   - Welcome to orientation,
   Vault Dweller.
 In today's lesson, we'll be
 going over defending yourself
   in a world after complete
   nuclear annihilation.
   You might need to vaporize
   some people or things,
  so let's make sure that you
  at least know the science
  of what's going on.
   (upbeat electronic music)
   So, Vault Dweller,
I'm sorry, I can't
talk like that anymore.
   So, Vault Dweller,
   I'm sure that you're eager
   to get back out there
  into the Wasteland,
  and to vaporize some raiders
as you see right there,
  But we should at least have
  some kind of understanding
of the physics of the
laser and energy weapons
 in "Fallout" before we do so.
  First, what does
  "vaporization" really mean?
There's a big difference
between separating all the atoms
in a person's body and
reducing them to a pile of ash.
   First of all, atomic bonds
   are really hard to break.
   Consider a water molecule
   with one oxygen atom
and two hydrogen atoms.
   To break the bonds between
   the oxygen and hydrogen
   of just 18 grams of water,
you would need to input
 920 kilojoules
of energy, or about the
same amount of energy
 in the form of work
 that it takes to stop
  a small car speeding
  down the highway
  at 60 miles an hour,
   or the amount of energy
   that comes from blowing up
  half a pound of TNT.
If energy weapons were
separating all the atoms
  in a person's or
  supermutant's body,
  then it would take a
  gargantuan amount of energy,
  3,000,000,000 joules of it.
   That's the same amount of
   energy you'd have to input
to melt 5,000 pounds of
steel or power armor.
 But let's dig into that number
 a little bit like a mole rat
  to see where it comes from,
because most of the energy that
goes into vaporizing someone
  is spent vaporizing
  that person's water.
A pile of ash is devoid
of water content,
so energy weapons must at least
be vaporizing all of that.
 If the average person
 is, maybe, 70% water
and weighs 78 kilograms,
then, on the whole, the
average person contains
 56 kilograms of water.
That's what we have to vaporize.
  Time for a chemistry lesson.
 Thinking back to the
 water molecule again,
   we have to break both of
   its oxygen-hydrogen bonds
to totally vaporize it,
and to do that, we have
to insert what's called
 the "bond enthalpy" energy,
 which is the amount of energy
   you need to insert into a
   chemical bond to break it.
 And we know that the
 oxygen-hydrogen bonds
 break by inserting 460
 kilojoules of energy per mole
of these bonds.
  A "mole" is a
  standard measurement
 defined as the number of atoms
 in 12 grams of pure carbon,
   12 which just happen to be
6.02x10
   to the 23rd atoms,
 now known as
 "Avogadro's constant,"
 named after the scientist
 who discovered this constant.
 Now, using this as a
 standard measurement,
if you take the combined
atomic mass of an atom
  or a molecule like
  water and add it up,
  that's how many
  grams of this stuff
 are in 6.02x10 to the
 23rd of that stuff.
  Since hydrogen has an
  atomic mass of roughly one,
and oxygen has an atomic
mass of roughly 16,
   that means that
   the water molecule
   has a combined atomic mass
 of 18,
 yeah (laughs).
  So, that means that in every
  6.02x10 to the 23rd
  water molecules,
  there are 18 grams of water.
   Now, with all that
   chemistry out of the way,
how much energy does it
take to vaporize someone
   like in "Fallout?"
If the average human body
contains 56 kilograms of water,
   we divide this by
   18 grams of water
 per one mole of water
 to find the moles,
   which equals a little over
 3,000 moles of water.
   And in every one of these
 3,000 moles of water,
 there are two
 oxygen-hydrogen bonds,
  remember back to
  the water molecule,
 which means there are
 roughly 6,000 moles
of these oxygen-hydrogen bonds,
 which, remember have
 a bond enthalpy energy
  of 460 kilojoules per mole.
  You see where we're
  going with this.
  So, if you multiply
  these values out,
  6,000 moles
  times 460 kilojoules
   per mole,
  you get a gargantuan
  amount of energy;
   2.8 billion joules
   of energy,
which is like (lightning
crashes) two full
lightning bolts.
 (cash register dings)
   So, there you have
   it, Vault Dweller!
With "Fallout's" energy weapons,
 you're literally carrying
 around lightning in a bottle,
   or microfusion cell,
   ready to vaporize raiders.
 The technology may
 have changed, but war,
  war never changes, except...
 Wait, no, it totally changes.
   Think of the difference
   between dropping one guy,
   dropping a nuclear
   bomb on a city,
  and a bunch of dudes lining
  up on a hill, 10 feet away,
and shooting each other.
Yeah, yeah, war totally changes,
because science.
   Okay, bye!
   (upbeat electronic music)
   Want more science?
  Check out my last video on
  how modern hoverboards work.
 Go back to nerdist.com
 for more videos.
   If you want "Because
   Science" two days earlier
   than anyone else,
  head to Vessel at
  vessel.com/nerdist.
  And, as always, if you have
  any comments or questions,
   or suggestions for
   future episodes,
you can hit me up on the
comment section below.
Thanks!
