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Speaker 1: tech Stuff. Hello everyone, and welcome to tech Stuff. My
Speaker 1: name is Chris Poulette and I am an editor at
Speaker 1: how stuff works dot com. Sitting here across from me.
Speaker 1: A guy who used to be an adventurer like you
Speaker 1: until he took an arrow to the knee is senior
Speaker 1: writer Jonathan Strickland. The sky above the port was the
Speaker 1: color of television. Tune to a dead channel. It's good guy, Okay,
Speaker 1: So um, before we get started, we're gonna do something
Speaker 1: we haven't done a little while. Yeah, we're gonna listen
Speaker 1: to a little listener mail. This listener mail comes from Minka,
Speaker 1: who says I love your podcast and have enjoyed listening
Speaker 1: to your incifle and quirky explanations immensely. I tried to
Speaker 1: search through the past podcast to see if you have
Speaker 1: done one on radio telescopes, to no avail, So I
Speaker 1: hope I didn't just miss it. It seems to me
Speaker 1: that radio telescopes are being used frequently to learn about
Speaker 1: this and study the far reaches of the galaxy and beyond,
Speaker 1: and it's pretty darn cool, so it'd be neat to
Speaker 1: learn more about how they work. Thanks and thanks for
Speaker 1: the show, Minka. Well you're welcome, Minga. I just wanted
Speaker 1: to say you're welcome, all right. So now we're moving
Speaker 1: on to our topic, the Smurfs. No No, we're gonna
Speaker 1: talk about radio telescopes. Yeah, we sort of. Well, we've
Speaker 1: talked about things that relate to radio telescopes like radio
Speaker 1: and set yes and set CD, which does very much
Speaker 1: 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, because they're my notes crashed, so I don't
Speaker 1: know what I'm talking about. I'm not I'm just kidding.
Speaker 1: They're still up. He can't see my computer from where
Speaker 1: he sits. Yes, because he's sitting directly across from me. Yes.
Speaker 1: See if if you ever wondered if that was true
Speaker 1: or not, it is. Yeah, um no, it's it's actually
Speaker 1: using It's unlike a typical visual telescope, which uses lenses
Speaker 1: and your eyeball and you look through it and you
Speaker 1: look for stuff on the other side and base it
Speaker 1: directs light which is in the visible spectrum of the
Speaker 1: electromagnetic frequency to our to our eyeballs. Ultimately right, right,
Speaker 1: But and again another drastic oversimplification of the parts. But
Speaker 1: a radio telescope is actually monitoring different parts of the
Speaker 1: electromagnetic frequency. Yeah, yeah, it's good looking at a completely
Speaker 1: different spectrum, So this is part of the spectrum that
Speaker 1: is not visible to the naked eye. So we are
Speaker 1: using these telescopes to measure um radio frequency variations that
Speaker 1: come from outer space. And it turns out that lots
Speaker 1: of stuff out there generates radio frequencies, right, So things
Speaker 1: like quasars, pulsars, galaxies, uh, distant stars, these sort of
Speaker 1: things can generate electromagnetic radiation and in the form of
Speaker 1: radio frequencies. And sometimes these are are objects that we
Speaker 1: can't detect visually, but we can detect them if we
Speaker 1: have a sensitive enough tool that can can detect and
Speaker 1: measure radio frequencies. So that's really what a radio telescope
Speaker 1: is all about. And it's kind of tricky picking up
Speaker 1: radio frequencies from outer space because only certain the actual
Speaker 1: band of frequencies or wavelengths I should say, the band
Speaker 1: of wavelengths that exist within the electromatic magnetic spectrum that
Speaker 1: our radio frequency waves. It's pretty broad, Yeah, about ten
Speaker 1: meters and to one millimeter. That's a pretty good size. Yeah,
Speaker 1: you can actually get radio waves that are even longer
Speaker 1: than that, like the size of football fields. But here's
Speaker 1: the thing is that the Earth has a level of
Speaker 1: the atmosphere called the iona sphere. Now, the iona sphere
Speaker 1: is uh, it's kind of funky. So you guys probably
Speaker 1: have heard us talk about ions before, you know. That's
Speaker 1: when we're talking about uh, atoms that have either gained
Speaker 1: or lost an electron. And if you ionize something, that
Speaker 1: means you've got some free electrons roaming around in it.
