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The Physics of Yoga
03/31/11 | 58m 46s | Rating: NR
James Reardon, Associate Faculty in the Dept. of Physics at UW Madison, puzzles over the yoga phrases: balance, integrity of the pose, work within the pose and the term he finds especially mysterious, press your feet into the floor. He explains their meaning in relationship to the physical concepts of mass, force, and gravity.
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The Physics of Yoga
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James Reardon
All right,
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31:46,20 good evening, everybody. Thanks a lot for coming here
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31:48,67 to Chamberlain Hall at the University of Wisconsin campus,
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31:51,84 Madison, Wisconsin. We are here tonight for a
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31:54,91 presentation on the Physics of Yoga.
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31:58,41 So, my name is Jim Reardon and in addition to being a physicist
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32:03,05 here at the UW, I am a student of yoga.
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32:07,32 I studied with Roger Eischens at Mound Street Yoga here in town.
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32:10,66 And he studied in India, and I learned quite a lot
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32:14,80 from studying with him. I'm not claiming to be a yoga
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32:19,47 teacher tonight, but I would like to try to unpack some
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32:24,51 mysteries of yoga that might not really be part of yoga.
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32:27,38 But merely problem with communication.
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32:30,75 I know that when I studied yoga, there were some words that yoga
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32:34,28 teachers tended to use that I didn't really know what they
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32:37,19 meant. And there are several of those
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32:39,69 that I would like to write down here.
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32:43,76 They would say things like balance.
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32:52,40 They would insist that my yoga pose have integrity.
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33:09,52 They would talk about in order to achieve integrity in the
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33:15,59 pose, they would ask that I do work within the pose.
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33:29,74 And then finally, the most mysterious of all, they would
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33:34,34 ask me to get into a position which I was told was called
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33:40,28 side warrior, which would be something like this.
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33:46,39 Then I was told all right, now press your feet into the floor.
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33:49,26 I didn't know what they meant. I still am not quite sure
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33:51,93 that I know what they mean. But, what I have brought here
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33:56,00 today, the things I was standing on are called force plates and
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34:00,24 we will be able to measure the forces that the human body
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34:03,64 has exerted upon it by the ground, during the course
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34:05,61 of this lecture. We'll be able to measure, to
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34:10,41 quantify the forces involved in yoga poses.
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34:14,12 So hopefully we'll be able to give some meaning,
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34:17,42 some physics meaning to balance, integrity of the pose,
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34:23,36 work within the pose and the especially mysterious
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34:26,36 press your feet into the floor.
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34:47,32 Now that's just my personal list.
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34:49,48 Now, if you have things that you've been told during yoga
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34:52,79 class that you haven't really had explained properly, maybe
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34:56,39 you can bring them up tonight and we can try to figure out
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35:00,40 what the yoga teacher must have meant by mysterious phrases
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35:04,33 that are used. All right.
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35:08,37 So here we are in Chamberlain Hall, we have a bunch of props.
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35:11,51 The first word that I'm going need to define here,
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35:15,34 the first physics word is force. It turns out that it's actually
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35:18,28 very hard to define that word force.
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35:21,92 So I'm lucky that everybody, I hope, already knows
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35:25,75 what a force feels like. If somebody comes up and exerts
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35:30,16 a force on you, you know that someone
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35:32,89 is exerting a force on you. Can I have a volunteer come down
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35:37,43 from the audience and we'll see? All right.
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35:41,17 Thanks a lot for coming down. So my name is Jim.
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35:42,70 What's your name? >> Chloe.
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35:45,41 >> Face the camera, Chloe, all right.
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35:48,38 So, we are going to do a test to see if Chloe knows when someone
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35:50,65 exerts a force on her. Are you ready?
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35:53,28 >> Uh-huh. >> Close your eyes and then if
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35:56,38 you feel someone exerting a force on you, if you feel a new
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36:00,26 force being exerted on you, raise your left hand, all right?
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36:03,26 We are going to start. At any time after now, a force
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36:06,09 could be exerted, but don't do anything until you feel
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36:13,13 a force and when you do, raise your left hand.
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36:16,67 All right. So a force is just a push.
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36:19,14 You can open your eyes. Everybody knows that, right?
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36:22,24 So a force is just like a push. Let's do that one more time,
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36:25,11 just to make sure, all right? Close your eyes, ok?
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36:28,98 All right. So here we go.
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36:32,89 Ready? All right.
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36:36,36 So, did you feel a force? Yeah, when I say push,
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36:38,63 I could mean pull. Push and pull are both types of
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36:40,73 forces. It doesn't matter the direction
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36:43,00 but you know automatically when someone exerts a force on you.
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36:44,53 Great. Thanks a lot, Chloe.
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36:49,24 Go back and sit down again. Physics of yoga.
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36:52,44 Yoga is all about forces but yoga teachers tend to use that
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36:56,95 word in a slightly unusual way. I'll draw your attention to this
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37:00,68 bowling ball here. So, what are the forces that are
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37:05,72 currently acting upon this bowling ball?
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37:11,26 Well, if you can see the bowling ball is hanging from this wire.
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37:14,00 We know, we who have gone bowling, bowling balls have some
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37:16,67 weight. So I'm going to represent the
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37:23,74 force of gravity by this arrow. Now the first thing that I want
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37:26,41 you to take away from this lecture is that whether or not
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37:29,44 you learn anything here tonight you are already experts in
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37:32,61 physics because physics is the study of motion, and everyone
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37:39,15 here already knows how to move. After all, you got here tonight.
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37:41,26 So, you are already an expert in motion.
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37:43,22 You already know how to manipulate forces, to get where
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37:47,00 you want to go. What I hope to teach you tonight
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37:50,47 is the language of arrows. Are there any other forces
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37:56,71 acting on this bowling ball? There's the force of gravity
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38:00,44 pointed downwards. Is there any other force acting
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38:04,25 on the bowling ball? Yeah.
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38:07,95 >> Tension. >> So, which direction does the
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38:10,65 tension force act? >> Upward.
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38:12,95 >> Upwards, that's the tension in the wire up here.
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38:14,92 That's exactly right. I'm going to represent the
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38:23,37 upward force of the wire with this arrow going up like this.
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38:26,47 And so the rule of physics is that if an object is not moving,
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38:29,94 then those arrows have to add up to nothing.
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38:34,44 And when I say add up arrows, I mean head to tail, so that
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38:38,41 means, let me take my arrows off, to add up these two arrows
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38:42,88 I would put them head to tail would be like this.
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38:47,49 So these two forces add up to zero.
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38:55,73 And that has to be the case for any object which is not moving.
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38:58,13 Now we could go further with this language of arrows.
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39:01,87 If you study yoga deeply enough you'll eventually want to learn
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39:05,87 a language called Sanskrit in which the most important
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39:11,05 yoga texts are written. If you want to really dive into
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39:15,42 physics you'll want to learn the language of math, in which
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39:19,05 the most important physics texts are written.
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39:21,92 Sanskrit is a language of great antiquity, being at least 5,000
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39:25,96 years old. Math is a language of equal,
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39:29,76 and perhaps greater antiquity. I don't know if anyone
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39:33,44 has ever told you that math is a language, but it is.
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39:36,60 If you take the trouble to learn it just like you take the
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39:39,61 trouble to learn Sanskrit, you may find that it's
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39:43,78 a lot easier to understand, in this case, physics.
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39:46,78 So, there is our bowling ball.
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39:53,59 Now let's go over here to our yoga master.
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40:02,00 Here is a cut out of a person in --, also known as
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40:10,04 Side Warrior Pose. No, this is, I'm sorry,
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40:12,84 this is Extended Triangle Pose. Extended Triangle Pose,
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40:16,54 my mistake. So, you know how to do this.
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40:18,78 Has anyone ever done this particular pose before in yoga
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40:24,19 class? So, it's not a very hard pose.
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40:27,19 It does share with all the yoga poses the fact that you should
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40:30,03 get into it and stay there for a little while.
