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I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the poten

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline right now is one with a 30 metre mirror. This telescope won't be big enough, and as a result, our failure to push now for bigger sizes is almost certainly going to push back for decades humanity's ability to answer one of the most important questions we face: Why are we here, and are we alone.

saganus 9y ago
Isn't building a 100m telescope incredibly hard? does that kind of technology exist already? (I genuinely don't know). Also, what would the effect of the atmosphere be in such a large telescope? would a bigger mirror increase or decrease the effects of Earth's atmosphere for these kind of observations?
- Balgair 9y ago
  Noise is noise. If you put gain on the signal in general, you'll put gain on the noise too. That's why James Webb is in space and the 30 Meter Telescope (TMT) is in Hawaii, less atmosphere and clear air means less noise inputted. Still, the TMT is pretty darn good. So yes, you are correct, bigger telescope means more noise (in gestalt) while in atmosphere. THe reason bigger is better is because you can resolve smaller angles. The Fourier treatment of optics is useful here. The radius of your lenses/reflectors sets the limit of the higher spatial frequency. Low spatial frequencies pass through small lenses/refectors and high spatial frequencies pass through larger ones. Therefore the bigger the telescope, the more higher order spatial frequencies you can collect. https://en.wikipedia.org/wiki/Fourier_optics https://en.wikipedia.org/wiki/Fourier_optics Why not a 100 Meter Telescope? Cost and engineering. With these retro reflectors getting so big, you have to worry a lot about thermal expansion and differential levels of it across the whole surface. Also, the structure to hold it has to be monitored really closely in real time to make sure the calculations are accurate. It's not easy. Also, with modern adaptive optics, you'll have apply all the little piezo-motors across the entire surface which goes as the square of the radius, so costs go up geometrically (plus about 15% more for each doubling in surface area due to cabling, power issues, larger facilities with thicker steel beams, more janitors, etc.). If the TMT costs X, then the 100-MT should cost about 11X, and with the 15% doubling factor, its ~15X for only a 3X increase in radius.
  - ExactoKnight 9y ago
    > If the TMT costs X, then the 100-MT should cost about 11X, and with the 15% doubling factor, its ~15X for only a 3X increase in radius. The Thirty Meter Telescope cost $1 billion. So the 100 Metre Overwhelmingly Large Telescope would cost ~$15 billion using your ~15x multiplier. That's large, but for perspective: The F-35 fighter jet program cost $168 billion. Like with the Large Hadron Collider, if the extra cost means the difference between being able to crucially measure the atmospheric spectra of nearby exosolar planets and not being able to, then the extra cost is worth it. I'll take getting definite answers to humanity's most pressing questions, over new tools for killing people, any day.
    - Balgair 9y ago
      As would I! Unfortunately, it seems the Realist sect of International Relations seems to be en vouge these last few decades. That said, there is an existential threat to 'science' in general with these large and impossible to replicate engineering experiments. They kinda get subsumed into the 'Big Science' camp where the budgets mean more than anything else and then incentives get muddied. In the physics field, there is still enough animosity and ego between the researchers to keep it all in 'science' and the results don't get massaged like in bio where it's all 'Big Science' now and the results get tweaked. https://en.wikipedia.org/wiki/Realism_(international_relations) https://en.wikipedia.org/wiki/Realism_(international_relatio...
  - saganus 9y ago
    Very nice explanation. Thanks! 15 billion (as per a sibling comment) sounds like a lot, but relative to other, IMO not so important things like said plane, it's not that much. However I wonder if it would be worth it or if that money would be better spent creating a Hubble replacement for example.
    - Balgair 9y ago
      Thanks! I just finished a 14 month class in Optics, so it's fresh for me. The alternative to putting something into space is much more preferable. No matter how big a ground based scope it is, you still have all of that air mucking up the data coming in and you just can't get as good of data. Space is just so much better, as you know, it is mostly empty of the matter we are trying to look at. Granted, for many EM frequencies, ground based is fine. But a lot of atoms we are trying to look at happen to be present in the air too, messing up the data. Space costs a lot more, but I think there is no comparison in the long run. The dark side of the moon would be a good combo of both advantages though. You could build and also maintain and modify a very very large telescope with out any air or other ground based interference. The flip side is that it would be even more remote than current space based telescopes and therefore more expensive to get things to, like people, air, water, food, and fuel. But, hey, it's the flipping Moon! Like, we have a semi-good reason to go back now! For science!
- goatlover 9y ago
  A quick search shows that the largest optical telescope is only 10.4m, and we would probably want to put it in space, free of atmospheric distortion.
afterburner 9y ago
They did plan one (maybe you were thinking of it), but passed in favour of a 39m one: https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope We certainly can't visit these places for quite some time though.
- kuschku 9y ago
  And the 60 or 100m OLT will likely still be built over the next decades. ESO is not going to give up, and they don't have to fight with science-deniers for funding, so there's not much to worry about yet.
WednesdayThrow1 9y ago
Maybe tech giants like Apple and Google should start using some capital to fund awesome ideas like this.
- BigChiefSmokem 9y ago
  Unless they can explain to their shareholders what the benefit of that overwhelmingly long-term investment will be I don't see it happening. Maybe after SpaceX becomes a massively profitable company in the same vein as the tech giants, but not before. Bill Gates also made it painfully clear that he wants his money to go to issues we can resolve right now here on Earth like renewable energy, clean water, fighting disease, etc, which is why philanthropists like him avoid funding anything space-related. They want to witness the fruits of their investments within their lifetimes.
  - WednesdayThrow1 9y ago
    I've yet to see a non emotional explanation for why diversity hiring is good over meritocracy, yet that is thrust upon shareholders.
    - mastazi 9y ago
      I am afraid that you are being downvoted by people who didn't get your point at all. Not everything a company does is always related to medium-short term returns and most shareholders probably get that.
