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narrator:tonight on "quest, elephant seals dive deeper,swim farther, and hold their breathlonger than almost any mammal. find out what scientistshave learned about how they accomplishsuch remarkable feats. also, why is the universeexpanding? a mysterious force calleddark energy could be behind it. and for more than 80 years,the hetch hetchy aqueduct has been supplying drinkingwater to bay area residents.

now crews are tryingto rebuild the water system before the next big earthquake. ♪♪ announcer: support for "quest" is provided by... support is also provided by the members of kqed. "quest" is a project of kqed science. narrator: every winter,thousands of very loud, large, visitors stormthe beaches of anã‘o nuevo state reserve --

a jagged stretch of coastline 60 milessouth of san francisco. 50,000 tourists a year trek along sandy dunesand past coastal brush to glimpsethese massive marine mammals during their breeding seasonfrom december through march. woman: over there,you see an alpha bull fighting another guywho wants to be an alpha bull. narrator: elephant seals arethe largest seals in the world.

male northern elephant sealscan be up to 16 feet long and weigh up to 4,500 pounds. brawn trumps brains as the males fightfor the much smaller females who congregate in harems dotting anã‘o nuevo, which was namedfor the new year's day in 1603 when it was first spotted by spanish explorersebastian vizcaino.

nearly 5,000 elephant seals congregate at anã‘o nuevo statereserve during the breeding season. it's a testamentto their astounding comeback from near extinction100 years ago. le boeuf: the animals wereexploited for their blubber, which was reducedto a very fine oil. narrator: by the 1890s, only about 30 elephant sealssurvived,

confined to isla de guadalupe, a volcanic island off the coastof baja california. in 1922, scientistsfrom the california academy of sciences made a surveyof rare animals on the island. they found a small herdof elephant seals. a few months later, the mexican government declaredthe island a protected reserve. le boeuf: all of the 170,000elephant seals that exist today

trace their lineageto the 30 individuals that survivedon isla de guadalupe. narrator: today, the populationof northern elephant seals is robust, with breeding coloniesscattered from point reyes national seashoreto baja california. and for male elephant seals, mating is a high-stakes gamewith few winners and lots of losers.

le boeuf: one male may monopolize mating,in an ideal situation, with up to 100 females. [ seal trumpets ] narrator: with their nosesinflating with air, the males trumpet their battle call. these fights to gain access tobreeding females can be brutal. but as scientists at u.c.santa cruz discovered, the encountersallow male elephant seals

to learn the distinctive callsof males they fought with before. if a male won an earlier fight, it will move toward the soundof the losing seal, ready to take it on. if it lost, it will scamperaway, avoiding another fight. "athletic" may not be a wordthat springs to mind when describingthese blubbery beach visitors. and yet they can diveand swim past much

of the marine competition. costa: elephant sealsare really animal olympians. when it comes to diving,the only other group of marine mammals that even comeclose to them is the sperm whale and beaked whales. they're diving routinely between1,500 and 2,000 feet of water. and occasionally, they'll divefor almost two hours. narrator: elephant sealsalso travel twice a year, up to 12,000 miles,

to forage for foodsuch as fish and squid. so, studying themwhen they're underwater for most of their livesrequires high-tech tools. costa: if you goto this textbook from 1990 on pinnipeds, here's where we thoughtthe distribution was of elephant seals. up from vancouver island up here, down to the middleof baja california,

and then a few hundred miles off the coast. once we put a satellite tagon the animals, we found that elephant seals were using virtually the wholenortheastern pacific ocean. we had no ideathis is what they were doing, because the animalsare under water and you just don't see them. narrator: today,this seal surveillance

has met the digital age. since 2000, dan costa and his studentsat the university of california, santa cruz have taggedmore than 500 elephant seals. costa:i'm involved in a project called the taggingof pacific predators, and it's a projectwhich takes the approach that we've hadwith elephant seals, but magnifies that to look

at how the northeastern pacificocean is used by different speciesof marine animals -- not just marine mammals, but marine birds, sharks, fishes, and turtles. narrator: the tagging is revealinghow critical certain regions of the ocean are,

not only for elephant seals but also for the survivalof their marine neighbors. costa: there's a groupof animals -- elephant seals,northern fur seals, salmon sharks, and albatrosses -- all feed in this region of the northpacific transition zone. it's this regionbetween the colder and warmer watersof the north pacific.

so this is colder water here,warmer water, hawaiian islands, and all these little squigglesor worms are northern elephant seals. and you can see that they reallylike this area on the sort of cold water sideof this big system. and we call these fronts, just like we havea weather front coming in in the atmosphere. narrator: noneof this groundbreaking research

would have been possiblewithout innovative tags which keep gettingsmaller and smarter. costa: this tag justmeasures time and depth. this tag justgives us animal location, so it transmitsto argos satellites overhead. this tag tells uswhere the animal is, what it's doing, and gives usmuch higher quality locations. i have to hold these two thingstogether.

