Horizon (1964) s17e03 Episode Script
Beyond the Milky Way
To find our place in the heaven, we must journey in time, as well as space Here, new suns are forming out of clouds of hydrogen But we see it as it happened thousands years ago It is taken that long for its light to reach us A star cluster - the long ago brilliance of a hunder thousand sun We've come to understand that these and our own solitary sun are neighbors companions in a whirling mass of 100 billion stars The Milky Way - Our Galaxy Now, we are beginning to understand what lies beyond The light of this galaxy, the closest to ú, began its journey 2 million years ago Humankind had only just begun its first-up right footstep in the [apricorn.]
Earth Passed this galaxy in Andromeda are as many more as there are stars in our own Milky Way Dozens of galaxies for every person now alive and each is as distinctive as an individual face This one, the Whirlpool inspired our beginning understanding Its curious shape was discovered here in Centre Ireland, by William Parksons, the 3rd Earl of Rosse This is his descendant - the present day Seventh Earl of Rosse looking over the remains of what had been known as The Laviathan ParksonsTown These high walls supported the wooden cylinder that, for 70 years, held the biggest telescope on Earth You can walk inside it with a raised umbrella In fact, at the opening celebration in 1945 Its huge size was properly demonstrated in just this way The tube was movable as this scaled model shows It could be winched up vertically and, within limits, to the side But just like this smaller version, it all had to be done by hand Its main mirror was 6 feet across - 72 inches It was made of metal, cast [on the side.]
and then carefully ground and polished With time, it began to turnish Lord Rosse's hope was that with this monster telescope he would solve the puzzle posed by certain tangent fuzzy objects called 'nebulae' The Whirlpool was one, what were they? After 2 years of delay because of the potato fermine and despite the often cloudy Irish sky Lord Rosse observed and sketched this particular spiral structure again and again Its eye probably across the sky as the Earth turns on its axis 3 workmen moving the huge tube between its supporting walls Pioneer photographer such as Lady Rosse took pictures of the telescope and its visitors But they didn't yet think to try photographing the heaven In his sketches, we all distinguish between certain of nebulea and the spiral He posed question about the structure and their place in nature that could not then be resolved How large were they? How far away? Could they be island universes as some philosophers had speculated At the Harvard Smithsonian Centre for astrophysics historian of astronomy, Professor Owen Gingerich This thin wheel is a scaled model of our Milky Way Spiral a thin disk of stars, a giant system of more than 100 billion stars like the sun and smaller and with a dazzling [spotting.]
of much brighter stars that make up the spiral arms of the Milky Way It's about a 100 thousand-lightyears across and the sun is an average star in here Of course, Lord Rosse [hasn't the foggiest.]
idea of the [great extent.]
of the Milky Way and he didn't know how the spirals and the other nebulea fit in He was a natural historian classifying the nebulea wondering what they were made of whether they evolve Quite surprisingly, some of the answers to these questions came from instruments quite a bit smaller than his At the same time that Lord Rosse was finding the first spiral with the Liviathan Parksonstown this telescope was being erected at Harvard This and its twin at Saint Petersburg, in Russia were the largest refractors in the world Sitting in this chair, the astronomer George Bond made the observation for the finest drawing of the nebula, the Orion nebula, ever made But also here began that change of event that made drawing the nebulea obsolete Because here in 1850 was taken the first photograph of a star And before that decade was out, they had made wet plate of the Moon and of the planets But not until the 1880s when dry plate became available did astronomers take up photography with such enthusiasm With that new tool, with the permanent record astronomers found that they just couldn't detect directly any large scale evolution of the nebulea But whether the spirals were great congregated stars or something else That answer came from another [quarter.]
from spectroscopy when starlight is passed through a prism to form a spectrum among those leading pioneers was a mid-Victorian amateur [independant mean.]
William Huggins who set up a telescope on the second floor of his home near London With the spectrogram attached to his telescope Huggins found that the spectra of the [more.]
gaseous nebulea like the Orion nebula [consistent to.]
the bright light characteristic of tenuous gas But the spirals were much fainter and harder to photograph and not until the end of the century could Huggins showed that they had different spectra much brighter those in the sun and stars A star's spectrum has dark light where its light has been absorbed by cooler gases at the star's surface Huggins believed that the spirals were made up of stars but to answer that decisivey required more light-gathering power George Ellery's huge ambition was to chart the evolution of the universe to be, or possibly to find the [dark.]
one of the cosmos with a little help from his friends like Andrew Carnegie he had a [cyclo.]
near Los Angeles At the end of a winding trail on Mount Winston, the observatory dome was built to the height of 5000 feet with the 16 inch mirror made of glass the telescope was a little smaller than Lord Rosse's but it was far more versatile and it's still in use today New electric model was used to move the instrument In 1909, when it came into use, it was still unknown what the spiral nebulea were the telescope's mirror at the bottom gathers up the light and focuses it back toward the top from there it is reflected back down again to an angled mirror here The objective [.]
was sighted and a photographic plate was inserted to capture the image the object was then [pract.]
by choosing a star off to one side and keeping it [light.]
on target for the rest of the night, or even for the rest of the week Hale had already collected the money for an even a larger instrument and had chosen a sight for it nearby A second dome was built to house 100-inch mirror it would have twice the collecting power of Lord Rosse's telescope And would be the first to surpass its inside This is the instrument that should finally review what the spiral nebulea were [Early.]
little was actually known yet As the 100-inch came into use by the end of the first world war the spirals had become the subject of acrimoniest debate among astronomers the most basic questions had no agreed answers were they bright objects far away? or faint objects close by? Estimates of the distance of objects in the sky depend on a very complex chain of reasoning of which one vital [link.]
was found here in this building of the Harvard Observatory Here at the turn of the century, a woman named Henrietta Leavitt made a fundamental discovery by scanning numerous photographic plate for variable stars In Hen' Levitt's day, these plate stacks were considerably small than the other day but then as now, they housed a treasury of stellar images from both the Northern and Southern sky The plates had found choronogically and in this section are those taken in 1904 and 1905 which Henrietta Levitt used for her searches for variable stars this's a plate of the large Magellanic cloud one that was used by Ms.
Levitt in the early 1900s From this peppering of literally thousands of stars she found a few that systematically [rhythmically.]
varied in brightness, the Cepheids And then she made her key discovery that the brighter the star was, the longer it took to them to pulsate Just about this time, a young Missourian named Harlow Shapley out at Mt.
Wilson observatory was studying globular star cluster and the structure of the Milky Way the tightly packed congregration of hundreds of thousands of stars here they're marked with the circle and he found that they tended to be concentrated in a very small section, 1/3 of all known globular clusters in just 5% of the sky He wanted to find out how far away they were and for this, he made the assumption that Cepheid variable stars pulsating with the given period, say, 10 days were the same wherever they were found throughout the entire universe so he calibrated their absolute brightnesses and found how far away they were Now, at the time Shapley was starting his study of the globular star clusters astromoners believed that the Milky Way was a rather small sun-centered system but when Shapley found out that the globular clusters are the [middle action.]
were tens of thousands of lightyear away he decided that the Milky Way must be an enormous disk perhaps a hundred thousands lightyear across This was so enormously bigger, staggeringly larger than anybody had imagined that Shapley thought that this was all there were, the globular clusters, the stars, the spirals, everything but his critics were not so sure they thought that Shapley had radically overestimated the size of the Milky Way and many of them thought the spirals were actually independent island universes very far away And this all culminated in a very sharp debate before the National Academy of Sciences in April, 1920 Now, today we know Shapley was quite right about the size of the Milky Way but completely wrong about the distance to the spiral but in 1920, it was going to take some new and fresh observation to settle that matter At Mt.
