What Is The Most Powerful Thing In The Universe?

there are monsters out there lurking in the

dark for centuries astronomers scanned the heavens again and again without ever

spying them but behind the familiar stars and nearby calm galaxies of our

universe lay something far more vicious far more terrible and far more

powerful completely invisible to the human eye you would never see them even

on the darkest of Knights indeed at first they appeared as nothing but dim

distant pin Pricks of strange radio emission but those pin Pricks revealed

something no astronomer could ever have expected something so strange so bizarre

that for years nobody even believed that they could exist that there must have

been some mistake in our observations thankfully none are nearby

for if they were any closer they would flood us our galaxy our solar system our

planet with deadly radiation a single one of these monsters can easily pump

out over 10 to the power of 40 Jews every second for comparison our sun

outputs about 10 to the power of 34 Jews a million times less every year the

brightest among them outshine Stars outshine galaxies outshine a thousand

galaxies at once some extreme events like the most powerful supern noi can

briefly become brighter than these beacons but those events are temporary

ephemeral flaring and dimming in a matter of weeks when these monsters

awaken they stay powered for millions of years in just a fraction of their

lifetime they can easily produce more energy than even the most intense Cosmic

explosions and they are hungry they feed on anything and are

capable of tearing apart entire stars in a single fit of rage producing flashes

of radiation and jets of charged particles that shoot out from millions

of light years piercing through galaxies and spreading their destruction

throughout entire clusters they are the quazars the most

powerful engines in the known universe but what drives these engines

what powers these lighthouses in the Deep the answer will take us on a

journey through some of the most extreme physics in the universe and even provide

us with a grim warning for though our galaxy is quiet now it will not stay

that way [Music]

forever the most distant quazar from us is 13 billion light years away it would

take nearly the entire history of the universe to travel to and that's without

the universe expanding at the same time space is big and getting bigger and

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at first astronomers had no idea what they were

seeing by the 1950s science had grown used to the idea of galaxies outside the

Milky Way But even in this expanded cosmological view the belief was that

the Universe was relatively small only a few billion light years across at most

and that expanded Cosmos seemed relatively simple even boring there were

galaxies there were were clusters of galaxies there were vast expanses of

nothingness for a Time astronomers were able to convince themselves that they

were finally starting to figure things out but in the mid 20th century there

was a technological Revolution optical telescopes capable of seeing objects inv

visible wavelengths of light were becoming enormous and our ability to use

the rest of the electromagnetic spectrum wavelengths of light outside the visible

grew along with that and with these new observations came the realization that

the Universe was Far weirder than we could have ever

imagined one of the first revolutions was in radio in the 1930s the pioneering

engineer Carl jansky solved the problem of how to reduce noise in sensitive

radio antenna and discovered the first radio signals coming from deep space

among many bright and obvious sources like Jupiter The Crab Nebula and nearby

galaxies astronomers also discovered numerous small faint distant pointlike

radio

objects these strange objects appeared all over the sky emitted radio waves at

a broad range of wavelengths and could not be seen with visible or infrared

telescopes the only clue they gave was their position they appeared both within

the band of the Milky Way and outside of it since our galaxy is a thin d disc

this meant that the sources either had to be extremely close like the visible

stars of the night sky or extremely far away like the distant galaxies but if

they were close we should have been able to see them in Optical wavelengths and

if they were extremely far away their intensity in radio wavelengths implied

they were the brightest objects in the entire universe

understandably many astronomers pushed back against this interpretation not

only arguing about their distance but also openly questioning what could

possibly power something that bright finally a breakthrough came in

1962 by the 1960s astronomers had been able to refine the techniques of radio

astronomy to the point they could more precisely measure the location on the

sky of these strange sources with these new techniques astronomer seral Hazard

and John Bolton found that one radio Source known as 3c273 would undergo

occultations of the Moon allowing them to provide an extremely accurate

estimate of its position following up on that work the Dutch American astronomer

Martin Schmid discovered a faint object in the same location in the visible

spectrum within that visible light Schmidt found the usual collection of

bright spectral lines and dark gaps the Fingerprints of elements and molecules

found throughout the cosmos but these lines were not in their usual

wavelengths instead they were shifted towards the red end of the Spectrum by

nearly 16% to get that kind of red shifting

either 3c273 had to be moving away from us at an incredibly fast speed or it had

to be incredibly far away by this time astronomers had been slowly accepting

The Big Bang Theory of the universe The View that the cosmos was once smaller in

the past and is continuing to grow in the present day under cosmological

expansion light from distant objects red shifts because the space between them

and US expands stretching the light out into longer wavelengths and when he

interpreted the red shifting of the light from 3c273

Schmidt realized it sat 3.4 billion light years away it was the most distant

object by an order of magnitude ever observed

in 1966 Time Magazine put Martin Schmidt on its cover comparing the magnitude of

his Discovery to those of Galileo saying the 17th century Italian startled

scientists and theologians alike the 20th century Dutchman has had an equally

jarring effect on his own

contemporaries 3c273 was a revelation it is so distant

that it appears to us as simply a pointlike object of incredible

luminosity in fact making it another recordbreaker it was also the brightest

known object in astronomy at the time stranger still 3c273 was remarkably

compact now knowing the location of the object astronomers dug back through

archival photographic plates and found that earlier generations of astronomers

had already seen it without recognizing it for what it was year after year 3c273

had shown up but its brightness had varied between annual observations to

change brightness within a year an object must be smaller than a light year

across because any changes to the object can only propagate at a speed lower than

