Hey, Vsauce. Michael here. The dog
that played Toto in The Wizard of Oz was credited
as Toto, but in reality the dog's name
was Terry. And when Terry died in 1945
her owner and trainer Carl Spitz buried her on his ranch
in Los Angeles. But in 1958
the Ventura Highway was constructed right
through Terry's grave. Her remains were
disturbed and have never been found. Fifty-three years later
a memorial was erected in Hollywood Forever Cemetery
in her honor but because she isn't burried
there, the memorial is not a grave. It's what's known
as a cenotaph, an empty
tomb. I was reminded of Toto's
cenotaph when I saw the cenotaph of Philopappos, atop the Hill of the Muses
in Athens. You see, I was recently in Greece
talking about YouTube with YouTube creators. The
all seen eye of Guy came along and we visited
the Acropolis, a Lion Gate - nearly a thousand years older than the Acropolis.
The earliest known analog computer. Plenty of beautiful
cats and I even took a selfie in
Delphi. I've seen all of these things and
how old they were, it made me wonder how will we
be remembered.
How will future archaeologists react to the ruins of today's
society they find thousands of years from now.
Will they do a good job piecing it
together? Will anything about you in particular
be remembered? And, for that matter,
how do we even know that the past really happened?
Not just the way we think it happened, but it all.
Seriously, can you prove that the universe wasn't created
last Thursday? That everything - every person, every memory you have,
every photo you've taken didn't just pop in into existence
last week or five minutes ago?
Last Thursdayism is the belief that the universe was created
last Thursday. It doesn't have actual
followers or rituals but proving it wrong
is impossible. Not because the universe
actually was created last Thursday but because Last
Thursdayism is not also falsifiable.
It cannot be shown to be false. In the evidence you bring up against it can be
explained away as part of the
everything that was created last Thursday.
Many people believe that in order for a theory
and explanation to be scientific it must be possible
to refute it, to prove it wrong, to test it.
So, instead, Last Thursdayism falls into the domain
of philosophy, where luckily
there are razors - little rules of
thumb that help shave off unlikely explanations.
The most famous is Occam's Razor. When faced with the choice between
explanations,
choose the one that requires diffused assumptions.
Occam's Razor can shave off
last Thursdayism because it requires
fewer assumptions to believe that, say, this beehive
tomb was constructed way back in the Bronze Age
and that I just visited it later than it does to believe that
the tomb, my memories of it and this footage of me
inside it just happen to coincidentally pop into existence at the same time
last Thursday. One of my favourite philosophical razors
cuts off so much stuff it's not even
called a razor. It's called Newton's
Flaming Laser Sword. It states
if something cannot be settled by experiment, then it is not worthy
of debate. So let's move on
to the past. What does Newton's
Flaming Laser Sword tell us about the past? I mean, it doesn't exist in the same
way
gravity or light or protons do. We can't do experiments on it,
build control groups, run trials. The past
just is what it was.
We will one day be the past and no matter how well we try to record
our stories ourselves, without
time machines future archaeologists are going to have to make a lot of guesses
about us.
But that's kinda cool.
Future humans will likely know way more than us today
about medicine, about exoplanets, about physics.
But one thing they almost surely
will not know more about than we do is
today. Will your great great great great grandkids
know your name? Will aliens, who visit Earth
millions of years after humans leave or go extinct,
understand that Animorphs was just
fiction, and not a history of our people?
You are destined to become whatever the future
thinks you were, if you're lucky.
Vandals, fire, natural disaster,
conquerors, thieves, all of these forces obscure facts
overtime, but no matter how well we tried to preserve
today for future history books, there's one type of
fog we are unlikely to avoid.
Apathy. Ira Glass put it well
when he asked his listeners a simple question: name
10 people from the 15th century.
We have records of more than 10 people but to most of us
they don't matter. In five hundred years
radio host will be making the same jokes but about us.
However, there is a legacy leave behind
that is irreversible. Immutable,
and in a way, unforgettable.
To conserve energy, turn off when not in use.
Or just keep them on. Energy will be conserved
no matter what you do. Even if you leave lights on all year,
there will be no less or more energy in the universe.
What's really being conserved when we turn off lights
are the resources we turn into energy
the lights can use. But if you counted up
all the energy in the system, before and after turning the lights on,
it would be the same. Energy also does something else.
Unless hindered from doing so, energy
will spread
out - it will disperse. That is,
in so few words, the Second Law of Thermodynamics.
It's how our universe works. It's why things that happen spontaneously
do. Energy spreads.
Even when a process locally concentrates energy,
like when a crystal forms or life grows,
the Second Law isn't violated because these processes
aren't independent from the larger world around them. They aren't
100 percent efficient. Hindrances can hold back the inevitable spread of energy for a
long time. The Second Law doesn't say
when energy will disperse - just that when it can,
oh it will. Balloons will deflate,
objects will fall, hot objects will cool down,
and perfume sprayed across the room will eventually migrate to your nose
even in really still air. How much
or how widely energy has spread out is measured
in entropy. Entropy is often called
"disorder", "chaos". But entropy is very different from macroscopic
messiness. This deck of cards is
themed after Greek philosophers. It's also arranged by
value and suit - the entire deck. But if I take the deck
and shuffle it, that is, disorder it, I haven't
actually increased the deck's
entropy,
because nothing about this deck of cards'
energy is different than it was before. However,
entropy in the greater world around us
has increased because in order to shuffle the cards
my body has to do work. It has to take energy concentrated in my cells
and change and disperse that energy into kinetic energy,
movement, and a little bit of heat from my body and from the cards,
friction, and a little bit of sound energy - that rustling noise.
So there's your real legacy.
Your contribution to the universe's growing
entropy. No process will be able to
undo the net increase in entropy
you accomplish in your life. History may forget you,
or misinterpret your accomplishments, or what stood for.
The ripples you leave behind may get redirected
but the universe will never be able to forget the
entropy you add. That's the law.
The Second Law of Thermodynamics.
Many scientists believe that this means that eventually
energy - heat - will be completely spread out
evenly throughout the universe. It will be the same temperature
everywhere, and at that point nothing will be able
to happen. Because in order for something to happen
entropy needs to increase, energy needs to spread, the move to change.
This may be the ultimate fate of the universe -
thermodynamic equilibrium. The
"Heat Death" of the universe. It's been estimated that at the rate things happen
this end the universe will occur in about
8 googol years, and you're contributing to it
by simply existing. A funny consequence of all this
is the fact that people who aren't very active, people who don't do much but lay
around
aren't just being lazy. In a way
they're being considerate. Sloth
maybe of vice, but to the universe
it's a fountain of youth. Choosing to do as little as possible
means consciously limiting your contribution
to the inevitable dispersal of energy and thus
in a teeny-tiny way postponing
the "Heat Death" of our universe.
Relaxing adds time
to the universe's life: in amount of time, to be fair, almost indistinguishable
from zero,
but still theoretically real. Being
lazy will make the universe last
longer. So thanks for
chilling out. Thanks for taking it easy. And, as always,
thanks for watching.