Does it make sense to build new radio telescopes?

[Line_112]

TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better?

In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. At the same time, this probability, given the previous experience of building increasingly powerful radio telescopes, purely according to probability theory, is not small. Is there any sense in this or is blissful ignorance better? Moreover, in the version of the Matrix world, there may not be any aliens at all. In addition, the existing telescopes can please us with an unexpected discovery of a signal at any moment.

The study of all sorts of pulsars and other such things is a rather stupid undertaking. They do not affect our salaries and pensions in any way, and since they are considered natural objects, there is even less sense in studying them. They pulsate and pulsate, and we are neither cold nor hot from this. They do not affect our understanding of the structure of the Universe. Building an expensive telescope for the sake of yet another test, or rather, imitation of confirmation, of the General Relativity is not something that can inspire. I am sure that I express the opinion of the majority of people.

So, if the decision to build and launch a new telescope depended on me, I would not support it. What do you think about this?

 

[Baluncore]

So, if the decision to build and launch a new telescope depended on me, I would not support it. What do you think about this?

I think it is lucky for RA that it is not your call. Radio astronomers will apply for grants, and some will receive resources to fund their research. Are you going to veto that research?

Arrays of radio telescopes can now make a big difference, because we have the fibre communications bandwidth and correlators capable of synthesising the new images. That headlong rush of advances in data processing and bandwidth, is yielding new results.

An array is made from many individual apertures and receivers. Without active research, the development of new receivers, that might advance the arrays up another step, to the next generation, would stop.

 

[Frabjous]

What should be funded and at what levels is a very complicated question.

Almost no basic science would be performed using the metric of impact to salaries and pensions. Since yesterday’s basic science is the source of today’s new technologies, this metric has issues.

The SKA was proposed in the early 1990’s and construction didn’t begin until 2018. To assume that there will be an automatic successor is naive.

 

[fresh_42]

The German Wikipedia page lists five big scientific goals. I wouldn't call that negligible. We are a species that is curious and strives to understand the world we inhabit. You cannot change this; it is what we are. Almost none of the modern scientific projects recoup their investments. I doubt that even the satellites that enable this discussion ever did, if you include the total amount of costs since 1960. If we always made our decisions by ROI, we would still be carving stones, and you wouldn't have a pension fund.

Even Columbus had difficulties financing his journey. Whether he had better stayed at home is an interesting, though fruitless discussion.

 

[PeterDonis]

The study of all sorts of pulsars and other such things is a rather stupid undertaking.

So you think advancing science is stupid?

They do not affect our salaries and pensions in any way

Neither does understanding "the structure of the Universe", or indeed much scientific research in general. At least, not that you can see. But that's the whole point--you don't know how advancing science is going to affect ordinary everyday things until you do it. Your attitude would have had us not bothering to study General Relativity or quantum mechanics because it had no impact on everyday lives--which would mean we wouldn't have computers or GPS today, which have had a huge impact on everyday lives.

since they are considered natural objects, there is even less sense in studying them.

Huh? Why doesn't it make sense to study "natural objects"? I don't get this at all. The vast majority of things in the Universe are "natural objects" (assuming that by that you mean basically "not made by humans"). Should we not bother studying any of them?

They do not affect our understanding of the structure of the Universe.

I'm not sure why you think understanding "the structure of the Universe" is somehow a more valuable undertaking than studying pulsars. Science is all one thing. If you're going to study science, to push the frontiers of our knowledge, you want to do it everywhere you can, because it all interacts.

Building an expensive telescope for the sake of yet another test, or rather, imitation of confirmation, of the General Relativity is not something that can inspire.

Maybe it doesn't inspire you, but it certainly seems to inspire a lot of people that work in the field. Maybe that's why they're doing that, and you're not.

I am sure that I express the opinion of the majority of people.

Based on what? How many other people's opinions have you gotten?

 

[Cerenkov]

One might well ask, does it make any sense to build new optical telescopes like the EELT?

Or new space-based telescopes like the JWST?

Or new gravitational detectors like LIGO, KAGRA and Virgo?

Or new neutrino telescopes like Hyper-Kamiokande and IceCube?

