What’s Holding Back Your View of the Stars? Common Eye Deficiencies Explained

welcome back to this very special two-part episode on the physics of the human eyeball done in collaboration or rather inspiration courtesy of my friend Andrew huberman who speaks often about the eye and the effects of sunlight on the human eye supposed to go on this podcast at some point we'll see when that is and when I do I want to talk to him about the similarities between the human eye and a telescope and how understanding the limitations of each allows us to use both in a better more optimal fashion as Andrew likes to say we like to provide these at zero cost to consumer in today's video we'll talk about the deficiencies previously part one we'll have a link to it up above we discussed the magnificence of the human eye and how it does what it does and the similarities between the human eye and a telescope we're all born with two refracting telescopes as I said we talked in part one about how you can improve your telescopic vision and even what supplements you might be able to take to improve your night vision astronomical techniques including averted Vision using your peripheral vision understanding the limitations of the human eye allows you to use it in a much better fashion and that's what today is about a reminder you can get my free telescope buyer guide down below when you join my Monday magic mailing list at Brian king.com telescope so let's dive back in into the eyeball this time with an eye towards its deficiencies it's lacune my favorite word several different factors can degrade your ability to do astronomy using the human eye the most common is something like nearsightedness or farsightedness or a stigmatism these different Optical effects can give you different challenges when observing things through a telescope or even with a naked eye not using a telescope so we'll cover several different types of eye deficiencies now and how you can Rectify them some are easy some are impossible to rectify unfortunately let's start off with farsightedness otherwise known as hyperopia hyperopia or farsightedness is a condition that makes it difficult to focus on on nearby objects but distant objects including stars and planets they remain sharp it's easily corrected with contact lenses or glasses myopia or nearsightedness causes objects to blur but it can also give you an edge in observing fine details like craters on the moon you can use corrective lenses to assist with this and you can also use something called lasic which was pioneered by past guest Donna Strickland in her chirped pulse amplification technology of blasting lasers over very short time scales over ramping on frequency range as we discussed in this interview with Donna Strickland and she'll be featured in my second edition of interviews with nobal laurates coming in early 2025 just before Andrew huberman's protocols book comes out I got to beat him before he takes up all the science oxygen now for stargazers lasic can provide Clear uned Vision but some may experience side effects like Halos and glow on bright objects especially at night and I'm a poster child for that I got lasic in 1997 and I only got it in one eye my r eye or what I used to call my bionic eye and ever since then it's been suffering from many conditions like dry eye and I do see Halos around objects it doesn't really bother me that much and it is certainly better than having to wear glasses although I'm now in my 50s so I do need to get corrective lenses on occasion to read stuff off the teleprompter stop reading now I'm just kidding and lastly as I mentioned there are two other factors that can degrade the human ey's ability to capture staright a stigmatism which is causing stars to PE stretched and this is due to irregularly shaped corneas glasses can help with this as can lacing and lastly two other effects that do lead to degraded vision and sometimes can affect your night vision are floaters and color blindness they have less of an effect than you might think especially color blindness because reducing the ability to see the knight's colors is actually not necessary for enjoying almost any sight through a telescope unless you look through the giant mellin telescope which I'll show pictures of my visit to the construction site in 2019 the enormous alter of science I could see through a 6 M diameter telescope four times the collecting ER of the Hubble telescope I could actually see colors in astronomical objects with the naked eye alone but usually I would say always unless you have access to uh the giant mellan telescope or a similar telescope with enormous aperture you're never going to perceive colors with ordinary eyesight alone so color blindness doesn't really hurt you floaters on the other hand can affect you I have them in one of my eyes and they're typically most pernicious when you're looking at bright objects which is not really going to be the case unless you look at the moon or the sun through your remaining good eye but remember never look at the Sun that will cause permanent blindness uh through a telescope unless you have a solar filter or similar device to prevent the overwhelming brightness of the sun's intense light so almost all these are managed with proper Eye Care I sometimes use eye drops #t notsponsored but don't let them stop you from exploring the wonders of the night sky another deficiency of the human eye of course is that it can't zoom you can't change the magnification really very easily if at all but as you can with a telescope by swapping in different eye pieces can't change the aperture on a telescope either but you can change the eye pieces and that causes the light to appear more magnified as it comes into your eye but the total amount of light won't be magnified you won't see it brighter because you have a higher magnification you might see it more intense and and a higher density of light perhaps but you