I was thinking the same thing... right away my brain went "what about a NASA-ESA collaboration?" because this is a gap in our understanding that really needs investigation.
Don't worry, USA will waste hundreds of billions sending arms to nazis and terrorists before spending a single cent on this. Science? Pfft, arms companies pay a lot to get their puppets elected, maybe if these dumb nerds cough up a few billions in bribes-- I mean PAC funds the congress will think about funding progress, too...
And then all that needs to happen is a single hook not catching anything for the proposers of this plan to look very silly and dumb, and you can't even send humans to fix it because no one will scale 200 meter tall cliff in space suit...
Build a lunar telescope as far from noisy primates as possible.... Kickstart lunar development by invading noisy primates. The classic victim of its own success.
Yes. For this project, NASA/ESA would need a relay satellite in lunar orbit (or L2 as mentioned), but due to the telescope not being able to work when the sun shines on it, that relay satellite might face 50% of its time without work. NASA/ESA might therefore consider a something else to make use of that relay satellite.
Firing all those harpoons in just the right way sounds like it has no chance of not going wrong. But then I said the same thing about that sky crane thing, so shows what I know.
Language time! The “e” in “Chang’e” is a schwa in the International Phonetic Alphabet; that is, the same vowel as in “uh” or “um” in most English accents. “Chang-uh”. Bonus round! The “ch” in many Chinese words, including the name of the moon goddess, Chang’e, represents a very interesting consonant cluster. In the IPA, English “ch” is usually represented as two consonants articulated in succession, “t” and “ʃ”, typically represented as “sh” in English. In Chinese, there is an additional variant of “tʃ” which includes a retroflex fricative consonant, rendered as “ʂ” in IPA; in practice, this is a little like curling your tongue into the English “r” shape while pronouncing “tʃ”. This one probably requires a bit more practice for speakers of the various English dialects, and easier to sort of swallow outside of a Mandarin Chinese speaking environment compared to the “uh” vowel, which is both used in English and quite prominent in the word-final position. (This is all for pronunciations in Mandarin Chinese, by the by, no idea how things shake out in Cantonese or any other of the various languages/dialects under the “Chinese” umbrella.)
When I was an undergrad I enjoyed this channel as entertainment, and now as a PhD candidate I think hmm should I devote the next five years of my life studying this
This feels like the digital equivalent of PBS slipping NASA a $20 bill with a sticky note that reads "please build that super cool radioscope on the moon :)"
11:00 it's the other way round: it has to be heavier at the center. And to support the mesh better it is a good idea to have additional ropes between the main support strings (spider-web like) - this can also do the job to create the parabolic shape, because they would lessen the tension of the main ropes in the center.
The telescope will be very thin but strong thread, dust will mostly go through the holes. Larger pieces might punch through but won't make enough difference to degrade performance. A radio telescope does not have the same issues that an optical one does where impacts will damage the lens and diffract light.
Roughly 1 in 12 billion chance per day. Assuming the timescale for this project is 25 years, it has a 1 in 1.3 million chance of getting hit by anything large enough to do meaningful damage. EDIT: Sorry, you asked how often. About once every 25 million years.
@@Mp57navy I don't want to say whether or not it's safer. I was just giving the chance of meaningful impact (which is lower for anything on Earth due to the atmosphere). But there are no other telescopes driving around to run into it, and the telescope won't take codeine before using the restroom. But it has a lot more risks in getting there. And once it gets there, the intense solar radiation isn't doing it any favors for longevity. I also didn't answer the dust portion of the question because I don't actually know the answer on that. We have technology to deal with the electrostatically charged dust by using it to generate power and using that power to negate the charge. But I don't know if that technology is beyond the prototype phase yet. That said, they won't launch it if they don't have some dust management technology in place.
… I’ve always been impressed with the care you’ve taken in pronouncing foreign names, names of scientists, etc., and now the Latin feminine plural suffix, -ae, pronounced, just as my Latin teacher said! You’re doing much better than almost any biologist :-)
Started off studying electronics in '73 and fell in love with physics. I had no idea we were so ignorant in astronomy at those frequencies, as soon as you set up the problem, it is like well duh, the ionosphere. wow and a whole new data set for sky guys ...
This is so cool-I've been a fan of this idea since reading an Arthur C. Clarke story where it was done with a spinning pool of mercury, but I never thought they'd figure out a way to do it with just a single incredibly clever deployable probe. The most obvious objection is whether all the harpoons will find purchase and not glance off a boulder or pomf into a big mound of dust, but maybe robotic piledriving is more advanced than I realize or it can be designed in a way where it doesn't need every single wire to maintain its shape-Or if it's a self-contained probe maybe we can Voyager it and build a few of them so at least one is likely to get them all in. Either way it seems like a fantastic idea for a first look, and if it uncovers the iceberg tips of some exciting cosmic mysteries it can be followed up one day with an actual facility.
Always love watching your videos - and this is probably the only one I’ve understood 100%!! Would love to see (actually won’t see it!) a telescope like this up and running - we can only imagine what we find…
Varying the thickness to change the caternary into a parabola shape is so genius and yet so simple I'm amazed previous proposals hadn't thought of it before
That is such a cool idea! I love the fact we are considering lots of ways to gather data of any/all kinds. It's easy to understand the budget restrictions and whatnot, such as extremely great ideas just too expensive and although likely to be incredible, it's just too risky or costly.... I wonder if it's been considered to put a relatively large number of small antenna type dishes over the surface and use the quantity over large areas that are linked in something like an ad-hoc network maybe in separate clusters of antenna that link up then that information is relayed over larger repeater dishes or network to the side of the moon we can receive proper communication from so that data speeds should be able to keep up with the incoming information much more effectively and less delay I would think. Can't wait to see what's next! Great video! 🍻🌎❤️🎶🕺🚀
@@nadsenoj8719 I gotcha... I figured it was close to something already considered and all... but hey, it's fun trying to figure all this stuff out! Have a great day/evening! 🍻
Small dishes will be unusable at the long wavelengths expected from that far away. Instead, an array of wire antennas such as used at the Long Wavelength Array, New Mexico (256 antennas) or LOFAR across Europe (12000 antennas) would achieve astounding sensitivity on the Moon.
