[O]ne might ask why, in a galaxy of a few hundred billion stars, the aliens are so intent on coming to Earth at all. It would be as if every vertebrate in North America somehow felt drawn to a particular house in Peoria, Illinois. Are we really that interesting?

[W]e might expect intelligent life and technological communities to have emerged in the universe billions of years ago. Given that human society is only a few thousand years old, and that human technological society is mere centuries old, the nature of a community with millions or even billions of years of technological and social progress cannot even be imagined. ... What would we make of a billion-year-old technological community?

Ode to The Amoeba
Recall from Time's abysmal chasm
That piece of primal protoplasm
The First Amoeba, strangely splendid,
From whom we're all of us descended.
That First Amoeba, weirdly clever,
Exists today and shall forever,
Because he reproduced by fission;
He split himself, and each division
And subdivision deemed it fitting
To keep on splitting, splitting, splitting;
So, whatsoe'er their billions be,
All, all amoebas still are he.
Zoologists discern his features
In every sort of breathing creatures,
Since all of every living species,
No matter how their breed increases
Or how their ranks have been recruited,
From him alone were evoluted.
King Solomon, the Queen of Sheba
And Hoover sprang from that amoeba;
Columbus, Shakespeare, Darwin, Shelley
Derived from that same bit of jelly.
So famed is he and well-connected,
His statue ought to be erected,
For you and I and William Beebe
Are undeniably amoebae!

A great ball of fire about a mile in diameter, changing colors as it kept shooting upward, from deep purple to orange, expanding, growing bigger, rising as it was expanding, an elemental force freed from its bonds after being chained for billions of years.
On the first atomic explosion in New Mexico, 16 Jul 1945.

A hundred years ago, there were one-and-a-half billion people on Earth. Now, over six billion crowd our fragile planet. But even so, there are still places barely touched by humanity.

A million million spermatozoa,
All of them alive:
Out of their cataclysm but one poor Noah
Dare hope to survive.
And among that billion minus one
Might have chanced to be Shakespeare, another Newton, a new Donne—
But the One was Me.

A star is drawing on some vast reservoir of energy by means unknown to us. This reservoir can scarcely be other than the subatomic energy which, it is known exists abundantly in all matter; we sometimes dream that man will one day learn how to release it and use it for his service. The store is well nigh inexhaustible, if only it could be tapped. There is sufficient in the Sun to maintain its output of heat for 15 billion years.

After that cancellation [of the Superconducting Super Collider in Texas, after $2 billion had been spent on it], we physicists learned that we have to sing for our supper. ... The Cold War is over. You can't simply say “Russia!” to Congress, and they whip out their checkbook and say, “How much?” We have to tell the people why this atom-smasher is going to benefit their lives.

Ah, the architecture of this world. Amoebas may not have backbones, brains, automobiles, plastic, television, Valium or any other of the blessings of a technologically advanced civilization; but their architecture is two billion years ahead of its time.

An example of such emergent phenomena is the origin of life from non-living chemical compounds in the oldest, lifeless oceans of the earth. Here, aided by the radiation energy received from the sun, countless chemical materials were synthesized and accumulated in such a way that they constituted, as it were, a primeval “soup.” In this primeval soup, by infinite variations of lifeless growth and decay of substances during some billions of years, the way of life was ultimately reached, with its metabolism characterized by selective assimilation and dissimilation as end stations of a sluiced and canalized flow of free chemical energy.

An unelectrified atom is so elusive that unless more than a million million are present we have no means sufficiently sensitive to detect them, or, to put it another way, unless we had a better test for a man than for an unelectrified molecule, we should be unable to find out that the earth was inhabited. … A billion unelectrified atoms may escape our observation, whereas a dozen or so electrified ones are detected without difficulty.

And beyond our galaxy are other galaxies, in the universe all told at least a hundred billion, each containing a hundred billion stars. Do these figures mean anything to you?

Any living cell carries with it the experience of a billion years of experimentation by its ancestors. (1949)

Anyone informed that the universe is expanding and contracting in pulsations of eighty billion years has a right to ask. What's in it for me?

