Speaker 1: Yeah, welcome to Stuff from the Science Lab from how
Speaker 1: stuff works dot com. Hey guys, and welcome to the podcast.
Speaker 1: This is also Adamo, the science editor how stuff works
Speaker 1: dot com. And this is Robert Lamb, science writer at
Speaker 1: how stuff works dot com. And today we're gonna talk
Speaker 1: about a couple of experiments that have props changed the world. Yeah,
Speaker 1: these are pretty pretty big ones. Yeah, so worldwide, billions
Speaker 1: and billions of dollars or earmarked for scientific research and development.
Speaker 1: I looked this up. Turns out in two thousand nine,
Speaker 1: the United States government allowed a hundred and fourteen billion
Speaker 1: just for research and development awarded to its agencies. So
Speaker 1: the various government agencies, as you can imagine. I think
Speaker 1: that the dude in the Riddler costume on those infomercials
Speaker 1: told me this. Yeah, a lot of that money went
Speaker 1: to the Department of Defense. As you met, it always
Speaker 1: helps if you can kill somebody with your science experiment,
Speaker 1: no doubt. And then little less than half of that
Speaker 1: was split between basic research, so they're kind that's driven
Speaker 1: by scientific curiosity or interest in a particular scientific question,
Speaker 1: and then applied research, the kind of research the designed
Speaker 1: to solve practical problems, right, yeah, like some of some
Speaker 1: of the stuff that goes on, it's just really cool. Like, um,
Speaker 1: I was doing a news article several months back about
Speaker 1: research into how hammerhead sharks seek and yes, government was
Speaker 1: flipping the bill for a lot of that, and I
Speaker 1: have yet to come up with a way that that
Speaker 1: could be used to kill somebody or really do anything
Speaker 1: other than understand hammer heads. Right, So I was bringing
Speaker 1: up those numbers just to illustrate how many experiments are
Speaker 1: going on right now, a lot of which we will
Speaker 1: never ever know about, a lot of which won't get
Speaker 1: picked up in the New England Journal of Medicine. So
Speaker 1: we decided to highlight a few that particularly stand up.
Speaker 1: So we're doing a series, the two part series, in
Speaker 1: which we highlight a couple of our favorite experiments with
Speaker 1: the big guns. Here we're talking, yeah, our first one's Darwin. Yeah,
Speaker 1: and I should mention in a few instances we're gonna
Speaker 1: talk about too closely related experiment. It's as opposed to
Speaker 1: one single experiment, just because, as you guys know, science
Speaker 1: stands on the shoulder of giants, so it's hard to
Speaker 1: sometimes separate out who did what when, and sometimes it's
Speaker 1: like a short person standing on the shoulder of a giant,
Speaker 1: and then there's another giant standing on top of the
Speaker 1: short person. But if you get the short person out
Speaker 1: of the mix, then it all falls apart. It's like singer,
Speaker 1: that's true feet Yeah, except Jinga with giants. Yeah. Right,
Speaker 1: So who's the first nominee? Charles Darwin? All right, let's
Speaker 1: talk about Darwin. Darwin's flowers. Um, don't you mean Darwin's
Speaker 1: Galapagos Islands trip. Um, No, you don't mean flowers. No,
Speaker 1: that was this is kind of this kind of came
Speaker 1: later because the Galapagos Island's trip is famous because you know,
Speaker 1: he was always looking at birds and and he you know,
Speaker 1: really putting together you know, all the the the data
Speaker 1: that would lead to origin of species and uh but
Speaker 1: but after all that, you know, it's like the theories
Speaker 1: out there and it's you know, not popular with everybody.
Speaker 1: It's still needs a lot of support, and he has
Speaker 1: his supporters, but there's also plenty of people just like
Speaker 1: making fun of him and drawing and really mean cartoons. Yeah,
Speaker 1: he was and he was of a divisive character for sure,
Speaker 1: and he didn't want to be actually, no, he hated it.
