Hologram project advice

bogwalrus

I would like to suspend a 3D holographic image of the earth in mid air using relatively simple means (ambitious I know).

I would like some advice on how I might go about this.

My research has given me a few ideas that maybe you can look at and help me evolve or scrap.


My main idea is to find a gas that can easily be projected on. If none can be found then find a gas that can be manipulated to allow light to be projected on it.

My understanding of light and photons is that light is absorbed and released by an electron surrounding the nucleus of an atom. The reason why light reflects so well off a mirror is because a mirror is pretty much a wall of electrons. So what I want to do is create a large number of free roaming electrons in a particular area in the air.

I have been looking into magnetic fields and found that Oxygen is a ferromagnetic gas. Maybe using magnets I could suspend some sort of gas (oxygen) in a particular area, manipulate the gas in some way creating more free roaming electrons and then projecting an image on the gas?

Is it possible to ionize a gas in a safe way to create more electrons and then have these extra electrons interact with photons of light from the projected image?

Is there a way of exciting a gas using hypersonic (ultrasound) speakers that might allow an image to be projected on the gas. In many ways causing the gas to vibrate so photons can interact?

You can buy fairly cheap and simple ionizers, hypersonic speakers on the net these days so the technology is available for me to get if it might do the job.

The hypersonic speakers are interesting as they have some unique properties.

I have a few other thoughts that are not fully researched like using curved mirrors and all sorts of lenses and weird materials but I don't think anything would be a cool as using a gas that can be projected on.

Just to give you a visual of what's in my head.

A square podium 1ft x 1ft and 4ft high with the earth rotating about 6 inches above. The projection could be from above or below and maybe a few mirrors used on the sides to help the light complete a whole globe.

citrus burst

I propose this dowackey:

mirascope

bogwalrus

Made one of those bad boys when I was 13. Took apart two large torches and placed the semi spheres on top of each other. My teacher thought I was a genius but I actually read about it in a book in the library.:D


There is a company that make spherical lcd screens for Google earth. They are the size of an apple.


Might be possible to put sphere inside a mirror chamber like above and have light projected from inside the sphere.

Not as scientific though=(

Lbeard

bogwalrus wrote: »

My understanding of light and photons is that light is absorbed and released by an electron surrounding the nucleus of an atom. The reason why light reflects so well off a mirror is because a mirror is pretty much a wall of electrons. So what I want to do is create a large number of free roaming electrons in a particular area in the air.

Reflection from a mirror is one thing. Reflection from everything else is something else. Essentially you can only see something if it's either reflecting or emitting light. What you're seeing in terms of reflections, say if you look at grass in a field, or the colour and texture of concrete, it's a lot more than just the principle of reflection by a mirror.

What you have in mind, if it was that simple, Samsung would be making 3d tvs and there would one in every home.

I would like to suspend a 3D holographic image of the earth in mid air using relatively simple means (ambitious I know).

This is easier than you think, and should be well within your abilities - just if you're going to show this off to people, hocus pocus them.

You're eyes see everything in 2D.....You're brain plays tricks then to give you the illusion that what you're seeing is in 3D. With a little trickery you can convince people what they're seeing is a 3D hologram when it isn't.

Tupac Shakur's live festival appearances of late, although the promoters claimed these were holograms, of the late Tupac. They weren't. It was the same simple mirror trick that has been used by stage spiritualists since the invention of glass. It's not a silver back mirror, it's a sheet of glass turned at an angle (maybe 45 degrees) - so if you look directly at the stage, you can't see the glass, but from side stage they can project a video onto the glass, and that will be reflected. But you do have to set the stage so nothing gives the trick away.

The stage mirror trick, when done properly, never gets old. I've heard of it being used in stage plays in Dublin, and it scaring the bejayus out of people.

bogwalrus

There are some great examples of the stage mirror tricks being done on small scale. Looks really good but the glass is easily visible so I was kind of turned off.


I'm not looking to create a hi-res image but just some sort of image that can pass off as the earth.



I have been looking more into finding a heavy gas that could be suspended in the air and possibly compressed to allow for an image to be projected.


I have been reading about resonance and thinking maybe an answer lies here.

Can a gas resonate and if it can what actually happens?

I found this piece here about Nitrogen resonance:

We observed the thermal phonon resonance of nitrogen gas with optical-beating Brillouin scattering and measured the sound velocity and the absorption coefficient in the MHz region. Optical-beating spectroscopy possesses a frequency resolution of 1 kHz, which enabled us to resolve the fine structure of the thermal phonon resonance spectra. Resonance peaks of phonons were observed at every 185 kHz in the resonance cavity composed of two flat glass plates. The measurement accuracy of the sound velocity and the absorption coefficient was remarkably improved to 10−4 and 10−1, respectively.
© 2008 The American Physical Society



If a gas can resonate then each particle should cover more space in that area no? Similar to the way you can project light on to a rotating fan to see a complete image I am wondering if that could apply here with a gas.

Also maybe the frequency of the projected image could be matched to the resonant frequency of the gas. This might be the key to an image forming.

Lbeard

bogwalrus wrote: »

There are some great examples of the stage mirror tricks being done on small scale. Looks really good but the glass is easily visible so I was kind of turned off.

The trick to it, is controlling the lighting of the environment. When it's done properly the glass is completely invisible to the audience - if you've seen the holograph performances with dead rappers, you'll notice the stage is completely dressed in black,

I'm not looking to create a hi-res image but just some sort of image that can pass off as the earth.

I have been looking more into finding a heavy gas that could be suspended in the air and possibly compressed to allow for an image to be projected.

I have seen the trick where a moving image is projected onto a stream of steam vapour.

I have been reading about resonance and thinking maybe an answer lies here.

