Scientists unveil a physics-defying curved space robot
- Reference: 1660255211
- News link: https://www.theregister.co.uk/2022/08/11/curved_space_robot/
- Source link:
The researchers were able to generate momentum without a surface to push off from by building a robot isolated from outside influences and confined to a curved space. In a video the machine can be seen shifting a pair of motors attached to a piece of curved track, slowly moving itself without any external force.
[1]Youtube Video
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"What our research demonstrates is that it's possible to acquire a sort of velocity, and hence move forward, without acquiring any momentum," lead researcher and Georgia Tech assistant physics professor Zeb Rocklin told The Register .
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"The caveat, though, is that this is only possible in a curved spacetime. We supplied the curvature by sticking our robot on a sphere."
Curved space is a fundamental part of modern physics, and is essential to understanding general relativity. For humans, who move in three relatively flat dimensions, Newton's third law dictates that each force has an equal and opposite one. This is how rockets get their trust, how we're able to jump, and how cars move down the road.
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In curved space, forces differ; In their [6]paper , the team said that objects in curved space should theoretically be able to move without frictional or gravitational forces.
To minimize the influence of flat space physics on the robot, the team mounted it to a shaft supported by air bearings and bushings. The shaft was also aligned to earth's gravity to eliminate residual force.
The robot did face slight frictional and gravitational forces, which hybridized with the curvature of its track "to produce a strange dynamic with properties neither could induce on their own," Georgia Tech [7]said . According to the institution, the forces on the robot during the tests were predominantly due to its curved environment.
What do you do with a curved-space robot?
Watching the video of the robot in action may be a bit underwhelming, but even moving fractions of an inch it's still doing something important, the researchers claim.
As one example, Rocklin said that the research done by his team relates to studies into "impossible engines," like the experimental EmDrive.
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First proposed in 2006, [9]the EmDrive uses microwaves in a vacuum chamber to theoretically create thrust by bouncing against a surface. [10]Tests performed at TU Dresden found that thrust reported in initial EmDrive experiments was due to the test unit's interaction with Earth's gravitational field, and didn't indicate the device would actually work.
Rocklin told The Register that the EmDrive would "seriously break physics" were it to work, as there would be no way for it to gain momentum, something that his curved-space robot overcomes.
Curved space could theoretically get the EmDrive moving, Rocklin said, but at far too small a degree to be experimentally detectable. "To see movement via this effect you'd need far greater curvature, such as that present in the vicinity of a black hole," Rocklin told us.
[11]You cannae break the laws of physics, cap'n... Boffins call BS on 'impossible' black hole, fear readings were botched
[12]You wanted flying cars and colony worlds. Instead, IKEA furniture-building-ish AI robots
[13]Think your phone is snooping on you? Hold my beer, says basic physics
[14]Watch it go: World's smallest self-folding origami bird that reminds us we were promised nanobots at some point
To explain the similarity, the researchers pointed to GPS systems, which rely on slight gravity-induced frequency shifts to report locations to satellites. "While the effects are small, as robotics becomes increasingly precise, understanding this curvature-induced effect may be of practical importance," Georgia Tech said.
Rocklin's shuffling robot may not move far, but the curved bit of "space time" it operates on isn't that curved. Like looking at the ocean horizon, it's pretty difficult to see the curvature of the Earth when viewed from up close.
Apply those principles to black holes, where space is theoretically curved more than anywhere else in the known cosmos, and the system could become practical.
