This episode of astronomy cast is brought to you bye swing burn astronomy online the world longest running online astronomy degree program this ed astronomy dot s w i n died at u dot eighty for more information. Drunk junk episode one hundred ninety room on me june twenty eighth two thousand ten. You don't see and making was trying to be caps or backspace street too because moves real people just in only what we know what how we know what we know. My name is fraser ok number publisher university and with me doctor pamela t a professor itself and a little university depths bill pamela you doing i'm doing well how are you doing fraser doing very well so um i think we're gonna. Give into summer give you the summer this is the last episode all of the summer so to date on this june twenty eight. We're gonna take too long in august off. And by going to i mean we order did and now we're just gonna make it official so you what the soaps from junior twenty eight too old really september and then we're gonna be doing dragging corn. I'm really trying to log shoulder we will be a live show there and then um regular schedule continue after that when. When you were summer travel schedule uses up. And we're going to be bring you back the question shows and we're going to work very very hard to get back to our old uh we launch on mondays we lan thursday it's and yeah we're gonna try if the goal it'll between and swinging. And to drink on september labor day weekend uh in atlanta both of us are gonna be there we're gonna be doing a lot version of strongly cast and we're going to be on a bunch of other panels. We will be we're gonna have t. shirts c d's so eight if you want to come and hang in need us and. Good for beer uhhuh will be there then that'll be great. And uh where we're hoping that all of you will come and get astronomy cast tee shirts place they're pretty they're pretty cool i like them actually. Natalie k's to their c d's intestinal go be did our t. shirts and we love all of our wonderful creative listeners like those too. And then old soon thursday night on a second alright yeah these are party. Yes there there's an ad maria walters one of the skeptics is. Arranging and a moon over cancer start party to raise money to help to see cancer and. The name of the blue collar scientist jeff not cast and i fraser and i will be there and i'll be giving a talk on for this and science and we hope that the rest of you will come and. Helpless raise money for the american cancer society and there's some information on yeah on the line joe skeptics. Uh website old ones are going to so on their side. And i'm sure will blossom looks miserable too. Okay horrible too i'm sure there so starters measure the bright is who stars as magnitude but this bright is depends on the distance to the store as well as the total amount of energy to pumping you know into space. Different vantage points your appearances can be deceiving. So what's what's going to court was given terminal job away so what's we don't see. It is a measure of how much flux of so times how many food tons per square meter measured in units of energy are coming off of an object and then magnitude. Ninety two is a way of taking that linear set of numbers and transforming get in into what your eyes see so if you double the number of women off today the number for though time's double. If you double the number in magnitude systems it's some crazy like with me scaling craziness. Right to the point being that there's two kinds of makes right there's absolute magnitude and apparently you'd yes and and both of those have this crazy non linear way of looking at the numbers. But the a parent magnitude system is how bright something actually looks in the sky you look up you see it you go oh dot ninety two three. But absolutely magnitude is kind of like the number you read on a light bulb box. If you're a mile away from white bald it's not that right if you are right next to light bulb it's really bright but in both cases it's going to be the same living off the d the same absolutely magnitude that it says in the box a hundred watts or whatever why does this matter. Well if you're trying to figure out how to compare to objects. If i'm looking in the sky at a really close nearby average monday and start. It might appear to be the same brightens as and she'd norman giant universe the valerie not really they don't do that giant hundred solar mass star that on the other side the galaxy from i. Right some of the close the stars are invisible. Right well some of the brightest stores are you know as distant are the most recent and yet in this guy they appear the same starts tell them apart yeah yeah and that's the parent right now right. So if i wanna make a meaningful comparisons these two objects that's where when honesty comes and that's where absolutely magnitude comes in. And that's what ninety two is the number you get it both objects were ten par sex ed about thirty light years away from you. Yeah i've seen the matrix system before i mean. There's a a new a number of sushi did with the brightest of all of the objects you know the moon has this magnitude this on is that magnitude and to do miss stores visible would be unneeded i have such and such many to critical weird is this just. To give away so we're just this numerics in compass eastern well it was first documented by told me and i would probably came originally from home park is and the the system starts with just the rather simple. Let's take the brightest stars in the sky call the magnitude one take the faintest stars in the sky call the magnitude sex. And build in between where one to two is roughly a doubling ah two to three is roughly doubling according to your i balk. Now our isell's our money our systems this is the problem what your eyes seizes twice as bright your your little detector that you have for your camera i won't. But it was a system to start with and so it got work with for a long time and then it was realized well you know maybe there's a bunch of stuff out there that's even brighter. Sit in the system got reworked with the star van gogh um which is one of the brightest northern hemisphere stars but not the brightest just one of the brightest. It got redone as