Can a gas resonate and if it can what actually happens?

Okay, now things get really complicated. The individual atoms do resonate - in that at certain frequencies their electrons will jump to a higher energy level. And then they release that energy as light. there isn't any way to control in what direction the light is emitted. If you shine a light through a gas, and measure the what's being absorbed at the other side you'll see lines missing - those are the line spectra. The missing light is not still in the gas, it's just left at directions that aren't in a straight line - so you might get the mistaken idea the light has been permanently absorbed.

I found this piece here about Nitrogen resonance:

We observed the thermal phonon resonance of nitrogen gas with optical-beating Brillouin scattering and measured the sound velocity and the absorption coefficient in the MHz region. Optical-beating spectroscopy possesses a frequency resolution of 1 kHz, which enabled us to resolve the fine structure of the thermal phonon resonance spectra. Resonance peaks of phonons were observed at every 185 kHz in the resonance cavity composed of two flat glass plates. The measurement accuracy of the sound velocity and the absorption coefficient was remarkably improved to 10−4 and 10−1, respectively.
© 2008 The American Physical Society

This is something else. It's a very specialised area of physics. If I've figured out what they're doing there correctly, They're using sound waves to resonate a cavity with nitrogen gas in it. At frequencies where the wavelength is equal to an integer value of some dimension of the cavity, (this is where you get standing waves) they're seeing a peak in the spectra, light emitted from the cavity. This light is caused by intra-atomic collisions. The thing is, if you plug a guitar into a loud amp and play it, the air will release light in response to your playing, but it's not going to be in a visible range. I've never seen anyone try to capture it on camera - if that can be done - I imagine it looks like fluctuations in the intensity of a broad spectrum, related to the frequencies in the music. It's not something I would image you could make images with.

If a gas can resonate then each particle should cover more space in that area no?

If the phonon is large then, the shape of the phonon is made up of the net momentum of the individual particles. They movement is very chaotic and there are trillions of particles in a large phonon.

Also maybe the frequency of the projected image could be matched to the resonant frequency of the gas. This might be the key to an image forming.

There's another kind of phonon. And that is the optical phonon - or it's some times called the opton . Essentially, if you pass a mechanical pulse through a crystal, of a high enough frequency, you will get a photon (light) of that frequency emerging elsewhere.

Particles, and especially light are not easy to work with at a small scale. The quantum phenomena become more pronounced. (just playing around with an idea in my head that I have not thought out - but maybe it will be possible at some point to generate real holograms in air, using optical phonons. but not something I would imagine to be easy by any stretch)

bogwalrus

Cheers for the replies Lbeard. I tried replying twice already and had a brain fart both times.


I was going to ask about gases like Xenon and Krypton that are commonly used in lighting. Both heavy gases and inert so technically harmless to breath.


The same way you can project on water vapour would it ever be possible to project on any heavy gas even if you found a way to clump a load of it together? Is the size difference between water vapour and a heavy gas like Xenon just really big?

I think Xenons frequency is in the blue spectrum so if white light interacts it will only absorb and reflect blue light. Is this correct? If so then I take it that it is just impossible for light to interact fully with any single gas particle. (as in a gas cloud of one type of gas will not be able to absorb and release any other colour?

So if i covered a wall in Xenon atoms and projected a load of colours I would see only blue or would I see every colour except blue?

Lbeard

bogwalrus wrote: »

I was going to ask about gases like Xenon and Krypton that are commonly used in lighting. Both heavy gases and inert so technically harmless to breath.


The same way you can project on water vapour would it ever be possible to project on any heavy gas even if you found a way to clump a load of it together? Is the size difference between water vapour and a heavy gas like Xenon just really big?

When water vapour is very hot, it's transparent. You see right through it. it's only when it's condensing as steam can you see it. Water molecules are very tiny, but the micro droplets in steam are not. It's to do with the way the light is scattered and reflected by the water droplets.

I think Xenons frequency is in the blue spectrum so if white light interacts it will only absorb and reflect blue light. Is this correct? If so then I take it that it is just impossible for light to interact fully with any single gas particle. (as in a gas cloud of one type of gas will not be able to absorb and release any other colour?

No. There's several different optical effects. Spectral lines is just one - that's the specific colour emission and absorption. With projections the image you're looking for is a reflection of light. Something like a cinema screen, it's white surface, or even if you were to use steam jets to project onto, it doesn't really work like a silver backed mirror, and spectral frequencies of the material are not that important. It more scatters back the light that reflects it - with a silver backed mirror, the image in the mirror changes depending on where you are standing in the room. With a cinema screen you see the same image no matter where you're in the room. When you scatter, the angle of incidence is not equal to the angle of reflection.

So if i covered a wall in Xenon atoms and projected a load of colours I would see only blue or would I see every colour except blue?

If it's condensing like steam, then you'll see an image, but it's very hard to condense - water vapour is much easier.

bduffy

My 2 cents: I think you're going to have a great deal of difficulty here as you won't be able to contain the gases you're considering. The gas will simply not stay, unless you flood your room which may defeat the purpose. If you were to then introduce gas from a source (such as a canister) to create a steady state system, then the flow of gas would blur any reflected/emitted light.

Just an opinion....

bogwalrus

It seems to be a tricky one alright. I projected a laser pen through a xenon bulb and did notice the laser getting more fuzzy in the gas. Unless I can compress this gas then I really don't think an image can even form on a heavier gas without some other alteration like freezing, resonating the particles or maybe ionization.

Another concern is that a heavy gas particle when interacting with light just does not react in a way that allows an image to be visible.

I still think however that there must be a way to project an image on air. It will probably have to involve a serious amount of tech and science so for now I think this myth is busted.