    - andrepd 9y ago
      If nothing else, it's good PR.
    - vidarh 9y ago
      That first of all depends what you mean by "diversity hiring". You assume it is not about meritocracy, but most diversity programs are exactly about trying to cut through biases and ensure a meritocracy. I see setting the two up against each other as largely a strawman - I don't know anyone pushing diversity programs that don't believe it is about evening the playing field rather than providing anyone with an advantage above and beyond their merits (I'm sure they do exist, but I haven't met any). Consider this: Let's assume group A and group B both follows a bell curve in terms of abilities. Let's assume they're not equal. Maybe group B is shifted so that only 3% of group B can compete with the top 10% of group A, for example. Now, if you hire exclusively from group A, and you due to competition for resources end up hiring from the top 20% of group A, you are losing out - there are then substantial numbers of candidates in group B that outperform people you are willing to hire from group A. That is a non-emotional explanation for why diversity is good unless we're in a world where current distribution already accurately reflects merits: Even if you assume that there are substantial differences in abilities between genders or races, unless you can consistently rule out that anyone in these groups are able to compete on abilities, creating an environment that is non-inclusive will leave your competitors with access to better people than you have. The best way of ruling that out, if you believe these groups have different distributions of abilities, is to carefully control for biases and recruit on ability. Now, if you mean quotas where metrics of abilities are ignored in favour of hiring people belonging to specific groups, then that changes the issue, though sometimes such quotas can also be justified if you have reason to believe the metrics used are flawed. E.g. in the UK private schools tend to outperform state schools on A-level grades (equivalent, roughly to SATs / high school diplomas; used for university applications), but the conditions a top student in state school works under also makes it likely that their grades under-represents their learning abilities vs. private school students under equivalent conditions - differences in class sizes and available resources does make a difference in exam performance, and if you can correct for it, it makes sense to do so. If you don't, it may make sense to use quotas to ensure you safeguard your ability to skim the best candidates from these groups. Incidentally, taking more students from state schools would on average be likely to take more black students, for example. My (black, female) ex is on the diversity board of a major investment bank's offices in the UK, and is struggling with exactly this: The bank in question almost exclusively hires from a set of private schools where white men dominates, and sees "diversity" as being about attracting the few black people and women from those schools, rather than hiring by ability without looking at which schools the candidates are from, which would let in far more women and black people. This is before taking into account other factors, such as positive PR with customer groups that hold increasing importance. In other words, there are substantial cold, hard, emotionless reasons to push for less biased hiring, and the proponents of most diversity programs believes that these will provide more diversity through meritocracy, not despite it.
outside1234 9y ago
I thought I read that the state of the art is actually combining many smaller lense telescopes into a virtually larger mirrored one. Or did that fail in practice?
- hueving 9y ago
  You mean this, right? https://en.wikipedia.org/wiki/Astronomical_interferometer https://en.wikipedia.org/wiki/Astronomical_interferometer
2845197541 9y ago
>Why are we here? What do you mean by this?
- ExactoKnight 9y ago
  Finding the existence of life on another planet holds MAJOR implications for many organized and unorganized religions. It would tell us whether abiogenesis and life is common, or something truly unique. So while discovering life on another planet wouldn't answer exactly "why we are here", it would go a hell of a long way in shaping our answers to that question.
  - 2845197541 9y ago
    I apologize for being semantic, but I think that would answer the 'how' rather than the 'why.' I understand what you're saying though. As for the religious, well... I believe they will absolutely find a way for there not to be any major implications. New findings will be absorbed into the obfuscatory practice of apologetics.
    - ExactoKnight 9y ago
      Yeah, I really used the first questions as a way to give importance to how big the "Are we alone?" question is on the scale of humanity. That is to say, that arguably "Why are we here" is the only question of more significance than "Are we alone?" If this telescope can answer the second most important question to humanity, that's pretty good.
    - throwawayjaja1 9y ago
      Already been done, see CS Lewis
  - meric 9y ago
    I can't believe you like the idea of discovering alien life so you can use the discovery to troll religions. Surely there's other reasons why this is exciting?!
deleted 9y ago
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hueving 9y ago
>I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. This is because most of society is still struggling with day-to-day tasks like getting housing, clean water, reliable food, healthcare and dealing with physical conflicts. Even people rich enough to not be stuck in the short term future have to be concerned with near term risks like political destabilization countries and climate change. So it's hard to rush to do something like this as a society when we are already rushing to solve acute issues.
- redthrowaway 9y ago
  >This is because most of society is still struggling with day-to-day tasks like getting housing, clean water, reliable food, healthcare and dealing with physical conflicts. It's been nearly 100 years since anyone struggled with that in the West. Nobody's expecting Eritrea to put a satellite in orbit.
  - meric 9y ago
    Yes even most people in Pakistan/India have access to those, plus broadband internet. Yes I've been there.
    - deleted 9y ago
      [deleted]
    - sumedh 9y ago
      > Yes even most people in Pakistan/India have access to those, plus broadband internet. Yes I've been there. Indian here, lot of people in metro cities dont have clean water. Most middle class and rich people use water filter to clean the water in their house. Forget the villages.
      - meric 9y ago
        Oh well I stayed in Pakistan cities and villages and farms and there's clean water, housing and mobile broadband... Sorry to hear the state in India - I incorrectly assumed they were ahead due to higher GDP per capita.
spenczar5 9y ago