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40:33,36 And if you stay there for a little while, that means that
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40:38,40 the forces upon you have to add up to nothing.
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40:40,77 So what are the forces that act upon you when you are on this
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40:45,37 pose? Well, there's the force of
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40:50,75 gravity, just like the bowling ball that points downward.
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40:58,05 And then there's a force on one leg that points upwards,
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41:01,06 put this one over here.
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41:06,96 And then you know you are bearing some weight on the other
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41:11,10 leg, too, so that has to have an arrow representing an upwards
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41:16,50 force on that. And then I need one more arrow
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41:21,11 because in this pose you are resting your hand lightly
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41:26,82 on the floor. So I need a fourth arrow to
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41:31,85 represent the force upwards that the floor is exerting
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41:36,36 on your hand. And so if you want to stay in
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41:41,46 this pose, those arrows all have to add up to zero.
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41:48,80 Now, do you have any control over this arrow?
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41:51,41 The mass arrow. Is there anything you can do
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41:56,18 about the length of that arrow? The length of this arrow is the
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42:00,22 force of gravity upon you. That's equal to your weight.
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42:03,55 So there's nothing you can do about that.
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42:05,85 But these arrows, maybe there is something.
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42:08,06 So what I would like to do, I would like to introduce you
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42:11,49 to our force plates here. I need a volunteer to come down
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42:16,70 and stand on these force plates. These force plates measure
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42:21,20 force, so they'll measure the arrows that are pushing upwards
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42:24,67 on your feet. So who can I get to come
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42:28,68 down to volunteer to stand on the force plates?
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42:30,81 All right. Yeah.
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42:33,11 You could come down from in back, I will set up the force
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42:37,09 plates so you can see their readout.
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42:47,93 All right, great. What's your name?
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42:49,86 >> Phil. >> All right.
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42:52,40 Go ahead and face the audience Phil.
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42:54,30 Are you a student here at the university?
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42:56,40 >> Graduate student, yes. >> Have you ever studied yoga
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42:58,24 before? >> No.
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43:00,98 >> Great, here is your first lesson then.
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43:04,01 The first thing I want you to do is stand on this plate right
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43:07,12 here. This is plate number one.
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43:11,05 Stand on it, you might want to face the screen there.
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43:13,69 So, what I'm going to do, I'm going to start the force plate.
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43:16,22 Hop off it for a second so people can see.
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43:18,93 All right. Now go ahead and stand on the
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43:21,36 force plate. And if you watch the screen, you
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43:23,63 see there is this thing, and if you step off the force plate
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43:27,94 again then that line changes. So let's take a bigger look at
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43:31,64 that line. The first thing I'll do is get
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43:37,25 rid of the old data. And the second thing I'll do
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43:44,65 is blow up this scale here. So can you see that you stood
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43:48,49 on that scale at about three seconds, a little bit after,
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43:50,99 let me blow this up. A little bit after three
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43:53,06 seconds. You stood on the scale and
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43:55,23 it had been reading zero. Now, have you ever measured
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43:57,90 force in Newton's before? >> Yes.
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44:00,04 >> Where did you learn to do that?
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44:03,00 >> In physics class. >> I wonder if anybody else
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44:06,47 knows how to measure force in Newton's.
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44:09,71 I don't want to make this more confusing than it has to be.
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44:13,62 What I think I'll try, let me see if I can go here,
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44:23,89 and let's see if we can change the axis values to pounds.
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44:30,03 I know how to do that. I'll go here
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44:34,74 and I'll go over there and then I'll go over here.
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44:39,64 I'll do that. I'll go over here.
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44:42,31 Because I think we might want to measure things, not in the
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44:45,11 language of science, which is Newton's, but in the language of
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44:49,72 everyday people which is pounds. So, you don't mind if I show
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44:51,99 everybody your weight, do you? >> Go for it.
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44:55,19 >> What we see is there was a force of about zero pounds and
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44:58,06 then you stood on it and it was maybe a little bit more than 150
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45:01,60 pounds and then you stepped off and it went back to zero,
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45:04,13 more or less again. So this thing is basically like
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45:10,21 a fancy bathroom scale. But, we've got two of them.
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45:13,01 So let me call up the other one here.
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45:16,21 And now what I want you to do in a moment is go ahead and when I
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45:18,65 give you the signal stand on the first one and step backwards and
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45:23,65 stand on the other one. So what I want to do is call up
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45:28,29 a force here. Ok.
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45:30,93 So, Phil, go ahead, when you are ready.
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45:35,03 Stand on there. Let me get the start line going.
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45:39,70 So we see from the graph here that's basically the same as
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45:42,70 before. Now go ahead, step backwards
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45:47,41 onto that other one. And we'll see what happens.
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45:49,88 The other one is scale number two.
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45:53,15 I'll stop now. And we'll get another graph
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45:57,72 going here. Normal force two, run three.
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46:05,76 All right. So here we have two graphs,
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46:10,17 I'm sorry it's a lot of clicking in different windows right now.
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46:20,44 And the scale one, which is this one, normal force one--
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46:30,45 And the red one is the data that we want to look at right
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46:33,46 now that shows that you are--
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46:39,79 That got to be parallel force two.
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46:42,23 We want that to be one, so we will try to tell it
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46:46,37 to be one again, so we want it to do that.
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46:51,64 All right. The front scale measured this,
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46:53,94 it measured your body weight until you took the big step
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46:57,05 backwards, and the other one which you are now standing on
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47:00,38 measured your body weight. Let's see what happens
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47:05,75 if you stand on both at once. Okay, go ahead and step off,
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47:07,92 and I'll start taking data now. Go ahead and stand
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47:11,19 on the back one. Now go ahead and take a step
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47:13,90 forward, and stand on both of them at the same time,
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47:17,17 and balance there. So now we have some serious
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47:21,24 wiggles going on. Push forward so you get
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47:26,27 onto the front one, stand there. And then stop again.
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47:30,05 And stop, step off again. All right.
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47:35,05 So let's try to figure out what those things on the screen mean.
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47:39,69 So, it started out, we need a laser pointer.
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47:42,92 I'm going to have to go back and get a laser pointer
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47:45,93 from back here.
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47:55,84 All right. So, you were standing on one
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47:58,64 scale, which one are we looking at?
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48:02,84 Let me get the extraneous data off, we don't need that anymore.
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48:17,76 All right. You were standing on scale two,
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48:22,23 which is the bottom one here. And then you took a step forward
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48:26,13 so that you landed on the front scale, this time in the middle
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48:29,57 your weight was equally on both, more or less.
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48:32,21 And then you took another step forward and ended up on the
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48:35,81 front scale up here. And all your weight was on that.
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48:38,05 All right. Does that make sense?
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48:40,08 >> Yes. >> All right.
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48:42,38 We'll try to do something-- You can do this at home with
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48:44,85 bathroom scales if you wanted. Let's see if your bathroom
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48:48,16 scales can do this! What we also have here is what
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48:52,83 we call the parallel force, so these scales measure not just
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48:57,37 the up and down force but also the side to side force.
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49:02,10 Let's see what that looks like. So if I took the side to side
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49:12,45 force from one, I'll put that here.
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49:20,59 And the side to side force from two and I'll put that down there
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49:26,16 and let's see if we can try to figure that out.
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49:28,90 So, they're in this part, at the beginning, when you are just
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49:32,80 standing on one scale, neither of the side to side forces is
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49:36,50 anything. And at the end when you are only
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49:40,78 standing on scale number one, the side to side forces are also
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49:45,48 zero. But in the middle they're not.
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49:49,95 So in the middle the force that you are exerting on, well,
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49:52,62 what leg is this, this is scale number one, this is your front
49
52,62 -->
019
49:56,19 leg, is in the opposite direction than the force on your
49
56,19 -->
019
49:59,39 rear leg. In other words, this line here
49
59,39 -->
019
50:05,70 is above zero, and this line here is below zero.
50
05,70 -->
019
50:08,74 And that turns out to be a very interesting thing for yoga.