Wilston, Edwin Hubble, a young astronomer hired by Hale, already suspected what was needed By [trailing.]
the 100-inch telescope on the biggest spiral nebulea he should be able to distinguish individual stars With these stars, he can estimate distance he [perceived.]
it meticulously step by step when one glorious piece of luck intervened he had been searching the Andromeda spiral for novae stars that brighten suddenly, then die away one of them brightened again, it was a variable, not a nova it had varied in the same way that Cepheid variables did he could assumes that it was one, too It did Hubble now knew its basic brightness so he could measure its distance reliably It lay far beyond our own Milky Way [And he.]
established that other nebulea do exist and that they lie outside our own Hubble classified their types Many are elliptical in shape, some round, some more flat some are vast, others relatively small there are the spirals, a fuzzy [.]
spreading range and we see each kind at all different angle Hubble wondered whether these represented different stages along some lines of development A 3rd class has what looks like a bar across the hub they're barred spirals many others [just not fit.]
they're undefined shape, Hubble called them the irregulars some are so unusual that today they're called peculiar galaxies Hubble continued [.]
to find out how far away galaxies are he also studied their spectra the spectral line of the galaxies are shifted, generally toward the red like the falling sound of a passing train the pitch of light, the distance between its waves spreads out the faster its source moves away to attain and measure these red shifts, Hubble needed help Milton L.
Humason came to Mt.
Wilson as a mule driver he brought up materials to build the telescope, then learned to use it one of Humason's graduate students in 1925 was Nick Male The exposure was very long, nearly a week sometimes and so the occasion of taking the plate out [in the vaulting.]
was a real traumatic offer and he invited me to come in one very very morning he cracked the door, he said he was gonna [vault.]
this plate without, would I like to be with him [He.]
carefully preserved the actual plate they took He turned on a red light and grabbed the microscope and held it up to enlighten a glass box and he looked at it, he said "My God, [there.]
we got a whopper" The whopper was the spectrum of the galaxy Hubble had estimated was very distant He'd asked Humason to check its red shift So Humason called up Hubble [after.]
dinner and asked [him.]
to pick up an [expulsion.]
so I heard the conversation right from the beginning And they said: "[.]
called the [Mr.
Hubble.]
" And Humason said:"Mr.
Hubble, you are right again.
You had it right [on the note.]
" we have twice [as large.]
[the red shift.]
as you just [insist.]
it must be very good.
And there was a silence Dead silence, for a moment [.]
I didn't know whether Hubble had really heard what he said He said: "Well, Mil, Now you're beginning to use the [disk.]
in the way it should be" Humason reported his data in Hale's Astrophysical Journal As the galaxies got fainter, their red shifts got bigger the faintest was the whopper in whose spectrum Humason found appeared in spetral line were completely out of place indicating the whopper was moving incredibly fast They're normally be here Hubble, however, had calculated that the whopper was immensely distant for it's also to be moving so fast, indicated that the universe was flying apart The Big Bang Hubble was cautious.
His paper simply correlated Humason's red shift data and his own distance calculation If something's distant, he said, it would have a big red shift Early in this century, when Einstein was working out his new theory of gravitation he encountered the same problem that Newton had met 2 centuries earlier If all the stars are attracting each other, why doesn't the universe collapse? Now, the resolution of this problem came in a curious way, through the work of Edwin Hubble Hubble found that the universe was so immense that it really didn't matter.
It would take billions of years for the collapse to take place But of course, Hubble found that the universe was expanding An idea so overwhelming that he could hardly bring himself to belive it But Hubble had ,in fact, sampled only around a small part of the universe And the question remained was the rest of the universe like this part On Mt.
Palomar, away from this [spreading light.]
of Los Angeles 2 new telescopes were built to sample still more of the universe One was by far the largest in the world, and the [crowning.]
achievement of George Ellery Hale's career With 6 million dollars, it would have a collecting area 200-inches across 16 tons of glass it took a year for the casting to cool, and another year to be ground to see as clear as possible in the [doom light.]
as Hubble did [could this portray.]
in his [crammed pocket cage.]
Just across the hill, a much smaller dome houses the 48-inch Smith named after its inventor This is a rather special telescope because it was designed exclusively for taking pictures It is, in fact, a giant-sized camera We take the photograph on glass plates which are held in the plate holder like this they can be up to 14 inches on a side and the plate holder actually goes inside the telescope George.
A.
Bell, he was among the Smith's first users Now if you take a look on the tube in the front end You can see the plate holder sitting [at the centre of the.]
projection The particular advantage of this telescope is the grand wide field of view it's more than 6 degrees, and that's not very much for North America camera, but it's a lot for a telescope For the next, the big Smith's ideal as a survey instrument In fact, the first task assigned to the telescope after its completion in 1949 was a complete photographic survey of the entire sky Now, the larger refractor like the 200-inch can pose distant space but only in a very small field of view it would take litterally tens of thousands of years to photograph the whole sky with [100.]
telescope But we did it with just this telescope in under 6 years To give an idea of the scale of the Smith The size of the [.]
image photographed [by.]
the Smith would be about the size of this ten pennies British coin and by the way, we're looking at the photograph that's negative, so that the stars appear dark against the white background This is an image of the Andromeda galaxy It may be visible to the naked eye on an [August.]
night although most people don't know [it is.]
It happens to me as the nearest spiral galaxy to our own the Milky way galaxy, it's pretty much like our own one It has a few smaller companions Companions are the [.]
galaxies, most are not [all.]
galaxies seem to be members of groups of small clusters, perhaps This object, our own galaxy and a couple of dozen others [Big couples.]
were clusters, or a few bit of lightyears across, that we [affectionately.]
call "the local group" Now we scan over magnifying glass or photographs like this taken [with the Smith.]
telescope We can find literally hundreds of millions of images and almost always in groups or clusters, almost never by themselves A [little.]
cluster like our local group but not very obvious at the very great distance of, say, thousands of millions of lightyear but fortunately, every now and then, we find a really great cluster Cluster that stands out like a [.]
thumb containing thousands of member galaxies which is our own Milky Way I can [log.]
almost 3000 [of them.]
And when the distribution of those great clusters came [some.]
in sight It is how matter is distributed throughout space Our own local group is a number of a super clusters that also contain the famous [google.]
cluster of galaxies A pretty rich cluster maybe 30 to 50 millions lightyears away But far beyond our own local super cluster, we found other super clusters The nearest of these really great clusters is [comma.]
cluster of galaxies But if we look over, still larger and further in space We find the hierarchy ends Super cluster seems to be the largest unit in the universe Over extremely large scale compared to the size of a super cluster then we find that one part of the universe seems to be about the same as in the other part Space is remarkably homogeneous It's how we call the cosmological principle The uniform [.]
of the universe on a large scale Another super cluster, and how we're accustomed see it We see it still mostly [stage.]
Within the whole universe, no matter what direction we look, what we see is similar to everywhere else This is the representation on map that has been computer-generated It's based, however, on the nearest one million galaxies It showed the distribution across the sky everywhere the same The universe is uniform The mass cuts off where our telescope horizon is to be to the south and another direction where the star-maps of our Milky Way blocks it out You can see that the galaxies [clutched.]
together and formed random knots The biggest knots, the super clusters seem fairly distributed What this showed is that although the galaxies are flying apart gravity still acts on them While the universe continues to expand, in some places like around our Milky Way Galaxies also fall together But if [we.]
are expanding outward, we're also falling inward How fast are we really moving? and just how far away are the other distant galaxies In Arizona, at the Kitt Peak observatory there's a project to measure the expansion of the universe out beyond our own super cluster how fast the more distant clusters are moving has been known since Hubble's time To find out how far away they are this team is measuring their radio spectra and how bright they are in infra-red light they based their new measurement on the known distances of the nearby galaxies To do this, they use smaller optical telescope [Gemony Nome speaking.]
