— And Other Cosmic Quandaries
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Prologue: The Beginning Of Science
The chessboard that is our universe has revealed some of its rules, but much of the cosmos still behaves mysteriously—as though there remain secret, hidden regulations to which it abides. These would be rules not found in the rule book we have thus far written.
Does any of this sound like the end of science? Does any of this sound like we are on top of the situation? Does any of this sound like it’s time to congratulate ourselves?
1. Coming To Our Senses
what we gain in breadth we lose in precision: we register the world’s stimuli in logarithmic rather than linear increments. For example, if you increase the energy of a sound’s volume by a factor of 10, your ears will judge this change to be rather small.
The stellar magnitude scale of brightness, the well-known acoustic decibel scale, and the seismic scale for earthquake severity are each logarithmic, in part because of our biological propensity to see, hear, and feel the world that way.
the persistent failures of controlled, double-blind experiments to support the claims of parapsychology suggest that what’s going on is nonsense rather than sixth sense.
the quote that opens this chapter, while poignant and poetic, should have instead been: Equipped with our five senses, along with telescopes and microscopes and mass spectrometers and seismographs and magnetometers and particle accelerators and detectors across the electromagnetic spectrum, we explore the universe around us and call the adventure science.
Modern Physics impresses us particularly with the truth of the old doctrine which teaches that there are realities existing apart from our sense-perceptions,
Science expands beyond our direct senses, leaving less and less space for the "supernatural".
3. Seeing Isn’T Believing
If most of the stars we see are highly luminous, then surely those stars are common throughout the galaxy. Nope again. High-luminosity stars are the rarest of them all.
If you jumped vertically, wouldn’t you land in a very different spot as Earth traveled swiftly beneath your feet? (You don’t.)
4. The Information Trap
One of the challenges of scientific inquiry is knowing when to step back—and how far back to step—and when to move in close. In some contexts, approximation brings clarity; in others it leads to oversimplification. A raft of complications sometimes points to true complexity and sometimes just clutters up the picture.
5. Stick-In-The-Mud Science
Perhaps these ancient observatories perennially impress modern people because modern people have no idea how the Sun, Moon, or stars move. We are too busy watching evening television to care what’s going on in the sky. To us, a simple rock alignment based on cosmic patterns looks like an Einsteinian feat. But a truly mysterious civilization would be one that made no cultural or architectural reference to the sky at all.
Ignorance on part of modern people is what led to underestimation of what ancient civilizations could achieve.
6. Journey From The Center Of The Sun
Curiously, the odds are that the drunkard will not return to the lamppost. If the steps are indeed random, distance from the lamppost will slowly accumulate.
For every absorption and re-emission, the high-energy gamma-ray photons tend to give birth to multiple lower-energy photons at the expense of their own existence.
7. Planet Parade
the author established that what Lowell saw on Venus was actually the network of shadows cast on Lowell’s own retina by his ocular blood vessels. When you compare Lowell’s diagram of the spokes with a diagram of the eye, the two match up, canal for blood vessel. And when you combine the unfortunate fact that Lowell suffered from hypertension—which shows up clearly in the vessels of the eyeballs—with his will to believe, it’s no surprise that he pegged Venus as well as Mars with teeming with intelligent, technologically capable inhabitants.
Nor is there any shortage of evidence that liquid water once flowed on the Martian surface: the planet has (dry) meandering riverbeds as long and wide as the Amazon, webs of (dry) tributaries, (dry) river deltas, and (dry) floodplains. The Mars exploration rovers, inching their way across the dusty rock-strewn surface, confirmed the presence of surface minerals that form only in the presence of water.
The concept of a habitable zone incorporated an initial bias that room temperature is just right for life. But some organisms just love several-hundred-degree hot tubs and find room temperature downright hostile. To them, we are the extremophiles. Many places on Earth, previously presumed to be unlivable, such creatures call home: the bottom of Death Valley, the mouths of hot vents at the bottom of the ocean, and nuclear waste sites, to name just a few.
The question becomes: what kinds of environments would life be more LIKELY to arise, since they can survive fine through diversification into all these "extremes"?
8. Vagabonds Of The Solar System
ONLY CERES—the largest of the asteroids, at about 580 miles in diameter—is spherical. The others are much smaller, craggy fragments shaped like doggy bones or Idaho potatoes. Curiously, Ceres alone accounts for about a quarter of the total asteroidal mass.
the orbits of Oort Cloud comets extend halfway to the nearest stars.
9. The Five Points Of Lagrange
If you actually got sick on such a ride, and turned your head to the side, the vomit would fly off at a tangent.
trajectories that begin at Lagrangian points require very little fuel to reach other Lagrangian points or even other planets.
