this vids kicked ass. asked really good questions and got good closeup shots. thanks for interviewing this guy! Nobel Laureate John Mather visited out school and at one point mentioned adaptive optics and how it was classified in the us but later recreated in france where the technology was then distributed...
it's a great idea to change the shape of the mirror in accordance with the atmosphere. this is a simple but very powerful method for viewing distant galaxies
It'll be great when the deformable mirrors get affordable to amateur astronomers. For now, wave front sensors require guide stars but I wonder if a wavefront sensor could ever work on assuming some stability in the undistorted image like speckle imaging does. Requiring a powerful laser will always be a deal breaker for amataurs. If the wavefront could be detected and given to an affordable deformable mirror, amateur astronomers could finally see lots of detail.
That's very close to to setting the "mode" on a beam through a particle accelerator, difference is that the ''deformal'' mirrors on the last resonator I set up were manually set and liquid cooled. But when we set the mode we were always looking for a "O" as the footprint not a circular dot because the assist gas needs to follow the wave front when cutting and the particle beam would burn the mirrors and lenses and end up warping them or melting them if the beam became concentrated before leaving the final focal point lens of the head. The resonator would cost upwards of 150k which consisted of 1 output-mirror(first pooiont at which the mode could be measured), One Rear mirror and 6 bending mirrors with correcting centers which all surround the turbine pressure generator for the plasma gas containment. The beam was bent 6 times before leaving the resonator for maximum particle accuracy. Every change in direction of the beam that is made before leaving through the output mirror makes the particles travel more and more straight. If there were only an output and a rear how many tines would the light bounce between the two mirrors before reaching the output mirrors resistance level? Baseicaly you get a output beam of peak performance just outside the resonator but 100 feet away the beem is no longer optimal because of widening like a laser pointer. With all the other bending mirrors in the resonator there is that much more correctability and trueness to the output beam. If we had liquid cooled "deformal" mirrors that would be the cats ass. For telescopic use; can the curvature of the Earth's atmospheric surface not be worked into the calibration as well as smooth the and even the wave front? And as well can we use a second and even perhaps a third or fourth highly sensitive "deformal" mirror or even mirror array for digital adjustment of magnification and ? zoom ? ...this implemented into both systems of focusing visual ability and the focus of particle acceleration to a completely new level of accuracy? This is truly the next step in the weaponization and optical observation. With this type of setup it would be possible to correct the existence of interference particles between the output mirror and the target by an automated (sensor/programmed controller/servo-adjusted/correction-checking/loop) setup that would allow the beam (or image to be viewed) to be bent around minor interferences that otherwise distort the focus of the image (or output beam). One would think that with what we already know in means of technology we should be able to assemble an apparatus with ability to see a mouse on thee back side of Pluto and focus a particle beam to neuter him too. As well the same technology with proper calibration could be used to measure the distances between us and anything or the distance between any two points in the universe we can see. The same technology can again be employed to deliver energy wirelessly to a space faring vehicle as propulsory fuel. Further more I here present that geothermal energy sources throughout the solar system and other energy sources could be utilized to extend the range of said space faring vehicles by installation of energy beam emitting stations that would operate autonomously by receiving pings like a cellular phone network then once the ping is received the network would use the closest tower to beam propulsory energy to the vehicle. This technology after final development and thorough refinement could also be used to autonomously explore, scout, and expand our travelling range while constantly sending a report of progress back to us so we know what to expect and where to expect it in space exploration. It would be used as a research refinement tool so we would know where to and not to find whatever it is we may be looking for and it could also be made untraceable to such an extent that it would in its tamper proofing be made to report its origin as its direction of exploration or as any where we want to make tracing of its origins impossible for an alien race that may discover it and investigate it. A decoy could be also made at the reporting place of origin to allow us to monitor the reaction of the alien species to our existence. As well other measures could also be taken... An autonomous space fence could be employed within the very same network to defend our territory from outside aggressors by making the propulsory fuel delivery system adjustable to a weapon grade beam devise and as well kinetic weapons systems could also be installed to further backup these autonomous beam stations. The exploration units could be designed to work completely around any life form it found so as not to encroach on its natural self set boundary as well since all space is designated free for development of non space faring, non threat localized natural wild life throughout the universe. Only species with sentient ability to destroy everything and overrun other types of life in the universe in an aggressive manor need limitation by universal law because from the general sentient beings curiosity fulfillment need of an explorer and respecter of the universe is come the Universal living beings right to happily exist naturally just so more diverse things are out in the universe for ever to be seen and experienced by all space farers because once there is nothing left to discover and nothing left to invent and the only driving factor left to us becomes need of resource to maintain and everything has been cataloged and learned we will become pretty bored if we have to look at the same thing everywhere. Travel and diverse leisure activities will inevitably become the focus of our existence. Can't wait.
