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  • All across the immense reaches of time and space, energy is being exchanged, transferred,

  • released, in a great cosmic pinball game we call our universe.

  • How does energy stitch the cosmos together, and how do we fit within it? We now climb

  • the power scales of the universe, from atoms, nearly frozen to stillness, to Earth’s largest

  • explosions.

  • From stars, colliding, exploding, to distant realms so strange and violent they challenge

  • our imaginations.

  • Where will we find the most powerful objects in the universe?

  • Today, energy is very much on our minds as we search for ways to power our civilization

  • and serve the needs of our citizens.

  • But what is energy? Where does it come from? And where do we stand within the great power

  • streams that shape time and space?

  • Energy comes from a Greek word for activity or working. In physics, it’s simply the

  • property or the state of anything in our universe that allows it to do work.

  • Whether it’s thermal, kinetic, electro-magnetic, chemical, or gravitational.

  • The 19th century German scientist Hermann von Helmholtz found that all forms of energy

  • are equivalent, that one form can be transformed into any other.

  • The laws of physics say that in a closed system - such as our universe - energy is conserved.

  • It may be converted, concentrated, or dissipated, but it’s never lost.

  • James Prescott Joule built an apparatus that demonstrated this principle. It had a weight

  • that descended into water and caused a paddle to rotate. He showed that the gravitational

  • energy lost by the weight is equivalent to heat gained by the water from friction with

  • the paddle.

  • That led to one of several basic energy yardsticks, called a joule. It’s the amount needed to

  • lift an apple weighing 100 grams one meter against the pull of Earth’s gravity.

  • In case you were wondering, it takes about one hundred joules to send a tweet, so tweeted

  • a tech from Twitter.

  • The metabolism of an average sized person, going about their day, generates about 100

  • joules a second, or 100 watts, the equivalent of a 100-watt light bulb.

  • In vigorous exercise, the power output of the body goes up by a factor of ten, one order

  • of magnitude, to around a thousand joules per second, or a thousand watts.

  • In a series of leaps, by additional factors of ten, we can explore the full energy spectrum

  • of the universe.

  • So far, the coldest place observed in nature is the Boomerang Nebula. Here, a dying star

  • ejected its outer layers into space at 600,000 kilometers per hour.

  • As the expanding clouds of gas became more diffuse, they cooled so dramatically that

  • their molecules fell to just one degree above Absolute Zero, one degree above the total

  • absence of heat.

  • That’s around a billion trillionths of a joule, give or take.

  • That makes the signal sent by the Galileo spacecraft, as it flew around Jupiter, seem

  • positively hot. By the time it reached Earth, its radio signal was down to 10 billion billionths

  • of a watt.

  • Now jump all the way to 150 billionths of a watt.

  • That’s the amount of power entering the human eye from a pair of 50-watt car headlamps

  • a kilometer away.

  • Moving up a full seven powers of ten, moonlight striking a human face adds up to three hundred

  • thousandths of a watt. That’s roughly equivalent to a cricket’s chirp.

  • From there, it’s a mere five powers of ten to the low wattage world of everyday human

  • technologies.

  • Put ten 100-watt bulbs together. At 1000 joules per second, 1000 watts, that roughly equals

  • the energy of sunlight striking a square meter of Earth’s surface at noon on a clear day.

  • Gather 200 bulbs, 20,000 watts is the energy output of an automobile.

  • A diesel locomotive: 5 million watts.

  • An advanced jet fighter: 75 million watts.

  • An aircraft carrier, almost two hundred million watts.

  • The most powerful human technologies today function in the range of a billion to 10 billion

  • watts, including large hydro-electric or nuclear power plants.

  • At the upper end of human technologies, was the awesome first stage of a Saturn V rocket.

  • In five separate engines, it consumed 15 tons of fuel per second to generate 190 billion

  • watts of power.

  • How much power can humanity marshal? And how much do we need?

  • Long before the launch of the space age, visionaries began to imagine what it would take to advance

  • into the community of galactic civilizations.

  • In the 1960s, the Soviet scientist, Nicolai Kardashev, speculated that a Level 1 civilization

  • would acquire the technology needed to harness all the power available on a planet like Earth.

  • According to one calculation, we are .16% of the way there. This is based on British

  • Petroleum’s estimate of total world oil consumption, some 11 billion tons in 2007.

  • Humans today generate about two and a half trillion watts of electrical power. How does

  • that stack up to the power generated by planet Earth?

  • Deep inside our planet, the radioactive decay of elements such as uranium and thorium generates

  • 44 trillion watts of power.

  • As this heat rises to the surface, it drives the movement of Earth’s crustal plates and

  • powers volcanoes.

  • Remarkably, that’s just a fraction of the energy released by a large hurricane in the

  • form of rain. At the storm’s peak, it can rise to 600 trillion watts.

  • A hurricane draws upon solar heat collected in tropical oceans in the summer.

  • You have to jump another power of ten to reach the estimated total heat flowing through Earth’s

  • atmosphere and oceans from the equator to the poles

  • And another two to get the power received by the Earth from the sun at 174 quadrillion

  • watts.