can also get different filters to observe different objects and actually cut down on the light now that we've covered the different problems with the human eye well cover some of the nine idealities or systematic effects present in actual telescopes refracting and reflecting now as promised in our cosmological telescopes we often use lenses as well these are not used in professional grade instruments like the cek or web or even uh large groundbased telescopes but they are used quite frequently in microwave telescopes in fact this is one of the original lenses from the bicep experiment which I built became bicep 2 that of course led to the story of bicep 2 and the reason for my first book being called called losing the Nobel Prize I refer you to get that book on my website Brian king.com books the inability of bicep 2 to win the Nobel Prize was had nothing to do with the fact that it was a refracting telescope in fact if it wasn't a refracting telescope it probably would have never been built and that's because the science that we needed to do only required relatively low angular resolution about a half a degree or even less to resolve these giant B mode signatures that would be present if the universe experienced a period of hyperexpansion called inflation that's what we're trying to see the aftershocks of ation are gravitational waves primordial gravitational waves not from black hole spiraling together in the relatively mature Universe of just a few billion light years distant from Earth those types of gravitational waves have been discovered since 2015 by my friend Barry barish Ray Weiss and Kip Thorne have interviews with all those on this channel and of course Barry wrote the forward to my second book think like a Nobel Prize and Kip Thorn is featured in my upcoming book in 2025 called Focus like a Nobel Prize winner Focus get it like a telescope so let's talk about these deficiencies and what goes wrong in different types of telescopes so both refractors and reflectors suffer from non idealities there's no such thing as a perfect telescope they all have flaws in them and those flaws have to be introduced we have to remove the effects that are caused by the system those are called systematic effects no amount of observation no amount of Statistics can get rid of those effects unlike statistical errors or noise which can be improved by taking more and more data over longer period periods of time of course when you take statistical considerations into account you don't actually improve linearly in time in other words if you take twice as much data you don't improve or shrink your statistical error Bars by a factor of two you actually only shrink them by a factor of square < tk2 so it takes a long time to get the data much much lower in statistical significance but if you have a systematic error there's no amount of observational data quantity that can overcome the deficiencies caused by an error in your system for example if I was using this which is nearly perfect for microwave astronomy obviously if I was trying to look through it to see invisible astronomy you wouldn't see anything and that's because these absorb systematically all visible light and you can't see through it but microwaves go right through it similarly if I were to use glass like this lens on this optical telescope as a microwave Optical element it would absorb a tremendous amount of microwave energy so these are different trade-offs that we do those are examples of chromatic effects effects that depend on the color or wavelength of light now for refractors it's a particular problem because refractors have a problem called chromatic apparation where different wavelengths of light focus at different points causing the fringing of colors to occur this affects the clarity sharpness resolution and it's most noticeable in lowquality glass to get a very large lens an optical L this lens cost maybe a few dollars to make at a machine shop at Caltech where I was a postto but a lens made of high quality glass that's this size might cost 50 or even $100,000 it's a large lens 8 in diameter you see the holes that's for mounting it and and this is actually made of highdensity polyethylene actually it's ultra high molecular weight polyethylene incredibly convoluted acronym but it's actually one of the best materials it's actually very low cost and you can actually machine it to make the byy convex shape that you see here now a reflecting telescope suffers from no chromatic aberration because the mirror surface reflects all wavelengths pretty much in the optical more or less perfectly doesn't do it for highend energy X-rays and gamma rays that's for another video now both reflecting and refracting telescopes suffer from spherical aberration and actually your eye can suffer from this too and that's the fact that the spherical mirrors which are easier to make than a parabolic mirror which is actually technically required to focus light into a point a spherical mirror doesn't do that perfectly so you get what's called spherical aberration that occurs with the lens shape as well the lens is not a perfect sphere or conic perfect conic section and that results in a blurred image when the light focuses different physical geometric points that's a big problem reflecting telescopes suffer from another effect that refractors typically don't and that's called coma it's not the medical condition of being essentially brain dead but actually it's the fact that stars in a refracting telescope often appear stretch and they appear like a comet and that's what the word coma means actually coma means hair uh but if you kind of think about a woman's hair as sort of the silhouette appears just like a comet and you see these effects in Starlight as well and you want Starlight in either reflecting telescope or refracting to be a pinpoint Ultra sharp these stars are so far away we can't actually see the expansive discs of say