part 2
the boring mechanical nuts and bolts.

Starting with the room described in part 1 bellow, it would need to be enclosed in some sort of support structure. On the north and south sides of this, will be mounted bearings A & B the function of these bearings is to keep the room in the correct orientation, floor down, at all times. Bearings A & B are mounted on the travelling end of a short arms. These arms are mounted on bearings E & F, these arms are spun sufficiently fast to produce 2 G of centripetal acceleration.

Taking the situation as the room passes over the top, at the level of bearings A & B there will be 2 G of centripetal acceleration acting upwards and 1 G of gravitational acting downwards, leaving a net upwards accelerated of 1 G.

to complete the mechanical aspects of the design. The arms would need to be split in half, by bearings C & D. The outer part of the arms will be rotated about bearings C & D at the same speed as the inner part of the arms,along with bearings C & D, are rotating about bearings E & F.

Taking the situation as the room passes over the top, both halves of the arms will be pointing in the same direction, up. Half of a turn later the inner part of the arms will be pointing down. however the outer part of the arms will have turned trough half of a circle, and will now be pointing in the opposite direction to inner part of the arms.

So half a cycle after the top,where the rotary motion adds 2 G of acceleration, bearings A & E and B & F will be lined up. So at this point the only force is gravity. The path that will be traced by bearing A as it travels through one cycle will be an up side down rounded hart.

part 1
practice & principal.

This idea started life as a training aid for astronauts. But I think it will inevitably end up being hired out as a bouncy castle for adults. So that’s the idea, let NASA use it for dull work if they want.

Imagine 2 to 10 adults in a room that has; ceiling, floor and walls made out of strong trampolines The junctions between surfaces would need to be well padded to prevent injuries. The light would have to come in through the fabric of the trampolines

At the start the people would be clustered together, because the floor would be depressed in the middle. As the gravity is apparently turned off, they would seem to get lighter and the floor would level up. At some point someone would feel light enough to fly, and would jump up to the ceiling This would knock everyone else of their feet. They would over react instinctively, kicking themselves into the air. There will follow a period of adults bouncing of the walls like hyperactive 8 year old s Or trying to sit on the ceiling, not easy when people keep bouncing off it. Eventually someone would bump into someone, or grab someone, or find themselves in an interesting position, and the mood would change

The principal of operation.
No magic is allowed
Gravity acts downward with a force of one G, at all points, all of the time.

There are two states to the device.
A / Normal, gravity = 1 G down.
B / Driven = 2 G of upward acceleration minus 1 G of gravity down, = a net 1 G upward force.
By switching between these two states more rapidly than the body can be accelerated in either direction the illusion of weightlessness can be created.

[ edit / Ideally the arms should be kept as short as possible and spun fast. Large masses in high speed cyclical motion can cause problems. This dose not rule this out, as impossible, it just means that it would be difficult to do.]

If anyone can do calculus. How fast would the switching need to be to keep the movement down to less than an inch? I reckon it will be about 1/256 of a second. And that a frequency of 1 kHz will be about a 1/5 of an inch of motion. But my maths is fallible.
-- j paul, Aug 01 2011

State A: the device is at rest.
State B: the device is accelerated downwards at approx. 20ms^-2

If you alternate these states with equal time given to each, then the net effect is that the device is accelerated downwards at approx. 10ms^-2, i.e. it is in free fall.

So what advantage does all the vibrating have?
-- pocmloc, Aug 01 2011


//A / Normal, gravity = 1 G down. B / Driven = 2 G of upward acceleration minus 1 G of gravity down, = a net 1 G upward force.//

Upward acceleration produces the same feeling as gravity. Therefore this alternates between 1g down and 3g down.

If you meant the other way around, it alternates between 1g up (downward acceleration) and 3g down (upward recovery stroke). Net effect is still 1g down.

[Marked-For-Deletion] Bad Science
-- MechE, Aug 01 2011


//more rapidly than the body can be accelerated ... If anyone can do calculus.// Res ipsa loquitur.
-- mouseposture, Aug 01 2011


The astronauts in the US are standing in the unemployment line these days...
-- xandram, Aug 01 2011


//But my maths is fallible.// Rem acu tetigisti.

