Born to do physics

Is anybody else as fascinated as me at how frickin' good human beings are at physics. Not pencil and paper (and calculator) physics. Most people suck hard at that. No, I mean, instinctively, we are unbelievably good at physics. Take swinging on a swing for example. How a swing works is that a force is applied to the oscillating motion of the swing. If the frequency of the applied force is proportional to the frequency of the motion of the swing, the amplitude of the swing increases. In laymen's terms this means that, force is applied at the two highest points of the swing (the peak and saddle point of one cycle). The force applied adds to the height of the swing but since you are applying it to the current maximum height, the swing goes higher. This is a phenomena known as resonance frequency and I can tell you all faithfully that it is a son of a bitch to calculate. We're talking multiple pages of math here and yet young children are capable of doing it.

Swinging isn't something that you can be taught either. Sure adults and kids who have figured it out already will tell you to pump your legs but that doesn't really mean anything. I know, I watched/tried to teach someone roughly my age how to swing just this past summer. It's not possible, you have to feel how to swing. You have to figure out, in your head, without any solid calculations, the exact points where to apply force to maximize amplitude. All of it is completely instinctual and I think that that's frickin' amazing.

Another example: Driving -> espcially in the snow. The force of the car is equal to mass times acceleration. The force of friction is equal to the normal force of the car (mass times gravity) times the coefficient of friction between the tires and the road (clear road will have larger coefficient than icy road). If a car accelerates too quickly, the force of the car will be greater than the force of friction and the tires will spin out (or if you're slowing down too fast, skid). Somehow, instinctively, people can just feel these calculations. I know how fast I can accelerate on an icy road before the tires start spinning... I didn't do the math, I just feel it. So does everyone else. How? How can we instinctively be so good at physics? Is it just simple practice of constantly having to move around in our surroundings every day? Probably.

It gets even more complicated when a car goes around a corner. The force exerted by the car going around a corner is equal to the mass of the car times the velocity squared all divided by the radius of the curve. This is why sharper corners need to be taken slower. The radius is smaller and now the force is dependent on velocity, which moves in a direction tangent to the curve (this is why you move around inside the car while taking the corner. It's cause the car wants to keep going straight) . But somehow, people can calculate this all in their head, they realize without mathematically realizing it that the magnitude of velocity will screw with their ability to not go sliding off the road.

They also somehow realize somehow that acceleration while in a curve is directed towards the center of the circle (if the curve kept going and made a circle). This means that, if you accelerate while in a corner, your ability to stay on the road increases because the force of the car is directed towardsthe center. (don't overdo it though, tangental acceleration factors in here too and, with enough acceleration or low enough friction [ie. snow], you'll get fucked). So, somehow, without actually knowing any of the theoretical pencil and paper physics behind it all, most people still realize that it's best to go into a corner slowly and then accelerate out of it. How amazing is that. Everybody has a fairly frickin' amazing understanding of physics, even if they don't have any idea what a vector is.

Almost everything we do is an example of us doing physics in our head and we're so frickin' good at it. I think that this is pretty damned cool so I thought I would share it.