The Earthquake Detector

How does earthquake detection work and when did humans device the first method of detecting them at a distance? In this Invention two-parter, Robert and Joe first discuss the mysterious invention of ancient Chinese polymath Zhāng Héng before moving on to modern innovations.

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Episode Transcript

Speaker 1 (00:03):
Welcome to Invention, a production of I Heart Radio. Hey,
welcome to Invention. My name is Robert Lamb and I'm
Joe McCormick. So let's begin by stating the obvious earthquakes occur.
Is that obvious if you've never experienced one, Well, that's
the interesting thing, right, because you know, I obviously I

(00:23):
know that earthquakes occur. I I know people who live
in parts of the world where where earthquakes are fairly common.
There was some news story, I think it was just
within the past couple of weeks, that some regions of
California just had like continuous shocks going on, and I
was watching people on social media, you know, react to
it and even mark themselves safe and so forth. But

(00:45):
it violates my expectations because I usually when I imagine
an earthquake, I imagine that something something that happens for
a few seconds and then is over. Yeah, it's uh.
I think the other interesting thing about it for me
personally is that I don't think I've ever experienced in
our quake like. I've always either resided in parts of
the world where there's little seismic activity. Uh, and in

(01:08):
whatever seismic activity I was privy to I just didn't notice,
you know, like, wasn't a significant enough quake. Yeah, I've
never noticed experiencing an earthquake. I'm sure there have been,
you know, detectable shocks where I was at a time,
and not detectable by my brain. Right. So it's one
of those things where if if if I did not,
you know, based on the science and based on other

(01:29):
people's reports that they occur, you know, it would not
even be real to me. But but but they do occur,
and this would have been something that would have been
obvious to humans in ancient history, at least those that
that resided in areas where the rumblings of the earth
could be felt, could be you know, observed in some
fashion or another. And that's something that we certainly have

(01:51):
learned over time, is that earthquakes are not just random.
They don't occur just anywhere with the same frequency. They
occur specifically along line of heightened geologic activity on on
the Earth's surface. Right. I think everyone probably remembers some
of this from from from their their science textbooks and
the geology textbooks. The basics of plate tectonic theory, the

(02:11):
idea that the Earth's tectonic plates are constantly rubbing up
against each other, and these edges are are a place
where a great deal of exciting geologic activity often occurs,
and sometimes these plates slip, releasing energy in the form
of seismic waves. This happens every day, and most of
these quakes aren't even observed. But then, of course larger
quakes can and do occur, and they can prove quite devastating,

(02:34):
especially to human constructions, human habitats, human city cities, especially
cities can fall, rivers can run backwards, catastrophic tsunamis can
rise up from the ocean. Yeah, and this is why
the idea of an earthquake detector is so interesting, or
just one of the reasons anyway, because if you experience
an earthquake, there's no doubting what happened, especially is it

(02:57):
if it is of significant force, you know, significant magnitude,
And if you're not close enough to feel one, then
you'll only know about it if you hear about it,
if someone travels along distance and says, hey, the earth shook,
you know, across the province or across the empire. And
so when we consider the possible invention of an earthquake, detector.

(03:18):
I mean, really, this is the thing kind of thing
that's only necessary if, first of all, you need to
know if quakes are occurring somewhere far away, such as
on the other side of an expansive country or empire. Also,
it would be good to know if you need to
know about the occurrence of smaller quakes that might otherwise
escape notice, because again, not all earthquakes are going to

(03:39):
be of a magnitude that you're just gonna notice what's
happening as you're going about your daily business. They might
also be useful, though, if you need to in some
systematic fashion gather data about earthquakes, right, and yeah, that
comes to my next point. If you're if you're determined
that there's a pattern to seismic activity, and the detection

(04:00):
of one helps reveal the pattern and possibly even predict
future quakes, then this is certainly a case where it
would pay off to be able to keep track of
all sorts of seismic activity, from the smaller occurrences to
the larger occurrences, and attempt to try and figure out
the pattern of these occurrences. This is an important point
because for some reason, I often seem to notice people

(04:23):
getting the idea of earthquake detection and earthquake prediction mixed
up as as if one and the other sort of
the same thing, And they're obviously extremely different things, right,
I mean, they're they're connected obviously because you need to know,
you know, sort of have an idea for the frequency,
and then of course if you know a large earthquake
has occurred, then you know, well that aftershocks will occur,

(04:46):
that sort of thing. But but yeah, there does seem
to often be a confusion between detection and prediction. But
it does seem that detection is going to be necessary
if we need a good science of prediction. But of course,
for the most of humanities time on Earth, it's safe
to say that there was no need to bother with
quake detection. If a quake worth knowing about occurred, you'd
know it, and localized existence didn't really require, you know,

(05:09):
seismic knowledge of far flung lands. But of course, brawling
empires did emerge along with the veraryous sorts of cities
and works that were vulnerable to seismic destruction, and his
brilliant minds began to unravel the world through pattern recognition.
They of course turned their minds to the tremors in
the earth. Awareness of quakes certainly goes back to prehistoric times,

(05:29):
but it's the sort of natural disaster that plays into
various mythologies, you know, attributed to the power and anger
of such gods and goddesses as Loki Poseidon the Giant,
also various monsters such as the giant Japanese catfish Namazoo,
and of course the movements of various world animals that
carry our world on their back, you know, be at

(05:51):
a you know, a turtle or what have you. Uh,
you know, that is sometimes in the in the mythology
reason for the shaking of the earth. Yeah, I mean
very often, uh, not to over generalize, but very often
earthquakes are interpreted as some form of divine judgment or punishment. Right,
But it does raise the question, what is the oldest
historical record of an earthquake? You know, Like I said,

