How Much Does Your “Ghost” Weigh? (Because Science w/ Kyle Hill)

How Much Does Your “Ghost” Weigh? (Because Science w/ Kyle Hill)

December 7, 2019 100 By William Hollis


– Try something for me. Point to where you are. Point to where you think
your consciousness is, where you’re experiencing the world from. You’re probably all now pointing somewhere
around your head, right? We all feel like we are
somewhere behind our eyes, but we know that all that’s
in there is your brain and not some secret
compartment that holds all your thoughts and fears and desires. What I’m trying to say is that it’s hard to measure where you are compared to where you feel you are. But what if we downloaded
you into a machine body? Then, we might be able to measure you in a different way. In 1995, the seminal anime
film, Ghost in the Shell, posited a world so
technologically advanced, that most, if not all, of the
human body became obsolete. Entire bodies and brains
could be synthesized and only a person’s ghost or consciousness needed to be transferred into it. Technology powered consciousness transfer is an interesting
philosophical and political and ethical thought experiment, but what would actually
transfer to a shell? If I somehow transferred my consciousness into this synthetic brain, would this brain change in some way? Would what I consider
immaterial become material? What would my ghost weigh? In the early 20th
century, a physician named Duncan MacDougall famously reported that immediately after death, one of his patients weighed 21 grams less. And for over 100 years, this
figure has been used by people as the weight of your ghost or your soul, what many people consider to be you. MacDougall’s experiments were
never considered scientific, so now that consciousness transfer isn’t a completely out of bounds idea, I think we can replace this figure with something a lot more grounded. If you are consciousness,
as I would argue, then if someone wanted
to transfer your ghost into a shell, they would
first have to translate all of the information that
is in your brain into data, if that’s even possible, but estimates for how
much data your brain holds range anymore from one
terabyte to one petabyte. And the high end estimate, one petabyte, is like stacking 39,000
64 gig flash drives 250 meters high. We don’t understand consciousness yet, so thinking of it as just simple
data points and connections probably isn’t right. But it’s a start and a way to weigh your ghost. If we wanted to store the
state of your brain right now, then using flash memory, like
is used in solid state drives, wouldn’t be a bad idea because even if your
shell’s power turned off, the state of your ghost would remain. The physics of flash memory
is pretty complicated, but these are the basics. This is your basic flash memory unit. It’s a transistor with what’s called a floating gate right here. Right now, when there’s no charge, your computer would register
this setup in binary as a one, but if you start applying
charge to it at the worldline and what’s called the bitline, electrons are compelled to flow through even this non-conductive material that separates them. However, as they do that,
electrons begin to quantum tunnel and build up at the floating gate, acting to prevent charge from
flowing to the worldline. Once the flow of electrons is
blocked by the floating gate by more than 50%, most of the flow is
going between the source and the drain here and your
device reads it as a zero in binary and that’s
how you get both bits. But if you reverse the
flow at the worldline and the bitline, then all
of the gates are cleared and effectively erases the data. According to quantum mechanics, when electrons are trapped
in the floating gate, when data is being written, they have more energy compared
to when they are not trapped. This is what would give your ghost mass. Back in 2011, Professor John
Kubiatowicz at UC Berkeley estimated that the energy
increase of trapped electrons per bit was one one thousand
trillionth of a joule. And although the total number
of electrons in the system isn’t changing, when some
electrons have more energy, there is technically more mass, thanks to mass-energy equivalence, in a full solid state drive. So, mass-energy
equivalence from Einstein’s E equals m c squared can
estimate the mass increase in a fully loaded synthetic brain with maybe on average half
zeros and half ones for data. Using the high end
estimate of 2.5 petabytes, the mass of your consciousness would be just 100 femtograms. If you’re not familiar with that number, that’s a million times less massive than a grain of fine sand. Almost nothing. We think of ourselves
as heavy fleshy things, but transfer everything
that could be considered you into a Ghost in the Shell style body, and that download
wouldn’t change any scale we’ve ever developed. Using this estimate, the consciousness of every single human being on Earth would weigh less than a single snowflake. Your digital ghost wouldn’t
weigh anywhere near 21 grams, but it would be something, as close as you could get
to a physical essence. So, how much would a shell’s ghost weigh? Well, according to mass-energy equivalence and using something like
a solid state drive, just one ten trillionth of a gram, just the energy of electrons encoding the thunderstorms
of brain activity inside of a collection of molecules resisting entropy futilely. It sounds even more dystopian
than Ghost in the Shell, doesn’t it? Don’t worry. Even if in the future, you
are just ones and zeros, only you will arise from a unique and awesome arrangement of them. Because Science. Thank you so much for watching. Make sure to follow me
on Twitter at Sci_Phile where you can suggest
ideas for future episodes and on Instagram under the same handle where I’m now posting mini-episodes. And a big shout-out to
YouTubers like Vsauce who have also calculated
the weight of data before. It was very helpful, and as always, thanks for watching. In the 1995 movie, the
Major rips her own arms off on top of a tank trying to open the tank. And she could, if she
had a synthetic body, she could totally do that. If her hands just had a ton of grip and maybe she could lock them
like an eagle’s talons do with tendons on their bones, which is super badass
but beside the point, then she could lock
her hands onto the tank and then apply so much
superhuman robot strength to her joints that she
would rip her own arms off although at some point
while they were ripping, they would probably give out, so maybe it wouldn’t rip all the way unless you applied it super forcefully. So, Ghost in the Shell, completely
scientifically accurate.