Speaker 1: So like an ionized gas or a plasma can actually
Speaker 1: hold carry an electric charge. Right, Yes, why are you
Speaker 1: smiling at me just because I saw a whole bunch
Speaker 1: of people going free electrons? Yeah, they're so expensive otherwise
Speaker 1: that's true. Have you seen my electric bill? Anyway? So
Speaker 1: you have the ionosphere, whether these free roaming electrons out there,
Speaker 1: and uh, and it kind of acts as a bit
Speaker 1: of a a shield or reflector in in some ways.
Speaker 1: And so radio waves of a certain wavelength cannot pass
Speaker 1: through the ionosphere. Essentially, anything that's ten meters are longer.
Speaker 1: The ionosphere is opaque to those. That's why you can
Speaker 1: actually broadcast certain long wavelength radio waves uh and bank
Speaker 1: them off the ionosphere, right because it won't pass through. Now,
Speaker 1: when you start getting shorter than a ten meter wave length,
Speaker 1: you have radio waves that can pass through the ionosphere.
Speaker 1: But if it's longer than twenty centimeters, which is about
Speaker 1: one point five gig hurts in frequency when you're talking
Speaker 1: about these, If it's longer than twenty centimeters, you start
Speaker 1: to have distortion as it passes through the ionosphere. It's
Speaker 1: called scintillation. And this isn't that different from the way
Speaker 1: when we look up into the sky and we see
Speaker 1: stars twinkling. That's sort of the same sort of thing
Speaker 1: we talked about being scintillating, same kind of idea, except
Speaker 1: in this case. You know, that's we're talking about the
Speaker 1: visual spectrum there, but here, Yeah, the twenty centimeters are longer,
Speaker 1: you run into that problem, and so that's not entirely
Speaker 1: useful for measurement purposes. So radio telescopes tend to focus
Speaker 1: on pun intended uh. Wavelengths that are between one centimeter
Speaker 1: and twenty centimeters in length tend to Now there are
Speaker 1: some variations, and also if you were to have a
Speaker 1: radio tell scope, say in orbit, where it's you know,
Speaker 1: you don't have the ionosphere as a in play. Um,
Speaker 1: that's a different story. But ground based radio telescopes kind
Speaker 1: of had to play within these rules because the way
Speaker 1: the ionosphere works. One of the nice things though about
Speaker 1: the radio telescope is that, uh, those frequencies generally come
Speaker 1: through pretty clearly. So uh, putting one of the ground
Speaker 1: based radio telescopes in orbit really wouldn't improve its ability
Speaker 1: to detect signals, UM, at least based on my research,
Speaker 1: not not within anything that's within those wavelengths. Yeah. Actually,
Speaker 1: it's it's a little tricky to detect that stuff anyway,
Speaker 1: because we're talking about really weak signals. I mean, by
Speaker 1: the time they reached the Earth, that these signals are
Speaker 1: not very strong at all. In fact, one one reference
Speaker 1: I I looked at said that, um that if you
Speaker 1: were to add up all the energy that every radio
Speaker 1: telescope on Earth had been subjected to since they were built,
Speaker 1: it still would not equal the energy would find in
Speaker 1: the snowflake. Yeah, that's pretty impressive. Actor. Now, grant that
Speaker 1: snowflake is the size of Detroit. No, I'm kidding, I'm kidding,
Speaker 1: typical snowflake. No. Uh. And it is also worthwhile to note,
Speaker 1: especially before anyone writes in UM, that radio telescopes do
Speaker 1: have to be placed away from population centers in general, uh,
Speaker 1: to some degree to because there is earthly interference. Yeah,
Speaker 1: those terrestrial radio interference that you have to try and
Speaker 1: minimize as much as possible. Otherwise it's just so much
Speaker 1: noise that you're not going to even find any signal
Speaker 1: out there, right right, So, um, yeah, it has its
Speaker 1: it has its good points and it's bad points simply
Speaker 1: because of the the frequencies it's able to monitor. And
Speaker 1: it's a good point too that you uh you mentioned
Speaker 1: the from the very first because these these devices. I mean,
Speaker 1: I imagine people you know, have a good idea what
Speaker 1: radio telescopes look like. I mean, we've all seen satellite dishes,
Speaker 1: and to some degree that's more or less what they
Speaker 1: look like. In fact, you may have seen pictures of them.
