[MUSIC PLAYING]
MIKE SHORT: Instead
of saying, analyze
this theoretical problem, I
said, analyze your toenails.
Tell me how much arsenic and
gold you've got in your body.
All we study at MIT is the
natural world and things
we make out of it, so everything
is reducible to practice.
Everything can be real,
if you put in the effort.
SARAH HANSEN: Today
on the podcast,
we're talking about
ionizing radiation
and nuclear engineering.
How do you make these
things real and tangible?
MIKE SHORT: Matter
is a form of energy.
And once that
clicked, everything
seemed to make
sense-- radioactive
decay, nuclear reactions,
all these things.
I remember that aha
moment in this class
that I teach as a second-year
student back in 2002.
And it's those kind
of moments that
made me want to stay in it,
because I feel like, wow, I
really know this field now.
SARAH HANSEN: Welcome
to Chalk Radio,
a podcast about inspired
teaching at MIT.
I'm your host, Sarah Hansen
from MIT OpenCourseWare.
The Nuclear Engineering and
Ionizing Radiation course
at MIT take students from
understanding basic physics
to grappling with the core
concepts of Einstein's E equals
mc squared.
In this episode,
we're going to delve
into how this is
possible, and what
it takes to make a class that's
not only hands-on, but also
capable of evolving daily.
My guest is one of the main
people that makes this happen,
Professor Mike Short.
MIKE SHORT: This course
is all about radiation,
both its origins and its uses.
So this is the first course on
its intro to everything nuclear
that any student
at MIT would take.
And a lot of times for students,
it's their first modern physics
course.
The physics courses that
first-year students take
are often things that we've
known for 100 to 300 years.
And the field of nuclear
physics is still evolving.
We're still using
nuclear radiation spectra
to detect the presence of
water on Mars or the moon.
We're still confirming
our knowledge
of which particles do
and don't exist and why.
So this is also intro
to modern physics.
SARAH HANSEN: So nuclear science
and radiation in particular
are emotionally charged
topics, you know?
You read on the internet claims
like, cell phones cause cancer,
things like that.
How are you preparing students
to debunk pseudoscience
and to really serve the public?
MIKE SHORT: We actually
spent two weeks
at the end of the class
looking at studies
that are false or have
exaggerated claims
and teaching students
what to look for.
So the first 11
weeks of the class,
we teach the students
the fundamentals
of nuclear science.
And then we turn to published
articles, and blogs,
and other things in the field.
And we debunk myths
like cell phones
cause cancer due to
ionizing radiation.
Cell phones don't emit
ionizing radiation.
We debunk myths like,
the tiniest little bit
of irradiation can harm
you, when in truth, we
don't have the data for that.
But a lot of misinformation in
radiation and nuclear science
is incorporated into
culture, into our sort
of collective
consciousness, and even
in what's called the linear no
threshold model, which says,
every little bit of
radiation does harm.
We don't know that
to be true or false,
and it's a good thing we don't.
Because we would need to
have exposed tens of millions
of people to low
levels of radiation
in a controlled study,
which is not something
I think is ethically
correct to do.
It's also not ethically
correct to say
that all radiation causes
harm, because we don't know.
And I want students to both
recognize false science
in the field, and
recognize when we
don't know enough information
to say something confidently,
and be comfortable with
that lack of knowledge.
It means there's
something new to explore.
But if you don't have
something to conclude,
don't draw a conclusion.
SARAH HANSEN: Uh-huh.
How does this connect
to the irradiated fruit
party that have in the class?
What is that?
MIKE SHORT: Yeah.
The last day of class, we often
have an irradiated fruit party,
where I bring in
fruit that could only
be brought into the US
because it's irradiated.
So there are many
fruits that are--
there many different
types of produce,
including fruits,
that are irradiated,
and it's the only known way to
kill all of the insect, viral,
and bacterial pathogens that
can wreak havoc on either people
or on our crops.
An interesting point
of information, Hawaii
and Puerto Rico, despite
being part of the US,
are agriculturally
distinct areas,
and you are not
allowed to simply
import produce from those.
I had an apple confiscated
from the airport in Puerto Rico
when I learned that
to be the case.
However, if you
irradiate foods, like,
this is why we can get a lot
of pineapples from Costa Rica.
We've started
getting mangosteens
in from Thailand, where I
didn't know what that fruit was
until a few years
ago and now, you
can find them at H
Mart in Cambridge.
A lot of this is because
we can kill the pests,
and it doesn't harm the food.
