INTERVIEW: SHUBHAM KANODIA

CO-AUTHOR OF How MUCH SETI HAS BEEN DONE?

EPISODE TRANSCRIPT

Ray Tarara: If you could start with just introducing yourself, what's your name and what do you do.

Shubham Kanodia: My name is Shubham Kanodia, and I am a graduate student in the Astronomy Department at Pennsylvania State University. I work on exoplanet research as well as SETI.

Ray: How did you get interested in SETI research?

Shubham: I started working on SETI as part of this graduate course that I took with Professor Jason Wright, and I was initially interested in learning more about the field because it's a topic that I guess fascinates pretty much everyone, but I wanted to see how I can contribute to the topic in a more quantitative manner.

Ray: Through that, you coauthored your paper, how much study has been done, Finding Needles in the N-dimensional Cosmic Haystack. What specifically about that topic of trying to quantify, how much search has been done, drew you to it?

Shubham: That started off as a project of basically, as it says, how much searching has been done. There were other aspects of SETI that I could have worked on because you had to do this class project, but this seemed the most exciting thing, maybe that this involves some heavy mathematical lifting which was needed to come up with this framework which you can use to take all the searches that have been done so far, put them in the system and split out numbers, which tell you how effective or what fraction of the volume that they calculated or did they cover. We came up-- The framework itself is not something that is new, in the sense, the idea has been proposed. It was proposed in the '80s by Jill Tarter. What we did is we provided a lot more rigorous framework where we took all the eight, nine dimensions and put them in one mathematical formula so that you can just take your search parameters, put them in that formula, and the formula will tell you that according to these assumptions that have been made for the framework and for this framework, which is valuing these parameters, this is how effective your search has been.

Ray: How does that framework determine what parts of the galaxy are searchable from earth? Like what is it comparing your search parameters against?

Shubham: The typical cosmic haystack has nine parameters. You have the three distance dimensions. You have the frequency of the transmission, so what frequency, is it in the radio, is that in the optical, is it in the infrared. If in the radio, which is what we've limited this haystack to, which wave-band. That's the fourth one. Then you have the transmission bandwidth, how wide is the signal, is it a really narrow-band signal, what is the spectral width of the signal. That's number five. Number six, I believe is the repetition rate, how frequently does the signal get repeated. That is basically to quantify that if I am staring at this patch of the sky every day for one hour as an example, will I see the signal? The signal is repeating once every year and you're just going to look at it for one month, the odds are you're going to have a hard time trying to find it. That's what the period dimension tries to capture. Then you have the polarization, what's the polarization of the light, is it circularly polarized, is it linearly polarized and so on. I think the last dimension is the modulation and that is something we did not cover. We mentioned it, but we did not cover it, simply because it included many things that could not be captured in a very simple and succinct manner and that involved a lot more calculations that we did not want to go into right now, because that also involves dealing with what kind of algorithms they use for the searches. That is something we did not want to include in this framework. I guess the last dimension, which is the most important, is the sensitivity. Basically how sensitive is your receiver. We took these nine dimensions-- Well, eight dimensions and then put them together. To answer your question, for example, what part of galaxy you are looking into, we made this framework completely agnostic of which direction you're pointing your telescope at. There were some other versions of this framework that have been computed before which did not look at just a solid angle or how much of the sky you're pointing at, but how many stars are you pointing at. They tried to quantify this dimension in the context of if I'm looking at 10 stars in the galaxies, that's 10 stars out of, let's say, a trillion stars. That's your fraction, 10 out of 1 trillion. What we did is we did not look at the number of stars we are pointing at but just what fraction of the sky. That's how we're quantifying the spatial dimension, just what fraction of the sky you're looking at. That's the reason this is just one way this framework can be constructed, We could have taken another approach, instead of looking at the solid angle or the fraction of the sky, we could have looked at the number of stars. Because of the decision we made, the search which covers the largest volume in our framework is the one which has really large sky coverage fraction. That's just a choice we had to make.

Ray: You mentioned this cosmic haystack. Could we take a step back and explain what this metaphor of the cosmic haystack is and what are these needles that you're looking for within it?