10. Antimatter Matters
the universe remains disturbingly imbalanced: when created, every antiparticle is always accompanied by its particle counterpart, yet ordinary particles seem to be perfectly happy without their antiparticles. Are there hidden pockets of antimatter in the universe that account for the imbalance?
11. The Importance Of Being Constant
Planck’s insight was that you could account for the full sweep of the emitted spectrum in one equation only if you assume that energy itself is quantized, or divided up into itty bitty units that cannot be subdivided further: quanta.
13. Going Ballistic
Were Earth’s surface not in the way, all these objects would execute perfect, albeit elongated, orbits around Earth’s center.
On timescales of hundreds of millions of years—periods much longer than the ones considered by Laplace—planetary orbits are chaotic. A situation that leaves Mercury vulnerable to falling into the Sun, and Pluto vulnerable to getting flung out of the solar system altogether. Worse yet, the solar system might have been born with dozens of other planets, most of them now long lost to interstellar space.
15. Over The Rainbow
DURING THE LATE 1800S, with the widespread use of spectrographs in astronomy, coupled with the new science of photography, the field of astronomy was reborn as the discipline of astrophysics.
Astrophysics educators face a pedagogical challenge of the highest rank. Astrophysics researchers deduce nearly all knowledge about the structure, formation, and evolution of things in the universe from the study of spectra. But the analysis of spectra is removed by several levels of inference from the things being studied. Analogies and metaphors help, by linking a complex, somewhat abstract idea to a simpler, more tangible one.
That is why the public hardly ever hears about the role of spectra in cosmic discovery—it’s just too far removed from the objects themselves to explain efficiently or with ease.
The problem here is that after you view such exhibits, you leave waxing poetic about the beauty of the universe yet you are no closer than before to understanding how it all works. To really know the universe requires forays into levels 3, 4, and 5.
16. Cosmic Windows
The remnant manifests itself as an omnipresent and omnidirectional ocean of light that is dominated by microwaves.
The energy emitted by the Sun, whose surface temperature is about 6,000 degrees absolute, includes plenty of infrared, but peaks in the visible part of the spectrum, as does the sensitivity of the human retina, which, if you have never thought about it, is why our sight is so useful in the daytime.
17. Colors Of The Cosmos
light sources that are truly yellow make white things look yellow. So if the Sun were pure yellow, then snow would look yellow—
Let’s just focus on his canals and green patches of vegetation. Percival was the unwitting victim of two well-known optical illusions. First, in almost all circumstances, the brain attempts to create visual order where there is no order at all. The constellations in the sky are prime examples—the result of imaginative, sleepy people asserting order on a random assortment of stars. Likewise, Lowell’s brain interpreted uncorrelated surface and atmospheric features on Mars as large-scale patterns. The second illusion is that gray, when viewed next to yellow-red, appears green-blue
18. Cosmic Plasma
The most conspicuous plasmas on Earth are fire, lightning, the trail of a shooting star, and of course, the electric shock you get after you shuffle around on your living room carpet in your wool socks and then touch a doorknob.
Every shooting star is a tiny particle of interplanetary debris moving so fast that it burns up in the air, harmlessly descending to Earth as cosmic dust. Almost the same thing happens to spacecraft that reenter the atmosphere. Since their occupants don’t want to land at their orbital speed of 18,000 miles per hour (about five miles per second), the kinetic energy must go somewhere. It turns into heat on the leading edge of the craft during reentry and is rapidly whisked away by the heat shields. In this way, unlike shooting stars, the astronauts do not descend to Earth as dust.
WHILE RELATIVELY RARE on Earth, plasmas comprise more than 99.99 percent of all the visible matter in the cosmos.
This layer reflects certain frequencies of radio waves, including those of the AM dial on your radio. Because of this property of the ionosphere, AM radio signals can reach hundreds of miles
20. Dust To Dust
Thus we face an odd situation: to create a star with a 10-million-degree core, hot enough to undergo thermonuclear fusion, we must first achieve the coldest possible conditions within a cloud.
22. Send In The Clouds
If you fuse iron, or anything heavier, the reaction absorbs energy instead of emitting it.
consider the cloud’s top ingredients: atoms of hydrogen, helium, oxygen, carbon, and nitrogen. Sound familiar? Except for helium, which is chemically inert, those elements are the main ingredients of life as we know it. Given the stunning variety of molecules those atoms can form, both with themselves and with others, they are also likely to be the ingredients of life as we don’t know it.