this does it all. we can dial upthrough the internet, and find out where the animal was when those datawere transmitted. satellite tags are giving usa much deeper, richer understandingof where these animals go, and where they livedand where they spend their time. today, dan costa's studentsprepare for the returning seals, and the clues theycarry about their lives at sea.

teutschel: we'reat anã‘o nuevo state reserve in northern california today, and we're hereto recover satellite tags from an adult femalenorthern elephant seal. so on a typical day where we'reretrieving a satellite tag, we locate the femalethat we've been watching. and as we sneakby all the seals, we're getting ready to givean initial injection of a mild tranquilizer,

basically to makethe seal fall asleep so we can safelyretrieve the tags. man: 46-x. teutschel: and then wecheck the health of the animal. and looking at her, she'sprobably about 500 kilograms, so she's quite a largenorthern female elephant seal. -man: she's off.-teutschel: someone read it. -man: 5-4-7.-teutschel: 5-4-7. we start taking measurements,like blubber thickness,

blood samples, and we also take whiskers. [ groans ] man: back. narrator: this essential fieldwork is also a reminder of the cycle of life and losswhich marks the breeding season. teutschel: she did not havea pup with her. she has given birth, and we have observed herfor multiple days with a pup.

but sometimes in the crazinessof the harem, the male fights and things, they lose their pup. [ seals barking ] narrator:high-tech tracking toolsand old-fashioned field work are helping liftthe ocean's dark veil to reveal the secretsof the seals. but some secrets remain. costa: if you have a female that goes outto the international dateline

and turn aroundand come back like a beeline and finds anã‘o nuevo reserve,how does she do that? how do they dive for two hours? what's the metabolism? how do they change their abilityto store oxygen? how do these animalstake the pressure? it always amazes me that, after all these many yearsof studying these animals, that there's stillso much more to learn.

it's what drives me. it's what drives a lotof us that do this. narrator: let me tell youa bedtime story -- a different kindof bedtime story. perlmutter: it begins, we think,almost 14 billion years ago with a very hot,dense beginning, and we call it the big bang. and it expanded manyfold,all of a sudden, very fast. narrator: but then,

something happened. perlmutter: that rapidaccelerating expansion stopped. and it just started to coast. and in fact it continuedto expand and expand and expand vastly, but slower and slower andslower for some 7 billion years. narrator: and then,things shifted again. perlmutter: around 7 billionyears ago, we believe that something startedto speed up the universe.

narrator: and this iswhere we are right now, living in a universe that is accelerating,expanding faster and faster. now, if you're oneof those people who are just now discoveringthat the universe is expanding, let alone accelerating,don't feel bad. even einstein,in his theory of gravity, assumed that the universewas static. perlmutter: if somebodyhadn't told you

that the universe was expanding, it would justseem pretty unlikely, right? i mean, if, you know,if you just sat and thought what kindof universe could we live in, the first thingthat would come to your mind would not be a universethat was actually getting bigger and bigger. i think you're only drivento that when you actually see the data.

narrator:above the u.c. berkeley campus at the berkeley lab, physicist saul perlmutteris one of the researchers who have actually seenthat data. for nearly 20 years, he's helped reshapeour understanding of the cosmos. some forceswe are familiar with. wind makes the cloudsdrift along. the moon helps drivethe oceans' tides.

and something is causing the galaxiesto rush away from each other. researchers believethe something that is pushing the universeapart makes up 70% of the fabric of the universe. but they're literallyin the dark about what this something is, and so they've takento calling it "dark energy." fakhouri: it's very exotic,it's very strange.

and the strangest part, right,is that it's 70% of reality. 70% of the stuff in the universe is this thing that we justdo not understand at all. narrator: if you're startingto get a little uneasy about the fact that two thirds of the universeis unknown, rest assured, scientists out there are lookingfor answers. perlmutter: and i thinki was just one of those kids who always thoughtthat we should know

how the world works around us, that here we live on this earth and we don't fallthrough the floor, and somebody should havegiven us an owner's manual about how the whole thingfits together and how you use it. narrator: in 2011, perlmuttershared the nobel prize for discovering thatthe expansion of the universe started to accelerate7 billion years ago.