Speaker 1: But um, that I think gives it the this sort
Speaker 1: of feeling that it's a fairly recent thing. And in fact,
Speaker 1: um it was somebody in uh nineteen thirty three who
Speaker 1: who figured out that um there was uh, there were
Speaker 1: radio frequencies coming from extraterrestrial bodies, someone at of course
Speaker 1: Bell telephone laboratories. You always do that. I can't fight
Speaker 1: it that, I can't fight this feeling anymore. I can't.
Speaker 1: But yes, so you're talking about Carl Carl Jansky. Carl Jansky, Yes, uh.
Speaker 1: He he built the first antenna that could be used
Speaker 1: as a radio telescope back in nineteen thirty one, but
Speaker 1: it would take a couple of years to really figure out, uh,
Speaker 1: the fact that you could use this to to explore
Speaker 1: the 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 it 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 you to
Speaker 1: come back round, so that you're pointing at that same object.
Speaker 1: This will 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 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 antennas, including
Speaker 1: dipole antenna's, cylindrical parabolics, which are they kind of look
Speaker 1: like a trough. Uh. There are the yaggy antenna's, which
Speaker 1: are um not little guys who teach you how to
Speaker 1: use kung fu karate, I should say, their horn antennas,
Speaker 1: their mills crosses that kind of stuff. Mills crosses. Telescope
Speaker 1: is 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 our and the parabolic style of
Speaker 1: of antenna, this is why you have that big dish.
Speaker 1: The dish part is actually reflecting um frequencies so that
Speaker 1: they all are directed to a single focal point and
Speaker 1: that's usually called the feed that's usually a small antenta
Speaker 1: called the feed that us often called the feed horn
Speaker 1: that will 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: they're so so delicate. There's so such tiny little frequencies
Speaker 1: 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 sensitive things. And also the amount of information
Speaker 1: you can get is very much connected to the size
Speaker 1: of your antenna. Bigger antennas are able to provide a
Speaker 1: higher resolution image. It's kind of a weird word to say,
Speaker 1: because we're not talking about visible light necessarily, but an
Speaker 1: 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, while uh, we know that by designing
Speaker 1: an antenna of this size, this particular warping is going
Speaker 1: to occur, so we have to factor that into the
Speaker 1: design so that the warping actually ends up helping rather
Speaker 1: than hurting. And usually you do that by adding a
Speaker 1: second reflector that is that's movable, so you can have
Speaker 1: a second reflector actually um position in such a way
Speaker 1: where the distortion from the main reflector hits the second reflector,
Speaker 1: which then reflects it back to the focal point, so
Speaker 1: it gets a little complicated. In fact, there are two
Speaker 1: main types of secondary reflectors. There's the Cassegrain focus, which
Speaker 1: is a reflector that's in front of the main antenna
Speaker 1: or the main reflector, i should say. And then there's
Speaker 1: another one if you have it in the back. It's
Speaker 1: called Grigoryan focus, and it chants a lot feeling you
Speaker 1: were going to say that, yeah, there was a pretty
Speaker 1: good chance. Uh, yeah, it's possible. Um. Now, given what
Speaker 1: what Jonathan 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 or cold, because the materials will expand or
Speaker 1: contract right wind the surface of the material itself, the
Speaker 1: surface of the material itself. Um. But other than that,
Speaker 1: I mean, once you take all these things into account,
Speaker 1: it is theoretically possible to build as large a radio
Speaker 1: telescope as you possibly can. There's really no limit to
Speaker 1: the size other than the fact that you're going to
Speaker 1: have to take things like gravity and temperature and things
Speaker 1: like that into a tensile strength. But conceivably, if you
Speaker 1: could build one that's three times the size of Earth,
Speaker 1: it would work. But that and that's fascinating because it's
Speaker 1: it's not it doesn't have to be a particularly large
Speaker 1: or particularly small device. It just you know, you can
Speaker 1: pick up more with it. And a lot of a
Speaker 1: lot of radio telescopes are actually telescope like antenna a rays,
Speaker 1: so it's not just one antenna's several antenna's working together
Speaker 1: in order for you to gather this information, and that
Speaker 1: that helps you create a larger radio telescope just but
Speaker 1: you know, you're adding extra elements in. It means that
Speaker 1: you sort of get around part of the problem, which is,
Speaker 1: you know, building just an enormous single antenna. You can
Speaker 1: do an array of antennas. There are different limitations on
Speaker 1: this as well. Um So the signal that you're picking
Speaker 1: up with this radio telescope is really really weak, So
Speaker 1: in order for you to have it and to to
Speaker 1: transmit first you have to you have to transfer the
Speaker 1: radio frequency information by by changing it into electricity. But
Speaker 1: because the frequency signal is so weak, the electric current
Speaker 1: would be pretty pathetic. You would not be able to
Speaker 1: measure it just by converting it right from radio frequency
Speaker 1: to electricity without amplifying it in some way. So typically
Speaker 1: a radio telescope will then have a pre amplifier. So
Speaker 1: you musicians out there and and and radio folks, you know,
Speaker 1: you're probably pretty familiar with the idea of a pre amplifier.
