Before I can dive into the martial arts and how the science
applies, I need to at least introduce some concepts from physics. If any of this sounds completely confusing to
you, then you may want to find an alternate source to get a deeper
explanation. I recommend
khanacademy.com. The following text is a
bit dry for the typical martial artist.
So, you can skip it if you want, but you may need to come back to
understand later articles.
Displacement,
Velocity, and Acceleration
Displacement
(which is like distance and will be treated as such in most situations here) is one of the fundamental concepts in
physics. Space exists. Displacement is the measure of how far apart two
points in space are. For example, “that
punch missed me by 3 inches”. Here, “3” would be the measure and “inches”
would be the unit of measure.
What happens when we put time
in the mix? When we go a distance over a
period of time? Then we get velocity (which is like speed and will
also be treated as such in most
situations here). For example, if a
person runs 100 meters (m) in 12 seconds (s), then their (average) velocity is
100m/12s = 8.33 m/s. In general, the
units for velocity are distance divided by time (distance/time).
Most people are familiar with the standard of testing an
automobile’s “0 to 60” time, which means “the amount of time it takes a car to
go from 0 mph to 60 mph”. Just like
velocity was a difference in displacement
divided by time, acceleration is a
difference of velocity divided by
time. So, a car that goes from 0 mph to
60 mph (note that ‘mph’ means miles/hour, which is distance divided by time) in
5.2 seconds has an acceleration of (60mph – 0mph)/5.2s = (26.8224m/s – 0m/s)/5.2s
= 5.16m/s2 = 11.54mph/s. The
whole “seconds squared” unit is sometimes hard for people to grasp. So it helps to think of it this way: the car
can increase its speed by 5.16 m/s per second.
For those of you who know calculus, acceleration is the
derivative of velocity, which is the derivative of displacement (all with
respect to time).
Force
No, I’m not talking about Star Wars or “force fields” (well
technically…oh nevermind). I’m talking
about physical forces. Gravity is a
force. Atoms are held together by
various forces. Pushing someone involves
applying a force. This is something that
is highly applicable to fighting.
According to Sir Isaac Newton, force (commonly depicted with
the capital letter ‘F’) is equal to mass times acceleration, or more
succinctly: F = ma. Much like distance,
mass is another fundamental measure of the physical universe. It specifically measures the amount of matter
an object has. Note that this is
different from “weight”, which can change depending on the force of gravity
(like on the moon). I also want to
highlight the importance of this concept by pointing out that the formula, F =
ma, is the second of Newton’s three laws of motion (the first being inertia and
the third being that every action has an equal but opposite reaction).
Vectors
Early, I said that displacement was like distance and
velocity was like speed. Vectors are
what make them different. Distance and
speed are known as “scalars”. They are
represented only by a single quantity (5 meters, 55 miles per hour, etc). Vectors, however, are represented by two quantities: magnitude and direction. So, 5 meters might become 5 meters to the
left. 55 miles per hour might become 55
miles per hour North.
Understanding the concept of vectors is extremely important for
fighting. As you may have guessed,
forces are vectors. We don’t just push
people. We push them in a direction.
Conclusion
I realize that all of that text was really light on the
fighting and martial arts, but just like studying any subject, you need to
understand the vocabulary and base concepts before you can absorb any of the
really good stuff. The next post will be
juicier. I promise!
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