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Comment Re:GPS on Mars (Score 1) 104

I'd love to see something like that functional. It could really change what we're doing there. quadcopter or quadcopter/fixed wing hybrids, could do really well exploring the surface of Mars. It's not like there's a rush to get anywhere. They could lay out with solar panels extended for weeks to charge, and then fly for miles. It wouldn't be practical for moving lots of equipment, but it could grab samples and bring them back to the rover/base.

They'd need to take into consideration those pesky sandstorms though. It's not a great place for an aircraft, unless they can automatically secure it. Like have a screw anchor it to the ground (like a tent screw or dog tiedown), and a cover to extend over it and secure itself. Then there's the matter of digging itself out after the storm without killing the batteries.

Comment Re:GPS on Mars (Score 2) 104

That would be a cool trick. I think it will be a long long time before we see that.

GPS, and GLONASS have 24 satellites for global coverage. Galileo has 27. Beidou has 10 right now, but has limited coverage. It will have 35 when it's fully operational.

Most (all?) require ground stations to keep them updated, so it isn't just a matter of throwing some satellites up and having GPS on another planet. As I recall, GPS satellite service will degrade to unusable somewhere between 90 to 180 days. [insert obligatory apocalypse reference]

Theoretically with GPS, you can lock with 3, but that assumes a highly clock on the receiver. Our phones and GPS receivers aren't that accurate, so we require 4 satellites.

But I believe this was dumbed down for the casual reader, so they said "GPS". Using the known location of the orbital vehicle, gravitational center of mars, magnetic poles, and stars optically with a sextant, and using inertial sensors, they could put it down on a precise target.

They might use GPS for test flights here, since we have the luxury on this rock. They aren't accounting for other things with their tests right now. Like the Mars average ground level air pressure is 0.087psi. The summit of Mount Everest is 4.89psi. The highest surface air pressure they'll get on Marswould be Hellas Planitia at 0.168psi.

They're going to need some *huge* propellers on their quadcopter. Flying on Mars is like flying at just over 100,000 feet on Earth. The record for any propeller aircraft is the Boeing Condor UAV with no payload, at 67,028 feet.

The record altitude for a helicopter in Earth's atmosphere is 40,820 feet, and it also got the record for the longest autorotation when the helicopter stopped flying. :)

But other than navigation, and lack of atmospheric pressure, it could work fine. :)

Comment Re:And in other news (Score 1) 139

To tack on... ...I explain this to my wife constantly. The reason most accidents happen close to your home is exactly as you said -- most driving occurs close to your home. I use it as a reason to have her buckle up even for short trips, but it's also a lesson in our house about manipulating statistics.

Coming up next, the percentage of American's that live "near" water.

Comment continuing... (Score 1) 725

(Stupid touchpad...)

  - If this deviation is the result of burning fossil fuels, they are expected to run out in about 800 years - after which the temperature might crash toward the "Ice age already in progress" as the excess carbon is removed from the atomsphere by various processes, or simply be overwhelmed by the orbital mechanical function if it remains.

Does this scenario count as supporting or opposing anthropogenic global warming?

Comment And that, in turn, is political. (Score 1) 725

The percentages come from looking at all studies, papers, research, etc. and determining the number one one side or the /i?

When the administrators of research funding withhold future grants from scientists who publish papers questioning some aspect of the current global warming scenario, while giving additional funding to scientists who publish papers supporting it (or claiming some global-warming tie-in to whatever phenomenon they're examining), the count becomes skewed. This is political action, not science.

This happened in the '70s with research into medical effects of the popular "recreational" drugs - before such research was effectively banned. Among the resuts were a plethora of papers where the conclusions obviously didn't match the data presented and a two-decade delay in the discovery of medical effects and development of treatments. Only NOW are we finding evidence that PTSD might be aborted by adequate opate dosages in the weeks immediately following the injury, or that compounds in marijuana may be a specific treatment for it - as they are for some forms of epilepsy and may be for some cancers, late stage parkinsons, and so on.

The same happens when the editors of a journal and their selection of reviewers systematically approve and publish only research supporting the current paradigms, to the point that scientists with contrary resuts must find, or create, other journals or distribution channels (which can then be smeared as non-authoritaive, creations of the fossil fuel industry, right-wing politicans, or conspiracy nuts - and their articles LEFT OUT OF THE COUNT). Again, this is politics, not science.

Then there's the question of the methodology of the count itself. What is counted as "support for" versus "opposition to"? What does it count as a scientific paper? Were well-established research methods used? Was it reviewed? By whom? Was it done by scientists with no established position on the issue, by scientists supporting one side, by pollsters, by an advocacy group, by politicians? (Hell, was it done at all? Truth is the first casualty of politics, and fake polls are one of the commonest murder weapons.)

For an instance: How would you interpret the study behind the Scientific American article that seems to indicate:
  - Planetary temperatures have tightly tracked a function of three orbital-mechanics effects on the earth's orbit and axial orientation - up to the time of human domestication of fire.
  - That occurred as the function was just starting to inflect downward into the next ice age.
  - The deviation amounted to holding the temperature stable as the function slowly curved downward. (Perhaps a feedback effect - more fires needed for comfort in colder winters?)
  - This essentially flat temperature held up to the industrial revolution, when the temperature began to curve upward, overcoming the gradually steepening decline of the function.
  - If this deviation is the result of burning fossil fuels, they are expected to run out in about 800 years - after which the temperature might crash toward the "Ice age already in progress" as the excess carbon is removed from the atomsphere by various processes, or simply be overwhelmed by the orbita

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