At best, the occupants will experience an illusion of weightlessness similar to that experienced by peas in a maraca. At least your OrGy won't need a separate vomitorium.
-- spidermother, Aug 01 2011


Are you sure you mean vomitorium?
-- nineteenthly, Aug 01 2011


I suppose, the idea is that the participants will never wish to leave all at the same time, since they are having such fun?
-- pocmloc, Aug 01 2011


I could have meant that there is no need for gladiators to come out and lay into everyone because there would be plenty of bloodshed and mayhem anyway, but instead meant a room to vomit in, because I just felt like being wrong for once.
-- spidermother, Aug 01 2011


// I just felt like being wrong for once //

We feel obliged to point out that that's not actually a precedent.
-- 8th of 7, Aug 01 2011


//that's not actually a precedent// Are you saying that I'm not going to feel like being wrong again? Or did you mean "that's not actually a first"?
-- spidermother, Aug 02 2011


You can't oscillate it at that speed - the stretch of the fabric will dampen it out, and the average will still be 1G.
-- Ling, Aug 02 2011


2 to 10 adults inside of a speaker, operating somewhere between 250-1000 hz, at something over 160 decibels?

The seismologists use the term "liquifaction". A mechanical engineer might say "pulverized", while a layman with a good blender might opt for "purée".

The attorney would simply term it "first degree murder". The defendant's barrister, however, would counter, "But it can't have been pre-meditated - it's obvious [j paul] never thought this through!"
-- lurch, Aug 02 2011


But would the resultant goo be suspended? Surely if the body bits were small enough, they would form a mist floating in the air and the dream of microgravity simulation would have been achieved?
-- nineteenthly, Aug 02 2011


Not my type of orgy. I don't think I would want to blend in.
-- Ling, Aug 02 2011


What if it were also evacuated?
-- nineteenthly, Aug 02 2011


[MechE] This isn't bad science. It's just a resonate trampoline driven by an oscillation of the floor rather than by legs. (With some implied sexual activity at random intervals.) The math goes badly wrong, however. The switching needs to be on the order of seconds, not milliseconds. Otherwise the occupants will be standing on the upper stroke position of the floor, and will have the unpleasant sensation of standing on a buzzing surface rather than floating. In which case the floor is accelerating up and down, but the occupant's body (except for the soles of his feet) is experiencing normal gravity. Vibrating feeders and hoppers work this way. They vibrate particles into a semi-levitated state, sometimes imparting a sideways motion to move them where they're wanted. The particles don't float off, however.
-- ldischler, Aug 02 2011


Vibrating feeders work this way, but they objects do not experience zero-gravity. The experience a repeating series of impacts that average out to one g downwards. If the frequency was just right, a standing person would, feel a series of 2-3g impacts on their feet with alternating brief periods of zero-g. Givent that it is specified to be fast, the rest of the body would experience a standard 1 g. (And flattened arches, broken bone, etc, etc.).
-- MechE, Aug 02 2011


[MechE] A bad science MFD is generally reserved for something really bad at the core of an idea, not something that doesn't work as advertised or has some terrible fault (like broken bones), otherwise, most everything on this site would have to be deleted.
-- ldischler, Aug 03 2011


This is intended to produce a zero g experience. It doesn't, because the basic concept is flawed. That's what gets the bad science mark. If the concept were valid but the excecution flawed, then I would agree with you. The whole broken bone thing is secondary.
-- MechE, Aug 03 2011


//but they objects do not experience zero-gravity//

In fact, they can experience free fall, but just for short periods. So there's no bad science, just bad engineering.
-- ldischler, Aug 04 2011


If the frequency is considerable lower than mentioned in the post, they will experience free fall for brief periods, but no different than jumping in the air. Given that this is supposed to be conceptually different than that...
-- MechE, Aug 04 2011


Let me start by thanking every one for some thoughtful and amusing annons I was afraid that you might not touch an idea in two parts. The reason for doing it that way was that I was hoping that some one would have come up with a better way of doing it. Because my idea of using an eccentric centrifugal force as serious short comings, not described above.

pocmloc
Not the floor dropping, but occupants being flung away from the centre of rotation.

MechE
Part of the reason for the two part submission was to try to separate my flawed design from the scientific possibility.
-2G + 1G + 1G =?G.
My design only manages this along the line between bearings A&B.

mouseposture
You know I have not mastered English yet, so I willn't have a chance if you are going to use Latin.

xandram
An other reason for not trying to sell the idea to NASA. I gather that the Indian space program is still flourishing. I wonder if there will be a brain drain?

spidermother
Of course it will need a vomitorium! People will need somewhere to take their shoes off before they are allowed on the trampolines.

