Knocking on Heaven's Door (13 page)

Faith requires active questioning, and many religions demand it of the observant. Yet at the same time, many religions, some branches of Protestantism among them, call for a rejection or suppression of independent will. In Calvin’s words: “Man by nature inclines to deluded self-admiration. Here, then, is what God’s truth requires us to seek in examining ourselves: it requires the kind of knowledge that will strip us of all confidence in our own ability, deprive us of all occasion for boasting, and lead us to submission.”
²⁴

These particular words applied primarily to moral questions. But the belief in the necessity for external guidance is unscientific, and it can be difficult to know where to draw the line.

The struggle between the desire for knowledge and the mistrust of human pride reverberates throughout religious literature, including the Herbert poems that Fish and the Roundtable participants discussed. The Cambridge conversation elaborated on Herbert’s inner conflicts about his relationships with knowledge and with God. For Herbert, self-generated understanding was a sign of sinful pride. Similar warnings appear in the writings of John Milton. Although he firmly believed in the necessity for robust intellectual inquiry, he nonetheless has Raphael tell Adam in
Paradise Lost
that he should not inquire too curiously into the motion of the stars, for “they need not thy belief.”

Surprisingly (at least to me), notable representatives of our group of Harvard and MIT professors in attendance at the roundtable event approved of Herbert’s attempts at self-renunciation, believing it was a good thing to suppress one’s individuality and align oneself with this greater force. (Anyone who knows Harvard and MIT professors would also be surprised at this alleged denial of ego.)

Maybe the question of whether people can access truth on their own is the real issue at the heart of the religion/science debate. Is it possible that the negative attitudes toward science we hear today are partially rooted in the admittedly extreme beliefs expressed by Herbert and Milton? I’m not sure we are arguing so much about how the world came to be as about who has a right to figure things out and whose conclusions we should trust.

The universe is humbling. Nature hides many of its most interesting mysteries. Yet scientists are arrogant enough to believe we can solve them. Is it blasphemous to search for answers or is it merely presumptuous? Einstein as well as the Nobel Prize—winning physicist David Gross described scientists as thinking they are wrestling with God in order to learn the answers to the big questions about how nature works. David certainly didn’t mean this literally (and certainly not humbly)—he was recognizing our miraculous ability to intuit the world around us.

This legacy of not trusting our ability to figure things out for ourselves continues in other respects as well, when we see it in humor, movies, and a good deal of today’s politics. Sincerity and respect for facts have become somewhat unfashionable in our ironic and often anti-intellectual era. The degree to which some people will go to deny the successes of science can be amazing. I was once at a party where I met someone who boldly insisted to me that she didn’t believe in science. So I asked her whether she had taken the same elevator to the eleventh floor that I had. Did her phone work? How did her electronic invitation reach her?

Many people still consider it embarrassing or at best quaint to be earnest about facts or logic. One source of anti-intellectual antiscientific sentiment might be resentment at the act of egotism in a person feeling powerful enough to tackle the world. Those who have an underlying sense that we don’t have the right to take on enormous intellectual challenges believe these are the domain of higher powers than we possess. This peculiar anti-ego, anti-progress trend can still be heard in the playground and the country club.

For some individuals, the idea that you can decipher the world is a source of optimism and leads to a sense of greater understanding and influence. But for others, science and scientific authorities who know more and have greater skill in these technical areas are a source of fear. People divide themselves according to who feels qualified to engage in scientific activities and to evaluate scientific conclusions, and who feels left out and powerless in the face of scientific thought and therefore views such pursuits as acts of ego.

Most people want to feel empowered and to experience a sense of belonging. The question each individual faces is whether religion or science offers a greater sense of control over the world. Where do you find trust, comfort, and understanding? Do you prefer to believe that you can figure things out for yourself or at least trust fellow humans to do so? People want answers and guidance that science can’t yet provide.

Nonetheless, science has told us much about what the universe is made of and how it works. When you put together all of what we know, the picture scientists have deduced over time fits together miraculously well. Scientific ideas lead to correct predictions. So some of us trust in its authority, and many recognize the remarkable lessons of science through the ages.

We constantly move beyond human intuition as we explore regions to which we don’t have immediate access, and we have yet to make discoveries that bring back the centrality of humans in our description of the world. The Copernican revolution consistently repeats itself as we realize how we are just one of many sets of objects of a random size in a random place in what appears—in the scientific viewpoint—to be a randomly operating universe.

People’s curiosity and the ability to make progress toward satisfying this hunger for information make humanity very special indeed. We are the one species equipped to ask questions and systematically chip away to find the answers. We question, we interact, we communicate, we hypothesize, we make abstractions, and in all of this we end up with a richer view of the universe and our place within.

This doesn’t mean that science necessarily will answer all questions. People who think science will solve all human problems are probably on the wrong track as well. But it does mean that the pursuit of science has been and will continue to be a worthwhile endeavor. We don’t yet know all the answers. But scientifically inclined people, whether or not they have religious faith, try to pry open the universe and find them. Part II explores what they’ve found so far and what’s now on the horizon.

SCALING MATTER

THE MAGICAL MYSTERY TOUR

Though the ancient Greek philosopher Democritus might have started off on the right track when he posited the existence of atoms 2,500 years ago, no one could have accurately guessed what the true elementary components of matter would turn out to be. Some of the physical theories that apply at small distances are so counterintuitive that even the most creative and open-minded people would never have imagined them if experiments hadn’t forced scientists to accept their new and confounding premises. Once scientists of the last century had the technology to probe atomic scales, they found that the inner structure of matter repeatedly defied expectations. The pieces fit together in a way that is far more magical than anything we will see on a stage.