Speaker 1: We we have a I think a really good article
Speaker 1: on the man I wrote that one um. But he
Speaker 1: was having to he was he retreated from the public
Speaker 1: cup eye and let other people handle the pr stuff,
Speaker 1: and he went back to experiments. See what did he
Speaker 1: do well? He started looking into um orchids and uh
Speaker 1: and their pollinators. So he's looking to reinforce the theory
Speaker 1: of natural selection, right, because this boils down to um.
Speaker 1: You know, you look at at some of the crazy
Speaker 1: like orchids and flowers out there and and they'll be
Speaker 1: just be some there's such a variety of design um
Speaker 1: in them. And then somewhere out there in the world
Speaker 1: there's a there's an insect that's that's it's custom evolved
Speaker 1: to pollinate that one particular flower. Right. That was his thought, Yeah,
Speaker 1: that was that was his thoughts. So he started, like,
Speaker 1: you know, if he were round the day, he'd make
Speaker 1: a spreadsheet of this, you know, like which which flowers
Speaker 1: line up with which pollinators? Right, take the Star of
Speaker 1: Bethlehem orchid for example. Um it's an orchid that stores
Speaker 1: nectar near the bottom of a tube up to twelve
Speaker 1: inches long. So Darwin saw this design and he predicted
Speaker 1: that there was a matching animal outfit somewhere out there
Speaker 1: in the where there's there's one insect that's made to
Speaker 1: take care of this. So sure enough, in three scientists
Speaker 1: discovered that the hawk moth sported along probiscus or knows,
Speaker 1: essentially uniquely suited to reach the bottom of this particular
Speaker 1: orchids nectar tube. So this was good because again it
Speaker 1: was providing evidence for his theory of natural selection. Um,
Speaker 1: you know, it's giving credence to on the origin of
Speaker 1: species and just generally bolstering the modern framework of evolution
Speaker 1: as we know it with flowers. Yeah, so let's do
Speaker 1: another biology one. Let's talk about DNA. Oh yeah, this
Speaker 1: is a big one as well. Watson and right, Yeah, well,
Speaker 1: Watson and critic and all the headlines and lots of
Speaker 1: school kids. Certainly no James Watson and Francis Crick as
Speaker 1: the guys who unlocked the mystery of DNA but there
Speaker 1: are a whole lot of other players involved in the mix.
Speaker 1: So that nineteen sixty two Nobel Prize in Medicine was
Speaker 1: split among Watson, Creek, and Maurice Hugh Wilkins. These are
Speaker 1: the guys who figured out the molecular structure of DNA,
Speaker 1: along with the help of more than a few scientists
Speaker 1: like Hershei and Chase. Right, so, back in nineteen fifty two,
Speaker 1: Elfin Hershei and Martha Chase were conducting this now famous
Speaker 1: blender experiment that identified DNA as a molecule responsible for heredity,
Speaker 1: no small feet, and Hershiean. Chase's research prompted a bunch
Speaker 1: of scientists to decipher DNA's molecular structure. Like it was
Speaker 1: just like the scientific sort of gold rush. Instead of
Speaker 1: focusing on goal, they were focusing on doxy ribonucleic acid.
Speaker 1: I like to think that each duo of scientists was
Speaker 1: like like a cop duo, where one was the good
Speaker 1: cop when it was a bad cop, so like Watson
Speaker 1: a crick or like like once taking the strong arm
Speaker 1: with the DNA and the other just like bringing up coffee.
Speaker 1: Did you ever see the TV movie about this, The
Speaker 1: Race for the Double Helix a k A Life Story?
