Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff.
Speaker 1: I am your host executive producer, John than Strick, London.
Speaker 1: I love all things tech. It is time for another
Speaker 1: classic episode of tech Stuff, and today we're going to
Speaker 1: visit an episode that we originally published on January two
Speaker 1: thousand twelve. Chris Pallette my co host at the time,
Speaker 1: and I decided to look into the topic of radio telescopes.
Speaker 1: I talked about these not too long ago when I
Speaker 1: did a series about DARPA. Well, now we're gonna have
Speaker 1: a full episode dedicated to the topic, and I hope
Speaker 1: you guys enjoy. So. Um, before we get started, we're
Speaker 1: gonna do something we haven't done a little while. Yeah,
Speaker 1: we're gonna listen to a little listener mail. This listener
Speaker 1: mail comes from me who says I love your podcast
Speaker 1: and have enjoyed listening to your incifle and quirky explanations immensely.
Speaker 1: I tried to search through the past podcast to see
Speaker 1: if you have done one on radio telescopes, to no avail,
Speaker 1: So I hope I didn't just miss it. It seems
Speaker 1: to me that radio telescopes are being used frequently to
Speaker 1: learn about this and study the far reaches of the
Speaker 1: galaxy and beyond. And that's pretty darn cool, so it'd
Speaker 1: be neat to learn more about how they work. Thanks
Speaker 1: and thanks for the show, Minka. Well you're welcome, Inga.
Speaker 1: I just wanted to say you're welcome. All right, So
Speaker 1: now we're moving on to our topic, the Smurfs. No, no,
Speaker 1: we're gonna talk about radio telescopes. Good, yeah, we sort of. Well,
Speaker 1: we've talked about things that relate to radio telescopes like
Speaker 1: radio and stead yes, and steady set, which does very
Speaker 1: much relate to radio telescopes. Well, what do radio telescopes do?
Speaker 1: Why are they important? Well, it's funny that you should
Speaker 1: mention that, Yeah, because they're I my notes crashed, so
Speaker 1: I don't know what I'm talking about. Your notes crash. No,
Speaker 1: I'm not. I'm just kidding. They're still up. He can't
Speaker 1: see my computer from where he sits. Yes, because he's
Speaker 1: sitting directly across from me. Yes. See. If if you
Speaker 1: ever wondered if that was true or not, it is. Yeah,
Speaker 1: um no, it's it's actually using it's unlike a typical
Speaker 1: visual telescope, which uses lenses and your eyeball, and you
Speaker 1: look through it and you look for stuff on the
Speaker 1: other side and base it directs light which is in
Speaker 1: the visible spectrum of the electromagnetic frequency. Yes, to our
Speaker 1: to our eyeballs ultimately right right, But and again another
Speaker 1: drastic oversimplification of the parts. But a radio telescope is
Speaker 1: actually monitoring different parts of the electromagnetic frequency. Yeah. Yeah,
Speaker 1: it's good looking at a completely different spectrum. So this
Speaker 1: is part of the spectrum that is not visible to
Speaker 1: the naked eye. So we are using these telescopes to
Speaker 1: measure um radio frequency variations that come from outer space.
Speaker 1: And it turns out that lots of stuff out there
Speaker 1: generates radio frequencies, right, So things like quasars, pulsars, galaxies, uh,
Speaker 1: distant stars, these sort of things can generate electro magnetic
Speaker 1: radiation and in the form of radio frequencies. And sometimes
Speaker 1: these are are objects that we can't detect visually, but
Speaker 1: we can detect them if we have a sensitive enough
Speaker 1: tool that can can detect and measure radio frequencies. So
Speaker 1: that's really what a radio telescope is all about. And
Speaker 1: it's kind of tricky picking up radio frequencies from outer
Speaker 1: space because only certain the actual band of frequencies or
Speaker 1: wavelengths I should say, the band of wavelengths that exist
Speaker 1: within the electromatic spect magnetic spectrum that are radio frequency waves.
Speaker 1: It's pretty broad. Yeah, about ten meters and to one millimeter.
