SchildConstruct

Hence the use of 'apparent distance'. Yes, the parsec has a definite length. But the distance between stars that you can observe changes. Pulling an example out of thin air: Wolf 356 and Wolf 425 are 10pc apart from Earth. They are 22pc apart from Tau Ceti. That\'s because your location changes, and thus what you see in the sky. The position of stars is always relative to the position you observe them from. This is analogous to how the position of landmarks changes in relation to each other when you drive by them in a car. That\'s also why geographic surveys are done from determined, well recorded, points.

Yes, but no. SI units, as divorced from the decimal number system, are defined by using cosmological constants. Meter: distance travelled by light in vacuum in 1?299,792,458 seconds Second: the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. Ampere: the amount of electric charge passing a point in an electric circuit per unit time with 6.241 × 1018 electrons, or one coulomb per second constituting one ampere. And so on. The only unit of measurement that is not defined by a cosmological constant is mass. But that is about to change: http://en.wikipedia.org/wiki/Kilogram#Proposed_future_definitions Further, US customary units are defined by SI units, anyway. Quoth the NIST:

No. No, it cannot: http://physics.nist.gov/Pubs/SP811/appenB9.html#TIME And is valid only from your current vantage point. If you change position from Earth to, say, Tau Ceti, the position of the stars changes, and thus their apparent distance to each other.

Why? Keep misplacing the No. 12 wrench?

It still assumes that an individual\'s math skills are relevant. They aren\'t. If you cannot do simple maths (for reference: calculus is 'simple'), it doesn\'t matter what system you cannot do maths in. Fun little anecdote about myself: I use Celsius for daily temperatures (SI unit is Kelvin, no degrees), and meters for distances. When I stayed in the US for a couple of weeks, it took me a couple of weeks before I had internalized Farenheit (which can go to die. Seriously. Look at how it\'s defined, FFS...) and miles and feet, without having to bother with conversions. And I\'m no math whiz. I\'ve since adopted US customary units for cooking (a cup and a spoon are much easier to deal with, than grams and mililiters, and it is all about proportions, not exact amounts, anyway). Yes, but it was kinda implicit that you saw 'km' as a distinct unit (technically: dimension; don\'t ask) from 'm' and 'mm', which it isn\'t. So, you gave me a good opportunity to clear up those misconceptions in general. The parallax second is useful (pretty much only) when you observe stars from Earth, to measure distance between the observed stars. By its very definition, the number of pc between two stars changes if your point of observation changes (fortunately, the change can be ignored when moving a telescope from the ground into orbit). Actually: no calendar, but units of time: 60s per minute, 60 minutes per hour, 24 hours per day, 365 days per year. The definition of 'lightyear' is 'the time light travels in 365 days'. Doesn\'t matter if you use a Mayan, Julian, or Gregorian calendar to track years and festivals and such.

Submitted a bug on Google Code about that...

That\'s why SI units and prefixes are used with the decimal system: Distance is always meters (except when it isn\'t: When talking about humongously large distances, like the distance between solar systems time becomes more interesting, hence the lightyear, or infinitesimally small values, like the distance between an electron and its proton, where Planck effects matter, so Planck units make more sense; that\'s why proton colliders use the electronvolt, eV, for the amount of energy they work with). And the prefixes aren\'t conversions, they are shorthand. It\'s much easier to say 'ten thousand kilometers' than 'ten million meters'. And you know that 1 000 meters can be written as 1 kilometer. The decimal system then allows you to use scientific notation: 1 * 103m = 1 000m = 1 km. Try that with 12 inches to the foot, 3 feet to the yard, 1760 yards to the mile! Lastly, to make everything internally consistent the SI units introduce common prefixes: When I see '10 kN' I know it\'s 10 000 N. Same with distances, speed, Watt, Joule, and so on. It removes the mental overhead of having to deal with how many feet there are to the yard, and I don\'t have to deal with the error that creeps in when doing conversions (1\' = 0.3048m; So, pray tell, how many significant digits do we use? And when? How much is a Mars probe, anyway?).