the sun they're way too far away and so they should focus basically to what we call a point source in your retina or in a CCD camera now both refractors and reflectors suffer from thermal effects both expansion and contraction over the night or over even a short period of time the lens or mirror shape and position can be distorted due to thermal expansion that affects the optical performance especially in large professional telescopes our telescopes our Optics are at 3 Kelvin or at 40 Kelvin and even colder than that so we keep them exquisitly stable and this is an area where your eye does better than a mechanical or even a telescope because your eye is inside your head it's basically kept at the same temperature all the time so it's very hard for your eyeball to change temperatures I've been to the South Pole many times and even when I'm there at -40° C which is also 40 fah the eyeball never freezes in place it stays the same warm cozy temperature another Optical effect is called vignetting this occurs when some parts of the telescope's optical path block some of the incoming light causing a darkening of the image at the edges it's very common with reflecting telescopes because often times the reflecting telescope has another mirror in the center and that's part of the nutonian design called a secondary we don't have that in our Simon's Observatory large aperture which is our reflecting telescope but uh many telescopes including kek telescope and upcoming telescopes like the giant mellan telescope have another mirror and and that other mirror I'll show the diagram on the screen of a reflecting telescope blocks some of the light that comes in and you can also have defraction where the light scatters off the secondary mirror the structure that supports it there's also another structure called the spider which holds the secondary mirror in place for a Newtonian telescope and you can often see the effects the defraction spikes from those effects in images including the Hubble Space Telescope suffers from this the James Webb Telescope has an off axis secondary so this the light doesn't actually come in through a path that would cause it to reflect or defract around the secondary so its images are different but it has the fact that unlike the Hubble Space Telescope the James web Space Telescope is made of panels and those panels called scattering which is an effect that afflicts both refracting and reflecting telescopes and in fact the web telescope is of course assembled like origami in space at the lrange point L2 it's about a million miles from the earth and they had to do that to fit it inside of the rocket fairing when it was launched uh from South America on Christmas 2021 and that causes it to be as large as it is but it's made up of all these subpanels well the subpanels have interfaces where these hexagonal shaped subm mirrors about a meter across where they come together and that causes scattering and you can actually see the spikes from this effect the scattering and defraction and James web Space Telescope when you look at a point source like a star shows six uh spikes surrounding each star the Hubble Space Telescope shows four because it has a secondary support that has four a four-fold symmetry and also the pixels are are also four-fold in symmetry as well now both refracting and reflecting telescopes require regular colation which is the alignment of mirrors and refractors are much more stable and compact than reflecting telescopes but both telescopes suffer from misalignment issues so both the human eye and telescopes gather light differently to form images the cornea and the lens in the eye work similarly to a telescope's objective lens although it's just one single uh lens in the human eye and most telescopes have two one called the I piece at the where you put your eye and one called The Objective in the direction of the object our eyes are very similar to telescopes but they also have these other effects human Vision has has different effects that make it less than ideal and in fact throughout history these effects have been made clear both from early astronomical images sketched on Cave walls in the Paleolithic error to the beautiful artwork shown here by Vincent van so I want to show here Vincent Van Go's starry night and connected to some of its very interesting astronomical depictions that are shown there it's more than just a pretty picture the actual atmospheric physics called kagor physics is captured within van Go's beautiful illustration so some say that Vincent Van go may have suffered from xanthopsia a visual condition that causes a yellow tint in one's perception due to digitales toxicity now digitales was a medicine used to treat epilepsy some historians say he may have been taking it and have this pigment issue causing the vibrant yellow as depicted there Additionally the swirling pattern have been compared to turbulence and some say that he actually suffered from any particular eye disease he may have suffered from nearsightedness farsightedness that was uncorrected and that may have led to the depiction that's shown in this beautiful image now as bad as his eye disease might have been it's nothing compared to what would later happen to his ears I'm not going to get into that on this channel you can look that up for yourself so I hope you enjoyed this deep dive into the eye and telescopes including some thoughts that I hope to share with Andrew hin when go on Hebrew man Lab podcast or when he comes on mine we have a lot in common and a lot of hopefully very interesting things to talk about let me know in the comments if you have any questions or comments for Andrew he's done a tremendous amount for discussing how our son which is a star my domain of course affects our mental well-being and I'm hoping that we'll get to talk about those topics as well so leave a comment down below what would you like me to talk to Andrew hberman about