@@witwisniewski2280 that's more of what I was thinking but maybe start with smaller clusters and scale upwards when viable... I'm sure someone will come up with something awesome and crazy and probably 10x better anyways lol just fun to think about 😁 Enjoy your evening!
0:00: 🌑 A giant radio telescope on the far side of the moon could allow astronomers to see further back in time than ever before. 3:40: 🌌 The lunar crater radio telescope could provide a glimpse into the cosmic dark ages and help understand the early universe. 6:51: 📡 The video discusses the importance of a giant space radio telescope on the moon for detecting and studying radio waves. 9:48: 🌕 The Lunar Crater Radio Telescope (LCRT) is a proposed fixed-dish radio telescope on the moon that uses a unique hanging design. 12:49: 🌌 NASA is considering turning the far side of the moon into a giant radio telescope to peer into the time before stars at the beginning of space time. 16:07: 🌌 Dark matter can potentially diminish over a long timescale, causing galaxies to fall apart. 18:34: 📺 The video discusses the random nature of particles and how they can affect spacetime. Recap by Tammy AI
thanks for the information one thing i should point out both the moon and mars are going to need a dedicated communications net. having long communication blackouts will really not be acceptable in the long run
Some combination of communication relay sats at Lagrange points and synchronous orbits may be a useful investment. We should be able to get the internet on the Moon and Mars using existing tech. JWST needs a better radio link too!
10:53 catenary! i used to work with those all the time when doing EM field studies on high power transmission lines. line tension and weight are your two variables iirc, plus temperature sag. (whoa, changing the thickness of the line to change the shape of the curve, that's rad)
If Artemis actually goes as planned and SpaceX SuperHeavy development goes as planned, such a project may very soon become not only possible, but also not astronomically expensive to actually happen.
I've always had the picture in my head that we should have a telescope orbiting Neptune and Jupiter. Relays at Saturn, Mars and the Moon. That would give us the most optimal view distances and would be a testament to our engineering feats. Yes, it would be way more challenging to upgrade them in the future, but at the same time, it would give us invaluable insights.
earth and the sun are still the brightest radio objects around - and the only place where you are guaranteed to avoid the earth is the far side of the moon. You don't get too much extra by going further out. And Jupiter (with its massive magnetic + radiation field) isn't an amazing place for telescopes :) Further out just merges the radio noise from sun and earth into similar parts of the sky.
@@andytroo That is a VERY fair reason for why we haven't done it with our more advanced tech. I would still love to see what type of visuals we would get with a lens telescope that sent images back to us from that distance though. I'd imagine the view of the inner planets would be quite spectacular.
It's funny. When you consider the entirety of _all_ UA-cam viewers watching _all_ the different videos available on UA-cam, the majority of viewers probably want to meet movie stars and "influencers"... In contrast, I'm jazzed that I was able to attend in person (on two different occasions) lectures by Roger Penrose. And I would love to meet Matt O'Dowd and other physicists. These kinds of people are *my* heroes! 😎👍
I think rather than not knowing about the ionosphere, they're just patiently waiting for the possibility we prove ourselves "worthy" enough to hear the message by leaving the cradle.
@@JesusFriedChrist What if they know about it and send it in a way that only sufficiently competent and developed civilizations can receive? IE ones spending on pure research/scientific projects, not just arms race in space?
@@JesusFriedChrist you're assuming that extraterrestrial life will be earthlike, from an earthlike planet. one thing we know life can do is "eat" radiation to live. it's a rare thing here on earth, but it does happen. imagine, if you will, a planet with no ionosphere where radiotrophic life evolves to be the dominant form. intelligent life from this stock would probably make the same mistake you just did, and assume any life they find will be radiotrophic, from a world with no ionosphere. therefore, they'd send signals that would bounce off of our ionosphere.
We should never be putting things on the moon "just because". Space should be treated as or better than we treat national parks and rainforests. Carefully. Very carefully.
@@SolidSiren To be blunt. The only things alive on the moon are when humans do things. Industries and science programs can be put there with no ill effects on Earth. Unless you don't know the difference?
No, there's generally not been many that orbit the moon and they've had poor resolution since none were especially designed to pick up generic radio signals. They were all built for other things.
I've always been confused about the red shifting of light. I understand (mostly) the concept, but my question is, does light get red shifted all the way down to nonexistence or is there a remnant of some sort? energy and/or mass just doesn't stop existing, right? Can light that has lost nearly all of its energy change from its wave/particle duality into something below the known spectrum?
As far as I understand (not a professional), it can only asymptotically approach zero frequency or exponentially approach infinite wavelength. It never truly disappears. Only in the case of a black hole would it even be a question, because even the farthest reaching photons from across the cosmos are "only" stretched by a factor of a million or so. But in black holes, it's not red shift that swallows the photons, it's just the fact that all geodesic paths inside the event horizon lead to the singularity. There's no escape route, red shifted or otherwise. Although during the process of falling in, you can have photons that are emitted from near the horizon that are extremely red shifted due to the time dilation. So there's a limit as you approach the horizon where photons from a source there would approach infinite wavelength. Of course that would make their exact position highly indeterminate. And it would blend in to the Hawking radiation from the black hole as the wavelength reached the size of the BH itself, in practice becoming undetectable via any instruments available. Also bear in mind, the law of conservation of energy does not apply to cosmic inflation, as the underlying symmetry is broken on that kind of scale. There was an episode of Science Asylum about that. I'm not sure how to explain the red shift due to gravity of General Relativity in those terms though.
