January 24, 2023 • 38 mins
Nature abhors a vacuum… and so do we? In this episode of Stuff to Blow Your Mind, Robert and Joe discuss the subject of horror vacui as it relates to philosophy, physics and the arts.
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of My
Heart Radio. Hey you welcome to Stuff to Blow your Mind.
My name is Robert Lamb and I'm Joe McCormick, and
we're back with part three of our series on Horror
VAKUI or Fear of the Void, which we have We've
(00:25):
been mainly focusing I think on like art and design
in the past couple of episodes, but today I wanted
to take a look at the history of the vacuum
and specifically resistance to the idea of the vacuum in
philosophy and physics. And to begin, I was reading about
the scientific history of vacuum physics in a book called
(00:48):
The Void by Frank Close from Oxford University Press in
two thousand seven. Frank Close is a professor of physics
at at Oxford I think emeritus now, But anyway, I
was reading about this and he included a quote from
the rig Veda that I thought was very interesting. This
is from the creation Hymn of the rig Veda, which says,
(01:09):
in translation, there was neither non existence nor existence. Then
there was neither the realm of space nor the sky,
which is beyond what stirred where and I really like
this because it I think it encapsulates a kind of,
uh a fascinated but challenging history of attempts to conceptualize
(01:34):
empty space, to even imagine what empty space would mean
if it were to exist. Because I noticed kind of
a gap here. As far as I can tell, most
people all around the world today, even in various you know,
different cultures, whatever, really, as as far as I can tell,
don't seem to express any major problems making sense of
(01:56):
the idea of empty space. Obviously, there's a lot we
don't know about the nature of space. What is space,
where does it come from, what different kinds of space
could there be, and so forth. So space is still
a vessel of many mysteries. It's not like we've got
it all solved. But if you just simplify the idea
to the basics, I and I think most people don't
(02:18):
have any problem imagining the concept of an area of
three dimensional space with no particles in it. That just yeah, okay,
that that makes sense as an idea to me. But
if you read about how ancient Greek philosophers wrote about
this question, I do not get the impression that the
same was generally true for them, not only did many
(02:40):
of them deny the possibility of empty space existing. Sometimes
I get the feeling that they are struggling to even
imagine what the concept would mean. Do Do you know
what I'm getting out here? Rob, Yeah? Yeah, this, Um,
this is something we talked a little bit about off
my before the the episode here. Um it's it's it's
(03:00):
it's kind of complicated. I mean at one level, yeah,
they're They're always going to be linguistic possibilities in play.
For example, I was looking into some sources on the
void in Chinese philosophy and you run into, for example,
that they're separate terms for such concepts as emptiness, nothingness,
and the infinite or the absolute and and one source
(03:22):
here is looking at foundling law in Frontiers of Philosophy
and China from two thousand ten contends that their subtleties
involved that quote English language is unable to capture. So yeah,
we have to acknowledge linguistic possibilities. But on the other hand,
like thinking about like what is it as a modern human,
Like why do I like you have no problem imagining
(03:42):
a vacuum um or or even of a void, And
I think part of it maybe like just the mechanical
possibilities that we have now in the media evidence thereof. So,
for instance, when I think about a perfect vacuum, I
can I can imagine a device that mechanically makes it
so within say a closed space. I can think back
(04:03):
to footage of someone in a It's not a perfect vacuum,
but a place that has no air, that's sort of vacuum.
Because I guess we get into differences too. Are we
talking about a space without air um in which say
a scientist in a suit may drop a feather in
a bowling ball and do that whole experiment, or are
we talking about something that that is a true vacuum
(04:25):
with nothing in it at all, like a like an
absolute void um. And and there are differences there, but yeah,
as far as just like maybe it gets into the
idea of imagining a space with air in it. Like,
we we have this clear idea of what atmosphere is
and what air is, and we can also see and
(04:46):
behold and sort of to some degree understand the mechanics
by which that air may be removed from a space.
And therefore you could have a space where the visible
is not present and the invisible has been removed as well. Yeah,
that's a very good point. And I think for like
one major difference, maybe the UH unsettled question of like
(05:06):
whether the air itself has wait for much of human history,
Like if if you don't have that worked out, it
may just be harder to imagine what space devoid of
even gas particles would be. Yeah, but I want to
turn into some examples that Frank Close looks at in
this book, especially his his first chapter on sort of
the ancient history of the void in UH in physics,
(05:27):
to to look at how how this idea was thought
of before the modern era. So the pre Socratic Greek
philosopher Thals of Melitas, who lived from the seventh to
the sixth century b c. Writing about the idea of
emptiness or void without substance, is actually kind of tempted
to ask can there be such a thing as nothing?
(05:48):
If someone is able to think about it, wouldn't thinking
about it mean it was something? And again this raises
an interesting question for me. I mean, my initial reaction
is just like no, Like, you know, so imagine a
container with empty space in it. I don't think by
thinking about that we change the nature of what's in
the container. But this does kind of raise the specter
(06:10):
of like if there could be a vacuum for people
like Thiley's maybe this has almost more sort of totalizing
cosmic implications that the ability of a vacuum to exist
says something about the universe as a whole, not just
one region of the universe, say inside of a glass
bottle or something. So that's one level in which I respond.
(06:32):
But then on the other hand, I can sympathize with
thoughts like this knowing some things about modern physics, because
in a very real sense, empty space is I think
you can make the argument that it is not nothing.
Empty space is something even though it is not matter.
Uh So this may come from a failure to distinguish
(06:53):
between space and a concept like nothingness, in which case,
like if you're imagining space is something like space has properties,
then in fact it couldn't be nothing, which is what
Thai Las was thinking about. Yeah, this perhaps distinction between
nothingness and emptiness. Um, this whole thing about thinking about
(07:14):
it making it maybe less nothing. Um. This reminds me
of another paper I was looking at, Being in Nothingness
in Greek and Ancient Chinese philosophy by Ji Ming shin
philosophy East and West nine. Uh. This author points out
that in both Chinese Taoism and Greek philosophy you see
this culmination of things and nothingness. Quote, nothingness is the
(07:35):
nature of being in itself, which is absolutely transcendent and nameless.
So if I'm interpreting this correctly to sort of dual
identity of nothingness in these two different thoughts systems, nothingness
is ultimately that which comes before substance but also comes
before human attributed meaning. Um So yeah, like even thinking
of even giving it a name changes the nothingness of
(07:59):
it at least from these perspectives. Yes, though with Greek philosophy,
I know it very much depends on which philosopher you're
talking about, because a lot of these big Greek philosophers, Uh,
they were emphatic and specifically rejecting the idea that the
universe could have come from nothingness, that there could ever
have been nothingness, or that the universe would ever disappear
(08:21):
into nothingness like that was specifically uh, part of what
the cosmological history that the Ley's was arguing for. According
to Theiles, it would be impossible for the universe to
have come from nothingness. And it would be impossible for
it to ever become nothing. There's just sort of like
infinitely the same stuff. Without getting into the exacts of
it all though, when you hear some of these sweeping
(08:43):
explanations of what, say, the universe would be if it
were reduced to a singularity, you know, uh, that sort
of thing like, that's not nothing, it's something, but it's
such a strange and alien concept, so different from certainly
our perceivable reality, that it might as well be nothing.
You know. Yes, that's a good point. And of course,
(09:03):
again to highlight the difference between nothingness and empty space
and nothingness I think is much harder to define. I
don't know exactly what we mean when we talk about nothingness.
