that string was cut.

The rest of your post goes a bit off the deep end, I think, but here you do have the crux of it. When you say "by getting the rope to go taught" you are showing the force needed to make the object go in a circle is towards the centre. At any moment, the direction of momentum of the object is at a tangent to the circle. It's the force towards the centre, whether by string or gravity or the thing is on the inside of a rim (e.g. space station "artificial gravity", see "2001: A Space Odyssey" for visuals) that keeps the thing going in a circle. There is no real force outwards, that's just the "opposite" of the force needed to make the thing keep going inwards.

Because you're standing on a circle (slice of the sphere), that's turning. The surface is dropping away. The natural inclination of your body is to keep moving in a straight line. The reason you don't, as the surface drops away, is gravity. So while you'd "weigh less" at the equator than at one of the poles *, it's not because there's some force pulling you up (as hinted at in post #168 by Tar), it's because the surface, relative to you, is moving down. (* actually it's a lot more compicated than that, as Earth isn't a perfect spehere of even density, but that's beyond this thread. (And me.)) Edit (not directly about the post above but very much about this thread): Watch this video: https://www.youtube.com/watch?v=O6yJG_fnJRc Then think about why, when the string is cut, the ball goes up (in the direction of the tangent to the wheel), not horizontal, in the direction of the centre to the ball (i.e. the string).