(06:13):
clearly we've known about them for ages. They factor into
our our our mythologies. Uh so as you know as well,
discuss record keeping as vital to understanding seismic activity, especially
as that record keep keeping stretches beyond the limits of
an individual lifespan. But but one of the answers takes
us to eastern China's um Tai Shan Mount Thai, which

(06:33):
is uh about and it takes us back about either
three thousand, seven hundred fifty or three thousand, eight hundred
and fifty years ago. It was recorded in the Bamboo Annals.
This was a text that was interred with with Kings
Young of We who died to b C. And then

(06:53):
this was rediscovered in two though I should point out
that there there has in the past been some discussion
among Eastern scholars regarding authenticity because basically, we have the
lost remains of an ancient court document that was written
on bamboo slips, and then the copies seem to contain
some you know, spurious information. But if we're still talking
about you know, we're still talking about very ancient writings

(07:15):
here and some of the few surviving writings from this
time period. I think one thing that's interesting about earthquakes
as a problem we face is that it's clearly something
that became more dangerous and more destructive to humanity the
more our civilization develops. Basically, the worst thing about earthquakes

(07:38):
for humans is that humans tend to build buildings and
buildings tend to be rigid and not very good at
resisting earthquakes, and so we go in the buildings, and
then the earth shakes and the buildings fall on us
and kill us. If you're in the middle of a
meadow somewhere and there's an earthquake, it's probably not gonna
hurt you. Now if you're standing by the you know,
the side of a river or in a swamp land.

(07:59):
I mean, there are various cases where where yes, you
could have something more die or happened, or a tsunami. Yeah,
I mean, it's not that there are no natural dangers
from earthquakes, but it seems that we very much multiply
the fatality risk and injury risk of earthquakes by putting
ourselves inside rigid human made structures out of stone and
wood and stuff. Absolutely. And then again, when when you

(08:20):
have you know, true kingdoms rising up in sprawling empires,
you have this situation where like one area becomes it
comes to depend on another. And so it's not just
a situation of well, sometimes the earth shakes and sometimes
cities fall, but why can you do no, You'll have
an invested interest in what's going on in these other places. Yeah,
And that is often how earthquakes show up in the

(08:42):
most ancient historical records, is like basically just they They
show up as the records of the destruction of cities
and human structures. It's like, well, those walls fell down.
What can I tell you? Either our army was magnificent
or maybe they were just extra sinful. But for some
reason the earth shook, their walls fell down. It was
probably got Yeah, and there are often religious interpretations to them.

(09:04):
I want to cite one example of an ancient earthquake
that was recorded in history specifically because of its damage
to specific physical structures and so. And this would be
an earthquake in two b c E that is cited
by ancient historians as the cause of the destruction of
the Colossus of Rhodes, also known as the Colossus of

(09:25):
the Sun, one of the most interesting monuments of the
ancient world. So the colossus was considered one of the
seven Wonders of the world by several ancient authors. It
was a giant statue of the sun god Helios, the
patron god of the island of Rhodes, and it was
made of bronze and reinforced with iron. Scaffolding and stone blocks,

(09:46):
and it stood guard over the men Dracian harbor. It
was built by a sculptor named Charis of Lindos, and
it was it was around the beginning of the third
century b c. Built to commemorate the victory of Roads
with the with the help of Ptolemy against the invading
Macedonian army. So Roads withstood a siege. They were victorious.

(10:09):
The Macedonians left left their siege equipment behind, and the
people of Roads celebrated by building this statue. Now we
don't know exactly what it looked like or exactly where
it was placed. There are some indications that it was
posed with one hand shielding its eyes, as if, you know,
trying to block the sun, which is funny because but

(10:32):
then also in the other hand may have been holding
some kind of garment or piece of cloth. Uh. There's
slightly different estimates about its dimensions, but the historian Robert B.
Kebrick endorses the idea that the statue was probably about
a hundred and ten feet or about thirty three point
five meters tall, combined with a pedestal of about fifty
feet or about fifteen point two meters. For a total

(10:53):
of a hundred and sixty feet or about forty nine
meters in height, which is approximately the size of the
Statue of Liberty. Uh So, if you've seen depictions of
the Colossus of Rhods straddling the entrance of the harbor,
I'm sure you've seen this in pictures, so that ships
would have to enter and leave passing underneath and between
its legs. Those are from later interpretations by like medieval

(11:15):
and early modern writers. They're almost certainly incorrect given the
structural and engineering limitations at the time. You can only
do so many things with bronze in third century b C.
And making a giant like bow legged sun god spread
his legs over the water, that's not one of them.
Uh So, the colossus was probably standing posed somewhere that

(11:36):
looked out over this popular trading port, and despite its
reputation and the fawning descriptions of ancient travel writers, the
colossus only stood for about fifty to sixty years. Ancient
sources indicate that it was destroyed by an earthquake that
rocked the island of Roads in about to twenty five
or two twenty six b C. And according to the

(11:58):
Greek geographer and his story and Strabo. It was broken
off at the knees at the time of the earthquake,
and then it toppled over, and the remains of the
statue were left on the ground where they fell, because
an oracle gave a pronouncement forbidding it to be raised
up again. And apparently it stayed that way for hundreds
of years, just toppled over at the knees. Plenty of

(12:21):
the elder later in the first century, Ce writes about
the ruins of the colossus left by the earthquake, and
he says, quote, where the limbs are broken asunder, vast
caverns are seen yawning in the interior. So I wonder
if people would go inside the fallen statue of the
god kind of urban explorers of the ancient world, I
guess exactly uh. And so the ruins of the god

(12:44):
Helios lay where they fell, apparently until around the seventh
century c E. When they were broken up and sold
for scrap by an invading army. So we have no
physical remains of the colossus of Rhodes's just gone. We
have these ancient accounts of what would have looked like.
I mean it based on the idea that it would
have been about the size of the Statue of Liberty.
I mean, the Statue of Liberty is very impressive to see,