It's sort of a more uh slippery, mysterious concept, whereas
empty space. Again, it's not that we understand everything about it,
but it is something that has physical properties and can
(09:23):
be manipulated. We know some things about it, Yeah, like
even linguistically. When we talk about a vacuum, so we've
formed an artificial vacuum inside of a reinforced steel chamber,
does that steel chamber contain a vacuum and therefore the
vacuum is not nothing because it is a thing by
virtue of being different from everything surrounding it. Oh, because
(09:43):
it is contained. Yeah, well that raises another question of um.
When you ask whether a vacuum exists in nature, I
mean in reality, whenever we're talking about a vacuum, we're
talking about essentially low density gas. So and the question
is how low density does the gas have to get
before you are comfortable talking about a region of it
(10:06):
as a vacuum. So like and say that, and we
can come back to this maybe in in the next
part of the series or something. But like an interstellar voids,
there are still particles floating around out there. They're just
very far apart compared to much closer to stars or
in the atmosphere of a planet. But I guess the
question would be how far apart does every individual particle
(10:26):
of matter have to get before you say, okay, this
is really a total vacuum. Mhm. But to come back
to Thailey's for a second, Close makes an interesting argument
about Thailey's sort of having something in his cosmology similar
to uh to a kind of empty space, basically a
primeval material or a sort of ground state for the universe,
(10:50):
And Close argues that for Thailey's this ground state of
existence was water. This belief is related to the fact
that we can observe why are going through phase changes,
so we can see water as solid, ice, as liquid
as water, vapor and Close says that the LEAs assumed
that the diversity of forms went on from there, and
(11:11):
in fact water was the basis of every material on Earth. Rocks, plants, air, etcetera.
Are all somehow water in some some extrapolated form, and
so he writes quote, space for Thaile's is as empty
as it can be when all matter in it has
been turned into its primeval form, liquid water. Like the ocean.
(11:35):
Water thus contains every possible form of matter. I think
we've actually discussed this before. Yeah, in connection to his work,
like you get down to the idea of a cosmic ocean,
of a primordial ocean on which there is no land
and no being. So there are definitely similarities between imagining,
say the you know, the gods or the Creator or whatever,
(11:56):
hovering over a great void and hovering over a gray ocean.
That those are like similar ideas in some of these
ancient cosmologies at least, But anyway, going on from there,
in the fifth century b c. There's another pre Socratic
Greek philosopher, Empedicalles, who argued that there were actually four
fundamental forms of matter. Wasn't that everything came from water?
(12:18):
Like they least thought that there was in fact earth, air, fire,
and water, And empedically Is notably realized that air was
itself a substance and not merely empty space. He also
believed there was no such thing as empty space. But
of course the discovery that air is not empty space
does not mean that empty space cannot exist. But then
(12:40):
we we come to the atomists, who are very interesting
in their departure from these other ways of thinking. So uh.
The atomists included a number of ancient philosophers like Lucippus, Democritus,
and Epicurus, who believed, quite remarkably ahead of their time,
that all matter is actually made up of imperceptible like
tiny particles, which they called atoms from the Greek word
(13:04):
adam moss, which is derived from something that means like
cannot be cut or basically indivisible. Now, of course, today
we know that atoms are not actually indivisible. They're made
up of sub atomic particles like protons, neutrons, electrons, and
even protons and neutrons can be further subdivided. But ancient
atomists did not have the experimental apparatus needed to discover this. Instead,
(13:29):
they arrived at the atomic view of physics primarily by
way of thought, experiments, and everyday empirical observations, such as
the observation of things like the erosion of solid matter
in nature. So if you have a great, you know,
a grand marble staircase, and you notice that over the years,
the steps on the staircase are eroding. They're sort of
(13:50):
like sagging in the places where people walk on them. Well,
they're solid marble. Where are they going? How do marble
steps wear away over the ages? It must be because
each person who steps on them remove some tiny, invisibly
small amount of matter. But that invisibly small amount of matter,
those little atoms that are taken away accumulate over time
(14:12):
and the steps are worn down. But importantly for this discussion,
the atomists believed that there actually is such a thing
as empty space. In fact, it was core to their
theory that the universe was composed of atoms in motion.
Those atoms in motion needed a space through which to move.
And the atomists argued that if there were already something
(14:34):
in the place and atom was moving to, the atom
couldn't move there because then two atoms would be occupying
the same space at once. So there had to be
such a thing as empty space. That was the only
way that such space could come to be occupied. You know,
there has to be space for things to move into
where nothing can move. But after this we get back
(14:55):
to Aristotle because uh and we mentioned him at the
beginning of the first episode in this series. For better
or worse, Aristotle would pretty much have the last word
on this question for centuries to come, until experiments in
the seventeenth century would strongly challenge his decree. But Aristotle says,
there is no such thing as empty space. Uh. And
(15:15):
I was reading about the Aristotelian uh framework or foundation
for the science of the early modern period in the
Cambridge History of Science, volume three, edited by Lindberg at All.
This was in a chapter called Physics and Foundations by
the Princeton philosopher Daniel Garber. And uh. He makes some
(15:36):
interesting points, But reading this chapter, this is the way
I was thinking about it. So when we think of
physics today, we usually think of it as a science
contained within certain boundaries, like there are certain kinds of
questions that are physics questions, and there are other questions
that are not Physics. Is the study of properties of
matter and energy something like that, And that's a huge field,
(15:58):
so you can ask tons of stents in it, like
how are stars formed? Or what is the relationship between
particle mass and the Higgs field. But if in a
physics journal today you tried to submit a paper on
a question like what are the basic modes of existence?
And what is being? And what is the relationship of
those uh things to say, God, uh, this would probably
(16:23):
be rejected as outside the scope of the physical sciences,
you know, like the editors would say, you need to
submit this to a different journal. However, this attempted limitation
of scope was not always present in fields analogous to physics.
Throughout history. There are many times in history where these
things really kind of blend together, or at least, uh
(16:44):
philosophical foundations are thought to have relevant things to say
about physics theories. So uh, the these these philosophical foundations
might include religious world views, so you can think about
the way that um, the the scientists of the islam
world in the Middle Ages might have thought of Islam
as a theological foundation for the sciences, or the way
(17:06):
that Christian natural philosophers of Europe might have thought about
Christianity in the same way. But in the West there
was a major secular philosophical foundation of early science also,
and that was Aristotelianism, the philosophy of Aristotle, a fourth
century BC Greek philosopher. And I think it's fair to
(17:26):
say that for like hundreds of years, in the schools
and universities of of medieval through early modern Europe, the
philosophy of Aristotle was not taught in the way that
it would be taught in a college class today. Like
today you would teach it like here is an interesting
piece of intellectual history, maybe providing a certain point of
view and showing the development of how people thought about X,
(17:49):
Y or z. Instead, I think it was often taught
in a way that was closer to how people would
have thought about the Bible. It's like Aristotle said it.
That pretty much settles it. Yeah, So you end up
with with various discussions and arguments coming down to either
what Aristotle said or disagreements over what Aristotle did say
or meant or what he would have said or meant
(18:12):
about a given topic. Right so, and and to be clear,
it wasn't always this way. It wasn't that everybody thought
Aristotle was literally infallible. But it seems to me like
he was often treated by the scholastics as something approaching infallibility,
like it was just ludicrous to question Aristotle, though in
some cases people did. Thankank thank so, we should discuss
(18:42):
what Aristotle says about the void um. Aristotle denies the
possibility of the existence of empty space, specifically in his
book Physics Book for and, as is so often true
with these ancient philosophers, he makes his case for the
non existence of a vacuum not by like doing an
experiment and describing it, but by cold, rash eosination. He
(19:05):
is going to reason his way out of having to
believe in empty space. Garber, in his chapter quotes a
translation of Aristotle for one of his arguments along these lines.