Oh, this is [Prism.]
telescope We can convert the 16-inch telescope to the [prism.]
telescope by installing this probably one of the smallest telescope currently used in astronomy To observe the more distant galaxies, they use larger telescopes What they've done is to measure what's called the apparent brightness of the distant galaxies using infra-red light Large spiral galaxies are brighter than the small one and also spin more rapidly If you know how fast they're turning, then you can figure out just how bright they must be Using radio measurement, that's just what this team did For a particular galaxy, its distance can be found by comparing its actual brightness to its apparent brightness I think when we began this project We wanted to see whether the expansion [right.]
that we measured was the same for the distant galaxies as the nearby galaxies And the principle is all about what had been surprising [London/Doppler.]
effect Distant galaxies are moving apart considerably faster than we expected from nearby galaxies Mark Ericson: The result [that.]
we have seems to [make it there.]
While universe as a whole was probably going on expanding forever Our super cluster may in fact stop expanding and eventually starts to contract and one day, our local group may pass through the virtual cluster, stop Our local group appears its bound and it's not part taking in the expansion, look at the Andromeda, in fact The Andromeda Galaxy isn't moving away from us, it's moving toward us This is the model of the universe computered in Cambridge, England Several thousand galaxies have been distributed at random in the computer each one through gravity is falling on all the rest Above all, it's rotated so we can get a greater [stand.]
of [depth.]
After a few billion computer-years, knots of matters do [form.]
how soon this happens [depend.]
on the distribution of the stars For the real universe, we know very little about that beginning distribution about what it was like in the time of the Big Bang In a universe that might expand forever, this model investigates how local clusters can form while the whole system continues to fly apart gravitation brings some parts together just as what we see to be doing inside our local cluster When we look deeper into the space, we're looking back [in the time.]
But even with the Palomar telescope we can see ordinary galaxies only half way back in the beginning of time what was the universe looks like ten billion years ago, when it's [new.]
To answer that question require another kind of astronomy and different instrument You see me here by visible light If the room were dark, and you have the right detector you can find me with the longer infra-red wavelength and if you have a very sensitive radio detector you would find that my body still absorb a very faint radio static But to examine the universe in the longer radio length with the same [maturity.]
with the visible light, requires a very large instrument The latest and largest of these instruments is this That's just one element in the [.]
They're all radiowave-receivers spreading across the desert in New Mexico There are 28 in all Each dish is one part of a much larger telescope As the Earth rotates, the dishes rotate with it all the while receiving signal over a period of time, they add up to one huge disk each arm is 11 miles long it's call, simply.
the Very Large Array it's a radio-Y nearly 20-miles across The very large array is controlled by computers One bank drives and points all the dishes Another send [extracts.]
the signal from all the background noise A 3rd group processes the signal to put together an image A picture the eye can wholly recognize The object they review can be quite unusual We receive [499.]
a radio galaxy [.]
commonly, radio jet There's a galaxy at the centre with a pair of jets, it seems to pull around through space Some of the images, however, are more familiar.
Here's the Whirlpool again Its spiral structure shows up clearly Radio astronomy is well-established now, but its [unauthorised contraction.]
took a while to be accepted An early pioneer in Australia was John Bolton Well [.]
my first 2 years in radio astronomy The conventional optical astronomers didn't in fact believe that the radio signals we're solving were from how far it's told I spent my time during War as a Radio Officer the Royal Navy has been [.]
research and part of its [operation.]
And one other thing which changed the optimum range at which one can detect [the German Aircraft.]
with [.]
the Milky Way, [.]
horizon in [.]
Model And so to me, [extra-red.]
radio emission was a very genuine thing And after all, I got the oppotunity of radio physics to try and split up this broad band of radiation into discrete objects And, I mean I look at this radiation from outter space with just the same belief when the conventional astronomers look at the stars and believe they're there Bolton's early reports that some kinds of galaxies send out powerful radio waves initiated a vast new field to study The advantage of radiowave is that they penetrate the atmosphere whether cloudy or clear to reach us here on Earth Even the sun doesn't interfere, so observation can be made by day or night Huge receivers have been built all over the world One in West Virginia is 300 feet in diameter And in the [natural bowl.]
at Arecibo, Puerto Ricco this dish is 1000-feet across Here they collect the faintest signals in the world Images with a better resolution, however, come from the space receivers This one in Holland found the largest galaxy known In studying huge galaxies like these radio allows us to see further toward the edge of the universe that we can't see with ordinary light Radio telescopes open another new field to discover In Australia in 1963 Cyril Hazard pinpointed the coordinates of a small but bright radio source With the conventional telescope, he found it a faint, blue star-like object It was the first glimpse of something previously unsuspected Crazy Stellar Sources now called quasars The Palomar 200-inch also plays an important part in the discovery of quasars Martin Smith and [Beb Hope.]
measured the new objects' red shift and found it to be almost unbelievable The object must be a vast distance away More energy than the whole galaxy release was coming from a region as small as our solar system For Smith, this is what the 200-inch was for It discovered that at enormous distances, when the universe was 1/5 its present age there were many more quasars than in more recent time Further away, there are none at all They seem to have been formed early, and many have already come to an end A [.]
collaboration developed The optical astronomers search where the visible counter-part of the powerful radio-sources found by radio-astronomer like John Bolton Astronomers can now locate quasars more easily than when they were first discovered One way is with this Smith telescope that was built to map the Southern sky from Australia A speacially designed prism can be attached to a part of this telescope The [wide.]
shaped prism bends the light Seen through the prism, the colors spread apart Stars, galaxies and quasars can be distinguished by their spectra and distant galaxies have all its spectral light shifted toward the red But as it's made up of seperate stars, all moving at different speed the galaxy as a whole has [smugges.]
instead of neat light A quasar on the other hand glows with bright [ignition.]
light like a ferocious lamp Astronomers can easily see these differences using Smith's prism plate Black and white photography records the faint images and because the prism element is up-front hundreds of objects can be distinguished with one exposure the quasars can be [picked.]
down by eye [John Doore.]
We're now looking at a quasar with 2 [emissional features.]
The one in the centre is due to Hydrogen and to the right end of the spectrum, we see an emission of [Carbon.]
Since they were first discovered, a few thousands quasars have been recorded But what is their source of energy? and how did they relate to galaxy? Some insight comes when studies of active galaxies such as the M87 a giant elliptical that has strong X-ray as radio source Alec Boksenberg: You know that it's got a jet [bear.]
to the left And let's first look at it without galaxy and, just the jet Now by a sort of a trick, we subtracted the galaxy There's a lot of energy in that jet, simply the mass [emotion.]