It doesn't make the
food radioactive.
But a lot of this is to
personalize the science.
So when students eat
food that they may or may
not known have been
irradiated, they taste good.
They seem safe.
And it's one of those things
where once it's personalized,
it's not as scary.
When you learn the knowledge and
then you see it for yourselves,
it becomes a lot
more acceptable.
SARAH HANSEN: Yeah,
learning through experience
is very powerful.
What does it mean
to you for students
to develop fluency
in this field?
MIKE SHORT: It's important
to be fluent in this field
because a cursory knowledge
of radiation science
is not enough.
I'd say there are a lot of
self-proclaimed experts--
I call them armchair PhDs--
who have learned a bit of
genuine knowledge, but then
extrapolate it too far.
And that combined
with all the things
we've heard in pop
culture, unfortunately
sometimes from celebrities
spouting falsehoods
about radiation, or
vaccines, or other things
that they don't understand,
people listen to other people,
and people listen to role models
and folks that they look up to.
But it's important to be
fluent and well-grounded
in the fundamentals so that you
can sort out fact from fiction.
And I want every student
that leaves my class
to be able to recognize
something that's incorrect,
even if it's told to them by a
celebrity, an expert, a parent,
a friend, anyone--
that they know what the reality
is, and it shouldn't depend
on the source it comes from.
They should be able to tell
whether it's real or not
and verify if the
source is genuine.
SARAH HANSEN: Uh-huh.
And how do you help students
develop this fluency?
MIKE SHORT: So it starts
off with the fundamentals
of radiation science.
So like any class, we
teach all the fundamentals
from well-established theory.
But along the way every week, we
have labs and personalisation.
Like, for example, the
first day of class,
I ask students to bring in
their toenail clippings.
[MUSIC PLAYING]
And they usually say,
that's disgusting.
What are we doing?
And I say, you'll see.
We're going to put
them in the reactor.
And we irradiate their
toenail clippings.
And because to some degree,
you are what you eat,
some of the elements which
we eat and we don't want to,
things like arsenic,
or selenium,
or chromium, some of which
can be good in small amounts,
bad in large amounts--
others like arsenic,
I'm not sure
if there's a good use of it--
get incorporated
into our toenails.
So we activate those toenails
by putting them in the reactor.
They absorb neutrons and give
off characteristic gamma rays,
giving away how many
atoms of arsenic,
and selenium, and such are
incorporated into the toenails
with striking precision.
And so we're able to tell
where students come from based
on analysis of their toenails.
We had one student who had a
lot of gold in their toenails.
And I said, I thought I asked
you guys to clean these off,
remove any polish.
And the student
said, yeah, I did.
But I live near a gold mining
town, and it's in the water.
SARAH HANSEN: Wow,
that's so interesting.
MIKE SHORT: So that's
what I mean by personal,
is they discover
things about themselves
through nuclear science.
In the problem sense,
instead of saying,
analyze this theoretical
problem, I said,
analyze your toenails.
Tell me how much arsenic and
gold you've got in your body.
SARAH HANSEN: Right, right.
So in the course,
you make a point
of saying that the
method of instruction
is often context first, theory
second, and then context again.
How does that relate to
that method of instruction?
MIKE SHORT: This is an example
of that method of instruction.
I like to start by
opening knowledge gaps
rather than spouting
theory that someone.
It doesn't usually stick if I
just say, here are some facts.
Learn them.
That's usually in one
ear, out the other,
if they're listening at all.
But when you show someone
something surprising,
they're fully engaged.
They're always
multi-sensory engaged.
They're listening.
In a lot of cases, they're
touching, in some cases,
even smelling.
Taste is the sense
that we don't tend
to engage in nuclear
science, with good reason.
[CHUCKLES]
But you can sense, and
feel, and hear a lot
of things in nuclear science.
Like yesterday, I was with
one of my graduate students.
We were looking at some
highly irradiated materials
for a reactor in Idaho, and
we heard this little faint
buzzing noise in
the Geiger counter.
And if you put your ear
up to the Geiger counter
near the radiation
source, you can hear
tiny electrical discharges.
You can hear the
detector working.
And then I want the student
to say, why is that?
Why do I hear this fuzzy
noise near the detector
when it's working?
Then when you explain why,
students tend to remember.
Not too many people learn
well by being lectured at,
but everyone learns well
by opening knowledge gaps.
And you're effectively pulling
the information in rather
than us pushing it
to the students.
Something I learned
from a mentor
here is you can't push a string.