Speaker 1: That's a pretty good size. Yeah, you can actually get
Speaker 1: radio waves that are even longer than that, like the
Speaker 1: size of football fields. But here's the thing is that
Speaker 1: the Earth has a level of the atmosphere called the ionosphere. Now,
Speaker 1: the iono sphere is uh, it's kind of funky. So
Speaker 1: you guys probably have heard us talk about ions before,
Speaker 1: you know. That's when we're talking about uh, atoms that
Speaker 1: have either gained or lost an electron. And if you
Speaker 1: ionize something, that means you've got some free electrons roaming
Speaker 1: around in it. So like an ionized gas or a
Speaker 1: plasma can actually hold carry an electric charge. Right, Yes,
Speaker 1: Why are you smiling at me just because I saw
Speaker 1: a whole bunch of people going WHOA free electrons? Yeah? Sorr,
Speaker 1: there're so expensive. Otherwise that's true. Have you seen my
Speaker 1: electric bill? Anyway? So you have the ionosphere, whether these
Speaker 1: free roaming electrons out there, and uh, and it kind
Speaker 1: of acts as a bit of a shield or reflector
Speaker 1: in in some ways, and so radio waves of a
Speaker 1: certain way wave length cannot pass through the ionosphere. Essentially,
Speaker 1: anything that's ten meters are longer, the ionosphere is opaque
Speaker 1: to those. That's why you can actually broadcast certain long
Speaker 1: wavelength radio waves uh and bank them off the ionosphere
Speaker 1: because it won't pass through. Now, when you start getting
Speaker 1: shorter than a ten meter wave length, you have radio
Speaker 1: waves that can pass through the ionosphere. But if it's
Speaker 1: longer than twenty centimeters, which is about one point five
Speaker 1: gig hurts in frequency when you talk about these, If
Speaker 1: it's longer than twenty centimeters, you start to have distortion
Speaker 1: as it passes through the ionosphere. It's called scintillation. And
Speaker 1: this isn't that different from the way when we look
Speaker 1: up into the sky and we see stars twinkling. That's
Speaker 1: sort of the same sort of thing we talked about
Speaker 1: being scintillating, same kind of idea, except in this case,
Speaker 1: you know, that's we're talking about the visual spectrum there,
Speaker 1: but here, Yeah, the twenty centimeters are longer, you run
Speaker 1: into that problem. And so that's not entirely useful for
Speaker 1: measurement purposes. So radio telescopes tend to focus on pun
Speaker 1: intended Uh, wavelengths that are between one centimeter and twenty
Speaker 1: centimeters in length tend to Now there are some variations.
Speaker 1: And also if you were to have a radio telescope,
Speaker 1: say in orbit where it's you know, you don't have
Speaker 1: the ionosphere as a in play. Um, that's a different story.
Speaker 1: But ground based radio telescopes kind of had to play
Speaker 1: within these rules because the way the ionosphere works. One
Speaker 1: of the nice things though about the radio telescope is that, uh,
Speaker 1: those frequencies generally come through pretty clearly. So uh, putting
Speaker 1: one of the ground based radio telescopes in orbit really
Speaker 1: wouldn't improve its ability to detect signals um, at least
Speaker 1: based on my research, and not not within anything that's
Speaker 1: within those wavelengths. Yeah. Actually it's it's a little tricky
Speaker 1: to detect that stuff anyway, because we're talking about really
Speaker 1: we signals. I mean, by the time they reached the Earth,
Speaker 1: that these signals are not very strong at all. In fact,
Speaker 1: one one reference I I looked at said that that
Speaker 1: if you were to add up all the energy that
Speaker 1: every radio telescope on Earth had been subjected to since
Speaker 1: they were built, it still would not equal the energy
Speaker 1: would find in the snowflake. Yeah, that's pretty impressive. Act
Speaker 1: grant that snowflake is the size of Detroit. No, I'm kidding,
Speaker 1: I'm kidding. Typical snowflake. No. Uh. And it is also
Speaker 1: worthwhile to note, especially before anyone writes in um, that
Speaker 1: radio telescopes do have to be placed away from population
Speaker 1: centers in general, uh, to some degree to because there
Speaker 1: is earthly interference. Yeah, there's terrestrial radio interference that you
Speaker 1: have to try and minimize as much as possible. Otherwise
Speaker 1: it's just so much noise that you're not going to
Speaker 1: even find any signal out there, right right, So, um, Yeah,
Speaker 1: it has its it has its good points and in
Speaker 1: its ad points because of the frequencies, it's able to monitor.
