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  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. 😛
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  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  on  Wed Oct 24, 2007  at  06:57 PM
Heh, John beat me to the punch while I was uploading the picture 😛
Posted by Stephen Ockham  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  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  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  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  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  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  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
Note that when the cell phone is being pulled by the "gravity," the nylon lanyard doesn't move at the same speed as the phone - it gets dragged alongside. If the phone was being pulled by "gravity," the lanyard would move along at the same speed.
Posted by Adam Stanhope  on  Wed Oct 24, 2007  at  09:39 PM
i'm a recording technology major at the university of memphis (with very little time right now) but my first thought was that 16khz is the resonant frequency of the table which would cause for some serious vibrations visible or not that could very easily move objects across a slightly slanted smooth surface. just my two cents. peace.
Posted by Mickey  on  Wed Oct 24, 2007  at  09:47 PM
Both the magnet/tilting sound like plausible explanations. I don't really have an opinion on how it was done.

However, it looks awefully like a viral to me. It begins with a nice shot of the brand name before the video. There is a nicely set camera angle with a shot of the hand turning on the camera before each test. It is decently lit (for a "home video"). Then, right before the end, we see an intertitle slide reminding us of the Speakers. Finally, we get an unnecessary pullback shot, enough to reaffirm it was a "home video" to the viewer. Especially in a video otherwise so well edited, it seems completely out of place.

Viral videos seem to often try to remind us that they are home videos in an attempt to make them seem legitimate. It seems to be the general concensus that this has at least some video tricks employed. It seems like a lot to go through for such little return. I mean, what other motive would someone have for making a fake video about their speakers.

I'm certainly not ruling out that it is real (in the sense that it was one unaffiliated person that made the video). However, it seems to contain a lot of the classic elements of a viral.
Posted by Archibold  on  Wed Oct 24, 2007  at  09:51 PM
wow thats awesome! i have to buy some bose speakers....
Posted by kevin  on  Wed Oct 24, 2007  at  10:41 PM
Alex, speakers do generate a gravity field, any object with mass does. However, the mass of the speaker is so slight compared to anything else that it is swamped by the Earth's gravity field. But this trick seems done by magnets, or tilting or some compination of the two. And maybe the frequency of the sine wave is the resonent frequency of the table, which would help by vibrating the table, but I doubt it. The resonent frequency is determined by size primarily and I think the table is so large that the resonent frequency would be sub-sonic or deep into the bass frequencies. Just an idea.
Posted by Christopher Cole  on  Wed Oct 24, 2007  at  10:46 PM
That's idiotic. The camera is attached to the table. The table is tilted so that the left side is higher. The chair and wall picture in the bankground are tilted too. The objects have enough frictional force to stay still until the speaker cases the tabletop to vibrate, and then the objects fall downwards to the right. Look how the cable on the back of the speaker is hanging.
Posted by martin  on  Thu Oct 25, 2007  at  12:13 AM
I vote for the tilting room effect.
Not only did I notice that the picture on the all kept moving from shot to shot, but it seemed weirdly placed - too low to be realistic, yet low enough to be in the shot to give realism to the background.
I think a magnet would make the objects jump or jerk before being moved.
Posted by rich  on  Thu Oct 25, 2007  at  12:45 AM
If the speaker had actually been plugged into something, then I would have said that the table was tilted at a slight incline, say <10 degrees. When the speaker gets turned up it would cause things on the table to bounce very slightly, and "jitter" down the table.

But, no.
Posted by derWiskinator  on  Thu Oct 25, 2007  at  12:50 AM
There's some kind of tilting going on; the back wall and the table are not attached to each other! The picture's frame tilts in an arc between takes, with the center of rotation just to the right of the top corner of the chair. If you place a ruler along the bottom edge of the picture frame, you can mark where the extended lines from the different frame angles intersect (I used post-it notes so as not to mark up my monitor). That would be your center of rotation.
Posted by MrGlowbug  on  Thu Oct 25, 2007  at  01:23 AM
I doubt it's a tilting table, unless all the lighting in the room is also tilting with the table.