the speed of light So Not only was 3c273 Far brighter and far more distant than

any known object it managed to accomplish both these Feats in a volume

smaller than our solar system with this technique of matching radio sources to

visible light objects in place astronomers went on to confirm the

distances to dozens of these so-called quasi Stell radio sources the name

coming about as early astronomers knew that these objects were not normal stars

but had absolutely no clue what they actually could be it was in 1964 that

the astrophysicist Hong Yi Chu coined its modern cater name in the journal

physics

today so far the clumsily long name quasi Stellar radio sources is used to

describe these objects for convenience the abbreviated form quaza will be used

throughout this paper and so the quazar was

born debate over the true nature of quazars raged for decades within the

astronomical Community many astronomers believe that the original interpretation

was correct that these were incredibly bright incredibly Compact and Incredibly

distant object objects but they could not explain what powered these extreme

objects others continued to argue that these were some sort of exotic star much

closer to our own Galaxy that provided such an extreme amount of gravitational

pull that light escaping from them would red shift making them appear much more

distant than they really were but it wasn't one decisive measurement that

cemented the cosmological nature of quazars but rather a gradual buildup of

observational pressure which grew handin hand with the acceptance of the Big

Bang The Big Bang Theory tells us that the Universe changes with time Not only

was it smaller in the past it was also different quazars only appear in the

extremely distant Universe indeed the nearest quazar sits over 700 million

light years away since astronomy acts like a time machine with more distant

observations revealing the nature of a younger Universe these observations tell

us that quazars were only active in the distant part past and have now gone

quiet this idea fits perfectly with the big bang because we expect the universe

to change as it evolves with time our Dawning understanding of the age and

size of the universe helped paint a portrait of a gigantic ancient Cosmos

that could easily accommodate the distances to even the most far-flung

quaza and so astronomers were left with little choice they had to accept that

these strange intense objects were truly far away and truly bizarrely

[Music]

bright as news of the discovery of quazar worked its way from purely

astronomical circles and into the popular imagination public interest

skyrocketed with writers using the term to elicit a sense of strangeness and

remoteness and if you need a new nursery rhyme to soothe your child you can take

the words of legendary physicist George gof twinkle twinkle quasi star biggest

puzzle from afar how unlike the other ones brighter than a billion Suns

twinkle twinkle quasi star how I wonder what you

are meanwhile astronomers discovered more and more quazars including ones

that were both unusual usually bright and oddly dim the very brightest ones

got a new name blazars While others weren't emitting any radio waves at all

but Were Somehow extremely bright in x-ray radiation and as radio astronomy

became more sophisticated astronomers were able to capture smaller finer

details the most famous example was signus a one of the brightest radio

objects in the entire Sky initially thought to be an exotic Radio Star when

it was first discovered by the 1950s astronomers realized it was far stranger

the central core of signus a was a Galaxy but extending hundreds of

thousands of Li years away from that core with two Thin long Jets ending in

gigantic bubbles screaming in radio emission all of these strange objects

whether loud or quiet in the radio were the relatively nearby or extremely

distant shared one thing in common their cause were abnormally

bright in some cases the nuclei of the galaxies outshone all the hundreds of

billions of stars within the galaxies themselves the brightest of these cores

indicated an enormous amount of activity of Unknown Origin without knowing the

true explanation astronomers conceived of a brand new term to Encompass them

all active Galactic nuclei and so what was going on in the

cores of these galaxies why was some the most luminous objects in the universe

While others were relatively quiet what generated the radio emissions and why

did some blast out x-ray radiation astronomers had discovered a zoo of

active galaxies throughout the cosmos with a dizzying and confusing array of

Galactic creatures something must power them

something must generate the energies needed to make the brightest of them

outshine a thousand galaxies at once something must enable them to be seen

from the the distant reaches of the far Universe these active Galactic nuclei

must have something in common and it was clear that that something lived in their

C and so to understand what drives these the most powerful engines in the known

universe we have to look a little closer to home

25,000 light years away it'ss a monster we wouldn't know it by looking

at it we can't see this monster with our own eyes we can't see it with telescopes

but even decades ago we knew that something strange was there when we look

out at the sky on a dark clear night we can see the band of the Milky Way the

Milky Way is brightest in the direction of the constellation Sagittarius and it

it's there that astronomers discovered the core of our galaxy and when radio

astronomers began their first hesitant explorations of the sky they also found

a bright source of radio emission coming from this point later astronomers

building a catalog of radio sources ranked the brightest object in each

constellation in alphabetical order and so the bright Source in Sagittarius

became known as Sagittarius A still later more Det detailed

observations revealed an exceptionally bright point-like object buried within

the larger Sagittarius a complex because the discovery was exciting and excited

States and atoms get labeled with an asterisk the modern name for the object

at the very center of the Milky Way was born Sagittarius A star it was the same

problem posed by the distant quazars but much closer to home what could possibly