[MUSIC PLAYING] We’ve seen how we can use
engineering to communicate with athletes and coaches. And we’ve seen how we can take
measurements of sports without disturbing it. But what we could model
a whole sport from the equipment, to the elite athlete,
to the environment, and even to the rules? Well, we’ve been working on a
grand unified theory, not of gravity and quantum mechanics,
but of something much closer to home. [MUSIC PLAYING] Constructing a grand unified
theory of a sport is about painting the whole scientific
picture. In tennis, we look at the
friction between the surface and the player’s footwear. And there are many properties of
the racket that we measure and model– the strength and balance of the
frame, the string tension and elasticity, the impact point
and swing speed, and how the racket imparts
spin to the ball. For the ball itself, we look at
aerodynamic drag and lift, spin and movement vectors, how
it bounces, and how all of that is affected by atmospheric
factors like humidity, pressure,
and wind speed. We could even look at reaction
times in the biomechanics of the players using motion
tracking and 3-D modelling to analyse how they move and slide
on the surface, and how their perceptions affect
their play. We combine these sorts of
factors to make one overarching computer
simulation– the grand unified theory
of tennis, Tennis GUT. Now we can change any
of these variables. We connected them all together
and they’re all here in this laptop. If I run one of my simulations,
here I’m solving my models individually. And here we have 120 mile-an-hour serve at Wimbledon. You can see the ball reaching
the baseline there. Now what I can do now is, I can
make a change, and we can look at verifying some
of the anecdotes that players come up with. So if I look at playing
the same tennis shots at 3,000 metres– at, say, Mexico City. Well, one of the things that
players say is that the ball arrives much, much quicker
at the baseline. So we can use the model
to test that theory. And here we have
the two shots. The red one is Mexico
City, and the blue one is at Wimbledon. And you can see that the shot
at Mexico City arrives much quicker at the baseline. And the reason for that is
because the density of the air has decreased, allowing the
ball to fly faster. The consequence of that is,
there is actually a ball for playing at altitude to readdress
that balance. Any mathematical model
needs to be validated experimentally. And we’re here in the
laboratories of the international tennis
federation. And here I am with Dr.
Stewart Miller. And we’ve helped you over the
years develop a few machines. And here’s a racket power
machine which is there to mimic the serve of a player. It’s been a bit of a beast
to get working. And it hasn’t always worked
how we wanted. Now, why would we even want
a machine like this? Because of the way in
which tennis racket technology is changing. For many, many years all rackets
were the same size. They with 27 inches long
and 9 inches wide. But when Howard Head found that
you could make rackets out of different materials
that were bigger, longer, wider than the old wooden
rackets, then the ITF decided that it’d better write some
rules for tennis rackets. So we’ve got a rule for the
rackets, and then sometimes other things come up, like
spin, for instance. So what expense have
we got for that? Once you’ve found out how the
ball comes off the rackets in terms of speed, you need to know
the amount of spin that’s generated as well. And this device here allows us
to quantify the amount of spin that different rackets
and string combinations can generate. So we’ve got spin, what next? Well, then we need to know how
that spin affects the flight of the ball through the air? So that means we go to
the wind tunnel? Indeed. Lead on. Wow, I’ve forgotten how
beautiful this thing is. It’s like a space shuttle, or
a rocket, or something. So if we open up the working
section here, right, so we’ve got our ball on a little
axle here. So, it’s a while since I’ve
looked at this, can you remind me of the specifications
of this wind tunnel? It simulates the aerodynamic
affects and measures those aerodynamic characteristics for
balls travelling up to 160 miles per hour, which is just
a little bit faster than the fastest serve that’s
ever been recorded. It also allows us to spin the
ball at speeds of up to 6 and 1/2 thousand revolutions per
minute, which is just a bit faster than the fastest
spin rate that’s ever been recorded. So that means, with this device
we can simulate just about any tennis shot that
can be generated. Now, the spin rate has gone up
since we first developed this. So that’s changed. What other things might
change in tennis? Well really, we’re not sure
because that’s in some ways up to the manufacturers. But what we can do through these
experiments is assess the effects of those changes. And when we put them together in
Tennis GUT, that allows us to predict what might happen in
the future and to protect the nature of the game. The grand unified theory is
just a model of reality. And we can use the physics to
understand what is going on. Equipment manufacturers would
love to get their hands on the model, but the ITF is using
it to preserve the balance between the tradition and
technology within the game. Now Tennis GUT has shown us the
way forward, and we can use the same modelling
techniques and the way its used for any sport.

Dennis Veasley

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