magnitude zero and we based the entire system on magnitude zero in a given detector to given time through given filter set. And now we recognize it vegas actually magnitude zero point zero three couldn't. So the system is based on they go zero thing this thing you're human i can see under normal dark skies unless you're super human person steve i'm here i can see center than that that's magnitude sex and most big cities you can see magnitude for. Soon this in the i guess in the olden days uh this'll hold on visually and. That must have been really open to interpretation i mean everybody's always a little bit different trying to say well you know the stores brighter investors doom or i think it's a for i think it's a fi- five point too it must have been a really. You know the exact science and then now we have is more instruments right where we we're. Where she should you can tell you exactly how many. Full tones are falling on it and and give you any definition all the crazy thing is helen and exact it license. The human body is of very it accurate measure is long as you have things that you know they're bright. So you start with vaguely you label it zero and then you move your way across the sky labelling things that are non standard now if you can get a bunch of people to agree on a handful of stars scattered across the sky and they're bright and it says. It's possible to work your way down from that and what organizations like the american association variable start servers have found. Is human beings if they're looking out objects nearby on this guy and they now this one's magnitude twelve point four and this one you can block that would be binoculars they know this one is ninety two three point four. This one over here's three point nine this when over here is three point two. What's this one in the middle it's in three range as well they can in the case is the best of servers and get it accurate down to an extra decimal point it's. Three point four six. And there's an error and that but. They're tracking c c d measurements so if you take the best observers the average there measurements together and then compare it too i c c d you can see all the same nuances in like her. And so that as you say be the main skill easy is it doubling is that right doubling of light so to go from. From see six two five fifteen twenty two as much like coming from the store well and this is where what you perceive differs from reality so it it's really a lot great make system so. The reality is that between. Uh ninety two one star in a magnitude six star. There's a factor of a hundred times and the actual light coming off of it. And it's running i've been added all of the object into the scale right so bad things can be awhile brighter then zero missiles were just kind of weird um and things can be a lot dinner then sixth. Right right so it turns out that. I really bright stars like serious stand up with negative magnitude to and it's it's always curious to say. Welfare says the brightest star and as the magnitude of negative one point four only in astronomy with that happens this time the it's the magnitude mine is twenty six point seven. Full moon again minus twelve point seven we like point seven to parent like. But then stand objects the hubble space telescope it can and it's d this magnitude according to some of the websites i've looked at get down to ninety two thirty so the idea that these really high numbers. Are really faint objects is a little bit brain breaking when you're first learning how to do do the magnitude system so if we could start all over again somebody was it like this on ah zero and then. Uhhuh up from there about. I i don't know the best way to set it in the so the problem is that we're used to hire numbers mean bigger so does that mean you start off by setting the sign it a million and work your way back where it's. Yeah how how do we do that and so they we get the ordering correct and we just don't know that it it's a confused system but trying to come up with a replacement system for the human i is something. We don't quite know how to do and this is where radio trying m'ers where you're i never saw in radio so they can take certain liberties without confusing people they simply count the times. And they count that they talk about how many jammed skis how much energy they got in a perfectly lenny your system. What did you that on the high end of the skill to was with. Galleries and you know. They're getting they're getting like shocked by bullets right really field as opposed to just you know how much light right so there you start talking about how many elect trying to open up many mecca like tom bolts. Yeah um you have coming from an object so depending on what part of the electric nine expect for your and we like to switch are you in the top. But when you fall into that optical ranger to him and i can see not only do we switch upper units but we change the scale entirely it's it's right in there a few problems with this believe it onto the is the total amount of energy. Being fired out from this body from the start how much is a meeting in in always wings right. While the magnitude is just a measurement office individual. And and i need to create we use different filter so originated with the human i which we now call the v so for the visual soldier we've figured out how to take glass and. Change the glasses properties so that the light the passes through the glass is similar characteristics to the amount of light and d colors of light that your i perceive so. But then we also like to look at objects using read filters that highlight things like myra variables and distant galaxy as we like to look at things with blue filters that highlight star formation. All these different filters you get a different minded who do you get a different amount of light coming through the filter depending on the color of the object. And then objects temperature decides what color it is so the very complicated system so it they go they pegged it is zero and several different colors. But. Then we talk about women off today that's all the colors and in magnitude we do you use this word bowl not trick to refer to the ball the metric ninety two days the magnitude the object