Fritz Zwicky, The Father of Dark Matter

Fritz Zwicky is often described as a genius, but also as a caustic figure. His insights into astrophysics are downright baffling, but his prickly interactions with peers were problematic to his career and his place in history.

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Episode Transcript

Speaker 1 (00:01):
Welcome to Stuff you missed in History class from how
Stuff Works dot Com. Hello, and welcome to our podcast
kind Tracy B. Wilson. Uh And when people talk about
this subject of today's podcast, he's also described as a

(00:22):
genius but also uh, something of a rather caustic figure.
And while he had insights that even today thinking about
sort of how he came to his conclusions their downright baffling.
But he also had a reputation for being pretty arrogant
and rubbing his colleagues the wrong way, which is commonly
cited as having been pretty detrimental to his career. And

(00:44):
this sort of his proper place in astrophysics history. So
we're going to talk today about the father of dark matter,
who was Dr Fritz Wicky. I'm actually kind of amazed
that I did not realize how early he was working,
right somehow, Yeah, somehow I thought dark matter was much

(01:04):
more recent than this. Well, the big confirmation was much
more recent. We talk about a little bit, but he
was onto it way before anybody else was, right, So
to go ahead and start blowing your mind right from
the beginning. Fritz was born in Varna, Bulgaria, on February
eight His father was a Swiss merchant and his mother

(01:25):
was Czechoslovakian, and when he was just six, his father,
thinking that he would surely go into the family business. Uh.
He was sent to live with his grandparents in Glaris, Switzerland,
and the plan was that he would study commerce while
he was there and learn about business. But he did
have a head for numbers, but it turned out that
that interest fell into the areas of physics and non

(01:47):
financial mathematics are really not similar at all in their path.
In nineteen sixteen, he enrolled in Einstein's alma mater, the
Zurich Polytechnic Institute, to study for six and in five
after he had graduated. Uh. And he's said to have been,
you know, very adoring of his his professors that he

(02:09):
thought were genius is Uh. He ended up getting a
grant of an international fellowship from the Rockefeller Foundation and
he used the money to travel to California so he
could work for Robert Milliken as first and assistant professor
and then a professor of theoretical physics at the California
Institute of Technology, which you would know as cal Tech. Uh.

(02:29):
It's in Pasadena, California. And at this point some of
the most exciting astronomical discoveries of the modern age were
happening at cal Tech. The nineteen twenties were just a
huge time for them. So, for example, through the lenses
of the Hooker Telescope, Edwin Hubble was making important observations
about the vast array of galaxies and space in the
expanding universe. And through a couple of large grants, including

(02:53):
one from the Rockefeller Foundation, cal Tech was building, you know,
really advanced instruments and basically developing facilities to remain on
the front line of research in astronomy. So he had
gone to what really seemed like a mecca for astronomers.
But Fritz was a physicist. Uh, the two worlds do

(03:13):
have a lot of crossover, though, and he was excited
by both of the disciplines, and so he thought that
the only course for him was to teach both courses,
and that's how he became the first astrophysicist at cal Tech.
And while he was at cal Tech, he also met
a man named Walter Bada who was a German American
observational astronomer, and the two began collaborating, and some of

(03:37):
that collaboration would become very important. Fritz Wicky came up
with many many theories about astrophysics during his career. His
research and his theories were both just incredibly advanced. So,
for example, Uh, in ninety three's Wicky put forth his
theory that there is in fact a huge amount of
unseen matter in any given galaxy. This is a completely

(04:00):
new idea. Everyone thought that what you could see were
the stars and that that's what was out there. Uh.
But this idea was based on his observations of the
Coma galaxy cluster, and based on the visible matter that
was in the cluster and how it was behaving. He
concluded that there simply was not enough of it if
we only counted the visible pieces to provide enough gravity