At the planet’s very heart lies a solid rocky core, at least five times larger than Earth, seething with the appalling heat generated by the inexorable contraction of the stupendous mass of material pressing down to its centre. For more than four billion years Jupiter’s immense gravitational power has been squeezing the planet slowly, relentlessly, steadily, converting gravitational energy into heat, raising the temperature of that rocky core to thirty thousand degrees, spawning the heat flow that warms the planet from within. That hot, rocky core is the original protoplanet seed from the solar system’s primeval time, the nucleus around which those awesome layers of hydrogen and helium and ammonia, methane, sulphur compounds and water have wrapped themselves.

Each nerve cell receives connections from other nerve cells at six sites called synapses. But here is an astonishing fact—there are about one million billion connections in the cortical sheet. If you were to count them, one connection (or synapse) per second, you would finish counting some thirty-two million years after you began. Another way of getting a feeling for the numbers of connections in this extraordinary structure is to consider that a large match-head’s worth of your brain contains about a billion connections. Notice that I only mention counting connections. If we consider how connections might be variously combined, the number would be hyperastronomical—on the order of ten followed by millions of zeros. (There are about ten followed by eighty zero’s worth of positively charged particles in the whole known universe!)

Ecologically speaking, a spilt tanker load is like sticking a safety pin into an elephant’s foot. The planet barely notices. After the Exxon Valdez accident in Alaska the oil company spent billions tidying up the coastline, but it was a waste of money because the waves were cleaning up faster than Exxon could. Environmentalists can never accept the planet’s ability to self-heal.

Energy of the tides is continuously being dissipated at a rate whose order of magnitude is a billion horsepower!

Enthusiasm for the global-warming scare also ensures that heatwaves make headlines, while contrary symptoms, such as this winter’s billion-dollar loss of Californian crops to unusual frost, are relegated to the business pages. The early arrival of migrant birds in spring provides colourful evidence for a recent warming of the northern lands. But did anyone tell you that in east Antarctica the Adélie penguins and Cape petrels are turning up at their spring nesting sites around nine days later than they did 50 years ago? While sea-ice has diminished in the Arctic since 1978, it has grown by 8% in the Southern Ocean.

Even if only one in a hundred of the ten billion suitable planets has actually got life well under way, there would be more than 100 million such planets. No, it is presumptuous to think that we are alone.

Every creature alive on the earth today represents an unbroken line of life that stretches back to the first primitive organism to appear on this planet; and that is about three billion years.

Finally, from what we now know about the cosmos, to think that all this was created for just one species among the tens of millions of species who live on one planet circling one of a couple of hundred billion stars that are located in one galaxy among hundreds of billions of galaxies, all of which are in one universe among perhaps an infinite number of universes all nestled within a grand cosmic multiverse, is provincially insular and anthropocentrically blinkered. Which is more likely? That the universe was designed just for us, or that we see the universe as having been designed just for us?

For a billion years the patient earth amassed documents and inscribed them with signs and pictures which lay unnoticed and unused. Today, at last, they are waking up, because man has come to rouse them. Stones have begun to speak, because an ear is there to hear them. Layers become history and, released from the enchanted sleep of eternity, life’s motley, never-ending dance rises out of the black depths of the past into the light of the present.

Forests … are in fact the world’s air-conditioning system—the very lungs of the planet—and help to store the largest body of freshwater on the planet … essential to produce food for our planet’s growing population. The rainforests of the world also provide the livelihoods of more than a billion of the poorest people on this Earth… In simple terms, the rainforests, which encircle the world, are our very life-support system—and we are on the verge of switching it off.

Gaia is a thin spherical shell of matter that surrounds the incandescent interior; it begins where the crustal rocks meet the magma of the Earth’s hot interior, about 100 miles below the surface, and proceeds another 100 miles outwards through the ocean and air to the even hotter thermosphere at the edge of space. It includes the biosphere and is a dynamic physiological system that has kept our planet fit for life for over three billion years. I call Gaia a physiological system because it appears to have the unconscious goal of regulating the climate and the chemistry at a comfortable state for life. Its goals are not set points but adjustable for whatever is the current environment and adaptable to whatever forms of life it carries.

