Domain: nrao.edu
Stories and comments across the archive that link to nrao.edu.
Comments · 207
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Sun's "free" Solaris X86 - Banned Benchmarks?!I remember that when Sun first made Solaris x86 available for the Intel platform (for free? Academic sites only?) a colleague told me:
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... Note that the license for the free version of Solaris prevents us from
: publishing these benchmarks without clearance from Sun.
This was in the context of some home-brewed benchmarks we were running on various machines. This may not be as insidious as others, but one can only speculate as to why such a clause was invoked in their EULA.
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Re:That will change in time
Let me also clarify something that I just found out myself.
Geo-Synchronous means that the spacecraft is in a general location in the sky, but that it tends to wander in a pattern similar to a figure-8 (due to the wobble of the earth). You do require a tracking subsystem to maintain communications with that type of satellite.
Geo-Stationary means that the satellite appears to be motionless. I think that those types of satellites are controlled by ground controllers who use thrusters to keep them in an imaginary "box" in orbit.
Just wanted to clarify, and if you'd like to read for yourself, try this. (Look for section 3C).
Or this article, which cuts the legs out from underneath your whole argument.
Cheers! and I'll say again: Jeez, is it just me or did the Slashdot crowd used to be better educated than this. -
Re:HUGE problem - TimeHowever, there is one HUGE problem: TIME.
{Snip}
If someone can figure this out, we should have no problems using the whole globe as one big telescope. Good luckSomeone has, the NRAO, with the Very Long Baseline Array
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Re:Iridium was always doomed...Then, the choice of frequency for transmissions. Slap bang in the middle of a *critically* important astronomical region. I may be wrong, but I think it's a CO band.
As a radio astronomer, I have to comment: its the OH line. The VLA RFI plot page clearly shows Iridium: look under L band...
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No. Jagadis Chandra Bose invented the radio :>In fact it was an Indian who invented radio.
From the IEEE Microwave Symposium 1997: "In 1895 Bose gave his first public demonstration of electromagnetic waves, using them to ring a bell remotely and to explode some gunpowder. In 1896 the Daily Chronicle of England reported: "The inventor (J.C. Bose) has transmitted signals to a distance of nearly a mile and herein lies the first and obvious and exceedingly valuable application of this new theoretical marvel." Popov in Russia was doing similar experiments, but had written in December 1895 that he was still entertaining the hope of remote signalling with radio waves. The first successful wireless signalling experiment by Marconi on Salisbury Plain in England was not until May 1897. The 1895 public demonstration by Bose in Calcutta predates all these experiments."
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Astronomy and open source
It's cool that NASA is supporting Linux. But it is certainly true that the field of astronomy has been very Unix oriented for a long time (that is, for those who have given up their VAX systems already.
:) )
Anotheuinr interesting thing about astronomy is the emphasis on open source software. Two of the most popular astronomical data analysis packages in the USA have been open source from the start.
The IRAF project (supported by the NSF) has been open source since it started in the early-mid 80's. It's primarily used for optical and infrared imaging and spectroscopy for ground-based and space-based observation, but it is also used for X-ray astronomy. Nearly all of the Hubble data is processed in IRAF.
Radio astronomers use the AIPS software, which is also open source and has been since its origin in 1978.
Both have supported Linux since about the time RedHat first appeared on the scene. Neither of these packages are recommended for non-specialists, but they are examples of free software which dominate a discipline. -
It's in the National Radio Quiet Zone
Go to www.gb.nrao.edu and click on "Quiet Zone". I used to work at NRAO (about 50 miles away), although I didn't know the Navy had an Echelon site down the road at the time. They have a van that drives around and tracks down stray emissions like old faulty microwave ovens or ham radio operators. The NRQZ was apparently established in 1958, so this has been around for a while. I don't know if the Echelon site or the radio observatory came first.