Speaker 1: And it's a good point too that you uh, you
Speaker 1: mentioned the from the very first because these these devices,
Speaker 1: I mean, I'm I imagine people you know, have a
Speaker 1: good idea what radio telescopes look like. I mean, we've
Speaker 1: all seen satellite dishes, and to some degree that's more
Speaker 1: or less what they look like. In fact, you may
Speaker 1: have seen pictures of them, but um that I think
Speaker 1: gives it the the sort of feeling that it's a
Speaker 1: fairly recent thing. And in fact, um it was somebody
Speaker 1: in uh nine thirty three who who figured out that, um,
Speaker 1: there was, uh, there were radio frequencies coming from extraterrestrial bodies.
Speaker 1: Someone at of course Bell telephone laboratories, laboratories. You always
Speaker 1: do that. I can't fight it, that I can't fight
Speaker 1: this feeling anymore. I can't. But yes, so you're talking
Speaker 1: about Carl Carl Jansky. Carl Jansky, Yes, Uh, he he
Speaker 1: built the first antenna that could be used as a
Speaker 1: radio telescope back in ninety one, but it would take
Speaker 1: a couple of years to really figure out, uh, the
Speaker 1: fact that you could use this to to explore the
Speaker 1: heavens above. Because when he built his radio frequency detector,
Speaker 1: it was not to act as a radio telescope. It
Speaker 1: was meant to detect static that could potentially interfere with
Speaker 1: radio telephone services. Right, So he was he was working
Speaker 1: literally on a project for Bell. Yeah, and what happened
Speaker 1: was he discovered that there was this interesting hissing noise
Speaker 1: he was picking up, and that was hitting a cycle.
Speaker 1: The hissing noise would would occur at a certain time
Speaker 1: every day, and the cycle hit, well, not every day,
Speaker 1: the cycle hit every twenty three hours and fifty six minutes,
Speaker 1: And once he removed the snake from the line, he
Speaker 1: realized there was something else hit. He figured out that
Speaker 1: the twenty three hours of fifty six minutes was essentially
Speaker 1: the period that it takes for if you've if you've
Speaker 1: got a fixed point on the sky for the you
Speaker 1: to come background so that you're pointing at that same
Speaker 1: object and come up again later. Eventually he determined that
Speaker 1: this was the the origin of this radio frequency was otherworldly,
Speaker 1: so it was coming from outside the Earth, and that
Speaker 1: it was in fact coming from somewhere in the Sagittarius
Speaker 1: constellation far out. Yeah, so guys, I'm picking up a
Speaker 1: signal from outer space. No, I'm sorry, it's not from
Speaker 1: outer space. It's just from just outside the room. It's Tari,
Speaker 1: She's telling me that we need to take a break
Speaker 1: to thank our sponsor. So it would take a few
Speaker 1: more years before you saw anyone build a parabolic antenna,
Speaker 1: which is what Chris was talking about earlier, the dish
Speaker 1: style antenna. Those are not the only kind of antennas
Speaker 1: that are used in radio telescopes. It's probably, i would argue,
Speaker 1: probably the most iconic and the most common that we
Speaker 1: we see. But there are other types of antenna as,
Speaker 1: including dipole antenna's, cylindrical parabolics, which are they kind of
Speaker 1: look like a trough. Uh there are the yaggy antenna's,
Speaker 1: which are um not little guys who teach you how
Speaker 1: to use kung fu kara, I should say, their horn
Speaker 1: antennas their mills crosses that kind of STU mills crosses
Speaker 1: telescope um. Various ways of doing this, but the principle
Speaker 1: is essentially the same. It's to try and gather to
Speaker 1: detect together as much as radio frequency UM radiation as possible.
Speaker 1: And usually there are several reflectors involved that reflect radio
Speaker 1: frequencies to a focal point that can then send the
Speaker 1: signal to receiver and then from there it gets amplified.
Speaker 1: And we'll go through that process in a little bit.