Speaker 1: I think it. It was a BBC production and I'm
Speaker 1: surprised you have not seen it because Jeff Goldbloom was
Speaker 1: in it. WHOA really? Oh man, I bet he's He's
Speaker 1: awesome and a little crazy in it. Yeah, I forget
Speaker 1: which one he was, Watson or Creek, but I must
Speaker 1: have seen that back in the day, because whenever I
Speaker 1: think of DNA and stuff, I always think of gold
Speaker 1: Bloom and I can never think why, And now I
Speaker 1: know it was. Are you sure you weren't thinking about
Speaker 1: the fly where? Because there's a lot of DNA stuff
Speaker 1: in there right right, The fly and the race for
Speaker 1: the double helix. That's the movie. I based my understanding
Speaker 1: of DNA on. So Prize winner Wilkins, along with this
Speaker 1: colleague Rosalind Franklin, who did not win the DNA Nobel Prize,
Speaker 1: which is a whole separate but interesting story, use this
Speaker 1: technique called X ray to fraction to study DNA. And
Speaker 1: we're going to talk about this technique a little later
Speaker 1: on too with you Robert. Right, So, the technique basically
Speaker 1: involves shooting X rays at in this case a line
Speaker 1: fibers have purified DNA. Yeah. The idea is when X
Speaker 1: rays travel through something, they're going to get defracted and
Speaker 1: come theither side. But they get diffracted, they get moved
Speaker 1: around and alter, and there's't they can tell you what
Speaker 1: it just passed through. It's kind of like when you
Speaker 1: and in a very there's a very broad example, but
Speaker 1: it's like when you get an X ray made of
Speaker 1: your tooth, the you know, at the dentist office. Um,
Speaker 1: we're in a back alley, you know. But the the
Speaker 1: X rays passed through your teeth and and onto that
Speaker 1: little film, right, so, and and then they give your
Speaker 1: information about about what happened, Yeah, between cavities exactly. Yeah.
Speaker 1: So yeah, in this case, the diffracted X rays form
Speaker 1: a pattern that's unique to the molecul in question, and
Speaker 1: in this case it was d N A and so
Speaker 1: Rosalind Franklin's now famous photo of DNA shows this X
Speaker 1: shaped pattern. Of course, you have to know how to
Speaker 1: interpret that pattern to quote unquote see the molecule, and
Speaker 1: Watson and Crick did so. Watson and kriicknew that the
Speaker 1: photo represented the signature of a helical molecule, and they
Speaker 1: also figured out the width of the helicks by analyzing
Speaker 1: Franklin's image, and DNA was somewhat decoded. Yeah. The rest
Speaker 1: is history, and we have the image of the double
Speaker 1: helix everywhere, and we fully understand everything that DNA can
Speaker 1: do now, right, Yeah, yeah, we got it, We got
Speaker 1: it down. So let's look at another world changing biology
Speaker 1: type experiment that we like. Oh yeah, yeah, this one,
Speaker 1: this one was really cool. And this one has to
Speaker 1: do with vaccinations, um and the eradication of smallpox. Right, so,
Speaker 1: until recently, smallpox is a pretty serious public health problem,
Speaker 1: all right. So then this said, there was this British
Speaker 1: chef physician by the name of Edward Jenner, and uh
Speaker 1: round he started, uh noticing that dairy maids would catch
Speaker 1: something called cow pox. What is Jenner doing noticing the
Speaker 1: dairy maids is one question? Well, probably pretty cute. Yeah,
Speaker 1: they're pretty cute, cute gals, and and they were they
Speaker 1: were catching some sort of pox from this this cow
Speaker 1: pox from the cows and uh and you know they
Speaker 1: suffered through that. But then after they've had cow pox,
Speaker 1: they're immune to smallpox. Really. Yeah, So he started studying
Speaker 1: this phenomenon, hanging out with more and more dairy maids.
Speaker 1: You know, cow pox is still around, so it's beaver pox.
Speaker 1: I've not heard of beaver I just made that one up.
Speaker 1: I'm kidding, there's no beaver pox. So eventually Jenner decided
Speaker 1: to see if he could um, if he could transfer
Speaker 1: immunity to smallpox by infecting someone with cow pox on purpose.
Speaker 1: So he found, uh, this little boy by the name
Speaker 1: of James Phipps. Okay, what did James Phipps parents make
Speaker 1: of this? By the way, those are kind of good
Speaker 1: old days of human experimentation. Yeah, because I mean it
Speaker 1: gets kind of ground because the way he decided to
Speaker 1: to to essentially vaccinate him that we didn't really know
Speaker 1: it was gonna work, you know, it was still an
Speaker 1: experimental phase. Was he made cuts on the boy's arms
Speaker 1: and then inserted some fluid from the cow pox source
Speaker 1: of a local dairymaid that he was hanging out with
Speaker 1: named Sarah Sarah Elms. And so the kid uh contracted
Speaker 1: cow pox and then recovered and was then immune to smallpox. Right, So,
Speaker 1: forty eight days later, Jenner said, okay, you had your
Speaker 1: cow pox cuts, let's see what you're going to do
Speaker 1: a smallpox And sure enough he exposed him and he
Speaker 1: found out that the boy was immune, proving gender's theory correct.