The point about the centre region is that not only it's bright in comparison with the rest, but also we can tell that the stars in the vicinity of this centre region are moving with all the chaostic motion The way we do this is to observe the spectrum of the galaxy and we can do that with this cursor and that region now showed here represents the slit, which is a long slit of a spectrograph which we use to spread out the light that's passing through this [narrow split.]
region into what are now the colors of the rainbow In fact, colours here at the top are represented as the blue, and down here red M87 itself, very strong features here which I can show more clearly like that, are due to the Calcium lines Most stars in the galaxy have those particular lines but they are always narrower than they appear in the M87 And the reason for that is we are [causing.]
for more than one star and near the centre They are increasing in speed, very rapidly And what we can infer from this is that in the centre of M87, there is a very large mass which is causing the stars to move in this chaostic passion So we have a very large mass, But not bright enough to be stars, in other words, it's a dark mass Also very compact, and we are ready led to saying: There is, in M87 A Black Hole in the Centre We see two galaxies both of which are spectacular radio sources which seem to contain this mass concentration which is probably a black hole And we suspect that there is in fact such an object in the centre of nearly every large galaxy And, at one time, you see every galaxy which had been a quasar that now, with the density of the universe decreasing with time the rate at which you can fit the black hole's mass has decreased so the quasar has died out the stars of mass we no longer see active quasar, but only dead remnants, and we suspect that if you look at the centre of any large galaxy you'll see a remnant quasar Here's an active quasar that Alec Boksenberg has studied Above it is a star in our galaxy, it looks much the same as the quasar When the exposure increases, however, the quasar get disproportionately bigger In fact, there's a galaxy surrounding it The quasar gave us a new view of the universe a universe filled with violence than its younger day Not everyone agrees with that view, that the quasars are very far away, that challenge us something about the early history of the universe There's even been a public debate, an echo of that confrontation back in the 1920s Perhaps we just don't yet have enough historical perspective we have a lot of problems, does the universe expand forever or collapse again Are there black hole in the [nuclear eye.]
of galaxies, perhaps even in our own And we have very exciting new instrumentations But we just don't know which instrumentation will solve which problem The Anglo-Australian telescope in the Warrumbungle mountains of New South Wales is among the many new instrumentations and different techniques that astronomers are using today The telescope itself looks conventional in design It's smaller than the 200-inch at Palomar It's 162-inches But like all the major telescopes, it uses powerful light detector that enhances its performance to become the equivalent of maybe a thousand inches across The new electronic detectors are remote-controlled by the computer [.]
at the time when observers spent their night out on the telescope itself The electronic revolution may have taken some of the romance out of observing the universe but it's possible now to see farther and fainter and for brighter objects, to see many more in a night the telescope finds its own way This is what it sees It's found the object it's looking for and with great precision, we'll follow it across the night sky In the control room, our remote view finder shows what the telescope is looking at Alec Boksenberg developed an imaging detector for quantitative work that records individual photons of light It uses a 4-stage image intensifier that increases the strength of the incoming light some ten millions time Then each photon event is located and recored electronically As seen in real time, a galaxy doesn't give much of a picture though you can just make out a shape For fainter galaxy, there is even less light coming in Now you can no longer tell the shape But building up a picture over a long exposure time is a simple job for the computer Now, this is how the picture is built up in the computer Alec Boksenberg for these individual photons the computer accepts each photon event, recorded in its memory and now the display shows how the information is accumulating For some applications, photography is still the best way At the Anglo-Australian observatory, research photographer [David Melon.]
has been using a multiple exposure technique to obtain accurate colors Ordinary film is blind incertain Because even with a human telescope, no human eye can see such scene Taking seperate exposures and different color ranges reviews in the arm of this distant spiral the red knots of gases in which stars are forming and the brilliant blue of massive young stars sprinkle among its [swarm.]
of others like our own Sun A kind of [lifelike.]
could possibly live there but that's a rare hint of familiarity in the universe that we still know so little about Even more ordinary photographs may be made to yield new information Using original plates with smooth, centre star mass of the Centaurus galaxy can be mapped out to review detail that's hidden beneath Here they were interested in the rings, its [dust trail.]
that's been circling This is the same galaxy again, Centaurus A But now the space around it contain a ghostly traces of a round, more fainter star With the second technique, this elliptical galaxy can be seemed to be actually larger and with a jet and a reasonably smooth spiral becomes irregular in shape This is a small elliptical galaxy it has a shell that's only recently been noticed a vast array of stars form a wall way out in space No one knows what caused it.
A [ripple.]
from some collision or wave through a gas cloud from which the stars condense These kinds of questions have been investigated by computer, here in the work of MIT Mathematican Alan Turing Galaxies may be masses, but they're actually mostly just space As a few hundred years go by, there's no actual collision But this [titled.]
interaction opens out its spiral arm We've seen this shape before More often, these spirals are angled the Milky Way and Andromeda galaxy might interact like this These two have already happened elsewhere in the heaven Galaxies do collide, what astronomers don't know is the role of such collision in the evolution of galaxies Did spirals collide to form other types? or Do ellipticals slowly develop spirals around them What the history of astronomy has shown over and over again is that the old problems are solved in remarkable and unexpected ways by new technology The photographic plate.
The Spectrograph.
The 100-inch refractor.
Radio Telescope but so far, we aren't running out of problems because the new technology and instrumentation lead us to new phenomena bewildering, scarcely understood One problem recently brought together the resources of stellar institution, new instruments and theoretical work A quasar whose images split in two by gravitational lens was discovered at Jodrell Bank in England Well, it began about 8 years ago, when a group of collegues and I started the survey of radio sources using the [100 metre tall.]
telescope here And we measured actual radio positions so that we could find the [corresponding.]
optical object And many hundreds of these including galaxies and quasars The new quasar appeared as a double image barely resound on the plate from the Palomar Smith Larger telescopes poorly resound them Two distinct images seperated by a 1/600 degree From the quasar on the left, light passes a massive galaxy so close that it's bent And its rays reach us here on Earth by two seperate paths So we see the quasar in two seperate places in the sky The galaxy in the centre act as a gravitational lens a phenomenon predicted by Einstein's General Theory of Relativity From one of the highest observatories on Earth Alan start in Hawaii [.]
obtained a double image that could be processed to remove one quasar revealing the galaxy that split the light the galaxy images faint, it was swarmed by the quasar But now they could see it on its own Just before starting the observation , the team at [.]
also photographed the quasar, using a powerful new detector system This silicon diode array constructs an electronic image that can be displayed directly on a TV screen These were their images This gravity lens established that at least this one quasar had to be very distant But it also provided the means that were driving the mass of the galaxy that bent the light The next technological step for astronomy is to see the galaxies more clearly and to see them deeper in space we're still at the problem of [over.]
atmosphere, that should be a sharp, tiny dot But in the next few years, the space shuttle is scheduled to take an optical telescope with a 54 inch mirror into orbit the stars and the galaxies will be ten times sharper It was an earlier time when that kind of a joke happened, the night when Galileo first started using a telescope himself, just the eyeball and the telescope [Jims Wetsbond.]
First, the simple fact that we see things ten times sharper means that we can examine a galaxy ten times further away it also allows us to see things that are fainter by a factor, may be on the order of 50 But new telescopes are still needed down on the ground However sharp the image, one 54 inch mirror isn't enough for all the questions that remain unresolved This multi-mirror telescope is the first of a new kind with 6 refractors, each the size of Lord Rosse's Leviathan it adds up to the equivalent of 176 inches that's somewhat less than Palomar, but the structure that supports it is smaller in comparison and its cost is correspondingly low this multi-mirror telescope was built just in time for the best early study of the spectrum of the double quasar to show that the two images were really identical On Mount Hopkins in Arizona, this successful new design sent the past toward more to come Verged on its [spinical.]
of 8500 feet The multi-mirror telescope achieved some of the steadiest images in North America essential for cosmoslogical study To see even better image quality astronomers are willing to go the ends of the Earth At nearly 14000 feet, on the rhyme of Maunea Kea in Hawaii is an international collection of telescopes the most powerful or [greatest.]
one has been especially designed to collect the infra-red Here, too, cast is important Its optically excellent 4-meter mirror has been cast unusually thin weighing tons less than usual, its supporting structure was also much cheaper to build And for their purposes, the bright sunny sky doesn't block out their views, they can observe in the daytime as well These efficient new telescopes offer new hopes of further discoveries hopes of new insights into the nature of the universe and our place in it What the history of astronomy had shown over and over again is that the old problems are solved in remarkable and unexpected way by new technology The photographic plate.
The Spectrograph.
The 100-inch refractor.