Very large telescopes can achieve great resolving power, but they run up against atmospheric turbulence, particularly in many of the spectral regions we care about for checking out exoplanets. Radio light passes right through the atmosphere for the most part, which is why you see very large radio telescopes, but they're not very practical for infrared or visible light scopes. Space-based telescopes are a better avenue. You can achieve much better resolution in practice with a much smaller telescope. There's no atmosphere to block you, and instruments can capture light of any frequency. Cost is the main disadvantage, but delivery of satellites (and maintenance) to space is getting cheaper and cheaper. All of which is to say that I agree we should be spending more on astronomy. That was your main point, of course. I disagree with the particulars, and think we should be more willing to go to space.
- hnau 9y ago
  adaptive optics on earthbound telescopes have allowed them to easily surpass hubble's resolution nearly a decade ago. it's also a lot easier to service telescopes on the planet than something orbiting at the ideal L2 point, some 1.5 million km from earth.
  - wtvanhest 9y ago
    This is extremely far from my area of expertise so I am probably wrong, but I imagine that at some point we will advance earth based telescopes to the point where we get diminishing returns when considering atmospheric disturbance. At that point, it will make more and more sense to launch space based telescopes. But... if we wait until we reach that point in the diminishing returns curve, than we lost valuable innovation time/expertise in space based technology. My hunch is that if we wanted to get the best telescope tech in any given period of time, we should do both and watch as the two types of technologies converge.
    - aptwebapps 9y ago
      What do you mean by the two types of technology converging?
cetalingua 9y ago
>Why are we here, and are we alone How about we first at least try to understand life on Earth? We are definitely not alone, there are other conscious beings on this planet. After decades of studies we still have no idea what a humpback whale's song means. Bottlenose dolphins have at least 2 if not 3, sound generating mechanisms that could work simultaneously. The amount of information that can be encoded is enormous. Yet, we are still to learn what a single dolphin's call means. We know the function of some meercats' calls or praire dogs' calls, but despite 60 years of research we are yet to decode a function of at least one dolphin call, let alone something more complex like beluga chatter or a humpback song.
- function_seven 9y ago
  I'd rather not have astronomers working on decoding dolphin calls. You imply there's a shortage of biologists, and if we just suspend space exploration and divert those minds to marine biology, things will get better.
  - theonething 9y ago
    Or maybe they are talking about funds and where to invest them.
  - cetalingua 9y ago
    No,not exactly. There is a shortage of funding and also of creative approach. We cannot ask a question "are we alone" unless we know exactly what a whale sings about (if anything) or what crazy complicated dolphin or beluga chatter means. Besides, if we are ever to encounter any sort of alien life, how can we decode any signals or messages if we cannot even decode our own earthlings signals?
    - function_seven 9y ago
      > We cannot ask a question "are we alone" unless we know exactly what a whale sings about (if anything) or what crazy complicated dolphin or beluga chatter means. I don't follow. You could say the same thing about any Earth-bound phenomena. There is an endless supply of interesting things to study on our planet. There's also an endless supply of space exploration waiting for us. To pick one to the exclusion of the other seems very shortsighted, given that we don't know what we'll find in either place. Seems like pursuing all avenues of exploration is the best way to move us forward.
logfromblammo 9y ago
I don't really care what the aliens taste like when I'll be bringing pigs, cows, and chickens on whatever ship I use to go visit them. It is clear to me that the purpose of Earth-life is to spread and assimilate all matter that it may encounter, and the purpose of humanity is to build and launch Earth's reproductive spores. If we are not alone, those other guys had better have some good antibiotics, because we're coming. Right now, it seems like we'll be moving at just a small fraction of c, but slow and steady can still win a race with only one contestant. The important question is therefore "Once we're all dressed up and ready to go, whats our heading?" So with respect to telescopes, would it be better to invest that in the ships, and simply launch toward any random nearby star, to be surveyed by the breeding population en route over the next few centuries, or would it be better to sacrifice a ship or two in order to send the ones we do build toward more promising stars?
menzoic 9y ago
I'm flabbergasted that as a society we aren't towards immortality.
simonebrunozzi 9y ago
What would be the cost for it? Just curious if you or others have a ballpark estimate.
deleted 9y ago
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avip 9y ago
Not sure the gigantic telescope could deliver on its promise to answer "Why we are here".
kiliantics 9y ago
Europe is building one that's 40m: https://en.wikipedia.org/wiki/Extremely_Large_Telescope https://en.wikipedia.org/wiki/Extremely_Large_Telescope
- MrF3ynmann 9y ago
  Telescope names are becoming ridiculous... Very large, extremely large, what's next? Super duper large?
  - DigitalJack 9y ago
    Hexamegagigabyte son.
  - eponeponepon 9y ago
    Overwhelmingly Large. No, seriously: https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope
ugh123 9y ago
I'm all in favor of science funding, especially projects that drive and give back technology capabilities to society. But I would like to see more balance and preference to solve hunger and poverty around the world. To me that question is high on the list as well. And preferably more so.
- aaronblohowiak 9y ago
  What would your target be for government funding of space as a percentage of all government spending?
  - ugh123 9y ago
    Without going too deep into it, some kind of system that allows spending somewhere only if gains/improvements are made elsewhere.
- rb666 9y ago
  What is the point of solving hunger and poverty when we are unable to solve climate change? Having more people and more people who can afford luxuries will only make that problem worse. I know it's a tough argument to swallow, but that doesn't make it less true.
  - paulrouget 9y ago
    What's your argument exactly? Saving more people will worsen the climate situation?
    - rb666 9y ago
      Yes, that's just facts. We thus need to do both, only saving people will be pointless, if there's no livable planet for them.
Retra 9y ago
Do you realize how far away that star is? It would take 40,000 years just to reach the nearest star if we travelled at the speed of the fastest human created object in history. Why do you need to see a habitable planet soon? If you can't survive that trip, it means almost nothing.
- ExactoKnight 9y ago