Speaker 1: Fast forward, uh a little while, and uh there's no
Speaker 1: more you know, and then you have a powerful small
Speaker 1: pox vaccine going on. So pretty cool. So let's talk
Speaker 1: a little chemistry. Although the scientists at the center of
Speaker 1: our next experiment. Considered himself a physicist, not a chemist.
Speaker 1: He was the man who once said, have you heard
Speaker 1: this quote? All science is either physics or stamp collecting,
Speaker 1: and he was talking about the scientific method. I assume
Speaker 1: I had not heard that quote. So the man in
Speaker 1: question is Ernest Rutherford, and he's a pretty amazing guy.
Speaker 1: He's born in New Zealand. He's one of twelve children.
Speaker 1: That's a large, large New Zealand family, or any family.
Speaker 1: He's the guy who came up with listen to this.
Speaker 1: He's a guy who came up with the principles of alpha,
Speaker 1: beta and gamme rays, the proton, the newtron, half lift,
Speaker 1: and daughter Adams. One guy came up with all that.
Speaker 1: Quite a role. Yeah, I've heard him called the father
Speaker 1: of nuclear physics, and that's seems appropriate enough. And future
Speaker 1: biggie's like Neils Bore Oppenheimer and James Chadwick, I'll looked
Speaker 1: to him for guidance. But we're going to talk about
Speaker 1: one of his adventures with the atomic nucleus and revealing
Speaker 1: the structure of the atom. So let's talk about the
Speaker 1: what Rutherford was doing. Basically, he's carrying off a kind
Speaker 1: of a simple experiment, and uh and one that you
Speaker 1: can you can you can reproduce at home. All you
Speaker 1: need is what a You need an alpha ray emitter
Speaker 1: or some sort of like alpha ray gun. Right, You
Speaker 1: need some gold foil. Yeah, and you need a scentilator.
Speaker 1: What's that, Well, scentilator is essentially back in the day,
Speaker 1: it was a screen coated with stink soul fund and
Speaker 1: it helps you to figure out where the particles were
Speaker 1: going after you fired them, after after you fired them. Okay,
Speaker 1: well that maybe a little hard to get a hold off,
Speaker 1: but still these are the main elements of the experiment.
Speaker 1: So let's talk about the experiment. It was also called
Speaker 1: the Geiger Marsden experiment, named after a Hans Geiger gold
Speaker 1: foil experiment though sounds. So here's what they did. They
Speaker 1: got a source of radioactive particles, like Robert was just
Speaker 1: leading to. They fired them through these really thin foils
Speaker 1: like gold, and by thin we mean one or two
Speaker 1: atoms thick, super super super thin, and they encircled their
Speaker 1: whole set up with aforementioned detecting screen, the scintillator, the
Speaker 1: screen that was gonna tell them where the particles were going.
Speaker 1: After they fired them. So what Rutherford and Cove figured
Speaker 1: out was that most of the radioactive particles were actually
Speaker 1: firing straight through the foil. Okay, that makes sense. And
Speaker 1: then a few of the particles were being deflected at
Speaker 1: at a smaller angle, and then a very tiny portion
Speaker 1: of the particles were being reflected back at a large angle.