In th4e case of gravitational redshift, mass\energy is conserved. A photon escaping a gravity well is equivalent to a tiny rocket, pushing itself up by ejecting something behind it. The energy lost by the photon is kept by the massive object. Any observable photon will never be redshifted to nothing, that's not physically possible. The ones we think of at doing so will either be trapped on the event horizon of a black hole or fall into it. On a cosmic scale it's a bit more tricky. Traditional energy is not conserved, but something more broad, involving the 'energy-momentum four vector' IS. There too a photon cannot be redshifted into nothing, there must always be something remaining since a real particle cannot just cease existence.
Great video as always Matt, have you done a video on/are there any proposals for, the building of a rotating ring orbital station to allow longer term stays in orbit?
I’m beginning to think that Isaac Arthur was onto something when he said, and I’m paraphrasing: ”Give NASA the budget to build a lunar colony, and you’ll end up with a lunar telescope instead.” This is why we need a space development agency, lol.
Antenna array telescopes are vastly more flexible than dishes. The modern array digitizes the actual wavefront over some large area, essentially receiving all incident radio waves at once. Numerical processing then selects a direction or beam to look with, numerically focusing on an object. Multiple beams in diverse directions can be observed at the same time and each beam is instantly steerable. The limitation is data bandwidth for conveying the wavefront to the computers, and the processing bandwidth of the computers themselves.
Matt, don’t forget the 20Mz noise from Jupiter - an HF radio wave can penetrate the ionosphere if the angle is correct, it doesn’t always bounce off into space.
Yeah, HF radio waves interact with the ionosphere in deeply strange and unpredictable ways, depending largely on space weather. Sometimes that 20MHz can come right in, sometimes it bounces off, on rare occasions it comes in and then bounces around inside the ionosphere and makes a real hash of the 15M band.
I prefer wide array of dipole antenna to parabolic mesh dish. Dipole antenna can be steerable like AESA radar to observe whole sky. And it can be deployed gradually over long time. First with few antenna, next 10's of antenna and finally 100's of antenna on moon's surface. The antenna can be scattered over very wide area like few km-10 km per antenna and used as long base line interferometry telescope array, which will improve spatial resolution greatly.
If they do this, I think the crater it ends up in should be called Arecibo Crater in memory of the late giant. Then we get an Arecibo telescope back again :)
I am cool with using my tax dollars for a moon telescope, but the middle-class homeowners are just going to say we need that money for more bombs and weapon's.
Hey there. I'm a middle class homeowner and I see a moon telescope as a much better use of tax dollars than the billions used for bombs and weapons for Ukraine. Most of the middle class homeowners in my neighborhood would agree. The middle class is not your enemy. Don't hate on the people who have managed to eke out something decent for themselves.
Barking up the wrong tree. Middle-class homeowners have no say in tax spending. I think you have some kind of political bias against people who own property, maybe out of envy.
@@chawk1637Ukraine isn't being sent money or new production, we are sending them old equipment and munitions that we are already paying to store, guard, and decommission. With some munitions we actually save money by giving them to Ukraine.
@@chimken6090 That's not true. There has been billions of dollars allocated to Ukraine, and while most of that has been military aid, a very significant fracrion has been financial aid. There is also humanitarian aid being given, but that sum is less significant. Even if we are gifting old property, as you imply, we still paid to produce it. And we could still sell it, as we often do with outdated military hardware. No matter how you try to phrase it, the aid we are giving Ukraine has a cost to taxpayers, and that cost is over 75 billion dollars.
@@chawk1637 That is true, but it's not like not giving Ukraine the aid will suddenly lighten your tax burden. Regardless of if we send equipment you have already paid for that equipment. You also pay for the aforementioned storage, guarding, and decommissioning of said equipment, so sending it to Ukraine quite literally saves you money. Nobody wants to buy the cluster bombs because they are outlawed by treaty (Russia has already used cluster munitions so the treaty no longer applies to Ukraine). As for the rest of the aid, we spend 801 billion dollars on the military each year, 220 billion of which the Pentagon was unable to account for. In the grand scheme of things, even 75 billion to Ukraine over the course of the war is helping us to beat our main geopolitical rival, defend a nation trying to align with the west, and get good PR for all of this. Also, the 75 billion you quoted is the total valuation of aid provided to Ukraine. Of that figure, 26.4 billion is financial aid which is mostly loans. That 26.4 billion is insignificant on the scale of the federal government and is almost guaranteed to have some return.
Hi Matt. I have a question. From the many-worlds interpretation of quantum mechanics we can say that we use other universes for practical application meaning we have access to other universes to extract information processing power in a quantum computing that is orders of magnitude faster than if we use a classical computing only in our universe(think infinite parallel computing). So my question is it possible to extract an energy/momentum from a parallel universes just like we use a quantum computing to extract information processing power. For example imagine if we can isolate a hydrogen atom and somehow observe the electron cloud so that at the moment of the observation the wave function collapses in higher orbit/higher energy state(the universe in which the electron is in high energy state) so that when the electron losses energy, when it drops into low orbit the emitted radiation can be thought of a work extracted from a parallel universe and repeat the cycle again so that our universe gains energy but one of the parallel universes losses energy. Is this or a similar work extraction from a parallel universe possible, either in the near or a distant future with a highly advanced technology. Long story short can we extract work/momentum from a parallel universe just like we extract an information processing power with a quantum computing from a parallel universe according to the many-worlds interpretation? Thank you.