  Not at all. I don't care about traveling there, I want to know about what other life exists. Once we find a good target, the Breakthrough Starshot program is one example of a promising project that could get us results within our lifetime.
  - Retra 9y ago
    Breakthrough Starshot will get you to a negligible number of stars. Fewer than ten, probably. You think one in ten stars has life?
    - dTal 9y ago
      That wouldn't necessarily be a surprising figure. I might even be tempted to assign a similar probability to finding life elsewhere in the Solar System.
andrepd 9y ago
Putting it bluntly: I'm not flabbergasted because I don't live in a bubble. The great majority of people in this planet have more pressing things to worry about than a 100 metre telescope, things like housing, having food for tomorrow, money, not getting killed, not getting raped, not getting exploited by rich oligarchs/the government, etc etc. Man, I too wish we had more money for large scale scientific endeavours, but I am not flabbergasted that we don't; I can see perfectly why not.
- ExactoKnight 9y ago
  The money is there. U.S. military spending far exceeds spending on science. By another commentators estimate, the 100 Metre Telescope would cost ~$15 billion to build. In comparison the F-35 fighter jet program cost $168 billion, and in 10 years the U.S. will spend roughly $5.5 trillion on its military.
  - andrepd 9y ago
    The point is that if you can convince people to demand a budget cuts for the military, they will almost surely demand to allocate the funds to more pressing needs than space exploration. Most people would sooner want that money spend on things that could improve their lives in a tangible and immediate way than spend it on something that does not benefit them directly in any way.
    - imron 9y ago
      I guess we need to discover life on another planet, to convince the military to start spending its budget on space related technology.
      - jessaustin 9y ago
        Since money is what motivates the military-industrial complex, we only need to decide that all future telescopes will be built by armaments manufacturers, because after all the aliens could be planning a preemptive strike. Then all sorts of senators, lobbyists, etc. will be trying constantly to increase telescope spending.
notreallythough 9y ago
100? why not 1000!?
virtualwhys 9y ago
> Why are we here, and are we alone. An old friend once said, "We're all alone together". I replied, "I can't handle that". "Well, can you handle this?", he said, with arms spread wide to the sky, laughing. Not to be anti-technology, but it may well be that the answers to life's questions depend on nothing.
diogenescynic 9y ago
Meanwhile, some of the smartest and most highly paid people are trying to figure out ways to get people to click more ads. Seems like we are sure squandering our limited time and resources as a species.
daveheq 9y ago
You're hilarious, where's the maximized profit in that?
mturmon 9y ago
The corresponding space telescope for exoplanet detection and spectral characterization is being planned for sooner than you may expect: https://www.jpl.nasa.gov/habex/ https://www.jpl.nasa.gov/habex/. This, or a similar concept, is hoped to be in the upcoming National Research Council decadal survey which recommends astronomical priorities for the 2020s. Current designs require as little as 4 meters. Stability is one advantage of space telescopes. Integration times for spectral characterization can run into days.
- ExactoKnight 9y ago
  Promising developments, but christ, could they move any slower?! We know what technology we need to build. Why must we wait a full two more years for a report to get finished before even beginning funding proposals on which path to pursue, before beginning any construction or engineering?! None of us are getting any younger. I know this is complicated technology to build, but contrast how fast technology moves in the valley compared to this, and you can see the ways in which NASA could really use a bit of startup hustle... (like back in the 60's, when NASA engineered and landed people to the moon within a decade.) There just appears to be no sense of urgency at all.
  - hyeonwho2 9y ago
    When money is tight, those in charge of allocations get more beaurocratic, thus wasting more money. It would be fun to see part of NASA run on design/execution challenges. Have 5000 postdocs on salary, then offer a ($1B-X) bonus for the team which designs and launches a space telescope for X.
  - hyeonwho2 9y ago
    When money is tight, those in charge of allocations get more beaurocratic, thus wasting more money. It would be fun to see part of NASA run on design/execution challenges. Have 5000 postdocs on salary, then offer a ($1B-X) bonus for the team which designs and launches a space telescope for X.
  - mturmon 9y ago
    I don't have time to reply to this with the level of detail required, but I'll just say that you underestimate the level of tech needed to deploy a mirror this good, and you overestimate how much we understand the instrument design issues. That is, we don't know what to build. The trade studies are highly complex (how big the aperture is, how long the mission is, how much propellant is needed to slew the spacecraft, what the yield will be in terms of number of spectral characterizations, whether you need an external star shade). The star shade, if needed, would be a separate spacecraft. General comparisons to "how fast technology moves in the valley" are not specific enough to benchmark what's needed for this rather unique mission.
Zeklandia 9y ago
JWST will do just this!
narrator 9y ago
Anything further than a 100th of a light year past the edge of the solar system we aren't going to be able to send a probe to so why bother except to provide subject matter for sci-fi. Even if we see that there is intelligent life on that planet there's nothing we can really do about it. If they are a few hundred years ahead of us technologically they know about us and don't care. If they are a few hundred years behind they won't be able to receive our transmissions. I know science nerds need a wondergasm, but until we get some decent deep space propulsion technology it doesn't freaking matter. Seriously, except for some cool TV shows what tangible benefit had deep space cosmology brought us in the last 40 years?
tobmlt 9y ago
In principle, I am right with ya. We need ways of beating (or at least coping with), the diffraction limit. It's fun to think of, say, stuff like this: https://arxiv.org/abs/1604.06351 https://arxiv.org/abs/1604.06351 (as far as big lenses go) Using the sun as a gravitational lens would be pretty sweet. I have a feeling we will have some more tricks to play with E&M locally before we can go to space on that scale though. edit: My own semi-blind musing has made me curious: metamaterials for super-lensing: https://arxiv.org/pdf/0905.0263.pdf https://arxiv.org/pdf/0905.0263.pdf entanglment enhanced microscopes?!: https://arxiv.org/abs/1401.8075 https://arxiv.org/abs/1401.8075 (@shpx linked to this quantum stuff before me, by the way)

