if it's there hey that was a hard one
because this balls a little bit magic
it's got a bit of string glued to the
left side of it to make the ball curve
to the left why is that and that's
because the air that's flowing from the
front of the ball around to the back
encounters this seam becomes turbulent
and turbulent air is known to stick to
the ball longer than smooth or laminar
flow and so the air is deflected this
way to the right on the ball and
therefore there's a force on the ball to
the left and so it curves so in this is
quite a light ball so it curves a long
way huh but on a cricket ball the seam
isn't on one side it seems down the
middle
correct it's spinning in such a way that
the seams inclined at an angle to the
direction of motion of the ball
in which case air coming towards the
ball will flow smoothly around the
smooth side and separates from the ball
air flowing on the rough side the same
side becomes turbulent as soon as it
encounters that seam gets deflected to
the left mm-hmm
and therefore the ball gets deflected to
the right so you basically make a rough
side using that seam by angling the
scene with a cricket ball the cricket
ball or you can have a rough and a
smooth side because as time goes on
during the game one side gets rougher
than the other the players maintain the
smooth side by polishing it wherever as
if they're scratching themselves right
and then you don't really need the same
to have that effect because the effect
is just a rough side and a smooth side
so a bowl always swinging towards the
rough side it does but how does someone
swing a baseball then that relies on the
Magnus effect normally so if the spin is
about a vertical axis allow the curve to
the left or curve to the right of the
curveball exactly however there's a
pitch ball known as the sky
or the people don't like to know about
because it's illegal and if you're
roughing up one side of the ball
surreptitiously without anybody noticing
and then toss it it will curve a long
way just like the cricket ball it'll
curve towards the rough though correct
however there's an effect discovered
just this year which is fairly obvious
when you think about it you can have a
smooth patch on a baseball but I mean
the seam seems to be symmetric
everywhere so how can you really have a
smooth patch what you do there is to
make sure that access passes through a
spot which is a large distance from the
seam in other words right about there
it's about one inch away from the seam
and if it rotates about that axis then
you've got a big spot that's always
smooth on that side got a smooth spot as
opposed to a rough spot and so it swings
away from the smooth spot it does and I
can show you that in slow motion
ah so you've tried this out with one of
your polystyrene balls I hope say that
you can see the effect more dramatically
but it's also on film from a real
baseball match I in April this year was
filming the notice for the first time
that it's curving their own way
so who was it who explained this effect
late you were the first person to
explain how you can cause a baseball to
swing in the opposite direction
I took an Aussie to show should he go
down now it's done exactly uh-huh
well why don't we yeah why don't we play
a bit of ball but with that thing I
don't think you can swing that as much
icon yeah let's give it a shot okay