(13:05):
you know, rising up out of the myths and all,
so one can imagine it would have, you know, certainly
struck a chord with travelers back in the day. Oh
and just a reminder too, I mean, the Statue of
Liberty is also it is a goddess. We often kind
of forget what it actually depicts, but it's the goddess Libertus,
the goddess of liberty. Huh. You know, I don't think

(13:27):
I knew that. Actually, I don't think I could have
told you that. Yeah, I I usually don't go check
it out, but it was recently in New York and
had some some family with me, and we went and
checked it out. And it is it is neat to
be reminded of just how you know, how impressive the
statue is again, especially if you see it kind of
emerging from the fog, kind of struggling to make itself. Uh,

(13:48):
you know, seen in this country. You know, I totally
know it isn't true, but I realized I just think
of it as a statue of him a Goldman, I
guess because the poem. Um. Yeah, but any well, yeah,
I mean, this is fascinating that this famous wonder of
the world, it was actually only standing for like fifty

(14:09):
or sixty years, and then for hundreds of years, you know,
ten times as long as it was standing, it was
just sitting there on roads, toppled over at the knees,
waiting for somebody to come busted up and sell it
for scrap. Yeah, and we're still talking about it. We're
still talking about it. Like you hear someone talk about
the Colossus of Rhods. You think of this, uh, this

(14:29):
fantastic creation, this this fabulous construction. And yeah, it was
only up for a very very brief period of time. Yeah.
Another huge earthquake in the ancient world was in seventeen CE.
It damaged to destroyed at least a dozen cities in Lydia,
which was a huge province in the western part of
Asia Minor which is now Turkey. Um, but I think

(14:50):
we should turn back to China after a break, because
then we will get into discussing our sort of featured
inventor for the episode today. Alright, we're back, so yes,
our featured inventor. For today, it was a man by

(15:11):
the name of Zhong Young who was a Chinese polymath
and court astronomer in the Eastern Han dynasty. Uh. He
would have lived seventy eight through on nine C. And
he served the emperor's uh andy and Shundi, and this
would have been combined reign to one, and his role

(15:36):
was important. He tended to the calendars and celestial events,
aiding the emperor, who of course ruled at the mandate
of heaven in manain, maintaining the balance between cosmos and
civil life, which is a very important connection uh in
in in in Chinese culture and especially in the rule
of this time. And Zong Hoang performed these duties during

(15:57):
what some call the Golden Age of Chinese history, four
centuries of economic prosperity that saw the traffic of goods
and ideas across the Silk Road. He was an inventor
and and really an early scientist yeah, and a poet
uh So this was interesting. He had like a whole
literary career like before he became interested in the sciences. Uh.

(16:18):
It seems about around the age of thirty. He had
a early career as a poet and literary scholar and
a civil servant in his in his home area of Nanyang,
and I was like, okay, so I gotta find some
of his poems. I looked up some of his poetry,
and one poem I found by Jianghang was called the
Bones of Zwangzi, translated by Arthur Whalley, and it's pretty great.

(16:40):
This is from a section of the poem where the
bones of a dead man are speaking to a traveler
who comes upon them, and the bones say, of the
primal spirit. In my substance, I am a wave in
the river of darkness and light. The maker of all
things is my father, and mother have in his my
bed and earth, my cushion. The thunder and lightning are

(17:04):
my drum and fan, the sun and moon, my candle
and my torch, the milky way, my moat, the stars,
my jewels. With nature. I am conjoined. I have no passion,
no desire, wash me, and I shall be no wider
foul me, and I shall yet be clean. I come
not yet am here, hasten not yet m swift. That

(17:26):
sounds like a description of like a mystical or psychedelic experience,
a lot of oneness with the universe. Stars are my things. Yeah,
conjoined interesting. But eventually, after his literary career, his interest
turned to the sciences, which was chiefly astronomy and mathematics,
and he gained renown for his expertise in these fields,

(17:47):
and this led him to a position in the Imperial Court,
which he entered around one twelve CE, where he was
eventually promoted to the position of head astronomer a few
years after that, and he went on to do all
kinds of stuff. Yeah. Just some of the advancements that
he made included he estimated the value of pie as
the square root of ten or three point one six

(18:09):
to two. That's pretty close. Yeah. He allegedly invented an
odometer in the form of a weegeled cart that would
mark Chinese miles. Okay, so odometer is length measurement, yes,
or distance measurement, it's the same thing. He also wrote
a treatise called ling Sean Mystical Laws that explained the

(18:30):
structure of the cosmos is that of a Henz egg.
So the Earth is the yolk and the heavens are
the egg white containing the movements of the moon and
other celestial bodies. Yeah, I I found a quote directly
from Mystical Laws where he explains this. He says, the
sky is like a Henz egg and is as round
as a crossbow pellet. The Earth is like the yolk

(18:52):
of the egg, lying alone at the center. The sky
is large and the earth is small. And I wouldn't
have thought you would need to make that distinction, and
that the sky is large and the earth is small.
But maybe that is a meaningful distinction in ancient cosmology. Yeah,
I mean, yeah, it's one of those things we we
tend to take for granted, right. Uh. And also I
think in addition to that, he believed that the sky

(19:15):
was suspended on a vapor on the waters, so it
was like resting on waters. Uh. There's a lot of
great skywater and lots of ancient cosmological systems. But so
while he was wrong about conceiving of the Earth the
universe geocentrically with the Earth at the center, he was
correct in understanding the Earth is a sphere surrounded by

(19:35):
sky in an uh, and in an understanding that the
moon and other planets were also spherical. And he had
several insights about the moon. Yeah, he theorized that the
moon did not emit light itself, but merely reflected the
light of the Sun. So to quote from the mystical laws,
the sun is like fire and the moon like water.