50
08,74 -->
019
50:11,11 All right. So, do you want to try some
50
11,11 -->
019
50:13,44 yoga? >> Sure.
50
13,44 -->
019
50:16,21 >> Okay, so let's see what happens.
50
16,21 -->
019
50:22,42 Now I'm going to ask you to stand on both plates again.
50
22,42 -->
019
50:25,15 All right. We have a live recording going
50
25,15 -->
019
50:29,99 on of everything, let me remove some data so it's more clear.
50
46,68 -->
019
50:49,18 All right. Looks like data studio has
50
49,18 -->
019
50:53,45 beaten me and stopped itself so we have to start over again.
50
53,45 -->
019
50:55,28 All right. So you are now standing
50
55,28 -->
019
50:58,79 on a plate more or less symmetrically.
50
58,79 -->
019
51:01,32 Face the audience perfectly symmetrically.
51
01,32 -->
019
51:04,09 You're not bending to the left, not bending to the right
51
04,09 -->
019
51:06,46 but you're standing straight up. The question is, which direction
51
06,46 -->
019
51:10,40 should we put the arrows that are coming upwards from the
51
10,40 -->
019
51:15,34 ground? So do you mind if we pin
51
15,34 -->
019
51:17,61 some arrows to you? You wouldn't mind.
51
17,61 -->
019
51:20,31 >> Go ahead. >> I do happen to have some
51
20,31 -->
019
51:27,88 arrows over here. Just take them off old BKS.
51
29,85 -->
019
51:33,12 All right. So, here is one arrow that
51
33,12 -->
019
51:35,66 we are going to use to represent your weight.
51
35,66 -->
019
51:37,86 You mind if we see if this velcro sticks to your sweater?
51
37,86 -->
019
51:41,53 >> Sure. >> It doesn't.
51
41,53 -->
019
51:45,57 You'll have to hold that somewhere.
51
45,57 -->
019
51:48,14 A little bit lower down. We'll get into where the center
51
48,14 -->
019
51:51,64 of mass is momentarily, so that's the force of gravity.
51
51,64 -->
019
51:56,08 It has to be balanced by something, it's balanced by the
51
56,08 -->
019
52:00,88 force that the ground is pushing up on you with, so there
52
00,88 -->
019
52:06,29 have to be two arrows down here somewhere, so I'll start with
52
06,29 -->
019
52:12,29 this foot. So we know there's got to be
52
12,29 -->
019
52:18,13 an upward force to balance the downward force of gravity,
52
18,13 -->
019
52:22,14 and the force plate tells me there has to be a sideways
52
22,14 -->
019
52:26,11 force, which way does this arrow go?
52
26,11 -->
019
52:32,31 That's the sideways force that the ground is exerting on Phil.
52
32,31 -->
019
52:37,19 So how many people say the arrow should go this way?
52
37,19 -->
019
52:40,92 How many say the arrow should go that way?
52
40,92 -->
019
52:43,43 All right. Well, it looks like we have some
52
43,43 -->
019
52:45,76 good physicists in the audience, that's right.
52
45,76 -->
019
52:49,13 The arrow does, in fact, point inwards like this.
52
49,13 -->
019
52:52,13 Now, what would happen if it didn't?
52
52,13 -->
019
52:57,21 What would be an example of a surface that you can't have
52
57,21 -->
019
53:00,14 an arrow do anything other than go up?
53
00,14 -->
019
53:03,41 In other words, there's no friction because what
53
03,41 -->
019
53:05,85 we are talking about after all is the force of friction.
53
05,85 -->
019
53:08,85 Could you stand like this on ice?
53
08,85 -->
019
53:12,55 >> No. >> You couldn't?
53
12,55 -->
019
53:16,39 I think we still have some ice on the lake, you might want to
53
16,39 -->
019
53:20,80 go out and try. And that's the secret that
53
20,80 -->
019
53:23,90 we are going to get to over and over again here.
53
23,90 -->
019
53:26,67 You could stand like this on ice but you would have to do
53
26,67 -->
019
53:29,77 something with your muscles. It wouldn't change the shape
53
29,77 -->
019
53:33,91 that you have right now, but it would feel completely different
53
33,91 -->
019
53:37,98 because you can't rely on the force of friction to keep your
53
37,98 -->
019
53:40,92 leg from sliding out sideways the way it would on ice.
53
40,92 -->
019
53:43,42 However, you could, by tensing your abductors, by tensing some
53
43,42 -->
019
53:46,19 muscles in your legs, you could keep it from happening.
53
46,19 -->
019
53:50,56 Why don't you try? Let's see what happens?
53
50,56 -->
019
53:53,46 I'll go ahead and take this back.
53
53,46 -->
019
53:56,53 Let's see, now what would it feel like
53
56,53 -->
019
53:59,77 if you wanted to stand on ice? What would you have to do?
53
59,77 -->
019
54:02,04 >> Squeeze inward. >> Yeah, you personally would
54
02,04 -->
019
54:04,27 have to squeeze your legs together instead of relying on
54
04,27 -->
019
54:08,44 the ground to push you. Let's see if you can do that.
54
08,44 -->
019
54:11,55 So I'm going to start, we are still going with the data here.
54
11,55 -->
019
54:16,38 Go ahead and we're looking at this one here.
54
16,38 -->
019
54:22,02 We're looking at the one with the parallel forces which is,
54
22,02 -->
019
54:29,46 let me get rid of that, and let me get rid of this.
54
34,14 -->
019
54:36,60 All right. We'll zoom out on there so we
54
36,60 -->
019
54:39,04 have a parallel force it looks like of about 18 pounds in each
54
39,04 -->
019
54:42,04 direction.
54
48,92 -->
019
54:51,32 So we are still going, Phil, when you are ready.
54
51,32 -->
019
54:53,49 Try to squeeze, imagine you're standing on ice,
54
53,49 -->
019
54:56,26 squeeze your legs together, can you make the sideways component
54
56,26 -->
019
55:01,70 of the force go to zero? Now, if I allowed you to
55
01,70 -->
019
55:04,53 turn around and look, it would be easy.
55
04,53 -->
019
55:07,17 And in yoga, a lot of this is imagination.
55
07,17 -->
019
55:10,74 So can you just imagine that you are standing on ice?
55
10,74 -->
019
55:14,11 Can you imagine you are not squeezing your legs as tightly
55
14,11 -->
019
55:17,01 together as you could, but you are just imagining
55
17,01 -->
019
55:24,05 that you are standing on ice. So, now I think you'll be able
55
24,05 -->
019
55:28,69 to see here that he's doing a pretty good job, he's still got
55
28,69 -->
019
55:32,26 a little bit of force, but it's a lot smaller than it was.
55
32,26 -->
019
55:37,03 That's brilliant. So if you can see, I don't know
55
37,03 -->
019
55:39,57 if you can see, but that force is very close within a pound or
55
39,57 -->
019
55:42,64 two of zero. All right.
55
42,64 -->
019
55:47,41 You've slacked off a little bit. There you go.
55
47,41 -->
019
55:49,51 There you go. That's back really close to
55
49,51 -->
019
55:52,61 zero. So, you could stand on ice
55
52,61 -->
019
55:54,88 in that position. Is it tiring?
55
54,88 -->
019
55:57,15 >> Yeah. >> It is tiring.
55
57,15 -->
019
55:59,52 It works those muscles. You didn't pump any iron, you
55
59,52 -->
019
56:02,59 didn't go for a run or anything, you just stood there.
56
02,59 -->
019
56:04,79 But yet if you do the right things you can really get
56
04,79 -->
019
56:07,06 a good workout. Thank you, Phil, for staying up
56
07,06 -->
019
56:10,57 here for such a long time. Phil, a university student who
56
10,57 -->
019
56:16,60 now knows a little bit about yoga.
56
16,60 -->
019
56:20,38 Let's see what else we can do with these force plates.