8 лет назад+1
Thanks Mr. Andersen 4 this brilliant class. I want more technical information about. 4 ex. in the secondary mirror (or other intermediary), how mutch must be the distortion of the surface? Other: It's possible to use the electrostrictives property of quartz about? (to build the secondary or some terciary mirror) So you needs not more than small silvered surfaces connected to computer, like a net I want your FB friendship, to ask more.
One question: why does it have to be so expensive? If one would mass-produce it, it could be in the range of amateur-astronomers worldwide. It would be a vast market-opportunity...
Yea mass produce 3 m miror with sensitive elektronic instruments. Even amator telescopes do not sell that much and those are mostly build with 200 to 300 mm miror. It cost 1 or 2k dolar if you are getting a good decent one now apply on that price 10k more just for hardware and you need to be really tecnical to use it. Now how many people will need that to massproduce.
@@cemoguz2786 obviously, I meant a miniature version, not one for a 3m telescope. ;-) The same (counter)argument you are using has also been used in the past with computers as well. They used to be massive, spanning a room, and costing 500000 dollars. Back then, there was no vision of a possible "mass market" neither. In fact, Thomas Watson, president of IBM, notoriously said "I think there is a world market for maybe five computers." Well... we all know how badly that claim aged, don't we? Nowadays, thanks to miniaturization and mass-production, we can buy a decent computer for 500 bucks, and they're small enough to put in your pocket. Yes, for a thousand times less money and a hundred times smaller, and that within a few decades. My point was: one should go the same route with adaptive optics. Yes, if you make prototypes for 3-10m mirrors, it will be both massive and expensive. But just like with the computers of old, if you miniaturize and mass-produce it, it will be a huge success as well. Once it only costs 500 dollar and can be used with even a 25cm mirror, I bet almost all serious amateur-astronomers would buy one.
I found this extremely interesting. My knowledge of optics is mostly limited to the material covered in the optician course, and even then there were parts of it that I memorized without really understanding. I think you've inspired to me make some videos on the optics of glasses -- which I will probably run by you to make sure that the math parts aren't screwy :)
"I would like to hear more about how the correction analysis itself takes place." I'd like to know this, too. Are they comparing the current image to the deviations observed in the point light source? There is only a foot of atmosphere between the point light source and the detector, but there are miles of atmosphere between Jupiter and the detector, so I don't see how a direct comparison can be made. Also, the wiki page doesn't really get down in the nitty-gritty details, which is what I'd like to see.
david21686 With our table top experiment we used a 'synthetic' atmosphere. That glass disc at 7:15 looks perfectly clear, but it's actually distorting the light from the laser into that wavy patern you see on the science camera at the end
Great video! But I have a question though. Why have a physical shape shifting mirror? Wouldn't be much easier and faster to have a program that grabs the reflected image, calculates the distortion and generate an image on the screen with a corrected image?
Well I think the science fiction software programs from CSI or other films where they can resharpen a blurry image to toal crispness are just that... plain science fiction. (well, ok, at least to a certain amount, because there are real applications indeed). The problem is, that if the image is already taken, you cannot determine from where a photon came from any more. You have only a 2-D representation of a 3-D input. The third dimension is lost and can only be predicted to a certain amount. That's why the photons have to be guided to the goal before they are captured.
MrVankog Thanks for your reply. I see your point. But It might be not that far fetched. There is a commercial camera called Lytro, that's capable of focusing the image after the shot is taken. I'm not sure how it works, but what it supposedly does (if I understood it correctly) is that it breaks the main image with an array of "microlenses" over an image capture sensor (not exactly a camera) and in the end the algorithm figures out where the light is coming from, and then it focus the image. This technology is available since 2009 and I guess it wouldn't be very complicated to adapt it to astronomical observations. And even if the processing takes some minutes, you usually don't need a "live stream" to observe stars. So what it basically should do, is to record the 3-D input and then process it after the information is captured. The advantage would be the cost and also don't rely in mechanical piezoelectric mirrors, that I guess can be a problem for resolution. I have no idea if it would be doable, and I guess there are much smarter people than me thinking about it already. But I have a gut feeling that it would be possible, maybe not with current technology but I wouldn't classify it as SciFy. en.wikipedia.org/wiki/Lytro
Nix Dorf You are right. I heard of this too. However, I think the main point with the solution in this video is to stay as compatible as possible to existing telescopes by just adjusting the mirror instead of the hole sensor and machinery. What you are talking about is a whole new approach for new telescope technology. Maybe we will see something like that in the near future.