Shubham: As I said, the cosmic haystack was originally proposed by Jill Tarter sometime in the '80s, I believe. When it was constructed as this "framework" to quantify how much searching has already been done. I believe this was during the time of Project Cyclops, when they wanted to say that, "Okay, the searching that has been done so far, how do we quantify that?" The reason you need something like this is, so you're starting off by looking in the radio and the radio region of the electromagnetic spectrum but you do not know which part of the radio you need to look into, should I look into the high-frequency stuff, the low-frequency stuff? Should I look between one to two gigahertz? The most frequently searched region of the frequency spectrum in the radio has been the 1.4 gigahertz because of the water-hole. People wanted to quantify that, if I'm conducting my search in a particular area, how much of the total fraction can I rule out? That is one parameter that they wanted to rule out. Similarly, in other parameters, how sensitive. Suppose we have a telescope that is hundred meters across versus if you have a telescope that is 300 meters across and they have sensitivities that scale accordingly, so how do you quantify the telescope time. If I'm searching for one hour with a telescope that is hundred meters in diameter versus I'm searching at the same target for one hour with a telescope that is 300 meters in diameter, how do I compare my-- How effective the searches have been? The original framework was proposed to quantify these things and put them all in one cohesive manner. They looked at the number of stars, the frequency in which they were looking at, and I believe also the bandwidth of the searches. That is done to quantify the existing searches and how valuable would the future searches that they were proposing would be. They wanted to say that, "Okay, we've done this so far, but what we are proposing to do will be so much better and build upon this." That is how they started off. Then there have been various versions of this haystack through the years where people have added different parameters and they've adapted it to their searches and their studies to say that, "Okay, this is how our search or how our program compares to the previous explorations." What we are trying to do is take all of these, learn from them, and put them into one cohesive structure. That's what our haystack attempts to do, put everything, combine all these parameters and put them in one framework [crosstalk] Sorry, go ahead.

Ray: No, no, please finish your thought.

Shubham: The last thing is, what are we searching for. What we are searching for, when we construct this haystack, is a radio signal. There's no reason it needs to be just in the radio. It could be in the optical. In fact, we are thinking about making a similar haystack for upcoming optical searches in SETI. We're searching for radio signals, radio pulses that potential extraterrestrial intelligent civilizations would be sending at us. What we're doing is we're searching for these radio-- Most of the haystack that are constructed, including ours, focuses on fairly narrow-band transmission. The original thought was that they'll concentrate all of their energy in this really fine region of the electromagnetic spectrum and put a lot of energy in there so you can detect that across interstellar distances. That's the kind of searches that have traditionally been looked at with these radio searches and they have been quantified using these haystacks, narrow-band radio searches that are periodic, hopefully. It's pretty much agnostic as to the direction in which they're coming from.

Ray: I've heard that radio signals can degrade pretty quickly and that even our radio signals wouldn't reach very far into space. Is that a concern in the SETI search? Is there the thought that maybe, like what are you really looking for in a radio signal? Is there any possibility that they may not even be able to reach our planet in a way that we'd be able to detect them from a civilization that maybe was at the same stage as us?

Shubham: Oh, definitely. There have been tons of people who have thought about this and have put this into numbers. The basic thought is that, suppose I am sitting in New York and you're sending me a radio signal from San Francisco, your power requirement will be much smaller for me to detect than if you were sitting in, say, China, and you were using the same telescope or the same transmitter. If I were sitting in New York, I would need a much bigger telescope or a lot more sensitive telescope to receive your signal from China than from, say, San Francisco. The principle is the same. If I was sending you a signal from Mars and now you're trying to detect it, it would be a lot easier. That's what we're doing with the Mars rovers and the probes we have on Mars. But now if you have the same signal at the edge of the solar system, you will need a lot more power so that I can detect it with the same telescope. So, there are two parts of the problem. One is the transmitter and the other one is the receiver. The bigger the transmitter or the more powerful rather the transmitter is, the easier it is going to be to detect it. On the other hand, if your receiver is bigger and more sensitive, generally bigger helps because the larger the surface area of the telescope, it can make it more sensitive, more light-gathering capacity. Therefore, a bigger telescope is generally better. If you have a sensitive receiver, you can detect signals that are much fainter and potentially therefore that are coming from much further away. That's what we try to quantify in the sensitivity dimension of a haystack. What that says is that if you have a telescope of sensitivity, let's say, X, you will be able to detect fainter signals from much closer away, but as you keep moving further away, you will need to shout a lot louder. To put that in another way, if you're standing on Mars and you're trying to send me a signal using, say, a flashlight, and I have an optical telescope, I will need a much smaller optical telescope than if you were shining the flashlight from, say, Pluto. It's the same principle, but just in the radio. You need to shout a lot louder the further away you are.

Ray: Were you saying you're looking to adapt the framework to work for optical signals as well as radio?