56
20,38 -->
019
56:24,35 Let's see what happens if we get someone who is actually
56
24,35 -->
019
56:29,52 practiced in yoga to come up. So, do we have anyone here
56
29,52 -->
019
56:33,32 who has actually studied yoga before?
56
33,32 -->
019
56:36,56 All right. Chloe, you have, haven't you?
56
36,56 -->
019
56:38,86 >> A little bit. >> A little bit.
56
38,86 -->
019
56:43,90 Well, let's see what happens. So this time, are you
56
43,90 -->
019
56:47,10 familiar with that phrase work within the pose?
56
47,10 -->
019
56:49,70 >> Yes. >> So let's try that.
56
49,70 -->
019
56:52,41 So what's your favorite pose that you could do
56
52,41 -->
019
56:58,08 on two force plates? >> Probably what you were doing,
56
58,08 -->
019
57:05,39 like what he was doing. I can't think of it.
57
05,39 -->
019
57:07,89 >> It's one of the maybe front warriors or front lunges so you
57
07,89 -->
019
57:10,96 come down with the knee bent. Let's see what happens when you
57
10,96 -->
019
57:17,00 do that. So, let's see, we have there
57
17,00 -->
019
57:19,60 and you can-- >> This?
57
19,60 -->
019
57:23,74 >> Yep, so let me get-- Step off for a second.
57
23,74 -->
019
57:30,85 Wwhat I'm going to do is take this stuff off the screen.
57
30,85 -->
019
57:34,52 Let's see, I guess the easiest way for you to see what you're
57
34,52 -->
019
57:37,35 doing is stand the way that you are, yeah, so let's
57
37,35 -->
019
57:40,32 get run five off here.
57
43,76 -->
019
57:46,76 And we're looking--
57
49,56 -->
019
57:52,43 There's two questions that we want answer.
57
52,43 -->
019
57:58,54 What happens to the normal force, in other words, when you
57
58,54 -->
019
58:01,91 go into that pose, how is your weight distributed?
58
01,91 -->
019
58:04,28 Do you have more weight on your front leg or do you have more
58
04,28 -->
019
58:08,28 weight on your back leg. And then we'll see what happens
58
08,28 -->
019
58:14,52 if you go from just standing and sort of the right shape to
58
14,52 -->
019
58:19,53 standing in the correct yoga technique that you've been
58
19,53 -->
019
58:21,93 taught. We'll see what kind of
58
21,93 -->
019
58:24,77 difference that makes. All right.
58
24,77 -->
019
58:27,77 So, I'm fiddling around, trying to remove all of this old data
58
27,77 -->
019
58:35,04 from here and we'll put the normal force down there.
58
35,04 -->
019
58:41,98 Oh, look, it did something, interesting.
58
41,98 -->
019
58:46,15 And then we'll put the other normal force down there.
58
54,16 -->
019
58:57,17 All right. So, when you are ready,
58
57,17 -->
019
59:02,60 go ahead and step on the scale. And just hang out there in a
59
02,60 -->
019
59:05,24 comfortable pose for a moment while I get rid of all this
59
05,24 -->
019
59:09,58 stuff so it's easier to see what's going on.
59
14,22 -->
019
59:16,89 All right. So that's you right now.
59
16,89 -->
019
59:19,89 With a parallel force.
59
25,49 -->
019
59:31,80 And this is statistics. How did that happen?
59
31,80 -->
019
59:34,24 Computers. Oh, that's what happened.
59
34,24 -->
019
59:37,54 All right. So get rid of that.
59
37,54 -->
019
59:42,54 I'll get rid of this. All right.
59
42,54 -->
019
59:45,28 And there we are with the normal force, and I didn't want that.
59
45,28 -->
019
59:50,89 I said normal. I told you normal force.
59
50,89 -->
019
59:53,89 Fascinating.
59
59,89 -->
020
00:02,80 I'm sorry that physics, there is a certain amount of messing
00
02,80 -->
020
00:05,30 about with physics and this type, usually computers have
00
05,30 -->
020
00:12,34 something to do with it. I have to start all over again.
00
12,34 -->
020
00:15,81 You can stay on, I think I have managed to arm wrestle this
00
15,81 -->
020
00:18,81 computer into submission.
00
22,28 -->
020
00:33,13 All right. So there is the parallel forces.
00
33,13 -->
020
00:35,83 And the thing doesn't like it when I take that one away.
00
35,83 -->
020
00:38,17 That's just too bad. All right.
00
38,17 -->
020
00:40,44 We'll have to make another graph.
00
40,44 -->
020
00:44,81 So we have the parallel forces going fine.
01
21,71 -->
020
01:25,78 Okay, I think we've got it going there.
01
25,78 -->
020
01:31,22 So what we are seeing here on the graph number four,
01
31,22 -->
020
01:35,72 this one is, which weight do you have, which leg
01
35,72 -->
020
01:39,49 do you have more weight on? So you already know a lot about
01
39,49 -->
020
01:42,33 physics. Yes.
01
42,33 -->
020
01:44,83 So you know if you come down and lean like that, you get into the
01
44,83 -->
020
01:48,47 front warrior pose that you have more weight on the front leg and
01
48,47 -->
020
01:51,64 less weight on the back leg so we can see there is twice as
01
51,64 -->
020
01:56,34 much weight on the front leg, near 100 pounds as the back leg,
01
56,34 -->
020
02:01,75 down closer to 50. Meanwhile you see the parallel
02
01,75 -->
020
02:07,16 force on top, then on the front leg you've got about 20 pounds
02
07,16 -->
020
02:10,16 going backwards, and on the back leg, you have about 20 pounds
02
10,16 -->
020
02:13,09 going forwards. All right.
02
13,09 -->
020
02:16,67 Now, what happens when you work within the pose?
02
16,67 -->
020
02:19,20 >> Stabilize yourself. >> Exactly.
02
19,20 -->
020
02:22,30 That's exactly, uh-huh. Yep.
02
22,30 -->
020
02:24,37 So, I'm going to stop distracting you.
02
24,37 -->
020
02:27,21 Do what you have to do. You might find it interesting
02
27,21 -->
020
02:31,61 to look there. >> Okay.
02
39,05 -->
020
02:41,26 So right now we learn a couple of things.
02
41,26 -->
020
02:44,03 You could not do what you are doing now on ice.
02
44,03 -->
020
02:47,26 >> No, I would do the splits. >> So you would do the splits,
02
47,26 -->
020
02:49,80 exactly. That's very important.
02
49,80 -->
020
02:52,17 I thought for a number of years when my yoga teacher was telling
02
52,17 -->
020
02:54,64 me to force my feet into the ground, to press my feet into
02
54,64 -->
020
02:58,57 the floor that what I ought to do is press them together like
02
58,57 -->
020
03:01,61 I would have to do in order to stand on ice and I now know,
03
01,61 -->
020
03:04,18 because I brought my yoga teacher in here to do it on the
03
04,18 -->
020
03:08,35 force plates, that that's not true.
03
10,79 -->
020
03:13,32 Now, meanwhile, if you do that again, you come back into the
03
13,32 -->
020
03:17,53 neutral pose, and the weight goes--
03
17,53 -->
020
03:20,40 That's the bottom graph. It shows you are almost equal
03
20,40 -->
020
03:23,13 weight on the front and on the back, there is no real front and
03
23,13 -->
020
03:26,94 back at this point. Now if you come down into the
03
26,94 -->
020
03:31,14 warrior pose, yeah, more weight goes into the front leg.
03
31,14 -->
020
03:33,91 What happens if you try to drive your back leg into the
03
33,91 -->
020
03:42,48 floor, to press down on it? So it looks like you can.
03
42,48 -->
020
03:45,49 Now, were you really pressing straight down on your back leg
03
45,49 -->
020
03:48,82 without moving anything else? Let's see you do it again.
03
48,82 -->
020
03:50,99 Or did you have to lean over a little bit backwards?
03
50,99 -->
020
03:53,56 Oh, ok. See what you can do without
03
53,56 -->
020
03:56,36 changing your shape. What work can you do
03
56,36 -->
020
04:01,60 within the pose? And yeah, feel free to watch.