(04:23):
to keep these fast moving galaxies together, and that there
had to be something else in the mix producing enough
gravity that kept this cluster from flinging apart. That invisible
substance was what he called dark matter, and he published
this theory in Helvitica Physica Acta. In his own words, quote,
in order to receive an average Doppler effect of a

(04:44):
thousand kilometers the second or more, which is what we
have observed, the average density in the Comma system would
have to be at least four hundred times greater than
that of visible matter. If this can be shown to
be the case, then it would have the surprising result
that dark matter is present in the universe and far

(05:05):
greater density than visible matter. I feel compelled to say again, yeah,
this is he was. He was drawing these conclusions away
before anybody else was thinking about them. It's possibly because
I didn't really learn about dark matter until studying astronomy
in college that in my brain this was a much

(05:28):
more recent theory than it really was. Well, there are
also some other reasons, which is that a lot of
people dismissed him as kind of cockamami. And we'll get
to why as we go on. Uh. But in addition
to this work on dark matter, and building on the
work of Indian physicist Subrahmayan Shandrasakar, who later became famous
for his mathematical work related to black holes, Zwiki and Bada,

(05:51):
working together, described a neutron star. So this is a
collapsed core of a star with an incredibly dense mass.
For sample, According to the National Geographic Online entry on
neutron stars, a sugar cube sized chunk of neutron star
is estimated to weigh roughly one million tons here on
planet Earth, so that's how dense it is. For scientific context,

(06:15):
the neutron had only been discovered a year prior, so
quick review just in case you need it. Positively charged
protons and neutral neutron neutrons make up the nucleus of
an atom, while negatively charged electrons form an orbital cloud
around the nucleus. Yes, so we only knew what neutrons
were for a little while before Zwicky was to what

(06:39):
his colleagues felt like jumping to the conclusion that neutron
stars were, in fact, you know, sort of a larger
scale version of some of the things they had witnessed
at the atomic scale. But really he was just intuiting
some pretty impressive things, uh. And he proposed that as
a star burns out its fuel, it's gravity is so

(07:00):
right that it causes a compression of such magnitude at
the core that protons and electrons are crushed together to
form neutrons. So if you think about particle physics, it's
very similar, just on a much bigger scale. It's also
set the groundwork for his Wicki and Bada's description of
a supernova as a star core implodes, that propels this

(07:20):
massive explosion of the stars outer layers. Such explosions, they theorized,
were also sources of cosmic rays, or high energy sub
atomic particles that travel through space at a velocity that
approaches the speed of light. Yeah, cosmic rays had been
observed before, but no one knew where they came from,
and Swiki and Boada felt like this was where they

(07:41):
came from. The pair first presented these theories at a
conference of other scientists UH in three and as subsequently
they published them as a paper in ninety four, and
that paper about neutron stars, cosmic rays, UH and supernova
has really been described as press and incredibly important to

(08:02):
both physics and astronomy. In the mid nineteen thirties, certain
that supernovas and other galaxies were something that we could observe,
Zwicki convinced the director of the Mount Wilson Observatory to
build a special telescope with a wide field of view
so that he could observe and photograph multiple galaxies at
the same time. That telescope enabled him to identify twelve

(08:26):
supernovas over the course of three years and That work
also gave him really firm ground to stand on when
he went back and asked for an even bigger Schmidt telescope,
and that request was granted. Uh The forty eight into
telescope that was built after this second request was installed
at Mount Palomar, and surveys of the northern sky conducted

(08:46):
with it laid the groundwork for decades of astronomical study.
As thetes stretched on, Zwicky developed a theory of gravitational lenses,
and it was based on Einstein's theory of general relativity.
This theory was that you had a galaxy in your
line of sight, that galaxy could distort the image of
more distant galaxies by bending their starlight. He asserted that

(09:10):
by measuring the distortion that a galaxy caused could then
give astronomers a sense of the weight of the lensing galaxy. Yeah,
which is again, this is in the thirties. This was
a lot of extremely um It almost seems like a
leap of faith to people that that might not understand
his line of logic well. And the idea that the

