Idle Diffractions

When Will Virtual be Reality?

A futuristic-looking Head Mounted Projection Display (yes, it really does work).
Image courtesy of ODALab, Prof. Jannick Rolland.

This week I attended the International Symposium on Mixed and Augmented Reality (ISMAR) conference in Orlando.  This is an annual conference that circles the globe every three years, from the U.S. to Asia to Europe.  Next year it will be held in Seoul.  It started life as an IEEE workshop in 1998, maturing to a full conference in 2002.  In a year when any other conference I’ve been to was down 30% in attendance, ISMAR’s attendance doubled to 400, about the size of the upcoming International Optics Design Conference (IODC 2010) in Jackson Hole, WY in early June (couldn’t pass up the opportunity to plug IODC).

This year for the first time ISMAR attempted, with some success, to mix science and art.  Nearly one-third of the conference agenda was led by educators, performers, and authors.  While in general each group stayed on their own side of the hall, every now and then someone would find themselves in the “wrong” session.  In my case, this happened yesterday.  The speaker, a poet, was running down some recent works developed for augmented reality. Who knew? I found it to be a fascinating topic, well outside of my box.  In most cases, these are video format pieces that are meant to be experienced with a head-worn display (HWD), the latest terminology for this technology.  Which of course does not happen to exist, and therefore this art form is currently experienced though the screen of an iPod.  This is almost embarrassing to those of us who have been working diligently for over a decade to bring a personal HWD to a store near you.  In the piece that is the easiest to describe, the “artist” introduces you to “video archeology.”  You are given a map, a video, and an iPod customized to know where it is via GPS.  As you pass over key points on the map, the iPod displays video content created earlier, elsewhere, of events that took place at a location going back in time.  I found this to be a very exciting concept.  There were a number of other pieces that were more abstract, but nonetheless begin to show how transformational augmented and virtual reality is likely to be.

It was somewhat by coincidence that the talk I gave at the OSA Annual Meeting the week before, in San Jose, was on the technology of head-worn displays.  Coauthored with my wife, Prof. Jannick Rolland of the Institute of Optics at the University of Rochester (and formerly of CREOL), this paper reviewed some current technologies that are being pursued to result in a viable personal display.  The presentation used at both OSA and at a workshop at ISMAR can be downloaded here.*  In addition, there is an excellent overview article on personal displays in particular, authored by Dr. Ozan Cakmakci, the most recent addition to ORA’s Engineering Services Group, and Prof. Rolland, his advisor, in the April 2009 issue of Optics and Photonics News.

* I wasn’t on the ISMAR agenda, but since I had the material I sat in on a panel. It probably didn’t hurt that Prof. Rolland was the conference co-chair.

Ozan Cakmakci, who recently joined ORA’s Optical Engineering Group, sporting the latest in augmented reality eyewear. Image courtesy of ODALab, Prof. Jannick Rolland.

The look of the current generation of prototype see-through displays,
clockwise from the upper left: Lumus, Sony, ODALab, ORA.

Interesting Links

• International Symposium on Mixed and Augmented Reality 2009: http://www.ismar09.org/
• Optical Diagnostics & Applications Laboratory (ODALab): http://www.odalab-spectrum.org/
• OSA presentation, “The Coming Generation of Head-Worn Displays (HWDs): Will the Future Come to Us through New Eyes?”

Notes from a visit to the Large Binocular Telescope

 

Last weekend I had the pleasure of taking an “insider’s” tour of the Large Binocular Telescope (LBT), currently the largest telescope in the world based on baseline (22M) and I believe collecting aperture (although it’s hard to keep track), at 2X8.2M.  It was a very nice afternoon and the trees at the peak (10,200’) had turned a brilliant fall yellow.

Since one of my first experiences in optics was to star test one of the last of the six original mirrors in the Multiple Mirror Telescope (MMT) on Mt. Hopkins south of Tucson, it was quite a reset to view how massive the LBT building is compared to the original MMT building, which can be seen from the LBT.  At one point we trekked all the way to the roof (OK, a lot of the trek involved a series of elevators), which is over 200 feet off the ground, to an unseen tiny cement escarpment that provides an amazing view back to Tucson and beyond.  In that we are recently applying nodal aberration theory to these telescopes, it is an interesting perspective to look at an 8.2M mirror and then contemplate the question, what does a 10-micron decenter actually mean?  With these mirrors, there is no absolutely smooth edge circular aperture to measure from.  These are spin-cast mirrors made at Roger Angel’s lab in Tucson and as such the edge is good, but is not a micron-level reference surface.  The experience reminds me of when I worked on an Air Force conformal optics project.  We kept asking for the wing profiles to a number like 10 microns.  The Air Force finally decided the best response was to put us on a plane to St. Louis, where we learned airplanes are made pretty much the same way as a Grumman canoe, containing over three miles of wire.  They do not work well as an optical reference surface.

Additional LBT informational websites are shown below:
http://medusa.as.arizona.edu/lbto/
http://en.wikipedia.org/wiki/Large_Binocular_Telescope
http://www.aip.de/groups/lbt/
http://planetquest.jpl.nasa.gov/lbti/lbti_index.cfm (very short)
 
YouTube video:
http://www.youtube.com/watch?v=rtOyCcJtzcw

I came across a website titled, “100 Hours of Astronomy,” which was created in the spring of this year as part of the global celebration of the 400th anniversary of the first use of an astronomical telescope. I did not spend much time there, but it appears to be a tremendous series of on-site interviews with astronomers at telescopes around the world. I look forward to taking some time to explore the website – enjoy!

100 Hours of Astronomy main page:
http://www.100hoursofastronomy.org/

New Evidence on the Dates of the Oldest Telescopes

Over the weekend I received several books on the history of telescopes from a number of sources, including my ”favourite” source -- the Royal Society.  The books included Charles King’s excellent “History of the Telescope” from 1955 ($75).  If anyone is interested in a copy, there was a second copy available, although it may well be gone by now.   This small collection will form the basis for my current project, creating a list of the observatories of the world -- with two goals.  First, to find how many have primary mirrors that are over about 30" in diameter and are constructed before 1970-1980 (and therefore are likely to suffer from binodal astigmatism).  The second goal is to determine if the database contains enough information to create an optical model of at least the main telescope.  Three of the books have lists of observatories that seem significant.  The list will be posted here when I get to it (holding your breath is not recommended).

On a slightly more informative topic at the moment; this morning's e-mail brought a message from ORA employee Mark Kahan, who mentioned he was having trouble sleeping and found his way to a website on the history of astrophysics.  There he found a recently posted discussion of a painting from 1607 by Jan Brueghel that appears to show a Keplerian telescope some 5 years before it is reported in the literature by Kepler.  This is going to make going to the museum so much more interesting.  It didn’t occur to me to look for optics in the paintings.  The link, which is a quick read and shows the painting could be found at http://arxiv.org/abs/0908.2696v1 and I highly recommend reading it.