You want knowledge
into a student's brain,
they've got to pull it.
You can't push it.
SARAH HANSEN: You made a choice
in this iteration of the course
to offer students the ability
to do analytical homework
or take-home, hands-on labs.
How did that work out?
What does that look
like in practice?
MIKE SHORT: Interestingly,
I spent all this time
making these optional labs.
Nobody did them.
So the next couple
of years, I simply
made everything mandatory.
The students said they
loved the flexibility.
They're really psyched
that I put in all this time
to do the labs.
But it wasn't for a grade,
so they didn't do it.
And so that's when I learned.
If it's not graded, it's
not going to get done.
So I made all the
labs mandatory.
I cut out a little
bit of the analytics
in favor of adding context
before and after the theory,
and retention went up.
Grades went up, on average.
And the course
evaluations went up, too.
So anything numerical
we can get improved--
and in my subjective
opinion, so did
the students' knowledge
of what's happening.
And that, I get
from my colleagues,
because I track these students
as they progress through MIT,
through our department.
And my colleagues who
teach further-on courses,
the more advanced ones,
can tell me whether or not
the students really
know the fundamentals
that they're depending on.
So far, things have
been getting better,
but it requires planning.
And it also requires
a lot of thinking,
where I'll look
through my syllabus,
and I have an empty column
where the user doesn't
exist in most syllabi, which
is, what is this week's
hands-on instruction?
And I try to make
sure that's full.
So another example is
if you want to know,
do you have real diamond rings?
When we get to reading
electron spectra
and characteristic
X-ray spectra,
I could either give them a
problem from theory, which
is boring, or I can run
some standard for them,
where they know what to expect.
Or I can say, that's
a nice diamond ring.
Do you want to
know if it's real?
And the student invariably
says, absolutely, I
want to know if it's real.
SARAH HANSEN: Right.
MIKE SHORT: So we
have the student
take the controls of
the electron microscope
and analyze it to see, does that
diamond emit zirconium x-rays?
Because if it does,
it's cubic zirconia.
If it emits silicon x-rays, it's
moissanite or silicon carbide.
My favorite one was
this day happened
to fall on parents' weekend.
So I asked the students, does
anybody have a diamond ring?
And one of the students'
mothers said, oh, yeah.
Let's check my engagement ring.
And her husband
was just, oh, gosh.
What's going to happen?
What's going to happen?
He thinks he bought
a genuine ring.
It turned out to be real.
We had the proof.
SARAH HANSEN: OK, that's good.
[MUSIC PLAYING]
Mike, can you tell us about
the radioactive scavenger hunt?
MIKE SHORT: Sure.
I challenge the students to
find the most radioactive place
in Boston.
And each of them had
to go in teams of two
and pick a place that they
thought would be radioactive
based on what we'd learned
about where you find radiation.
So radiation, a lot of
it comes from space,
from cosmic protons
that hit the atmosphere.
So some students thought, I'll
go to the tallest building,
and I'll probably
get more radiation.
Others had read about
radon underground,
because there are isotopes
of radium emitting radon gas.
And so they thought, we'll
go down into the subway,
get as low as we can go.
Other students looked at the
relative amount of radiation
in different building materials,
like wood, clay, marble,
granite, and they went to the
most granite-dense locations
they could find, or the
ones with the most marble.
And those are the
students that won.
There were places
in Boston that have
six times the normal
radiation background,
simply because they're made
out of marble or granite.
These include things
like the state house
and some fancy
fountains around town.
Did not know about
the fountains,
but they just thought, let's
find giant chunks of stone,
and they were right.
SARAH HANSEN: The
hands-on experiences
that Mike creates for
students of his course
are pretty unique.
He told me that when
he took this course
as an undergraduate
student at MIT,
it wasn't typically hands-on.
So I wanted to know
what it's like to teach
in a way that's so different
from his own personal
experience.
What does it take to create such
fascinating labs and lessons
without a clear model from one's
own educational background?
MIKE SHORT: It's natural.
I teach the way that I
learn, because I thought back
on all my experiences and I
thought, from which courses
did I really remember a lot?
And these were things like
hands-on blacksmithing
or laboratory courses.
We did have a lab class where
we counted a lot of radiation,
and I remember those
labs very well.
And I think back to my
neutronics problem sets.
I remember the theory
OK, but I don't
remember very many visual
instances of that class.
It just kind of happened.
The knowledge is maybe
in there somewhere.
I don't know.
But I know where
I was when I did
most of the hands-on exercises.