Radio Telescope But so far, we aren't running out of problems, because the new technology and instrumentation lead us to new phenomena, bewildering scarcely understood From our earliest beginning, we have looked at the stars and wondered some of our oldest [counter.]
facts are the tools we used to try to measure the turning of the sky whether in the company of priests, or scientists or dreamers we are still searching for our place in the heaven
Earth Passed this galaxy in Andromeda are as many more as there are stars in our own Milky Way Dozens of galaxies for every person now alive and each is as distinctive as an individual face This one, the Whirlpool inspired our beginning understanding Its curious shape was discovered here in Centre Ireland, by William Parksons, the 3rd Earl of Rosse This is his descendant - the present day Seventh Earl of Rosse looking over the remains of what had been known as The Laviathan ParksonsTown These high walls supported the wooden cylinder that, for 70 years, held the biggest telescope on Earth You can walk inside it with a raised umbrella In fact, at the opening celebration in 1945 Its huge size was properly demonstrated in just this way The tube was movable as this scaled model shows It could be winched up vertically and, within limits, to the side But just like this smaller version, it all had to be done by hand Its main mirror was 6 feet across - 72 inches It was made of metal, cast [on the side.]
and then carefully ground and polished With time, it began to turnish Lord Rosse's hope was that with this monster telescope he would solve the puzzle posed by certain tangent fuzzy objects called 'nebulae' The Whirlpool was one, what were they? After 2 years of delay because of the potato fermine and despite the often cloudy Irish sky Lord Rosse observed and sketched this particular spiral structure again and again Its eye probably across the sky as the Earth turns on its axis 3 workmen moving the huge tube between its supporting walls Pioneer photographer such as Lady Rosse took pictures of the telescope and its visitors But they didn't yet think to try photographing the heaven In his sketches, we all distinguish between certain of nebulea and the spiral He posed question about the structure and their place in nature that could not then be resolved How large were they? How far away? Could they be island universes as some philosophers had speculated At the Harvard Smithsonian Centre for astrophysics historian of astronomy, Professor Owen Gingerich This thin wheel is a scaled model of our Milky Way Spiral a thin disk of stars, a giant system of more than 100 billion stars like the sun and smaller and with a dazzling [spotting.]
of much brighter stars that make up the spiral arms of the Milky Way It's about a 100 thousand-lightyears across and the sun is an average star in here Of course, Lord Rosse [hasn't the foggiest.]
idea of the [great extent.]
of the Milky Way and he didn't know how the spirals and the other nebulea fit in He was a natural historian classifying the nebulea wondering what they were made of whether they evolve Quite surprisingly, some of the answers to these questions came from instruments quite a bit smaller than his At the same time that Lord Rosse was finding the first spiral with the Liviathan Parksonstown this telescope was being erected at Harvard This and its twin at Saint Petersburg, in Russia were the largest refractors in the world Sitting in this chair, the astronomer George Bond made the observation for the finest drawing of the nebula, the Orion nebula, ever made But also here began that change of event that made drawing the nebulea obsolete Because here in 1850 was taken the first photograph of a star And before that decade was out, they had made wet plate of the Moon and of the planets But not until the 1880s when dry plate became available did astronomers take up photography with such enthusiasm With that new tool, with the permanent record astronomers found that they just couldn't detect directly any large scale evolution of the nebulea But whether the spirals were great congregated stars or something else That answer came from another [quarter.]
from spectroscopy when starlight is passed through a prism to form a spectrum among those leading pioneers was a mid-Victorian amateur [independant mean.]
William Huggins who set up a telescope on the second floor of his home near London With the spectrogram attached to his telescope Huggins found that the spectra of the [more.]
gaseous nebulea like the Orion nebula [consistent to.]
the bright light characteristic of tenuous gas But the spirals were much fainter and harder to photograph and not until the end of the century could Huggins showed that they had different spectra much brighter those in the sun and stars A star's spectrum has dark light where its light has been absorbed by cooler gases at the star's surface Huggins believed that the spirals were made up of stars but to answer that decisivey required more light-gathering power George Ellery's huge ambition was to chart the evolution of the universe to be, or possibly to find the [dark.]
one of the cosmos with a little help from his friends like Andrew Carnegie he had a [cyclo.]
near Los Angeles At the end of a winding trail on Mount Winston, the observatory dome was built to the height of 5000 feet with the 16 inch mirror made of glass the telescope was a little smaller than Lord Rosse's but it was far more versatile and it's still in use today New electric model was used to move the instrument In 1909, when it came into use, it was still unknown what the spiral nebulea were the telescope's mirror at the bottom gathers up the light and focuses it back toward the top from there it is reflected back down again to an angled mirror here The objective [.]
was sighted and a photographic plate was inserted to capture the image the object was then [pract.]
by choosing a star off to one side and keeping it [light.]
on target for the rest of the night, or even for the rest of the week Hale had already collected the money for an even a larger instrument and had chosen a sight for it nearby A second dome was built to house 100-inch mirror it would have twice the collecting power of Lord Rosse's telescope And would be the first to surpass its inside This is the instrument that should finally review what the spiral nebulea were [Early.]
little was actually known yet As the 100-inch came into use by the end of the first world war the spirals had become the subject of acrimoniest debate among astronomers the most basic questions had no agreed answers were they bright objects far away? or faint objects close by? Estimates of the distance of objects in the sky depend on a very complex chain of reasoning of which one vital [link.]
was found here in this building of the Harvard Observatory Here at the turn of the century, a woman named Henrietta Leavitt made a fundamental discovery by scanning numerous photographic plate for variable stars In Hen' Levitt's day, these plate stacks were considerably small than the other day but then as now, they housed a treasury of stellar images from both the Northern and Southern sky The plates had found choronogically and in this section are those taken in 1904 and 1905 which Henrietta Levitt used for her searches for variable stars this's a plate of the large Magellanic cloud one that was used by Ms.
Levitt in the early 1900s From this peppering of literally thousands of stars she found a few that systematically [rhythmically.]
varied in brightness, the Cepheids And then she made her key discovery that the brighter the star was, the longer it took to them to pulsate Just about this time, a young Missourian named Harlow Shapley out at Mt.
Wilson observatory was studying globular star cluster and the structure of the Milky Way the tightly packed congregration of hundreds of thousands of stars here they're marked with the circle and he found that they tended to be concentrated in a very small section, 1/3 of all known globular clusters in just 5% of the sky He wanted to find out how far away they were and for this, he made the assumption that Cepheid variable stars pulsating with the given period, say, 10 days were the same wherever they were found throughout the entire universe so he calibrated their absolute brightnesses and found how far away they were Now, at the time Shapley was starting his study of the globular star clusters astromoners believed that the Milky Way was a rather small sun-centered system but when Shapley found out that the globular clusters are the [middle action.]
were tens of thousands of lightyear away he decided that the Milky Way must be an enormous disk perhaps a hundred thousands lightyear across This was so enormously bigger, staggeringly larger than anybody had imagined that Shapley thought that this was all there were, the globular clusters, the stars, the spirals, everything but his critics were not so sure they thought that Shapley had radically overestimated the size of the Milky Way and many of them thought the spirals were actually independent island universes very far away And this all culminated in a very sharp debate before the National Academy of Sciences in April, 1920 Now, today we know Shapley was quite right about the size of the Milky Way but completely wrong about the distance to the spiral but in 1920, it was going to take some new and fresh observation to settle that matter At Mt.