"Ultimately, the principles of how a space's curvature can be harnessed for locomotion may allow spacecraft to navigate the highly curved space around a black hole," Georgia Tech said. With the [15]nearest suspected black hole sitting over 3,000 light years from Earth, it'll be a while before we can test that. ®
Get our [16]Tech Resources
[1] https://www.youtube.com/watch?v=gMZSWKKt9Yw&t=4s
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YvXQZ7Gzo0k2w6H68s2@NAAAAJQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YvXQZ7Gzo0k2w6H68s2@NAAAAJQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YvXQZ7Gzo0k2w6H68s2@NAAAAJQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YvXQZ7Gzo0k2w6H68s2@NAAAAJQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[6] https://www.pnas.org/doi/abs/10.1073/pnas.2200924119
[7] https://research.gatech.edu/robotic-motion-curved-space-defies-standard-laws-physics
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YvXQZ7Gzo0k2w6H68s2@NAAAAJQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[9] https://www.theregister.com/2016/04/21/em_drive_theory_why/
[10] https://www.theregister.com/2018/05/23/emdrive_flunks_test/
[11] https://www.theregister.com/2019/12/12/black_hole_rebuttal/
[12] https://www.theregister.com/2019/11/21/ai_robot_ikea/
[13] https://www.theregister.com/2021/10/18/information_wants_to_be_free/
[14] https://www.theregister.com/2021/03/19/self_folding_nanotechnology/
[15] https://www.bbc.com/news/uk-england-cambridgeshire-44500291
[16] https://whitepapers.theregister.com/
Re: "didn't indicate the device would actually work. "
i.e. experimentally demonstrated that the device didn't work.
Re: "didn't indicate the device would actually work. "
Absence of positive does not equal presence of negative. I can’t believe it takes a legally trained tax nerd to point this stuff out on a forum where you’d expect people to be quite good on logical thought and stuff.
Re: "didn't indicate the device would actually work. "
I think that in the case of the em drive 'Russell's Teapot' applies.
You invented a machine that does magic, in all the tests it didn't do magic. Claiming that I didn't definitively prove there is no magic is a bit of a stretch.
If you're that close to a black hole moving without anything to push against would be the least of your worries.
Inertia of energy as an anchor in space
This gets complicated, but all motion in space requires movement in time. That in turn relates to energy transfer from point to point in space. One could then use a large mass as anchor in time to leverage against moving a smaller mass in space and time. Thus a black hole could be used as an anchor for a space drive in the near time vicinity.
One could also anchor against energy in an E or M field, as the field itself has a kind of inertia in places where it has energy in it. That is, you can use points having energy, within E/M fields, as anchors you can push against, as all E/M waves require fluctuations of energy on a point to point basis propagating through space. In other words, energy itself has inertia and thus can be a stable point to push against. I am trying not to seem handwavish, but this is somewhat complex. Remember that waves carry energy and waves have to propagate through space and time. By carrying energy they in effect can be anchor points to push or pull against. Yes, this implies there can be tractor beams too.
That looks just like how I move my wheeled chair across the floor, just swing my legs and varying speeds. In fact, that's how you impart motion to yourself on a swing. Have they just invented the swing?
Am I missing something?
From the overhead view, the centre of mass moves toward the 'gate post' when the vertical weights move as far as they can from each other..
So, if the centre of mass is near the post, when the horizontal masses move to the right and then stop, they will have applied a force on the horizontal arm, moving it left in proportion to the relative mass of the horizontal mass...
What I am struggling to convey is an idea of the leverage of the horizontal arm.
Stand on some ice next to a child's roundabou and hold the outside edge of it.t . Have a friend stand near the centre of the roundabout. Now use your arms to slide yourself a quarter of the way round the outside of the roundabout. If this crap analogy works, you will have moved relative to the ground and the roundabout will have moved the opposite way relative to the ground. The amount the roundabout and your friend have rotated will be proportional to the centre of mass of the roundabout and the leverage you get from the radius of the roundabout. Now get your freind to move tt the edge of the roundabout in a straight line so any newtonian opposite force he generates will be directed through the axis of the roundabout and so it will not cause the roundabout to rotate.
Now, if you pull yourself back around that quarter of the roundabout. Because the mass of your friend is now at the edge of the roundabout , you have less leverage to move him, so the roundabout will move less relative to the ground and you will move further relative to the ground.
Get your friend to move back to the centre of the roundabout and you, the roundabout and friend are now all back in your relative positions to each other, but the whole apparatus has eotated from it's initial position relative to the floor.
