X-Message-Number: 19492 From: Date: Fri, 12 Jul 2002 16:38:56 EDT Subject: Intensity interferometer 6, reading brains in ten years? --part1_15c.103b4699.2a609860_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Building a first imaging intensity interferometer - i cube- is a big project. The give me $ 100 millions and I build it is not an option. some thinking must be invested in the way such an instrument could be made in an incremental way. I suggest three steps: 1/Observation of star ocultation by asteroids. 2/Observation of lone planets (planetars) in interstellar space. 3/Use of the instrument in i-cube mode. 1/ Everybody know about solar eclipse by the Moon. In the same way, stars are eclipsed by asteroids, the common term is then ocultation. In this phenomenon, the shadow of an asteroid move at the surface of Earth. The position of the shadow track defines the precise orbit of the asteroid, the track width gives the asteroid diameter perpendicular to its trajectory (most are not spherical). The asteroid shadow is not clear cut, there are interference fringes on its border. If high speed photometry is used, the starlight oscillates at start and end of ocultation. These fringes with the known position of the asteroid give a way to mesure the angular diameter of the star. If the true diameter is known ( from physical considerations) then this give a direct mesure of the star distance. This may be checked independently if fringes can be observed in different colors ( at least 3). A fringe observer telescope for ocultation of bright stars would have a diameter near 1 m (40"). A color discriminating system would have a diameter in the 80" domain. Up to ten such mobile instruments would have to be lined up perpendicular to a predicted shadow track. This number is necessary to take into account the error margin in track position and to mesure the track width. At this point, we have a first batch of observing, mobile telescopes with single point high speed photometers. When that system has been built, it can be paid by organized travel for interested amateur astronomers. Potential custommer can be recruited through organisations such Iota, IAPPP, AAVSO,... 2/With more telescopes, dark planetars can be detected. As in the first case, stars are oculted by dark bodies. The difference is that we don't know which stars and when. Millions of stars must then be monitored continuously with high speed photometers. The difference with what is requested for i-cube is small, mostly at the software level. What is interesting, is that there is a pending offert to pay for the electronics part of the system if someone pay for the optical part. Exploiting the step 1 system could pay for a telescope making workshop. There is at least one organisation, TASS, giving hardware in exchange for astronomical software writting. A similar scheme could be used (may be with TASS programmers!) giving travels and observing time in exchange for i-cube software making. I think it would be interesting if someone could pick up that project. Well, I know, everybody out there has its own project, problems, investment plans and so on. I am not in the best position to make this myself, but I can try... I have been interested for some time into astronomical photometry. I had a small telescope for some years, I am converting it into a robotic system, computer operated. Near the end of that year I plan to adapt this automatic working to a larger 30" instrument. The 30" scope is the first try in a batch of 38" scopes, I have the raw glass disks for the first two, beyond a second 30". The 38" mirror blanks must be "cooked" before polishing, I have completed in June a special one square meter oven for that. A single excentric polishing machine for one meter mirrors is two week from completion. Unfortunately, it is 400 mi. from my work place, so I can't complete it as fast as I would like. Next year all will be in place to produce one meter telescopes, a project I am after for nearly 10 years. I have a second polishing instrument, a double excentric for two meters mirrors. It needs some adjusting yet to be run at full capacity. The main problem yet is to buy blank mirrors of that size. Because they are too costly, I move towards making these large disks myself. I have started work on a 2.3 m (7.5') kiln with a rotating mold for spincast honeycomb disks. The first mirror could be ready for polishing two years from now. The main problem yet is to have the time to work on these projects. Either, I must quit my current work or I must relocate my workshop. The definitive choice will be made this Autumn. The calendar could be that: First ocultation observing in 3 years, then 5 years to produce 100 instruments in the 2 m class. In 2010 the first i-cube would be running at full power and all the elements would be at hand to make a phonon system. On the other hand, a small group with some money could target directly the end system and build a phonon brain reader in two or three years. Can anyone do that? Y.B. --part1_15c.103b4699.2a609860_boundary Content-Type: text/html; charset="US-ASCII" [ AUTOMATICALLY SKIPPING HTML ENCODING! ] Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=19492