Shubham: We will be constructing the version of this haystack for the optical in the near future. Yes, that is the plan.

Ray: When searching for optical signals, what are we looking for that would identify something as potentially coming from an extraterrestrial race?

Shubham: That is also an intense topic of research as to, say, when you detect a signal in the optical or the radio, how do you classify it as artificial and not natural? Because the last thing any SETI researcher wants is to falsely flag a potential signal as artificial when it's just some weird natural phenomenon. We've seen that happen repeatedly, when we discovered pulsars, we jokingly called them little green men because it was such a strange phenomenon which we hadn't seen in nature before. Likewise now in the recent last 10 years, we've seen stars in the Kepler data, which has this transit light curve that we'd never seen before. People started attributing it to extraterrestrial intelligence and potential forms of super advanced civilization that we do not know about. Now, the scientific consensus is that it's most likely a swarm of dust or comets or something like that. People are very worried as well as cautious about how do you flag these signals and how do you interpret them. For the radio, one possibility is the bandwidth of the signal, how spectrally-broad the signal is. By spectrally-broad I mean, just to give an optical analogy, if I'm shining a laser at you, the laser is quite monochromatic, it just has one wavelength, it has just one color. I'm shining the red laser at you, you're not seeing the entire spectrum of light. You're just seeing a red color. Now, if I'm shining a flashlight at you, that's the white LED, which is emitting from red to the blue, and now, you're seeing the polychromatic source. It's the same analogy in the radio. Most searches have been searching for really narrow-band signals which are extremely difficult or if I'm not mistaken, they're not produced naturally at all. The bandwidth of the signal is one aspect in the radio. Another thing people think about in the radio at least is that maybe the signal will be repeated at specific periods which are not likely to be natural. For example, if I was trying to get your attention, I would try to shine a flashlight, say, for example, not do it periodically but modulate it with some weird frequency. If I turn my flashlight on once every second, it's possible that it's just something far away in the background, which we do not care about, but if I was modulating a flashlight aperiodic or irregular that it's on for three seconds and then off or an even more extreme example would be if I turned it on and off in prime number intervals, then it's a pretty much guaranteed sign that what is producing the signal is not natural but artificial. The period of the signal, the duration of the signal is one way. If that is modulated, that would be a very clear sign of something being artificial. In the optical, this problem is a little simpler in the sense that, there's literally nothing in the optical astronomy universe that is extremely monochromatic and extremely powerful, AKA lasers. You do have lasers and planetary atmospheres that have recently been discovered, but nothing at the same power levels that we're talking about when we consider optical SETI. If there was a civilization that was trying to get your attention in the optical, what we assume for civilization is that it will be based on a planet, next to a host star. That means the host star is also growing in the optical, that's really bright. Now, you're trying to get my attention from a host star next to which is a planet and you're based on that planet, but now you have to outshine the host star so that I'm not seeing the host star but I'm seeing this weird signal that is coming from next to the host star, which I cannot resolve. You basically have to outshine the host star. What we're saying is now you have to produce more energy than the star itself. For a civilization like ours, that is an impossible feat. Kardashev proposed civilizations on his various scales, Kardashev Type 1, Type 2, Type 3, and so on, where you have the energy not only of your host star but of the local cluster of stars and then you have the entire energy of galaxies and so on. Another way to do it is instead of outshining the host star in the entire energy output of the star, you outshine the star in this really narrow wavelength band. What that means is, suppose I was standing next to the sun-- Well, I'm on planet Earth and I'm trying to get the attention of someone far, far away in a neighboring star system. Instead of trying to outshine the sun in the white flashlight region, I'm going to shine this really powerful laser that outshines the sun only in this narrow wavelength region of, say, red. I pick a laser color, and I'm going to make it really, really spectrally pure, so there is no energy that I'm transmitting anywhere else but for this really narrow red region. If I wanted to outshine my star just into this really narrow region of light, then I would require lesser energy, because instead of spreading the energy over the entire optical spectrum from the blue to the red, from the radio to the x-ray, I'm going to concentrate it and shine it just in this really narrow red or blue, or green region of the spectrum. That is one method that has been proposed that people are going to be looking for, to search for these really narrow frequencies or narrow wavelength laser pulses.

Ray: It sounds like these optical signals that we're looking for wouldn't necessarily be something that we're accidentally picking up from another civilization. These would have to be intentional signals that the civilization was sending out in hopes for somebody else to recognize it?