saganus 9y ago

Isn't building a 100m telescope incredibly hard? does that kind of technology exist already? (I genuinely don't know). Also, what would the effect of the atmosphere be in such a large telescope? would a bigger mirror increase or decrease the effects of Earth's atmosphere for these kind of observations?

Balgair 9y ago
Noise is noise. If you put gain on the signal in general, you'll put gain on the noise too. That's why James Webb is in space and the 30 Meter Telescope (TMT) is in Hawaii, less atmosphere and clear air means less noise inputted. Still, the TMT is pretty darn good. So yes, you are correct, bigger telescope means more noise (in gestalt) while in atmosphere. THe reason bigger is better is because you can resolve smaller angles. The Fourier treatment of optics is useful here. The radius of your lenses/reflectors sets the limit of the higher spatial frequency. Low spatial frequencies pass through small lenses/refectors and high spatial frequencies pass through larger ones. Therefore the bigger the telescope, the more higher order spatial frequencies you can collect. https://en.wikipedia.org/wiki/Fourier_optics https://en.wikipedia.org/wiki/Fourier_optics Why not a 100 Meter Telescope? Cost and engineering. With these retro reflectors getting so big, you have to worry a lot about thermal expansion and differential levels of it across the whole surface. Also, the structure to hold it has to be monitored really closely in real time to make sure the calculations are accurate. It's not easy. Also, with modern adaptive optics, you'll have apply all the little piezo-motors across the entire surface which goes as the square of the radius, so costs go up geometrically (plus about 15% more for each doubling in surface area due to cabling, power issues, larger facilities with thicker steel beams, more janitors, etc.). If the TMT costs X, then the 100-MT should cost about 11X, and with the 15% doubling factor, its ~15X for only a 3X increase in radius.
- ExactoKnight 9y ago
  > If the TMT costs X, then the 100-MT should cost about 11X, and with the 15% doubling factor, its ~15X for only a 3X increase in radius. The Thirty Meter Telescope cost $1 billion. So the 100 Metre Overwhelmingly Large Telescope would cost ~$15 billion using your ~15x multiplier. That's large, but for perspective: The F-35 fighter jet program cost $168 billion. Like with the Large Hadron Collider, if the extra cost means the difference between being able to crucially measure the atmospheric spectra of nearby exosolar planets and not being able to, then the extra cost is worth it. I'll take getting definite answers to humanity's most pressing questions, over new tools for killing people, any day.
  - Balgair 9y ago
    As would I! Unfortunately, it seems the Realist sect of International Relations seems to be en vouge these last few decades. That said, there is an existential threat to 'science' in general with these large and impossible to replicate engineering experiments. They kinda get subsumed into the 'Big Science' camp where the budgets mean more than anything else and then incentives get muddied. In the physics field, there is still enough animosity and ego between the researchers to keep it all in 'science' and the results don't get massaged like in bio where it's all 'Big Science' now and the results get tweaked. https://en.wikipedia.org/wiki/Realism_(international_relations) https://en.wikipedia.org/wiki/Realism_(international_relatio...
- saganus 9y ago
  Very nice explanation. Thanks! 15 billion (as per a sibling comment) sounds like a lot, but relative to other, IMO not so important things like said plane, it's not that much. However I wonder if it would be worth it or if that money would be better spent creating a Hubble replacement for example.
  - Balgair 9y ago
    Thanks! I just finished a 14 month class in Optics, so it's fresh for me. The alternative to putting something into space is much more preferable. No matter how big a ground based scope it is, you still have all of that air mucking up the data coming in and you just can't get as good of data. Space is just so much better, as you know, it is mostly empty of the matter we are trying to look at. Granted, for many EM frequencies, ground based is fine. But a lot of atoms we are trying to look at happen to be present in the air too, messing up the data. Space costs a lot more, but I think there is no comparison in the long run. The dark side of the moon would be a good combo of both advantages though. You could build and also maintain and modify a very very large telescope with out any air or other ground based interference. The flip side is that it would be even more remote than current space based telescopes and therefore more expensive to get things to, like people, air, water, food, and fuel. But, hey, it's the flipping Moon! Like, we have a semi-good reason to go back now! For science!
goatlover 9y ago
A quick search shows that the largest optical telescope is only 10.4m, and we would probably want to put it in space, free of atmospheric distortion.

afterburner 9y ago

They did plan one (maybe you were thinking of it), but passed in favour of a 39m one: https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope We certainly can't visit these places for quite some time though.

kuschku 9y ago
And the 60 or 100m OLT will likely still be built over the next decades. ESO is not going to give up, and they don't have to fight with science-deniers for funding, so there's not much to worry about yet.

WednesdayThrow1 9y ago

Maybe tech giants like Apple and Google should start using some capital to fund awesome ideas like this.