(19:56):
The fire gives out light and the water reflects it.
And Jong Hung used observations of a lunar eclipse to
conclude that both the Moon and the Earth are spheres,
and that the Moon merely reflects the light from the Sun, which,
of course you can conclude if you you know, critically
observing eclipse, because the Earth is blocking the light from
reaching the Moon and thus reflecting back on us. To

(20:18):
see the Earth's shadow pass in front of the Moon
like that, you can draw the conclusion that the moon
doesn't actually emit light. And he built an armillary sphere
or celestial sphere to illustrate these ideas. It was made
of bronze, and it mapped thousands of stars, and it
was powered by a water clock, so it was mechanical.
It moved um and you know he was he was

(20:38):
not the first to build one of these, but the
invention does seem to have and it seemed to have
its earliest roots in Chinese astronomy. So while he was
not the inventor, we can uh, you know, most commentators
do point to Chinese history as being the place where
the sort of technology was born. I'm interested in the
idea of so the it was moving the objects in

(20:59):
the heavens by having water emptying out of a vessel. Yeah.
I would actually love to come back and discuss water
clocks in greater detail or just clocks, and I mean goodness,
we could do a whole series on timekeeping technology in
the future. But but water clocks, particularly some of the
various Asian varieties are are very fascinating. I just found
out today for the first time. You know, the ancient

(21:20):
word for water clock the clipsidra. You know what that
comes from, clips that meaning theft and hydra meaning water
stealing water. You're stealing the power of the water. Yeah,
it's the water clock is the water thief. It takes
away the water and this measures the time. But despite
all of his achievements, not everybody liked Jong Hung. He

(21:43):
apparently faced opposition from other scholars and courtiers. Apparently one
major reason for this controversy had to do with reforms
to the imperial calendar that Jonghan introduced or oversaw. The
introduction of around the year one twenty three, and I
was trying to understand this better. Some sources claim that

(22:04):
he got into trouble basically by making reforms to the
calendar to bring it in line with astronomical observations. Right,
So he's doing astronomy, observing the heavens. He notices that
the calendar does not match up correctly with his astronomical observations,
and he brings the calendar in line to match them correctly.
And and so I've read some in some places that

(22:26):
that was the problem. I've also seen references to more
arcane religious disputes is the source of the struggles at court.
So I'm not positive how all that resolves. But one
thing is clear. Astronomy was of extreme importance to the
ancient Chinese rulers. It wasn't just for curiosity, it wasn't
just for play, was serious business of life and death. Yeah,

(22:47):
I mean, of course, we we do see this in
in several other major civilizations as well. I mean the uh,
you see this in meso American cultures that the Babylonians, Yes,
I mean the also you know, ancient India there was
this um, this this understanding that you know, the there
are these things happening in in the cosmos, and there's

(23:09):
a connection between what's happening there and what is happening here,
this basic connection that uh, the zhong Hoang's profession revolved around,
like helping the emperor maintain this connection between cosmos and
civil life. Exactly right. Yeah. The ancient Chinese rulers were
often interested in astronomy because they believe that movements in

(23:29):
the heavens gave predictions and ruled over the fates of
people on Earth, even kings or especially kings. Uh. And
we we've talked about versions of this on our other
podcast on Stuff to Blow your Mind. One that sticks
out in my mind is the idea of some Babylonian
or as Syrian rulers replacing themselves with a double if
a lunar eclipse was predicted, this the eclipse kings. So

(23:53):
the basic rationale here in ancient Mesopotamia was that a
lunar eclipse was a death omen for the king, and
if astrologers said lunar eclipses coming up, the king would
temporarily abdicate and go into hiding by becoming a peasant.
And then they would make an actual peasant either like
a prisoner of war or just some random person, a

(24:14):
gardener or somebody. They'd make them the king for a
number of days to sort of absorb the curse of
the lunar eclipse, after which the false king would be
ritually put to death and the real king would return.
And to some extent this hinged on the ancient Mesopotamian
astrologer's ability to actually predict eclipses, Like, you don't want

(24:35):
a curse taking you by surprise. So there were magical
or religious reasons for wanting accurate astronomical information. It was
a magical motivation for real science. That's interesting how they
essentially the the magical thinking that it ends up entangling
the whole just purely observational effort then becomes the mandate

(24:58):
for improving your ability to observe, calculate, and predict the
movements of the heavens. Yeah, and so it seems that
ancient Chinese astronomers or astrologers played a somewhat similar role
in the Imperial court, not exactly the same, but at
least in part. Again, I was trying to understand more
about exactly what this conflict over the calendar and astronomical

(25:18):
observations might have been. And I ended up reading a
really interesting old paper on Chinese astrology by the historian
Shigaroo Naka Yama, and this was published in nineteen sixty six.
But uh, it's got a lot of interesting characterizations of
of like the history of astrology in China. Yeah, I
I read uh this as well, and it's in parted.
It just also has a nice breakdown of what astrology

(25:41):
it was. Yeah. So just one interesting little tidbit. This
might be sort of a tangent, but uh, he writes, quote,
Chinese court astrology consists purely in the accumulation of portents
in the form of celestial, meteorological and seismological phenomenal seismological
also supernova, planetary conjunctions, comets, hail storms, earthquakes, and their

(26:06):
empirical correlation with events in human society which are relevant
to the success of imperial rule. Here is a typical
interpretation from the she She which is records of the
Grand Astrologer historian from about nine DBC. Quote, when Mercury
appears in company with Venus to the east, and when
they are both read and shoot forth rays, then foreign

(26:30):
kingdoms will be vanquished and the soldiers of China will
be victorious. And I think that suggests that that you know,
these are calculations that could could be used in determining
your the course of action with military engagements. The campaigns
help you know what's going to happen and plan for it.
I mean, they probably would not be very accurate, but uh,