(09:30):
gravity of something could distort the light of something behind
it is now kind of taken for granted. In the
in the field. I mean, it had been discussed to
some degree prior to that, but he was the first
one that was like, no, this is happening on a
mammoth scale. It's affecting everything we observe. Uh. And while
giving the Oxford University Halley Lecture in ninety eight, which

(09:52):
is an annual lecture that is quite an honor to give,
Zwicky spoke at length about what he called morphology, which
is a systematic approach to studying the structure and form
of scientific and technological topics by analyzing all possible parameters
and solutions to any given related question. And this is
one of those things that he really felt like he

(10:13):
had been doing all of his life, even before he
had a name for it. Uh. And he was founder
and president of the Society for Morphological Research, and in
later life he wrote of morphology quote, I feel that
I have finally found the philosopher's stone in what I
call the morphological outlook and method. So he basically was
trying to explain, like, I know what I'm doing, I've

(10:34):
always been doing it. This is why I'm able to
come to conclusions that other people don't see. I'm just
so systematic and how I approach every possible issue that
I look at that I'm going to eventually hit on
the right thing. Uh. It's an interesting approach and it
is it's very methodical. It makes a lot of sense
when you read about it. It It kind of forming this

(10:55):
matrix of possible outcomes and options for every possible variable
in a situation. It's a lot of work, but it
also does sort of create this beautiful order and structure
to what may have been completely incomprehensible before. Before we
get to sort of the problems with all of these
amazing theories he had being accepted by his peers. Do

(11:18):
you want to take a quick word from a sponsor. So,
despite his incredibly advanced insights into astrophysics, many of the
assertions that Zwicky made in his career really just hit
a brick wall with his colleagues. He had this incredible
neck for finding conflict with the scientific community, and um,

(11:40):
this basically is really attributed to his personality rather than
his ideas. Even though his ideas were very advanced and
hard for people to deal with, his way of presenting
them and sort of dismissing people that didn't get them
is really why he probably had so many problems kind
of gaining ground with um with his work. Okay, almost

(12:01):
any and every synonym for person kitty has been used
to describe Wiki at some point in time. He's often
characterized as being just incredibly arrogant and dismissive of other people.
And he even fought with Boda, who was his real collaborator.
According to astronomer and Bruce medallist Jesse Greenstein's Wicky called

(12:23):
Bota a Nazi at one point during World War Two,
and Bota was infuriated but also afraid of Wicky. Yeah,
apparently from that point on, having the two men in
a room together was not really a viable option ever,
because they would not just bicker, but it would become
extremely heated and very very passionate and angry in a hurry.

(12:45):
While there are many many instances of people saying that
Wiki could be a pill, and that is a very
gentle way to put it, his own feelings about others
in his field are made incredibly clear in his own writing.
It's not a case of like these people are all
saying he was crabby. He It's it's in writing he was.
He said some pretty unkind things Uh, the introduction to

(13:08):
his catalog of selected compact galaxies and of post eruptive Galaxies,
which came out in nineteen seventy one, is basically full
of criticism of his peers, and he calls them out
by name. It's really really bitter in its tone, and
it's full of all kinds of snark like quote again
and again, scientists and technical specialists arrive at stagnation points

(13:32):
where they think they know it all, and he did
underline that in the text. Another was the naivety of
some of the theoreticians at all times is really appalling.
Another is, the most renowned observational astronomers in the nineteen
thirties also made claims that now have been proved to
be completely erroneous. This reshearted real progress in astronomy by

(13:57):
several decades since the said observer has had a monopoly
on the use of the large reflectors of the Mount
Wilson and Palmer observatories, and inasmuch as they kept out
all dissenters and then Uh, this gym. Today's sycophants and
plain thieves seem to be free in American astronomy, in
particular to appropriate discoveries and inventions made by lone wolves