Herschel removed the speckled tent-roof from the world and exposed the immeasurable deeps of space, dim-flecked with fleets of colossal suns sailing their billion-leagued remoteness.

Hidden within the vast spaces of the Milky Way are over a billion targets for the search for intelligent life. … A decision has to be made as to which stars should be the first objects of this search, … [But] only stars not much different from the sun are likely to support intelligent creatures. So the search should concentrate on … the nearest of these stars first, since the inverse square law indicates that signals from the closest stars would be the strongest received on the earth.

However improbable we regard [the spontaneous origin of life],… it will almost certainly happen at least once…. The time… is of the order of two billion years.… Given so much time, the “impossible” becomes possible, the possible probable, and the probable virtually certain. One only has to wait: time itself performs the miracles.

Humans everywhere share the same goals when the context is large enough. And the study of the Cosmos provides the largest possible context … . If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another … . If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth.

I am a creationist and an evolutionist. Evolution is God's, or Nature's method of creation. Creation is not an event that happened in 4004 BC; it is a process that began some 10 billion years ago and is still under way.

I am not insensible to natural beauty, but my emotional joys center on the improbable yet sometimes wondrous works of that tiny and accidental evolutionary twig called Homo sapiens. And I find, among these works, nothing more noble than the history of our struggle to understand nature—a majestic entity of such vast spatial and temporal scope that she cannot care much for a little mammalian afterthought with a curious evolutionary invention, even if that invention has, for the first time in so me four billion years of life on earth, produced recursion as a creature reflects back upon its own production and evolution. Thus, I love nature primarily for the puzzles and intellectual delights that she offers to the first organ capable of such curious contemplation.

I believe that life can go on forever. It takes a million years to evolve a new species, ten million for a new genus, one hundred million for a class, a billion for a phylum—and that’s usually as far as your imagination goes. In a billion years, it seems, intelligent life might be as different from humans as humans are from insects. But what would happen in another ten billion years? It’s utterly impossible to conceive of ourselves changing as drastically as that, over and over again. All you can say is, on that kind of time scale the material form that life would take is completely open. To change from a human being to a cloud may seem a big order, but it’s the kind of change you’d expect over billions of years.

I now think the answer is very simple: it’s true. God did create the universe about 13.7 billion years ago, and of necessity has involved Himself with His creation ever since. The purpose of this universe is something that only God knows for sure, but it is increasingly clear to modern science that the universe was exquisitely fine-tuned to enable human life.

I shall propose to this Congress a $10 billion nationwide clean waters program to put modern municipal waste treatment plants in every place in America where they are needed to make our waters clean again, and do it now. We have the industrial capacity, if we begin now, to build them all within 5 years. This program will get them built within 5 years.

I tell my students, with a feeling of pride that I hope they will share, that the carbon, nitrogen, and oxygen that make up ninety-nine per cent of our living substance were cooked in the deep interiors of earlier generations of dying stars. Gathered up from the ends of the universe, over billions of years, eventually they came to form, in part, the substance of our sun, its planets, and ourselves. Three billion years ago, life arose upon the earth. It is the only life in the solar system.

I was there when Abbe Georges Lemaître first proposed this [Big Bang] theory. ... There is no rational reason to doubt that the universe has existed indefinitely, for an infinite time. .... It is only myth that attempts to say how the universe came to be, either four thousand or twenty billion years ago.
[Expressing his belief that the Big Bang is a myth devised to explain creation. He said he heard Lemaître (who was, at the time both a member of the Catholic hierarchy and an accomplished scientist) say in private that this theory was a way to reconcile science with St. Thomas Aquinas' theological dictum of creatio ex nihilo—creation out of nothing.]

I will give you a “celestial multiplication table.” We start with a star as the unit most familiar to us, a globe comparable to the sun. Then—
A hundred thousand million Stars make one Galaxy;
A hundred thousand million Galaxies make one Universe.
The figures may not be very trustworthy, but I think they give a correct impression.