04
06,21 -->
020
04:08,71 >> I'm trying to dig my heel into it.
04
08,71 -->
020
04:11,38 >> Whatever you feel it takes to try to drive, only you cannot
04
11,38 -->
020
04:13,88 actually lean backwards or move backwards or put both arms
04
13,88 -->
020
04:19,62 backwards like this. Let's just make sure that
04
19,62 -->
020
04:22,02 everyone understands what happens if you do those things.
04
22,02 -->
020
04:24,76 If you are standing like that, and bring both arms like that
04
24,76 -->
020
04:29,36 backwards, you can actually-- It's slipping?
04
29,36 -->
020
04:31,63 Oh, no, okay. We better bring it
04
31,63 -->
020
04:34,64 a little bit closer.
04
39,74 -->
020
04:44,25 >> Both arms back? >> Uh-huh.
04
45,81 -->
020
04:48,65 All right. So we have, what is it?
04
48,65 -->
020
04:51,89 It's reversed, actually. So let's make sure we are clear
04
51,89 -->
020
04:54,09 which one is the front one. If you lean all the way forward
04
54,09 -->
020
04:58,03 onto the frong leg, so the orange is the front one.
04
58,03 -->
020
05:01,76 Are you capable of keeping that front leg bent at 90 degrees,
05
01,76 -->
020
05:04,53 say, like you are in warrior pose?
05
04,53 -->
020
05:07,24 Can you get an equal amount of weight onto the back leg
05
07,24 -->
020
05:09,97 by, say, moving your arms back or leaning backwards?
05
09,97 -->
020
05:13,41 It looks like you just about can.
05
13,41 -->
020
05:15,61 >> It's hard. >> It's hard to do that.
05
15,61 -->
020
05:19,45 Yeah. All right.
05
19,45 -->
020
05:21,92 So what did we learn? There is a point in the middle
05
21,92 -->
020
05:24,75 where you were bringing your legs together and able to make
05
24,75 -->
020
05:29,22 the parallel force go to zero, so you were able, you could do
05
29,22 -->
020
05:33,03 that pose on ice if you wanted to, but that's not part of your
05
33,03 -->
020
05:35,80 practice because when you are trying to do the practice
05
35,80 -->
020
05:38,37 properly, then the force was quite different.
05
38,37 -->
020
05:40,80 All right, splendid. Thanks a lot for helping us out
05
40,80 -->
020
05:44,94 with that. >> No problem.
05
47,31 -->
020
05:50,38 >> All right. So, there is two words
05
50,38 -->
020
05:54,55 in physics that we have to use to talk about what one does
05
54,55 -->
020
05:57,52 in yoga. So I'll write those two words
05
57,52 -->
020
06:00,52 here.
06
01,56 -->
020
06:06,26 I'm going to draw a line like this.
06
06,26 -->
020
06:09,26 So this is the yoga part.
06
10,63 -->
020
06:13,40 And here I'm going to try to translate the yoga part into the
06
13,40 -->
020
06:16,40 physics language.
06
23,91 -->
020
06:26,95 The first physics word that I need to use to explain what my
06
26,95 -->
020
06:30,39 yoga teachers are telling me is that one, equilibrium.
06
30,39 -->
020
06:32,62 And we have already covered that.
06
32,62 -->
020
06:36,96 That means that all the arrows--
06
44,63 -->
020
06:47,64 Add up to zero.
06
52,61 -->
020
06:56,41 What happens if all the arrows don't add up to zero?
06
56,41 -->
020
07:00,15 Well, what would be an example of an object that just had
07
00,15 -->
020
07:06,19 one force on it? Yeah, Phil?
07
06,19 -->
020
07:08,69 >> Falling bowling ball. >> A balling bowling ball.
07
08,69 -->
020
07:12,53 That's right. If I were to cut this wire, that
07
12,53 -->
020
07:15,76 would remove the tension force that is pulling up, and all
07
15,76 -->
020
07:18,57 that would be left is the gravitational force,
07
18,57 -->
020
07:23,14 the arrow pointing downwards. And since there's only one
07
23,14 -->
020
07:27,14 arrow, the resultant arrow would be pointing downwards and
07
27,14 -->
020
07:30,91 the resultant motion would be a downwards fall.
07
30,91 -->
020
07:33,42 So, if you don't want to fall down, you have to make sure all
07
33,42 -->
020
07:36,22 your arrows add up to zero and human beings are very good at
07
36,22 -->
020
07:39,32 that, as long as it's not bar time.
07
39,32 -->
020
07:42,99 You rarely see adults falling over and that means they are
07
42,99 -->
020
07:49,73 maintaining equilibrium. But the other word
07
49,73 -->
020
07:57,61 that we have to use if we want to say what is yoga,
07
57,61 -->
020
08:00,61 is stability.
08
03,21 -->
020
08:05,81 That's a very important physics concept which is also a very
08
05,81 -->
020
08:09,48 important yoga concept. Let me quantify stability.
08
09,48 -->
020
08:13,25 I need another volunteer from the audience.
08
13,25 -->
020
08:20,20 All right, Phil. Thanks a lot for coming down.
08
20,20 -->
020
08:22,73 Do you have good balance? >> I think so, yes.
08
22,73 -->
020
08:26,30 >> All right. Let's find out.
08
26,30 -->
020
08:28,77 So, what I want you to do is to stand on, let's say, force plate
08
28,77 -->
020
08:35,54 number one. It doesn't matter, you can go
08
35,54 -->
020
08:45,15 ahead and stand right now. And what I'm going to do
08
45,15 -->
020
08:50,73 is put a graph on of the parallel force--
08
54,83 -->
020
08:59,53 On that, which is actually not started yet.
08
59,53 -->
020
09:04,74 So, go ahead and start taking data right now.
09
04,74 -->
020
09:11,71 Parallel force run number ten, scale number one.
09
11,71 -->
020
09:17,62 All right. So you're standing around,
09
17,62 -->
020
09:21,12 not doing anything, but the parallel force still has
09
21,12 -->
020
09:25,06 some fluctuations in it. You can, I suppose, turn and
09
25,06 -->
020
09:27,70 face me and maybe see the fluctuations over there on the
09
27,70 -->
020
09:32,47 screen. All right.
09
32,47 -->
020
09:34,67 Let me zoom out a little bit, zoom in a little bit I mean
09
34,67 -->
020
09:37,97 so that you can see better. And I want to see what happens
09
37,97 -->
020
09:46,61 to those fluctuations if you now stand on one foot.
09
46,61 -->
020
09:50,35 So, go ahead and keep your balance as best you can.
09
50,35 -->
020
09:53,12 Ok. You notice that it's harder to
09
53,12 -->
020
09:57,29 keep your balance exactly and you have to wobble around,
09
57,29 -->
020
10:00,33 or you do wobble around a little bit more.
10
00,33 -->
020
10:02,10 All right. But you are pretty stable,
10
02,10 -->
020
10:04,67 you are pretty good, you are balancing successfully
10
04,67 -->
020
10:06,90 on one foot. It's been 15 or 20 seconds now,
10
06,90 -->
020
10:09,10 that's very good. Are you ready for another
10
09,10 -->
020
10:11,91 challenge to your balance? You are in front of a bunch of
10
11,91 -->
020
10:14,11 people, it could be tough, all right, because I'm going to ask
10
14,11 -->
020
10:19,05 you to close your eyes and it's now 75 seconds, all right?
10
19,05 -->
020
10:24,15 So close your eyes, that's it, come on, I know you can do it.
10
24,15 -->
020
10:27,42 You're doing great. It's been 10 seconds now.
10
27,42 -->
020
10:31,53 75 to 85 seconds. For the last challenge, the most
10
31,53 -->
020
10:35,40 difficult balance trick of all, all right.
10
35,40 -->
020
10:39,67 I want you to close your eyes and stand up on your tiptoes.