Aristotle says, now it space or place has three dimensions length, breadth, depth,
the dimensions by which all body is bounded. But the
(19:26):
place cannot be body, for if it were, there would
be two bodies in the same place. What in the
world then are we to suppose place to be and
the implied answer is nothing. Uh, So not to kind
of interesting contradiction, It seems to me at least that
we had the atomists pointing to the fact that two
(19:47):
objects can't be in the same place at the same
time to prove that there must be empty space, because remember,
moving particles have to have unoccupied space to move into.
And here Aristotle is using the same ms in a
way to say that space cannot exist independent of matter,
or else it would have to occupy the same places
matter at the same time. But coming back to close,
(20:10):
he summarizes Aristotle's arguments by saying, quote, so for Aristotle,
logic seem to require that empty space cannot be something
and therefore is non existent. He defined the void as
where there is no body, and since the basic elements
of things exist eternally, there can be no place that
is completely empty. Aristotle may have been getting some mileage
(20:32):
here out of uh confusion over the difference between empty
space as something and like nothingness as as in a
way meaning non existence. Now. Garber, in his Physics and
Foundations chapter writes that by the thirteenth century, writers in
the Scholastic tradition in Europe who believed in Aristotelian dogmas
(20:53):
had begun assuming the existence of a natural force known
as horror vakay, again a phrase that Aristotle himself did
not use, but which aligned with his teaching on this matter,
that nature would not permit a vacuum, and the Scholastic
writers characterized this as a force in nature which prevents
vacuum of from emerging, almost like there's sort of a
(21:14):
law of nature something going on that will not let
a vacuum be created, and thus forces matter to fill
in the gaps. So you can pump out that container
as much as you want, but horror vakaye will prevent
it from actually being empty inside. Uh And and another
interesting thing I wanted to flag here is that Garber
(21:34):
notes a conflict between this Aristotelian dogma and some religious
reasoning that arose in the Church in the thirteenth century
that eventually led to the famous Condemnations of twelve seventy seven,
where we've got a bishop condemning Aristotle. Uh So, to
read from Garber here, quote, one consequence was that without
(21:56):
space outside of the finite world, not even God would
seem to be able to move the universe if he
chose to do so. This apparent consequence of Aristotelian doctrine
was rejected in the famous condemnation of Aristotle by Etienne Tempier,
the Bishop of Paris, in twelve seventy seven uh and
then quoting in translation, here we can dimn the proposition
(22:19):
that God could not move the heavens with rectilinear motion,
and the reason is that a vacuum would remain. So
Garber says, this really kind of put these scholastic Aristotelians
in a bind because in some ways they they had
to defend the possibility of some kind of empty space
existing in the universe, at least potentially for theological reasons,
(22:42):
but they didn't want to violate the principles of Aristotle
to which they were loyal. Mhm. But anyway, going on,
Frank Close makes an interesting argument that I think I
would agree with it. We shouldn't be too hard on
the prevailing Aristotelian belief in uh in orvakay because without
special equipment and experiments, I don't know, it really just
(23:05):
seems like that from everyday existence, like it seems like
reality prevents voids from forming. Examples given by the ancient
philosophers were things like, hey, you suck all the air
out of an empty wine skin, the wine skin collapses
like it shrinks in. Removing the air does not result
in a void inside the skin. It causes the walls
of the skin to shrink proportional to the amount of
(23:28):
air you're able to remove. You could also use this
belief in nature's hatred for the vacuum to explain the
workings of pumps and siphons. So beyond the fact that
Aristotle said it, it just kind of seemed right with
everyday experience. Yeah, I mean again, you're not walking around
your home and just suddenly walking into a vacuum, right Like,
(23:48):
even the empty rooms are are full, they're they're teeming
with with with matter. Uh. And these are I think
all great examples where you could you can imagine someone saying,
look proof right here, look at this wine skin. If
you can form a void in this wide skin, then
I'll believe you. Otherwise, absolutely not. So while horror Vakay
(24:08):
had its critics for a long time, I think it's
safe to say that it was really like the seventeenth
century where this idea was laid to rest. So coming
back to this idea of like when you suck on
a straw, what is the force that actually causes the
liquid in your drink to rise up the straw into
your mouth. You could imagine it as a vacuum created
(24:30):
that like sort of resists formation and thus sucks the
liquid up. The same question was actually raised around the
year sixteen hundred UH and brought to the attention of Galileo.
There are some examples I've read about this. One is
an example of UH. I think a scientist sort of
at the time a natural philosopher who had been trying
(24:50):
to construct a big siphon and encountered problems at at
a certain height of the siphon. But then I've also
read about an influence here being people digging wells and
mine shafts who would try to remove water from these
pits using like plunger based pumps to lift the water
out through a pipe. There was a problem in all
(25:11):
these cases with the siphons and the pumps. Basically, the
pumps stopped working after a certain height, after the water
was raised roughly ten point three meters or so, when
you had ten point three ms worth of a column
in the pipe, it would stop going higher, wouldn't climb
the pipe anymore, and instead a gap would appear between
(25:32):
the water column and the plunger or the piston or
whatever you're using to pump it out. So what's going
on here? What was the what was actually limiting the
height of the water pump system. Well, Galileo investigated this question,
and he suspected that the force that drew water up
through a pump or a siphon may in fact be
(25:52):
the force of horror Vakawi. So the vacuum is resisting
formation and thus holding water up after itself. So when
you try to run the pump, the fact that the
universe is resisting creating a vacuum in that space in
between is forcing water up. I love how this Uh
this this also kind of implies that Galileo was maybe
(26:16):
not solving a physics problem, but responding to a pump problem.
Get Galileo on the horn. We got a problem with
this pump here se if he see it has time
this afternoon to look at it. Well, I mean that's
the wonderful thing about Galileo. I mean, he he was
at all ends of the spectrum here right working on
theoretical problems and astronomy and every day you know, mechanical
physics problems. But all, yeah, it is hilarious. Imagine. I
(26:39):
don't know exactly when this was first raised to him,
but it's it's fun to imagine somebody was like trying
to get water out of their basement or their mind shaft,
and that they were just able to call up Galileo,
or maybe he arrives at his end. He's like a superhero. Yeah. Anyway, Yeah,
so he imagines that that maybe it is the force
of natures existing the formation of a vacuum that pulls
(27:03):
the water up the pipe. But then at a certain point,
the weight of the water in the pipe is too much.
There's too much water, and it's the vacuum resistance can't
carry it any higher. It has reached the limit of
the strength of nature's resistance to a vacuum. So fascinating question,
but Galileo never solved it in his lifetime. Thank you,
(27:29):
Thank you, thank you. Into a couple of other figures,
we got a guy named Gasparo Bertie who lived sixteen
hundred sixteen forty three, and Evangelista Toricelli sixteen o eight
to sixty seven and Robbi I got a picture of
tor Chelli for you to look at here. I think
he is incredibly notable for having a Batman symbol as
(27:51):
a mustache. Yeah, certain portraits of this guy, um have
it worse than others, but yes, it has this. I
guess it's sort of a Vandi though in other portraits
it really feels uh cruciform. It feels like it looks
I mean, it looks like he took a crucifix with
flared arms and was perhaps kissing it so much that
(28:13):
the barber had to uh shave him around that crucifix,
resulting in this hairstyle. Um, it's um, it's a lot.
I want my muzzle to make you think of the passion.
It seems if it is a bold look. So these
two Italian scientists, a Bertie and Torcelli performed similar experiments
in the early sixteen forties that would clarify what was
(28:36):
going on here. Bertie did an experiment with water, and
then several years later Torcelli did a more definitive and
more famous experiment with quicksilver, which we know today as
elemental liquid mercury. So Torchelli's experiment went like this. You
would get a glass tube about one meter long and
(28:57):
fill it completely with liquid mercury. So this tube would
be closed completely at one end and open at the other.