I\'m assuming you are playing 0.11. Rocketry 101 (you seem to have this one down pat 8), but I want to establish terminology.) Lowest stage: Boosters + Sustaining Stage. Middle stage: Sustaining Stage. Top stage: Orbital stage. The exact layout varies, but the following, with vanilla parts, works: Orbital Stage: 2 liquid fuel tanks, plus engine. Sustaining Stage: 3x3 liquid fuel tanks + engines (via tri-coupler). Add a strut to make things less wobbly--I go from the middle of the top fuel tank to the middle of the opposing, lower fuel tank. Add SAS to taste on top of the whole contraption. Boosters: 3x1 attached to the sustaining stage via radial coupler. Season to taste. Stage Configuration: The Boosters and Sustaining Stage fire together. The next stage are the decouplers for the boosters to get rid of the dead weight. Pre-flight checklist: - Turn on SAS - 50% Throttle - Fasten Kerbal chains safety harness - IGNITION! In flight: - Gain altitude. Once your boosters have burnt out, detach them, and put the pedal to the metal (100% throttle). - Maintain as much throttle until you reach about 30\'000m height. - Take the foot off, especially if you are on your orbital stage already! - Start angling. Take off SAS, use Precision Controls (Caps lock by default). Take it sloooow. Trade vertical speed for horizontal speed slowly. - If you are on your orbital stage, and you like to overshoot your pitch and yaw and rotation, like me, switch on SAS again. - Once you reach apoapsis (check M key for the rough height above ground, watch altimeter and wait until it hits zero), and put the pedal to the metal again. You have to gain a lot of speed in little time (it pays to have the engine running at a minimal throttle during ascend to apoapsis if you are going high) to get into an orbit. See https://gist.github.com/1075144 for pre-calculated values of speed you should have. - If your orbit is too eccentric (i.e. elliptical) for your taste, fire a prograde burn (meaning: in your direction of flight) for a few seconds to circularise your orbit. If you can\'t become circular at your first go, don\'t worry: just wait until you are at Apoapsis again. De-Orbit: - rotate orbital unit retrograde (against the direction of flight). - At Periapsis (the lowest point of your orbit), fire your engines. How much and how long depends on whether or not you want to break Kerbal neck, have Kerbal roast, or feel gracious: The flatter your entry, the fewer g forces and less heat you\'ll have to deal with (once this is implemented, anyway). You should have enough fuel to slow your unit down enough for: - Gravity will do the work for you, and pull you back onto the ground. - Open parachute when in the middle of the atmosphere (roughly; speed should be around 800 m/s to 1000 m/s). Let the atmosphere do the work of slowing you down. While outdated, this video on getting to orbit is still helpful: Have fun, and be crispy!

That\'s a different base which is basically the point where a number system rolls over into tens, hundreds, &c. Forexample Binary (aka 'Base 2'): 0, 1, 10 (decimal: 2), 11 (decimal: 3), 100 (decimal: 4), 101 (decimal: 5), 110 (decimal: 6), 111 (decimal: 7). So, which one is double as loud as 100 Db: 110 Db, or 200Db? What a logarithmic scale helps with is the inverse square law (for every distance unit, the energy level of somethingorother drops by the square root), since that can be turned into a linear graph with relative ease. But take it from me, you don\'t want to work with logarithmic scales. Been there, done that, ate the frikken tee shirt.

And as practice for when g forces are made available: You can open the parachute just fine when you enter the lowest layer of atmosphere, limiting* the g forces acting on Bill, Bob, and Jeb (poor Jeb, never gets to have any fun!). * Side-effects may include internal organ damage, broken bones, and concussions. If erection lasts longer than 4 hours, contact a medical doctor immediately.

The point being: The forumlas used to calculate orbits, escape velocity, &c. work in the game. Meaning that your assertion that in KSP nothing is even slightly realistic doesn\'t hold. And if it\'s that realistic, you might as well use what NASA, ESA, and Virgin use: Metric. It makes it much easier to apply what you learn by causally watching a documentary about space flight to the game, making playing KSP that much easier and fun. When I play something like Falcon 4.0, or Plane X, I use the units used in aeroplanes, as well (Imp. Gallon (US), and feet (US)). Of course, the game isn\'t a total simulation, and will likely never be, but a modicum of realism helps (when flavoured with a good helping of game play). At the moment, KSP shapes up to be just the right mix of 'simulation' and 'arcade', and m * s-2 is part of that. \'course, if someone wants the option to switch to Imperial units, sure, why not? Edification: BB markup. What do you mean, 'Preview it next time'?

*ahem*

To demonstrate this with an example: The Astronomical Unit is 149,597,870.7 kilometres (92,955,807.3 mi), or 149,597,870,700 meters (163 602 220 848 yrd). Wait, nobody uses yard out side of the NFL, so let us use feet, which converts to 490 806 662 544 ft. Since the amount of zeros availbale to us is limited, we can express 149,597,870,700m as 149,597,870.7 *103m, since there are no additional units of length, only the meter, thus enabling the use of the scientific notation (6.67*10-11m3kg-1s-2 for the Gravitational Constant is accurate enough for most people, and way easier to read than 0.0000000000667m3kg-1s-2), as well as easier maths (multiplication/division of exponents is a simple addition/substraction when it\'s the same base).