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[Music]
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hey Cassie look the Perth Australia Day
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fireworks show you know I love Fireworks
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the way they go up into the sky and then
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explode with a burst of color and light
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you know what let me tell you and the
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audience watching about fire
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[Music]
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Works loud bangs were first produced in
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China around 200 BC the Chinese
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discovered that by heating bamboo the
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air pockets within the stem would expand
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and eventually blast outward making a
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loud noise
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they soon discovered black powder to
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make the explosions even
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[Music]
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louder of course as with all
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technological advancements the military
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soon took control of gunpowder in the
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13th century devices such as bombs
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exploding arrows cannons and guns slowly
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spread through China Arabia and Eastern
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Europe the European Rene hunt however
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created the first true fireworks using
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black powder for enjoyment rather than
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War well it may seem relatively simple
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to go Chuck a bunch of chemicals
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together light a fuse and then take
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cover it's actually quite a complex
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process which allows fireworks to launch
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explode into shapes and then fill the
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sky with color and I think it's
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fascinating H cast produced by the
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burning gunpowder is forced out of the
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bottom of the device making it
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accelerate upwards the biggest fireworks
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can reach Heights of up to 400 m and
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from here they can be seen over 80 km
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away it's pretty
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impressive Hot Gas blasting out of the
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back of a rocket only allows it to reach
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such astonishing altitudes due to
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Newton's third law of motion 300 years
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ago the English physicist wrote that for
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every action there is an equal and
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opposite reaction you can see examples
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of this with the recoil of a
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[Music]
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cannon this means that as the rocket
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pushes on the exhaust the exhaust pushes
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back on the rocket making the rocket go
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up as the gas goes down without needing
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any moving
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Parts launching the firework is only one
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part of the system however a second fuse
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located inside the firework itself is
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set to ignite a second Reservoir black p
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powder this one is set to explode
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outwards and contains the components
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which create light these are known as
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fireworks stars and they are essentially
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concentrated
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sparklers these stars are made to blast
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out in a variety orientations to create
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a multitude of shapes this can range
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from simple round shells to more complex
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Stars and Hearts the shapes are actually
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quite simple to produce although much
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harder to create are the explosives
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Styles themselves I'm going to break
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them down into how we get the light and
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then how we color
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it firstly getting the light in many
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respects a fireworks star is simply a
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bigger version of a sparkler the same
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ones which you can buy from any shopping
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center the mixture that makes up
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sparklers is comprised of a fuel and an
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oxidizer metal powder is added to
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produce the color we see but we'll go
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into that
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later the fuel of a star consists mainly
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of charcoal the star needs to burn
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bright and fast so it simply can't get
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enough oxygen from the air to do this
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instead an oxidizer is used which
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provides a concentrated source of oxygen
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in this case we're using potassium
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nitrate so how concentrated exactly well
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here is a pretty cool demonstration
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we've got a bunch of sparklers and we're
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going to tape them up and drop them in
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the
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water
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water and sparkles don't usually mix
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what will happen when we put tape on
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[Music]
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it to see that it's burning underwater
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so we've now got the basic idea let's
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try it with a few more
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sparklers
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[Music]
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so that's really cool fire Underwater
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All Because Of
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oxidizers so we've got to fuel an
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oxidizer to produce heat but if we want
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to have light as well then we're going
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to need to add some metal shavings over
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time people found that by adding
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different metals to fireworks they would
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burn a different color lithium compounds
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burn Red Copper Blue by adding different
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metal salts in different in ratios the
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specific color of fireworks can be
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selected so we know that different
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Metals produce different colors when
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they're burned but why is this so for
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that we need to enter the realm of the
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atom and the most complex field of
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scientific research to date quantum
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physics in order to understand what's
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going on inside an atom to create such
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consistent light we're going to first
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need to understand what an atom is and
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an atom is the smallest unit of a
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chemical element for example a water
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molecule H2O is made up of two hydrogen
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atoms and one oxygen atom the atom
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itself is made up of three basic
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particles positive protons negative
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electrons and neutral
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neutrons the protons and neutrons reside
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in the atom Central nucleus and account
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for nearly all of the atom's mass the
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negative electron are attached to and
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orbit the positive
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nucleus every atom has the same number
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of protons and electrons so that the two
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different charges balance each other
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out now this gets interesting when you
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look at where the electrons are orbiting
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electrons orbit only at very specific
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distances from the nucleus which are
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defined by the wave nature of the
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electron you
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following now this is easy enough to
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understand when you have electrons
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orbiting the nucleus at their lowest
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energy State they fill up the lower
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shells first and then the next and so on
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you can see this pattern where you
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compare atoms with steadily increasing
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numbers of protons and
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electrons if we exite an electron by
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heating it the electron responds by
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jumping up an energy level but since the
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electron can only ever be found at a
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specific level we run into a bit of a
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problem the particle has to get from A
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to B but without traveling through any
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of the space between them and it has to
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do this
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instantly by performing a Quantum Leap
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the electron is able to jump between the
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levels without ever passing through the
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space between them as strange as this
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may seem it's been backed up by every
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scientific test to date quantum physics
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is our best scientific theory
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yet when the electron stops being
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excited it jumps back down the shells
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again performing another Quantum Leap
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due to the law of conservation of energy
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by dropping down the energy levels the
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electron emits some electromagnetic
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radiation a photon of light the
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frequency of the slide is directly due
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to the nature of the electron jump since
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all atoms of an element are exactly the
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same when many billions of these leaps
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occur every second together they can
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produce enough photons to be detected if
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the radiation produced is of the right
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frequency then we can see this as
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light medals perform this lead
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exceptionally well each when heated
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producing a different frequency of
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electromagnetic radiation it just so
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happens that a select few of these are
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incandescent in a Range that we can
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observe as being different colors when
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added to a firewor star we see the
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colors of physics painted upon a black
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canvas of the
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night all fireworks are just variations
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upon these same basic principles
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firework makers can mix and match to
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create the perfect effects for the most
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spectacular of
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fireworks from a bamboo bomb to Rocket
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propellant underwater fire to the
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quantum realm fireworks are truly a
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remarkable creation of the human race
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it's 3,000 years of human history
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bringing you a spectacular from the
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quantum realm next time you look at add
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the light to the sky remember
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[Music]
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[Music]
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that
