Gravity Speakers

This video purports to show an amateur experiment in which someone created a small gravitational field "using a speaker and a generated sound wave." The instructions say that a Bose Companion 2 Series II speaker was used, and a "sine wave at 16 khz" was generated.

Obviously it's fake. Audio speakers will not create a gravity field. But I'm not sure how they created the special effect. (Not that I know much about creating video effects.)

Perhaps they used some kind of fancy editing software. Or perhaps they did it a really low-tech way -- moving the objects one frame at a time to make it appear as if they were sliding towards the speaker. If they did it the latter way, they managed to make the sliding effect look very smooth.

Perhaps it's a viral ad for Bose speakers.

For some reason this video keeps getting removed from Metacafe. Hopefully it'll stay up long enough for you to see it.


Posted on Wed Oct 24, 2007


Could just be a tilted table... he placed that glue awful carefully.
Posted by AThoms  on  Wed Oct 24, 2007  at  11:48 AM
My vote is for a magnet under the table. Every object was either partially metallic or it could have had a magnet attached to its bottom side.
Posted by Gomberg  in  Richmond  on  Wed Oct 24, 2007  at  12:13 PM
The big clue is the painting on the wall in the background. See how it gets more and more tilted as the demonstration progresses?

The whole "room" (table, wall, camera) is small and on a fixed but tiltable mount. When he's ready for the object to move, he simply lifts the "room" and the object slides down to the speaker, while from the camera's perspective everything stays level. Unfortunately for him, the frame isn't fixed tightly enough to the wall, so it shifts a little each time and blows the secret.

It's a little like that classic Fred Astaire scene where he's dancing on the walls, filmed in a rotating room.
Posted by Vincent  on  Wed Oct 24, 2007  at  12:21 PM
IMHO, a magnet underneath. Putting a ton of bb's into a white glue bottle is nothing new. It could be a tilting room, but I don't see the audio cable moving at all and doubt that the makers would think of that and not the picture.
Posted by OriginalSim  on  Wed Oct 24, 2007  at  12:30 PM
It's a tilting table/camera as Vincent states. Neat trick, but the background was kept too sparse to make it easier to pull off. He should have made a busier background to help hide the fact that it was a 'set' and not a real table and wall. The picture was included just to fool you into thinking it wasn't tilting, but even that he screwed up on. The pull-back was to make you think he wasn't tilting it, but the picture proves otherwise.
Posted by Charybdis  in  Hell  on  Wed Oct 24, 2007  at  12:42 PM
THe biggest clue that this is a hoax should be the fact that before each item "moves" the speaker volume is turned up, then turned down after each item. Why would this be necessary? If in fact a device is being used to create the sine wave, that device could be turned on and off regardless of the speaker volume. If the speaker volume is important to the movement, then the moment the object is placed in its path, it would move across the table. There is a significant lag between speaker adjustment and object movement. I vote for magnet under the table.
Posted by Tim  on  Wed Oct 24, 2007  at  01:18 PM
Posted by Nameless  in  London, marshmellow land  on  Wed Oct 24, 2007  at  03:02 PM
There's no 'snapping into place' typical of a magnet. Doesn't rule it out, but objects being moved by a magenet under a table move far more jerkily than this. They look just like they're sliding down an inclined table.
Posted by Charybdis  in  Hell  on  Wed Oct 24, 2007  at  03:31 PM
I really doubt they could "catch" the glue bottle and right the table in time to keep it from toppling.

If it were sliding into the speaker on an incline, it wouldn't "right" itself after bouncing off the speaker.

Plus, right after he lets go of the glue bottle it "jumps" onto the magnet. Just a slight movement to the right, but visible.

The cell phone strap would probably not 'stick' to the table on an incline, either.

The stapler jumps backwards as he lets go of it.

Posted by OriginalSim  on  Wed Oct 24, 2007  at  04:24 PM
Or, actually, it could be both, with the magnet just there to hold the item in place and then when the magnet is removed, the stuff slides down.

I'd still say that the glue would not bounce back - or perhaps they got lucky or did several shots to get it just right and confuse the issue.

Also, I see the picture tilting then back, then tilting, so I imagine they edited it out of the original sequence.

It's fun anyway!!!!
Posted by OriginalSim  on  Wed Oct 24, 2007  at  04:51 PM
And just to nitpick, that wasn't even 16kHz (like the sound of the cathode ray tube of a tv, or some crickets). Most adults can't hear that high, which would defy the purpose of using this sound.
The "Mosquito's buzz" is usually around 17kHz, but can go from 16kHz and up.
(See older post about the Mosquito: )
Posted by FrostBird  on  Wed Oct 24, 2007  at  04:58 PM
Update: I put it trough a frequency analyzer and I get a nice line at 400Hz.
16 thousand Hertz? HAH. tongue laugh
Posted by FrostBird  on  Wed Oct 24, 2007  at  05:18 PM
I think the entire field of view is tilted after the hand disappears. What you see is part of a static backdrop that is separate from the person....he is standing on solid ground outside of the tilt-able setup. The surface of the table must be fairly smooth and slick for easy movement.
Posted by Botfly  on  Wed Oct 24, 2007  at  06:36 PM
In the word(s) of Principal Skinner, magnets!
Posted by matteBlack  in  USA  on  Wed Oct 24, 2007  at  06:37 PM
I am fairly sure it is a tilted set, as many have described above. It is possible that it is set at an angle so slight that inirtia holds the objects in place (he places them very carefully) until some vibration (the speaker) is added. Since the piece is obviously edited, it would not be hard to try several times on each item until the best effect is achieved, such as "catching" the glue bottle. No magnet required.
Posted by Harry  on  Wed Oct 24, 2007  at  06:40 PM
the speaker isn't plugged into anything. you can see that in the last bunch of frames.
Posted by john  on  Wed Oct 24, 2007  at  06:55 PM
Hey, did anybody notice the speaker isn't plugged in to anythign?