Any human being will have difficulty creating an accurate visual image of what’s going on at the minuscule scales that particle physicists study today. The elementary components that combine to form the stuff we recognize as matter are very different from what we access immediately through our senses. Those components operate according to unfamiliar physical laws. As scales decrease, matter seems to be governed by properties so different that they appear to be part of entirely different universes.

Many confusions in trying to comprehend this strange inner structure arise from lack of familiarity with the variety of ingredients that emerge at different scales and the range of sizes at which different theories most readily apply. We need to know what exists and to have a sense of the sizes and scales that different theories describe in order to fully understand the physical world.

Later on we will explore the different sizes relevant to space, the final frontier. This chapter first looks inward, starting with familiar scales and ending deep in the interior of matter—the other final frontier. From commonly encountered length scales to the innards of an atom (where quantum mechanics is essential) to the
Planck scale
(where gravity would be as powerful as the other known forces), we’ll explore what we know and how it all fits together. Let’s now take a tour of this remarkable inner landscape that enterprising physicists and others have deciphered over time.

SCALING THE UNIVERSE

Our journey begins at human scales—the ones we see and touch in our daily lives. It’s no coincidence that a meter—not one-millionth of a meter and not ten thousand meters—is, roughly speaking, the size of a person. It’s about twice the size of a baby and half the size of a fully grown man. It would be rather strange to find that the basic unit we use for common measurements was one-hundredth the size of the Milky Way or the length of an ant’s leg.

Nonetheless, a standard physical unit defined in terms of any particular human wouldn’t be all that useful since a measuring stick should be a length we all agree on and understand.
²⁵
So in 1791, the French Academy of Sciences established a standard. A meter was to be defined either as the length of a pendulum with a half period of one second or one ten-millionth of the length of the Earth’s meridian along a quadrant (that is the distance from the Equator to the North Pole).

Neither definition has much to do with us humans. The French were simply trying to find an objective measure that we could all agree on and be comfortable with. They converged on the latter choice of definition to avoid the uncertainties introduced by the slightly varying force of gravity over the surface of the Earth.

The definition was arbitrary. It was designed to make the measure of a meter precise and standard so that everyone could agree on what it was. But one ten-millionth was no coincidence. With the official French definition, a meter stick is something you can comfortably hold in your hands.

Most of us are better approximated by two meters, but none of us are 10, or even three meters in height. A meter is a human scale, and when objects are this size, we’re pretty comfortable with them—at least insofar as our ability to observe and interact with them (we’ll stay away from meter-long crocodiles). We know the rules of physics that apply since they are the ones we witness in our daily existence. Our intuition is based on a lifetime of observing objects and people and animals whose size can be reasonably described in terms of meters.

I sometimes find it remarkable how constrained our comfort zone can be. The NBA basketball player Joakim Noah is a friend of my cousin. My family and I never tire of commenting on his height. We can look at photos or marks on a door frame charting his height at various ages and marvel at him blocking a smaller guy’s shot. Joakim is mesmerizingly tall. But the fact is, he is only about 15 percent taller than the average human being, and his body works pretty much like everyone else’s. The exact proportions might be different, sometimes giving a mechanical advantage and sometimes not. But the rules his bones and muscles follow are pretty much the same that yours do.

Newton’s laws of motion, written down in 1687, still tell us what happens when we apply force to a given mass. They apply to the bones in our body and they apply to the ball Joakim throws. With these laws we can calculate the trajectory of a ball he tosses here on Earth and predict the path the planet Mercury takes when orbiting the Sun. In all cases, Newton’s laws tell us that motion will continue at the same speed unless a force acts on the object. That force will accelerate an object in accordance with its mass. An action will induce an equal and opposite reaction.

Newton’s laws work admirably for a well-understood range of lengths, speeds, and densities. Disparities appear only at the very small distances where quantum mechanics changes the rules, at extremely high speeds where relativity applies, or at enormous densities such as those in a black hole where general relativity takes over.

The effects of any of the new theories that supersede Newton’s laws are too small to ever be observed at ordinary distances, speeds, or densities. But with determination and technology we can reach the regimes where we encounter these limitations.

JOURNEY INSIDE

We have to travel a ways down before we encounter new physics components and new physical laws. But a lot goes on in the range of scales between a meter and the size of an atom. Many of the objects we encounter in our daily existence as well as in life itself have important features we can notice only when we explore smaller systems where different behaviors or substructures become prominent. (See Figure 13 for some scales that we refer to in this chapter.)

Of course, a lot of objects we’re familiar with are made by simply putting together a single fundamental unit many times, with few details or any internal structure of interest. These
extensive systems
grow like walls of bricks. We can make walls bigger or smaller by adding more or fewer bricks, but the basic functional unit is always the same. A large wall is in many respects just like a small wall. This type of scaling is exemplified in many large systems that grow with the number of repeated elementary components. This applies, for example, to many large organizations as well as computer memory chips that are composed of large numbers of identical transistors.

A different type of scaling that applies to other types of large systems is exponential growth, which occurs when the connections, rather than the fundamental elements, determine a system’s behavior. Although such systems too grow by adding many similar units, the behavior depends on the number of connections—not just the number of basic units. These connections don’t extend just to an adjacent part, as with bricks, but can extend to other units across the system. Neural systems composed of many synaptic connections, cells with many interacting proteins, and the Internet with a large number of connected computers are all examples. This is a worthy subject of study in itself, and some forms of physics also deal with related emergent macroscopic behavior.