  • Believe it or not, there’s one human technology that has exceeded this level.

  • The AN602 hydrogen bomb was detonated by the Soviet Union on October 30, 1961.

  • It unleashed some 1400 times the combined power of the Nagasaki and Hiroshima bombs.

  • With a blast yield of up to 57,000,000 tons of TNT, it generated 5.3 trillion trillion

  • watts, if only for a tiny fraction of a second.

  • That’s 5.3 Yotta-watts, a term that will come in handy as we now begin to ascend the

  • power scales of the universe.

  • To Nikolai Kardashev, a Level 2 civilization would achieve a constant energy output 80

  • times higher than the Russian superbomb.

  • That’s equivalent to the total luminosity of our sun, a medium-sized star that emits

  • 375 yotta-watts.

  • However, in the grand scheme of things, our sun is but a cold spark in a hot universe.

  • Look up into Southern skies and youll see the Large Magellanic Cloud, a satellite galaxy

  • of our Milky Way. Deep within is the brightest star yet discovered.

  • R136a1 is 10 million times brighter than the sun.

  • Now if that star happened to go supernova, at its peak, it would blast out photons with

  • a luminosity of around 500 billion yottawatts.

  • To advance to a level three civilization, you have to marshal the power of an entire

  • galaxy.

  • The Milky Way, with about two hundred billion stars, has an estimated total luminosity of

  • 3 trillion yotta-watts, a three followed by 36 zeros.

  • The author Isaac Asimov imagined a galaxy-scale civilization in his Foundation series.

  • Galaxia, he called it, is a super-organism that surpasses time and space to draw upon

  • all the matter and energy in a galaxy.

  • But who’s to say that’s the upper limit for civilizations?

  • To boldly go beyond Level 3, a civilization would need to marshal the power of a quasar.

  • A quasar is about a thousand times brighter than our galaxy.

  • Here is where cosmic power production enters a whole new realm, based on the physics of

  • extreme gravity.

  • It was Isaac Newton who first defined gravity, as the force that pulls the apple down and

  • holds the earth in orbit around the sun.

  • Albert Einstein re-defined it in his famous General Theory of Relativity.

  • Gravity isn’t simply the attraction of objects like stars and planets, he said, but a distortion

  • of space and time, what he called space-time.

  • If space-time is like a fabric, he said, gravity is the warping of this fabric by a massive

  • object like a star.

  • A planet orbits a star when it’s caught in this warped space like a ball spinning

  • around a roulette wheel.

  • Some scientists began to wonder: if matter became dense enough, could it warp space to

  • such an extreme that nothing could escape its gravity, not even light?

  • With so much power being emitted from such a small area, scientists suspected that quasars

  • were actually being powered by black holes.

  • How a totally dark object can do this has been narrowed by decades of observations and

  • theory.

  • If a black hole spins, it can turn into a violent, cosmic tornado.

  • Gas and stars begin to flow in along a rapidly rotating disk. The spinning motion of this

  • so-calledaccretion diskgenerates magnetic fields that twist up and around.

  • These fields can channel some of the inflowing matter out into a pair of high-energy beams,

  • or jets.

  • Gas and dust nearby catch the brunt of this energy, growing hot and bright enough to be

  • seen billions of light years away.

  • Amazingly, the power of a black hole can rise to even greater extremes at the moment of

  • its birth.

  • As a giant star ages, heavy elements like iron gradually build up in its core.

  • As its gravity grows more intense, the star begins to shrink, until it reaches a critical

  • threshold.

  • Its core literally collapses in on itself.

  • That causes the star to explode in a supernova. And now, in death, the star can unleash gravity’s

  • true fury.

  • In the violence of the star’s death, gravity can cause its massive core to collapse to

  • a point, forming a black hole.

  • In some rare cases, the new-born monster powers a jet that accelerates to within a tiny fraction

  • of the speed of light.

  • For a few minutes, these so-calledgamma ray burstsare known to be the brightest

  • events since the big bang

  • Three orders of magnitude above a quasar, at a billion billion yotta-watts, a ten with

  • 42 zeros.

  • Remarkably, they are still not the most powerful events known.

  • Albert Einstein‘s equations contained an astonishing prediction: that when massive

  • bodies accelerate or whip around each other, they can stir up the normally smooth fabric

  • of space-time.

  • They produce a series of waves that move outward like ripples on a pond.

  • Scientists are now hoping to detect these gravitational waves, and verify Einstein’s

  • predictionusing precision lasers and some of the most perfect large-scale vacuums ever

  • created.

  • At the Laser Interferometry Gravitational Wave Observatory, known as LIGO, they are

  • hoping to record

  • The collision of ultra-dense remnants of dead stars known as neutron stars and of black

  • holes.

  • According to computer simulations, as two black holes spiral into a fateful embrace,

  • the energy carried by each gravity wave rises five orders of magnitude above a gamma ray

  • burst, to a hundred billion trillion times the power of our sun.

  • Does the collision of black holes define the known power limits of our universe?

  • Perhaps not.

  • As turbulent as the environment of a black hole might be, its true power may well lie