Carbon monoxide (CO), for instance, stabilizes long before the carbon condenses into dust, and molecular hydrogen (H2) becomes the prime constituent of cooling gas clouds, now sensibly called molecular clouds. Among the triatomic molecules that form next are water (H2O), carbon dioxide (CO2), hydrogen cyanide (HCN), hydrogen sulfide (H2S), and sulfur dioxide (SO2). There’s also the highly reactive triatomic molecule H3+, which is eager to feed its third proton to hungry neighbors, instigating further chemical trysts.
As the cloud continues to cool, dropping below 100 degrees Kelvin or so, bigger molecules arise, some of which may be lying around in your garage or kitchen: acetylene (C2H2), ammonia (NH3), formaldehyde (H2CO), methane (CH4). In still cooler clouds you can find the chief ingredients of other important concoctions: antifreeze (made from ethylene glycol), liquor (ethyl alcohol), perfume (benzene), and sugar (glycoaldehyde), as well as formic acid, whose structure is similar to that of amino acids, the building blocks of proteins.
The current inventory of molecules drifting between the stars is heading toward 130. The largest and most structurally intricate of them are anthracene (C14H10) and pyrene (C16H10)
23. Goldilocks And The Three Planets
What if the Sun were mysteriously plucked from the center of the solar system and Earth spun out of orbit, adrift in space? This event would surely not merit attention in the thermophile press. But in 5 billion years, the Sun will become a red giant as it expands to fill the inner solar system. Meanwhile, Earth’s oceans will boil away and Earth, itself, will vaporize. Now that would be news.
Life, far from being rare and precious, may be as common as planets themselves.
24. Water, Water
water’s most remarkable feature is that, while most things—water included—shrink and become denser as they cool, water expands when it cools below 4 degrees Celsius, becoming less and less dense.
Without this density inversion below 4 degrees, whenever the outside air temperature fell below freezing, the upper surface of a bed of water would cool and sink to the bottom as warmer water rose from below. This forced convection would rapidly drop the water’s temperature to zero degrees as the surface begins to freeze. The denser, solid ice would sink to the bottom and force the entire bed of water to freeze solid from the bottom up. In such a world, there would be no ice fishing because all the fish would be dead—fresh frozen.
25. Living Space
Molecules made of just two atoms form early: carbon monoxide and the hydrogen molecule (hydrogen atoms bound together in pairs). Drop the temperature some more, and you get stable three-or four-atom molecules such as water (H2O), carbon dioxide (CO2), and ammonia (NH3)—simple but top-shelf ingredients in the kitchen of life. Drop the temperature even more, and hordes of five-and six-atom molecules form. And because carbon is both abundant and chemically enterprising, most of the molecules include it; indeed, three-quarters of all molecular “species” sighted in interstellar space have at least one carbon atom.
If somewhere there’s another celestial body that bears any resemblance to our own planet, it may have run similar experiments with its similar chemical ingredients, and those experiments would have been choreographed by the physical laws that hold sway throughout the universe. Consider carbon. Its capacity to bind in multiple ways, both to itself and to other elements, gives it a chemical exuberance unequalled in the periodic table. Carbon makes more kinds of molecules (how does 10 million grab you?) than all other elements combined. A common way for atoms to make molecules is to share one or more of their outermost electrons, creating a mutual grip analogous to the fist-shaped coupler between freight cars. Each carbon atom can bind with one, two, three, or four other atoms in this way, whereas a hydrogen atom binds with only one, oxygen with one or two, and nitrogen with three. By binding to itself, carbon can generate myriad combinations of long-chain, highly branched, or closed-ring molecules. Such complex organic molecules are ripe for doing things that small molecules can only dream about. They can, for example, perform one kind of task at one end and another kind at the other; they can coil and curl and intertwine with other molecules, creating no end of features and properties.
Life elsewhere might be more similar to us than we imagined.
The biologist who has Earth-on-the-brain may revel in life’s diversity, but the astrobiologist dreams of diversity on a grander scale: life based on alien DNA, or on something else entirely. Sadly, our planet is a singular biological sample. Nevertheless, the astrobiologist may glean insights about life-forms that dwell elsewhere in the cosmos by studying organisms that thrive in extreme environments here on Earth.
the weight of evidence has tilted in favor of the view that extremophiles were the earliest earthly life-forms.
you’ve got single-celled organisms emerging from the primordial ooze within a mere 200 million years. Even though scientists continue to be stumped about how life began, nature clearly had no trouble creating the stuff.
One problem with silicon—apart from its being a tenth as abundant as carbon—is the strong bonds it creates. When you link silicon and oxygen, for instance, you don’t get the seeds of organic chemistry; you get rocks.
