6 ms·
It's spinning in the wrong direction!
by nikcub 13y ago
It's spinning in the wrong direction!
- coherentpony 13y agoThat's true :)
- srgseg 13y agoReminds me of the episode of the Daily Show where Neil deGrasse Tyson informs Jon Stewart that the Earth is spinning in the wrong direction in the opening credits of the show http://www.youtube.com/watch?v=oy3PgFhIpyM#t=0m56s http://www.youtube.com/watch?v=oy3PgFhIpyM#t=0m56s
- jonsen 13y agoMaybe it was coded on board the ISS.
- xhroot 13y agohttps://s3.amazonaws.com/xhroot/world.html https://s3.amazonaws.com/xhroot/world.html Happy?
- sukaka 13y agonice work. how did you know? For anyone wondering the difference, 0>cos on line 8 is now 0<cos.
- sillysaurus2 13y agoAlmost any kind of rotation in 2D or 3D graphics involves cos or sin. The spinning was going the wrong way, therefore the way to reverse it was to reverse something involving cos or sin. You can then just bruteforce it by reversing each cos until you get the effect you want. (If reversing cos seems to reverse something "perpendicular" to what you want, then you'd need to reverse the sin instead, not the cos.) This is true in almost any context involving 2D/3D graphics, not just for this particular example. It's much more efficient than trying to sit there and think through the math or figure out what does what. But of course you learn less that way, so it's a tradeoff. And sometimes it's less efficient if there are too many combinations to efficiently bruteforce, or if it takes too long to test each iteration. But we live in the age of rapid-iteration javascript.
- asveikau 13y agoI'd also note that in a point on the unit circle, cosine is the x coordinate and sine is the y coordinate. A good reason to try flipping a cosine first. See this: http://en.wikipedia.org/wiki/File:Unit_circle.svg http://en.wikipedia.org/wiki/File:Unit_circle.svg (I still remember how people would describe trig in high school, it is a wonder more teachers didn't explain the cos = x, sin = y thing. Probably because my teachers did not understand math.)
- stinos 13y agoMy teachers did explain it that way. European school, if that matters.
- sillysaurus2 13y agoEuropean school, if that matters. Heh. Yeah, that matters. In my experience, US highschools are very much "Okay class, today we're going to memorize these formulas."
- phaer 13y agoI don't think its that easy, it depends more on the specific school and most of all on the teacher. For the record: I also had to memorize it and i went to an "european" school, or rather to an austrian one. Europe still has a wide variety of education systems.
- riffraff 13y agoand not all systems are uniform. I went to high school in Italy and changed something like 4math teachers. One of them explained the x/y thing, another didn't.
- Locke1689 13y agoSame with the US. Very variable. We went through the unit circle derivation in the 8th grade and were thus showed why cos is conventionally x and sin conventionally y.
- pedroo 13y agoIt's spinning in the right direction. We're just inside the earth :).
- meemoo 13y agoOr... http://www.theflatearthsociety.org/forum/index.php?topic=50167.0#.UjZufmT9C5M http://www.theflatearthsociety.org/forum/index.php?topic=501...
- jafaku 13y agoMovement is relative.
- eru 13y agoOnly inertial movement. Turning is still absolute. (At least in special relativity.)
- magicalist 13y agoWhile rotation spoils an inertial reference frame, this certainly could be a representation of the view of the earth while from a typical (i.e. easterly) orbit. Short of adding an ASCII accelerometer or the like, there's no test you can do on it to demonstrate otherwise. The GP doesn't deserve downvotes any more than the other glib replies above.
- kfury 13y agoIt's spinning in the right direction if you're a satellite in a mid-altitude equatorial orbit.
- aemkei 13y agoThanks for telling me! It is fixed now.
- Achshar 13y agoDamnit, it's fixed. I was freaking out that I had it wrong all along and then after rotating my fist a couple of time I was still damn certain it's moving correct. Parent should probably edit the comment that it has now been fixed.
- wavesounds 13y agoThis is one of the most beautiful pieces of art I've ever seen! ... and the top comment is typical negative nitpicking! Why HN? Why?! There must be a better way!
- anonymous 13y agoBecause it's spinning in the wrong direction.
- deleted 13y ago[deleted]
- TeMPOraL 13y agoWhy do we keep calling it "typical negative nitpicking"? How about calling it "feedback"? Or maybe even "the most useful type of feedback"? We're encouraged here to post things that add value. But that pretty much implies either criticism or going off-topic ("hey, I've seen something similar here:", etc.). There is no practical value in "positive" comments, no matter how elaborately you can write "I liked it". Yes, it will make everyone feel a little bit better, but it hardly contributes anything of value to anyone. Not every criticism is a valuable feedback, but every valuable feedback is a kind of criticism. And I think the best thing about HN is that it has lots of civil nitpicking (usually followed by interesting discussions), instead of circle jerks and compliments. ETA > Why HN? Why?! There must be a better way! There is: it's to stop taking criticism so personally and instead extract as much value from it as one can, and discard the rest. I find it to be a good attitude for life in general, not just HN.
- GrinningFool 13y agoI agree with much of what you said - there is significant value in negative feedback. But here is where I disagree: >... but it hardly contributes anything of value to anyone... >... every valuable feedback is a kind of criticism... Valuable feedback includes positive as well as negative. Negative is actionable feedback, but positive has just as much value in a different way. Most people are aware that their own perceptions, thoughts, and ideas may be flawed. Negative feedback points out those flaws and should always be accepted. Positive feedback says that in spite of the flaws, there is something fundamentally worthwhile there. And while upvotes can certainly serve as a form of positive feedback, words are even better. I'm not suggesting that we should all post meaningless words of encouragement to everything that comes along. But if you're impressed by something you see, saying so only helps.
- abhididdigi 13y agoI'm not sure what you mean by this,'coz movement is relative.