Maybe the speaker is an electromagnet.
Posted by Chris  on  Thu Oct 25, 2007  at  02:59 AM
My guess, the table is slightly tilted such that the friction between the objects and the surface (just) keeps them in place. the vibrations of the speaker perturb it just enough that the object begins to slide, once it is sliding it just keeps going. The fact that the objects seem to accelerate as they slide hints that a slope it involved.
Posted by Martin  on  Thu Oct 25, 2007  at  04:35 AM
Not only does the table change angle relative to the picture frame between cuts, but the cable coming off the back of the speaker changes angle relative to the speaker.
Posted by Wesley  on  Thu Oct 25, 2007  at  05:00 AM
Vincent is right.

Let the movie load, and then scrub through fast from beginning to end. The picture on the wall behind is getting rotated round a little more each time.

Therefore, I think the whole room is a set (including fake floor), the camera and probably lights are also attached, and everything tilts, so that the items just slide downhill towards the speaker. They are always placed very carefully so that they will slide in a line and "land" on the front of the speaker. If they'd been to the side just a little, they would have fallen past the speaker, and the game would be up.
Posted by pad  on  Thu Oct 25, 2007  at  05:26 AM
My thought is that the speaker is working, and that the tone (clearly not 16K, though 16K is in the normal hearing range, albeit at the top) is vibrating the table via resonance of either the tone or one of its harmonics.

If you've ever seen the footage of the Tacoma-Narrows bridge heaving back and forth before crashing to the water below, then you know how powerful resonance can be. The bridge collapse was caused by the wind vibrating the bridge causing it to oscillate at one of it's natural frequencies.

As noted by FrostBird, I get a frequency of a G above middle C on a piano keyboard, right at 400hz.

If the table was leaning even a little, it would vibrate itself downward.

There is no magic, and no voodoo. And certainly has nothing to do with magnets. Sorry, but Elmer's is just not magnetic. I don't know for sure, but I wouldn't be surprised if it isn't even slightly diamagnetic (and you would need extrodinary magnets to physically test this).

For the claim that no other speaker would do this, it could be something as simple as rubber feet on the bottom of the other speakers damping the vibrations. How many speakers did he test?
Posted by royce  on  Thu Oct 25, 2007  at  06:26 AM
I think it's magic.
Posted by Web  on  Thu Oct 25, 2007  at  07:04 AM
I think that movement is too smooth and too closely matches the acceleration of something sliding down a slope for this to be magnets.

One important note is that there is a cut immediately before the pull-away! This means that the whole setup might have been made in a smaller tiltable model, and then the pieces moved into a room to 'prove as genuine'.

Plus, as others have mentioned, the speaker is clearly not plugged in, so it's faking even at the basic level.
Posted by Rob  on  Thu Oct 25, 2007  at  07:26 AM
Definitely a tilted table thing. The things about to slide are put down carefully, because they're held there with a magnet. When the speaker is "turned on" the magnet underneath is pulled off (or switched off) so that the item can slide down the table.

Biggest giveaway for me - the cut from the end of the last experiment. You see the slide, then a title card, and then a pullaway - not in one shot. And if you look carefully at the picture at the end of the last experiment and the beginning of the pullaway, you can see that it suddenly gains a shadow - because it's not stuck firm to the wall any more.
Posted by Steve  on  Thu Oct 25, 2007  at  07:31 AM
At 102 seconds, take a look at the speaker wire end on the floor. It's not even plugged into anything.

Posted by hoaxfinderouter  on  Thu Oct 25, 2007  at  08:30 AM

monofilament, object placed on monofilament and pulled.

When pulled, same effect.

Notice how glue bottle slides as being put down.
Posted by JGB  on  Thu Oct 25, 2007  at  10:43 AM
A magnet under the table, dragged along and pulling the object.
Posted by Craig  on  Thu Oct 25, 2007  at  12:18 PM
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