(14:21):
and nonconformists, for whom there is never any appeal to
the hierarchies, and for whom even the public press is
closed because of censoring committees within the scientific institutions. He
makes it a point to clarify that he's the only
person to have clearly stated what a galaxy is, refers
to some scientists at Scatter Brains, and even calls out Hubble,

(14:44):
Body and contemporary Henry Norris Russell and others with very
specific criticisms of the ways their incorrect assertions set back
the study of astrophysics. Yeah, he really does not hold back.
It's it's very clear that at that late point in
his life, he was in his seventies at the time,
he was still just super angry at how he had

(15:07):
been treated. Uh, And it's kind of funny. He includes
in the text of this introduction a letter which was
written by Edwin Hubble to the Scientific Monthly, which had
run a piece about some of the work that Zwicky
and Bada had done together, and in it, Hubble points
out to the publication that an error that they made

(15:28):
about attributing to Dwarf Nebula to Bada instead of Wicky
and Fritz, you know, includes all of this and his
thing about this Edward Edwin Hubble trying to correct this error,
and then he points out that in his opinion, this
is a completely rare instance of gentlemanly behavior in the
field of astronomy, and that he's sort of it's the
exception rather than the rule in his opinion. With all

(15:51):
this in mind, it just becomes really easy to dismiss
this guy as a cranky curmudgeon when reading this rather
infamous introduction. But it's also clear that his bitterness and
anger came from years of having his work dismissed, even
when the same work was clearly being verified and even
used by other researchers. Yeah, I can see where you

(16:13):
would land at this sort of very crabby mindset. You know,
if you're saying, hey, I think this thing is happening,
and people go, oh, you are a crazy idiot, and
they're scribbling the notes down and then using them in
their own work. Belled crazy idiot is no fun. I
would be bitter as well, I think. And as it
turns out, most of Swiki's predictions and theories, which he

(16:34):
arrived at through what he called directed intuition, which is
kind of part of that bigger morphology idea. We're absolutely correct.
While the theoretical existence of neutron stars was validated by
UH work in nuclear physics before then, the first neutron
stars were actually identified in Swiki's lifetime in the nineteen sixties.

(16:55):
He died suddenly on February eighth, nine four at the
age of seventy five. But during the nineteen seventies and beyond,
astronomers were conducting research and making discoveries that continued to
validate what he had been saying during his life. In
the nineteen seventies, Vera Reuben, W. K Ford and other
astronomers were able to verify the idea of dark matter.

(17:18):
That is why you think of it as being a
much later discovery. Vera Reuben is mostly associated with dark
matter UH, and it really was in the seventies, kind
of like the big announcement was always attributed to these people.
So I think that's probably why you think it is
a more recent thing than it was. And then in
nineteen seventy nine, so five years after WIKI had passed

(17:41):
the first gravitational lens UH and and proof that it
was actually working the way he had described was discovered,
and uh, the lensing effects. The lensing effect as Weiki
described it in ninety seven is actually now applied to
measure the universe and its contents with regularity. They're sort
of always exploring the parameters of the universe using uh,

(18:05):
the very concepts of gravitational lens that he set forth
in the late thirties. Fritz Wicky's youngest daughter, Barbarina, has
become his advocate. She's really tirelessly written letters to science publications, bloggers, journals,
and news outlets, pointing out that her father was very
far ahead of his his peers in space research and

(18:26):
in his theories. Yeah, she really wants to ensure that
he gets his due in the historical record. And to
one magazine she wrote, quote, Fritz Wicky revealed a genesis
of astounding cosmological achievements that still illuminate the scientific world.
He was a scientific prophet and the sacrificial lamb for
the provincial judgment of his colleagues. His emendation of intellect

(18:48):
with such apodictic truth and his presages were of such
advance that the standard mind only could falter in their presence.
And while he definitely had some rough edges. Zwicky also
had a really generous streak. When World War Two ended,
he organized the Committee for Aid to War Stricken Scientific Libraries,

(19:09):
and this group, which consisted of Wicky himself and a
handful of volunteers, amassed literally tons of scientific literature and
donated it to libraries that had been damaged during the war.
Zwicky devoted his weekends and spare weekday hours to this
project for years, and he packaged and shipped the materials himself. Yeah.