So you fill it with liquid mercury, and you temporarily
plug up the open end so one end is permanently
closed one end, you know, put a finger over it
to close it, and then you flip the tube upright
(29:17):
vertical and sit the open end down in a big
basin of more liquid mercury. So you've got like a
tub of liquid mercury. So you flip it up. You
have the the plugged open end facing down into the
lake of mercury, and then you unplug it. You remove
the finger or the plug. Now remember the tube started
(29:38):
totally full of mercury, but now that it's unplugged, the
mercury can flow down into the basin with the rest
of the mercury. And when he tried this, the mercury
and the tube did fall, but not all the way.
It fell to leave a column of mercury about seventy
six cimeters in height, and then a gap for the
(29:58):
rest of the tube length up at the closed top.
So what was the gap, Well, Torcelli reasoned that it
was actually a vacuum. There was effectively nothing inside the
tube for those empty centimeters above the column of mercury.
The other guy, Gasparo Gasparo Bertie, had performed a similar
(30:18):
experiment with water several years before, and they both Both
of these experiments seemed to provide evidence that it was
indeed possible for empty space to exist. But the question remained,
what was holding up the water in the tube and
why would the water only rise up the tube to
a certain height, or, to put it in another way,
(30:41):
why would the liquid only fall down to a certain
consistent height uh in the tube. The answer was also
illuminated by Torchli's experiment, for one thing, by comparing the
difference between the height of a water column a tube
and the height of a mercury column in a tube.
They were different because water and mercury have different densities.
(31:03):
And so what Torcelli proposed, and what in fact was correct,
is that the force that kept the water or the
mercury column raised in the tube was actually the force
of atmospheric pressure, the pressure of the air pushing down
on the water or the mercury in the basin. Below,
(31:24):
and these tube systems assembled by Birdie and Torcelli were
actually systems for establishing an equal librium between the weight
of the liquid in this column in the tube and
the weight the atmosphere exerts on the liquid in the
basin below. The liquid and the sealed tube would fall
until the weight of the column was equal to the
(31:45):
atmospheric pressure, and then it would float and fall no more,
leaving mostly a vacuum in the space above. However, there
was another question. There was the question of what is
causing this. It was important to demonstrate that the vacuum
hume was not the thing exerting the force. Tori Shelley
did this with another experiment involving two mercury tubes, one
(32:08):
with a sort of bull on the sealed top end,
and the bulb would mean that a greater volume of
empty space was left at the top when the liquid
fell after the bottom was unplugged. So would that make
the mercury fall to a different level, And it turns
out the extra empty space did not matter at all.
The liquid fell to the same height regardless, So the
(32:32):
force exerted on the column of water in the pipe
or the tube was not a pull from the vacuum.
It was not a pull proportional to the amount of
vacuum created. It was a push proportional to the relationship
between the atmospheric pressure and the density of the liquid.
And this was further demonstrated in experiments performed by Blaze,
(32:52):
Pascal and uh and I think with some input from Descartes,
but Blaze, Pascal and collaborators testing a sim millarier experiment
at different altitude, so you might you test it at
the foot of a mountain and then go up to
the top of a mountain and test again and see
if there are differences. And indeed they found that higher
up on a mountain, the column of mercury would be
(33:13):
lower because the atmospheric pressure was lower. And in fact,
these experiments in the apparatus used the apparatus what's the
plural of that apparati or apparatus is anyway, they this
stuff went on to become the basis of the invention
known as the barometer, which is used to detect atmospheric pressure,
and for much of history, one of the most common
(33:36):
liquids used in it has been quicksilver or mercury. So
people here in the seventeenth century had learned a number
of things. Air has weight, the atmosphere does have weight,
and it presses down and this affects all different kinds
of fluid dynamics, enclosed containers, and at least in an
approximate sense, vacuums can be created. But the scientific story
(33:59):
does not stop there, and maybe in the next episode
we can get into a little more detail on that history,
because there's plenty more. But also we've got to talk
about psychology and horror. Vakawy because I don't know about you,
but you ever have that creepy feeling when you're reminded
of like walking around at school when there was nobody there,
(34:19):
or any other place when you were a kid that
normally had people in it, but then there were no
people in it and you were there and it just
didn't feel right. I think about that all the time. Yeah,
And of course this this plays into a lot of
our our horror movies as well, and a lot of
our fantastic horror scenarios. So we'll discuss some of those.
But but you know this, coming back to this, this
realization that the air has weight, that atmospheric pressure is
(34:43):
involved in these observations. Um, it's it's something that I feel.
Even as modern humans. We have to remind ourselves with
this time and time again, because we can also fall
into that line of thinking where we think of an
empty room is empty. We think of a clear sky
as being empty. Uh. But of course none of those
things are empty. All of those things are completely filled
up with air exerting a pressure on us, but a
(35:06):
pressure that is so ambient that we do not register
it as being pressure. Absolutely, And the way that this
pressure affects other things, say like chemical properties. I think
about the boiling point of water and how that's affected
by atmospheric pressure at different altitudes, and how that affects
something is mundane as cooking, How like cooking has to
be different at different altitudes. Yeah. Ultimately we have to
(35:29):
realize that we are creatures that evolved to reside within
an atmospheric body. And uh, and and even then only
certain parts of that atmospheric body. And then if we
want to bring fire with us and use it to
boil matter to eat, we have to take into account
that it's going to boil differently depending on how far
(35:50):
up into that massive body of air we travel. We
discussed this in a couple of episodes a long time ago.
I think maybe they were the ones about sacred experiences
on mountaintops people have had. But the fact about how
basically like you can't boil potatoes on top of Mount Everest.
People have tried. You try to boil food to cook it.
(36:10):
The problem is the boiling point of water after a
certain altitude gets too low, and so your water is
boiling in the pot, but it's not hot enough to
cook your food, Like boiling water is no longer sufficiently hot. Wow,
And of course it's boiling. Can't get any hotter than boiling,
so you're just stuck like it won't cook. It's hard
to come up with a response to that. I've forgotten
(36:31):
about that tidbit regarding cooking potatoes on Mount Everest for
some reason. That's that's um, that's that's That's almost more
mind blowing than anything we've we've discussed in this episode,
I guess, because it comes down to what we were
talking about earlier, like the perceived world, the world we
can relate to, versus the the world that seems to
(36:52):
exist only within the the lofty conversations of philosophers and
scientists like the experience of boiling potatoes but not being
able to cook them through that boiling like that feels
like the Twilight Zone. That feels like something that shouldn't be.
Rod Serling is kind of a talking to you about this. Yeah, alright, Well,
(37:12):
we're gonna go and close this episode out, but we'll
be back with more discussions of the vacuum, the void,
and so forth in the meantime. Right into us. We'd
love to hear from everyone out there. Uh, what are
your thoughts about some of the ideas we presented in
this episode, and hey, we would we would love to
hear your cooking anecdotes from from different altitudes if you
(37:35):
have some of those right in. Uh, we'd love to
hear about your your mishaps with boiling potatoes and mountaintops.
I know we have some mountaineers out there, Yes we do. Yeah.
Reminder that Stuff to Blow Your Mind is primarily a
science podcast with core episodes on Tuesdays and Thursdays. On
Monday's we do a listener mail episode, on Wednesday's we
do a short form artifact or monster fact episode, and
(37:55):
on Friday's we do Weird How Cinema. That's our time
to set aside most serious concerns and just talk about
a strange film. Huge thanks to our audio producer J J. Pauseway.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at stuff to Blow
your Mind dot com. Stuff to Blow Your Mind is
(38:24):
production of I Heart Radio. For more podcasts for my
heart Radio, visit the iHeart Radio app, Apple Podcasts, or
wherever you listening to your favorite shows.