(26:51):
they would at least be perceived to have some kind
of revelatory or accurate power. And I also think it's
interesting in the way that it differs from what Nakayama says.
Are later versions of both Western and Eastern astrology, which
are more focused on individualized patterns of fate dictated by
like people's birthdays. This is sometimes known as uh Jenneth

(27:12):
liacal or or natal astrology, and if naki Yama's description
is correct, the oldest, more traditional versions of Chinese imperial
astrology would consist of making calendars of celestial events and
then correlating them to events in the world, specifically events
of interest to the emperor, so that future astronomical positions

(27:33):
could be used to predict the fates of the empire
and its leaders. And it was later that the fate
calculations based on like birth calendars and stuff came in.
But also something Nakiyama says that he writes is that
eventually for periodically recurring portentous events, Okay, so things that
you can predict or happening on a on a pretty
regular cycle, like lunar eclipses and planetary alignments, he writes

(27:58):
that for those things, the calendar or itself became more
important than the actual stargazing and observing of the heavens. Quote,
the goal of astronomy was the production of the official calendar.
Chinese astrologers relied heavily on calendrical indications rather than directly
upon astronomical computations or observations. Counting cycles based on planetary

(28:21):
periodicities could be replaced with much simpler abstract cycles. So
in a sense, there's this idea that they they had
they were kind of getting to the point where they
were they were stealing the calendar from the heavens. Yeah,
just and relying on the heavens less for their calendar
because ultimately what they wanted, what they needed, was the
calendar to govern their decision making, right, So you can

(28:43):
see a weird kind of conflict there. So, like if
you are a reformer as at least several sources, you know,
report that Jong Hung was involved in reforming the calendar
to make it more accurately fit astronomical observations. On one hand,
like if you're the emperor, you would want that, you know,
as you would want that, you would want to be
able to predict things accurately. But also if maybe you're

(29:05):
another astrologer in the court who's used to using the
calendar how it is like you, you might be opposed
to that because it would it would you know, screw
up what you're doing, or it might just be a
general challenge to tradition and kind of rocking the boat. Yeah.
I can also see it be a situation where potentially,
you know, the the the perhaps unstated counter argument would be, uh,

(29:26):
you know, look, let's not go you know, we don't
have to worry about putting the calendar back in the
line with the cosmos. If the calendar is working, like
we're trying to build a you know, maintain a functional
empire based around this calendar, and then here's this guy
coming along and saying, no, no, the astronomical data, uh
says that we should tweak how we're planning out our year. Yeah,

(29:47):
exactly right. Uh. But then again, I mean I wanted
to mention again, I have also read elsewhere that there
were like other concerns that may have motivated his problems
in the court, maybe more like disputes about like esoteric
religio interpretations of the calendar. So it's it's hard, it's
hard to sort out exactly what's what there. But but
basically Jonghang was an astronomer. He was pretty apparently pretty

(30:09):
good at what he did within this astrological context, and
he made some enemies in the court, and this interfered
with his ability to advance throughout the court and have
a successful career. But again, it's it's interesting to drive home,
you know, his role as a scientists, his role as
an astronomer, uh, you know, and to think too about astrologies,
you know, empirical aspects uh that you know we see

(30:31):
in astrology the roots of pure scientific inquiry, the roots
of medicine, et cetera. Yeah, that's exactly right. I mean,
while astrology, I think is rightly considered a pseudoscience, the
history of astrology gives birth to a lot of practices
that become an incorporate elements of real astronomy and are
really science much in the same way that like the

(30:53):
traditions of alchemy, you know, basically doing magic with materials
did in some ways give rise to actual chemistry and
understanding the properties of materials and chemicals. Okay, I think
after we come back from a break, we should address
Jonghong's primary invention for today's episode, which was an invention
that he crafted later in the last decade of his life,

(31:14):
the seismometer or seismoscope. And so we'll do a break
and we'll be right back with the seismoscope. Alright, we're back.
So what is the seismoscope, Robert, Well, the idea here
is that it is an earthquake detector. It's a way
of detecting um seismic activity vibrations in the ground. Exactly. Yeah,

(31:38):
and so yeah, this is the primary invention, uh, alleged
invention that we want to discuss here today. But we
do want to drive home that Yeah, there are a
lot of mysteries about it. Uh, we're not really sure
how this thing was supposed to work, if truly it
did work. But basically the idea here is that part
of his job was of course observing natural phenomena and

(31:59):
then uh, you know, using it to calculate calendars, etcetera,
carrying out these these astrological duties. And one of the
things that he was considering what were the movements in
the earth, the seismic activity, which they did not understand
as we understand it today, but but still it was
it was a noted natural phenomena that that they figured
should be understood and studied. And then of course there

(32:21):
was a connection to with the destructive nature of seismic activity. Again,
if something terrible happened, if there's a terrible earthquake, uh,
you know on the far you know, extremes of the empire,
it made sense for the emperor to know about it
so that you could you could send aid, you know,
or to that location. Well, yeah, in this context and
the astrological context, as we talked about already, they didn't

(32:44):
just think the portents were in the heavens. They also
thought the portents were, you know, storms and earthquakes and
things here on Earth. So the earthquake is not just
as you're saying, is not just a consequence. It's not
just that there is destruction and people get injured. It
also is crucially relevant information to the emperor that might,
you know, tell the emperor some something important about what's

(33:06):
about to happen. And so Yong Hung created what was
called the whole thing Doo doong ye, or the Instrument
for measuring the seasonal winds and the movements of the Earth.
And based on descriptions of this device, it was apparently
an elaborate bronze sphere with some sort of a sensitive

(33:26):
pendulum inside of it. We're not sure about that. Most
of the descriptions apparently just described the exterior with little
or no detail about how it's working on the inside.
There was something inside it, right, But hopefully we'll have
a picture of this or a recreation or an illustration
of what this was supposed to look like on the
landing page for this episode in invention pod dot com.