Shubham: That's not entirely true. Of late, we have started using laser transmissions to communicate with our satellites in orbit around the earth, right? We use a laser of a particular frequency, of a particular bandwidth, and of a certain power level. Now, it's possible that you will intercept certain lasers from extraterrestrial intelligence or extraterrestrial civilizations that are accidental, that they weren't intending to transmit to you but they were using for communication that you just happened to intercept. One problem with these searches is that there's literally so much that we do not know. We have to make certain assumptions and build upon them. That is one thing. The only trials we have, the only other civilization that we know of is our own, so we try to assume or we try to base off on how technology has developed for us, and if it was developing in the same manner for another civilization, what would be the potential signatures of that. It is possible that we do detect these accidental transmission signals in the radio or in the laser but the odds of that happening are quite low.

Ray: You mentioned in your paper, there's either a quote or you write yourself about how the search so far has been likened to a cup of water out of the ocean and seeing if we could find a fish in it. I probably misstated a little bit but could you maybe talk to that idea of how our search thus far is pretty microscopic in terms of everything that's out there?

Shubham: Let me give another analogy for this. You are based in San Francisco?

Ray: Yes, that's right.

Shubham: Okay. Suppose I tell you tonight that there is this really cool event happening in San Francisco. If you find that, that will be the best thing in your life and that's going to be this really life-changing thing, but I don't tell you where in San Francisco it's happening, I do not tell you what time it's happening, I don't tell you if it's tonight, if it's next month, if it's next year, I can't even tell you if it's already happened, but there is this event that might happen there that if you were to find, it would be amazing. I do not tell you what it is. I don't tell you if it's a book reading or if it's a dance competition or if it's your favorite band playing. I'm giving you absolutely no information. Now, I'm going to tell you that if you find it, it'll be amazing and really cool. Now, you have to think about, "If I want to find this thing, how can I go about narrowing it down?" So, you would probably play the odds and say, "Maybe it's not going to be in the middle of the busiest intersection in San Francisco. It's probably not going to be at noon, so I will go to a music concert venue and see if there's something there at 07:00 in the evening on a Saturday because you know that if it's music-related, it's going to be over here. If it's not there, maybe I'll try a library or a bookstore and see if it's a book reading or something." So, you'll systematically start narrowing down and eliminating your possibilities. Now, what happens, suppose after two days of searching, you say that, "I have looked into these places, and I've ruled these out." That is what we're trying to do. In the last 40 years or so that we have been looking, we have tried to quantify that out of the total possibilities, how many have we ruled out? The reason the total number of possibilities exist are so broad and so unconstrained is because we didn't want to make any assumptions and narrow them down. We wanted to be as agnostic and as wholesome as possible in the sense that we did not want to assume that, "Oh, they will be transmitting from stars, not from empty space. They will be transmitting only in this region of the wavelength band or they'll be transmitting only from one second to one hour, not anything beyond one hour." So, we did not want to make any such assumptions. In the most conservative scheme possible, we say that this is the total amount you need to search. Now, suppose I told you San Francisco, if I didn't even tell you that, if I said there's something really cool happening on earth, how long will it take for you to search for that? I do not tell you the time, I do not tell you the place, what it is, et cetera. I believe it's one bathtub of water in the entire ocean. The implicit message behind that is before we say, "We've been looking for the last 40 years--" because that's what many people say that we've been looking for the last 40 years and we haven't found anything. The truth is the amount we've actually looked in this gigantic framework is so small, we can't really say we've ruled anything out. We can't say we placed any upper limits on the broader picture. There have been searches which have looked at the stars, and okay, you can say that this star or this stellar system, we do not see anything that is being transmitted in this wavelength region at this time for the five minutes that we looked. That's the only constraint you can place, but you cannot say anything about that it doesn't exist, a civilization, on that stuff, let alone the entire galaxy or the fraction of the galaxy that you looked at because the fraction you've looked at it's so damn small.

Ray: Do you worry that there's maybe any negative repercussions to framing the search as vast and as hard to identify any signals like this? Do you think that's a turnoff to any researchers to even enter the field because it is just so daunting?