would have if you can measure it's light and every single wavelength. Right okay superbowl metric manger that's a way to get a sense of. Of what this real quick if you could see was your eye balls and every wavelengths. So that kind of solve that problem. Well delivery from the we have with me she was that distance who's everything yeah but you would restoring this guy and we see it to a certain level bright news. But that doesn't tell you at all how how bright it truly is how rude how does remembers figure this out. Well we into lots of calculations luckily there's certain stars that are close enough that we can tell just by the earth's motion. From june's of december as we go from one side of the sons or but to the other. We can tell how far away they are but how they appear to move against distant background galaxy this is the same way you my measures d distance your television set by blocking the television set out first with your stumble out looking at it with your left icon. And then closing your left i know but you're right i ain't seen how much you go some move that will give you brother is not the distance your television to the distance your thumb because. The television set a distant non moving object and. You can see the angle your thumb moves you can measure with a ruler the separation between your to people and if you like chicken on the tree you can then calculate how far away your time was when you made these measurements. Everybody's you just right now we don't care if you're the boss where are you artistic your or remote who just almost. And then just. Switch unable against and look at o. your phone moves back and forth. Against. The background and you can calculate just just on that way. And so we use that principal this tires and distant galaxy is and instead of left bald eyeball we do earth or been on one side of this on the earth or been on the other side the sun. And once they know the distance to an object and once we know how bright it appears. Well things to physics we know how the light changes with distance it's actually it's a as a distance goes out there because it's the squared the distance so if something. Goes from one foot away from me to three feet away from me i'll actually get one night the amount of light from that object. Using that physics of calculating how the amount of lately receive changes with changing distance. Were able to build up the picture of okay that object that that none distance hasn't this absolutely magnitude this actual animosity this other type of object. It's completely different but now i know this other type of object that can also measure it's distance i can also measure it's bright and if i can calculated swimming off so we build up this picture of what all these different objects well click. And when we're lucky we look at the same type of object. Thirty times and it always exactly the same. Unfortunately that doesn't happen very much that pretty much happens for standard candle objects things like r larry stars steffi variable stars type one at super now see. Which luckily haven't gone off close enough that we can measure them being paralyzed but we've been able to tell the break those using steffi it's an r larry. So we start to build a picture one object at a time getting more and more distant in the universe of standard candles and then we start. Going ok this object i don't understand it's orbiting this object i do understand so now i know it's brightens and living off the things to calculations as well. But without. Without knowing if you can only use the break just for the magnitude. To determine due to distance you after you have to get it the distance some other way gas and then once you have that and you know which it's. Current brain is you can then calculate how bright you really is she flew no city and it's absolutely to to yeah getting it distances is one of the most important and most difficult things we doing astronomy. It's it's so hard to measure distances we actually did i believe an entire shuttle dedicated to distances and if i hope loose and they did this whole record that next no no no it's it's one of her early ones measuring just since the universe. And it's like this latter right with up close. You've got one message and then you've got your and your next method of measuring distance any kind of overlap and that's how you know use one to validate the other one and you keep going up this letter all the way you know to being able to measure to the very edge of universe. And it's amazing how we build the pieces together and it's only because we have this wonderful latter that we can start to say hey i know exactly help right you are when we're looking at our favorite galaxy sometime i was distant super clusters i've got like see. So we've been what is the most of water what is one of the most voluminous objects that we know well that that's one very simple answer if you want something that lasts more than a few seconds and that's quite sars. An individual queries are this is the heart of a galaxy that may not be that different from around milky way galaxy. But all galaxy as as far as we now have super massive black holes in their centers black holes that can be as much as a one followed by eight zero is um times bigger than our son so that's. Uh ten million hundred million one billion yeah does it can be a hundred million yeah two billion times more mouse is it's on yeah so. We we have reached the point where we have to add some of these areas to things that we start talking scientific no picnic patients so the these black holes or you tend to the eight times bigger than our sign in many cases. Now when an object falls into one of these giant black holes it gets shredded to bits and not only does it get shredded that statistics salary did violently as it gets shredded to that. And a whole lot of stuff is falling in at once. As it tries to accelerate in there's this whole process involving angular momentum just mathematically complicated but the core piece of information as it has to don't energy and it dumps a lot of this energies light. And so one of these qua sars one of these angry feeding black holes in the center of a galaxy. They can be by themselves a hundred times brighter