Speaker 1: Microphones usually have a pre amplifier, that kind of thing. Um,
Speaker 1: So a pre amplifier is really just a a way
Speaker 1: of boosting a signal a certain amount before it gets
Speaker 1: truly amplified, uh, for the final use of whatever that
Speaker 1: signal is gonna be, whether it's in the audio industry
Speaker 1: or in this case, the measuring the celestial bodies. Yeah,
Speaker 1: I was I was gonna say that they don't necessarily
Speaker 1: usually have them anyway. Um, well, that's that's fair, but
Speaker 1: it does it does assist, uh, and in picking up
Speaker 1: these weak signals, that's for sure. Yeah. And so the
Speaker 1: kind that tends to be used in radio telescopes are
Speaker 1: called low noise amplifiers because we're talking about such small,
Speaker 1: very very quiet and signals. And so, boy, I'm glad
Speaker 1: didn't do the old listener mail will be getting because
Speaker 1: then it with all this, it would have probly blown
Speaker 1: everybody's ears out. So the the these l n A
Speaker 1: pre amplifiers take these um signals and then they boost
Speaker 1: them now here's the thing. Any sort of interference at
Speaker 1: this point could really compromise the measurements you're making. So
Speaker 1: that includes molecular movement of the pre amp. So the
Speaker 1: fact that you know, everything in matter is made up
Speaker 1: of molecules, and these molecules move even in solid objects, right,
Speaker 1: So they in in a in big radio telescope facilities,
Speaker 1: things like the professional ones that you would find in
Speaker 1: say NASA, they tend to have to cool down the
Speaker 1: pre amplifier to reduce molecular movement as much as possible,
Speaker 1: and usually to around ten kelvin. It's pretty cold. Pretty cold, yeah,
Speaker 1: zero kelvin means no molecular movement. That's what like the
Speaker 1: deepest reaches of space would be zero kelvin. So ten
Speaker 1: kelvin's pretty cold. They tend to use liquid helium to
Speaker 1: cool down the this this device low enough so that
Speaker 1: it reduces the chance for it to contribute noise to
Speaker 1: this signal. All right. From there, the signal moves into
Speaker 1: a mixer, yes, where it has a party and networks
Speaker 1: with people and not. Oh, should have taken different notes. Okay,
Speaker 1: well I'll just work from memory here then. Um No,
Speaker 1: a mixer, what the mixer's purpose is to change the
Speaker 1: frequency of the signal. Now, these signals are very high
Speaker 1: frequency and UH, and it turns out that it's easier
Speaker 1: to amplify lower frequencies. It's possible to amplify higher frequencies,
Speaker 1: but in general, it takes less UH effort to amplify
Speaker 1: the lower frequency signals. And if it's kept at it's
Speaker 1: high frequency and you're just you're you're working with the
Speaker 1: frequency at that and it's native frequency, there's the chance
Speaker 1: that will travel back up the antenna and create feedback.
Speaker 1: It's not dissimilar to what would happen with a microphone
Speaker 1: too close to a speaker, where you get that wonderful
Speaker 1: sound that's not wonderful. Now you're you're probably more familiar
Speaker 1: with it than I am, with your rock and roll
Speaker 1: lifestyle and all. So then what happens is the mixer
Speaker 1: mixes this frequency, not just it doesn't just lower. The
Speaker 1: way it lowers this frequency is it mixes the frequency
Speaker 1: with a frequency generated by an oscillator. Okay, so the
Speaker 1: oscillator creates two frequencies that are both sent into the
Speaker 1: mixer and UH one is their polar opposites of each other,
Speaker 1: and So the the mixer adds in the lower frequency
Speaker 1: together with the frequency that came in through the receiver,
Speaker 1: and that is what it sends out to the intermediate
Speaker 1: frequency amplifier. So we've gone PREAMPTI mixer. Mixer pulls in
Speaker 1: a second frequency from the oscillator. The oscillator frequency, the
Speaker 1: lower one, gets combined with the incoming frequency that is
Speaker 1: then sent to the intermediate frequency amplifier or I of amplifier,
Speaker 1: and that just process that sesses that signal and amplifies it.
