OK, if you're a regular viewer of What If,
you know we've already explored
the idea of finding silicon-based alien life.
But what if we didn't have to venture
far off into the Universe
to find these lifeforms?
What if you were the one
made of silicon instead of carbon?
Carbon is a bit of an attention hog.
And for good reason.
All life on our planet shares carbon
as its primary building block.
18% of your body is made of carbon.
Without it, you'd have no DNA.
On the other hand,
silicon is one of the most abundant
elements on Earth,
second only to oxygen.
Approximately 25 to 30%
of our planet’s crust
is made up of the stuff.
The potential for silicon-based life
was first suggested in 1891
by astronomer Julius Scheiner.
The hypothesis is based
on the chemical similarities
between carbon and silicon.
Both elements bond with oxygen
to form polymers.
In other words,
large molecular structures.
However, when silicon reacts
with oxygen on Earth,
it forms silicon dioxide.
This solid, also known as silica,
is a key ingredient in sand.
And less naturally,
silicon and oxygen can be found together
in the synthetic compound
known as silicone.
This liquid or rubbery substance
is in everything from electronics
to oven mitts,
not to mention breast implants.
But these silicon-based compounds
can’t support life.
Unless you're talking about
the What If universe.
Even though they have a lot
of chemical similarities,
if human life
was based on silicon instead of carbon,
everything would be different.
While both elements are able
to form double bonds with oxygen,
the bonds formed by silicon
are typically weaker.
That means silicon-based life on Earth
would be simple and primitive.
There's no way that your body
in its current complex form of organs,
bones and tissues, could exist.
Yeah, say goodbye to the human shape
as you know it.
You’d now be a blob of silicon compounds
And not just humans.
Every living thing on Earth
would likely be some kind of blob too.
It would actually be a miracle
that you’d exist at all.
It would also be highly unlikely
for a simple lifeform like you
to be able to successfully reproduce.
You’d be too fragile.
This would be especially important
when thinking about how
this silicon-based life would have begun
on Earth in the first place.
Chemical life needs to exist
in a medium that lets molecules
move around.
For carbon,
liquid water is the perfect medium.
Water can carry things
into and out of the cell.
But water wouldn’t support
the development
of your new human chemistry.
The double bonds of silicon
would break down into single bonds
in the presence of H2O.
That means instead of evolving
into the stellar example of flesh and bone
that you are today,
you'd turn into a silicate rock.
Silicon-based life would need
a different liquid to be
the common binding element of life.
One medium that could work
is sulfuric acid.
That's because the silicon structures
that normally break down in water,
would be more stable in sulfuric acid.
The implications of this
would go far beyond
every lifeform on Earth
being completely different.
Now the whole planet
would be different too.
Not only would life need
oceans of sulfuric acid to spring out of,
the atmosphere would need
a major overhaul.
Silicon-based life wouldn't necessarily
need oxygen.
Because silicon would react with oxygen
the same way it would react with water.
It would turn into a rock.
Temperatures on Earth would also
have to change dramatically.
Made from silicon,
you’d need an extremely
warm environment in order to thrive.
By extremely warm,
I mean unbearably hot.
The melting point of silicon
is 1,410 °C (2,570 °F).
Yeah, in other words,
for this element to exist in any form
other than a solid,
Earth would have to be a very toasty,
very acidic place.
And scattered across it
would be billions of blobs of life
completely incapable of reproducing.
The odds of these blobs evolving
into intelligent life like the carbon you?
Well, sorry to say,
but it appears we’ve wandered
into science fiction territory.
Imagining the possibility
of silicon-based Earthlings
raises many big questions.
Like how did life begin on our planet?
And what conditions are necessary
for life to continue to evolve?
But also what would happen
if things went in a different direction?
Well, whatever the answers
to those questions may be,
life flourished here on Earth the way it did.
And it was the perfect carbon-based recipe
for you to become the human you are.
And who knows?
Maybe life didn’t really originate
here on Earth after all.
Wait, what?
Well, that sounds
like a story for another WHAT IF.