You know there is a real proposal for something even outlandish than this. To use sun as a gravitational lens and place a HUUUUGE telescope somehwere around 300-500 AU. This would help us directly image exoplanets whenever they line up. There are a tpn of challenges to be solved especially with data communication but nothing physically impossible!!
This idea is probably the best idea ever created by man. It would make me cry if I had any tears left. I'm not surprised anymore that we could even conceive of such a contraption. Lol. Though, I'll probably cry when I hear that we actually did it.
Thank you to the Space Time writers for discussing the geometry correction in terms of carefully adjusted cable thickness, Real Engineering's discussion of carefully arrayed weight(s?) was much more confusing. Even though of course a thicker cable will also be slightly heavier. But thickness just intuitively clicks better.
So I love the channel, but I have to know how hard it is to write the Space Time sign off in every video. Its always something to look forward too. This one was very creative.
I think the best prospect of this is that if each array is only 1.5 to 2 tons, maybe multiple could be brought up in a single payload. We could haul up 3, if not 4+, and put them at very different points on the moon to achieve very different vantage points (also if one fails/crashes, we can still be happy with the other functional ones, not a total waste). Then, the orbiting relay could be put on a path to gather info from all of them as efficiently as possible. While looking into historic space is cool, continually looking at the rest of the Milky Way is equally important and the more eyes we have in space means the faster we learn in all directions! Plus, a moon telescope is just a dope idea.
I’m also not NASA but obviously this project is worth realising. Even just to test the technology of installing the mesh in a crater makes it worth it. I can inmagine similar tech could be used to build an instant crater base / shelter
Space Time is hiring new script researchers and new writers! Check out the latest community tab post for details and how to apply!
I would love to work Space Time. However, I don't have the background, experience, or talent to do so🙃. If you ever need a farm laborer...😅
Hire a sound guy.
In retrospect retrospect itself violates entropy
Wouldn't it be easier to put telescope on the moon then put Earth's atmosphere on the moon like in the Phineas and Ferb episode
Looks like that crop circle response to the Voyager
I don’t think it’s said enough that you are one of the best presenters and educators on UA-cam, Matt. Stellar work (pun intended)!
Absolutely agree.
Completely agree
I agree with 5 sigma of certainty!
The only one who compares is David Kipping from Cool Worlds.
@@silviavalentine3812 I'll see your 5 sigmas and raise you one... 6 sigmas of certainty.
I think it's a great idea. Something multiple space agencies should collaborate on.
This. Loudly absent was any talk of other groups trying this.
I was thinking the same thing... right away my brain went "what about a NASA-ESA collaboration?" because this is a gap in our understanding that really needs investigation.
Don't worry, USA will waste hundreds of billions sending arms to nazis and terrorists before spending a single cent on this. Science? Pfft, arms companies pay a lot to get their puppets elected, maybe if these dumb nerds cough up a few billions in bribes-- I mean PAC funds the congress will think about funding progress, too...
Collaboration is inefficient. Better let each agency focus on individual, big projects.
America won't work with Russia or China because America want to be the most powerful country in the world - like a complete arsehole would.
11:53 This animation is FANTASTIC. The expansion of the central disc area like the unfolding of an origami flower is just... chef's kiss.
origami maths for the win :)
Stupid
And then all that needs to happen is a single hook not catching anything for the proposers of this plan to look very silly and dumb, and you can't even send humans to fix it because no one will scale 200 meter tall cliff in space suit...
@WeavingBird
eg smithsonianmag theres-origami-revolution-industrial-design-180972019
(web links don't work in TY comments)
@@KuK137 I'm sure this well known failure mechanism will be taken into account in the design.
We need this if only so the next Bond movie can have a fight scene in a Lunar crater. That's what radio telescopes are for, right?
90’s kids understand this reference
"For Elon, James..."
*drops Sean Bean from the bottom, he sloooowly falls down*
@@TheDemigansbecause the fall wouldn’t be fatal, it could be the one role where his character lives
Moonraker + Goldeneye = Science
I’m thrilled for this, not only because bigger telescopes are better, but also because it’ll kickstart lunar development.
Build a lunar telescope as far from noisy primates as possible....
Kickstart lunar development by invading noisy primates.
The classic victim of its own success.
If only some space agency did kickstarters
@@TehJumpingJawa No. Machines will inherit the moon.
Yes. For this project, NASA/ESA would need a relay satellite in lunar orbit (or L2 as mentioned), but due to the telescope not being able to work when the sun shines on it, that relay satellite might face 50% of its time without work. NASA/ESA might therefore consider a something else to make use of that relay satellite.
Hands off the moon. Science only please.
Life is like a box of photons, you never know how warped it's gonna get.
Ngl I might steal that one.
Life gets warped? I've not heard that one before.
One can 'effectively' hope at least :)
So cool to get an episode on this from both real engineering and space time!
thats right lil buddy 😊
@@tuneboyz5634 you alright?
@@efhi yeah I'm good 😊
How are you? 🙂
I don't know what would be discovered, but I believe that it should be no surprise to anyone that there will be surprises.
Surely, there will be surprises on the Darkside of our moon.
@@ucheopara6309especially when the far side and dark side coincide :)
I'd love to see this happen. Building sky telescope on extraterrestrial sites around the solar system.
Thank you Matt and PBS Spacetime!
Firing all those harpoons in just the right way sounds like it has no chance of not going wrong. But then I said the same thing about that sky crane thing, so shows what I know.