If the earth’s population continues to double every 50 years (as it is now doing) then by 2550 A.D. it will have increased 3,000-fold. … by 2800 A.D., it would reach 630,000 billion! Our planet would have standing room only, for there would be only two-and-a-half square feet per person on the entire land surface, including Greenland and Antarctica. In fact, if the human species could be imagined as continuing to multiply further at the same rate, by 4200 A.D. the total mass of human tissue would be equal to the mass of the earth.

If there were a billion people living on the planet, we could do whatever we please. But there are nearly seven billion. At this scale, life as we know it today is not sustainable.

If we are still here to witness the destruction of our planet some five billion years or more hence ..., then we will have achieved something so unprecedented in the history of life that we should be willing to sing our swan song with joy.

If we ever establish contact with intelligent aliens living on a planet around a distant star … They would be made of similar atoms to us. They could trace their origins back to the big bang 13.7 billion years ago, and they would share with us the universe's future. However, the surest common culture would be mathematics.

If you go far enough out you can see the Universe itself, all the billion light years summed up time only as a flash, just as lonely, as distant as a star on a June night if you go far enough out. And still, my friend, if you go far enough out you are only at the beginning of yourself.

Imagine spending four billion years stocking the oceans with seafood, filling the ground with fossil fuels, and drilling the bees in honey production—only to produce a race of bed wetters!

In a dispassionate comparison of the relative values of human and robotic spaceflight, the only surviving motivation for continuing human spaceflight is the ideology of adventure. But only a tiny number of Earth’s six billion inhabitants are direct participants. For the rest of us, the adventure is vicarious and akin to that of watching a science fiction movie.

In a purely technical sense, each species of higher organism—beetle, moss, and so forth, is richer in information than a Caravaggio painting, Mozart symphony, or any other great work of art. Consider the typical case of the house mouse, Mus musculus. Each of its cells contains four strings of DNA, each of which comprises about a billion nucleotide pairs organized into a hundred thousand structural nucleotide pairs, organized into a hundred thousand structural genes. … The full information therein, if translated into ordinary-sized printed letters, would just about fill all 15 editions of the Encyclopaedia Britannica published since 1768.

In the beginning there were only probabilities. The universe could only come into existence if someone observed it. It does not matter that the observers turned up several billion years later. The universe exists because we are aware of it.

It is as if Cleopatra fell off her barge in 40 BC and hasn't hit the water yet.
[Illustrating how strange the behaviour of kaon particles, when first found in cosmic rays, which lived without predicted decay for a surprisingly long time—seemingly postponed a million billion times longer than early theory expected.]

It isn’t easy to become a fossil. … Only about one bone in a billion, it is thought, becomes fossilized. If that is so, it means that the complete fossil legacy of all the Americans alive today—that’s 270 million people with 206 bones each—will only be about 50 bones, one-quarter of a complete skeleton. That’s not to say, of course, that any of these bones will ever actually be found.

It took less than an hour to make the atoms, a few hundred million years to make the stars and planets, but five billion years to make man!

It’s humbling to realise that the developmental gulf between a miniscule ant colony and our modern human civilisation is only a tiny fraction of the distance between a Type 0 and a Type III civilisation – a factor of 100 billion billion, in fact. Yet we have such a highly regarded view of ourselves, we believe a Type III civilisation would find us irresistible and would rush to make contact with us. The truth is, however, they may be as interested in communicating with humans as we are keen to communicate with ants.

Let me describe briefly how a black hole might be created. Imagine a star with a mass 10 times that of the sun. During most of its lifetime of about a billion years the star will generate heat at its center by converting hydrogen into helium. The energy released will create sufficient pressure to support the star against its own gravity, giving rise to an object with a radius about five times the radius of the sun. The escape velocity from the surface of such a star would be about 1,000 kilometers per second. That is to say, an object fired vertically upward from the surface of the star with a velocity of less than 1,000 kilometers per second would be dragged back by the gravitational field of the star and would return to the surface, whereas an object with a velocity greater than that would escape to infinity.
When the star had exhausted its nuclear fuel, there would be nothing to maintain the outward pressure, and the star would begin to collapse because of its own gravity. As the star shrank, the gravitational field at the surface would become stronger and the escape velocity would increase. By the time the radius had got down to 10 kilometers the escape velocity would have increased to 100,000 kilometers per second, the velocity of light. After that time any light emitted from the star would not be able to escape to infinity but would be dragged back by the gravitational field. According to the special theory of relativity nothing can travel faster than light, so that if light cannot escape, nothing else can either. The result would be a black hole: a region of space-time from which it is not possible to escape to infinity.