Speaker 1: But uh so in and the parabolic style of of antenna,
Speaker 1: this is why you have that big dish. The dish
Speaker 1: part is actually reflecting frequencies so that they all are
Speaker 1: directed to a single focal point and that's usually called
Speaker 1: the feed. That's usually a small antenna called the feed
Speaker 1: that uh as often called the feed horn, that will
Speaker 1: collect the signal and send it to the receiver. Yes,
Speaker 1: so these these radio frequencies are, like we said, generated
Speaker 1: by lots of different stuff out there in the in
Speaker 1: the in space. Um so. But the problem is that
Speaker 1: the they're so so delicate. There's so such tiny little
Speaker 1: frequencies that you have to really control for the noise element,
Speaker 1: not just by trying to isolate the antenna of it,
Speaker 1: but also by making sure the material you've used in
Speaker 1: your antenna array is the right kind of stuff, because
Speaker 1: they're pretty sense of things, and also the amount of
Speaker 1: information you can get is very much connected to the
Speaker 1: side of your antenna. Bigger antennas are able to provide
Speaker 1: a higher resolution image. It's kind of a weird word
Speaker 1: to say, because we're not talking about visible light necessarily,
Speaker 1: but an image of what it is you're looking at. Right. So,
Speaker 1: so the larger the better in general. But if you
Speaker 1: start building so large that the material itself is heavy
Speaker 1: enough to warp because it's it's it's so heavy that
Speaker 1: the structure itself can't maintain a specific shape, well, then
Speaker 1: you're not reflecting the radio frequencies to that focal point anymore,
Speaker 1: you've warped it out of shape. So you have to
Speaker 1: build it out of special materials and you have to
Speaker 1: plan for Okay, well, we know that by designing an
Speaker 1: antenna of this size, this particular warping is going to occur,
Speaker 1: so we have to factor that into the design so
Speaker 1: that the warping actually ends up helping rather than hurting.
Speaker 1: And usually you do that by adding a second reflector
Speaker 1: that is that's movable, so you can have a second
Speaker 1: reflector actually um position in such a way where the
Speaker 1: distortion from the main reflector hit the second reflector, which
Speaker 1: then reflects it back to the focal point. So it
Speaker 1: gets a little complicated. In fact, there are two main
Speaker 1: types of secondary reflectors. There's the Cassegrain focus, which is
Speaker 1: a reflector that's in front of the main antenna or
Speaker 1: the main reflector, i should say. And then there's another
Speaker 1: one if you have it in the back. It's called
Speaker 1: Grigoryan focus, and it chants a lot. At a feeling
Speaker 1: you were going to say that, yeah, there was a
Speaker 1: pretty good chance. Uh yeah, it's possible. Um Now, given
Speaker 1: what Johnathan was just talking about, giving the materials and
Speaker 1: and the uh, there are a lot of things that
Speaker 1: that can affect uh, the efficiency of a radio telescope,
Speaker 1: including heat, because the materials will expand or contract, wind,
Speaker 1: the surface of the material itself, the surface of the
Speaker 1: material itself. Um. But other than that, I mean, once
Speaker 1: you take all these things into account, it is theoretically
Speaker 1: possible to build as larger radio telescope as you possibly can.
Speaker 1: There's really no limit to the size other than the
Speaker 1: fact that you're going to have to take things like
Speaker 1: gravity and temperature and things like that into a tensile strength.
Speaker 1: But conceivably, if you could build one that's three times
Speaker 1: the size of Earth, it would work. Yeah. But that
Speaker 1: and that's fascinating because it's it's not it doesn't have
Speaker 1: to be a particularly large or particularly small device. It
Speaker 1: just you know, you can pick up more with it.
Speaker 1: And a lot of a lot of radio telescopes are
Speaker 1: actually telescope like antenna arrays, So it's not just one
Speaker 1: antenna's several antennas working together in order if you to
Speaker 1: gather this information work, that's what I say. And and
Speaker 1: that that helps you create a larger radio telescope just
Speaker 1: but you know, you're adding extra elements, and it means
Speaker 1: that you sort of get around part of the problem,
Speaker 1: which is, you know, building just an enormous single antenna.
Speaker 1: You can do an array of antennas. There are different
Speaker 1: limitations on this as well. Um. So, the signal that
Speaker 1: you're picking up with this radio telescope is really really weak,
Speaker 1: So in order for you to have it, uh and
Speaker 1: to to transmit first you have to you have to
Speaker 1: transfer the radio frequency information by by changing it into electricity.