Language time! The “e” in “Chang’e” is a schwa in the International Phonetic Alphabet; that is, the same vowel as in “uh” or “um” in most English accents. “Chang-uh”.
Bonus round! The “ch” in many Chinese words, including the name of the moon goddess, Chang’e, represents a very interesting consonant cluster. In the IPA, English “ch” is usually represented as two consonants articulated in succession, “t” and “ʃ”, typically represented as “sh” in English. In Chinese, there is an additional variant of “tʃ” which includes a retroflex fricative consonant, rendered as “ʂ” in IPA; in practice, this is a little like curling your tongue into the English “r” shape while pronouncing “tʃ”. This one probably requires a bit more practice for speakers of the various English dialects, and easier to sort of swallow outside of a Mandarin Chinese speaking environment compared to the “uh” vowel, which is both used in English and quite prominent in the word-final position.
(This is all for pronunciations in Mandarin Chinese, by the by, no idea how things shake out in Cantonese or any other of the various languages/dialects under the “Chinese” umbrella.)
When I was an undergrad I enjoyed this channel as entertainment, and now as a PhD candidate I think hmm should I devote the next five years of my life studying this
what have you learnt?
Great episode! Audio volume is kind of low, though.
Yes, very low.
Over compressed audio
I'm always so happy whenever I see a new PBS Space Time video in my feed.
Wooo new spacetime! Thanks Matt ❤
This feels like the digital equivalent of PBS slipping NASA a $20 bill with a sticky note that reads "please build that super cool radioscope on the moon :)"
11:00 it's the other way round: it has to be heavier at the center.
And to support the mesh better it is a good idea to have additional ropes between the main support strings (spider-web like) - this can also do the job to create the parabolic shape, because they would lessen the tension of the main ropes in the center.
Wouldn’t the telescope be vulnerable to asteroids from impact and the moon dust? How often do we expect a direct hit or a near miss?
The telescope will be very thin but strong thread, dust will mostly go through the holes. Larger pieces might punch through but won't make enough difference to degrade performance. A radio telescope does not have the same issues that an optical one does where impacts will damage the lens and diffract light.
Roughly 1 in 12 billion chance per day.
Assuming the timescale for this project is 25 years, it has a 1 in 1.3 million chance of getting hit by anything large enough to do meaningful damage.
EDIT: Sorry, you asked how often. About once every 25 million years.
@@Merennulli Sounds safer than driving to work or going to the toilet.
@@Mp57navy I don't want to say whether or not it's safer. I was just giving the chance of meaningful impact (which is lower for anything on Earth due to the atmosphere). But there are no other telescopes driving around to run into it, and the telescope won't take codeine before using the restroom.
But it has a lot more risks in getting there. And once it gets there, the intense solar radiation isn't doing it any favors for longevity. I also didn't answer the dust portion of the question because I don't actually know the answer on that. We have technology to deal with the electrostatically charged dust by using it to generate power and using that power to negate the charge. But I don't know if that technology is beyond the prototype phase yet. That said, they won't launch it if they don't have some dust management technology in place.
@Merennulli lmao who are you?
Sounds like Radio Shack is back in business, baby!
… I’ve always been impressed with the care you’ve taken in pronouncing foreign names, names of scientists, etc., and now the Latin feminine plural suffix, -ae, pronounced, just as my Latin teacher said! You’re doing much better than almost any biologist :-)
Always love a new episode!
All these years and this continues to be GREAT!
Matt carries an emergency pastry so he doesn't have to talk to fans.
Started off studying electronics in '73 and fell in love with physics. I had no idea we were so ignorant in astronomy at those frequencies, as soon as you set up the problem, it is like well duh, the ionosphere. wow and a whole new data set for sky guys ...
This is so cool-I've been a fan of this idea since reading an Arthur C. Clarke story where it was done with a spinning pool of mercury, but I never thought they'd figure out a way to do it with just a single incredibly clever deployable probe. The most obvious objection is whether all the harpoons will find purchase and not glance off a boulder or pomf into a big mound of dust, but maybe robotic piledriving is more advanced than I realize or it can be designed in a way where it doesn't need every single wire to maintain its shape-Or if it's a self-contained probe maybe we can Voyager it and build a few of them so at least one is likely to get them all in. Either way it seems like a fantastic idea for a first look, and if it uncovers the iceberg tips of some exciting cosmic mysteries it can be followed up one day with an actual facility.
Thank you Matt and PBS Spacetime!. Great episode! Audio volume is kind of low, though..
Surely the greatest discovery from this project will be the Monolith we discover in the side wall of the crater.
Just make sure you mute your TV when we do.
Always love watching your videos - and this is probably the only one I’ve understood 100%!!
Would love to see (actually won’t see it!) a telescope like this up and running - we can only imagine what we find…
Also, your graphics team absolutely nailed it this episode
Varying the thickness to change the caternary into a parabola shape is so genius and yet so simple I'm amazed previous proposals hadn't thought of it before
That is such a cool idea! I love the fact we are considering lots of ways to gather data of any/all kinds. It's easy to understand the budget restrictions and whatnot, such as extremely great ideas just too expensive and although likely to be incredible, it's just too risky or costly.... I wonder if it's been considered to put a relatively large number of small antenna type dishes over the surface and use the quantity over large areas that are linked in something like an ad-hoc network maybe in separate clusters of antenna that link up then that information is relayed over larger repeater dishes or network to the side of the moon we can receive proper communication from so that data speeds should be able to keep up with the incoming information much more effectively and less delay I would think. Can't wait to see what's next! Great video! 🍻🌎❤️🎶🕺🚀
@@nadsenoj8719 I gotcha... I figured it was close to something already considered and all... but hey, it's fun trying to figure all this stuff out! Have a great day/evening! 🍻
Small dishes will be unusable at the long wavelengths expected from that far away. Instead, an array of wire antennas such as used at the Long Wavelength Array, New Mexico (256 antennas) or LOFAR across Europe (12000 antennas) would achieve astounding sensitivity on the Moon.