Mammals in general seem to live, at best, as long as it takes their hearts to count a billion. To this general rule, man himself is the most astonishing exception.

Many billions of years will elapse before the smallest, youngest stars complete their nuclear burning and into white dwarfs. But with slow, agonizing finality perpetual night will surely fall.

More of cosmic history occurred in the first millisecond than has occurred in the ensuing 10 billion years.

Most educated people are aware that we're the outcome of nearly 4 billion years of Darwinian selection, but many tend to think that humans are somehow the culmination. Our sun, however, is less than halfway through its lifespan. It will not be humans who watch the sun's demise, 6 billion years from now. Any creatures that then exist will be as different from us as we are from bacteria or amoebae.

Nations have recently been led to borrow billions for war; no nation has ever borrowed largely for education… no nation is rich enough to pay for both war and civilization. We must make our choice; we cannot have both.

Only rarely do we see beyond the needs of humanity. … Now that we are over six billion hungry and greedy individuals, all aspiring to a first-world lifestyle, our urban way of life encroaches upon the domain of the living Earth. We are taking so much that it is no longer able to sustain the familiar and comfortable world we have taken for granted. Now it is changing, according to its own internal rules, to a state where we are no longer welcome.

Our highest claim to respect, as a nation, rests not in the gold, nor in the iron and the coal, nor in inventions and discoveries, nor in agricultural productions, nor in our wealth, grown so great that a war debt of billions fades out under ministrations of the revenue collector without fretting the people; nor, indeed, in all these combined. That claim finds its true elements in our systems of education and of unconstrained religious worship; in our wise and just laws, and the purity of their administration; in the conservative spirit with which the minority submits to defeat in a hotly-contested election; in a free press; in that broad humanity which builds hospitals and asylums for the poor, sick, and insane on the confines of every city; in the robust, manly, buoyant spirit of a people competent to admonish others and to rule themselves; and in the achievements of that people in every department of thought and learning.

Our sun is one of 100 billion stars in our galaxy. Our galaxy is one of billions of galaxies populating the universe. It would be the height of presumption to think that we are the only living things in that enormous immensity.

Producing food for 6.2 billion people, adding a population of 80 million more a year, is not simple. We better develop an ever improved science and technology, including the new biotechnology, to produce the food that’s needed for the world today. In response to the fraction of the world population that could be fed if current farmland was convered to organic-only crops: “We are 6.6 billion people now. We can only feed 4 billion. I don’t see 2 billion volunteers to disappear.” In response to extreme critics: “These are utopian people that live on Cloud 9 and come into the third world and cause all kinds of confusion and negative impacts on the developing countries.”

Pumbaa: “Timon, ever wonder what those sparkly dots are up there?”
Timon: “Pumbaa, I don’t wonder; I know.”
Pumbaa: “Oh. What are they?”
Timon: “They’re fireflies that got stuck up in that bluish-black thing”.
Pumbaa: “Oh, gee. I always thought they were balls of gas burning billions of miles away.”
Timon: “Pumbaa, with you, everything’s gas.”

Scientists constantly get clobbered with the idea that we spent 27 billion dollars on the Apollo programs, and are asked “What more do you want?” We didn't spend it; it was done for political reasons. ... Apollo was a response to the Bay of Pigs fiasco and to the successful orbital flight of Yuri Gagarin. President Kennedy's objective was not to find out the origin of the moon by the end of the decade; rather it was to put a man on the moon and bring him back, and we did that.

So there he is at last. Man on the moon. The poor magnificent bungler! He can't even get to the office without undergoing the agonies of the damned, but give him a little metal, a few chemicals, some wire and twenty or thirty billion dollars and, vroom! there he is, up on a rock a quarter of a million miles up in the sky.
[Written when the first manned mission to the Moon, Apollo 11, landed (20 Jul 1969).]