Wilston, Edwin Hubble, a young astronomer hired by Hale, already suspected what was needed By [trailing.]
the 100-inch telescope on the biggest spiral nebulea he should be able to distinguish individual stars With these stars, he can estimate distance he [perceived.]
it meticulously step by step when one glorious piece of luck intervened he had been searching the Andromeda spiral for novae stars that brighten suddenly, then die away one of them brightened again, it was a variable, not a nova it had varied in the same way that Cepheid variables did he could assumes that it was one, too It did Hubble now knew its basic brightness so he could measure its distance reliably It lay far beyond our own Milky Way [And he.]
established that other nebulea do exist and that they lie outside our own Hubble classified their types Many are elliptical in shape, some round, some more flat some are vast, others relatively small there are the spirals, a fuzzy [.]
spreading range and we see each kind at all different angle Hubble wondered whether these represented different stages along some lines of development A 3rd class has what looks like a bar across the hub they're barred spirals many others [just not fit.]
they're undefined shape, Hubble called them the irregulars some are so unusual that today they're called peculiar galaxies Hubble continued [.]
to find out how far away galaxies are he also studied their spectra the spectral line of the galaxies are shifted, generally toward the red like the falling sound of a passing train the pitch of light, the distance between its waves spreads out the faster its source moves away to attain and measure these red shifts, Hubble needed help Milton L.
Humason came to Mt.
Wilson as a mule driver he brought up materials to build the telescope, then learned to use it one of Humason's graduate students in 1925 was Nick Male The exposure was very long, nearly a week sometimes and so the occasion of taking the plate out [in the vaulting.]
was a real traumatic offer and he invited me to come in one very very morning he cracked the door, he said he was gonna [vault.]
this plate without, would I like to be with him [He.]
carefully preserved the actual plate they took He turned on a red light and grabbed the microscope and held it up to enlighten a glass box and he looked at it, he said "My God, [there.]
we got a whopper" The whopper was the spectrum of the galaxy Hubble had estimated was very distant He'd asked Humason to check its red shift So Humason called up Hubble [after.]
dinner and asked [him.]
to pick up an [expulsion.]
so I heard the conversation right from the beginning And they said: "[.]
called the [Mr.
Hubble.]
" And Humason said:"Mr.
Hubble, you are right again.
You had it right [on the note.]
" we have twice [as large.]
[the red shift.]
as you just [insist.]
it must be very good.
And there was a silence Dead silence, for a moment [.]
I didn't know whether Hubble had really heard what he said He said: "Well, Mil, Now you're beginning to use the [disk.]
in the way it should be" Humason reported his data in Hale's Astrophysical Journal As the galaxies got fainter, their red shifts got bigger the faintest was the whopper in whose spectrum Humason found appeared in spetral line were completely out of place indicating the whopper was moving incredibly fast They're normally be here Hubble, however, had calculated that the whopper was immensely distant for it's also to be moving so fast, indicated that the universe was flying apart The Big Bang Hubble was cautious.
His paper simply correlated Humason's red shift data and his own distance calculation If something's distant, he said, it would have a big red shift Early in this century, when Einstein was working out his new theory of gravitation he encountered the same problem that Newton had met 2 centuries earlier If all the stars are attracting each other, why doesn't the universe collapse? Now, the resolution of this problem came in a curious way, through the work of Edwin Hubble Hubble found that the universe was so immense that it really didn't matter.
It would take billions of years for the collapse to take place But of course, Hubble found that the universe was expanding An idea so overwhelming that he could hardly bring himself to belive it But Hubble had ,in fact, sampled only around a small part of the universe And the question remained was the rest of the universe like this part On Mt.
Palomar, away from this [spreading light.]
of Los Angeles 2 new telescopes were built to sample still more of the universe One was by far the largest in the world, and the [crowning.]
achievement of George Ellery Hale's career With 6 million dollars, it would have a collecting area 200-inches across 16 tons of glass it took a year for the casting to cool, and another year to be ground to see as clear as possible in the [doom light.]
as Hubble did [could this portray.]
in his [crammed pocket cage.]
Just across the hill, a much smaller dome houses the 48-inch Smith named after its inventor This is a rather special telescope because it was designed exclusively for taking pictures It is, in fact, a giant-sized camera We take the photograph on glass plates which are held in the plate holder like this they can be up to 14 inches on a side and the plate holder actually goes inside the telescope George.
A.
Bell, he was among the Smith's first users Now if you take a look on the tube in the front end You can see the plate holder sitting [at the centre of the.]
projection The particular advantage of this telescope is the grand wide field of view it's more than 6 degrees, and that's not very much for North America camera, but it's a lot for a telescope For the next, the big Smith's ideal as a survey instrument In fact, the first task assigned to the telescope after its completion in 1949 was a complete photographic survey of the entire sky Now, the larger refractor like the 200-inch can pose distant space but only in a very small field of view it would take litterally tens of thousands of years to photograph the whole sky with [100.]
telescope But we did it with just this telescope in under 6 years To give an idea of the scale of the Smith The size of the [.]
image photographed [by.]
the Smith would be about the size of this ten pennies British coin and by the way, we're looking at the photograph that's negative, so that the stars appear dark against the white background This is an image of the Andromeda galaxy It may be visible to the naked eye on an [August.]
night although most people don't know [it is.]
It happens to me as the nearest spiral galaxy to our own the Milky way galaxy, it's pretty much like our own one It has a few smaller companions Companions are the [.]
galaxies, most are not [all.]
galaxies seem to be members of groups of small clusters, perhaps This object, our own galaxy and a couple of dozen others [Big couples.]
were clusters, or a few bit of lightyears across, that we [affectionately.]
call "the local group" Now we scan over magnifying glass or photographs like this taken [with the Smith.]
telescope We can find literally hundreds of millions of images and almost always in groups or clusters, almost never by themselves A [little.]
cluster like our local group but not very obvious at the very great distance of, say, thousands of millions of lightyear but fortunately, every now and then, we find a really great cluster Cluster that stands out like a [.]
thumb containing thousands of member galaxies which is our own Milky Way I can [log.]
almost 3000 [of them.]
And when the distribution of those great clusters came [some.]
in sight It is how matter is distributed throughout space Our own local group is a number of a super clusters that also contain the famous [google.]
cluster of galaxies A pretty rich cluster maybe 30 to 50 millions lightyears away But far beyond our own local super cluster, we found other super clusters The nearest of these really great clusters is [comma.]
cluster of galaxies But if we look over, still larger and further in space We find the hierarchy ends Super cluster seems to be the largest unit in the universe Over extremely large scale compared to the size of a super cluster then we find that one part of the universe seems to be about the same as in the other part Space is remarkably homogeneous It's how we call the cosmological principle The uniform [.]
of the universe on a large scale Another super cluster, and how we're accustomed see it We see it still mostly [stage.]
Within the whole universe, no matter what direction we look, what we see is similar to everywhere else This is the representation on map that has been computer-generated It's based, however, on the nearest one million galaxies It showed the distribution across the sky everywhere the same The universe is uniform The mass cuts off where our telescope horizon is to be to the south and another direction where the star-maps of our Milky Way blocks it out You can see that the galaxies [clutched.]
together and formed random knots The biggest knots, the super clusters seem fairly distributed What this showed is that although the galaxies are flying apart gravity still acts on them While the universe continues to expand, in some places like around our Milky Way Galaxies also fall together But if [we.]
are expanding outward, we're also falling inward How fast are we really moving? and just how far away are the other distant galaxies In Arizona, at the Kitt Peak observatory there's a project to measure the expansion of the universe out beyond our own super cluster how fast the more distant clusters are moving has been known since Hubble's time To find out how far away they are this team is measuring their radio spectra and how bright they are in infra-red light they based their new measurement on the known distances of the nearby galaxies To do this, they use smaller optical telescope [Gemony Nome speaking.]