MrVankog That seems pretty spot on about the direction of the photons being important. I've actually played with a Lytro it's quite a cool toy, but I don't know how they record the 3-D input. It could be as sloppy as taking multiple images with different focal points. I have a feeling the Lytro is probably not the most efficient when it comes to capturing photons, thus making the image dimmer. Not a problem for a daytime shot of your friends at the beach, but astronomical objects often need all the light they can get. Adaptive optics can be better at catching every spare photon, especially with a guide star. Again: I don't know how a Lytro works, but my suspicion is that it sacrifices brightness in trade for having the direction of the incoming light.
I think the most direct answer is because the computational load required to do this is actually quite large, and when you are trying to keep up with the rate at which the atmosphere is changing this is probably just too hard to do. Cool thinking though.
Wow, I would like to hear more about how the correction analysis itself takes place. And It seems like it always analyzes the current image/frame and applies the found corrections (retrieved via magic) to the mirror, right? So this means, because the atmosphere is constantly changing, the image cannot be perfect, because the correction measurements from the current frame _n_ are applied the the upcoming frame _n+1_ that possibly has already totally different atmospheric deviations.
It sounds like the main way the try to deal with the n+1 problem is by increasing the frame rate, which limits how sub-optimal the correction can be. It is possible to create sensors that would give you enough physical information about the incoming light to do the correction digitally (I think they are called 4-D sensors), but I'm guessing the cost is still too high to build a telescope out of them. *EDIT* Double post removed. No idea how that happened.
MrVankog You have to remember that air is still fluid, it changes densities as warm air rises and cold air takes its place, this is a pattern that can be predicted and captured as information using this lens. This information goes through computer chips which use algorithms with many variables that can be adjusted to predict this flow and bring up a sharper image over time. Believe it or not, a computer does more than 1000 calculations a second already, it can easily adjust each lens and predict how the air will change as it is doing it. The constant feedback from the camera that shows the images in the grid allows it do adapt as conditions change in its prediction.The only downside which you've pointed out is that the first image will not be sharp, but as each image is taken the computer can adjust each actuator in the lens to make it sharp.
+Diego C. I'm not an expert but here's my thoughts. I think the lag is kept under 1ms to minimize the effect. You might think that reacting to a 1ms future prediction of the wavefront distortion would improve things but it may be too difficult to accurately predict. I'm interested to see what an expert would say on this.
It doesn't. The correction isn't perfect, but you try to keep the update rate considerably faster than the atmospheric changes so that it doesn't matter too much. It's like when you drive a car. You see the car start to deviate from the center of your lane, so you adjust the steering wheel to put it back near the center. Your tracking always lags and is never perfect, but it is good enough to keep the car on the road.
@@twistedyogert quantum computers are practically useless right now and progressing quite slowly. The sensors and conventional computers will likely get good enough to either reduce that lag to microseconds instead of 1ms or make a useful prediction before quantum computers become useful for adaptive optics. 1ms is long enough for a 1GHz CPU clock to run a million cycles and that could be a lot of calculation so I doubt computer processing speed is the main bottleneck anyway.
Dudy Karl Don't know any off the top of my head, but I imagine any optics company would carry something like it. Or at least they should be able to direct you to one that does have them.
Just love to see science at work. Curious to the computer and program used that can analyze the light and get the mirror to adjust as fast as the atmosphere changes. As said 1000 times per second would take some serious processing.Depending on the amount of light particles it is analyzing at any time. Oh does it do it's calculations per particle or per pixel?
In this set up I think it had to do the calculation for each lens in the grid that was held up to the light. (the waveform thingy ) So maybe a few thousand inputs were needed for the computer to do it's thing.
This is a big issue with modern AO systems and a lot of time and money goes into solving the huge computational loads when trying to keep up with the atmosphere. This problem inherently gets worse when you increase the number of actuators (and thus lenses in the wave front sensor), which we do to get an even better correction.