(33:48):
But basically a big bronze sphere and it has all
of these dragons around the edges of the sphere um
eight of them, eight of them with their their heads
facing down, their mouths open. And then underneath each dragon
uh at the bay on the base of this thing
is a frog. And in the in the event of
seismic activity that this device would detect a bronze ball

(34:12):
would drop out of the dragon's mouth into the frog's mouth,
and you would be able to look at the machine
see which dragon and which you know, which dragon and
frog duo um were engaged, and this would tell you
which direction the seismic activity was in, right, because the
eight dragon and frog pairs were correlated with the cardinal
directions of compass. So you could say, oh, the northern

(34:35):
ball just fell into a frog's mouth. That means there
was seismic activity to the north. So we could send
aid to the north, or certainly we could. We can
put this information into our record keeping. And another aspect
of it is that it was supposed to make a
sound when the ball fell into the frog's mouth. It
was like a metal frog down there also, so you'd
hear a clang, and that's like the alarm that an

(34:57):
earthquake has happened. You go and check, and then you
can see which direction the earthquake came from. Uh. And
there have been attempts to recreate this this thing. You'll
see modern sort of reproductions of it, but they are
by necessity, UH sort of approximate, because we don't know
a lot of specifics about what was going on. Certainly

(35:18):
about what was going on inside. Even the exterior of it,
which we have a better description of is it varies
a good bit between the different depictions, but generally, yeah,
it's some kind of vase or jar, large vessel of
some kind with the eight dragon heads going in each direction,
the frogs underneath them, and then inside is the great mystery,

(35:38):
that's right. And uh, as far as these recreations go,
there was one I believe in the nineteenth century, and
one of the twentieth century, and then a more recent
one will the will discuss as well. Yeah, and it
isn't a wonderfully uh, you know, intriguing looking device When
you see these these recreations, like you just wonder, like
what magic does this thing hold you? Well? I want

(36:01):
to know is there I couldn't find anything about this,
but is there spiritual significance within? Like the Chinese religion
of the time of a dragon spitting into a frog's mouth.
Does that mean something? Or is it just these forms
are there by accident? Yeah, I'm not sure on that.
I mean, obviously you can think to you know the
importance of dragons and Chinese mythology, and you know as

(36:21):
well as you know certainly frogs show up as well,
but yeah, that would be that would be interesting to
hear an answer on. But again, as for you know
how this thing worked, if it worked, we just don't
know for sure. And and apparently a Jong Hong face
skepticism at the time, which makes sense given as we
mentioned that he had enemies of the court. The story

(36:43):
goes that the device just sat there for years, and
you know, people were like, oh, yeah, this thing works. Sure,
I'm sure it would have been like a hilarious thing
to talk about at parties. Yeah, here's all the dragon
heads ready to spit in the toad mouths. And is
then nothing's happening. Yeah, it's just sitting there. But then
the story goes that eventually a ball did drop into
a frog and this was years later. Yeah, this was
years later, but bend, everyone was like, oh, well, something happened. Um.

(37:07):
But then the word arrived to confirm that an earthquake
had occurred in the designated direction, but nobody had felt it.
That was the thing right where the where the detector was.
It was reported that no one had any indication there
had been an earthquake, but then later they got the
messenger from the ravage region. Yeah, because the detector was
in lou Young that was kept China's capital at the time,

(37:31):
and the reported earthquake, according to the history of the
later Han, occurred something like six kilometers away, and this
would have been in the year on, Yeah, and it
would have been to the east, I think is where
they reported. Now, all we have to go on is
literary descriptions from histories of this thing. We do not

(37:54):
have any physical remains whatsoever, none at all. I mean,
it's said that later versions of the advent Shin existed,
but but there are no relics there either, and descriptions
again focused on the ornate outside rather than the inner
workings of this device. And then we had nineteenth and
twentieth century, you know, various attempts to recreate the detector,

(38:15):
but those efforts did not create anything that seemed to
function in a reasonable way. Okay, So you could conclude
from that that, well, then maybe this is just a legend,
you know, or maybe he built something but it didn't
actually work, or people got confused. Maybe a ball fell
once and it just happened to buy coincidence. Indicate where
there's been a well, yeah, one of the questions that

(38:36):
often comes up is like, how would it work? How
would you create something so sensitive? And and then like
and then when there is seismic activity, why is it
just going to set off? It's going to be so
sensitive to seismic activity and yet so focused, so only
one dragon is going to drop its ball right the
direction that that's really weird. Yeah, so how you know,
how would that happen? How? How would you just have

(38:57):
one ball triggered by a seismic event, and yet how
the device capable of detecting the seismic event. Um Again,
there were at least a couple of different efforts to
recreate it, one in eighteen seventy five by Japanese scholar
and then uh by a Chinese museum a researcher in
nineteen fifty one. But I was also reading about a

(39:18):
two thousand five effort by a group of seismologists and
archaeologists from the Chinese Academy of Sciences and and they
they claim to have to have pulled it off. Jamie
Rigg wrote about this in an article for Engadget said,
quote in their version, the pendulum itself doesn't interact with
any levers. Instead, it's suspended above another ball purchased topic

(39:40):
then pedestal. When the pendulum swings, it nudges the central
ball down one of eight channels, where it hits a
trigger system that animates the external dragon mouth. We don't
know this is exactly how Jong's model worked, of course,
but it shows that only a minor reinterpretation of how
the seismoscope is described in his storical text can lead

(40:01):
to the creation of a sensitive direction aware device. Okay,
so we've got some changes there because that that's originally
it's saying there's a ball in all of their mouths,
and this is saying there's just one ball, but some
pendulum inside. It's extremely sensitive, will will swing when there
is vibration in the ground and will knock the ball