Speaker 1: And like we were saying earlier, the deflection tell us
Speaker 1: that there's something going on inside the material that they're
Speaker 1: that they're passing through. Right. So Rutherford, Geiger, and Marsden
Speaker 1: took that to me and that there was a lot
Speaker 1: of quote unquote empty space and atoms allowing all those
Speaker 1: radioactive particles to pass straight through to the particle screen
Speaker 1: or to the the scintillator. But it was the sharp
Speaker 1: deflections that intrigued them the most. And so their conclusion
Speaker 1: was that there was a strong positive charge at the
Speaker 1: heart of the gold atoms that was deflecting those particles
Speaker 1: almost straight back toward the source. And he called this
Speaker 1: strong positive source that was doing the deflection the nucleus,
Speaker 1: And he said the nucleus must be small compared to
Speaker 1: the atoms overall size, otherwise more you would have had
Speaker 1: more particles bouncing back right. So yeah, so he basically
Speaker 1: met the inside of the atom. So today we still
Speaker 1: visualized atom as Rutherford did, a small positively charged nucleus
Speaker 1: surrounded by a vast firstly populated region with a couple
Speaker 1: of electrons. Wow, so you can you can really tell
Speaker 1: a lot about something by firing some radiation through it.
Speaker 1: It's such a simple experiment, but it's so brilliant. It
Speaker 1: is brilliant. Right. So we mentioned X ray diffraction a
Speaker 1: little bit earlier. When we're talking about DNA, we're talking
Speaker 1: about Rosalind Franklin and her X ray defraction studies. But
Speaker 1: as we pointed out, her work wrote a lot to
Speaker 1: Dorothy Krowfet Hodgkin. She was one of only three women
Speaker 1: ever to win the Nobel Prize in chemistry, and Hodgkin
Speaker 1: was pretty darn good at X ray diffraction, so it's
Speaker 1: not really surprising that she eventually revealed the structure of
Speaker 1: pretty much one of medicine's most important chemicals, penicillin. Indeed,
Speaker 1: so back in Alexander Fleming had discovered the bacteria killing substance,
Speaker 1: but scientists had a really hard time purifying the chemical
Speaker 1: in order to develop an effective treatment. So what Hodgkin
Speaker 1: did was she mapped out the three D arrangement of
Speaker 1: penicillin's atoms, and essentially she opened all these new avenues
Speaker 1: for creating and developing semisynthetic derivatives of penicillin. Yeah, it's
Speaker 1: like when hackers like break the code for something like
Speaker 1: DVD encryption, you know, so that they can rip it.
Speaker 1: It's like like, here was something that was really important
Speaker 1: to his penicillin, and in in fact she allowed us
Speaker 1: to crack it do more with it, right, but telling
Speaker 1: us all that stuff about the molecular structures she helped
Speaker 1: out a lot. And in this case what she did
Speaker 1: was after two different companies center penicillin crystals, Hodgkin pass
Speaker 1: those X ray waves through the crystals and allowed the
Speaker 1: radiation to strike this photographic plate. We did cover this
Speaker 1: a little bit before, so as the X rays interacted
Speaker 1: with the electrons in those sample there to fracked and
Speaker 1: reveals the interstructure excellent. And then she went on to
Speaker 1: deal with other structures, right, like vitamin B twelve she did,
Speaker 1: she did, and yeah, penicillin was indeed the big one,
Speaker 1: and of course she she won the Nobel PRIs in
Speaker 1: Chemistry unshared in which is a big deal. Usually they're
Speaker 1: scientists selfish. I don't know about that. So wow, those
Speaker 1: are those are some world changing experiments right there. I
Speaker 1: feel a little change just talking of Um, I feel inspired. Yeah,
Speaker 1: I hope there are some world changing experiments going on
Speaker 1: right now. I'm gonna fire some radiation through some stuff
Speaker 1: just to see what's going on. We need to get
Speaker 1: back to your desk. Yeah, yeah, what's going on in
Speaker 1: that cup of coffee. Well, the thing is, if you're
Speaker 1: inspired by our world changing experiments, be sure to listen
Speaker 1: to part two because we've got more of these coming up.
Speaker 1: And um, and there's gonna be the last radiation passing
Speaker 1: through things in that one. So if you want is
Speaker 1: endo that in this this podcast, then there's gonna be
Speaker 1: less next time. Yeah, we're going to get into some
Speaker 1: cool stuff like determining the speed of light. Yeah, primordial
Speaker 1: suite dogs, all sorts of good stuff. Right. So, if
Speaker 1: you want to go to the home page and look
Speaker 1: up some cool experiments in the meantime, just type in
Speaker 1: science experiments and you'll get ten science experiments to change
Speaker 1: the world. Also, check out our blog where we update
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