And in the end, you can
make anything hands-on, even
neutronics that I mentioned.
So I at some point
went skulking around
places I oughtn't, like
around in the reactor
once I got access, and found
an eight-foot pile of graphite
that was behind a
bunch of equipment.
It wasn't hidden.
It was just covered with junk.
And I asked, what's that?
They just said, oh, that's our
subcritical graphite reactor
pile.
We're going to get
rid of that next year.
So I sounded the alarm and
said, you cannot get rid of this
graphite pile.
And then our neutronics
professors Ben Forget and Kord
Smith said, yeah, you're right.
We can't.
So they spent a whole
winter restoring it
with a couple of students.
And now, it's one of the
central labs in my class
and in their class.
So we've taken the most
theory-heavy, dry, and boring
class and turned it
experimental because you can.
You're always studying
the natural world, right?
All we study at MIT is the
natural world and things
we make out of it, so everything
is reducible to practice.
Everything can be real,
if you put in the effort.
SARAH HANSEN: Part of what's
so special about this class is
the dedication that
Mike and his colleagues
have to constantly improving
it through real-time student
feedback.
And I don't mean fixing
pieces to implement
for the next semester.
I'm talking about
next-day transformations
of class procedures.
To accomplish this, Mike created
the aptly titled Rants Page.
MIKE SHORT: The Rant Page is an
anonymous, simple, PHP comment
form that I wrote, where I
want students to tell me things
that they want changed.
Because I try my best to
collect in-person feedback
from the students both
one-on-one and in class.
But some students
don't feel comfortable
telling a professor, I don't
like what you're doing.
So I give them a place to do
so completely anonymously.
It ended up being
20 lines of code.
It wasn't hard.
And what I started getting
was real-time feedback about,
I can't read your writing.
So then I know to slow it down.
Or, I really wish you
wouldn't slow the class down
for this one student's
incessant questions,
so I know to limit each
student to a few questions
if it gets to be too much.
And I would address
them in class
to say, it's safe to address
this, because it's anonymous.
I have literally
no way of knowing.
But if one person wrote
it, probably a lot of you
are thinking it.
And the students responded
positively to say,
wow, it was really
nice to know that we'd
make a suggestion at
2:00 in the morning,
and then by 10:00 in the
morning, it would be addressed.
The class would
change in real time,
and they knew they had the power
to shape their own learning.
[MUSIC PLAYING]
SARAH HANSEN: With all the
buzz around this course,
we had a ton of great questions
come in from educators
and students alike.
So we picked out
some of our favorites
and posed them to Mike.
Number one, what math do I
need to understand this field?
MIKE SHORT: That's
a good question.
It depends on how deeply you
want to understand the field.
If you want to pass
my class, if you
want a get an A in my
class, you don't really
need much math beyond
single-variable calculus.
And even then,
it's not very much.
I think we use--
we have one or two lectures with
integrals and a few lectures
with differential equations,
but linear first order things
that you solve in calculus one.
SARAH HANSEN: Number two,
when you were a student,
how did you deal
with courses that
didn't seem interesting to
you, but that you had to study?
MIKE SHORT: That's
a good question.
I have a few answers to that.
So for courses that
didn't seem interesting
that I had to study, if I
knew why I had to study it,
there was at least a
practical reason to do well.
For example, for me,
it was neutronics.
Neutron transport
is one of the things
that makes nuclear
engineers what they are.
I found it to be dry
and not very real-world,
because I knew I was never
going to be a reactor designer.
But I felt I would need to
understand neutron transport
and power levels in order to be
an effective nuclear material
scientist.
Luckily, I was right.
For the classes which I just
had to take because they were
requirements, and I had no
reason to want to take them,
I got a little sneaky.
I ended up double majoring
with material science
and wrote a petition to get
out of this one medical imaging
class and replace
it with 12 others
in order to make a second major.
And that petition was approved.
So I actually did get to simply
drop a departmental requirement
by articulating why I wanted
to study something else.
Not all students realize
that they can do this,
but they can do this.
With a very good
intellectual justification,
rules can be bent or broken.
SARAH HANSEN: OK, number three.
Why can't we just send
nuclear waste to space?
MIKE SHORT: We could just
send nuclear waste to space
and get it out of our hair.
It would be expensive.
It costs a lot of money
per gram to get something
off the planet.
Someone has to
agree to pay for it.
And what worries me most is,
what if one of those missions
goes wrong?