10
39,67 -->
020
10:42,50 Close your eyes. No, you have to do it
10
42,50 -->
020
10:45,01 on one foot, though. >> I have to get started,
10
45,01 -->
020
10:47,24 though. >> All right.
10
47,24 -->
020
10:49,58 It's now 100 seconds. You are doing great.
10
49,58 -->
020
10:53,25 Keep it as long as you can. All right.
10
53,25 -->
020
10:56,32 Excellent. From 100 to 110.
10
56,32 -->
020
11:00,66 Now let's see how you did. So this is the trace of your,
11
00,66 -->
020
11:05,53 of you standing on one foot, two feet, two feet then one foot
11
05,53 -->
020
11:09,13 then one foot eyes closed and then finally one foot
11
09,13 -->
020
11:12,13 eyes closed and on tiptoes.
11
17,74 -->
020
11:22,41 So, this is, from 30 to 40, that is the time from 30 to 40
11
22,41 -->
020
11:27,42 seconds when you were balanced on two feet.
11
27,42 -->
020
11:31,62 So let's see if we can get a standard deviation for that.
11
33,29 -->
020
11:36,22 If you don't know what standard deviation means,
11
36,22 -->
020
11:40,10 then it's just the size of the fluctuations, it's the width of
11
40,10 -->
020
11:44,60 that line, the width of that hash, if you will.
11
44,60 -->
020
11:47,94 So, let's see if we can get a standard deviation out of this.
11
47,94 -->
020
11:49,74 It's one of these things, is it this one?
11
49,74 -->
020
11:52,11 No. Is it this one?
11
52,11 -->
020
11:54,48 I don't want that one. Is it this one?
11
54,48 -->
020
11:57,38 No. It's what?
11
57,38 -->
020
12:01,72 >> Go to the arrow on the side of the sum button.
12
01,72 -->
020
12:03,89 >> Standard deviation is what we want.
12
03,89 -->
020
12:08,06 So the standard deviation of that was.03 pounds.
12
08,06 -->
020
12:10,96 So that's a quantification of your balance.
12
10,96 -->
020
12:16,77.03 pounds. So now for this part here--
12
21,20 -->
020
12:24,27 All right. So, is this automatically
12
24,27 -->
020
12:29,44 tracking it when I move? 4 and 20, all right.
12
29,44 -->
020
12:33,08 Then we'll go over here to the last one.
12
33,08 -->
020
12:37,59 So for this part you are doing something really hard, you are
12
37,59 -->
020
12:41,12 trying to balance on one foot, on tip toe with your eyes
12
41,12 -->
020
12:46,26 closed, so the standard deviation is now a lot larger,
12
46,26 -->
020
12:49,73 3.35. So how does that compare
12
49,73 -->
020
12:53,87 to.03? So that's about 100 times, yeah.
12
53,87 -->
020
12:56,97 So your balance is 100 times better when you are standing on
12
56,97 -->
020
13:00,68 two feet with your eyes open than when you are balancing on
13
00,68 -->
020
13:06,05 tiptoes with your eyes closed. We have some intermediate values
13
06,05 -->
020
13:10,42 from 75 to 85. So that would be about
13
10,42 -->
020
13:14,82 like here. So that was the,
13
14,82 -->
020
13:18,19 just one foot eyes closed. All right.
13
18,19 -->
020
13:22,30 So here for this part we have a standard deviation of 16,
13
22,30 -->
020
13:25,50 so how is that? That's five times worse
13
25,50 -->
020
13:29,44 than the first case, but it's a lot better than the second.
13
29,44 -->
020
13:32,47 That's about 20 times better than the second.
13
32,47 -->
020
13:35,44 All right. And then let's see, before that
13
35,44 -->
020
13:39,58 the one foot eyes open, I think that was here.
13
39,58 -->
020
13:42,42 And so it seems like you must have pretty good balance because
13
42,42 -->
020
13:45,49 there wasn't much difference between--
13
45,49 -->
020
13:48,12 Let's make sure that's true. Let's do this over again.
13
48,12 -->
020
13:50,66 >> Ok. >> One more time.
13
50,66 -->
020
13:53,13 You know what I want to you do, so let's do it more quickly.
13
53,13 -->
020
13:56,13 Don't get on just yet.
13
59,40 -->
020
14:03,84 So, we'll take data, all right? Go ahead and stand on it.
14
03,84 -->
020
14:08,81 >> Two feet? >> Uh-huh, two feet.
14
08,81 -->
020
14:11,31 Let me get the graph up. This is run 11,
14
11,31 -->
020
14:19,22 parallel force one. So there you are.
14
19,22 -->
020
14:23,93 Stand on one leg, now. That's at 20 seconds.
14
23,93 -->
020
14:30,80 We'll hold you there for 10 seconds until we'll say 31.
14
30,80 -->
020
14:34,54 Now when I give the signal, close your eyes.
14
34,54 -->
020
14:40,51 Ready, and now, at 35 seconds you close your eyes.
14
40,51 -->
020
14:42,24 That's fine. But we'll count it
14
42,24 -->
020
14:45,71 as a fluctuation. All right.
14
45,71 -->
020
14:49,18 And we'll see five seconds, go on the tip toe, right now.
14
49,18 -->
020
14:55,89 At 50 seconds. All right.
14
55,89 -->
020
14:58,86 So, let's see if we get the same answer for the statistics
14
58,86 -->
020
15:03,67 out of this. So, at the beginning, two feet,
15
03,67 -->
020
15:07,70 you stand on it that's here, we'll look at two feet from
15
07,70 -->
020
15:12,64 there, standard deviation,.03 again.
15
12,64 -->
020
15:15,24 That's the same as we got the first time.
15
15,24 -->
020
15:19,61 So maybe I should believe that. Then you stood on one leg,
15
19,61 -->
020
15:23,62 that happened at 21 seconds. So, we'll look at that
15
23,62 -->
020
15:27,66 from 21 to about 30. And we got the same answer.
15
27,66 -->
020
15:31,36 Look at that. Its.03 pounds again.
15
31,36 -->
020
15:33,96 So you really do have just as good balance, it looks like,
15
33,96 -->
020
15:36,63 on one leg as two. That's very rare.
15
36,63 -->
020
15:40,27 Do you practice? >> No.
15
40,27 -->
020
15:44,81 >> And then from 35 onwards, then that was the one,
15
44,81 -->
020
15:50,01 that was what? One leg with eyes closed,
15
50,01 -->
020
15:53,62 all right? So we had some fluctuation
15
53,62 -->
020
15:56,95 right there and obviously, big fluctuation, and we got
15
56,95 -->
020
16:01,39.15 the first time,.12 the second time.
16
01,39 -->
020
16:04,49 And then at 50 or so, a little before 50, that's when
16
04,49 -->
020
16:07,20 you try to go on the tiptoes and that's really hard to do, not
16
07,20 -->
020
16:11,07 many people can do that at all, so we have a standard deviation
16
11,07 -->
020
16:15,64 that's about the same. So if I click on everything
16
15,64 -->
020
16:19,04 there, we get a little better that time, but 1.9,
16
19,04 -->
020
16:23,24 that's still a lot harder. Thanks a lot, Phil.
16
23,24 -->
020
16:26,25 You can go sit down again.
16
28,98 -->
020
16:32,85 So what we can measure here in the physics lab that is
16
32,85 -->
020
16:37,49 important for yoga is, let me get an arrow here again.
16
37,49 -->
020
16:44,23 So if you are standing on a force plate, you have
16
44,23 -->
020
16:48,74 gravity going downwards. You have the force that the
16
48,74 -->
020
16:53,94 force plate exerts on you going upwards.
16
53,94 -->
020
16:57,05 But you, being a human being and not being a block of stone or
16
57,05 -->
020
17:01,95 something are not capable of exerting a constant force.
17
01,95 -->
020
17:05,69 So this arrow is constantly jiggling around.
17
05,69 -->
020
17:09,02 And what we were measuring there on the screen was the side to
17
09,02 -->
020
17:15,33 side motion of this arrow. So when anybody stands, no one,
17
15,33 -->
020
17:19,70 no one is capable of having a completely constant force.