Sorry if your feet got cold.
Flat out wrong
GPS systems, which rely on slight gravity-induced frequency shifts to report locations to satellites
No. They rely on the time it takes a signal to reach it from the satellites to determine the distance to that satellite, then it triangulates using multiple satellites and their known positions.
Locations are not reported to satellites, either.
The whole article sounds like buzzword bingo.
Re: Flat out wrong
The article just piles wrong upon wrong. Here are the examples I found most egregious:
the EmDrive uses microwaves in a vacuum chamber to theoretically create thrust
Early on there was a paper describing how EM Drive was supposed to work. There was a very obvious error in the mathematics: not accounting for the angle when microwaves reflected from an angled surface. The solution to this problem was to delete the paper and not give any explanation for how EM Drive was supposed to work. In theory EM Drive produces zero thrust. In practice any flaw in the experimental design shows up as a microscopic amount of thrust.
Tests performed at TU Dresden found that thrust reported in initial EmDrive experiments was due to the test unit's interaction with Earth's gravitational field
Wrong again. The link to the [1]article on TheRegister actually gets it right:
They found that "magnetic interaction from twisted-pair cables and amplifiers with the Earth’s magnetic field can be a significant error source for EMDrives."
I just watched the video and it was an omnishambles. As soon as I saw the device I was expecting friction drive: friction is slightly higher when not moving than when there is motion. The usual trick is to accelerate an internal mass quickly enough to overcome static friction and slide a bit then to return the mass with a slower acceleration that does not overcome static friction. This setup is so awful that they barely needed that trick. The vertical shaft is not quite vertical. When switched off static friction is sufficient to keep it from rotating. When only the horizontal masses move their acceleration is sufficient to allow the device to rotate until the unbalanced mass is at the lowest point around the circle. It rotates far enough so we can see the far side of the arm which I suspect used hold a counter weight but was probably removed because the device moves more without it. If there were any 'curved space' magic here the device would be able to go all the way around. If there setup worked at all it should just vibrate without rotating when the vertical masses are stationary.
To "work" as intended the direction of motion should depend on the phase between the motions of the vertical and horizontal masses. By reversing the phase the motor can reverse direction to overcome some of the complaints normally levelled against fake reactionless drive demonstrations. The "magic" trick here is the vertical masses move on a curved track so they are nearer the bearing when at the ends of the track than when they are near the middle. They are only present to vary how imbalanced the setup is. When the vertical masses are in the middle friction in the bearing is greater than when the vertical masses are at the ends of there track. The horizontal masses then move the arm against low friction in one direction and against higher friction for the return trip.
I would like to say that as a fraudulent demonstration this one is utter crap but apparently they did manage to fool enough people to get reported here. Please, please tell me this is just click-bait and that no-one really fell for something so dumb.
[1] https://www.theregister.com/2018/05/23/emdrive_flunks_test/
Closer than you think...
With the nearest suspected black hole sitting over 3,000 light years from Earth, it'll be a while before we can test that.
The world is swarming with Black Holes - pick a government of your choice and look at their finances
Weird setup
Less jerky: Two weights spinning at end of the arm on its axis, with the two spinning synchronized in opposite directions to cause cyclical swinging of the arm. Two weights spinning on the axis of the arm close to its pivot, opposite of each other in the same direction so that they only change the angular momentum of the arm.
This needs three servos moving at a nearly constant speed, other than phase adjustment.
Not sure if it would prove anything, but it would have less noisy data..
It's just using friction.
Sit on a swivel office chair with your feet off the floor. Stick your arms out and slowly rotate them left then suddenly jerk them right, you'll spin slightly to the left on the chair. Repeat many times and you can turn yourself all the way around.
Watching the video it is obvious the robot is doing the same thing. This has nothing to do with curved space and everything to do with overcoming friction at slow vs fast speeds.
er ... doesn't the em-drive claim the same ?
was my immediate thought