are star trek style holograms possible?
I mean an image that is projected into empty air.
is this possible? (not today, but with foreseeable improvements of current technology, like super computers 10 times as fast as current and such)
would some sort of light interferance work?
could you spit out atoms/molocules/something from either side of a room haveing them hit and light up at some point in the air?
is there any conceiveable plausable method for createing a hologram image?
The only experience I have is with developing flat holograms (oxymoron?), i.e. the type you hang on a wall. However, I don’t see Star Trek-esque holograms becoming a reality anytime in the foreseeable future. Conceivably, at some point in the future, anything is possible, but it doesn’t seem very likely.
The problem is, to produce a 3d image, you either have to create a fully 3d representation of that image, or create a 2d represention, wherein each pixel of the image contains massive amounts of visual information for all possible viewing angles. Conventional holograms use the latter means, but to create one out of thin air you would have to use the former, and that simply isn’t practical. Perhaps if you project hundreds of lasers into a fog and focus them all on very precise points, you could create a lame excuse for an image, but certainly not very easily.
Anyway, short answer no, not as far as I know. Sorry to dissapoint you 
I’ve got to disagree with hobbes730 on this one. I just saw a 3d desktop hologram display on slashdot.org today. Here’s the specs: http://www.actuality-systems.com/volumetric3d.php3
Okay, if you want to get nitpicky, it’s a volumetric display, not a holographic display. Hobbes is right in saying that a hologram can’t be projected into the air; it can only exist on a flat surface. But people have begun to use the word hologram to mean any 3-dimensional display. The holodecks on Star Trek aren’t really holograms, not is the guy on Quantum Leap. Neither is created by the laser-hlogram exposure technique which defines holograms. But that’s what everybody calls them.
So is it possible to create a 3d display that you can walk around and look at from all angles? Just follow the link. it’s already been done!
That’s true, certainly there are dozens of alternatives, such as the parabolic reflectors that produce 3d copies of pigs, coins, and such in “thin air”, but these are severely limited in viewing angle and suffer greatly from distortion. There are also volumetric displays as you describe, but these use special mediums such as a projector and rapidly-rotating screen to project the “holograms”.
Still, though, nothing comes close to living up to the specifications of the OP.
It’s easy once you implement synthequark projection.
Nah, wouldn’t work.
The synthequark projection would be countermanded by the Cojones effect which would raise the ion levels to such a point that they would de-fracterize the whole photon-belt.
It’s a crazy idea!
Wait a minute. If you micro-reverse the transfer rate of phase ante-proyection space while keeping a stable para-quark flow from a regularized nanoprism, it might just work.
I’d try it out myself, but my toaster is burnt.
How about this? Project RGB lasers from millions of points on a wall, in thousands of directions each. Each depicts what you would see if you looked in that direction at that time. IIRC, the holodeck is supposed to work something like that anyhow. And you did specify as much technology as I wanted.
Just make sure nobody walks between you and the wall, or everything between you disappears.
I like this idea better than ChaosGod’s, 'cause you don’t need to buy cubic meters of para-quarks at these outrageous prices.
One key element of star trek style holograms is that they use force fields to make all of the projected images seem real to the touch. The straight dope science advisory board doesn’t seem too keen on force fields:
http://www.straightdope.com/mailbag/mforcefield.html
Without the synthequarks, this is gonna be really hard to pull off. The key, of course, as any star trek geek knows, is finding the right modulation frequency. You don’t want to destabilize your dilithium crystals.
What makes you think the image has to be a bitmap?
G’day
Not only are holograms possible, but they have been practical for decades. I went to a display of holograms at the Museum of the Applied Arts and Sciences in Harris St in Sydney about 25 years ago. Several of the displays featured holograms that you could pass you hand through. One featured a real modern phone concealed by a superimposed image of an antique phone. You could reach into the image and pick up the handset.
As for computer-generated moving holograms, I’ve never seen one, but I read an article about a successful project to generate and project one in Scientific American at least ten years ago. It was small. It was monochrome. But is was a holographic image of the * Star Trek* USS Enterprise moving through empty space in front of the projector.
Regards
As someone correctly pointed out upthread, this is strictly speaking a volumetric display, not a hologram, because the image is not produced by holography. My apologies.
Regards,
Agback
Agback - I believe these are the volumetric displays that mcbiggins mentioned; you can ‘unfocus’ an image in such a way as to make your eyes ‘refocus’ it to appear in front of the screen, but what you can’t do is make it walk off the edge of the screen into thin air - you can only see the apparently solid object if you’re looking in such a way that it is ‘framed’ by the screen ‘behind’ it.
If there were some easy way to bend light (with electromagnets, for example), then air projected holograms would be possible.
Perhaps there is some way of ionising the air in a very small region in such a way as to make it behave like a mirror (setting up a miniature mirage), then bouncing a beam of light off it…
I’m confused…
I thought true holograms were produced by using a laser to illuminate something, then exposing that laser light to your film or whatever in combination with the original laser light. To view the hologram you shine the original laser light though the developed film, and a 3D image appears behind it.
I’ve never seen a proper hologram, just those you can view in normal light like the ones you get in cereal packets! Have i totally misunderstood this then?
The kind of ‘holograms’ that we’re talking about here is the kind they have in Star Trek (i.e. fictional ones) - images that appear to float in midair, that you can walk completely around and view from any angle.
Mangetout puts it succinctly and correctly. This is the difference between existing holograms and the “holograms” on Star Trek and other pop sci-fi shows.
I submit that we view the term “hologram” in these cases be viewed as a coverall term for all possible future 3-D technology, whether or not it’s really what we would call “holography”. It’s just the closest twentieth-twenty first century equivalent. Like the over-used “ray gun” (that became “laser” after 1960).
In order for the “million lasers on a wall” idea to work, you need a medium (other than another laser) for the photons to strike. That’s where Star Trek’s Magical Technology comes in… they just generate a force field, not only to make it solid to the touch, but to provide the interference necessary to make the end point of a photon’s path visible to the eye. In short, Star Trek’s holograms work pretty much the same way modern 3-D games generate their images… they have the blank “model” of an object, and then a “skin” that covers the model to give it color.
I have one of these. My dad bought it and had a little 1/2-inch pink plastic pig that he used as the object. It was fun seeing the expression on people’s faces when he told them to pick up the pig and their fingers passed right through it. I wouldn’t say that the viewing angle was severely limited; and the distortion only happened at the limits of the viewing angle. I thought the thing worked very well. I’ve seen these in catalogs and while they’re neat novelties, I wouldn’t pay fourty bucks for one. (I don’t think dad paid that much.)
Okay, strictly speaking it’s made up of hogels, not pixels, but most people know less about hogels than they do about synthe-quark projectors.
Of course the easiest way to do all this would simply be to use our replicators to produce a perfect replica of the object every time someone wanted to see it, thereby eliminating the need for a hologram at all. 
By the way, just a note: something can be a hologram or holographic, but there’s no such thing as a holograph. Unless you count the three-toed marsupial native to Zanarkin 5.