Sooner or later in every talk, [David] Brower describes the creation of the world. He invites his listeners to consider the six days of Genesis as a figure of speech for what has in fact been 4 billion years. On this scale, one day equals something like six hundred and sixty-six million years, and thus, all day Monday and until Tuesday noon, creation was busy getting the world going. Life began Tuesday noon, and the beautiful organic wholeness of it developed over the next four days. At 4 p.m. Saturday, the big reptiles came on. At three minutes before midnight on the last day, man appeared. At one-fourth of a second before midnight Christ arrived. At one-fortieth of a second before midnight, the Industrial Revolution began. We are surrounded with people who think that what we have been doing for that one-fortieth of a second can go on indefinitely. They are considered normal, but they are stark. raving mad.

Telescopes are in some ways like time machines. They reveal galaxies so far away that their light has taken billions of years to reach us. We in astronomy have an advantage in studying the universe, in that we can actually see the past.
We owe our existence to stars, because they make the atoms of which we are formed. So if you are romantic you can say we are literally starstuff. If you’re less romantic you can say we’re the nuclear waste from the fuel that makes stars shine.
We’ve made so many advances in our understanding. A few centuries ago, the pioneer navigators learnt the size and shape of our Earth, and the layout of the continents. We are now just learning the dimensions and ingredients of our entire cosmos, and can at last make some sense of our cosmic habitat.

Tell a man that there are 300 billion stars in the universe, and he’ll believe you. Tell him that a bench has wet paint upon it and he’ll have to touch it to be sure.

That a shutdown of existing reactors would be catastrophic I believe is self-evident. It is not only the energy that we would lose, it is the $100 billion investment whose write-off would cause a violent shock to our financial institutions.

The actuality of us being cognizant and accepting of the fact we are but a speck of sand in a universe sized desert, whose existence is irrelevant to any facet of universal function is a hard pill to swallow. Knowing the world will go on for another billion years after death and you will have no recollection of anything, just as you have no recollection of the billion years before your birth is a mind-boggling intuition.

The Earth has recovered after fevers like this, and there are no grounds for thinking that what we are doing will destroy Gaia, but if we continue business as usual, our species may never again enjoy the lush and verdant world we had only a hundred years ago. What is most in danger is civilization; humans are tough enough for breeding pairs to survive, and Gaia is toughest of all. What we are doing weakens her but is unlikely to destroy her. She has survived numerous catastrophes in her three billion years or more of life.

The earth, formed out of the same debris of which the sun was born, is extraordinarily rich in iron—iron which once may have existed at the center of a star that exploded many billions of years ago.

The Europeans and the Americans are not throwing $10 billion down this gigantic tube for nothing. We're exploring the very forefront of physics and cosmology with the Large Hadron Collider because we want to have a window on creation, we want to recreate a tiny piece of Genesis to unlock some of the greatest secrets of the universe.

The experiments that we will do with the LHC [Large Hadron Collider] have been done billions of times by cosmic rays hitting the earth. ... They're being done continuously by cosmic rays hitting our astronomical bodies, like the moon, the sun, like Jupiter and so on and so forth. And the earth's still here, the sun's still here, the moon's still here. LHC collisions are not going to destroy the planet.

The history of the universe is in every one of us. Every particle in our bodies has a multibillion-year past, every cell and every bodily organ has a multimillion-year past, and many of our ways of thinking have multithousand-year pasts.

The human mechanism is marvelous. But why not—it is the result of three-and-a-half billion years of tinkering.

The Industrial Revolution as a whole was not designed. It took shape gradually as industrialists and engineers figured out how to make things. The result is that we put billions of pounds of toxic materials in the air, water and soil every year and generate gigantic amounts of waste. If our goal is to destroy the world—to produce global warming and toxicity and endocrine disruption—we're doing great.

The most extensive computation known has been conducted over the last billion years on a planet-wide scale: it is the evolution of life. The power of this computation is illustrated by the complexity and beauty of its crowning achievement, the human brain.