Or new particle accelerators like the Large Hadron Collider?

My salary and pension will not be affected by any discoveries they'll make.

So, yes, let's not bother building any new instruments that will tell us more about the universe.

Let's just climb into a hole in the ground, stick our fingers in our ears and go "La-La-La!"

 

[Borek]

Assuming someone decided "we don't need any confirmation of GR, why should we research such a natural, completely useless phenomena" back at the beginning of the XX century, we would have no reliable GPS system, which millions of drivers use to navigate and earn more by not getting lost.

So you never know.

 

[robphy]

https://public.nrao.edu/radio-astronomy/the-science-of-radio-astronomy/

How radio telescopes show us unseen galaxies | Natasha Hurley-Walker (TED)


'People didn’t believe it was possible': Dr Terry Percival

Terry Percival is an Australian research scientist and research engineer. He worked at CSIRO as part of the team that invented wi-fi technologies.
In the 1990s the team set out to develop a high-speed communication system which would enable portable devices such as phones and laptop computers to connect wirelessly to the internet at very high speeds.
At the time, many people didn’t believe this was possible. However, the team drew upon their vast experience in radio astronomy and satellite communications to solve the problem. Their passion and perseverance was rewarded when they won the European Inventors Award in 2012.
This story is featured in National Archives’ exhibition Disrupt, persist, invent: Australians in an ever-changing world.

(bolding mine)


https://public.nrao.edu/news/from-cells-to-galaxies-and-beyond/

From Cells To Galaxies And Beyond
Scientists in radio astronomy and medical imaging find common ground

Neb Duric, Introductory Overview - From Cells to Galaxies: Imaging Challenges in Astronomy & Medicine

While radio astronomy and medical radiology occupy opposite ends of the imaging scale, they share some remarkable similarities. First, both rely on the detection and processing of digitized (raw) signals. Secondly, both use complex reconstruction algorithms to form images. Thirdly, the systems studied in radio astronomy and medicine are of comparable size when measured in terms of resolving power (beam width). Finally, both disciplines face similar challenges with computational costs, management of large data sets and the need for automated image interpretation. Despite these similarities, the evolution of imaging science in the two disciplines has proceeded on separate, non-intersecting paths. Thus, the respective innovations in imaging have remained largely separated. The purpose of this presentation is to provide an overview of the similarities and differences in imaging methods in order to kick off the meeting whose goal is to identify challenges and opportunities for collaborations between astronomers and medical imagers. The ultimate goal of this meeting is to (i) expose innovations across the two disciplines, (ii) identify areas of overlap and (iii) put into motion practical applications that can further advance each field through the formation of inter-disciplinary collaborative groups.
Video created 09/15/2021

 

[Line_112]

I don't get this at all. The vast majority of things in the Universe are "natural objects" (assuming that by that you mean basically "not made by humans").

I meant created by alien civilizations. Not humans, of course.

 

[Line_112]

So you think advancing science is stupid?

I haven't written about science in general, but there are areas that are either unproductive or have negative side effects. For example, in the case of AI development, this is the loss of income sources for many people (I am one of the victims) and the cluttering of the Internet with stylized low-quality information (AI responses in Google and other search engines are wretched). In the case of attempts to detect alien signals (I am concerned about this issue), scientists have not yet found a single signal that, in their opinion, would definitely have an artificial alien nature. The negative effect is that after such results, suspicions arise about the imminent death of humanity (the rapid death of civilizations is one of the main hypotheses explaining the radio silence of the Universe). But why spoil people's mood when there are enough reasons suspect doom, such as accelerating climate change on the planet? Therefore, I am negative about expanding the scale of such research, given its fruitless (and therefore negative in terms of impact on society) results. When (or if) we have the ability to colonize exoplanets, then they may become practically significant directly for the implementation of such projects. But this will not be soon, at the very least.

 

[Cerenkov]

I meant created by alien civilizations. Not humans, of course.

Provided that we keep on building bigger and better radio telescopes, it's a win - win scenario, Line_112.

If they detect no other intelligent life then that will tell us that it is either very rare or absent. Knowing that we can better understand our place in the universe.