Speaker 1: But because the frequency signal is so weak, the electric
Speaker 1: current would be pretty pathetic. You would not be able
Speaker 1: to measure it just by converting it right from radio
Speaker 1: frequency to electricity without amplifying it in some way. So
Speaker 1: typically a radio telescope will then have a pre amplifier.
Speaker 1: So you musicians out there and and and radio folks,
Speaker 1: you know, you're probably pretty familiar with the idea of
Speaker 1: a pre amplifier. Microphones usually have a pre amplifier that
Speaker 1: kind of thing. Um So, a pre amplifier is really
Speaker 1: just a a way of boosting a signal a certain
Speaker 1: amount before it gets truly amplified, uh for the final
Speaker 1: use of whatever that signal is gonna be, whether it's
Speaker 1: in the audio industry, or in this case, the measuring
Speaker 1: the celestial bodies. Yeah, I was gonna say that they
Speaker 1: don't necessarily usually have them anyway. Um, well, that's that's fair,
Speaker 1: but it does. It does assist, uh, and in picking
Speaker 1: up these weak signals, that's for sure. Yeah. And so
Speaker 1: the kind that tends to be used in radio telescopes
Speaker 1: are called low noise amplifiers because we're talking about such small,
Speaker 1: very very quiet signals. And so, boy, I'm glad didn't
Speaker 1: do the old listener mail beginning because then with all
Speaker 1: this it would have proably blown everybody's ears out. So
Speaker 1: the the these l n A pre amplifiers take these
Speaker 1: um signals and then they boost them. Now here's the thing.
Speaker 1: Any sort of interference at this point could really compromise
Speaker 1: the measurements you're making. So that includes molecular movement of
Speaker 1: the pre amp. So the fact that you know, everything
Speaker 1: in matter is made up of molecules, and these molecules
Speaker 1: move even in solid objects, right, yes, so they in
Speaker 1: a in big radio telescope facilities, things like the professional
Speaker 1: ones that you would find in say NASA, they tend
Speaker 1: to have to cool down the pre amplifier to reduce
Speaker 1: molecular movement as much as possible, and usually to around
Speaker 1: ten kelvin. It's pretty cold. Pretty cold, yeah, zero kelvin
Speaker 1: means no molecular movement. That's what like the deepest reaches
Speaker 1: of space would be is zero kelvin. So ten kelvin's
Speaker 1: pretty cold. They tend to use liquid helium to cool
Speaker 1: down the this this device low enough so that it
Speaker 1: reduces the chance for it to contribute noise to this signal.
Speaker 1: All right. From there, the signal moves into a mixer, yes,
Speaker 1: where it has a party and networks with people and not. Oh,
Speaker 1: should have taken different notes. Okay, well I'll just work
Speaker 1: from memory here then, um no, a mixer. The mixer's
Speaker 1: purpose is to change the frequency of the signal. Now,
Speaker 1: the signals are very high frequency and uh, and it
Speaker 1: turns out that it's easier to amplify lower frequencies. It's
Speaker 1: possible to amplify higher frequencies, but in general, it takes
Speaker 1: less uh effort to amplify the lower frequency signals. And
Speaker 1: if it's kept it it's high frequency and you're just
Speaker 1: you're you're working with the frequency at that and it's
Speaker 1: native frequency. There's the chance they'll travel back up the
Speaker 1: antenna and create feedback. It's not dissimilar to what would
Speaker 1: happen with a microphone too close to a speaker, where
Speaker 1: you get that wonderful sound. That's wonderful. Now you're you're
Speaker 1: probably more familiar with it than I am with your
Speaker 1: rock and roll lifestyle and all. So then what happens
Speaker 1: is the mixer mixes this frequency, not just it doesn't
Speaker 1: just lower. The way it lowers this frequency is it
Speaker 1: mixes the frequency with a frequency generated by an oscillator. Okay,
Speaker 1: so the oscillator creates two frequencies that are both sent
Speaker 1: into the mixer, and uh one is there the polar
Speaker 1: opposites of each other. And so the the mixer adds
Speaker 1: in the lower frequency together with the frequency that came
Speaker 1: in through the receiver, and that is what it sends
Speaker 1: out to the intermediate frequency amplifier. So we've gone PREAMPTI mixer.