The most wonderful mystery of life may well be the means by which it created so much diversity from so little physical matter. The biosphere, all organisms combined, makes up only about one part in ten billion of the earth’s mass. … Yet life has divided into millions of species, the fundamental units, each playing a unique role in relation to the whole.

The new naval treaty permits the United States to spend a billion dollars on warships—a sum greater than has been accumulated by all our endowed institutions of learning in their entire history. Unintelligence could go no further! … [In Great Britain, the situation is similar.] … Until the figures are reversed, … nations deceive themselves as to what they care about most.

The notion that individualism came first runs against the very grain of cosmic history. … grouping has been inherent in evolution since the first quarks joined to form neutrons and protons. Similarly, replicators—RNA, DNA, and genes—have always worked in teams… The bacteria of 3.5 billion years ago were creatures of the crowd. So were the trilobites and echinoderms of the Cambrian age.

The oceans are the life support system of this planet, providing us with up to 70 percent of our oxygen, as well as a primary source of protein for billions of people, not to mention the regulation of our climate.

The skein of human continuity must often become this tenuous across the centuries (hanging by a thread, in the old cliché), but the circle remains unbroken if I can touch the ink of Lavoisier’s own name, written by his own hand. A candle of light, nurtured by the oxygen of his greatest discovery, never burns out if we cherish the intellectual heritage of such unfractured filiation across the ages. We may also wish to contemplate the genuine physical thread of nucleic acid that ties each of us to the common bacterial ancestor of all living creatures, born on Lavoisier’s ancienne terre more than 3.5 billion years ago—and never since disrupted, not for one moment, not for one generation. Such a legacy must be worth preserving from all the guillotines of our folly.

The study of mathematics is apt to commence in disappointment. … We are told that by its aid the stars are weighed and the billions of molecules in a drop of water are counted. Yet, like the ghost of Hamlet's father, this greatest science eludes the efforts of our mental weapons to grasp it.

The study of mathematics is apt to commence in disappointment. The important applications of the science, the theoretical interest of its ideas, and the logical rigour of its methods all generate the expectation of a speedy introduction to processes of interest. We are told that by its aid the stars are weighed and the billions of molecules in a drop of water are counted. Yet, like the ghost of Hamlet's father, this great science eludes the efforts of our mental weapons to grasp it.

The Sun is all in all to us, the center from which all arises, but look wider, and it is only one of countless billions.

The United States this week will commit its national pride, eight years of work and $24 billion of its fortune to showing the world it can still fulfill a dream. It will send three young men on a human adventure of mythological proportions with the whole of the civilized world invited to watch—for better or worse.

The universe is simmering down, like a giant stew left to cook for four billion years. Sooner or later we won’t be able to tell the carrots from the onions.

The world's forests need to be seen for what they are—giant global utilities, providing essential public services to humanity on a vast scale. They store carbon, which is lost to the atmosphere when they burn, increasing global warming. The life they support cleans the atmosphere of pollutants and feeds it with moisture. They act as a natural thermostat, helping to regulate our climate and sustain the lives of 1.4 billion of the poorest people on this Earth. And they do these things to a degree that is all but impossible to imagine.

There is a point of view among astronomical researchers that is generally referred to as the Principle of Mediocrity. ... If the Sun and its retinue of worlds is only one system among many, then many other systems will be like ours: home to life. Indeed, to the extent that this is true, we should be prepared for the possibility that, even in the Milky Way galaxy, billions of planets may be carpeted by the dirty, nasty business known as life.

There once was a brainy baboon,
Who always breathed down a bassoon,
For he said, “It appears
That in billions of years
I shall certainly hit on a tune”.

This is the Jurassic Park for particle physicists... [The Large Hadron Collider is a time machine] ... Some of the particles they are making now or are about to make haven't been around for 14 billion years.

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.

Unavoidably, physics is usually expensive, and too many physicists find themselves with outdated or incomplete apparatus. The average factory worker in the United States has his productivity supported by a capital investment of $25,000 in machines and equipment. If physicists engaged in small science were as well supported as the average factory worker, they would share a total of ¾ billion dollars of depreciated equipment. I seriously doubt that they are that well supported.