Or, if a signal is detected, then we will know that we aren't alone. If two technological civilizations can arise at about the same time in relatively close proximity in our galaxy that points to the universe being more life-friendly than we first thought. This knowledge will change everything about how humans view themselves.

Either way we win because we learn more than if we did nothing.

But if we didn't build such telescopes we would never know which it is. We would remain in ignorance. That's what happens when we put salaries and pensions before all else. When, if it doesn't directly affect how we live our daily lives, we ignore it. Ignoring leads to ignorance.


So, perhaps something written by Albert Einstein is appropriate here?

He who can no longer pause to wonder and stand rapt in awe, is as good as dead; his eyes are closed.

Albert Einstein (2013). “Einstein on Politics: His Private Thoughts and Public Stands on Nationalism, Zionism, War, Peace, and the Bomb”, p.229, Princeton University Press


Do you ever pause to wonder and stand rapt in awe, @Line_112?

 

[PeterDonis]

I meant created by alien civilizations. Not humans, of course.

Oh, so you think it's only worth studying objects if they were created by alien civilizations? That doesn't make sense to me. Particularly since we haven't found any such objects.

 

[PeterDonis]

there are areas that are either unproductive or have negative side effects. For example, in the case of AI development

That's not science. That's technology. As far as I can tell, it doesn't even depend on any discoveries at or near the frontier of science, just the continuing advance in available digital computing power, which has been going on for decades.

 

[PeterDonis]

attempts to detect alien signals (I am concerned about this issue), scientists have not yet found a single signal that, in their opinion, would definitely have an artificial alien nature.

That's true.

The negative effect is that after such results, suspicions arise about the imminent death of humanity (the rapid death of civilizations is one of the main hypotheses explaining the radio silence of the Universe).

This at least makes it a bit clearer what you're concerned about. But first, this is just one particular area of science, and a very small part of science as a whole. So it makes no sense to be saying we ought not to study, for example, pulsars for this reason.

And second, science is the search for truth. If the truth is that we are the only civilization in the universe, and that we are facing a high existential risk because the reason we're the only one now is that civilizations rapidly destroy themselves once they reach a certain point, then knowing those things at least gives us a chance to change the outcome. But if we just go on in blissful ignorance and don't investigate these things, we have no chance of changing the outcome.

 

[Cerenkov]

Ok, this isn't about radio telescopes per se, but it's about the 'why bother about space if it doesn't affect us' attitude.

In 2013 the Russian city of Chelyabinsk got lucky when an incoming meteor caused a 400/500 kiloton airburst overhead. Nobody was killed. There were some injuries and a lot of property damage. Since the Hiroshima bomb was rated at about 16 kilotons and caused around 100,000 deaths, can you imagine the devastation and casualty figures if Chelyabinsk's luck had run out?

Some day another city's luck will run out. Maybe you will be there. Or maybe an entire continent will suffer a catastrophic strike from above. It's not a case of IF, it's a case of WHEN. These massive impacts have happened throughout Earth's history and they will continue to do so.

So, is the best policy to keep our eyes firmly downwards on our pay packets and bank balances?

Or would it be prudent to spend the money wisely and find out where and when we will be hit?

Then, knowing what is coming our way in advance we can do something about it. Either try and deflect the object or at least evacuate the target area and minimise casualties as best we can. But to do nothing makes us the victims of events and forces that we knew nothing about. It would be already too late by the time the impactor enters our atmosphere. We will have died because of our ignorance.

Fortunately for us (and you) there are those who don't think as you do, Line_112. Those who are actively seeking to expand our knowledge of these threats. Those who have spent the money trying to stop people dying in ignorance and of ignorance.

Like it or not, what goes on in the depths of space DOES affect you.

 

[Line_112]

And second, science is the search for truth. If the truth is that we are the only civilization in the universe, and that we are facing a high existential risk because the reason we're the only one now is that civilizations rapidly destroy themselves once they reach a certain point, then knowing those things at least gives us a chance to change the outcome.