What if you're launching a
rocket full of the world's
worst nuclear
waste, and something
goes wrong at the launch, and
then it comes back down, along
with the rocket explosion?
Then you have
contaminated the planet.
So I personally believe in
containing nuclear waste where
we can see it rather
than blasting it off
into space and
contaminating space,
unless we know where it's going,
and that nothing will go wrong.
Because a lot of
folks are worried
about the dangers
of radiation, how
we're going to deal
with nuclear waste.
And I don't fear
nuclear waste, but I've
got a healthy respect
for it in that whatever
we do with it has to have the
lowest probability of getting
out and contaminating anything.
I think it's a necessary
thing to make in order
to make nuclear power.
So if we want to make almost
unlimited carbon-free power,
we're going to make
waste in the process.
You can't fight thermodynamics.
You're always going to have some
waste of energy or something
else.
But then what you
do with it has to be
very carefully considered.
And it sounds simple
to blast it into space,
but then you have to
think, what could go wrong,
and who could I hurt
if it goes wrong?
SARAH HANSEN:
Number four, what do
you think about the
cultural and political idea
against nuclear power?
MIKE SHORT: To me, the current
cultural and political idea
against nuclear power
is not grounded in fact.
It's grounded in emotion.
And I've talked
with a lot of folks
who either know very
little or very much
about the physics and
engineering of nuclear power.
But I find more
often than not, it's
an issue designed
to rally a base.
Strangely, I've never
really understood this.
So many environmentalists
are against nuclear power.
And I'm an
environmentalist, too,
which is why I'm
for nuclear power.
So I find the
anti-nuclear sentiment
to be so strongly democratic
and the pro-nuclear sentiment
to be so strongly
Republican, neither of which
is for reasons which
I'm willing to accept.
They seem to be more about
political tribalism than fact.
And it's interesting now that
for the first time since we've
had Chernobyl
disasters and such,
more and more environmentalists
are coming out
in favor of nuclear
power, not because they're
in favor of radiation,
and waste, and such.
But the goal is to
prevent climate change.
I would much sooner
take a risk of something
going wrong with nuclear
power than definitely lose
the battle to climate change.
Everything to me comes out to
minimizing risk to human life
and maximizing quality of life.
So to me, the risk
of nuclear power
is that if we can go all
carbon-free for energy,
we can reverse climate change.
If we're afraid of using
nuclear power for fear
of the waste getting out,
or the risk, or the weapons,
then we're automatically
losing the war,
and we're going to have an
uninhabitable planet anyway.
And we can't get
off this planet yet,
and then we'll go make
the same mistakes there
as we would here.
For example, I came into
this department wanting
to study fusion, felt it
wasn't ready yet, so I spent
a lot of my time on
fission, thinking,
this is going to be
the bridge to fusion.
Because fusion promises
more carbon-free power
with far less radioactive
waste, but not none.
And I'm willing to accept
the some, so as not
to lose the climate change
battle, which is already
on our doorstep.
I do worry that many
environmentalists
lose sight of the real goal,
which is protecting the planet.
And to me, protecting the
planet doesn't mean, do no harm.
It means, do as little harm
as possible while preserving
our quality of life.
SARAH HANSEN: Number five, while
learning, occasionally, you
will have these moments where
all of the sudden, the dots
suddenly connect, and a
previously challenging topic
becomes seemingly
perfectly clear to you.
Could you share with us
one of your brain blasts?
MIKE SHORT: Let's see.
For me, it's the same one
that most students get
at about the one-month
mark in my class,
and that's energy is matter,
that E equals mc squared.
You see it on
shirts all over MIT.
It's probably the one equation
that everyone in America knows,
but not a lot of people
really understand
that the conversion
of matter into energy
through ionizing radiation
is the movement of energy
from one form to another.
Matter is a form of energy.
And once that
clicked, everything
seemed to make
sense-- radioactive
decay, nuclear reactions,
all these things.
I remember that aha
moment in this class
that I teach as a second-year
student back in 2002.
And it's those kind
of moments that
made me want to stay in it,
because I feel like, wow, I
really know this field now.
[MUSIC PLAYING]
SARAH HANSEN: If you're
interested in learning more
about ionizing radiation,
we've got all of Mike's course
materials on our site.
You can find us at ocw.mit.edu.
You can also read more of
his instructor insights
on his OCW course page made
especially for educators.
You can find all sorts of
different instructor insights
on our educator portal
at ocw.mit.edu/educator.
Until next time, I'm Sarah
Hansen from MIT OpenCourseWare.