(40:24):
into the mouth like down one slide in a particular
direction where the waves are coming from, and then it
will come out of that dragon's mouth, which is different
than what's described, but that seems more believable in sense. Yeah,
it could be kind of close enough that you'd be like, okay,
maybe maybe yeah. Because I was reading in People's Daily
Online from two thousan five, there's an article about the

(40:46):
device that that pointed out that foreign seismologists would often
argue that if the seismograph worked on the principles of inertia,
then again you have to you have to not one
ball that would drop from a dragon's mouth, you know,
so it was you know, traveling north to south, it
would trigger both north and south ball. But again, if
there's just one ball in there, then it seems it's

(41:08):
conceivable that you could have some sort of elaborate pendulum
system that would that would just shoot that ball into
the desired direction. This is an interesting mystery because like
it's in that realm of where, so we don't know
exactly how it worked, if it worked, Uh, we we
don't know to what extent this historical story is true,

(41:30):
but it's not outside the realm of possibility. So it's
one of those things where, you know, I feel like
we we can't skeptically rule it out, but also we
don't really know yet. It's one of those intriguing open mysteries.
It seems feasible that he set out to create a
device to detect earthquakes, and maybe there was kind of
a you know, an internal rationale for how it worked

(41:52):
and how it would work, and then it just simply,
you know, did not fulfill the purpose. I mean, it's
that's possible, Yeah, that I tend to think that's and
then not to discount his scientific you know, integrity at
all and his his genius, because clearly he was a
very accomplished individual who who's who, you know, thought a
great deal about the you know, the movements of the

(42:12):
natural world. But you know, ultimately this might have just
been beyond his abilities to create. But then ultimately, and
then how do you test it out? Right, you can't
just compare the results of this earthquake detection device with
like some other earthquake detection device, right, you had only
the accounts of seismic activity coming in from across the

(42:33):
uh you know, the the the Empire to go on,
and it sounds like there was like one hit, or
at least that's the only hit that we have to
to really compare it to in in the histories, you know,
anything else was you know, it was seemingly lost. So
I started looking into this a little bit more and
looking for you know, other articles about about his invention,

(42:53):
and it got into this area where we really begin
to touch on China's complex relationship with the past. So
Chinese culture is deep and has been called, you know,
the oldest living civilization on Earth. I believe sinologist Simon
lays Uh put it like that. But the Cultural revolution
of the nineteen sixties and in nineteen seventies set people

(43:14):
against what were what they referred to as the Four
Olds old customs, old culture, old habits, and old ideas.
And this too is a complicated area of Chinese sistory
because the exact nature of the Four Olds was ultimately
left to interpretation. Some old things material or otherwise material
or otherwise we're protected, but other things were destroyed, and

(43:35):
it did result in death and destruction. By the nineteen nineties, however,
their rebuilding and restoration efforts were taking hold, and President
ji Jinping has also encouraged a return to traditional Chinese
ideas and what has been described as a cultural Chinese
cultural revival. But it's interesting, uh to put all this

(43:56):
in context with this this alleged earthquake detector. I was
reading a two thousand eighteen China Daily story titled reference
to Zhong Hong's earthquake device removed from textbooks, and basically
it mentions that the device was mentioned of The device
was moved from secondary school history textbooks in China to
primary school textbooks, but it led. But the initial change

(44:19):
led some media outlets to report that it had been
simply removed from the textbooks, which you know, we can
understand that. I mean that these kind of controversies pop
up anytime there's a change to a textbook, right, um.
But the author of this piece then was speaking to
a couple of individuals about it, and I found it
was kind of revealing about how um, particularly Chinese engineers,

(44:42):
Chinese scientists, how they and ultimately the you know, the
scientific education officials view this invention or alleged invention in
Chinese history. So the author, Zeng Jo Shing, they spoke
to a senior engineer at the Sichuan Bureau of Geology
and Normal Resources, and this individual's take was that while

(45:02):
some of the inventions of the of ancient China were
wonders in their own age, that they're quote useless now
and therefore while they are to be remembered, they're not
to be worshiped, which I mean, I I can see
the logic in that. You know, there, you know, you're
you're you're trying to focus on on modern innovations and

(45:23):
modern inventions, like if you just can't dwell on ancient
uh inventions that ultimately we know nothing about the inner workings. Off, well,
I guess I'm against all cases of worshiping technology, especially
though recent technology. I'd be more inclined to worship the
ancient technology that's useless now, right. It also points out,

(45:45):
of course, that the design itself was sketchy, and then
reconnet recreations are also sketchy, you know, like, of course
we just continue to not know how this thing worked
or if it worked. And this was another thing that
this individual throughout is that some people have he says,
and misunderstood what it was supposed to have done, thinking
that it was a predictive device rather than a detector,

(46:07):
which comes back to what you said earlier about just
sort of modern misunderstanding about what detecting an earthquake means.
And as such, he said, you know, some people hype
it up as being superior to modern technology, which you know,
I think that's understandable to like, you're, if you're working
in your given culture trying to you know, it advanced

(46:28):
the sciences, you don't want people pointing back to this
thing from you know, thousands of years ago and saying, oh,
I heard they had it figured out. Then how how
come we've forgotten how to detect earthquakes? I mean that's
like it's like ancient Aliens kind of stuff, where you know,
they say, like, how could the ancient Egyptians have built
the pyramids? We couldn't even build something like that today. Yeah,
I mean this is basically you know, conspiracy theory thinking

(46:51):
and and certainly, oh sorry, therefore it must have been Aliens,
which wasn't It was just really smart, hard working people. Yeah,
I mean, conspiracy theory are ideas like this can be
disruptive to like general scientific understanding of the world, and
that stands certainly stands true in the United States and
the Western world. It's also true in in China as well,