Probably, advanced civilizations do not use radio communication. Then there will be a false idea of our loneliness, from which there will be nothing but harm. There are more promising ways to detect biological activity on exoplanets than trying to catch a radio signal, which may not exist. It seems to me that then it is better to invest in astrobiology, instead of fruitless attempts to catch a signal. And the outcome will change when the rich give up excessive consumption, and it does not depend on this in any way from detection or non-detection of signals, otherwise it would have already worked.

 

[PeterDonis]

Probably, advanced civilizations do not use radio communication.

They might not once they reach a certain point of advancement. But they still had to reach that point. And in doing so, judging by our experience, they almost certainly emitted lots of radio waves that would carry clear indications of intelligent origin--just as the ones we've been emitting for more than a century now do.

There are more promising ways to detect biological activity on exoplanets than trying to catch a radio signal

What ways are these? Please give references.

It seems to me that then it is better to invest in astrobiology

Then go ahead and invest in it. Nothing's stopping you from starting your own astrobiology research center.

the outcome will change when the rich give up excessive consumption

Whatever this is, it's not about the thread topic.

 

[Line_112]

And in doing so, judging by our experience, they almost certainly emitted lots of radio waves that would carry clear indications of intelligent origin--just as the ones we've been emitting for more than a century now do.

But if this is a short period by astronomical standards, then there will be very few such civilizations, perhaps one in the entire galaxy.

What ways are these? Please give references.

Direct photography of planets (in the future), search for bioindicators.

 

[PeterDonis]

if this is a short period by astronomical standards, then there will be very few such civilizations, perhaps one in the entire galaxy.

At the present time, yes. But there could be lots of radio waves from previous ones. And the area of search isn't just our galaxy. It's the entire observable universe. Of course radio waves from other galaxies get harder to detect the further away the source is, but that's just a matter of increasing detection sensitivity, which will continue to happen over time.

Direct photography of planets (in the future), search for bioindicators.

Sure, if at some point we have optical telescopes that are that good. But that's not something we'd do instead of radio astronomy. It's something we'd do in addition to radio astronomy. Just as we're doing now. IIRC we already have fuzzy optical images of possible exoplanets--of course not with any kind of resolution that would allow us to search for bioindicators, but again, that's just a matter of increasing detection sensitivity, which will continue to happen over time.

However, I'm still confused about your position. You say that finding out that we're most likely alone in the universe has had a negative impact. Wouldn't getting even more evidence of that, by direct photography of exoplanets, searching for bioindicators, and not finding any, have even more of a negative impact, if your viewpoint is correct?

 

[Line_112]

At the present time, yes. But there could be lots of radio waves from previous ones. And the area of search isn't just our galaxy. It's the entire observable universe. Of course radio waves from other galaxies get harder to detect the further away the source is, but that's just a matter of increasing detection sensitivity, which will continue to happen over time.

If on average there is one radio-emitting civilization in the entire galaxy, then on average, waves will only reach us from one (there may be more, or there may not be any at all, it's a matter of luck). Now waves from one can reach us, after some time - from another, but not simultaneously from all, since they emitted at different times. In the neighboring galaxy (and in ours at a great distance, I think too) we are unlikely to detect anything sensible, firstly because of the strong distortion of radio waves by the interstellar/intergalactic medium (there will be banal radio bursts, which we are recording the fact), secondly, because of natural radio noise, and thirdly, because of the extreme weakness of such signals. They won't build 10-kilometer dishes or build up half a continent with connected radio telescopes of a smaller size. Proponents of the search, in order to get funding, will claim that it is possible to "pick out" signals from noise and that the limit of detectability has not yet been reached. But whether this is actually true, and if so, to what extent, is a big question.

 

[Line_112]

However, I'm still confused about your position. You say that finding out that we're most likely alone in the universe has had a negative impact. Wouldn't getting even more evidence of that, by direct photography of exoplanets, searching for bioindicators, and not finding any, have even more of a negative impact, if your viewpoint is correct?

It will be more gradual and less clear-cut, and will take many decades. By that time, the climate change and nuclear threat may already be solved, and therefore it will not be so scary to get negative results (although I hope they will be positive). And if they are not solved, then civilization will be destroyed before this happens, and after death the problem of fear and loneliness will not be relevant.