17
19,70 -->
020
17:22,84 Everybody wobbles a little bit. And what we can measure and
17
22,84 -->
020
17:29,74 quantify is the amount of that wobble.
17
29,74 -->
020
17:32,65 So, someone who has good stability--
17
32,65 -->
020
17:36,79 Where's my pen? It's over here.
17
39,95 -->
020
17:42,96 So good stability.
17
48,93 -->
020
17:52,27 I'm going to have to remove-- Anyone want a cheap
17
52,27 -->
020
17:55,27 bowling ball? So it's not real good
17
55,27 -->
020
17:57,81 for bowling, because it has this hook in it.
17
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020
18:00,41 Going once, going twice-- All right.
18
00,41 -->
020
18:04,61 I guess we get to keep our bowling ball then.
18
08,25 -->
020
18:13,89 So good stability, let me write this slightly more neatly.
18
37,68 -->
020
18:41,12 So in order to be stable you have to minimize the fluctuation
18
41,12 -->
020
18:44,92 of the ground forces. So that's what the yoga teacher,
18
44,92 -->
020
18:49,06 let's go back to our list here, so I can draw this talk
18
49,06 -->
020
18:52,26 to a close. The balance, when a yoga teacher
18
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020
18:54,36 talks about good balance, I think what they mean is they
18
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020
18:58,93 want you to minimize the fluctuations that are in your
18
58,93 -->
020
19:03,07 ground forces. Now, is it possible
19
03,07 -->
020
19:06,31 that you can do that? And the answer is
19
06,31 -->
020
19:08,64 it turns out to be yes. Now I don't claim to be a yoga
19
08,64 -->
020
19:12,81 teacher, but I think I know how to do that.
19
12,81 -->
020
19:17,49 Now, I'm not sure if we can actually do this live.
19
17,49 -->
020
19:19,92 You might not be able to do this live because I am not a yoga
19
19,92 -->
020
19:23,36 teacher. But let's see what happens.
19
23,36 -->
020
19:26,06 So, can we get someone up who wants to see if they can improve
19
26,06 -->
020
19:31,63 their balance in realtime by doing yoga work within the pose?
19
31,63 -->
020
19:34,00 All right. Chloe, thanks a lot for helping
19
34,00 -->
020
19:38,37 us out so much. All right.
19
38,37 -->
020
19:40,78 Now, go ahead and turn and face the cameras a bit.
19
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020
19:43,45 Is this the sort of thing that your yoga teacher says?
19
43,45 -->
020
19:47,82 >> Yeah. >> What sorts of thing does your
19
47,82 -->
020
19:51,75 yoga teacher say? >> She says just to stabilize
19
51,75 -->
020
19:54,89 yourself, and the breathing is so important.
19
54,89 -->
020
19:58,33 That helps the stability, too. >> Mm-hmm, breathing.
19
58,33 -->
020
20:01,10 >> Constant breath, constant kind of motion within your body.
20
01,10 -->
020
20:03,67 >> So you are emphasizing your breathing.
20
03,67 -->
020
20:05,77 >> Yep. >> All right.
20
05,77 -->
020
20:07,80 Well, do you mind if we see if that makes a difference?
20
07,80 -->
020
20:10,47 >> Sure. >> So I don't know if it will,
20
10,47 -->
020
20:12,84 and I realize it's an artificial environment for doing yoga,
20
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020
20:16,64 and it's not the most relaxing environment in which to do yoga,
20
16,64 -->
020
20:20,78 but let's go ahead and give it a try.
20
20,78 -->
020
20:22,92 I remember we had a little problem with the force plates
20
22,92 -->
020
20:27,02 being too far apart, we'll move them a little bit closer.
20
29,99 -->
020
20:31,93 All right. So do you know what pose
20
31,93 -->
020
20:34,40 you want to do for us tonight to practice, to show off
20
34,40 -->
020
20:39,37 the breathing as a method of stabilizing?
20
39,37 -->
020
20:47,54 >> Yeah, I'll just do the same. >> Whatever your favorite is.
20
47,54 -->
020
20:51,78 >> Actually, I might do warrior 3, the forward one.
20
51,78 -->
020
20:54,88 >> Really, yeah. You're going to do Warrior 3.
20
54,88 -->
020
20:57,62 That's a one-legged pose. >> I'll try it.
20
57,62 -->
020
21:00,52 >> Wow, okay, great. This will be a great test,
21
00,52 -->
020
21:04,06 because it's not that easy to balance on one leg.
21
04,06 -->
020
21:08,83 >> The first time, really. >> I'm not going to put any data
21
08,83 -->
020
21:11,93 on the screen. So how long would be reasonable
21
11,93 -->
020
21:14,50 to ask you to just stand like that?
21
14,50 -->
020
21:16,60 And then how long would be reasonable to ask you to
21
16,60 -->
020
21:21,51 practice the yoga in that pose? Like 30 seconds for each?
21
21,51 -->
020
21:24,11 >> Sure. >> All right.
21
24,11 -->
020
21:28,08 >> Just standing? >> So, I'll ask you to stand
21
28,08 -->
020
21:29,92 for, let's cut it short so you don't get tired.
21
29,92 -->
020
21:39,79 15 seconds starting right, now. 30 seconds.
21
46,97 -->
020
21:49,57 So at this point, are you just standing?
21
49,57 -->
020
21:53,71 Or is that the yoga? >> I'm standing in a pose.
21
53,71 -->
020
21:56,21 >> But you are not doing the careful breathing stuff.
21
56,21 -->
020
21:59,61 Perfect, all right. I'm going to ask you to start
21
59,61 -->
020
22:02,95 the breathing stuff in five seconds.
22
02,95 -->
020
22:05,32 So, when you are ready, start it and just hold it as long as you
22
05,32 -->
020
22:09,82 want, at least 15 seconds. Start it now.
22
30,41 -->
020
22:33,21 Okay, all right. So let's see what happened.
22
33,21 -->
020
22:37,09 Now how did you feel? Let me first ask you how you
22
37,09 -->
020
22:40,92 felt doing first, just standing in that position and then
22
40,92 -->
020
22:44,33 second, doing the actual yoga techniques of relaxation through
22
44,33 -->
020
22:46,59 breathing. How did you feel?
22
46,59 -->
020
22:49,50 >> When I was breathing I would focus on a spot in the ground
22
49,50 -->
020
22:54,70 and the breathing was keeping me more stable.
22
54,70 -->
020
22:58,34 >> Did you actually feel more stable?
22
58,34 -->
020
23:00,71 >> I did, yes. >> You did.
23
00,71 -->
020
23:03,71 So let's see. Well, what you feel
23
03,71 -->
020
23:07,28 is very important. And I don't want to claim that
23
07,28 -->
020
23:09,78 the machine is right and that you are not.
23
09,78 -->
020
23:12,25 So what you feel is very important.
23
12,25 -->
020
23:14,52 I'm trying to use machines as a way people can communicate
23
14,52 -->
020
23:16,62 with each other. Because I can take this computer
23
16,62 -->
020
23:19,39 and show it to someone else, and have somebody else stand
23
19,39 -->
020
23:21,73 and we can compare it. It's harder, I have found,
23
21,73 -->
020
23:24,73 to communicate feelings. All right.
23
24,73 -->
020
23:28,40 Let's look at what we had here. So you were run number 12,
23
28,40 -->
020
23:31,37 and on force plate number one. We'll look at the parallel
23
31,37 -->
020
23:36,21 force. We get this stuff, and so it was
23
36,21 -->
020
23:45,02 at about 30 seconds that I asked you to just stand there.
23
45,02 -->
020
23:47,26 Well, we don't know, we don't know.
23
47,26 -->
020
23:49,96 So I'm going to take from 30 to about 50.
23
49,96 -->
020
23:55,20 Take that 20-second period. And we'll look at the
23
55,20 -->
020
23:58,40 fluctuations, the technical name is the standard deviation.