Shubham: The number that we placed is more of a qualitative estimate to show that how little we've looked. The quantitative aspect of the framework is to compare different searches that, "Okay, this search has done this, while the other one, which had a different goal in mind, this is how it stacks up." That's how you can compare it. The number itself is not to say that, "Okay, if we have put in this much effort in the last 10 years, we need to scale it up by a factor of 10 billion to find something." That's not what the message behind the number is, that you need to put in 10 to the power 18 more units of effort to find something. It's just to show that this funny paradox that we're talking about, that we've looked and looked and looked for the last 40 or 50 years and we haven't found anything is not really true because we haven't really looked that much. Before we make any statements, any such bold statements that we've been looking, and we haven't found anything, we should take a step back and think about how much have we actually been searching and how much effort has been really put into it and how much more should we put into it.

Ray: You mentioned the Fermi paradox. That's actually the topic of our episode. Could you explain in your own words your understanding of what Fermi paradox is?

Shubham: I think the best way to capture the Fermi paradox is this XKCD comic that I can send you. What it-- Let me just pull it up.

Ray: Definitely. Yes. Please send it. Send it all into my email if you can.

Shubham: It's basically XKCD comic number 638, and I can send it to you.

Ray: Right. [silence]

Shubham: You can let me know once you get it.

Ray: Just checking now. Yes. There we go. Let's see. Okay. Yes. I have it open.

Shubham: As you can see, I think that's one frame basically captures the essence of the Fermi paradox.

Ray: Could you maybe just because this is going to be audio only, and I can definitely link to this in our show notes, but could you maybe just kind of describe what is happening in this image and kind of like what the idea behind it is?

Shubham: Oh, sure. The basic essence of the Fermi paradox is that we have been looking for so long, and we haven't found anything. If we say that life should be everywhere and that the mechanism of formation of life should be fairly ubiquitous. Then considering the number of stars in the galaxy, even if the odds are small, the universe should be teeming with life. Then the second point is, considering the age of the galaxy, life that has evolved, even say a tiny fraction of that age before us and a tiny fraction of billions of years is millions of years, thousands of years before us, they would have evolved to a stage that they would now be colonizing different stars and different stellar systems and traveling across the galaxy. If that is so, the whole galaxy that we observe should be teaming with life. Since we do not see that, life probably doesn't exist, extraterrestrial life doesn't exist.

Ray: Great. Thank you. Could you maybe talk about some of the current technological and also societal limitations for our civilization to be able to search for extraterrestrial civilizations? What are some of the obstacles we currently face?

Shubham: I think some of the obstacles we face are technology in terms of, we still use rocket fuel for traveling across the solar system. Something like that is not a feasible option when you want to travel interstellar distances. There have been recent projects and studies looking into, what if we can use photon energy itself or light from the sun to propel you at the light speed. Then there have been searches or there have been projects which are looking into using nuclear-propelled rocket engines and different technologies like that, which would make it a lot more, I wouldn't say easier but technically feasible to move across interstellar distances. The main challenge is the technology and that is because of the distances involved. We're talking about the closest star, it's four light years away, and each light year is about one followed by 16 meters. We're talking about numbers which are extremely hard to fathom and because of the distances involved, I don't think we have still reached the point that we can say, "Send a human across interstellar distances." We are still-- We're not sure that we can send a human to Mars, which is right next door compared to the stars that we're talking about. We just don't have the technology in the context of propulsion, in the context of healthcare. All the political-- The backing to spend that kind of money to develop the technology because right now, I guess the powers that we do not see the advantage in that.

Ray: Do you have any future projects planned in the study space?

Shubham: As I said, one thing that we're thinking about is the optical haystack, which is similar to what we've done, but in the optical region of the electromagnetic spectrum. Another thing that we're thinking of at Penn State as part of my graduate work, I'm also working on building these two spectrographs called the habitable zone planet finder. The second one is NEID and these are radial velocity spectrographs which will search for earth-like planets or planets which have the potential to have liquid water, they're in the Goldilocks zone of their stars. The spectrographs will do this using the technique called radial velocity, which basically takes the light from the star and splits it into thousands and thousands of colors, and then sees how those colors move around. Now, a by-product of doing this is you have what is called a really high resolution spectrum of the stars. You're taking the light from the stars, and as I said, splitting into thousands of colors. What you can do is once you have this, you have a really nice map of the star. If suddenly in this map, you see one of the colors or one of the lines become really bright, which is exactly what I was talking about earlier when I was referring to the optical signals that could potentially be sent. You could outshine your star not as a whole but in the narrow wavelength region. We're planning to use these spectrographs with the data that is already there, so we don't need to conduct more searches and spend more money to build new instruments. We just need to look at existing data and comb through it if we see any such peaks jumping out.

Ray: You mentioned in your paper, you talk about this concept of the great silence or the eerie silence. Could you give a little context into what those terms mean within the context of searching for extraterrestrial life?