(19:30):
I read one source that said that it was approximated
to be fifteen tons of materials that he had eventually
shipped over the years, but I couldn't find that validated. Uh.
And In an obituary article about Zwicky, Albert G. Wilson,
director of the Society for Morphological Research, wrote, Zwicky's point
was that there are enough men and women of goodwill

(19:50):
to make such projects a success if only they are
pushed with determination. Availability of funds is not a prerequisite.
He felt that such projects as the book distribution do
more for establishing ties of confidence between different nations and
races that can be achieved by speechmaking, legislation, or high
sounding efforts of international cooperation. He also served as director

(20:13):
of the American chapter of Pestelasi Foundation, which was founded
to foster World War Two orphans. And whilst Wiki had
conflict with his professional peers, the students and staff at
cal Tech really did see a much more affable side
of the man, though he could certainly be a demanding
teacher and mentor. Uh and we have a funny story
about that. The February nineteen seventy four issue of the

(20:36):
cal Tech publication Engineering and Science featured an investigation into
a rumor that students had once managed to pull one
over on him by creating a fictitious student. According to
this legend, in the nineteen thirty one ninety two academic year,
a group of grad students allegedly worked together under the
false identity of an undergrad and an effort to achieve

(20:59):
the impossible, which was to make an a in a
course that's WICKI taught. While the surviving students of that
year all insisted the story was true, the publication never
got swicky side of the story due to his sudden
death during the writing of the article. I find that
to be such a great pity, because I really would
have loved to have here heard his side of bits.

(21:22):
I love that they just wanted to like make him
give someone an a even though he I think never
intended to do so. I just love that that's a
fun that somebody tried to trick him or a group
of people, But it sounds like it was all in
a very kind of good natured sort of way, which
I love. Um So. In his lifetime, Fritz Wicky authored

(21:43):
literally hundreds of articles, numerous books. He held dozens of patents.
He was awarded the Presidential Medal of Freedom for his
work in rocket propulsion during World War Two. The Royal
Astronomical Society of Great Britain gave him their society's Gold Medal,
and he's credited with discovery a hundred and twenty two
supernovas during his work. That number is a record, yeah, unbroken.

(22:07):
He still holds it. Uh. He is buried in Glara, Switzerland,
where there is also his wiki museum displaying some of
his papers and scientific work. There are an asteroid, a
lunar crater in a galaxy named after him, and kermudgeon
er No. He was undoubtedly a visionary. He intuited cosmic
truths that many others in his field simply could not

(22:28):
grasp at the time he introduced him. He introduced them
so so to me, such a fascinating figure, and I
just I have a love for him. I like all
the cranky ones. Those tend to be my favorites for
some parties. Do you also have some listener mail? It's
not cranky at all, It's actually interesting and it's something

(22:50):
we get a lot of. Uh. And it is from
our listener autumn, And she says, Hello, Holly and Tracy.
I am a frequent listener of your podcast. I enjoy
you both his podcast personality, and what I particularly commend
is the evidence of your thorough and reliable research my side,
we certainly try. Uh. This spring, I would be graduating
from university with a degree in theater and miners in
TV Cinema and psychology. With a wide range of hobbies

(23:14):
and interests. I am still a bit lost on the
career finding area. What I would like to know about,
if you'd be willing to share, are your journeys, How
did you come to how stuff works? Where did you begin?
And what we're slash are the passions that brought you
to where you are and the people you've become. Uh,
this is a question we get a lot is kind
of how we ended up doing this, and for both
of us, I think the answer is that it was

(23:35):
quite a circuitous route. UM. I have had a million
different jobs and multiple careers. I've managed hair salons, I
UM worked in a library for more than a decade
as a technical services assistant and UM acquisitions manager for
lack of a better title. UM. I worked in marketing

(23:57):
for an online company. I worked as both an admin
assistant and then a writer at a network for a while,
and then I ended up here UM and I got
hired as an editor, and Tracy and I UM started
podcasting for pop Stuff because one of our bosses heard
us riffing at a party and thought we should try it.