Oh, this is [Prism.]
telescope We can convert the 16-inch telescope to the [prism.]
telescope by installing this probably one of the smallest telescope currently used in astronomy To observe the more distant galaxies, they use larger telescopes What they've done is to measure what's called the apparent brightness of the distant galaxies using infra-red light Large spiral galaxies are brighter than the small one and also spin more rapidly If you know how fast they're turning, then you can figure out just how bright they must be Using radio measurement, that's just what this team did For a particular galaxy, its distance can be found by comparing its actual brightness to its apparent brightness I think when we began this project We wanted to see whether the expansion [right.]
that we measured was the same for the distant galaxies as the nearby galaxies And the principle is all about what had been surprising [London/Doppler.]
effect Distant galaxies are moving apart considerably faster than we expected from nearby galaxies Mark Ericson: The result [that.]
we have seems to [make it there.]
While universe as a whole was probably going on expanding forever Our super cluster may in fact stop expanding and eventually starts to contract and one day, our local group may pass through the virtual cluster, stop Our local group appears its bound and it's not part taking in the expansion, look at the Andromeda, in fact The Andromeda Galaxy isn't moving away from us, it's moving toward us This is the model of the universe computered in Cambridge, England Several thousand galaxies have been distributed at random in the computer each one through gravity is falling on all the rest Above all, it's rotated so we can get a greater [stand.]
of [depth.]
After a few billion computer-years, knots of matters do [form.]
how soon this happens [depend.]
on the distribution of the stars For the real universe, we know very little about that beginning distribution about what it was like in the time of the Big Bang In a universe that might expand forever, this model investigates how local clusters can form while the whole system continues to fly apart gravitation brings some parts together just as what we see to be doing inside our local cluster When we look deeper into the space, we're looking back [in the time.]
But even with the Palomar telescope we can see ordinary galaxies only half way back in the beginning of time what was the universe looks like ten billion years ago, when it's [new.]
To answer that question require another kind of astronomy and different instrument You see me here by visible light If the room were dark, and you have the right detector you can find me with the longer infra-red wavelength and if you have a very sensitive radio detector you would find that my body still absorb a very faint radio static But to examine the universe in the longer radio length with the same [maturity.]
with the visible light, requires a very large instrument The latest and largest of these instruments is this That's just one element in the [.]
They're all radiowave-receivers spreading across the desert in New Mexico There are 28 in all Each dish is one part of a much larger telescope As the Earth rotates, the dishes rotate with it all the while receiving signal over a period of time, they add up to one huge disk each arm is 11 miles long it's call, simply.
the Very Large Array it's a radio-Y nearly 20-miles across The very large array is controlled by computers One bank drives and points all the dishes Another send [extracts.]
the signal from all the background noise A 3rd group processes the signal to put together an image A picture the eye can wholly recognize The object they review can be quite unusual We receive [499.]
a radio galaxy [.]
commonly, radio jet There's a galaxy at the centre with a pair of jets, it seems to pull around through space Some of the images, however, are more familiar.
Here's the Whirlpool again Its spiral structure shows up clearly Radio astronomy is well-established now, but its [unauthorised contraction.]
took a while to be accepted An early pioneer in Australia was John Bolton Well [.]
my first 2 years in radio astronomy The conventional optical astronomers didn't in fact believe that the radio signals we're solving were from how far it's told I spent my time during War as a Radio Officer the Royal Navy has been [.]
research and part of its [operation.]
And one other thing which changed the optimum range at which one can detect [the German Aircraft.]
with [.]
the Milky Way, [.]
horizon in [.]
Model And so to me, [extra-red.]
radio emission was a very genuine thing And after all, I got the oppotunity of radio physics to try and split up this broad band of radiation into discrete objects And, I mean I look at this radiation from outter space with just the same belief when the conventional astronomers look at the stars and believe they're there Bolton's early reports that some kinds of galaxies send out powerful radio waves initiated a vast new field to study The advantage of radiowave is that they penetrate the atmosphere whether cloudy or clear to reach us here on Earth Even the sun doesn't interfere, so observation can be made by day or night Huge receivers have been built all over the world One in West Virginia is 300 feet in diameter And in the [natural bowl.]
at Arecibo, Puerto Ricco this dish is 1000-feet across Here they collect the faintest signals in the world Images with a better resolution, however, come from the space receivers This one in Holland found the largest galaxy known In studying huge galaxies like these radio allows us to see further toward the edge of the universe that we can't see with ordinary light Radio telescopes open another new field to discover In Australia in 1963 Cyril Hazard pinpointed the coordinates of a small but bright radio source With the conventional telescope, he found it a faint, blue star-like object It was the first glimpse of something previously unsuspected Crazy Stellar Sources now called quasars The Palomar 200-inch also plays an important part in the discovery of quasars Martin Smith and [Beb Hope.]
measured the new objects' red shift and found it to be almost unbelievable The object must be a vast distance away More energy than the whole galaxy release was coming from a region as small as our solar system For Smith, this is what the 200-inch was for It discovered that at enormous distances, when the universe was 1/5 its present age there were many more quasars than in more recent time Further away, there are none at all They seem to have been formed early, and many have already come to an end A [.]
collaboration developed The optical astronomers search where the visible counter-part of the powerful radio-sources found by radio-astronomer like John Bolton Astronomers can now locate quasars more easily than when they were first discovered One way is with this Smith telescope that was built to map the Southern sky from Australia A speacially designed prism can be attached to a part of this telescope The [wide.]
shaped prism bends the light Seen through the prism, the colors spread apart Stars, galaxies and quasars can be distinguished by their spectra and distant galaxies have all its spectral light shifted toward the red But as it's made up of seperate stars, all moving at different speed the galaxy as a whole has [smugges.]
instead of neat light A quasar on the other hand glows with bright [ignition.]
light like a ferocious lamp Astronomers can easily see these differences using Smith's prism plate Black and white photography records the faint images and because the prism element is up-front hundreds of objects can be distinguished with one exposure the quasars can be [picked.]
down by eye [John Doore.]
We're now looking at a quasar with 2 [emissional features.]
The one in the centre is due to Hydrogen and to the right end of the spectrum, we see an emission of [Carbon.]
Since they were first discovered, a few thousands quasars have been recorded But what is their source of energy? and how did they relate to galaxy? Some insight comes when studies of active galaxies such as the M87 a giant elliptical that has strong X-ray as radio source Alec Boksenberg: You know that it's got a jet [bear.]
to the left And let's first look at it without galaxy and, just the jet Now by a sort of a trick, we subtracted the galaxy There's a lot of energy in that jet, simply the mass [emotion.]
The point about the centre region is that not only it's bright in comparison with the rest, but also we can tell that the stars in the vicinity of this centre region are moving with all the chaostic motion The way we do this is to observe the spectrum of the galaxy and we can do that with this cursor and that region now showed here represents the slit, which is a long slit of a spectrograph which we use to spread out the light that's passing through this [narrow split.]
region into what are now the colors of the rainbow In fact, colours here at the top are represented as the blue, and down here red M87 itself, very strong features here which I can show more clearly like that, are due to the Calcium lines Most stars in the galaxy have those particular lines but they are always narrower than they appear in the M87 And the reason for that is we are [causing.]