Welcome to Stuff to Blow Your Mind production of My
Heart Radio. Hey you welcome to Stuff to Blow your Mind.
My name is Robert Lamb and I'm Joe McCormick, and
we're back with part three of our series on Horror
VAKUI or Fear of the Void, which we have We've
(00:25):
been mainly focusing I think on like art and design
in the past couple of episodes, but today I wanted
to take a look at the history of the vacuum
and specifically resistance to the idea of the vacuum in
philosophy and physics. And to begin, I was reading about
the scientific history of vacuum physics in a book called
(00:48):
The Void by Frank Close from Oxford University Press in
two thousand seven. Frank Close is a professor of physics
at at Oxford I think emeritus now, But anyway, I
was reading about this and he included a quote from
the rig Veda that I thought was very interesting. This
is from the creation Hymn of the rig Veda, which says,
(01:09):
in translation, there was neither non existence nor existence. Then
there was neither the realm of space nor the sky,
which is beyond what stirred where and I really like
this because it I think it encapsulates a kind of,
uh a fascinated but challenging history of attempts to conceptualize
(01:34):
empty space, to even imagine what empty space would mean
if it were to exist. Because I noticed kind of
a gap here. As far as I can tell, most
people all around the world today, even in various you know,
different cultures, whatever, really, as as far as I can tell,
don't seem to express any major problems making sense of
(01:56):
the idea of empty space. Obviously, there's a lot we
don't know about the nature of space. What is space,
where does it come from, what different kinds of space
could there be, and so forth. So space is still
a vessel of many mysteries. It's not like we've got
it all solved. But if you just simplify the idea
to the basics, I and I think most people don't
(02:18):
have any problem imagining the concept of an area of
three dimensional space with no particles in it. That just yeah, okay,
that that makes sense as an idea to me. But
if you read about how ancient Greek philosophers wrote about
this question, I do not get the impression that the
same was generally true for them, not only did many
(02:40):
of them deny the possibility of empty space existing. Sometimes
I get the feeling that they are struggling to even
imagine what the concept would mean. Do Do you know
what I'm getting out here? Rob, Yeah? Yeah, this, Um,
this is something we talked a little bit about off
my before the the episode here. Um it's it's it's
(03:00):
it's kind of complicated. I mean at one level, yeah,
they're They're always going to be linguistic possibilities in play.
For example, I was looking into some sources on the
void in Chinese philosophy and you run into, for example,
that they're separate terms for such concepts as emptiness, nothingness,
and the infinite or the absolute and and one source
(03:22):
here is looking at foundling law in Frontiers of Philosophy
and China from two thousand ten contends that their subtleties
involved that quote English language is unable to capture. So yeah,
we have to acknowledge linguistic possibilities. But on the other hand,
like thinking about like what is it as a modern human,
Like why do I like you have no problem imagining
(03:42):
a vacuum um or or even of a void, And
I think part of it maybe like just the mechanical
possibilities that we have now in the media evidence thereof. So,
for instance, when I think about a perfect vacuum, I
can I can imagine a device that mechanically makes it
so within say a closed space. I can think back
(04:03):
to footage of someone in a It's not a perfect vacuum,
but a place that has no air, that's sort of vacuum.
Because I guess we get into differences too. Are we
talking about a space without air um in which say
a scientist in a suit may drop a feather in
a bowling ball and do that whole experiment, or are
we talking about something that that is a true vacuum
(04:25):
with nothing in it at all, like a like an
absolute void um. And and there are differences there, but yeah,
as far as just like maybe it gets into the
idea of imagining a space with air in it. Like,
we we have this clear idea of what atmosphere is
and what air is, and we can also see and
(04:46):
behold and sort of to some degree understand the mechanics
by which that air may be removed from a space.
And therefore you could have a space where the visible
is not present and the invisible has been removed as well. Yeah,
that's a very good point. And I think for like
one major difference, maybe the UH unsettled question of like
(05:06):
whether the air itself has wait for much of human history,
Like if if you don't have that worked out, it
may just be harder to imagine what space devoid of
even gas particles would be. Yeah, but I want to
turn into some examples that Frank Close looks at in
this book, especially his his first chapter on sort of
the ancient history of the void in UH in physics,
(05:27):
to to look at how how this idea was thought
of before the modern era. So the pre Socratic Greek
philosopher Thals of Melitas, who lived from the seventh to
the sixth century b c. Writing about the idea of
emptiness or void without substance, is actually kind of tempted
to ask can there be such a thing as nothing?
(05:48):
If someone is able to think about it, wouldn't thinking
about it mean it was something? And again this raises
an interesting question for me. I mean, my initial reaction
is just like no, Like, you know, so imagine a
container with empty space in it. I don't think by
thinking about that we change the nature of what's in
the container. But this does kind of raise the specter
(06:10):
of like if there could be a vacuum for people
like Thiley's maybe this has almost more sort of totalizing
cosmic implications that the ability of a vacuum to exist
says something about the universe as a whole, not just
one region of the universe, say inside of a glass
bottle or something. So that's one level in which I respond.
(06:32):
But then on the other hand, I can sympathize with
thoughts like this knowing some things about modern physics, because
in a very real sense, empty space is I think
you can make the argument that it is not nothing.
Empty space is something even though it is not matter.
Uh So this may come from a failure to distinguish
(06:53):
between space and a concept like nothingness, in which case,
like if you're imagining space is something like space has properties,
then in fact it couldn't be nothing, which is what
Thai Las was thinking about. Yeah, this perhaps distinction between
nothingness and emptiness. Um, this whole thing about thinking about
(07:14):
it making it maybe less nothing. Um. This reminds me
of another paper I was looking at, Being in Nothingness
in Greek and Ancient Chinese philosophy by Ji Ming shin
philosophy East and West nine. Uh. This author points out
that in both Chinese Taoism and Greek philosophy you see
this culmination of things and nothingness. Quote, nothingness is the
(07:35):
nature of being in itself, which is absolutely transcendent and nameless.
So if I'm interpreting this correctly to sort of dual
identity of nothingness in these two different thoughts systems, nothingness
is ultimately that which comes before substance but also comes
before human attributed meaning. Um So yeah, like even thinking
of even giving it a name changes the nothingness of
(07:59):
it at least from these perspectives. Yes, though with Greek philosophy,
I know it very much depends on which philosopher you're
talking about, because a lot of these big Greek philosophers, Uh,
they were emphatic and specifically rejecting the idea that the
universe could have come from nothingness, that there could ever
have been nothingness, or that the universe would ever disappear
(08:21):
into nothingness like that was specifically uh, part of what
the cosmological history that the Ley's was arguing for. According
to Theiles, it would be impossible for the universe to
have come from nothingness. And it would be impossible for
it to ever become nothing. There's just sort of like
infinitely the same stuff. Without getting into the exacts of
it all though, when you hear some of these sweeping
(08:43):
explanations of what, say, the universe would be if it
were reduced to a singularity, you know, uh, that sort
of thing like, that's not nothing, it's something, but it's
such a strange and alien concept, so different from certainly
our perceivable reality, that it might as well be nothing.
You know. Yes, that's a good point. And of course,
(09:03):
again to highlight the difference between nothingness and empty space
and nothingness I think is much harder to define. I
don't know exactly what we mean when we talk about nothingness.
It's sort of a more uh slippery, mysterious concept, whereas
empty space. Again, it's not that we understand everything about it,
but it is something that has physical properties and can
(09:23):
be manipulated. We know some things about it, Yeah, like
even linguistically. When we talk about a vacuum, so we've
formed an artificial vacuum inside of a reinforced steel chamber,
does that steel chamber contain a vacuum and therefore the
vacuum is not nothing because it is a thing by
virtue of being different from everything surrounding it. Oh, because
(09:43):
it is contained. Yeah, well that raises another question of um.
