May 1, 2015 06:59:00
May 1, 2015 06:59:00
Celeste Moore SO CLOSE TO FREE DOWNLOADS GAHH! Hooray for Crash Course! :)
May 5, 2015 04:25:42 · Reply
May 1, 2015 20:19:18
Chase Turner Enjoyed the surprise reference to the mechanical adding system -- thanks for including that!
May 2, 2015 17:00:14 · Reply
May 8, 2015 14:17:29
old_MK Well, I was familiar with the basic fact, as evidenced by what your car's windshield looks like after it's been rained on & it dries, but I surely didn't know all the intimate details about water molecules and water clusters. Very interesting! You guys are awesome!
May 9, 2015 02:04:31 · Reply
Cristina Quiroz Hello. I would like you to start doing videos in Spanish again in your YouTube's "Minuto de la Tierra" channel, it would be great. Please, think about it. Greetings from Mexico!
May 23, 2015 00:45:42 · Reply
MinuteEarth Thanks! We've started up the Spanish language videos again!
June 22, 2015 21:39:55 · Reply
Cristina Quiroz Yes, I noticed that. Thanks!!!
June 25, 2015 18:21:46 · Reply
June 1, 2015 06:59:00
June 1, 2015 06:59:00
June 11, 2015 20:23:33
BurmansHealthShop So is My Company going to be Sponsored in your Next Video?? i'll appreciate it GG!!!!! and Have a Nice Day Too?????????
June 19, 2015 20:33:55 · Reply
MinuteEarth Your name appear in our next video! Coming out on Friday! :)
June 22, 2015 14:23:55 · Reply
June 16, 2015 17:01:04
Brenden Bourne It's actually far worse here in the UK, because over here there are 6 parties that now consistently get significant numbers of votes. In the US FPTP somewhat still works, because for the most part there are still only 2 parties that get the vast, vast majority of votes. The most significant problems with the US election system is gerrymandering (for Congress) and the Electoral College (for President).
June 17, 2015 14:14:12 · Reply
Brenden Bourne Choice means nothing when the system is FPTP and gives the seat to whichever candidate gets the plurality, which is almost never also the majority when you've got more than two or three candidates.
June 17, 2015 14:42:28 · Reply
Robert Was it intentional that this video should be viewable by everyone right now? Your note about "early access" doesn't seem to hold up, since I was able to watch this before I logged in to Patreon. It's also publicly available on your youtube channel. So I'm not really sure what "early access" is supposed to mean, here. Don't get me wrong, though. I'm not *complaining*. I'm just confused.
June 16, 2015 18:14:30 · Reply
Gavin Ayling Yup, just tried the link incognito... Definitely allowed me to view... Weird.
June 16, 2015 18:40:24 · Reply
June 25, 2015 16:25:58
July 1, 2015 06:59:00
July 1, 2015 06:59:00
July 1, 2015 06:59:00
July 16, 2015 17:22:55
Michael Richters You think you can't initiate a turn without counter-steering? Not true, as my kids demonstrate to me daily in our bakfiets. Yes, of course simply leaning your torso to one side will cause the bike to tilt the opposite way, but you are neglecting lateral forces that one can apply against the road through the tires. Most bicycles don't have frictionless tires.
July 16, 2015 17:45:57 · Reply
Henry Reich Lateral forces only come from being off balance, not from simply leaning. In order to actually start falling, you must have counter steered (perhaps unintentionally) at least a tiny bit. It's very hard to notice sometimes.
July 16, 2015 17:49:27 · Reply
Michael Richters Counter-steering is certainly the usual way of doing it, and it can be very subtle, but it is not the only way to create the lean necessary for a turn. This would be obvious if you rode a bicycle with a passenger (who has no access to the steering mechanism). When they shift their weight around, they transmit forces through the tires, resisted by the road, causing a lateral wight shift. This effect is not subtle, and is completely independent of my steering motions. Also, if you think active counter-steering is the only way to create a lean, how do you explain the fact that people steer bikes hands-free?
July 16, 2015 18:01:39 · Reply
Henry Reich Ah, I see what the confusion is - by "counter steering" I just mean that the handlebars will turn, not that they have to be actively turned by a rider. For a passenger I'm sure they make it harder to steer, and can change the weight distribution considerably, but if the passenger moves to the right, the bike should lean to the left. Which way does it steer then? If you search for "bricycle" you will find videos of a bike that's been modified to make it un-steerable by leaning.
July 16, 2015 18:13:54 · Reply
Henry Reich I guess what I'm trying to say more specifically is that for a balanced bicycle moving in a perfectly straight line to initiate a turn in one direction, the front wheel contact point has to first move slightly (often imperceptibly) in the other direction. This is a mathematically demonstrated fact.
July 16, 2015 18:19:08 · Reply
Michael Richters Oh, yes, I'm familiar with the "bricycle". You're still failing to understand one thing, though. When the passenger moves laterally, he does push on the bike. And the *bike* leans the opposite way, but that's not all that matters. What really matters is not the angle between the ground and the vertical axis of the frame; what matters is the lateral position of the center of mass of the bicycle/rider system and the point of contact at the ground. If I push against the frame, some of that force leans the bike, but some is resisted by the road, because the wheels don't slip. That moves the center of mass laterally without any steering.
July 16, 2015 18:58:36 · Reply
Michael Richters Something you could try that might convince you (or perhaps you'll see a flaw that I haven't) — stand on one foot, and jump to one side. Then do the same and jump to the other side. You didn't have to first move your foot out from under you, did you? The same should be true of a bicycle. The fact that the rider is free to apply forces from many different points in many directions greatly complicates the question, doesn't it?
July 16, 2015 19:04:20 · Reply
Henry Reich A foot is totally different - it has multiple contact points with the ground, allowing you to apply torques at the ground which help you start leaning in various directions. Where is the torque coming from on a bike to move the center of mass away from the contact point? The rider certainly can't create that torque from inside the system just by changing their mass distribution inside the system. An outside torque/force not at the pivot point is necessary. Gravity is this force (hence the unrideability of the bricycle).
July 16, 2015 19:13:30 · Reply
Michael Richters It can be done on ice skates, too, which are even narrower than bicycle tires. But since that doesn't convince you… Let the rider lean one way, the bike the other way, the let the rider exert a force along the rider's axis, which is now not in line with the point of contact. You must see that this force would be resisted by the ground, and allow the center of mass of the system to shift laterally. This is almost identical to a man in a canoe, who moves from the front end to the back end. The canoe moves under him so that their colnective center of mass doesn't move — but only if there is zero resistance from the water. If we replace the water with a more viscous fluid, that center of mass moves more, until that fluid becomes effectively solid, and the canoe doesn't move at all. The bicycle also doesn't have complete freedom of motion. Lateral forces, even internal ones, cause the bike to lean, but they also push the bike's tires against the road, and that resultant force from the road causes the system's center of mass to move.
July 16, 2015 19:36:21 · Reply
Sergio I Montserrat S And this effect is more noticeable in a bike, where wheel mass and rotation are higher, thus the forces involved in keeping the vehicle upright are higher, and thus riders have to consciously apply counterrotation when they are learning to drive. We don't notice in bicicles because forces are smaller.
July 17, 2015 02:04:25 · Reply
Sergio I Montserrat S It doesn't compare, since the foot and ice skates don't have a torque that works as a gyroscope that actively resists a change in inertia. All other examples you gave also fail to include a gyroscopic stabilizing influence.
July 17, 2015 02:08:24 · Reply
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