for more than one star and near the centre They are increasing in speed, very rapidly And what we can infer from this is that in the centre of M87, there is a very large mass which is causing the stars to move in this chaostic passion So we have a very large mass, But not bright enough to be stars, in other words, it's a dark mass Also very compact, and we are ready led to saying: There is, in M87 A Black Hole in the Centre We see two galaxies both of which are spectacular radio sources which seem to contain this mass concentration which is probably a black hole And we suspect that there is in fact such an object in the centre of nearly every large galaxy And, at one time, you see every galaxy which had been a quasar that now, with the density of the universe decreasing with time the rate at which you can fit the black hole's mass has decreased so the quasar has died out the stars of mass we no longer see active quasar, but only dead remnants, and we suspect that if you look at the centre of any large galaxy you'll see a remnant quasar Here's an active quasar that Alec Boksenberg has studied Above it is a star in our galaxy, it looks much the same as the quasar When the exposure increases, however, the quasar get disproportionately bigger In fact, there's a galaxy surrounding it The quasar gave us a new view of the universe a universe filled with violence than its younger day Not everyone agrees with that view, that the quasars are very far away, that challenge us something about the early history of the universe There's even been a public debate, an echo of that confrontation back in the 1920s Perhaps we just don't yet have enough historical perspective we have a lot of problems, does the universe expand forever or collapse again Are there black hole in the [nuclear eye.]
of galaxies, perhaps even in our own And we have very exciting new instrumentations But we just don't know which instrumentation will solve which problem The Anglo-Australian telescope in the Warrumbungle mountains of New South Wales is among the many new instrumentations and different techniques that astronomers are using today The telescope itself looks conventional in design It's smaller than the 200-inch at Palomar It's 162-inches But like all the major telescopes, it uses powerful light detector that enhances its performance to become the equivalent of maybe a thousand inches across The new electronic detectors are remote-controlled by the computer [.]
at the time when observers spent their night out on the telescope itself The electronic revolution may have taken some of the romance out of observing the universe but it's possible now to see farther and fainter and for brighter objects, to see many more in a night the telescope finds its own way This is what it sees It's found the object it's looking for and with great precision, we'll follow it across the night sky In the control room, our remote view finder shows what the telescope is looking at Alec Boksenberg developed an imaging detector for quantitative work that records individual photons of light It uses a 4-stage image intensifier that increases the strength of the incoming light some ten millions time Then each photon event is located and recored electronically As seen in real time, a galaxy doesn't give much of a picture though you can just make out a shape For fainter galaxy, there is even less light coming in Now you can no longer tell the shape But building up a picture over a long exposure time is a simple job for the computer Now, this is how the picture is built up in the computer Alec Boksenberg for these individual photons the computer accepts each photon event, recorded in its memory and now the display shows how the information is accumulating For some applications, photography is still the best way At the Anglo-Australian observatory, research photographer [David Melon.]
has been using a multiple exposure technique to obtain accurate colors Ordinary film is blind incertain Because even with a human telescope, no human eye can see such scene Taking seperate exposures and different color ranges reviews in the arm of this distant spiral the red knots of gases in which stars are forming and the brilliant blue of massive young stars sprinkle among its [swarm.]
of others like our own Sun A kind of [lifelike.]
could possibly live there but that's a rare hint of familiarity in the universe that we still know so little about Even more ordinary photographs may be made to yield new information Using original plates with smooth, centre star mass of the Centaurus galaxy can be mapped out to review detail that's hidden beneath Here they were interested in the rings, its [dust trail.]
that's been circling This is the same galaxy again, Centaurus A But now the space around it contain a ghostly traces of a round, more fainter star With the second technique, this elliptical galaxy can be seemed to be actually larger and with a jet and a reasonably smooth spiral becomes irregular in shape This is a small elliptical galaxy it has a shell that's only recently been noticed a vast array of stars form a wall way out in space No one knows what caused it.
A [ripple.]
from some collision or wave through a gas cloud from which the stars condense These kinds of questions have been investigated by computer, here in the work of MIT Mathematican Alan Turing Galaxies may be masses, but they're actually mostly just space As a few hundred years go by, there's no actual collision But this [titled.]
interaction opens out its spiral arm We've seen this shape before More often, these spirals are angled the Milky Way and Andromeda galaxy might interact like this These two have already happened elsewhere in the heaven Galaxies do collide, what astronomers don't know is the role of such collision in the evolution of galaxies Did spirals collide to form other types? or Do ellipticals slowly develop spirals around them What the history of astronomy has shown over and over again is that the old problems are solved in remarkable and unexpected ways by new technology The photographic plate.
The Spectrograph.
The 100-inch refractor.
Radio Telescope but so far, we aren't running out of problems because the new technology and instrumentation lead us to new phenomena bewildering, scarcely understood One problem recently brought together the resources of stellar institution, new instruments and theoretical work A quasar whose images split in two by gravitational lens was discovered at Jodrell Bank in England Well, it began about 8 years ago, when a group of collegues and I started the survey of radio sources using the [100 metre tall.]
telescope here And we measured actual radio positions so that we could find the [corresponding.]
optical object And many hundreds of these including galaxies and quasars The new quasar appeared as a double image barely resound on the plate from the Palomar Smith Larger telescopes poorly resound them Two distinct images seperated by a 1/600 degree From the quasar on the left, light passes a massive galaxy so close that it's bent And its rays reach us here on Earth by two seperate paths So we see the quasar in two seperate places in the sky The galaxy in the centre act as a gravitational lens a phenomenon predicted by Einstein's General Theory of Relativity From one of the highest observatories on Earth Alan start in Hawaii [.]
obtained a double image that could be processed to remove one quasar revealing the galaxy that split the light the galaxy images faint, it was swarmed by the quasar But now they could see it on its own Just before starting the observation , the team at [.]
also photographed the quasar, using a powerful new detector system This silicon diode array constructs an electronic image that can be displayed directly on a TV screen These were their images This gravity lens established that at least this one quasar had to be very distant But it also provided the means that were driving the mass of the galaxy that bent the light The next technological step for astronomy is to see the galaxies more clearly and to see them deeper in space we're still at the problem of [over.]
atmosphere, that should be a sharp, tiny dot But in the next few years, the space shuttle is scheduled to take an optical telescope with a 54 inch mirror into orbit the stars and the galaxies will be ten times sharper It was an earlier time when that kind of a joke happened, the night when Galileo first started using a telescope himself, just the eyeball and the telescope [Jims Wetsbond.]
First, the simple fact that we see things ten times sharper means that we can examine a galaxy ten times further away it also allows us to see things that are fainter by a factor, may be on the order of 50 But new telescopes are still needed down on the ground However sharp the image, one 54 inch mirror isn't enough for all the questions that remain unresolved This multi-mirror telescope is the first of a new kind with 6 refractors, each the size of Lord Rosse's Leviathan it adds up to the equivalent of 176 inches that's somewhat less than Palomar, but the structure that supports it is smaller in comparison and its cost is correspondingly low this multi-mirror telescope was built just in time for the best early study of the spectrum of the double quasar to show that the two images were really identical On Mount Hopkins in Arizona, this successful new design sent the past toward more to come Verged on its [spinical.]
of 8500 feet The multi-mirror telescope achieved some of the steadiest images in North America essential for cosmoslogical study To see even better image quality astronomers are willing to go the ends of the Earth At nearly 14000 feet, on the rhyme of Maunea Kea in Hawaii is an international collection of telescopes the most powerful or [greatest.]
one has been especially designed to collect the infra-red Here, too, cast is important Its optically excellent 4-meter mirror has been cast unusually thin weighing tons less than usual, its supporting structure was also much cheaper to build And for their purposes, the bright sunny sky doesn't block out their views, they can observe in the daytime as well These efficient new telescopes offer new hopes of further discoveries hopes of new insights into the nature of the universe and our place in it What the history of astronomy had shown over and over again is that the old problems are solved in remarkable and unexpected way by new technology The photographic plate.
The Spectrograph.
The 100-inch refractor.
Radio Telescope But so far, we aren't running out of problems, because the new technology and instrumentation lead us to new phenomena, bewildering scarcely understood From our earliest beginning, we have looked at the stars and wondered some of our oldest [counter.]
facts are the tools we used to try to measure the turning of the sky whether in the company of priests, or scientists or dreamers we are still searching for our place in the heaven