Speaker 1: We've talked about amplifiers before in this podcast, so I'm
Speaker 1: not going to get into that. Uh. And then this
Speaker 1: this stronger signal from the I F amplifier gets sent
Speaker 1: to Well, now we've got to go to the square
Speaker 1: law detectors and the d C processors because we have
Speaker 1: to create a d C a direct current in order
Speaker 1: for that to go to a recording device. So this
Speaker 1: converts the frequency from the amplifier to direct current signals,
Speaker 1: and it smooths out the signals to make them easier
Speaker 1: to measure because they fluctuate quite a bit. Even as
Speaker 1: direct current, they tend to fluctuate. So the way they
Speaker 1: do this is they use capacitors. And if you recall
Speaker 1: we've talked about capacitors before too, capacitors store up electricity
Speaker 1: and then release it all at once, right there. They're
Speaker 1: kind of like a battery that it can store electricity,
Speaker 1: but unlike a battery, it is and it releases all
Speaker 1: the electricity, doesn't do a constant flow. This, by the way,
Speaker 1: is the reason why it's a bad idea to fiddle
Speaker 1: around with electronics you don't know a lot about, including
Speaker 1: things like televisions and computers, because they have capacitors in
Speaker 1: them that can store high amounts of electricity that are
Speaker 1: potentially deadly. So, especially things like computers and televisions, you
Speaker 1: don't wanna, you know, just knock a hole in one,
Speaker 1: or you know, I've seen like videos, if you've ever
Speaker 1: seen a video of someone who who accellently breaks the television,
Speaker 1: you see a spark go off. That's a capacitor that's
Speaker 1: that's discharging, and those can be very dangerous. So anyway,
Speaker 1: in this case, the capacitors are used to kind of
Speaker 1: smooth out those signals. I have read an interesting analogy
Speaker 1: which said, imagine that you have a water hose and
Speaker 1: water is moving through the hose, but the pressure keeps changing,
Speaker 1: so the water sometimes it's flowing out very quickly and
Speaker 1: sometimes it's sputtering out. Okay. Uh. In the case of
Speaker 1: this detecting radio frequencies, you want to a steady um
Speaker 1: flow so that you can measure it properly. So what
Speaker 1: if you were to instead of just measure the measuring
Speaker 1: the water that comes out of the hose, you you
Speaker 1: direct the hose towards a bucket, okay, And at the
Speaker 1: base of the bucket there's a spigot that you can
Speaker 1: open up. Well, if you open up the spigot 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: was 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 uh,
Speaker 1: earthquake detecting equipment. We've talked about seismological equipment in the
Speaker 1: past where you see that or even if you think
Speaker 1: also similar things lie detectors. That's exactly what I was thinking.
Speaker 1: Polygraphs where they have the little the little pen that
Speaker 1: scratches back and forth across the papers, the papers going by,
Speaker 1: similar kind of thing. Um, now you were in October fourteen. Yeah,
Speaker 1: so we tell you when did you go super nova? Um? No,
Speaker 1: so this in this case instead, what it's doing is
Speaker 1: it's 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 we were talking about two
Speaker 1: Jonathan mentioned, um the Jansky's experiments where he was he
Speaker 1: would note that the interference would come around it these
Speaker 1: certain period of time. UM. One of the prime places
Speaker 1: to put a radio telescope is near the equator because
Speaker 1: it is really good. Um, it's a really good place
Speaker 1: 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 telescope, and
Speaker 1: that's one of the reasons why they can be found
Speaker 1: in many different places around the world. But yeah, 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 telescope. This it's 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 belong to these major organizations. Now,
Speaker 1: a radio telescope is able to detect things celestial bodies
Speaker 1: in the sky by their angular resolution. Um. Basically it
Speaker 1: it really is contingent on the wavelengths that it is
Speaker 1: able 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: resolution 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. YEA UM and radio. Basically radio astronomers have
Speaker 1: been able to detect all kinds of different molecules in
Speaker 1: space too. UM. You can you might be surprised to learn.