On the pull away shot, pause it and you can see the other orange dongle of the cord on the floor.

Much less a power cable for the speaker, usually the one with the volume knob has the power cord... Don't know about this particular model though.

Picture for the lazy:

Posted by Stephen Ockham  in  Canada  on  Wed Oct 24, 2007  at  06:57 PM
Heh, John beat me to the punch while I was uploading the picture raspberry
Posted by Stephen Ockham  in  Canada  on  Wed Oct 24, 2007  at  06:58 PM
Definitely some moving of the set going on. Park your cursor on the bottom right corner of the picture on the wall when the video starts, and then watch it shift. It reveals some hard-to-spot cuts as well.
Posted by Shane  in  USA  on  Wed Oct 24, 2007  at  06:59 PM
Another interesting detail: Note what looks like a curtain screen set up to the right on the pullaway shot. Maybe to provide control over the light so no telltale shadows appear? Just an initial thought, but seems like a lot of trouble to go to unless there is trickery going on.

Enjoyable riddle here, though!
Posted by Shane  in  USA  on  Wed Oct 24, 2007  at  07:05 PM
certainly a magnet, the glue bottle is the giveaway , with the small jump that it makes when he sets it down.
Posted by Angstrom  on  Wed Oct 24, 2007  at  07:10 PM
Well, I took a look at the owners manual pdf, and yes, the power cable does connect with the speaker that has the volume/phones jack.

Funnily enough, the manual doesn't mention telepathy or anything else out of the ordinary.
Posted by Stephen Ockham  in  Canada  on  Wed Oct 24, 2007  at  07:17 PM
Here's a clue for you -look at the shadows around the picture frame and chair during the experiment and during the reveal pull back. They are at a steeper angle during the experiment suggesting the objects are propped at an angle relative to the (fixed)TILTED TABLE and camera. (also during the experiment the picture is held firm against the wall (at varying angles...) after it pulls away as if hung naturally from a hook.) Objects are held in place by a magnet held by the guys wife under the table. She releases the magnet and the objects slide down. The objects accelerate smoothly -so it has to be a force i.e. gravity. The lanyard on the phone is lighter so the friction of the table keeps it in place despite the tilt. Put a coffee table book at a 15-20 degree tilt and slide stuff down it -looks the same.
Posted by tickles  on  Wed Oct 24, 2007  at  07:53 PM
Does anyone know what the background music is?
Posted by James  on  Wed Oct 24, 2007  at  07:58 PM
magnet magic
Posted by sam  on  Wed Oct 24, 2007  at  08:15 PM
Looks like stop motion to me.
Posted by ollie  in  california  on  Wed Oct 24, 2007  at  09:05 PM
Ever consider this is TRUE gravity and the entire stage is being rotated while it pauses to allow the operator to place the object down when the entire table and camerage and stage are horizontal.

They did movie tricks this way in roaring 20's.
Posted by Tony (SunnySky) in WInterpeg  in  Winterpeg, MB canada  on  Wed Oct 24, 2007  at  09:05 PM
I think this effect could be obtained with a slightly tilted table, and a speaker set to play a tone that matches the natural resonant frequency of the tabletop.

Objects sitting on the table would be held in place by friction (and not slide) until the speaker is turned on at a frequency that causes the entire tabletop to vibrate. Once the vibration was established, the items on the table would tend to 'walk' down the slope.

The speaker itself could be kept stationary if it had rubber (shock absorbent) feet, which many of them do.

The objects would appear to move smooothly because they would be making tiny 'steps' at the same frequency as the vibration in the surface of the table.

In other words, what 'Harry' said.
Posted by Not Rocket Science  on  Wed Oct 24, 2007  at  09:19 PM
hahahahaha, very poorly done, watch the stapler
do the magnetic jump when he places it down and before he turns on the sound!
Posted by Rocky  in  Utah  on  Wed Oct 24, 2007  at  09:22 PM
Another interesting thing to note is that if there was some force attracting objects towards the speaker, wouldn't it have some impact on his hand when he turns the speaker on and off?
Just the first thing that jumped to mind. Kind of like putting your into the blender to turn it off...
Posted by Nathaniel  on  Wed Oct 24, 2007  at  09:35 PM
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