Shubham: Great silence. I think that was something that Jason delved into and I'm not the best person to speak too much about that. For the eerie silence, there's this book chapter by Paul Davies that covers it really well.

Ray: I know there's been a few signals that have been detected that have caused excitement, that have been disproven usually in the end. Are there any signals that have been detected thus far that still remain mysterious and possibly could be extraterrestrial in origin?

Shubham: I think the only signal that I know of that had been detected and is still mysterious is the Wow! signal that was detected I think in the 1970s by the radio telescope called the Big Ear which was I think built by Ohio State or managed by Ohio State. It was this really powerful signal. It was I think 20 sigma. Many, many thousands of times more powerful than that background, stronger than the background. They detected it for a few moments and then it was never seen again. I think there have been many hours of radio telescope looking at that patch of the sky, but they haven't found anything. That is the only signal that I can talk about.

Ray: That was a radio burst?

Shubham: That was a radio signal, yes. I wouldn't call it a radio burst because we've recently discovered a radio phenomenon called fast radio burst which is an astronomical phenomenon associated with certain events. I wouldn't necessarily conflate the two because there hasn't been any study that I know of that associates the Wow! signal with a radio burst.

Ray: Interesting. If any of our listeners were interested in helping to get involved in the search for extraterrestrial life, are there any contributions that people can make to help further this research?

Shubham: Yes. As I was saying, there have been searches done over the last 40 years. There has been great work done by the SETI Institute and recently is the Breakthrough initiative. What the SETI Institute has is this thing called SETI@home. One issue with the searches is they're getting too much data. The amount of computing power needed to analyze it is simply quite limiting and quite a restricting factor. What the SETI Institute has done is they have crowdsourced data analysis. What you can do is you can download this software called SETI@home on your personal computer. Then whenever your computer goes to sleep or goes on to screensaver mode, instead of the computing resources lying vacant, what it will do is it will download some data from the Internet, from radio searches for such signals and silently run it on your computer and analyze it. Then when your computer turns back on, it can show you what searching it has done and the amount of data it has looked at. Then it will send it back to the servers and add it to the giant collection of data that they've already gone through to make certain predictions or analysis to say that, "Okay. This is the searching we've done. This part of the sky we've looked at, now let's look at this part of the sky" and so on. The SETI@home is one of the best ways that I know that can be helped with. Anyone can do it. Even I can-- We can just download the software on a computer. It's available on the Internet, SETI@home. It just works in the background. You don't need to do anything, and it works pretty well.

Ray: That's awesome. Do you have any last thoughts or comments that we haven't touched on?

Shubham: I think I can just end by saying that there are many people who have been working on this and also devoted a big fraction of their life on this, on this search for extraterrestrial intelligence. I think the prime example is Jill Tarter who has been deeply trailblazing and who has pioneered so many things that we are now working on. People often say that, as I said, we've been looking for so long. These people have done so much work, haven't you still found anything? I think what we need to understand is the amount of work that is needed and the number of people who are working do not match. These people have put in so much time, but we need a lot more effort and funding to make an appreciable dent in this field. The best part is that these searches are not in a different field from astronomy. We are looking at the same sky using similar instruments. One amazing thing that is happening now in astronomy is we are building these gigantic telescopes and conducting these surveys of the entire sky. In the optical, you have the LSST coming up in Chile, which is an NSF-funded project, that is going to get terabytes of data every night. In the radio, you have this Square Kilometre Array coming up in the southern hemisphere, which is going to be this gigantic radio telescope that will generate petabytes of data. What SETI needs as a field now is not money to build its own telescopes, but there are already so many existing wonderful telescopes that are existing or are coming up in the next few years, that it needs the people power and the computing power to go through this existing data and crunch it, make some analysis and crunch numbers to make some conclusions as to what fraction of the sky that we have now ruled out. I'm talking about these gigantic searches because they're going to look at the entire sky day in and day out. Those are the kind of searches that will make a big dent in these numbers. These numbers which look so daunting right now, a telescope like LSST or the Square Kilometre Array in the southern hemisphere, they will make mincemeat out of many of these numbers.

Ray: That's great. Well, that's all the questions I have for you. Thank you so much for taking the time to do this. This was really awesome. I've been interested in SETI since I was a small kid. I remember getting one of my books signed by Seth Shostak when I was a little kid.

Shubham: I see.

Ray: It's really cool to be able to be talking to people involved in the search right now for this episode.