Speaker 1: I was a little surprised to learn that radio radio
Speaker 1: astronomers were able to identify carbon dioxide, water, formaldehyde, ethyl alcohol, methanol,
Speaker 1: and na um and all kinds of other different kinds
Speaker 1: of just that kinds choice of compounds out in space
Speaker 1: UM and and to use the radio telescope in that way,
Speaker 1: I mean, it's you can get a lot of information.
Speaker 1: And that's actually uh sort of ties back into the
Speaker 1: set project because the if if you haven't listened to
Speaker 1: that particular podcast or are unfamiliar with the project, Basically,
Speaker 1: UM astronomers were collecting large amounts of data from the
Speaker 1: radio telescope. They were using UM for their project, and
Speaker 1: the thing is their computers couldn't analyze it all at
Speaker 1: one time. They were collecting so much that it was
Speaker 1: just stacking up essentially, not literally, but to figure it
Speaker 1: in to create an analogy we've talked about in the past,
Speaker 1: how on YouTube users are uploading forty eight hours of
Speaker 1: content every every minute, So it'd be like telling one
Speaker 1: person to watch everything that's on YouTube. You've got you've
Speaker 1: got a growing amount of content that you're never going
Speaker 1: to catch up to and only so much ability to
Speaker 1: consume it. So same sort of thing. In this case,
Speaker 1: we're talking about generating uh, incredible amounts of data and
Speaker 1: having a limited ability to actually analyze the information. So
Speaker 1: what they would do was to break it down and
Speaker 1: use it in a distributed computing project, which they were
Speaker 1: calling Steady at Home, and the idea being that people
Speaker 1: take a slice of information, allow their computers to work
Speaker 1: it out using a specially designed program, and send it
Speaker 1: back to the astronomers so that they could evaluate it
Speaker 1: and add it to the project. And uh, you know,
Speaker 1: it's just sort of a kind of a neat way
Speaker 1: 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: quaysars and pulsars that we had never seen before, or
Speaker 1: even detect the presence of a galaxy that before this
Speaker 1: point we just didn't know existed. Uh. Now, Cetti, 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. Uh,
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: the actual planet surfaces. Well, they've also used it to
Speaker 1: observe the storms on Jupiter, so that's kind of interesting too.
Speaker 1: Like they just looked at the weather report for to
Speaker 1: right today today it's gonna be a big gas. It
Speaker 1: sounds like my never mind, never mind, Yes, just think that. Okay,
Speaker 1: but yeah, I think, uh, it's it's an interesting topic.
Speaker 1: It's really and it's one honestly I did not know
Speaker 1: very much about before we started researching this podcast. No,
Speaker 1: I agree with you. I mean I knew of it,
Speaker 1: I knew it existed, but I didn't really understand what
Speaker 1: it was doing or how it did it. And it
Speaker 1: is pretty cool. I mean, it just shows me that
Speaker 1: radio is way cooler than I ever imagined when I
Speaker 1: you know, so there you turn a radio on. That's
Speaker 1: that's the extent of your Maybe you play with a
Speaker 1: walkie talkie, but that's about it as far as radio goes.
Speaker 1: And then the more you look into it, the more
Speaker 1: you're like, wow, this is really phenomenal stuff. Tesla was
Speaker 1: onto something. I'm gonna say you probably had a patent
Speaker 1: for that. Yeah, I probably did. And then never mind,
Speaker 1: I'm not gonna go into another Tesla rent. Okay. Then
Speaker 1: all right, Well that wraps up this discussion. Minka. Thank
Speaker 1: you so much for writing in and suggesting that that
Speaker 1: was a really cool topic for us to tackle. If
Speaker 1: any of you have a topic you would like us
Speaker 1: to look at in a future episode of tech stuff.
Speaker 1: You can let us know on Twitter or Facebook are handled.
Speaker 1: There is text stuff hs W and I promise we're
Speaker 1: gonna have a new email for you soon. We just
Speaker 1: haven't created that new email address on our new email platform. Um,
Speaker 1: you can try sending it to the old one, but
Speaker 1: there's no guarantee get to us. But as soon as
Speaker 1: we have a new one, I'll let you guys know.
Speaker 1: So that'll wrap this up and Chris and I will
Speaker 1: talk to you again really soon. This podcast is brought
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