Speaker 1: Mixer pulls in a second frequency from the oscillator, the
Speaker 1: oscillator frequency, the lower one gets combined with the incoming
Speaker 1: frequency that is then sent to the intermediate frequency amplifier
Speaker 1: or i F amplifier. And that just process that says
Speaker 1: is that signal and amplifies it. And we've talked about
Speaker 1: amplifiers before in this podcast, so I'm not going to
Speaker 1: get into that. Uh. And then this, this stronger signal
Speaker 1: from the i F amplifier gets sent to Well, now
Speaker 1: we've got to go to the square law detectors and
Speaker 1: the d C processors because we have to create a
Speaker 1: d see a direct current in order for that to
Speaker 1: go to a recording device. So this converts the frequency
Speaker 1: from the amplifier to direct current signals, and it smooths
Speaker 1: out the signals to make them easier to measure because
Speaker 1: they fluctuate quite a bit. Even as direct current, they
Speaker 1: tend to fluctuate. So the way they do this is
Speaker 1: they use capacitors. And if you recall we've talked about
Speaker 1: capacitors before too, capacitors store up electricity and then release
Speaker 1: it all at once, right. They're they're kind of like
Speaker 1: a battery that it can store electricity, but unlike a battery,
Speaker 1: it is and it releases all the electricity. It doesn't
Speaker 1: do a constant flow. This, by the way, is the
Speaker 1: reason why it's a bad idea to fiddle around with electronics.
Speaker 1: You don't know a lot about, including things like televisions
Speaker 1: and computers because they have capacitors in them that can
Speaker 1: store high amounts of electricity that are potentially deadly. So
Speaker 1: especially things like computers and televisions, you don't want to,
Speaker 1: you know, just knock a hole in one or you know.
Speaker 1: I have seen like videos. If you've ever seen a
Speaker 1: video of someone who who excellently breaks the television, you
Speaker 1: see a spark go off. That's a capacitor that's that's discharging,
Speaker 1: and those can be very dangerous. Chris and I have
Speaker 1: a little bit more to say about radio telescopes, but
Speaker 1: before we do, let's take another quick break to thank
Speaker 1: our sponsor. I have read an interesting analogy which said,
Speaker 1: imagine that you have a water hose and water is
Speaker 1: moving through the hose, but the pressure keeps changing, so
Speaker 1: the water sometimes it's flowing out very quickly and sometimes
Speaker 1: it's sputtering out. Okay uh. In the case of this
Speaker 1: detecting radio frequencies, you want to a steady um flow
Speaker 1: so that you can measure it properly. So what if
Speaker 1: you were to instead of just measure the measuring the
Speaker 1: water that comes out of the hose, you you direct
Speaker 1: the hose towards a bucket, okay, and at the base
Speaker 1: of the bucket there's this big it that you can
Speaker 1: open up. Well, if you open up the spin on
Speaker 1: the bucket, water is going to flow out at a
Speaker 1: much more steady rate than it's flowing out of the hose.
Speaker 1: That's the kind of idea here with the capacitor, and
Speaker 1: that it's to try and smooth out that signal and
Speaker 1: make it easier to record, and then finally you've got
Speaker 1: the actual recording device. Now, in the old days, the
Speaker 1: recording device was a an old man who said what
Speaker 1: is that? No, it was actually a pen attached to
Speaker 1: a a movable arm and some paper that was pulled
Speaker 1: across and then the movable arm would would move depending
Speaker 1: upon changes in voltage. And so it's very similar to
Speaker 1: uh earthquake detecting equipment. We talked about seismological equipment in
Speaker 1: the past where you see that or even if you
Speaker 1: think also a similar things light detectors, that's what I
Speaker 1: was saying, polygraphs where they have the little the little
Speaker 1: pen that scratches back and forth across the papers, the
Speaker 1: papers going by, similar kind of thing. Um Now in
Speaker 1: October fourteen, yeah, so we when did you go super nova. Um. No,
Speaker 1: so this in this case instead, what's doing is it's
Speaker 1: actually uh, modern ones don't tend to use this anymore.
Speaker 1: They tend to actually send the data directly to a
Speaker 1: computer where it gets recorded and you read out the
Speaker 1: information on a computer screen, as opposed to looking at
Speaker 1: a physical representation scratched out in pen um. That's generally
Speaker 1: how the radio telescope works from start to finish. So
Speaker 1: it's pretty interesting stuff. It's a little complex, I would say, yeah, yeah, Um.