 

[Cerenkov]

If on average there is one radio-emitting civilization in the entire galaxy, then on average, waves will only reach us from one (there may be more, or there may not be any at all, it's a matter of luck). Now waves from one can reach us, after some time - from another, but not simultaneously from all, since they emitted at different times. In the neighboring galaxy (and in ours at a great distance, I think too) we are unlikely to detect anything sensible, firstly because of the strong distortion of radio waves by the interstellar/intergalactic medium (there will be banal radio bursts, which we are recording the fact), secondly, because of natural radio noise, and thirdly, because of the extreme weakness of such signals. They won't build 10-kilometer dishes or build up half a continent with connected radio telescopes of a smaller size. Proponents of the search, in order to get funding, will claim that it is possible to "pick out" signals from noise and that the limit of detectability has not yet been reached. But whether this is actually true, and if so, to what extent, is a big question.

Why would you predicate your argument on such an average? Could you please explain your reasoning and how you arrive at the conclusion of there being (on average) no more than one radio-emitting civilization in the Milky Way.

Could you then explain your reasoning for applying that average to other galaxies, seeing that most of the members of the Local Group, besides M31 and M33, are not spiral galaxies.

Please cite a source for your claim that the ISM/IGM strongly distort radio waves.

Also, please explain what you mean by banal radio bursts.

 

[fresh_42]

I got the impression that you think radio astronomy is meant to listen to alien radio shows. This is not even close to what it is meant to be. We can primarily detect EM waves besides neutrinos and gravitational waves. Hence, astronomers aim to cover the detectable spectrum of EM waves as comprehensively as possible, allowing them to observe as much as possible. Radio signals are one part of this spectrum, and possible sources for such signals are not radio shows from aliens.

 

[Bandersnatch]

While the SKA does list search for alien signals as one of its projects, I'd wager my hat on it being there mainly as a media angle. It is a radio telescope, it's going to be used for radio astronomy.

 

[PeterDonis]

They won't build 10-kilometer dishes or build up half a continent with connected radio telescopes of a smaller size.

Why not? There's nothing impossible about it. Sure, it's not going to happen tomorrow. But what about a hundred years from now? Or a thousand? Or more? A hundred years ago radio astronomy didn't even exist. Now it is where it is. What makes you think it can't progress that much further?

Proponents of the search, in order to get funding, will claim that it is possible to "pick out" signals from noise and that the limit of detectability has not yet been reached. But whether this is actually true, and if so, to what extent, is a big question.

Sure. And radio astronomers propose to test it by building more and more capable instruments and seeing what they detect. And there are lots of possible things to detect besides looking for signals from other intelligent life, which can be used to test whether increased sensitivity really is gained as predicted. Nobody is advocating for building more powerful radio telescopes solely to search for radio signals from other intelligent life. That search is a side effect of the existence of radio telescopes that were built to look for many other things, in order to expand our scientific knowledge of the universe in general.

 

[PeterDonis]

It will be more gradual and less clear-cut, and will take many decades.

It was gradual and not very clear-cut and took many decades to get to the position we're in now. It didn't happen overnight and it wasn't sudden. So I still don't understand your position.

 

[Line_112]

What makes you think it can't progress that much further?

It seems to me that this will be too expensive and will require a lot of resources, and possibly territories.

 

[Line_112]

Also, please explain what you mean by banal radio bursts.

Fast radio bursts, for example.

 

[PeterDonis]

It seems to me that this will be too expensive and will require a lot of resources, and possibly territories.

Not if they're built in space. Which is the obvious next step, just as it was with optical telescopes.

 

[Line_112]

Not if they're built in space. Which is the obvious next step, just as it was with optical telescopes.

I read that there are ideas to build a radio telescope on the far side of the Moon. There will be no anthropogenic noise there.

 

[PeterDonis]

I read that there are ideas to build a radio telescope on the far side of the Moon. There will be no anthropogenic noise there.

Yes, that would be another logical step. But you seemed to be skeptical that radio astronomy would continue to advance--but now you're saying it will. Which is it?

 

[fresh_42]

Yes, that would be another logical step. But you seemed to be skeptical that radio astronomy would continue to advance--but now you're saying it will. Which is it?

