62 years ago on May 15, Nature (a scientific journal) publishes the landmark paper of Dennis Gabor. It started the field of Holography.
On May 10, 2010 the Philippine media via GMA 7 and perhaps ABS-CBN taught an entire nation what a hologram is. The thing is, their hologram is not a hologram.
It has been 3 months since the issue of hologram erupted in Philippine media. It took me time to write about it not only because this blog is new BUT because I want to wait for emotions to settle. Science will never (and never intends to) win in any popular contest.
I will write as a reponse to a post of GMA7 in its facebook page. I think I also made a hasty reply to that page but here is the more detailed response.
I guess who ever wrote that post hasn’t read his references well. If he did, he will not be able to miss this in his 1st reference : Note that the process is referred to as holography while the plate or film itself is referred to as a hologram. The Nobel lecture (the post’s 2nd reference) of Gabor clearly has a picture of what a hologram is. It can’t be missed. His landmark Nature paper (May 15, 1948, pp 777) has a picture of a hologram also.
The GMA7 images are not holograms as much as CNN’s from the basic definition above. To pass it off as hologram is deceiving but to make that post in particular is a blatant twisting of scientific facts to cover up the deceit. It seems to me that that post only gets the facts the writer wanted. The note says it wants to clarify the matter as though it is an authority but skips out the science which really matters. This scares me because it comes from a news organization.
A hologram is a recorded phase of a wave (frozen record of the character of the wave). The character of a wavefront is recorded in a medium and the wavefront is reconstructed by placing an incident wave on it. With specific parameters for the incident wave, the wavefront will appear as if it has the same history as was recorded, even though the object that is responsible for that wavefront is not there. Confusing? Let’s just say the hologram is that thing in the material including the material. It is NOT the image that is seen. The image is called a reconstructed image or reconstructed wavefront.
It is true that a hologram can be made without coherent light because any body can record the phase of a wave. In can be calculated then recorded or encoded. Reconstruction of the wavefront can also be done either in the physical space or the virtual space (the computer).
The scratch hologram the post is referring in ref 4 is a hologram because the scratches are specifically made in such a way that it will be able to diffract light. The scratches mimic the record of the phase of light. The image produced by the scratch hologram is not the hologram. The hologram is the scratches plus the film.
So what is it that they broadcast?
It is a tomogram.
Let’s look at a video from GMA7’s election coverage. Did anybody see anything fancy in 02:53? Why didn’t the camera staff block ‘hologram’ Noynoy? If he is shot and placed in the studio via ‘holographic projection’, the camera should see Noynoy at the studio and not placed in (on) the camera. The light that we see comes from the object that reflected/ scattered that light. That is the reason why we see an object. If ‘hologram’ Noynoy was there, the light that was scattered from him will be blocked by the cameraman. Proof that GMA7 did NOT use ‘holographic projection’.
CNN made a blunder by saying that they have a hologram which by definition is also not a hologram. What is nice about the CNN’s image (it was ugly, btw), is that the camera in the studio are synchronized with the camera in Yellin’s tent. It is more similar to tomography where a 3D image is spliced with as many 2D images. GMA7 said they used the same technology, but was there a tomogram? I also doubt that Yellin’s light was there at the CNN studio.
Did GMA7 and CNN lie when they used the word “hologram”? The answer is No but…the concept they broadcast is wrong.
They could have said ‘similar to tomography’ but they insisted in using the term hologram. They could have educated people more by calling it what it is than trying to be ‘cool’ and ‘sexy’.
This to me is never about SEMANTIC. When scientists talk about scientific words, they are very careful because a whole lot of science depends on it. By saying that it is a SEMANTIC debate, Science is trivialized as only a bunch of facts. It disregarded that it is a web of consistent logic tested with experiments, which tries to explain the beauty of the Universe.
My only agenda in this issue is science education and science information dissemination. What GMA7 did is science pollution. I have seen too many people with so much ‘misconceptions’ ingrained in them. What GMA7 did is to reinforce some of these misconceptions namely, on what a hologram is, on how 3D is perceived, and on how we’re able to see.
A teacher’s job doubles because of misconceptions.
By the way, GMA7 already stopped using the term hologram after the damage was done with no plans of rectification.