BigChiefSmokem 9y ago
Unless they can explain to their shareholders what the benefit of that overwhelmingly long-term investment will be I don't see it happening. Maybe after SpaceX becomes a massively profitable company in the same vein as the tech giants, but not before. Bill Gates also made it painfully clear that he wants his money to go to issues we can resolve right now here on Earth like renewable energy, clean water, fighting disease, etc, which is why philanthropists like him avoid funding anything space-related. They want to witness the fruits of their investments within their lifetimes.
- WednesdayThrow1 9y ago
  I've yet to see a non emotional explanation for why diversity hiring is good over meritocracy, yet that is thrust upon shareholders.
  - mastazi 9y ago
    I am afraid that you are being downvoted by people who didn't get your point at all. Not everything a company does is always related to medium-short term returns and most shareholders probably get that.
  - andrepd 9y ago
    If nothing else, it's good PR.
  - vidarh 9y ago
    That first of all depends what you mean by "diversity hiring". You assume it is not about meritocracy, but most diversity programs are exactly about trying to cut through biases and ensure a meritocracy. I see setting the two up against each other as largely a strawman - I don't know anyone pushing diversity programs that don't believe it is about evening the playing field rather than providing anyone with an advantage above and beyond their merits (I'm sure they do exist, but I haven't met any). Consider this: Let's assume group A and group B both follows a bell curve in terms of abilities. Let's assume they're not equal. Maybe group B is shifted so that only 3% of group B can compete with the top 10% of group A, for example. Now, if you hire exclusively from group A, and you due to competition for resources end up hiring from the top 20% of group A, you are losing out - there are then substantial numbers of candidates in group B that outperform people you are willing to hire from group A. That is a non-emotional explanation for why diversity is good unless we're in a world where current distribution already accurately reflects merits: Even if you assume that there are substantial differences in abilities between genders or races, unless you can consistently rule out that anyone in these groups are able to compete on abilities, creating an environment that is non-inclusive will leave your competitors with access to better people than you have. The best way of ruling that out, if you believe these groups have different distributions of abilities, is to carefully control for biases and recruit on ability. Now, if you mean quotas where metrics of abilities are ignored in favour of hiring people belonging to specific groups, then that changes the issue, though sometimes such quotas can also be justified if you have reason to believe the metrics used are flawed. E.g. in the UK private schools tend to outperform state schools on A-level grades (equivalent, roughly to SATs / high school diplomas; used for university applications), but the conditions a top student in state school works under also makes it likely that their grades under-represents their learning abilities vs. private school students under equivalent conditions - differences in class sizes and available resources does make a difference in exam performance, and if you can correct for it, it makes sense to do so. If you don't, it may make sense to use quotas to ensure you safeguard your ability to skim the best candidates from these groups. Incidentally, taking more students from state schools would on average be likely to take more black students, for example. My (black, female) ex is on the diversity board of a major investment bank's offices in the UK, and is struggling with exactly this: The bank in question almost exclusively hires from a set of private schools where white men dominates, and sees "diversity" as being about attracting the few black people and women from those schools, rather than hiring by ability without looking at which schools the candidates are from, which would let in far more women and black people. This is before taking into account other factors, such as positive PR with customer groups that hold increasing importance. In other words, there are substantial cold, hard, emotionless reasons to push for less biased hiring, and the proponents of most diversity programs believes that these will provide more diversity through meritocracy, not despite it.

outside1234 9y ago

I thought I read that the state of the art is actually combining many smaller lense telescopes into a virtually larger mirrored one. Or did that fail in practice?

hueving 9y ago
You mean this, right? https://en.wikipedia.org/wiki/Astronomical_interferometer https://en.wikipedia.org/wiki/Astronomical_interferometer

2845197541 9y ago

>Why are we here? What do you mean by this?

ExactoKnight 9y ago
Finding the existence of life on another planet holds MAJOR implications for many organized and unorganized religions. It would tell us whether abiogenesis and life is common, or something truly unique. So while discovering life on another planet wouldn't answer exactly "why we are here", it would go a hell of a long way in shaping our answers to that question.
- 2845197541 9y ago
  I apologize for being semantic, but I think that would answer the 'how' rather than the 'why.' I understand what you're saying though. As for the religious, well... I believe they will absolutely find a way for there not to be any major implications. New findings will be absorbed into the obfuscatory practice of apologetics.
  - ExactoKnight 9y ago
    Yeah, I really used the first questions as a way to give importance to how big the "Are we alone?" question is on the scale of humanity. That is to say, that arguably "Why are we here" is the only question of more significance than "Are we alone?" If this telescope can answer the second most important question to humanity, that's pretty good.
  - throwawayjaja1 9y ago
    Already been done, see CS Lewis
- meric 9y ago
  I can't believe you like the idea of discovering alien life so you can use the discovery to troll religions. Surely there's other reasons why this is exciting?!

deleted 9y ago

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hueving 9y ago

>I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. This is because most of society is still struggling with day-to-day tasks like getting housing, clean water, reliable food, healthcare and dealing with physical conflicts. Even people rich enough to not be stuck in the short term future have to be concerned with near term risks like political destabilization countries and climate change. So it's hard to rush to do something like this as a society when we are already rushing to solve acute issues.

redthrowaway 9y ago
>This is because most of society is still struggling with day-to-day tasks like getting housing, clean water, reliable food, healthcare and dealing with physical conflicts. It's been nearly 100 years since anyone struggled with that in the West. Nobody's expecting Eritrea to put a satellite in orbit.
- meric 9y ago
  Yes even most people in Pakistan/India have access to those, plus broadband internet. Yes I've been there.
  - deleted 9y ago
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  - sumedh 9y ago
    > Yes even most people in Pakistan/India have access to those, plus broadband internet. Yes I've been there. Indian here, lot of people in metro cities dont have clean water. Most middle class and rich people use water filter to clean the water in their house. Forget the villages.
    - meric 9y ago
      Oh well I stayed in Pakistan cities and villages and farms and there's clean water, housing and mobile broadband... Sorry to hear the state in India - I incorrectly assumed they were ahead due to higher GDP per capita.

spenczar5 9y ago

Very large telescopes can achieve great resolving power, but they run up against atmospheric turbulence, particularly in many of the spectral regions we care about for checking out exoplanets. Radio light passes right through the atmosphere for the most part, which is why you see very large radio telescopes, but they're not very practical for infrared or visible light scopes. Space-based telescopes are a better avenue. You can achieve much better resolution in practice with a much smaller telescope. There's no atmosphere to block you, and instruments can capture light of any frequency. Cost is the main disadvantage, but delivery of satellites (and maintenance) to space is getting cheaper and cheaper. All of which is to say that I agree we should be spending more on astronomy. That was your main point, of course. I disagree with the particulars, and think we should be more willing to go to space.