Speaker 1: One of the things that uh, we were talking about
Speaker 1: two Jonathan mentioned, um the Jansky's experiments where he was
Speaker 1: he would note that the interference would come around at
Speaker 1: a certain period of time. UM. One of the prime
Speaker 1: places to put a radio telescope is near the equator
Speaker 1: because it is really good. Um. It's a really good
Speaker 1: place to get an accurate depiction as the Earth rotates, um,
Speaker 1: and it can it can identify sources of radio information
Speaker 1: coming from space very clearly. UM. Unfortunately, it's a rather
Speaker 1: expensive place to try to build a radio telescopes, and
Speaker 1: that's one of the reasons why they can be found
Speaker 1: in many different places around the world. But yea closer
Speaker 1: to the equator tends to be better just for the
Speaker 1: you know, the quality of information you can get from this.
Speaker 1: UM and and uh, we've actually started using radio telescopes
Speaker 1: to kind of map out the celestial bodies around us,
Speaker 1: even ones that are not visible to the naked eye.
Speaker 1: And it's been very useful for astronomers. And there's still
Speaker 1: there's still even you know, uh, amateur astronomers who use
Speaker 1: radio telescopes. This this it's not just the realm of
Speaker 1: massive scientific organizations like NASA, although I mean those are
Speaker 1: the ones that you know, if you look up the
Speaker 1: pictures online, you tend to see the really larger arrays
Speaker 1: or really large antennas that belonged to these major organizations. Now,
Speaker 1: a radio telescope is able to detect things celestial bodies
Speaker 1: and sky by their angular resolution. UM. Basically it it
Speaker 1: really is contingent on the wavelengths that it is able
Speaker 1: to detect. So that's one of the reasons why UM,
Speaker 1: a radio telescope does need to be large. UM. Yeah,
Speaker 1: if you you could build a small one, but it
Speaker 1: wouldn't be nearly as functional as a larger one. Basically,
Speaker 1: the larger radio telescope is the greater it's angular resolution. Um.
Speaker 1: But um that that's basically uh, that's basically what it is.
Speaker 1: What what it's using. In terms of how you would
Speaker 1: measure the effectiveness of a radio telescope. Yeah, if you
Speaker 1: you know, if you had like a backyard telescope visual telescope,
Speaker 1: the resolution you would get on that is equivalent to
Speaker 1: what you would get with a huge radio telescope. The
Speaker 1: solution on a radio telescope is proportional to its size.
Speaker 1: So um, yeah, you've gotta have a big one if
Speaker 1: you're going to have any any real precise resolution. And
Speaker 1: again we're not, you know, it's it's a little weird
Speaker 1: because it's hard to think of resolution in terms of
Speaker 1: something other than visible light because that's what we're mostly
Speaker 1: familiar with. But but yes, it's it still applies in
Speaker 1: this case. Yep, yep, um and radio basically, radio astronomers
Speaker 1: have been able to detect all kinds of different molecules
Speaker 1: in space too. Um, you can. You might be surprised
Speaker 1: to learn. I was a little surprised to learn that
Speaker 1: radio radio astronomers were able to identify carbon dioxide, water, formaldehyde,
Speaker 1: ethyl alcohol, methanol, ammonia, UM and all kinds of other
Speaker 1: different kinds of just that kinds twice of compounds out
Speaker 1: in space UM and and to use the radio telescope
Speaker 1: in that way, I mean it's you can get a
Speaker 1: lot of information. And that's actually uh sort of ties
Speaker 1: back into the SETI project because the if if you
Speaker 1: haven't listened to that particular podcast or are unfamiliar with
Speaker 1: the project, Basically, UM astronomers were collecting large amounts of
Speaker 1: data from the radio telescope. They were using UM for
Speaker 1: their project, and the thing is their computers couldn't analyze
Speaker 1: it all at one time. They were collecting so much
Speaker 1: that it was just stacking up essentially, not literally but
Speaker 1: to figurative. To create an analogy, We've talked about in
Speaker 1: the past, how on YouTube, users are uploading forty eight
Speaker 1: hours of content every every minute. So it'd be like
Speaker 1: telling one person to watch everything that's on YouTube. You've
Speaker 1: got you've got a growing amount of content that you're
Speaker 1: never going to catch up to and only so much
Speaker 1: ability to consume it. So same sort of thing. In
Speaker 1: this case, we're talking about generating uh, incredible amounts of
Speaker 1: data and having a limited ability to actually analyze the information.