@@witwisniewski2280 that's more of what I was thinking but maybe start with smaller clusters and scale upwards when viable... I'm sure someone will come up with something awesome and crazy and probably 10x better anyways lol just fun to think about 😁 Enjoy your evening!
So cool ! A new video from Don @ Fermilab and "PBS Space Time", on the same day !
0:00: 🌑 A giant radio telescope on the far side of the moon could allow astronomers to see further back in time than ever before.
3:40: 🌌 The lunar crater radio telescope could provide a glimpse into the cosmic dark ages and help understand the early universe.
6:51: 📡 The video discusses the importance of a giant space radio telescope on the moon for detecting and studying radio waves.
9:48: 🌕 The Lunar Crater Radio Telescope (LCRT) is a proposed fixed-dish radio telescope on the moon that uses a unique hanging design.
12:49: 🌌 NASA is considering turning the far side of the moon into a giant radio telescope to peer into the time before stars at the beginning of space time.
16:07: 🌌 Dark matter can potentially diminish over a long timescale, causing galaxies to fall apart.
18:34: 📺 The video discusses the random nature of particles and how they can affect spacetime.
Recap by Tammy AI
A VERY INTERESTING & EXCITING PROJECT LET'S DO IT ! ! !👍
If we ever had a plausible excuse for a "moonbase" or a moon colony, then building & operating this telescope just might be it!
thanks for the information
one thing i should point out both the moon and mars are going to need a dedicated communications net. having long communication blackouts will really not be acceptable in the long run
Some combination of communication relay sats at Lagrange points and synchronous orbits may be a useful investment. We should be able to get the internet on the Moon and Mars using existing tech. JWST needs a better radio link too!
When Matt explains the redshifting of the CMB for the 100th but you remember that the first rule of teaching something is repetition 🧑🔬
10:53 catenary! i used to work with those all the time when doing EM field studies on high power transmission lines. line tension and weight are your two variables iirc, plus temperature sag. (whoa, changing the thickness of the line to change the shape of the curve, that's rad)
A Super Arecibo Observatory, yes, please can we also have a Mega Gran Telescopio Canarias as well. Great video, as always.
Rest in peace, Aricibo, maybe we could name the one on the moon after you?
@@delwoodbarkerBricibo
Arecibo II
(but pronounce it ay ay!) lol
If Artemis actually goes as planned and SpaceX SuperHeavy development goes as planned, such a project may very soon become not only possible, but also not astronomically expensive to actually happen.
Looks interesting
I've always had the picture in my head that we should have a telescope orbiting Neptune and Jupiter. Relays at Saturn, Mars and the Moon. That would give us the most optimal view distances and would be a testament to our engineering feats. Yes, it would be way more challenging to upgrade them in the future, but at the same time, it would give us invaluable insights.
earth and the sun are still the brightest radio objects around - and the only place where you are guaranteed to avoid the earth is the far side of the moon. You don't get too much extra by going further out. And Jupiter (with its massive magnetic + radiation field) isn't an amazing place for telescopes :)
Further out just merges the radio noise from sun and earth into similar parts of the sky.
@@andytroo That is a VERY fair reason for why we haven't done it with our more advanced tech. I would still love to see what type of visuals we would get with a lens telescope that sent images back to us from that distance though. I'd imagine the view of the inner planets would be quite spectacular.
It's funny. When you consider the entirety of _all_ UA-cam viewers watching _all_ the different videos available on UA-cam, the majority of viewers probably want to meet movie stars and "influencers"... In contrast, I'm jazzed that I was able to attend in person (on two different occasions) lectures by Roger Penrose. And I would love to meet Matt O'Dowd and other physicists. These kinds of people are *my* heroes!
😎👍
IMAGINE an alien civilization beaming radio signals at us for contact but never knowing about the ionosphere...
If we have one, so do they.
They know about it.
I think rather than not knowing about the ionosphere, they're just patiently waiting for the possibility we prove ourselves "worthy" enough to hear the message by leaving the cradle.
Radio noisy primates!
Up and down the dial, it's all flung.
@@JesusFriedChrist What if they know about it and send it in a way that only sufficiently competent and developed civilizations can receive? IE ones spending on pure research/scientific projects, not just arms race in space?
@@JesusFriedChrist you're assuming that extraterrestrial life will be earthlike, from an earthlike planet.
one thing we know life can do is "eat" radiation to live. it's a rare thing here on earth, but it does happen. imagine, if you will, a planet with no ionosphere where radiotrophic life evolves to be the dominant form. intelligent life from this stock would probably make the same mistake you just did, and assume any life they find will be radiotrophic, from a world with no ionosphere. therefore, they'd send signals that would bounce off of our ionosphere.
When Starship + Booster get going missions like this would be at most two flights for what is needed to build things like this.
Bring a few Tesla Bots along for general purpose contruction and maintenance. Nice!
Imagine if the science budget for the world was large enough that humanity could do something like this just 'because'.
We should never be putting things on the moon "just because". Space should be treated as or better than we treat national parks and rainforests. Carefully. Very carefully.
@SolidSiren there are no ecosystems to destroy on the moon though, so why not?
@@SolidSiren To be blunt. The only things alive on the moon are when humans do things. Industries and science programs can be put there with no ill effects on Earth.
