The most beautiful experience we can have is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. Whoever does not know it and can no longer wonder, no longer marvel, is as good as dead, and his eyes are dimmed. It was the experience of mystery--even if mixed with fear--that engendered religion.
--Albert Einstein
In the opening quote, Einstein splendidly captures the sense of awe that accompanies the cutting edge of scientific discovery. The scientist stands in wonder at the incomprehensible majesty of the universe, from the most minute constituents of matter to immense clusters of galaxies to the elegant natural laws that give it all coherence. What are some of these great mysteries of science?
What is matter? The objects of the material world seem so real. Yet if we look deeply, this reality begins to fade. The overwhelming majority of each atom--99.9999999999999 percent--is empty space. Probing the protons and neutrons of the atom, we find them also to be nearly total emptiness containing pointlike particles called quarks. What, if anything, makes up the quarks? No one knows.*
But why are there quarks and electrons? Physicists have developed "string theory" to try to explain their existence. According to this idea, the elementary particles arise as vibrations of ten- or eleven-dimensional space-time membranes (called "p-branes"). We do not experience these extra dimensions because they are so tightly curved in on each other that they are beyond our senses. If quarks and electrons have any size at all, it likely comes from the scale of the vibrating p-branes rather than any solid surface. We are left with the disconcerting thought that matter itself may well be an illusion caused by the wiggles of space-time.
What is reality? The Newtonian world of our ordinary senses is a comfortingly rational place. Effect follows cause as time inexorably unfolds. But the deeper realm of quantum mechanics seems an unfathomable mystery. Even in a vacuum, matter pops in and out of existence. Such behavior, called "quantum fluctuations," is not caused by anything; it just happens randomly. Things like electrons are both waves and particles. This microscopic world of quantum physics is a supreme mystery. How can we visualize an electron as being both a wave and a particle, or matter fluctuating into and out of existence? Quantum mechanics allows us to calculate observable quantities to astonishing precision, so we must take it seriously, but the view of the physical world that it presents us is really incomprehensible.
Ultimate questions. Countless people have gazed at the blazing night sky and asked where it all came from and perhaps even why there is a universe. Such profound questions are at the forefront of modern scientific speculation.
The universe is held together by the four fundamental forces of gravitation, electromagnetism, the weak force, and the strong nuclear force. But why these and no others, and where did they come from? Matter everywhere seems to obey the same fundamental laws, but where did these laws come from, and why do they have their particular form? Were they somehow determined by chance at the beginning of the universe, or is there some underlying reason for them? As Einstein said, "What really interests me is where God had any choice in the creation of the world."
The universe appears to have begun some twelve to fifteen billion years ago--the so-called Big Bang. But why did the Big Bang occur? Some astronomers speculate that new universes (or "multiverses") are being created all the time. If so, are the physical laws in them the same as in our multiverse, or are they totally different? And--the most profound mystery of all--why is there a universe in the first place? Why is there something rather than nothing?
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*The same is true of the electron. Although it is not made up of quarks, its internal structure (if it has any) is presently unknown.
--Wayne Anderson, "Why Should People Choose Science Over Religion?" Free Inquiry, Fall 2001, pp. 58-59