Usually, only handfuls of dedicated amateur astronomers view such events. Billions of people saw Hale-Bopp. So, until a better comet comes along, it remains the great comet of our lives.

Walking home at night, I shine my flashlight up at the sky. I send billions of ... photons toward space. What is their destination? A tiny fraction will be absorbed by the air. An even smaller fraction will be intercepted by the surface of planets and stars. The vast majority ... will plod on forever. After some thousands of years they will leave our galaxy; after some millions of years they will leave our supercluster. They will wander through an even emptier, even colder realm. The universe is transparent in the direction of the future.

We are fishing out the top of the food chain, and it’s pretty crucial because about 200 million people depend on fish and fishing for their livelihood, and about a billion people, mostly in poorer countries, depend on fish for their protein. So this is a big problem. Good news is, it’s fixable.

We are the intelligent elite among animal life on earth and whatever our mistakes, [Earth] needs us. This may seem an odd statement after … the way 20th century humans became almost a planetary disease organism. But it has taken [Earth] 2.5 billion years to evolve an animal that can think and communicate its thoughts. If we become extinct she has little chance of evolving another.

We have come to look at our planet as a resource for our species, which is funny when you think that the planet has been around for about five billion years, and Homo sapiens for perhaps one hundred thousand. We have acquired an arrogance about ourselves that I find frightening. We have come to feel that we are so far apart from the rest of nature that we have but to command.

We have little more personal stake in cosmic destiny than do sunflowers or butterflies. The transfiguration of the universe lies some 50 to 100 billion years in the future; snap your fingers twice and you will have consumed a greater fraction of your life than all human history is to such a span. ... We owe our lives to universal processes ... and as invited guests we might do better to learn about them than to complain about them. If the prospect of a dying universe causes us anguish, it does so only because we can forecast it, and we have as yet not the slightest idea why such forecasts are possible for us. ... Why should nature, whether hostile or benign, be in any way intelligible to us? All the mysteries of science are but palace guards to that mystery.

We live on an obscure hunk of rock and metal circling a humdrum sun, which is on the outskirts of a perfectly ordinary galaxy comprised of 400 billion other suns, which, in turn, is one of some hundred billion galaxies that make up the universe, which, current thinking suggests, is one of a huge number—perhaps an infinite number—of other closed-off universes. From that perspective, the idea that we’re at the center, that we have some cosmic importance, is ludicrous.

When one ponders on the tremendous journey of evolution over the past three billion years or so, the prodigious wealth of structures it has engendered, and the extraordinarily effective teleonomic performances of living beings from bacteria to man, one may well find oneself beginning to doubt again whether all this could conceiveably be the product of an enormous lottery presided over by natural selection, blindly picking the rare winners from among numbers drawn at random. [Nevertheless,] a detailed review of the accumulated modern evidence [shows] that this conception alone is compatible with the facts.

When you look at the companies that have really won customers over in technology—say, Apple and Google—you find that they spend billions of dollars on R&D [research and development] each year, often spending that much on a product before they ever make a dime back in profits. Unfortunately, in the environment, I don’t see as much willingness to invest heavily in R&D as I do in consumer technology. And that’s a pity.

Why is the world five—or ten or twenty—billion years old?
Because it took that long to find that out.

With moth cytochrome C there are 30 differences and 74 identities. With bread yeast and humans, there are about 45 amino acids that are different and about 59 that are identical. Think how close together man and this other organism, bread yeast, are. What is the probability that in 59 positions the same choice out of 20 possibilities would have been made by accident? It is impossibly small. There is, there must be, a developmental explanation of this. The developmental explanation is that bread yeast and man have a common ancestor, perhaps two billion years ago. And so we see that not only are all men brothers, but men and yeast cells, too, are at least close cousins, to say nothing about men and gorillas or rhesus monkeys. It is the duty of scientists to dispel ignorance of such relationships.

Without ethics, everything happens as if we were all five billion passengers on a big machinery and nobody is driving the machinery. And it’s going faster and faster, but we don’t know where.