hnau 9y ago
adaptive optics on earthbound telescopes have allowed them to easily surpass hubble's resolution nearly a decade ago. it's also a lot easier to service telescopes on the planet than something orbiting at the ideal L2 point, some 1.5 million km from earth.
- wtvanhest 9y ago
  This is extremely far from my area of expertise so I am probably wrong, but I imagine that at some point we will advance earth based telescopes to the point where we get diminishing returns when considering atmospheric disturbance. At that point, it will make more and more sense to launch space based telescopes. But... if we wait until we reach that point in the diminishing returns curve, than we lost valuable innovation time/expertise in space based technology. My hunch is that if we wanted to get the best telescope tech in any given period of time, we should do both and watch as the two types of technologies converge.
  - aptwebapps 9y ago
    What do you mean by the two types of technology converging?

cetalingua 9y ago

>Why are we here, and are we alone How about we first at least try to understand life on Earth? We are definitely not alone, there are other conscious beings on this planet. After decades of studies we still have no idea what a humpback whale's song means. Bottlenose dolphins have at least 2 if not 3, sound generating mechanisms that could work simultaneously. The amount of information that can be encoded is enormous. Yet, we are still to learn what a single dolphin's call means. We know the function of some meercats' calls or praire dogs' calls, but despite 60 years of research we are yet to decode a function of at least one dolphin call, let alone something more complex like beluga chatter or a humpback song.

function_seven 9y ago
I'd rather not have astronomers working on decoding dolphin calls. You imply there's a shortage of biologists, and if we just suspend space exploration and divert those minds to marine biology, things will get better.
- theonething 9y ago
  Or maybe they are talking about funds and where to invest them.
- cetalingua 9y ago
  No,not exactly. There is a shortage of funding and also of creative approach. We cannot ask a question "are we alone" unless we know exactly what a whale sings about (if anything) or what crazy complicated dolphin or beluga chatter means. Besides, if we are ever to encounter any sort of alien life, how can we decode any signals or messages if we cannot even decode our own earthlings signals?
  - function_seven 9y ago
    > We cannot ask a question "are we alone" unless we know exactly what a whale sings about (if anything) or what crazy complicated dolphin or beluga chatter means. I don't follow. You could say the same thing about any Earth-bound phenomena. There is an endless supply of interesting things to study on our planet. There's also an endless supply of space exploration waiting for us. To pick one to the exclusion of the other seems very shortsighted, given that we don't know what we'll find in either place. Seems like pursuing all avenues of exploration is the best way to move us forward.

logfromblammo 9y ago

I don't really care what the aliens taste like when I'll be bringing pigs, cows, and chickens on whatever ship I use to go visit them. It is clear to me that the purpose of Earth-life is to spread and assimilate all matter that it may encounter, and the purpose of humanity is to build and launch Earth's reproductive spores. If we are not alone, those other guys had better have some good antibiotics, because we're coming. Right now, it seems like we'll be moving at just a small fraction of c, but slow and steady can still win a race with only one contestant. The important question is therefore "Once we're all dressed up and ready to go, whats our heading?" So with respect to telescopes, would it be better to invest that in the ships, and simply launch toward any random nearby star, to be surveyed by the breeding population en route over the next few centuries, or would it be better to sacrifice a ship or two in order to send the ones we do build toward more promising stars?

menzoic 9y ago

I'm flabbergasted that as a society we aren't towards immortality.

simonebrunozzi 9y ago

What would be the cost for it? Just curious if you or others have a ballpark estimate.

deleted 9y ago

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avip 9y ago

Not sure the gigantic telescope could deliver on its promise to answer "Why we are here".

kiliantics 9y ago

Europe is building one that's 40m: https://en.wikipedia.org/wiki/Extremely_Large_Telescope https://en.wikipedia.org/wiki/Extremely_Large_Telescope

MrF3ynmann 9y ago
Telescope names are becoming ridiculous... Very large, extremely large, what's next? Super duper large?
- DigitalJack 9y ago
  Hexamegagigabyte son.
- eponeponepon 9y ago
  Overwhelmingly Large. No, seriously: https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope https://en.wikipedia.org/wiki/Overwhelmingly_Large_Telescope

ugh123 9y ago

I'm all in favor of science funding, especially projects that drive and give back technology capabilities to society. But I would like to see more balance and preference to solve hunger and poverty around the world. To me that question is high on the list as well. And preferably more so.

aaronblohowiak 9y ago
What would your target be for government funding of space as a percentage of all government spending?
- ugh123 9y ago
  Without going too deep into it, some kind of system that allows spending somewhere only if gains/improvements are made elsewhere.
rb666 9y ago
What is the point of solving hunger and poverty when we are unable to solve climate change? Having more people and more people who can afford luxuries will only make that problem worse. I know it's a tough argument to swallow, but that doesn't make it less true.
- paulrouget 9y ago
  What's your argument exactly? Saving more people will worsen the climate situation?
  - rb666 9y ago
    Yes, that's just facts. We thus need to do both, only saving people will be pointless, if there's no livable planet for them.

Retra 9y ago

Do you realize how far away that star is? It would take 40,000 years just to reach the nearest star if we travelled at the speed of the fastest human created object in history. Why do you need to see a habitable planet soon? If you can't survive that trip, it means almost nothing.