Someone should have informed the Chinese before they built the world's largest radio telescope and spent half a billion dollars on relocations and construction. And I bet it is as overbooked as any telescope we have.

 

[Cerenkov]

Replying to the questions put to you doesn't seem to be your forte, does it Line_112?

I put four to you and you respond to just one. A success rate of just 25%.


Why would you predicate your argument on such an average? Could you please explain your reasoning and how you arrive at the conclusion of there being (on average) no more than one radio-emitting civilization in the Milky Way.

Could you then explain your reasoning for applying that average to other galaxies, seeing that most of the members of the Local Group, besides M31 and M33, are not spiral galaxies.

Please cite a source for your claim that the ISM/IGM strongly distort radio waves.

Also, please explain what you mean by banal radio bursts.


So now everyone here knows what you meant by banal radio bursts. FRB's.

But we are all still in the dark as why you think there is on average just one radio-emitting civilization per galaxy. What kind of average is this? Mean, mode or median ? And an average of what exactly?

Nor do we know, out of the galaxies of the Local Group which you consider as viable hosts for intelligent life. Spiral, elliptical, irregular or dwarf? They are not all the same. Therefore, when you talk of a neighbouring galaxy we have no idea which galaxy in the Local Group you mean and why.

Lastly, your claim that the ISM/IGM strongly distorts radio waves remains unsupported. No source cited, no link given, nothing.

I'm not a dentist, but getting answers out of you is like pulling teeth.

Please rectify this.


Cerenkov.

 

[Line_112]

Yes, that would be another logical step. But you seemed to be skeptical that radio astronomy would continue to advance--but now you're saying it will. Which is it?

Rather, to increasing the power of telescopes than to change their location. On Earth, is greatly hampered by terrestrial interference, and it is always very unpleasant when a suspicious signal is first reported, and then official scientists refute it. A telescope on the far side of the Moon would reduce the number of such tricky cases, and the probability that the caught suspicious signal is connected precisely with an alien civilization would be much higher. As well as the probability of detecting such signals (the less noise, the lower the risk of missing or misinterpret). So there really are reasons for such a format of searches.

 

[fresh_42]

If you were right, then why are the observation times on our existing telescopes notoriously overbooked?

Preliminary results after closing the Cycle 10 Call for Proposals (CfP) shows continued strong demand for ALMA time. The community submitted 1680 proposals. Although this is a slight decrease from the most recent cycles, the amount of time requested on the 12-m array increased to over 29,000 hours, which is the most time ever requested in a single cycle. This implies an overall oversubscription rate of 6.9 on the 12-meter array. The amount of time requested on the 7-m and Total Power arrays also remains very robust, with approximately 15,000 hours requested on each array.

Source: ALMA

Certainly not for searching for aliens. I strongly agree with @Bandersnatch (post #24) that the alien civilization aspect is mainly a bait for the public to get interested in the subject. I dare to claim that you wouldn't be granted any observation time on any existing radio telescope if the goal of your project were to detect aliens.

 

[Jaime Rudas]

I think it is lucky for RA that it is not your call.

Yes, but it is still worrying that more and more people responsible for this type of decisions think the same nowadays.

 

[Herman Trivilino]

They do not affect our salaries and pensions in any way, and since they are considered natural objects, there is even less sense in studying them.

Basic research is founded on the basis of advancing knowledge, not with necessarily achieving a particular goal. History has taught us that societies that employ this attitude advance technologically, and those that don't stagnate or fail. This is because advances in knowledge often lead to unanticipated advances in technology.

 

[Jaime Rudas]

it is always very unpleasant when a suspicious signal is first reported, and then official scientists refute it.

Yes, those official scientists always try to refute everything.

 

[Herman Trivilino]

Yes, those official scientists always try to refute everything.

There's no such thing as an official scientist.

Scientists put forth new theories and experiments. They don't always try to refute everything. They do try to refute some things. Sometimes they are successful and things get refuted. Sometimes they are unsuccessful and things get advanced. This is a centuries-old process that advances society. Without it, for example, this platform for our discussions would not exist.

 

[Jaime Rudas]

There's no such thing as an official scientist.

Yes, maybe I didn't clarify that this was a sarcastic response.