...and different Geodetic datums
...and different Geodetic datums
There are other ways of looking at the problem:
"You're standing on the surface of the Earth. You walk one mile south, one mile west, and one mile north. You end up exactly where you started. Where are you?"
Other posters have pointed out that "Where are you?" is ambiguous and could mean a Simon says sort of answer like "I'm in your office, Mr. Musk." And also that it could be taken to mean relative to a Sun-centered coordinate system. This latter requires waiting N years to return to the same part of the Earth's orbit.
Once one notices that no time limit is required you get many more solutions by allowing for the polar motion over some period of time: http://en.wikipedia.org/wiki/P... - that is, the pole isn't in the same place at the end as at the beginning.
Then there's the notion of repeating the exercise at the north and south magnetic poles (and perhaps geomagnetic). But there is also no explicit constraint that south, west and north are all interpreted the same - they need not all be geographic or all magnetic. In that case there are families of solutions near each of the four poles that interpret the initial motion one way and the final mile the other.
And then the magnetic poles wander much more rapidly (several miles per year) than the geographic poles and over much more than the mile allowed (http://en.wikipedia.org/wiki/South_Magnetic_Pole), so you can put constraints on the time period allowed for the exercise while exploring solutions covering motions over a few weeks.
It is not true that "there have been many, many, many more attempts at Mars than missions that actually got there", see:
Mars exploration splits into two eras, the cold war competition between the U.S. and Soviets - which the U.S. won hands-down, Yay Mariner! Yay Viking! - and the past couple of decades with the U.S. and other countries collaborating in various combinations.
During the cold war the U.S. had a track record of 8 successful missions versus 2 launch failures. During the recent couple of decades we've had 9 successes versus 3 diverse spacecraft failures. And many of those successes have been far beyond mission profiles. So the NASA Mars team is about 17 wins against 5 losses. This would be regarded as stunningly successful in any sport.
The Soviets in the early days had many launch failures that can't really be charged to the Mars missions themselves - and were about the reverse of the U.S. cold war ratio for those that did get to Mars. It was still a remarkable achievement for them to place any one of those missions in orbit.
There have also been about a half dozen non-NASA Mars missions during the past two decades. Two Russian missions unfortunately continued the trend of never leaving LEO. And now India is one-for-one. May they keep it up! Europe is one-for-two and Japan is zero-for-one. Talk about small number statistics, but that's 2 wins / 2 losses. Quite respectable. One hopes other nations join the fun.
In the aggregate this is a remarkable tally of successful missions considering Mars is never closer than 50 million kilometers or so. Anybody know the corresponding statistics for missions in LEO?
Just as long as he doesn't get his hands on Galaxy Quest. Some things are sacred!
It would be all like "Give up! Surrender!"
"Political Scientist" is a colossal oxymoron.
Whatever this guy and Thomas Friedmann (and alas! Terry Pratchett) say, the world is not flat. Algebraic equations of degree higher than linear (and even - gasp - other than polynomials entirely) are needed to describe how it works. Algebra is the bare minimum to comprehend how functions work. It is telling that TFA doesn't even mention differential equations - the real basecode of the universe. A grounding in algebra provides the most basic of tools to understand graphical representations of a dynamic multivariate world, even without calculus.
That a political scientist would emphasize "lies, damn lies, and statistics" as the pinnacle of mathematics is unsurprising.
NASA Goddard is near Baltimore. They lost power in the storm and are operating under "Code Red": http://www.nasa.gov/centers/goddard/
Quite likely other misbehavior blamed on the leap second is actually the result of the storm (or like Pirate Bay, some unrelated crash).
It depends on the figure of merit and on the measure of central tendency being applied to it. "Average" can mean different things. If the distribution is skewed, the arithmetic mean will always lie to one side or the other of the median.
Stuart Smalley seems the poster child for Dunning-Kruger and related effects.
Astronomical data are background limited. The noise is as interesting as the signal, and many sources lie beneath the noise and are only visible through coadding. The gain and read-noise of LSST's detectors will be tuned similarly to other astronomical cameras because these parameters are governed by the experimental design.
Lossless Rice compression should be around R of 2-2.5 (http://arxiv.org/pdf/0903.2140.pdf) with lossy compression of reduced data products falling between R of 3 to 5 depending on the quantization selected (http://arxiv.org/pdf/1007.1179.pdf).
There will be no delta frame advantage since the compression is governed entirely by the noise (i.e., entropy) due to the sparse signal in astronomical data and the noise is a combination of gaussian and poisson (shot noise) sources that varies from exposure to exposure.
In fact, a key goal of the project is precisely to look for differences between each frame and a baseline static sky so the differences must be preserved in great detail.
Did you know that for the price of a 280-Z you can buy two Z-80's? -- P.J. Plauger