26. Life In The Universe
In the absence of dogma and data, it is safer to be guided by the notion that we are not special, which is generally known as the Copernican principle,
The same goes to the notion that physical law were treaked to make life possible: to assume life is something worth or needing tweaking is seeing ourselves as too important.
The elements hydrogen, oxygen, and carbon account for over 95 percent of the atoms in the human body and all known life.
Is life chemically special? The Copernican principle suggests that it probably isn’t. Aliens need not look like us to resemble us in more fundamental ways. Consider that the four most common elements in the universe are hydrogen, helium, carbon, and oxygen. Helium is inert. So the three most abundant, chemically active ingredients in the cosmos are also the top three ingredients in life on Earth. For this reason, you can bet that if life is found on another planet, it will be made of a similar mix of elements. Conversely, if life on Earth were composed primarily of, for example, molybdenum, bismuth, and plutonium, then we would have excellent reason to suspect that we were something special in the universe.
27. Our Radio Bubble
At current broadcast strengths from Earth, aliens 100 light-years away would require a radio receiver that was fifteen times the collecting area of the 300-meter Arecibo telescope (the world’s largest) to detect a television station’s carrier signal.
28. Chaos In The Solar System
The general public knows intuitively, if not explicitly, that science makes predictions, but it may surprise people to learn that science can also predict that something is unpredictable. Such is the basis of chaos.
we have gone from not knowing the motions of the planets to knowing that we cannot know the evolution of the solar system into the unlimited future—
31. Galactic Engines
One’s ability to describe and understand a new phenomenon is always limited by the contents of the prevailing scientific and technological toolbox. An eighteenth-century person who was briefly, but unwittingly, thrust into the twentieth century would return and describe a car as a horse-drawn carriage without the horse and a lightbulb as a candle without the flame. With no knowledge of internal combustion engines or electricity, a true understanding would be remote indeed. With that as a disclaimer, allow me to declare that we think we understand the basic principles of what drives a quasar.
Fertile scientific models are always seductive, but one should occasionally ask whether the model is fertile because it captures some deep truths about the universe or because it was constructed with so many tunable variables that you can explain anything at all. Have we been sufficiently clever today, or are we missing a tool that will be invented or discovered tomorrow?
The English physicist Dennis Sciama knew this dilemma well when he noted:
Since we find it difficult to make a suitable model of a certain type, Nature must find it difficult too. This argument neglects the possibility that Nature may be cleverer than we are. It even neglects the possibility that we may be cleverer to-morrow than we are to-day.
32. Knock ’Em Dead
WHEN YOU’RE A hammer (as the saying goes), all your problems look like nails. If you’re a meteorite expert pondering the sudden extinction of boatloads of species, you’ll want to say an impact did it. If you’re an igneous petrologist, volcanoes did it. If you’re into spaceborne bioclouds, an interstellar virus did it. If you’re a hypernova expert, gamma rays did it.
34. Things People Say
Aristotle also made other kinds of claims. He said that heavy things fall faster than light things. Who could argue against that? Rocks obviously fall to the ground faster than tree leaves.
Aristotle’s teachings were later adopted into the doctrines of the Catholic Church. And through the Church’s power and influence Aristotelian philosophies became lodged in the common knowledge of the Western world, blindly believed and repeated. Not only did people repeat to others that which was not true, but they also ignored things that clearly happened but were not supposed to be true.
The Church, with its unmatched authority, declares the stars don’t change. The population then falls victim to a collective delusion that was stronger than its members’ own powers of observation.
We all carry some blindly believed knowledge because we cannot realistically test every statement uttered by others. When I tell you that the proton has an antimatter counterpart (the antiproton), you would need $ 1 billion worth of laboratory apparatus to verify my statement. So it’s easier to just believe me and trust that, at least most of the time, and at least with regard to the astrophysical world, I know what I am talking about. I don’t mind if you remain skeptical. In fact, I encourage it. Feel free to visit your nearest particle accelerator to see antimatter for yourself.
The North Star is the brightest star in the nighttime sky. The Sun is a yellow star. What goes up must come down. On a dark night you can see millions of stars with the unaided eye. In space there is no gravity. A compass points north. Days get shorter in the winter and longer in the summer. Total solar eclipses are rare.
Every spot in space is teeming with countless gravitational tugs in the direction of every other object in the universe.
The constellation lore of Western cultures owes its origin and richness to centuries of Babylonian, Chaldean, Greek, and Roman imaginations. Remember, these are the same imaginations that gave rise to the endless dysfunctional social lives of the gods and goddesses. Of course, these were all Northern Hemisphere civilizations, which means the constellations of the southern sky (many of which were named only within the last 250 years) are mythologically impoverished.