Speaker 1: So what they would do was to break it down
Speaker 1: and use it in a distributed computing project, which they
Speaker 1: were calling SETI at Home, and the idea being that
Speaker 1: people take a slice of information, allow their computers to
Speaker 1: work it out using a specially designed program, and send
Speaker 1: it back to the astronomers so that they could evaluate
Speaker 1: it and added to the project. And uh, you know,
Speaker 1: it's just sort of a kind of a neat way
Speaker 1: to to get into helping out with the project like that.
Speaker 1: But that's that's one of the problems, a good problem
Speaker 1: to have with with radio astronomy is that these uh
Speaker 1: large radio telescopes can couldn't collect an awful lot of data. Yeah,
Speaker 1: and so we might use them to discover things like
Speaker 1: quay stars re pulsars that we had never seen before,
Speaker 1: or even detect the presence of a galaxy that before
Speaker 1: this point we just didn't know existed. Now. CETI, of course,
Speaker 1: was really looking for any sort of signals that might
Speaker 1: indicate a pattern or uh a possible um well possible
Speaker 1: hint that there's some sort of other intelligent life out
Speaker 1: there that's generating these signals, not not just some natural phenomenon.
Speaker 1: Do do do do well? Um and radio. Radio telescopes
Speaker 1: can also detect information about near celestial bodies as well.
Speaker 1: The surface. For the Moon, we knew it was sort
Speaker 1: of sandy before people actually landed there because astronomers had
Speaker 1: used radio telescopes to, uh to get signals from the
Speaker 1: Moon and learn, you know, what it was like. They're
Speaker 1: also Venus, you know, is shrouded by clouds, but astronomers
Speaker 1: are able to learn more about the surface by using
Speaker 1: radio telescopes and radar to get an idea of what
Speaker 1: these the actual planet surfaces. Well, they've also used it
Speaker 1: to observe the storms on Jupiter, so that's kind of
Speaker 1: interesting too, Like they just looked at the weather report
Speaker 1: for you right today today it's gonna be a big gas.
Speaker 1: It sounds like my never mind never yes, let's it's
Speaker 1: most like that, Okay, but yeah, I think, uh, it's
Speaker 1: it's an interesting topic. It's really and it's one honestly
Speaker 1: I did not know very much about before we started
Speaker 1: researching this podcast. I agree with you. I mean I
Speaker 1: knew of it, I knew it existed, but I didn't
Speaker 1: really understand what it was doing or how it did it.
Speaker 1: And it is pretty cool. I mean, it just shows
Speaker 1: me that radio is way cooler than I ever imagined
Speaker 1: when I you know, so there you turn a radio on.
Speaker 1: That's that's the extent of your Maybe you play with
Speaker 1: a walkie talkie, but that's about it as far as
Speaker 1: radio goes. And then the more you look into it,
Speaker 1: the more you're like, wow, this is really phenomenal stuff.
Speaker 1: Tesla was onto something. It's gonna say you probably had
Speaker 1: a patent for that. Yeah, I probably did. And then
Speaker 1: never mind, I'm not gonna go into another Tesla rent. Okay.
Speaker 1: Then all right, Well that wraps up this discussion. Minka,
Speaker 1: thank you so much for writing in and jesting that
Speaker 1: that was a really cool topic for us to tackle.
Speaker 1: And that wraps up another classic episode of tech Stuff.
Speaker 1: I hope you guys enjoyed it. It's always a joy
Speaker 1: to look into tech with Chris. I hope he's doing well.
Speaker 1: I cannot get him back on the show because he's
Speaker 1: got better things to do than to sit across the
Speaker 1: table and talk into a microphone with me. He's doing
Speaker 1: important work like making people way way smarter. So, Chris,
Speaker 1: if you're listening, thanks so much. There's a joy to
Speaker 1: work with you, and it's always fun to listen back
Speaker 1: to these old episodes. If you want to reach out
Speaker 1: and suggest new topics for me to cover in future
Speaker 1: episodes of tech Stuff, go visit our website, it is
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