I imagine a system of recognition type software could be employed much like facial recognition but with obvious parameter changes to automate the adaptability.??
Have we just simply looked over BCI solutions? Piezoelectricity arrays like the ones used for telescope correctional lenses may be a BCI solution because pressure or sound waves may also be present in neuron activity according to Thomas Heimburg from the Niels Bohr Institute at Copenhagen University and Andrew D. Jackson, who is an expert in theoretical physics. For now BCI electrodes scar over and it is not a lasting solution. So, is solving the problem of sustainable BCI as simple as looking at the problem differently with already existing equipment. Has anyone during brain surgery tried using piezoelectric stimulation on the brain during surgery? Keep in mind, pun, sound focused stimulation to mouse nerves to move their tales has already been done. Looks like it is worth the added 30 seconds in a brain surgery to explore this question, and see if sound is a feasible BCI alternative
so the atmosphere acts like water like when you're looking down at a fish it's all wobbly and distorted, does it also do that light refracting gimmick or is it too thin? i hope someone makes some damn high tech future sunglasses to fix that to make bow fishing easier cuz i wanna try, also wanna try using a harpoon or spear.
I always use the water/fish bowl example when talking about the atmosphere in demos! The light being refracted by a hot 'pocket' of air is different from a cold 'pocket' in the exact same sense that the light you see in air (above water) refracts differently from the light you see below the water. All materials have different indexes of refraction. Also I agree about the fishing thing, badass!
This explains it wonderfully! The explanation of how the mirrors work is something we always wondered about. Nice job.
Really interesting...and well explained by Masen.
this vids kicked ass. asked really good questions and got good closeup shots. thanks for interviewing this guy! Nobel Laureate John Mather visited out school and at one point mentioned adaptive optics and how it was classified in the us but later recreated in france where the technology was then distributed...
Really cool video. I hope you continue to make more.
Very good video. Deserves more views. I'll spread the word around (to my students ;)
Awesome presentation!
Wow, excellent video. This is insanely cool.
it's a great idea to change the shape of the mirror in accordance with the atmosphere. this is a simple but very powerful method for viewing distant galaxies
Do the mirrors wear out after awhile?
Great video!
Nicely done. Thanks.
It'll be great when the deformable mirrors get affordable to amateur astronomers. For now, wave front sensors require guide stars but I wonder if a wavefront sensor could ever work on assuming some stability in the undistorted image like speckle imaging does. Requiring a powerful laser will always be a deal breaker for amataurs. If the wavefront could be detected and given to an affordable deformable mirror, amateur astronomers could finally see lots of detail.
That's very close to to setting the "mode" on a beam through a particle accelerator, difference is that the ''deformal'' mirrors on the last resonator I set up were manually set and liquid cooled. But when we set the mode we were always looking for a "O" as the footprint not a circular dot because the assist gas needs to follow the wave front when cutting and the particle beam would burn the mirrors and lenses and end up warping them or melting them if the beam became concentrated before leaving the final focal point lens of the head. The resonator would cost upwards of 150k which consisted of 1 output-mirror(first pooiont at which the mode could be measured), One Rear mirror and 6 bending mirrors with correcting centers which all surround the turbine pressure generator for the plasma gas containment. The beam was bent 6 times before leaving the resonator for maximum particle accuracy. Every change in direction of the beam that is made before leaving through the output mirror makes the particles travel more and more straight. If there were only an output and a rear how many tines would the light bounce between the two mirrors before reaching the output mirrors resistance level? Baseicaly you get a output beam of peak performance just outside the resonator but 100 feet away the beem is no longer optimal because of widening like a laser pointer. With all the other bending mirrors in the resonator there is that much more correctability and trueness to the output beam. If we had liquid cooled "deformal" mirrors that would be the cats ass. For telescopic use; can the curvature of the Earth's atmospheric surface not be worked into the calibration as well as smooth the and even the wave front? And as well can we use a second and even perhaps a third or fourth highly sensitive "deformal" mirror or even mirror array for digital adjustment of magnification and ? zoom ? ...this implemented into both systems of focusing visual ability and the focus of particle acceleration to a completely new level of accuracy? This is truly the next step in the weaponization and optical observation. With this type of setup it would be possible to correct the existence of interference particles between the output mirror and the target by an automated (sensor/programmed controller/servo-adjusted/correction-checking/loop) setup that would allow the beam (or image to be viewed) to be bent around minor interferences that otherwise distort