dozen live broadcasting cameras are
pointing at your face the television
host is just about to ask you the first
question and your heart is pounding in
your chest you stop for a moment and ask
yourself how on earth did I end up here
this was us – a few months ago we were
two high school students supposedly
proving NASA wrong in our final final
science project about the aerodynamics
of model rockets so what exactly did we
examine what we looked at was the
so-called drag coefficient of a mile
rocket the drag coefficient describes
our aerodynamic and Arbutus is heavily
dependent on the shape of the object the
drag coefficient is found in the so
called drag equation where CD is the
drag coefficient larger this number is
the greater is their resistance and the
lower this number is the weaker is the
air resistance so in short to make a
rocket fly higher and faster you want a
low coefficient and what we found was at
the NASA’s official webpage they stated
and I quote a typical value for the drag
coefficient of a mall rocket is point 75
and we thought this can’t be true if we
put this into perspective consider a
streamline sports car where the
designers have tweaked and changed every
millimeter to perfection to make the car
go as fast as possible what does it have
point 25 now consider a ball you can
throw a ball but isn’t very aerodynamic
what does it have point 15 so hang on
since point 50 is less than point 75
that would mean that a ball something
that is short and compact would be more
aerodynamic than a rocket some of that
is long and thin and designed to travel
through air that doesn’t make any sense
no it doesn’t and here comes to mind
puzzling part we know something we know
another object it has a drag coefficient
of around point 75 and that object is a
trash can absurd it doesn’t make any
sense so we wanted to determine the real
number for a drag coefficient of a mile
rocket so let’s say a car company wants
to determine the drag coefficient of the
new car then you have a huge wind tunnel
they put their car in they blow in that
a certain speed and they measure that
drag force that I’m plugging into the
equation and bam they get a number
that’s easy so of course we wanted to do
this for their model rockets that we
built so we called Volvo’s just around
the corner and we asked them hey we’re
two science students we’re doing a
project could we use your wind tunnel no
but Chalmers they have a wind tunnel
right yeah they do so we called Chalmers
up and asked hey we’re two science
students we’re doing a project could we
use your wind tunnel no so we had to
think again and we know that when
something is falling it’s accelerating
you to pull of gravity and that’s this
object picks up speed the air resistance
grows greater and greater and eventually
the air resistance will be just as great
as the pull of gravity and it reaches
its terminal velocity and the terminal
velocity is directly connected to the
drag coefficient if you know one you
know the other so if we could determine
the terminal velocity for rockets we
would be good to go but in order to
achieve terminal velocity you would have
to drop them from a height of a couple
of kilometers and there will be crashing
down and crazy speeds not very practical
but we figured the acceleration on the
rocket would changed throughout the fall
and if we only could measure how the
acceleration changed at the very
beginning of the fall we could then
calculate what it would be at the very
end and how do you measure acceleration
with an accident if we had an actual
rahmanir we could do all this we have
solved the problem so we were on our
tutor and asked do you have an
accelerometer no so in the end what we
did was since we couldn’t afford an
accelerometer is we made our own
we bought two small chips we solved them
together we wrote this software in order
to make it lug the data and we could
then put this inside our Rockets and
then we needed a place to drop them
preferably inside and we found a place
here in Gothenburg where we could drop
them from the 8th floor
well then Simon and I we got there and
Simon was quite quick to say Carl it’s
better if I’m upstairs you’ll be
downstairs so then he took the Rockets
you went into the elevator you rode up
the eight stairs you got out he then
carefully looked over the edge you took
one of the Rockets he inserted it in
this mechanism we built in that stood
back you have three two one and he
pulled the wire and the rocket fall fell
and there eight floors down I stand with
an old bedsheet trying to catch these as
they’re falling down they have a speed
of about 80 kilometres an hour and we
did this 20 times and we also dropped
the ball a Poli might wonder why would
we drop a ball but since we came up with
this method ourselves we’re to validate
that it worked and since and since we
know what a ball should have we know
that if our method yields the same
results
we know that our method is correct so we
analyzed our data and we came to some
interesting results
from for the ball we should have point
15 we got point 54 which is very close
and for our Rockets which NASA claimed
should have point 75 we got point 13
which is much more reasonable and with
this product we took part in a national
science competition for young science
products and we actually won the
competition and our prize was to compete
in the world’s largest competition for
young science projects in Phoenix
Arizona against students from 70
different countries from all around the
globe so just before we’re going to fly
to America that’s when we’re interviewed
on the national morning show on TV and
we were nervous than we were but we were
not close just nervous as we were a few
days later it was at the competition in
the US it was judges day which meant
judges were walking around looking at
the projects and interrogating you and
we managed fine throughout the day I
went to write but at the end of the day
we saw one judge walking down the aisle
he had a shaved head was wearing a blue
shirt with a big NASA logo on his chest
he suddenly stopped he saw our title it
said could NASA be wrong in giant
letters he then crossed his arms and he
walked up to us and said alright guys
what are we wrong about so the NASA
engineer was skeptical at first but
after a short time he too was coming
with he too was convinced that the
number was strangely large so we looked
at our poster at the reference source
for this number and he took ups his iPad
and logged on to some NASA network and
soon enough he gave us the professional
email address to the very person who’s
responsible for our number and so
excited we were a year’s work hundreds
of our about this tiny number we wrote
an email we attached our study and we
click that send button and quite soon we
got a reply sorry the email address is
not found so where does this leave us we
have a substantial amount of data that
test that something is wrong with nasa’s
number the web pages where this
information can be found has been
virtually untouched since the guy who
wrote them retired no one seems to be
picking up where his work left off and
this at this point you might ask why
does it matter it’s just a tiny
insignificant number that no will notice
but no this number is constantly being
quoted all around the web everyone
interested in rocket building refers
back to this page and as far as we can
tell no one is questioning it because
it’s NASA this is the Bible of rocketry
but we not only question the number we
set out to find the real answer if
something seems wrong to you with the
information you’re being fed then stand
up and question it even if you have next
to no resources like us our research
produced a different result than what
the accepted truth is and someone’s got
to be wrong and between you and us we’re
pretty sure it’s NASA
[Applause] [Music]
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