When you ask whether a vacuum exists in nature, I
mean in reality, whenever we're talking about a vacuum, we're
talking about essentially low density gas. So and the question
is how low density does the gas have to get
before you are comfortable talking about a region of it
(10:06):
as a vacuum. So like and say that, and we
can come back to this maybe in in the next
part of the series or something. But like an interstellar voids,
there are still particles floating around out there. They're just
very far apart compared to much closer to stars or
in the atmosphere of a planet. But I guess the
question would be how far apart does every individual particle
(10:26):
of matter have to get before you say, okay, this
is really a total vacuum. Mhm. But to come back
to Thailey's for a second, Close makes an interesting argument
about Thailey's sort of having something in his cosmology similar
to uh to a kind of empty space, basically a
primeval material or a sort of ground state for the universe,
(10:50):
And Close argues that for Thailey's this ground state of
existence was water. This belief is related to the fact
that we can observe why are going through phase changes,
so we can see water as solid, ice, as liquid
as water, vapor and Close says that the LEAs assumed
that the diversity of forms went on from there, and
(11:11):
in fact water was the basis of every material on Earth. Rocks, plants, air, etcetera.
Are all somehow water in some some extrapolated form, and
so he writes quote, space for Thaile's is as empty
as it can be when all matter in it has
been turned into its primeval form, liquid water. Like the ocean.
(11:35):
Water thus contains every possible form of matter. I think
we've actually discussed this before. Yeah, in connection to his work,
like you get down to the idea of a cosmic ocean,
of a primordial ocean on which there is no land
and no being. So there are definitely similarities between imagining,
say the you know, the gods or the Creator or whatever,
(11:56):
hovering over a great void and hovering over a gray ocean.
That those are like similar ideas in some of these
ancient cosmologies at least, But anyway, going on from there,
in the fifth century b c. There's another pre Socratic
Greek philosopher, Empedicalles, who argued that there were actually four
fundamental forms of matter. Wasn't that everything came from water?
(12:18):
Like they least thought that there was in fact earth, air, fire,
and water, And empedically Is notably realized that air was
itself a substance and not merely empty space. He also
believed there was no such thing as empty space. But
of course the discovery that air is not empty space
does not mean that empty space cannot exist. But then
(12:40):
we we come to the atomists, who are very interesting
in their departure from these other ways of thinking. So uh.
The atomists included a number of ancient philosophers like Lucippus, Democritus,
and Epicurus, who believed, quite remarkably ahead of their time,
that all matter is actually made up of imperceptible like
tiny particles, which they called atoms from the Greek word
(13:04):
adam moss, which is derived from something that means like
cannot be cut or basically indivisible. Now, of course, today
we know that atoms are not actually indivisible. They're made
up of sub atomic particles like protons, neutrons, electrons, and
even protons and neutrons can be further subdivided. But ancient
atomists did not have the experimental apparatus needed to discover this. Instead,
(13:29):
they arrived at the atomic view of physics primarily by
way of thought, experiments, and everyday empirical observations, such as
the observation of things like the erosion of solid matter
in nature. So if you have a great, you know,
a grand marble staircase, and you notice that over the years,
the steps on the staircase are eroding. They're sort of
(13:50):
like sagging in the places where people walk on them. Well,
they're solid marble. Where are they going? How do marble
steps wear away over the ages? It must be because
each person who steps on them remove some tiny, invisibly
small amount of matter. But that invisibly small amount of matter,
those little atoms that are taken away accumulate over time
(14:12):
and the steps are worn down. But importantly for this discussion,
the atomists believed that there actually is such a thing
as empty space. In fact, it was core to their
theory that the universe was composed of atoms in motion.
Those atoms in motion needed a space through which to move.
And the atomists argued that if there were already something
(14:34):
in the place and atom was moving to, the atom
couldn't move there because then two atoms would be occupying
the same space at once. So there had to be
such a thing as empty space. That was the only
way that such space could come to be occupied. You know,
there has to be space for things to move into
where nothing can move. But after this we get back
(14:55):
to Aristotle because uh and we mentioned him at the
beginning of the first episode in this series. For better
or worse, Aristotle would pretty much have the last word
on this question for centuries to come, until experiments in
the seventeenth century would strongly challenge his decree. But Aristotle says,
there is no such thing as empty space. Uh. And
(15:15):
I was reading about the Aristotelian uh framework or foundation
for the science of the early modern period in the
Cambridge History of Science, volume three, edited by Lindberg at All.
This was in a chapter called Physics and Foundations by
the Princeton philosopher Daniel Garber. And uh. He makes some
(15:36):
interesting points, But reading this chapter, this is the way
I was thinking about it. So when we think of
physics today, we usually think of it as a science
contained within certain boundaries, like there are certain kinds of
questions that are physics questions, and there are other questions
that are not Physics. Is the study of properties of
matter and energy something like that, And that's a huge field,
(15:58):
so you can ask tons of stents in it, like
how are stars formed? Or what is the relationship between
particle mass and the Higgs field. But if in a
physics journal today you tried to submit a paper on
a question like what are the basic modes of existence?
And what is being? And what is the relationship of
those uh things to say, God, uh, this would probably
(16:23):
be rejected as outside the scope of the physical sciences,
you know, like the editors would say, you need to
submit this to a different journal. However, this attempted limitation
of scope was not always present in fields analogous to physics.
Throughout history. There are many times in history where these
things really kind of blend together, or at least, uh
(16:44):
philosophical foundations are thought to have relevant things to say
about physics theories. So uh, the these these philosophical foundations
might include religious world views, so you can think about
the way that um, the the scientists of the islam
world in the Middle Ages might have thought of Islam
as a theological foundation for the sciences, or the way
(17:06):
that Christian natural philosophers of Europe might have thought about
Christianity in the same way. But in the West there
was a major secular philosophical foundation of early science also,
and that was Aristotelianism, the philosophy of Aristotle, a fourth
century BC Greek philosopher. And I think it's fair to
(17:26):
say that for like hundreds of years, in the schools
and universities of of medieval through early modern Europe, the
philosophy of Aristotle was not taught in the way that
it would be taught in a college class today. Like
today you would teach it like here is an interesting
piece of intellectual history, maybe providing a certain point of
view and showing the development of how people thought about X,
(17:49):
Y or z. Instead, I think it was often taught
in a way that was closer to how people would
have thought about the Bible. It's like Aristotle said it.
That pretty much settles it. Yeah, So you end up
with with various discussions and arguments coming down to either
what Aristotle said or disagreements over what Aristotle did say
or meant or what he would have said or meant
(18:12):
about a given topic. Right so, and and to be clear,
it wasn't always this way. It wasn't that everybody thought
Aristotle was literally infallible. But it seems to me like
he was often treated by the scholastics as something approaching infallibility,
like it was just ludicrous to question Aristotle, though in
some cases people did. Thankank thank so, we should discuss
(18:42):
what Aristotle says about the void um. Aristotle denies the
possibility of the existence of empty space, specifically in his
book Physics Book for and, as is so often true
with these ancient philosophers, he makes his case for the
non existence of a vacuum not by like doing an
experiment and describing it, but by cold, rash eosination. He
(19:05):
is going to reason his way out of having to
believe in empty space. Garber, in his chapter quotes a
translation of Aristotle for one of his arguments along these lines.
Aristotle says, now it space or place has three dimensions length, breadth, depth,
the dimensions by which all body is bounded. But the
(19:26):
place cannot be body, for if it were, there would
be two bodies in the same place. What in the
world then are we to suppose place to be and
the implied answer is nothing. Uh, So not to kind
of interesting contradiction, It seems to me at least that
we had the atomists pointing to the fact that two
(19:47):
objects can't be in the same place at the same
time to prove that there must be empty space, because remember,
moving particles have to have unoccupied space to move into.