ExactoKnight 9y ago
Not at all. I don't care about traveling there, I want to know about what other life exists. Once we find a good target, the Breakthrough Starshot program is one example of a promising project that could get us results within our lifetime.
- Retra 9y ago
  Breakthrough Starshot will get you to a negligible number of stars. Fewer than ten, probably. You think one in ten stars has life?
  - dTal 9y ago
    That wouldn't necessarily be a surprising figure. I might even be tempted to assign a similar probability to finding life elsewhere in the Solar System.

andrepd 9y ago

Putting it bluntly: I'm not flabbergasted because I don't live in a bubble. The great majority of people in this planet have more pressing things to worry about than a 100 metre telescope, things like housing, having food for tomorrow, money, not getting killed, not getting raped, not getting exploited by rich oligarchs/the government, etc etc. Man, I too wish we had more money for large scale scientific endeavours, but I am not flabbergasted that we don't; I can see perfectly why not.

ExactoKnight 9y ago
The money is there. U.S. military spending far exceeds spending on science. By another commentators estimate, the 100 Metre Telescope would cost ~$15 billion to build. In comparison the F-35 fighter jet program cost $168 billion, and in 10 years the U.S. will spend roughly $5.5 trillion on its military.
- andrepd 9y ago
  The point is that if you can convince people to demand a budget cuts for the military, they will almost surely demand to allocate the funds to more pressing needs than space exploration. Most people would sooner want that money spend on things that could improve their lives in a tangible and immediate way than spend it on something that does not benefit them directly in any way.
  - imron 9y ago
    I guess we need to discover life on another planet, to convince the military to start spending its budget on space related technology.
    - jessaustin 9y ago
      Since money is what motivates the military-industrial complex, we only need to decide that all future telescopes will be built by armaments manufacturers, because after all the aliens could be planning a preemptive strike. Then all sorts of senators, lobbyists, etc. will be trying constantly to increase telescope spending.

notreallythough 9y ago

100? why not 1000!?

virtualwhys 9y ago

> Why are we here, and are we alone. An old friend once said, "We're all alone together". I replied, "I can't handle that". "Well, can you handle this?", he said, with arms spread wide to the sky, laughing. Not to be anti-technology, but it may well be that the answers to life's questions depend on nothing.

diogenescynic 9y ago

Meanwhile, some of the smartest and most highly paid people are trying to figure out ways to get people to click more ads. Seems like we are sure squandering our limited time and resources as a species.

daveheq 9y ago

You're hilarious, where's the maximized profit in that?

mturmon 9y ago

The corresponding space telescope for exoplanet detection and spectral characterization is being planned for sooner than you may expect: https://www.jpl.nasa.gov/habex/ https://www.jpl.nasa.gov/habex/. This, or a similar concept, is hoped to be in the upcoming National Research Council decadal survey which recommends astronomical priorities for the 2020s. Current designs require as little as 4 meters. Stability is one advantage of space telescopes. Integration times for spectral characterization can run into days.

ExactoKnight 9y ago
Promising developments, but christ, could they move any slower?! We know what technology we need to build. Why must we wait a full two more years for a report to get finished before even beginning funding proposals on which path to pursue, before beginning any construction or engineering?! None of us are getting any younger. I know this is complicated technology to build, but contrast how fast technology moves in the valley compared to this, and you can see the ways in which NASA could really use a bit of startup hustle... (like back in the 60's, when NASA engineered and landed people to the moon within a decade.) There just appears to be no sense of urgency at all.
- hyeonwho2 9y ago
  When money is tight, those in charge of allocations get more beaurocratic, thus wasting more money. It would be fun to see part of NASA run on design/execution challenges. Have 5000 postdocs on salary, then offer a ($1B-X) bonus for the team which designs and launches a space telescope for X.
- hyeonwho2 9y ago
  When money is tight, those in charge of allocations get more beaurocratic, thus wasting more money. It would be fun to see part of NASA run on design/execution challenges. Have 5000 postdocs on salary, then offer a ($1B-X) bonus for the team which designs and launches a space telescope for X.
- mturmon 9y ago
  I don't have time to reply to this with the level of detail required, but I'll just say that you underestimate the level of tech needed to deploy a mirror this good, and you overestimate how much we understand the instrument design issues. That is, we don't know what to build. The trade studies are highly complex (how big the aperture is, how long the mission is, how much propellant is needed to slew the spacecraft, what the yield will be in terms of number of spectral characterizations, whether you need an external star shade). The star shade, if needed, would be a separate spacecraft. General comparisons to "how fast technology moves in the valley" are not specific enough to benchmark what's needed for this rather unique mission.

Zeklandia 9y ago

JWST will do just this!

narrator 9y ago

Anything further than a 100th of a light year past the edge of the solar system we aren't going to be able to send a probe to so why bother except to provide subject matter for sci-fi. Even if we see that there is intelligent life on that planet there's nothing we can really do about it. If they are a few hundred years ahead of us technologically they know about us and don't care. If they are a few hundred years behind they won't be able to receive our transmissions. I know science nerds need a wondergasm, but until we get some decent deep space propulsion technology it doesn't freaking matter. Seriously, except for some cool TV shows what tangible benefit had deep space cosmology brought us in the last 40 years?

tobmlt 9y ago

In principle, I am right with ya. We need ways of beating (or at least coping with), the diffraction limit. It's fun to think of, say, stuff like this: https://arxiv.org/abs/1604.06351 https://arxiv.org/abs/1604.06351 (as far as big lenses go) Using the sun as a gravitational lens would be pretty sweet. I have a feeling we will have some more tricks to play with E&M locally before we can go to space on that scale though. edit: My own semi-blind musing has made me curious: metamaterials for super-lensing: https://arxiv.org/pdf/0905.0263.pdf https://arxiv.org/pdf/0905.0263.pdf entanglment enhanced microscopes?!: https://arxiv.org/abs/1401.8075 https://arxiv.org/abs/1401.8075 (@shpx linked to this quantum stuff before me, by the way)