On Sunday 03 July 2011 00:51:29 Robert Heller wrote:
> > > There is (in the SciFi world) the idea that someday
> > > 'desktops' in the current / conventional sense may completely vanish
> > > from the universe, taken over progressably by laptops, tablets, smart
> > > phones, wearable computers (motherboard == shirt, monitor == shades,
> > > power supply == hat with embedded solar cells, virtual mouse/keyboard
> > > via motion sensors in your shirt sleves/gloves, etc.),
> >
> > I could in principle imagine all that coming in the future, but the
> > "monitor == shades" thing is just only Fi with no Sci in it. A human eye
> > cannot focus properly on any object which is closer to the eye than 10-15
> > cm (depending on the eye quality), so there is absolutely no way one can
> > use shades or contact lenses or something similar as a monitor,
> > regardless of technological levels of any human or alien races (James
> > Bond notwithstanding). Unless of course one surgically adapts the eye
> > lense itself, in which case the person would not be able to see anything
> > else... ;-)
>
> Hmmm... There were a CS prof. and some students at UMass when I was
> working there playing with a computer in a backpack with a 1" monitor
> suspended from a head mount in front of one eye. Not anything like
> 10-15 cm. If 10-15 cm is the minimum distance, what about telescope
> eyepieces, camera viewfinders (including the little video ones on
> camcorders), or binoculars? *I* know I can see images in the video
> viewfinder of my Sony Hi8 camcorder just fine, with my right up close
> (the old camcorder I have does NOT have a 3" swing out monitor). It is
> all about the optics.
I wouldn't know about that CS prof. at UMass. Have any info that can point me
to him? Other examples you mention all have to do with lenses that twist the
trajectory of light to make distant or small things visible. When using
telescopes, binoculars, camera viewfinders, microscopes, and other stuff like
that, you are actually looking *through* a (transparent) device to see
something else outside, you're never looking *at* a device, or something that
is inside it.
In contrast to that, actually drawing a picture which is 1-2cm away from the
eye is a completely different game. Just take a piece of paper, draw something
on it and put it 2 cm in front of your eye. The drawing will get blurred. And
it's not because you used a thick pen, but because the eye lens cannot focus
on such a short distance.
Now, you might consider putting some convenient lenses between the paper and
the eye, to fix that problem. I don't have time do actually do the calculation
of the properties of such a lens, but it's an interesting problem in geometric
optics. You would want a convex lens that moves the focal point of the eye
from 15 cm to 2 cm. The trick is to find a transparent material which would
have a refraction index high enough that it can do what you want, while still
be thin enough to fit between the monitor and the eye (ie. it needs to be
thinner than 2 cm). I don't know if ordinary glass or any other material would
do that or not. But it could be an interesting exercise for a student of
geometric optics. :-)
The bigger issue is the fact that, even if you manage to find an appropriate
lens to move the focal point to 2 cm, it is going to distort everything else
you see behind it. In principle you could devote one eye for the monitor-only,
making the whole apparatus non-transparent, and use the other eye for the
outside world. That would, however, destroy the 3D vision of both the outside
world and eventual monitor 3D picture (because you can wear it only on one
eye).
Actually, now that I think more and more about it, I am not so sure it is not
doable. However, it is far from being trivial, and it certainly cannot be
something that can be as thin as ordinary shades. It has to be bulky and heavy
(due to the optics inside) and is bound to impair your vision of the real
world.
If I get some free time, I might even try to calculate the properties of such
a system of lenses, but I'm skeptic that the cool "monitor-shades" will ever
be possible. ;-)
But now we are getting quite OT here... ;-)
Best, :-)
Marko
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