On a more serious note. With the direction to the floor always being down, but with gravity apparently continually changing, in both direction and strength, someone is bound to ….........

I’m thinking more, Gladys ate her, than gladiator.

Ling
The soft walls are there so that I don’t have to use the defence that lurch as so amusingly layed out for my.

nineteenthly
unfortunately not. There will be a small //gravitational field down// to four of the six surfaces.

If it is evacuated, then that definitely excludes any sort of orgy.
-- j paul, Aug 08 2011


I would like to see a diagram. I'm still pretty sure this can't work on principle, but the mechanical description is unclear.
-- MechE, Aug 09 2011


// If it is evacuated, then that definitely excludes any sort of orgy. //

I don't think so. If we're thinking of genital contact between people, there just need to be suits with docking points and airlocks. The parties - actually i'll post this.
-- nineteenthly, Aug 09 2011


How do I post drawings.

What are the limitations on what can be posted?

Iv not seen any really clear drawings here yet, but then I am still fairly new to the HB.
-- j paul, Aug 09 2011


I’ve just reread the help file. To help people to visualize this.
1)
Start with bearing E, with rod 1 above it, pointing up. A curved arrow to indicate that rod 1 is turning clockwise. On the other end of rod 1 is bearing C, with rod 2 also pointing up, turning clockwise around it. And on the other end of rod 2 is bearing A. a small house symbol could be used to indicate the room, always the right way up. And most importantly an arrow leaving bearing A pointing away from bearing E. this indicates the scale of the centrifugal / centripetal force throwing things away from bearing E. For the sake of this image make it 4 units long. 2 rod lengths from E and 2 units of rotation about E.
2)
Moving on a quarter of a revolution Rod 1 is horizontal and to the right of E. Rod 2 points vertical down. The house symbol should still be right way up, but the arrow pointing away from E will have shrunk to 2.4, 1 unit of rotation around E and 1.4 units distance from E.
3)
A quarter of a revaluation later, bearings A & E are in line with each other, so there is no force being generated by the rotary motion.
-- j paul, Aug 09 2011


A different way to visualize this, that might make it more obvious / intuitive.

Imagine standing on the edge of a childes roundabout, in a play ground whilst it is being spun really fast. It will feel to you like you are being thrown out over. Note that is not a feeling of being pushed out, but more of a feeling of falling / flying out.

Now imagine an identical roundabout mounted on top of the first one, with its centre at the edge where you had previously been stood. Standing on the edge of this one as it goes round, you will move between standing over the top of the centre of the first roundabout, and a position two roundabout radii from that centre.

As seen by someone on the climbing frame, with both roundabouts turning clockwise at the same speed.
as you are moving out to the point furthest out, both motions will be moving you in the same direction, left to right. The distance between you and the centre of rotation is long and as a result the outward force that you feel will be large.
half a revaluation later, the first roundabout is now moving right to left, but the second one is still moving you left to right. The result is that you are moving much slower as well as being closer to the point about which the roundabouts revolve relative to the playground. So you feel less force.

If you have got this image, turn it on its side so that the maximum force is strait up and twice as large as gravity.
-- j paul, May 14 2012


or a giant hamster wheel.
-- FlyingToaster, May 14 2012


[marked-for-deletion]

You completely replaced the original idea with a different one. That makes the annos totally irrelevant. If you want to do that, delete the entire idea and start over, don't hijack everybody's stuff and make them look foolish.
-- lurch, May 14 2012


The shape produced is a cardioid. The equation is r(theta)=1-sin(theta). I don't deny it will produce a brief free fall as the person falls towards the origin. It will then produce a very rapid shift to a 2g force back out. Net result, the person still experiences an average of 1g.

Per the earlier discussion, if this is fast enough, the person might only feel the average 1g, but most likely will end up with shattered feet.
-- MechE, May 15 2012


I've read this all again, very carefully, including the new material, and...

It's not so much that I don't get it, but that I find myself wondering what's there to be got.
-- Alterother, May 15 2012


Would these be, er, nekkid people? Hence the name?
-- Ander, Apr 12 2016


This reminds me of a technology for growing bacteria in effective zero gravity, without having to leave the ground. It's a device that repeatedly bounces the bacterial culture up into the air, so it spends most of its time in freefall. The acceleration of the bounce is too short for the bacteria to feel it. Obviously this would not work in your application.
-- notexactly, Apr 13 2016



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