Unless you don't know the difference?
Love the ET lurking besides Matt's right ear eg 04:34... nice joke by the team.
I've always wondered why there wasn't already a radio telescope there
Yeah I've always wondered why things cost money
RIP Arecibo. Still not over it.
Have any moon orbiting space craft trained their radio band antennas towards deep space while on the dark side? Or have their orbits precluded that.
The antennae on spacecraft are way too small for the wavelengths of interest.
No, there's generally not been many that orbit the moon and they've had poor resolution since none were especially designed to pick up generic radio signals. They were all built for other things.
i hope i am still kicking when they made this. Godspeed and good luck to the engineers.
I've always been confused about the red shifting of light. I understand (mostly) the concept, but my question is, does light get red shifted all the way down to nonexistence or is there a remnant of some sort? energy and/or mass just doesn't stop existing, right? Can light that has lost nearly all of its energy change from its wave/particle duality into something below the known spectrum?
Ooooooh that's a really good question and now I must know
As far as I understand (not a professional), it can only asymptotically approach zero frequency or exponentially approach infinite wavelength. It never truly disappears. Only in the case of a black hole would it even be a question, because even the farthest reaching photons from across the cosmos are "only" stretched by a factor of a million or so. But in black holes, it's not red shift that swallows the photons, it's just the fact that all geodesic paths inside the event horizon lead to the singularity. There's no escape route, red shifted or otherwise. Although during the process of falling in, you can have photons that are emitted from near the horizon that are extremely red shifted due to the time dilation. So there's a limit as you approach the horizon where photons from a source there would approach infinite wavelength. Of course that would make their exact position highly indeterminate. And it would blend in to the Hawking radiation from the black hole as the wavelength reached the size of the BH itself, in practice becoming undetectable via any instruments available.
Also bear in mind, the law of conservation of energy does not apply to cosmic inflation, as the underlying symmetry is broken on that kind of scale. There was an episode of Science Asylum about that. I'm not sure how to explain the red shift due to gravity of General Relativity in those terms though.
In th4e case of gravitational redshift, mass\energy is conserved. A photon escaping a gravity well is equivalent to a tiny rocket, pushing itself up by ejecting something behind it. The energy lost by the photon is kept by the massive object.
Any observable photon will never be redshifted to nothing, that's not physically possible. The ones we think of at doing so will either be trapped on the event horizon of a black hole or fall into it.
On a cosmic scale it's a bit more tricky. Traditional energy is not conserved, but something more broad, involving the 'energy-momentum four vector' IS. There too a photon cannot be redshifted into nothing, there must always be something remaining since a real particle cannot just cease existence.
Great video as always Matt, have you done a video on/are there any proposals for, the building of a rotating ring orbital station to allow longer term stays in orbit?
I’m beginning to think that Isaac Arthur was onto something when he said, and I’m paraphrasing:
”Give NASA the budget to build a lunar colony, and you’ll end up with a lunar telescope instead.”
This is why we need a space development agency, lol.
Why do I press the like button even before the video started? Force of habit on PBS Spacetime.
Boy do I sure hope they figure out a viable way to make this.
The concept was enough to convince me. Let's do it!
I wish I were a billionaire so I could give NASA the money they need for the project
They already have the money; they need a wake up call
@@TigburtJones They do? 🤔
* Pokes NASA with a stick *
C'mon.... Build the dish.
7:09 photon size when the universe was 17 years old, missed it by just a few orders of magnitude guys 😋
17 - that might be when the universe was old enough to have a ham radio license...
Antenna array telescopes are vastly more flexible than dishes. The modern array digitizes the actual wavefront over some large area, essentially receiving all incident radio waves at once. Numerical processing then selects a direction or beam to look with, numerically focusing on an object. Multiple beams in diverse directions can be observed at the same time and each beam is instantly steerable. The limitation is data bandwidth for conveying the wavefront to the computers, and the processing bandwidth of the computers themselves.
Matt, don’t forget the 20Mz noise from Jupiter - an HF radio wave can penetrate the ionosphere if the angle is correct, it doesn’t always bounce off into space.
Yeah, HF radio waves interact with the ionosphere in deeply strange and unpredictable ways, depending largely on space weather. Sometimes that 20MHz can come right in, sometimes it bounces off, on rare occasions it comes in and then bounces around inside the ionosphere and makes a real hash of the 15M band.
I prefer wide array of dipole antenna to parabolic mesh dish. Dipole antenna can be steerable like AESA radar to observe whole sky.
And it can be deployed gradually over long time. First with few antenna, next 10's of antenna and finally 100's of antenna on moon's surface.
The antenna can be scattered over very wide area like few km-10 km per antenna and used as long base line interferometry
telescope array, which will improve spatial resolution greatly.
Sounds like an exponentially more costly project
If they do this, I think the crater it ends up in should be called Arecibo Crater in memory of the late giant. Then we get an Arecibo telescope back again :)
Quite great to get a episode from Space Time for sure.
Are you a bot?
@@TheTuttle99 Bots most be getting smarter these days if so.
Man if the world was at peace we could discover so much more within a human lifetime!
Isn't this the truth, but some people would rather have a yacht than progression for others.
Yes. We should do this.
👇*sips tea and enjoys a new episode button*
You had me at space hammock...
I am cool with using my tax dollars for a moon telescope, but the middle-class homeowners are just going to say we need that money for more bombs and weapon's.
Hey there. I'm a middle class homeowner and I see a moon telescope as a much better use of tax dollars than the billions used for bombs and weapons for Ukraine. Most of the middle class homeowners in my neighborhood would agree.