but what exactly does it meanthat the expansion is accelerating? first, you have to understandthe universe is infinite. perlmutter: just imagine thatyou are living here on a galaxy, and there's galaxiesforever going that way and there are galaxiesforever going that way in all directions, nothing but galaxies, no end. and just imagine that there'ssort of a typical distance

between those galaxies, and the only thingi mean when i'm saying that the universeis expanding is that we're sort of pumping extra spacebetween the galaxies. and when we sayit's accelerating, we just mean that that extra pumpingis happening faster and faster and the distances are growing bigger and biggermore and more quickly. narrator: so,how did perlmutter's team figure

out the history of the universe? they did so by lookingat the light from supernovae -- stars that exploded billions of years ago. -swift: hey.-perlmutter: how's it looking? swift: it's looking good. the weather's good. the telescope has been released,and we're... narrator: sitting in a roomat the berkeley lab,

perlmutter and physicsstudent hannah swift are connected to one ofthe world's largest telescopes, the keck 2, in hawaii. the other half of their teamis actually in hawaii. man: what? swift: i said we're curiousas to what's for dinner. man: you know that chineseplace? perlmutter: [ chuckles ] what do the odds look likefor tonight for the weather?

man: i think it looks good. i think we're definitelygoing to get data. narrator: their planfor the night is to confirm that five supernovae previously identifiedthrough another telescope are the type 1a supernovaethey need for their research. perlmutter: the type 1asupernovae explode in a very similar wayevery time, and so they brighten likefireworks and then fade away,

but they reachthe same peak brightness. narrator: their predictabilitymakes these exploding stars what researcherscall standard candles. their initial brightnessis constant and it grows fainterwith distance. and since researchers know light always travelsat 186,000 miles per second, they're able to calculatehow long ago these supernovae exploded.

perlmutter: when a supernovaexplodes, the light starts spreading outin all directions, much like the rippleson the water spread out when youdrop a pebble into the lake. narrator: the supernovae perlmutter studied explodedbillions of years ago. so, as the lightfrom the explosion was travelingtowards our galaxy, our solar systemhad time to develop,

dinosaurs had a chanceto come and go, and we humansmade our grand entrance and had timeto build our telescopes. as the star moves away from us, one other thinghappens to its light. because the universeis expanding, the light waves stretch. perlmutter: while the lightis traveling to us through the universe,

the universe is expanding. and everything in the universe that's not nailed down expandswith the universe. and that includesthe very wavelengths of the photons of light that are traveling to usfrom the supernova. narrator: if the object ismoving away from the observer, it will appear red. in astronomy, this phenomenonis known as redshift.

one way to visualizethese stretching wavelengths is to lookat how waves of sound, which are similarto waves of light, change. [ car horn changing pitch ] can you hear how the pitchof the honk changed as the sound sourcemoved away from you? this is because its wavelengthis stretching. the same happenswith supernovae's light. perlmutter: now,with these two ingredients --

the brightness of the supernova and how much the light has been shifted towards the redin its appearance -- you now can just read off the history of the expansionof the universe, because the brightness tells you how far back in time any givensupernova event occurred. the redshift, as we call it, tells us how much the universehas expanded since that time.

and now we just do this for 5,10, 20, 40 supernovae at different timesback in history and they, one after another,tell us for each time in history how much the universehas stretched since that time. man: i thinki'll start another exposure when this is completeand see what it looks like, and then i'll abort it, well, depending on what it looks like. swift: okay.

narrator:but even though astronomers have become the historiansof the universe, they can only speculate aboutwhat's causing this stretching. perlmutter: one example of aslightly more exotic explanation could be that there'sextra dimensions in the universe beyond the three dimensionsthat we're aware of, of space and the one dimensionof time. it's possiblethat there are other dimensions that we justdon't usually experience.

perhaps in some way, we're limited to the dimensionsthat we experience, but that other things,like perhaps gravity, could not be limited, and maybe it can seep into oneof these extra dimensions. and that would makeit look to us as if it was becoming diluted, that you're havingless effective gravity and perhaps that's one

of the reasons the universecould be accelerating. narrator: or the acceleratedexpansion could actually be caused byan entirely new form of energy. so long as dark energycontinues to be a mystery, it's unclear what the futureof the universe might be. for now, perlmutter is enjoyinghis privileged vantage point. perlmutter: in some sense, we may have foundjust the right spot to come to, so we're at just the right scale

to be able to enjoy looking outat the infinite space above us, and down into the microscopicworld beneath us. we're, i think, at justabout the right time in history to be able to look backat the early, hot, fiery big bang period, and project into the futureof what we might get to see. in some sense,we're in a very cozy medium, and i think it's a nice placeto be. man: okay.