the focus of the image (or output beam). One would think that with what we already know in means of technology we should be able to assemble an apparatus with ability to see a mouse on thee back side of Pluto and focus a particle beam to neuter him too. As well the same technology with proper calibration could be used to measure the distances between us and anything or the distance between any two points in the universe we can see. The same technology can again be employed to deliver energy wirelessly to a space faring vehicle as propulsory fuel. Further more I here present that geothermal energy sources throughout the solar system and other energy sources could be utilized to extend the range of said space faring vehicles by installation of energy beam emitting stations that would operate autonomously by receiving pings like a cellular phone network then once the ping is received the network would use the closest tower to beam propulsory energy to the vehicle. This technology after final development and thorough refinement could also be used to autonomously explore, scout, and expand our travelling range while constantly sending a report of progress back to us so we know what to expect and where to expect it in space exploration. It would be used as a research refinement tool so we would know where to and not to find whatever it is we may be looking for and it could also be made untraceable to such an extent that it would in its tamper proofing be made to report its origin as its direction of exploration or as any where we want to make tracing of its origins impossible for an alien race that may discover it and investigate it. A decoy could be also made at the reporting place of origin to allow us to monitor the reaction of the alien species to our existence. As well other measures could also be taken... An autonomous space fence could be employed within the very same network to defend our territory from outside aggressors by making the propulsory fuel delivery system adjustable to a weapon grade beam devise and as well kinetic weapons systems could also be installed to further backup these autonomous beam stations. The exploration units could be designed to work completely around any life form it found so as not to encroach on its natural self set boundary as well since all space is designated free for development of non space faring, non threat localized natural wild life throughout the universe. Only species with sentient ability to destroy everything and overrun other types of life in the universe in an aggressive manor need limitation by universal law because from the general sentient beings curiosity fulfillment need of an explorer and respecter of the universe is come the Universal living beings right to happily exist naturally just so more diverse things are out in the universe for ever to be seen and experienced by all space farers because once there is nothing left to discover and nothing left to invent and the only driving factor left to us becomes need of resource to maintain and everything has been cataloged and learned we will become pretty bored if we have to look at the same thing everywhere. Travel and diverse leisure activities will inevitably become the focus of our existence. Can't wait.
Thanks Mr. Andersen 4 this brilliant class. I want more technical information about. 4 ex. in the secondary mirror (or other intermediary), how mutch must be the distortion of the surface? Other: It's possible to use the electrostrictives property of quartz about? (to build the secondary or some terciary mirror) So you needs not more than small silvered surfaces connected to computer, like a net I want your FB friendship, to ask more.
One question: why does it have to be so expensive? If one would mass-produce it, it could be in the range of amateur-astronomers worldwide. It would be a vast market-opportunity...
Yea mass produce 3 m miror with sensitive elektronic instruments. Even amator telescopes do not sell that much and those are mostly build with 200 to 300 mm miror. It cost 1 or 2k dolar if you are getting a good decent one now apply on that price 10k more just for hardware and you need to be really tecnical to use it. Now how many people will need that to massproduce.
@@cemoguz2786 obviously, I meant a miniature version, not one for a 3m telescope. ;-)
The same (counter)argument you are using has also been used in the past with computers as well. They used to be massive, spanning a room, and costing 500000 dollars. Back then, there was no vision of a possible "mass market" neither. In fact, Thomas Watson, president of IBM, notoriously said "I think there is a world market for maybe five computers."
Well... we all know how badly that claim aged, don't we? Nowadays, thanks to miniaturization and mass-production, we can buy a decent computer for 500 bucks, and they're small enough to put in your pocket. Yes, for a thousand times less money and a hundred times smaller, and that within a few decades.
My point was: one should go the same route with adaptive optics. Yes, if you make prototypes for 3-10m mirrors, it will be both massive and expensive. But just like with the computers of old, if you miniaturize and mass-produce it, it will be a huge success as well. Once it only costs 500 dollar and can be used with even a 25cm mirror, I bet almost all serious amateur-astronomers would buy one.
Very useful video and i am going to make lake that experiment!!
No mention about the width of the field which is being corrected by ao. Just a star?
Thanks for sharing
“CursED, life giving air!” I’m using it, ha!