And here Aristotle is using the same ms in a
way to say that space cannot exist independent of matter,
or else it would have to occupy the same places
matter at the same time. But coming back to close,
(20:10):
he summarizes Aristotle's arguments by saying, quote, so for Aristotle,
logic seem to require that empty space cannot be something
and therefore is non existent. He defined the void as
where there is no body, and since the basic elements
of things exist eternally, there can be no place that
is completely empty. Aristotle may have been getting some mileage
(20:32):
here out of uh confusion over the difference between empty
space as something and like nothingness as as in a
way meaning non existence. Now. Garber, in his Physics and
Foundations chapter writes that by the thirteenth century, writers in
the Scholastic tradition in Europe who believed in Aristotelian dogmas
(20:53):
had begun assuming the existence of a natural force known
as horror vakay, again a phrase that Aristotle himself did
not use, but which aligned with his teaching on this matter,
that nature would not permit a vacuum, and the Scholastic
writers characterized this as a force in nature which prevents
vacuum of from emerging, almost like there's sort of a
(21:14):
law of nature something going on that will not let
a vacuum be created, and thus forces matter to fill
in the gaps. So you can pump out that container
as much as you want, but horror vakaye will prevent
it from actually being empty inside. Uh And and another
interesting thing I wanted to flag here is that Garber
(21:34):
notes a conflict between this Aristotelian dogma and some religious
reasoning that arose in the Church in the thirteenth century
that eventually led to the famous Condemnations of twelve seventy seven,
where we've got a bishop condemning Aristotle. Uh So, to
read from Garber here, quote, one consequence was that without
(21:56):
space outside of the finite world, not even God would
seem to be able to move the universe if he
chose to do so. This apparent consequence of Aristotelian doctrine
was rejected in the famous condemnation of Aristotle by Etienne Tempier,
the Bishop of Paris, in twelve seventy seven uh and
then quoting in translation, here we can dimn the proposition
(22:19):
that God could not move the heavens with rectilinear motion,
and the reason is that a vacuum would remain. So
Garber says, this really kind of put these scholastic Aristotelians
in a bind because in some ways they they had
to defend the possibility of some kind of empty space
existing in the universe, at least potentially for theological reasons,
(22:42):
but they didn't want to violate the principles of Aristotle
to which they were loyal. Mhm. But anyway, going on,
Frank Close makes an interesting argument that I think I
would agree with it. We shouldn't be too hard on
the prevailing Aristotelian belief in uh in orvakay because without
special equipment and experiments, I don't know, it really just
(23:05):
seems like that from everyday existence, like it seems like
reality prevents voids from forming. Examples given by the ancient
philosophers were things like, hey, you suck all the air
out of an empty wine skin, the wine skin collapses
like it shrinks in. Removing the air does not result
in a void inside the skin. It causes the walls
of the skin to shrink proportional to the amount of
(23:28):
air you're able to remove. You could also use this
belief in nature's hatred for the vacuum to explain the
workings of pumps and siphons. So beyond the fact that
Aristotle said it, it just kind of seemed right with
everyday experience. Yeah, I mean again, you're not walking around
your home and just suddenly walking into a vacuum, right Like,
(23:48):
even the empty rooms are are full, they're they're teeming
with with with matter. Uh. And these are I think
all great examples where you could you can imagine someone saying,
look proof right here, look at this wine skin. If
you can form a void in this wide skin, then
I'll believe you. Otherwise, absolutely not. So while horror Vakay
(24:08):
had its critics for a long time, I think it's
safe to say that it was really like the seventeenth
century where this idea was laid to rest. So coming
back to this idea of like when you suck on
a straw, what is the force that actually causes the
liquid in your drink to rise up the straw into
your mouth. You could imagine it as a vacuum created
(24:30):
that like sort of resists formation and thus sucks the
liquid up. The same question was actually raised around the
year sixteen hundred UH and brought to the attention of Galileo.
There are some examples I've read about this. One is
an example of UH. I think a scientist sort of
at the time a natural philosopher who had been trying
(24:50):
to construct a big siphon and encountered problems at at
a certain height of the siphon. But then I've also
read about an influence here being people digging wells and
mine shafts who would try to remove water from these
pits using like plunger based pumps to lift the water
out through a pipe. There was a problem in all
(25:11):
these cases with the siphons and the pumps. Basically, the
pumps stopped working after a certain height, after the water
was raised roughly ten point three meters or so, when
you had ten point three ms worth of a column
in the pipe, it would stop going higher, wouldn't climb
the pipe anymore, and instead a gap would appear between
(25:32):
the water column and the plunger or the piston or
whatever you're using to pump it out. So what's going
on here? What was the what was actually limiting the
height of the water pump system. Well, Galileo investigated this question,
and he suspected that the force that drew water up
through a pump or a siphon may in fact be
(25:52):
the force of horror Vakawi. So the vacuum is resisting
formation and thus holding water up after itself. So when
you try to run the pump, the fact that the
universe is resisting creating a vacuum in that space in
between is forcing water up. I love how this Uh
this this also kind of implies that Galileo was maybe
(26:16):
not solving a physics problem, but responding to a pump problem.
Get Galileo on the horn. We got a problem with
this pump here se if he see it has time
this afternoon to look at it. Well, I mean that's
the wonderful thing about Galileo. I mean, he he was
at all ends of the spectrum here right working on
theoretical problems and astronomy and every day you know, mechanical
physics problems. But all, yeah, it is hilarious. Imagine. I
(26:39):
don't know exactly when this was first raised to him,
but it's it's fun to imagine somebody was like trying
to get water out of their basement or their mind shaft,
and that they were just able to call up Galileo,
or maybe he arrives at his end. He's like a superhero. Yeah. Anyway, Yeah,
so he imagines that that maybe it is the force
of natures existing the formation of a vacuum that pulls
(27:03):
the water up the pipe. But then at a certain point,
the weight of the water in the pipe is too much.
There's too much water, and it's the vacuum resistance can't
carry it any higher. It has reached the limit of
the strength of nature's resistance to a vacuum. So fascinating question,
but Galileo never solved it in his lifetime. Thank you,
(27:29):
Thank you, thank you. Into a couple of other figures,
we got a guy named Gasparo Bertie who lived sixteen
hundred sixteen forty three, and Evangelista Toricelli sixteen o eight
to sixty seven and Robbi I got a picture of
tor Chelli for you to look at here. I think
he is incredibly notable for having a Batman symbol as
(27:51):
a mustache. Yeah, certain portraits of this guy, um have
it worse than others, but yes, it has this. I
guess it's sort of a Vandi though in other portraits
it really feels uh cruciform. It feels like it looks
I mean, it looks like he took a crucifix with
flared arms and was perhaps kissing it so much that
(28:13):
the barber had to uh shave him around that crucifix,
resulting in this hairstyle. Um, it's um, it's a lot.
I want my muzzle to make you think of the passion.
It seems if it is a bold look. So these
two Italian scientists, a Bertie and Torcelli performed similar experiments
in the early sixteen forties that would clarify what was
(28:36):
going on here. Bertie did an experiment with water, and
then several years later Torcelli did a more definitive and
more famous experiment with quicksilver, which we know today as
elemental liquid mercury. So Torchelli's experiment went like this. You
would get a glass tube about one meter long and
(28:57):
fill it completely with liquid mercury. So this tube would
be closed completely at one end and open at the other.