(24:17):
That's really that's exactly what happened. As a completely sure yeah,
at that point, I had already been at How Stuff
Works for several years. I started at a staff as
a staff writer in two thousand and five, and I
guess at that point I was site director and that's
how we landed here. And then as UM well, Deblina

(24:39):
was on eternity leave, I came on as a guest
for history, and then Deblina came back and decided that
she wanted to make a career move elsewhere, and so
then I came on with Sarah for a little while,
and then Sarah also made a career move, and Tracy
joined me here and we sunseted pop stuff. Uh, and
that's how we ended up on history. That the story.

(25:00):
So it's not really a course I could plot out
for anyone. No, And we get a lot of questions
from people that are like, uh, what do you recommend
as far as getting jobs for history majors? And that
is a question we super cannot answer because neither we
nor any other host who has ever hosted this podcast
has a history degree. Yeah. The one person that I

(25:22):
know in my life that has a history degree, and
she actually has a graduate degree in historical studies, is
a librarian. So that's the one instance I know, but
I don't know that that path is going to be
for everyone. She also has a graduate degree in library science,
so uh, yeah, I mean, I think we're kind of
at a weird I don't know if it's weird, We're

(25:45):
at a point it's sort of in terms of the
career world where it's so much different. I think even
than when Tracy and I went through college, that it's
a little bit almost tricky to chart a direct path
to anything, you know, unless you're in like a very
um kind of established field that follows a pretty set

(26:08):
course that has not really shifted, particularly with all of
the economic shifts that have gone on. Like if you know,
you want to be a veterinarian, and you go through
college and you get your biology degree and then you
go to veterinary school and you get your degree in that,
and that's kind of your natural career path. But there
aren't many career paths like that anymore, I think, especially
if you're in like the liberal arts degree area. Well,
even if you're not, like Patrick's degree, his undergraduate and

(26:32):
first graduate degree are engineering degrees, and he is a
librarian now with a separate Master of Library Science to
go with his previous engineering studies. So I think pretty
much everyone I know has a winding, circuitous route to
get to where they are now. Yeah, so yeah, it's uh,

(26:53):
we don't have a direct path. Um. My thing is
kind of like I think how we both ended up
in histories of both Tracy and I have always liked
a lot of aspects of history. We both are readers,
we both kind of just like learning new things, so
way before we were ever in any sort of universe
thinking about a podcast like this, before podcasts even existed,

(27:13):
we were kind of reading about history all the time anyway. Well,
and from a completely practical sense, the past hosts were
leaving and we needed new ones, so it made sense
because we both do like history that it was a
pretty natural transition from that point of view. So that's
the scoop. I'm sorry it's not a direct like, uh,

(27:35):
here's your next step, But the best thing I could
say is just to keep studying all the things you
love and eventually an opportunity will probably present itself to
put some of that into play as long as you're
you know, working hard at other things and making your
way in the world. It's hard for me because I
do like structures, so I wish that I could tell
you here's how. Uh, but yeah, just keep learning everything

(27:59):
you who are interested in learn all the time. Learn
about things you're not interested in, because sometimes those pay
off in other ways. Uh. If you would like to
write to us, probably not for a career advice, because
we're apparently not great at giving it uh, saying work
hard and study things that are interesting. Uh. You could
do so at History podcast at how stuff works dot com.
You can also connect with us at Facebook dot com

(28:21):
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do so at missed in History dot spreadshirt dot com.

(28:41):
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(29:02):
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