What about the mirror. Is it a thick glass mirror or made out from a thin material
...And speaking of boiling rage, don't get me started on the SF shows that show twinkling stars through the starship windows.
maybe there is a heater in front of the window ;-)
I found this extremely interesting. My knowledge of optics is mostly limited to the material covered in the optician course, and even then there were parts of it that I memorized without really understanding. I think you've inspired to me make some videos on the optics of glasses -- which I will probably run by you to make sure that the math parts aren't screwy :)
"I would like to hear more about how the correction analysis itself takes place."
I'd like to know this, too. Are they comparing the current image to the deviations observed in the point light source? There is only a foot of atmosphere between the point light source and the detector, but there are miles of atmosphere between Jupiter and the detector, so I don't see how a direct comparison can be made.
Also, the wiki page doesn't really get down in the nitty-gritty details, which is what I'd like to see.
I look forward to the videos.
david21686 With our table top experiment we used a 'synthetic' atmosphere. That glass disc at 7:15 looks perfectly clear, but it's actually distorting the light from the laser into that wavy patern you see on the science camera at the end
Great video! But I have a question though. Why have a physical shape shifting mirror? Wouldn't be much easier and faster to have a program that grabs the reflected image, calculates the distortion and generate an image on the screen with a corrected image?
Well I think the science fiction software programs from CSI or other films where they can resharpen a blurry image to toal crispness are just that... plain science fiction. (well, ok, at least to a certain amount, because there are real applications indeed).
The problem is, that if the image is already taken, you cannot determine from where a photon came from any more. You have only a 2-D representation of a 3-D input. The third dimension is lost and can only be predicted to a certain amount. That's why the photons have to be guided to the goal before they are captured.
MrVankog Thanks for your reply. I see your point.
But It might be not that far fetched. There is a commercial camera called Lytro, that's capable of focusing the image after the shot is taken. I'm not sure how it works, but what it supposedly does (if I understood it correctly) is that it breaks the main image with an array of "microlenses" over an image capture sensor (not exactly a camera) and in the end the algorithm figures out where the light is coming from, and then it focus the image. This technology is available since 2009 and I guess it wouldn't be very complicated to adapt it to astronomical observations. And even if the processing takes some minutes, you usually don't need a "live stream" to observe stars.
So what it basically should do, is to record the 3-D input and then process it after the information is captured. The advantage would be the cost and also don't rely in mechanical piezoelectric mirrors, that I guess can be a problem for resolution. I have no idea if it would be doable, and I guess there are much smarter people than me thinking about it already.
But I have a gut feeling that it would be possible, maybe not with current technology but I wouldn't classify it as SciFy.
en.wikipedia.org/wiki/Lytro
Nix Dorf You are right. I heard of this too.
However, I think the main point with the solution in this video is to stay as compatible as possible to existing telescopes by just adjusting the mirror instead of the hole sensor and machinery. What you are talking about is a whole new approach for new telescope technology. Maybe we will see something like that in the near future.
MrVankog That seems pretty spot on about the direction of the photons being important. I've actually played with a Lytro it's quite a cool toy, but I don't know how they record the 3-D input. It could be as sloppy as taking multiple images with different focal points.
I have a feeling the Lytro is probably not the most efficient when it comes to capturing photons, thus making the image dimmer. Not a problem for a daytime shot of your friends at the beach, but astronomical objects often need all the light they can get. Adaptive optics can be better at catching every spare photon, especially with a guide star.
Again: I don't know how a Lytro works, but my suspicion is that it sacrifices brightness in trade for having the direction of the incoming light.
I think the most direct answer is because the computational load required to do this is actually quite large, and when you are trying to keep up with the rate at which the atmosphere is changing this is probably just too hard to do. Cool thinking though.
Wow, I would like to hear more about how the correction analysis itself takes place.
And It seems like it always analyzes the current image/frame and applies the found corrections (retrieved via magic) to the mirror, right?
So this means, because the atmosphere is constantly changing, the image cannot be perfect, because the correction measurements from the current frame _n_ are applied the the upcoming frame _n+1_ that possibly has already totally different atmospheric deviations.
It sounds like the main way the try to deal with the n+1 problem is by increasing the frame rate, which limits how sub-optimal the correction can be.
It is possible to create sensors that would give you enough physical information about the incoming light to do the correction digitally (I think they are called 4-D sensors), but I'm guessing the cost is still too high to build a telescope out of them.