23
58,40 -->
020
24:02,37 So this is like the wobble. It was.03 standing on one leg
24
02,37 -->
020
24:05,94 in that crazy pose, then your balance is still
24
05,94 -->
020
24:08,34 really good. All right.
24
08,34 -->
020
24:10,81 Now let's see how that compares with the next.
24
10,81 -->
020
24:14,42 Starting at 60, so this, let's see what yoga does.
24
14,42 -->
020
24:20,42 From 60 to, we'll say 80. And then we have the same.
24
20,42 -->
020
24:22,46 All right. So let's blow this up
24
22,46 -->
020
24:26,59 on the scale a little bit. So we can make sure that it
24
26,59 -->
020
24:29,60 looks the same to our eyes, too.
24
40,04 -->
020
24:42,84 Is there any obvious change at 60 seconds, that's when you
24
42,84 -->
020
24:45,21 started doing the yoga. I didn't actually see any change
24
45,21 -->
020
24:48,65 at that point. All right.
24
48,65 -->
020
24:51,49 So, it's inconclusive. It doesn't show a change
24
51,49 -->
020
24:56,22 one way or the other. So, an inconclusive experiment
24
56,22 -->
020
24:58,89 doesn't mean it's a wrong experiment, but we didn't
24
58,89 -->
020
25:01,73 actually learn anything. >> The breathing might be
25
01,73 -->
020
25:05,83 a personal preference, a personal thing.
25
05,83 -->
020
25:10,04 >> So yeah, the only thing I know of that we might do
25
10,04 -->
020
25:12,97 is ask for you to try something more challenging.
25
12,97 -->
020
25:15,01 >> Okay. >> Well, I don't know.
25
15,01 -->
020
25:17,01 I don't want to challenge you too much.
25
17,01 -->
020
25:20,38 What would be-- >> I have trouble putting
25
20,38 -->
020
25:22,58 my arms up in that pose, I can try that.
25
22,58 -->
020
25:24,75 Compared to a different arm pose.
25
24,75 -->
020
25:26,82 >> Would you be willing to try that?
25
26,82 -->
020
25:28,89 Great. >> Should I do the first 30
25
28,89 -->
020
25:31,56 this is what I'm comfortable in and then going up
25
31,56 -->
020
25:34,73 in the second 30? >> What I want to see
25
34,73 -->
020
25:38,57 is what yoga does. So if you can try and stand in a
25
38,57 -->
020
25:42,47 difficult pose without doing the yoga stuff and we'll take data
25
42,47 -->
020
25:45,81 on that, and then allow you to prepare the proper way,
25
45,81 -->
020
25:47,98 the way you are used to, the way that makes you feel
25
47,98 -->
020
25:50,18 more relaxed, and we'll see what that does.
25
50,18 -->
020
25:59,09 Tell me when you're ready. >> Okay, ready.
25
59,09 -->
020
26:01,76 >> All right. So that's the, that's the
26
01,76 -->
020
26:05,66 difficult challenge, that is quite a challenging pose.
26
07,90 -->
020
26:12,10 I'm going to ask you to hold that for 10 more seconds.
26
13,67 -->
020
26:18,64 Five more seconds. All right.
26
18,64 -->
020
26:22,41 You can go ahead and step off. All right.
26
22,41 -->
020
26:24,85 Now, are you ready to do what you need to do
26
24,85 -->
020
26:27,08 to get into that pose? The way that you are comfortable
26
27,08 -->
020
26:29,38 with? Using the breathing and then let
26
29,38 -->
020
26:33,52 me know when you are there. >> Okay.
26
41,03 -->
020
26:46,13 All right. >> We are at 48 seconds now.
26
46,13 -->
020
26:49,14 Just keep breathing.
26
56,58 -->
020
26:59,21 Okay, and that's 15 seconds through that.
26
59,21 -->
020
27:04,89 ( inaudible ) Well, I wonder why.
27
04,89 -->
020
27:10,33 So, we'll get rid of run 12, we don't need that anymore.
27
13,83 -->
020
27:19,43
So here was the yoga stuff was from 48 to 1
03,
27
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020
27:24,27 that's about there. All right.
27
24,27 -->
020
27:26,84 Again, that's.03 standard deviation, it might be just a
27
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020
27:30,65 limit of resolution of this device.
27
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27:37,09 And then the first part was from 10 to about 25.
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27:40,22 All right, so I can't tell a difference.
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27:42,62 I cannot tell a difference in that pose.
27
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27:45,13 Well, we gave it the good scientific try and that's the
27
45,13 -->
020
27:50,03 sort of thing we do here at the yoga research labs we have here,
27
50,03 -->
020
27:53,00 we try to figure out what exactly is happening when people
27
53,00 -->
020
27:56,71 go into yoga, so we can communicate it, because it's
27
56,71 -->
020
27:59,67 difficult sometimes to communicate a feeling you get.
27
59,67 -->
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28:02,01 All right. Chloe, thank you very much
28
02,01 -->
020
28:04,35 for helping us out. Well, I see that I have just
28
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28:07,68 about run out of time with what I wanted to say.
28
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28:11,82 Let me just finish by saying that people who have good
28
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28:17,19 balance or when the yoga teacher asks you to balance in the pose,
28
17,19 -->
020
28:19,79 you can think of that, you can measure it, if you had
28
19,79 -->
020
28:23,00 a force plate as minimizing the fluctuations in the ground
28
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28:28,20 forces. When a yoga teacher says
28
28,20 -->
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28:34,11 maintain integrity of the pose, that also requires
28
34,11 -->
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28:36,58 this to happen. I haven't had time to talk about
28
36,58 -->
020
28:40,15 integrity of the pose, but that means that you are not moving
28
40,15 -->
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28:44,12 in the middle somewhere, that if you stand in that pose that you
28
44,12 -->
020
28:47,49 demonstrated for us, this outstretched pose, if someone
28
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020
28:50,96 were to press sideways on your hand then your whole body
28
50,96 -->
020
28:54,83 would swing around. That would mean that you have
28
54,83 -->
020
28:58,17 integrity, the whole thing is connected.
28
58,17 -->
020
29:00,67 And work within the pose, I think maybe Phil did that a
29
00,67 -->
020
29:07,08 little bit for us, when you are capable of standing in a pose
29
07,08 -->
020
29:11,81 and then tensing a lot of muscles but not actually moving.
29
11,81 -->
020
29:13,98 So you can't tell just by looking at someone whether they
29
13,98 -->
020
29:17,22 are standing with their legs relaxed as mine are now, or
29
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020
29:20,72 their legs tensed with all the muscles tensed as much as
29
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020
29:24,23 possible, which is what I'm doing now.
29
24,23 -->
020
29:27,50 The outside form doesn't change very much so you can work within
29
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020
29:32,57 the pose, maintaining your equilibrium without actually
29
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020
29:35,54 moving. By doing good work within the
29
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020
29:38,81 pose you improve your stability. Finally, the last one,
29
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020
29:41,08 press your feet into the floor, apparently that depends on the
29
41,08 -->
020
29:43,58 yoga teacher. I've had people come up on the
29
43,58 -->
020
29:46,38 force plates and when I tell them to do what your yoga
29
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020
29:51,19 teacher tells you to do, to press your feet into the floor,
29
51,19 -->
020
29:54,36 they make the sideways forces go to zero, as if they are
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020
29:57,49 standing on ice. Others don't.
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30:01,13 I conclude there is not one uniform standard among all yoga
30
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020
30:05,07 teachers for what they want you to accomplish in the pose.
30
05,07 -->
020
30:07,07 All right. Well that's all we have time
30
07,07 -->
020
30:09,34 for tonight. I'm Jim Reardon, this has been
30
09,34 -->
020
30:11,54 the physics of yoga. Thanks a lot for coming to
30
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020
30:15,58 Chamberlain Hall on this evening to try to do some laboratory
30
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020
30:18,35 work on yoga. Good luck in your practice, good
30
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30:22,35 luck in your physics classes.
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