The middle class is not your enemy. Don't hate on the people who have managed to eke out something decent for themselves.
Barking up the wrong tree. Middle-class homeowners have no say in tax spending.
I think you have some kind of political bias against people who own property, maybe out of envy.
@@chawk1637Ukraine isn't being sent money or new production, we are sending them old equipment and munitions that we are already paying to store, guard, and decommission. With some munitions we actually save money by giving them to Ukraine.
@@chimken6090 That's not true. There has been billions of dollars allocated to Ukraine, and while most of that has been military aid, a very significant fracrion has been financial aid. There is also humanitarian aid being given, but that sum is less significant.
Even if we are gifting old property, as you imply, we still paid to produce it. And we could still sell it, as we often do with outdated military hardware.
No matter how you try to phrase it, the aid we are giving Ukraine has a cost to taxpayers, and that cost is over 75 billion dollars.
@@chawk1637 That is true, but it's not like not giving Ukraine the aid will suddenly lighten your tax burden. Regardless of if we send equipment you have already paid for that equipment. You also pay for the aforementioned storage, guarding, and decommissioning of said equipment, so sending it to Ukraine quite literally saves you money. Nobody wants to buy the cluster bombs because they are outlawed by treaty (Russia has already used cluster munitions so the treaty no longer applies to Ukraine). As for the rest of the aid, we spend 801 billion dollars on the military each year, 220 billion of which the Pentagon was unable to account for. In the grand scheme of things, even 75 billion to Ukraine over the course of the war is helping us to beat our main geopolitical rival, defend a nation trying to align with the west, and get good PR for all of this.
Also, the 75 billion you quoted is the total valuation of aid provided to Ukraine. Of that figure, 26.4 billion is financial aid which is mostly loans. That 26.4 billion is insignificant on the scale of the federal government and is almost guaranteed to have some return.
This idea sound really cool!
Matt seems like the coolest professor.
I'd love this, mainly because it kicks ass.
Would love a "PBS spacetime/Matt reacts to Startfield" video! And/or other similar Sci-Fi analysis videos would be HUGE and fun!!
Hi Matt. I have a question.
From the many-worlds interpretation of quantum mechanics we can say that we use other universes for practical application meaning we have access to other universes to extract information processing power in a quantum computing that is orders of magnitude faster than if we use a classical computing only in our universe(think infinite parallel computing). So my question is it possible to extract an energy/momentum from a parallel universes just like we use a quantum computing to extract information processing power. For example imagine if we can isolate a hydrogen atom and somehow observe the electron cloud so that at the moment of the observation the wave function collapses in higher orbit/higher energy state(the universe in which the electron is in high energy state) so that when the electron losses energy, when it drops into low orbit the emitted radiation can be thought of a work extracted from a parallel universe and repeat the cycle again so that our universe gains energy but one of the parallel universes losses energy. Is this or a similar work extraction from a parallel universe possible, either in the near or a distant future with a highly advanced technology. Long story short can we extract work/momentum from a parallel universe just like we extract an information processing power with a quantum computing from a parallel universe according to the many-worlds interpretation?
Thank you.
I wish they'd put Matt in the thumbnail... love this guy! Always click when I see him!
Aracibo collapsed ? BUMMER !
Love this page. Your topics and the information guven is awesome. Helped me understand several topics.
Human creativity is truly out of this world 🌗
It literally isn't
You know there is a real proposal for something even outlandish than this. To use sun as a gravitational lens and place a HUUUUGE telescope somehwere around 300-500 AU. This would help us directly image exoplanets whenever they line up. There are a tpn of challenges to be solved especially with data communication but nothing physically impossible!!
This idea is probably the best idea ever created by man. It would make me cry if I had any tears left. I'm not surprised anymore that we could even conceive of such a contraption.
Lol. Though, I'll probably cry when I hear that we actually did it.
Thank you to the Space Time writers for discussing the geometry correction in terms of carefully adjusted cable thickness, Real Engineering's discussion of carefully arrayed weight(s?) was much more confusing. Even though of course a thicker cable will also be slightly heavier. But thickness just intuitively clicks better.
LMAO Matt, that last one man, cracked me up.
Almost every other thing I watch on UA-cam is really just a distraction while waiting for a new space time episode to drop.
The industrial production of the construction drone and Starship will make many dreams come true.
So I love the channel, but I have to know how hard it is to write the Space Time sign off in every video. Its always something to look forward too. This one was very creative.
what an incredible video
................ Space Time.
Thanks folks, another great episode. =)
I'd love to see a video about the Solar Gravitational Lens Observatory next.
Real engineering vs PBS space time, game on.
Edit : your take on it is better (as expected)
Next project: building the 11 Megameter Lunar Circumference Particle Accelerator.
idk if it's just me, or has science become more popular in the past 2-3 years? i'm all for it!
Had some trouble with catenary, did you Matt?
I think the best prospect of this is that if each array is only 1.5 to 2 tons, maybe multiple could be brought up in a single payload. We could haul up 3, if not 4+, and put them at very different points on the moon to achieve very different vantage points (also if one fails/crashes, we can still be happy with the other functional ones, not a total waste). Then, the orbiting relay could be put on a path to gather info from all of them as efficiently as possible.
While looking into historic space is cool, continually looking at the rest of the Milky Way is equally important and the more eyes we have in space means the faster we learn in all directions! Plus, a moon telescope is just a dope idea.
Wicked cool episode, bud!
I’m also not NASA but obviously this project is worth realising. Even just to test the technology of installing the mesh in a crater makes it worth it. I can inmagine similar tech could be used to build an instant crater base / shelter
That would be fascinating.
Let's build it!