When people believe a tale that conflicts with self-checkable evidence it tells me that people undervalue the role of evidence in formulating an internal belief system. Why this is so is not clear, but it enables many people to hold fast to ideas and notions based purely on supposition.
35. Fear Of Numbers
we are not wired for logical thinking. If we were, then mathematics would be the average person’s easiest subject in school.
Without these comparisons, and without the reminder that these failures were consistent with the “faster, cheaper, better” paradigm, in which risks are spread among multiple missions, you would think that 1 billion equals $ 1 trillion.
36. On Being Baffled
Maybe it’s the need to attract and keep readers. Maybe the public likes to know those rare occasions when scientists are clueless. But how come science writers can’t write an article about the universe unless they describe some of the astrophysicists they interview as being “baffled” by the latest research headlines?
If the writers told the whole truth, they would instead report that all astrophysicists are baffled daily, whether or not their research makes headlines. Scientists cannot claim to be on the research frontier unless one thing or another baffles them. Bafflement drives discovery.
Richard Feynman, the celebrated twentieth-century physicist, humbly observed that figuring out the laws of physics is like observing a chess game without knowing the rules in advance. Worse yet, he wrote, you don’t get to see each move in sequence. You only get to peek at the game in progress every now and then. With this intellectual handicap, your task is to deduce the rules of chess.
I would be remiss if I did not include the discovery of neutron stars, which pack the mass of the Sun within a ball that measures barely a dozen miles across. To achieve this density at home, just cram a herd of 50 million elephants into the volume of a thimble.
Lest I leave you with the impression that the behavior of research scientists is indistinguishable from that of freshly beheaded chickens running aimlessly around the coop, you should know that the body of knowledge about which scientists are not baffled is impressive. It forms most of the contents of introductory college textbooks and comprises the modern consensus of how the world works. These ideas are so well understood that they no longer form interesting subjects of research and are no longer a source of confusion.
38. Let There Be Dark
When viewed from the Moon’s near side, Earth looks thirteen times bigger,
39. Hollywood Nights
Half of any month the Moon’s phase is neither crescent nor full. Did the artists paint what they saw or what they wished they had seen?
40. In The Beginning
Or what if you went to a sumo wrestling match after work and saw the two spherical gentlemen collide, disappear, then spontaneously become two beams of light?
If those scenes played out daily, then modern physics wouldn’t look so bizarre, knowledge of its foundations would flow naturally from our life experience, and our loved ones probably would never let us go to work.
Back in the early minutes of the universe, though, that stuff happened all the time. To envision it, and understand it, one has no choice but to establish a new form of common sense, an altered intuition about how physical laws apply to extremes of temperature, density, and pressure.
41. Holy Wars
The claims of science rely on experimental verification, while the claims of religions rely on faith. These are irreconcilable approaches to knowing, which ensures an eternity of debate wherever and whenever the two camps meet.
I have yet to see a successful prediction about the physical world that was inferred or extrapolated from the content of any religious document. Indeed, I can make an even stronger statement. Whenever people have tried to make accurate predictions about the physical world using religious documents they have been famously wrong. By a prediction, I mean a precise statement about the untested behavior of objects or phenomena in the natural world, logged before the event takes place.
Most scientific claims made on the frontier will ultimately be disproved, due primarily to bad or incomplete data, and occasionally to blunder. But the scientific method, which allows for expeditions down intellectual dead ends, also promotes ideas, models, and predictive theories that can be spectacularly correct. No other enterprise in the history of human thought has been as successful at decoding the ways and means of the universe.
Science
42. The Perimeter Of Ignorance
the authors invoke divinity only when they reach the boundaries of their understanding. They appeal to a higher power only when staring into the ocean of their own ignorance. They call on God only from the lonely and precarious edge of incomprehension. Where they feel certain about their explanations, however, God gets hardly a mention.
ambrosia.
But why confine ourselves to things too wondrous or intricate for us to understand, whose existence and attributes we then credit to a superintelligence? Instead, why not tally all those things whose design is so clunky, goofy, impractical, or unworkable that they reflect the absence of intelligence?
And what comedian configured the region between our legs—an entertainment complex built around a sewage system?
Stupid design could fuel a movement unto itself. It may not be nature’s default, but it’s ubiquitous. Yet people seem to enjoy thinking that our bodies, our minds, and even our universe represent pinnacles of form and reason. Maybe it’s a good antidepressant to think so.
Driven by fear