So you fill it with liquid mercury, and you temporarily
plug up the open end so one end is permanently
closed one end, you know, put a finger over it
to close it, and then you flip the tube upright
(29:17):
vertical and sit the open end down in a big
basin of more liquid mercury. So you've got like a
tub of liquid mercury. So you flip it up. You
have the the plugged open end facing down into the
lake of mercury, and then you unplug it. You remove
the finger or the plug. Now remember the tube started
(29:38):
totally full of mercury, but now that it's unplugged, the
mercury can flow down into the basin with the rest
of the mercury. And when he tried this, the mercury
and the tube did fall, but not all the way.
It fell to leave a column of mercury about seventy
six cimeters in height, and then a gap for the
(29:58):
rest of the tube length up at the closed top.
So what was the gap, Well, Torcelli reasoned that it
was actually a vacuum. There was effectively nothing inside the
tube for those empty centimeters above the column of mercury.
The other guy, Gasparo Gasparo Bertie, had performed a similar
(30:18):
experiment with water several years before, and they both Both
of these experiments seemed to provide evidence that it was
indeed possible for empty space to exist. But the question remained,
what was holding up the water in the tube and
why would the water only rise up the tube to
a certain height, or, to put it in another way,
(30:41):
why would the liquid only fall down to a certain
consistent height uh in the tube. The answer was also
illuminated by Torchli's experiment, for one thing, by comparing the
difference between the height of a water column a tube
and the height of a mercury column in a tube.
They were different because water and mercury have different densities.
(31:03):
And so what Torcelli proposed, and what in fact was correct,
is that the force that kept the water or the
mercury column raised in the tube was actually the force
of atmospheric pressure, the pressure of the air pushing down
on the water or the mercury in the basin. Below,
(31:24):
and these tube systems assembled by Birdie and Torcelli were
actually systems for establishing an equal librium between the weight
of the liquid in this column in the tube and
the weight the atmosphere exerts on the liquid in the
basin below. The liquid and the sealed tube would fall
until the weight of the column was equal to the
(31:45):
atmospheric pressure, and then it would float and fall no more,
leaving mostly a vacuum in the space above. However, there
was another question. There was the question of what is
causing this. It was important to demonstrate that the vacuum
hume was not the thing exerting the force. Tori Shelley
did this with another experiment involving two mercury tubes, one
(32:08):
with a sort of bull on the sealed top end,
and the bulb would mean that a greater volume of
empty space was left at the top when the liquid
fell after the bottom was unplugged. So would that make
the mercury fall to a different level, And it turns
out the extra empty space did not matter at all.
The liquid fell to the same height regardless, So the
(32:32):
force exerted on the column of water in the pipe
or the tube was not a pull from the vacuum.
It was not a pull proportional to the amount of
vacuum created. It was a push proportional to the relationship
between the atmospheric pressure and the density of the liquid.
And this was further demonstrated in experiments performed by Blaze,
(32:52):
Pascal and uh and I think with some input from Descartes,
but Blaze, Pascal and collaborators testing a sim millarier experiment
at different altitude, so you might you test it at
the foot of a mountain and then go up to
the top of a mountain and test again and see
if there are differences. And indeed they found that higher
up on a mountain, the column of mercury would be
(33:13):
lower because the atmospheric pressure was lower. And in fact,
these experiments in the apparatus used the apparatus what's the
plural of that apparati or apparatus is anyway, they this
stuff went on to become the basis of the invention
known as the barometer, which is used to detect atmospheric pressure,
and for much of history, one of the most common
(33:36):
liquids used in it has been quicksilver or mercury. So
people here in the seventeenth century had learned a number
of things. Air has weight, the atmosphere does have weight,
and it presses down and this affects all different kinds
of fluid dynamics, enclosed containers, and at least in an
approximate sense, vacuums can be created. But the scientific story
(33:59):
does not stop there, and maybe in the next episode
we can get into a little more detail on that history,
because there's plenty more. But also we've got to talk
about psychology and horror. Vakawy because I don't know about you,
but you ever have that creepy feeling when you're reminded
of like walking around at school when there was nobody there,
(34:19):
or any other place when you were a kid that
normally had people in it, but then there were no
people in it and you were there and it just
didn't feel right. I think about that all the time. Yeah,
And of course this this plays into a lot of
our our horror movies as well, and a lot of
our fantastic horror scenarios. So we'll discuss some of those.
But but you know this, coming back to this, this
realization that the air has weight, that atmospheric pressure is
(34:43):
involved in these observations. Um, it's it's something that I feel.
Even as modern humans. We have to remind ourselves with
this time and time again, because we can also fall
into that line of thinking where we think of an
empty room is empty. We think of a clear sky
as being empty. Uh. But of course none of those
things are empty. All of those things are completely filled
up with air exerting a pressure on us, but a
(35:06):
pressure that is so ambient that we do not register
it as being pressure. Absolutely, And the way that this
pressure affects other things, say like chemical properties. I think
about the boiling point of water and how that's affected
by atmospheric pressure at different altitudes, and how that affects
something is mundane as cooking, How like cooking has to
be different at different altitudes. Yeah. Ultimately we have to
(35:29):
realize that we are creatures that evolved to reside within
an atmospheric body. And uh, and and even then only
certain parts of that atmospheric body. And then if we
want to bring fire with us and use it to
boil matter to eat, we have to take into account
that it's going to boil differently depending on how far
(35:50):
up into that massive body of air we travel. We
discussed this in a couple of episodes a long time ago.
I think maybe they were the ones about sacred experiences
on mountaintops people have had. But the fact about how
basically like you can't boil potatoes on top of Mount Everest.
People have tried. You try to boil food to cook it.
(36:10):
The problem is the boiling point of water after a
certain altitude gets too low, and so your water is
boiling in the pot, but it's not hot enough to
cook your food, Like boiling water is no longer sufficiently hot. Wow,
And of course it's boiling. Can't get any hotter than boiling,
so you're just stuck like it won't cook. It's hard
to come up with a response to that. I've forgotten
(36:31):
about that tidbit regarding cooking potatoes on Mount Everest for
some reason. That's that's um, that's that's That's almost more
mind blowing than anything we've we've discussed in this episode,
I guess, because it comes down to what we were
talking about earlier, like the perceived world, the world we
can relate to, versus the the world that seems to
(36:52):
exist only within the the lofty conversations of philosophers and
scientists like the experience of boiling potatoes but not being
able to cook them through that boiling like that feels
like the Twilight Zone. That feels like something that shouldn't be.
Rod Serling is kind of a talking to you about this. Yeah, alright, Well,
(37:12):
we're gonna go and close this episode out, but we'll
be back with more discussions of the vacuum, the void,
and so forth in the meantime. Right into us. We'd
love to hear from everyone out there. Uh, what are
your thoughts about some of the ideas we presented in
this episode, and hey, we would we would love to
hear your cooking anecdotes from from different altitudes if you
(37:35):
have some of those right in. Uh, we'd love to
hear about your your mishaps with boiling potatoes and mountaintops.
I know we have some mountaineers out there, Yes we do. Yeah.
Reminder that Stuff to Blow Your Mind is primarily a
science podcast with core episodes on Tuesdays and Thursdays. On
Monday's we do a listener mail episode, on Wednesday's we
do a short form artifact or monster fact episode, and
(37:55):
on Friday's we do Weird How Cinema. That's our time
to set aside most serious concerns and just talk about
a strange film. Huge thanks to our audio producer J J. Pauseway.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at stuff to Blow
your Mind dot com. Stuff to Blow Your Mind is
(38:24):
production of I Heart Radio. For more podcasts for my
heart Radio, visit the iHeart Radio app, Apple Podcasts, or
wherever you listening to your favorite shows.
Stuff To Blow Your Mind News
Hosts And Creators
Robert Lamb
Joe McCormick
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
The Joe Rogan Experience
The official podcast of comedian Joe Rogan.