than i milky way not brighter than our son aren't higher galaxy. So that that is she's to say nothing else at massively bright object and yet there's so incredibly far away that you need to of of us we still have to to see them. No no wait a little while holding neural you knew looking good telescope yeah you know even though they are the most most object to the university. You can't see with your eyes. There there is one exception and i personally when i look through tell skips mine is a kind of bad i'm one of those people that in dark skies conceive like fifth magnitude on a good day but there's one place aren't that is. In the magnitude twelve range that you can go out and you can actually see with your own nice. Initials in a backyard telescope you can't you you do need a telescope somewhere so this race but you know if you would your own i've like just be unneeded no no you don't you need a telescope and and this is three c two seventy three. It's one of the nearest it's one of the brighter in terms of objects in the sky up parent right now we don't know absolute right now but these are really fascinating objects so those for. Think the last more than a minute or two they're pretty impressive and war and the most moving his object you know guilty. And our galaxy it's probably gonna be one of the new born starts they actually just recently found a star that is two hundred and sixty say sync solar masses and size. Which is impossible well if that's what we thought but they don't have when i first start forming it hasn't yet reached the point that it just shut enough now. So right ah she's with soul young but it hasn't. Gone down two weeks possible yes right about the mouse just started now it's in the process of shedding all that now. Right so we that that's for robert believe the the brightest thing out there and i have to man i'm currently in the process of counting zeros on my screen. So we're looking at stars hundred times as nice as of as the sign are ten million times it's bright nice so i. These they they these are break. And leninist and women this is what actually matters in the sky. Right oh it was like either created an easy in that can't yeah so start you can see if you're in the southern hemisphere. With the unneeded i and it is house the galaxy away and yet um you know us or you can see it's gonna music. And and it's worth the tallest gothic look because there's an amazing nebula around and this is where what fraser and i were just saying about an hour plus comes into play because it's shutting its in mass because. Well it it's a crazy young star doing crazy young start things like shutting math and violent outbursts that we don't fully understand and not exploding and not to floating yet. Which it sure does it well but yep maybe not in our life type i want it to you i wanted to know. So i think uh been interviews and house right is something that's very gym and close i mean how four down. Are these things just deductible you say maybe two. Thirty for whole uh yeah what is that that would be a very distant galaxy that would be and distance small star. Some of the brown divorced it seemed to be reasonable distances can get that saint planets orbiting other stores well that depends on what color you are looking in yeah pictures able to make these planets out. So they're it's it's the heat it up by their son played if they're too close to their sign and they start to become reasonably visible. But would that be. Pavel just getting a couple of things one's from from an object that's it pretty much it yeah it's really amazing. How few four times that you're dealing with and one of the things that amazes me especially if you start to get to the higher energy so. Is a good detection might be sick slow time. But you know so tired and carries a huge amount of energy in it for of so time. Right so a high energy it's every third time gets counts and that's pretty amazing. Printer like use horrible. Detected one full during the cold that the full tones most distant galaxy a record you not somebody wonderful which ones are coming from well it's of the problem with it says you you run into noise and the universe is filled with these annoying things called cosmic rays as well. So you only see at high energy farrakhan or a visual energy votes on or a foot on it any color for that matter you. You can't say it's from a distant galaxy or it's from some radioactive decay that happened on the planet earth and went through the bottom i for telescope right on my television right exactly probably not get a television the shooting galleries at me but. Oh ok what is it covers um are are. Are depth into the break this or dissension brain is so that's great so as you mention beginning of a show this is gonna be the last episode for the summer so if you are getting this you're running would put a stop review shows no is just summer. Uh we back in september and we are hoping to get back to our normal one yes twice a week schedule and i. Fully recover from my travel and everything else but has blade. And we don't see which i can go so field there alright thanks no thanks to you later anything but astronomy care but we've we've both booster me through because journalism transcripts for every episode or available on our website truck about astronomy care though any comments courses were feedback ten folders or make a phone call we were you ever your mail so sure of a nonprofit educational resource provided by first advance our family there were supported through the confirmation what's right with you if you enjoy term care for one of his information it'll favorite band with transcript difficult to building went on the website. Although they sort of offer you a factor you can support sure for free to write a review for reform of your friends. Every little bit helps quick support here or what instructions drive it was true on your part of the software i'm sorry sir dot com. What part goes got a criminal worth a printer and the prices you because brought aboard trevor thorough sure was that it is programs astronomy test is pretty well but oh universally over at all with generous support from the university of it wow uhhuh odd i
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