(47:12):
so you know, that seems to be a valid argument.
Um the The author of this um China Daily piece
also spoke to an associate professor of chemical physics at
the University of Science and Technology in China who and
this individual is also a pop science writer, and they
point this individual pointed out, first of all, we can't
be sure if it worked, so it shouldn't be in

(47:33):
the history books. What so, I mean I could see
where you might some might be getting lost in it
might be lost in translation there. But but I I
do see an argument for like, Okay, maybe maybe it
just needs to be a sidebar. You don't you don't
say who invented the seis McGraph. Oh, it was Jong
Chung uh and and and he's the inventor. Oh, I

(47:54):
see like it shouldn't necessarily be be given confident credit. Yeah. Uh,
and yet this individual had the following to say quote.
Yet that should not darken Jong's achievements. There is solid
evidence of the existence of one of them, uh, the
armillary sphere, which helped ancient Chinese astronomers gain knowledge about

(48:15):
observing the sky at night. Besides, Jong's case also shows
a sad fact about China's history, in which scientists were
hardly given any attention. Jong is now well known for
his scientific achievements, but in his era they only cared
about his achievements as a writer as well as a politician.
It is a pity for ancient China's technological progress. And
that's a that's a quote from Yon Lanfung, Associate professor

(48:37):
of chemical physics at the University of Science and Technology
of China. I guess there is a good question there
about the question of we can't be sure if it worked,
so it shouldn't be in the history books. Again, something
might be getting lost in translation there, but like maybe
maybe there is a good question that's relevant to us.
That's like how how important is it to discuss these

(48:59):
kind of like unsolved mysteries of technological history where you know,
someone is alleged to have created something we don't know
for sure, can't say with real confidence whether it actually
worked or how it would have worked if it did.
But it's at least like tantalizing, you know, and you
you want to think it worked, and you want to
try to figure out if it did work how I

(49:21):
don't know. That kind of thing seems important and worth
talking about to me. What also seems important for countering
any kind of conspiracy theories that the people you know
roll out regarding a given piece of ancient technology. It
had to be Aliens and be at the Pyramids or
the you know, an earthquake detector, or is it some

(49:42):
of the things that we've discussed when we did those
episodes of stuff to blew your mind on ancient alien
hypotheses and uh, and some of the the supposed evidence
that that that those writers like to to drag out,
and the sort of the counter argument that was made
by people like Carl Sagan, Like, I think it's ultimate
important to engage those conspiracy theories or you know, those uh,

(50:04):
those hypotheses and say, actually, this is not what the
evidence shows. This is what this thing was. This is
our best understanding of of of what it could have
done and and how it might have worked. Yeah, I mean,
I think that there is a real just missed opportunity
of fascination that goes on when people get into the
ancient aliens thing, because I feel like people get into

(50:27):
it because it seems cool and they want it to
be true, right, you know, it's so interesting the idea
that maybe aliens came to Earth in the ancient past. Obviously,
I think if there were evidence of that it would
be interesting. But isn't it also interesting that like, maybe
ancient people figured out how to do something really difficult
with really limited tools and knowledge and they figured it

(50:48):
out anyway. That's really interesting to me, right, Well, I
mean the other side too, is even if they failed,
it's interesting. So, like you read about Jeong Hong's device here,
and I mean I find my self rooting for him.
I like, I really want this device to have worked
because it makes a better story, right, certainly the whole
thing where people thought he was wrong and then and

(51:09):
then years later it successfully predicts an earthquake. But even
if it didn't work, if it was just this you know,
inspired intelligent attempt to create an earthquake detection device, like,
I still think that's impressive. I mean, that's I mean,
that's still science. Uh. Just you know, unfortunately, there may
not have been like you know, the you know, perfect

(51:29):
situation to really test it out, to rigorously test it out,
and then to improve upon the design. The essence of
science is the fact that failures are important, failures matter.
It right, up your failures and report them. That's that's
useful to other people exactly. And so ultimately, yeah, I
feel good about doing an episode of invention that deals

(51:50):
with an invention that that may very well not have worked.
Uh and certainly we have no answer for how it worked.
If it did work, but may also have worked, and
if so, that's really cool. Now, of course, we've got
seismoscopes of all different kinds today seismometers that some work
on the basis of like a suspended spring or pendulum,

(52:11):
kind of like it's hypothesized that this thing probably did
if it worked others. I think the ones today tend
more often to use suspended magnets so that like tiny
movements of the pendulum can induce current and that can
be recorded by electronic detectors. Uh. Some models use other
methods like lasers or fiber optic cables or you know,
all kinds of other things. And I think this is

(52:32):
a subject that maybe we could return to in the future.
Maybe we could do something on modern seismometers. Yeah, some
of the plans involved smartphones. How we can sort of
use the power of smartphone technology to two more accurately, uh,
to detect and study seismic activity. It remains a fascinating
mystery in the annals of invention. What happened Jung Hong?

(52:53):
Did he detect an earthquake in the second century CE?
What do you think right in? Yeah? Absolutely, uh, And
certainly if you have suggestions for future episodes, let us
know other examples of ancient technology and ancient inventions you
would like to see profile other more modern inventions like, really,
one of our our basic approaches to the show here

(53:14):
is that that all inventions are on the table, you know,
be it. You know, the big obvious things, but also
the smaller, less obvious things, the failed things, and even
the things that that didn't quite come to into existence
at all, or the terrible inventions. Yeah, terrible inventions. Bring
them on. We'd love to hear from you. In the meantime.

(53:34):
If you want to check out more episodes of Invention
the websites invention pod dot com. That's a great way
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to do so. Make sure you have subscribed as well.
Huge thanks to our producers today, Seth Nicholas Johnson and
Maya Cole. If you would like to get in touch

(53:55):
with us to let us know feedback on this episode
or any other, to suggest a topic for the future,
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(54:16):
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