narrator: less than a mile frommission boulevard in fremont, engineers with the san franciscopublic utilities commission are descending deep undergroundto inspect the progress on a new tunnel. wade: we'll have to tie in thispiece right here in the shaft first, weld it into place, backfill concrete it. narrator: this nine-footdiameter tunnel is now open, carrying on average 62,000gallons of water

a minute each dayto four bay area counties. it's a key step in upgradingand replacing parts of a system that has served the bay areafor 80 years. wade: we're hereat the new irvington tunnel. this is one of the mostcritical pieces of our system because when we're done and weput this tunnel into service, it's going to carry waterthat serves 2.6 million peoplein the bay area. narrator: dan wadeis the director

of the hetch hetchy watersystem improvement program. at a costof nearly $5 billion dollars, it's one ofthe largest engineering projects in the nation. wade: the new irvington tunnelis steel-lined, and ithas a concrete reinforcement, and that ensures that we have a reliableearthquake-resistant tunnel well into the future.

narrator: the san franciscopublic utilities commission is in chargeof making sure the taps keep flowing with this water. it originates 167 milesaway at hetch hetchy reservoir in yosemite. but much of the system was builtin the 1920s and '30s. today, a major earthquake could leave parts of the bayarea without water for a month. wade: one of the primary goalsof the water system improvement

program is to ensurethat within 24 hours after a major earthquake, we will be able to deliver waterto the customers. narrator: and to pay for it, water rates have beengoing up -- way up -- for the system's customers who live in san francisco,san mateo, alameda, and santa clara counties. wade: one third of the customerslive in san francisco,

and so they're goingto pay one third of the bill, and the other two thirdswill be paid by our customers outside of san francisco. san francisco residentswill see their water rates approximately triple by the timethe program is done. narrator: the voter-approvedprogram began in 2004 and is scheduled to end in 2018. but there's urgencyto get it done. wade: we have the calaverasfault,

the hayward faultin the east bay, and then of course, the sanandreas fault on the peninsula. and our water system crossesall three of those major faults. the u.s. geological survey,a few years ago, predicted that by 2035, there's more than a 63% chance that there'd be a majorearthquake here in the bay area. so we're truly in a raceagainst time. man:[ speaks indistinctly ]

narrator:the work is on track, and occasionally,even ahead of schedule. wade: one of our most impressiveprojects is the new bay tunnel, a five-mile pipeline underneaththe san francisco bay, and it's the first true tunnel that's been constructedunderneath the bay. narrator: to helpshield it from the shaking during an earthquake, the team built this new tunnel

in a bed of thick clay 100 feetbeneath san francisco bay. it replaces two pipelinesbuilt in 1925 and 1936, and carries waterfrom the east bay to san franciscoand the peninsula. wade: the hetchhetchy water system has been serving us very wellthroughout the 20th century and into the 21st. however, the infrastructureis old. it's aging, it's in needof repair or replacement

or upgrades. narrator: with mostof the roughly 80 upgrades and replacements done, the construction crewsare hard at work on the toughestand biggest project of them all. wade: calaveras dam was builtin 1925. it forms calaveras reservoir, which isthe largest local reservoir that's part of our system.

we needed to permanentlyrestrict the reservoir level to about 40% of capacity. narrator:this new dam is being built near the alameda-santa claracounty line out of earth and rock,like the old dam. the new dam, however, will be seismically stronger, which will allowthe calaveras reservoir to fill to capacity --

31 billion gallons. wade: california isin a severe drought. we need this reservoirfor drought carryover storage. the program has a goal of meeting a drought periodof seven and a half years to ensure that we can continueto supply water to our customers in that length of drought. narrator: as bulldozersexcavate dirt and rock to carve outthe 220-foot-tall dam,

long-buried treasures fromthe bay area's prehistoric past are coming to light. walker: every day i come outhere, i'm very excited. i get to look for fossils from creaturesthat lived 20 million years ago. today, we found two vertebraefrom a whale. probably between the size of a large dolphinand a killer whale. in the past,we've found sharks' teeth.

this is the toothof a megalodon. it's a prehistoric shark that lived about 20 millionyears ago. this individual,based on the tooth size, would have beenabout 25 to 30 feet long. to date,we have over 650 fossils. narrator: nearby, the crewsscour the valley's walls to make room for the newwatertight foundation. but a reminder will still standof what was once

the world's largestearth and rock dam. wade: when this new damis complete in 2018, we'll actually cut a notchand remove about one third of the existing dam so that the reservoir can come up against the faceof the new dam. narrator:dan wade and his team are more than halfwaydone replacing the dam, a critical step in protectinghetch hetchy's water

from a big quake that could strike at any moment. wade: water is a preciousresource. we cannot live without it. we're doing something that'sgoing to have a lasting effect, to ensure the long-term healthand safety, and economic viabilityof the san francisco bay area. male announcer: a kqed television production.