*EDIT* Double post removed. No idea how that happened.
StubbornProgrammer That sounds about right.
MrVankog You have to remember that air is still fluid, it changes densities as warm air rises and cold air takes its place, this is a pattern that can be predicted and captured as information using this lens. This information goes through computer chips which use algorithms with many variables that can be adjusted to predict this flow and bring up a sharper image over time. Believe it or not, a computer does more than 1000 calculations a second already, it can easily adjust each lens and predict how the air will change as it is doing it. The constant feedback from the camera that shows the images in the grid allows it do adapt as conditions change in its prediction.The only downside which you've pointed out is that the first image will not be sharp, but as each image is taken the computer can adjust each actuator in the lens to make it sharp.
This is some very cool shit!
Since the computer must first see how the image is being distorted and *then* move the mirror, how does it compensate for that time lag?
+Diego C. I'm not an expert but here's my thoughts. I think the lag is kept under 1ms to minimize the effect. You might think that reacting to a 1ms future prediction of the wavefront distortion would improve things but it may be too difficult to accurately predict. I'm interested to see what an expert would say on this.
It doesn't. The correction isn't perfect, but you try to keep the update rate considerably faster than the atmospheric changes so that it doesn't matter too much. It's like when you drive a car. You see the car start to deviate from the center of your lane, so you adjust the steering wheel to put it back near the center. Your tracking always lags and is never perfect, but it is good enough to keep the car on the road.
@@IARRCSim Quantum computers might fix that in the future.
@@twistedyogert quantum computers are practically useless right now and progressing quite slowly. The sensors and conventional computers will likely get good enough to either reduce that lag to microseconds instead of 1ms or make a useful prediction before quantum computers become useful for adaptive optics. 1ms is long enough for a 1GHz CPU clock to run a million cycles and that could be a lot of calculation so I doubt computer processing speed is the main bottleneck anyway.
hello, can you please instruct me as to where i can get or to which companies sell such "phase screen wheels" as is presented here?
Dudy Karl Don't know any off the top of my head, but I imagine any optics company would carry something like it. Or at least they should be able to direct you to one that does have them.
Just love to see science at work. Curious to the computer and program used that can analyze the light and get the mirror to adjust as fast as the atmosphere changes. As said 1000 times per second would take some serious processing.Depending on the amount of light particles it is analyzing at any time. Oh does it do it's calculations per particle or per pixel?
In this set up I think it had to do the calculation for each lens in the grid that was held up to the light. (the waveform thingy ) So maybe a few thousand inputs were needed for the computer to do it's thing.
This is a big issue with modern AO systems and a lot of time and money goes into solving the huge computational loads when trying to keep up with the atmosphere. This problem inherently gets worse when you increase the number of actuators (and thus lenses in the wave front sensor), which we do to get an even better correction.
I imagine a system of recognition type software could be employed much like facial recognition but with obvious parameter changes to automate the adaptability.??
Cold this be done by software?
This is applied knowledge
Have we just simply looked over BCI solutions? Piezoelectricity arrays like the ones used for telescope correctional lenses may be a BCI solution because pressure or sound waves may also be present in neuron activity according to Thomas Heimburg from the Niels Bohr Institute at Copenhagen University and Andrew D. Jackson, who is an expert in theoretical physics. For now BCI electrodes scar over and it is not a lasting solution. So, is solving the problem of sustainable BCI as simple as looking at the problem differently with already existing equipment. Has anyone during brain surgery tried using piezoelectric stimulation on the brain during surgery? Keep in mind, pun, sound focused stimulation to mouse nerves to move their tales has already been done. Looks like it is worth the added 30 seconds in a brain surgery to explore this question, and see if sound is a feasible BCI alternative
Nice mustache
I'm pretty sure he just forgot Movember ended :)
Pee et zo?
so the atmosphere acts like water like when you're looking down at a fish it's all wobbly and distorted, does it also do that light refracting gimmick or is it too thin? i hope someone makes some damn high tech future sunglasses to fix that to make bow fishing easier cuz i wanna try, also wanna try using a harpoon or spear.
I always use the water/fish bowl example when talking about the atmosphere in demos! The light being refracted by a hot 'pocket' of air is different from a cold 'pocket' in the exact same sense that the light you see in air (above water) refracts differently from the light you see below the water. All materials have different indexes of refraction. Also I agree about the fishing thing, badass!