A Logic Gate Made of People

“I don’t know your names,” Von Neumann said, tapping the shoulders of two of the soldiers. “The two of you will be responsible for signal input, so I’ll call you ‘Input 1’ and ‘Input 2.’” He pointed to the last soldier. “You will be responsible for signal output, so I’ll call you ‘Output.’” He shoved the soldiers to where he wanted them to stand. “Form a triangle. Like this. Output is the apex. Input 1 and Input 2 form the base.” “You could have just told ...

 The DNA Prism

The standard DNA 'prism' is a gel electrophoresis column, that is, a long tube filled with jelly through which an electric current is passed. A solution containing the scissored stretches of DNA, all jumbled together, is poured into one end of the tube. The DNA fragments are all electrically attracted to the negative end of the column, which is at the other end of the tube, and they move steadily through the jelly. But they don't all move at the same rate. Like light of low vibration frequenc...

 Science of the Rainbow

The spectrum depends upon light of different colours being slowed by different amounts: the refractive index of a given substance, say glass or water, is greater for blue light than for red. You could think of blue light as being a slower swimmer than red, getting tangled up in the undergrowth of atoms in glass or water because of its short wavelength. Light of all colours gets less tangled up among the sparser atoms of air, but blue still travels more slowly than red. In a vacuum, where ther...

 Unweaving the Rainbow Makes it More Beautiful

Newton's unweaving of the rainbow led on to spectroscopy, which has proved the key to much of what we know today about the cosmos. And the heart of any poet worthy of the title Romantic could not fail to leap up if he beheld the universe of Einstein, Hubble and Hawking. We read its nature through Fraunhofer lines - 'Barcodes in the Stars' - and their shifts along the spectrum. The image of barcodes carries us on to the very different, but equally intriguing, realms of sound ('Barcodes on the ...

 Darwin and the Origins of Life

There is a curious parallelism between Darwin's twenty-year delay in publishing his theory of evolution and Newton's {102} twenty-year delay in publishing the Principia. And Newton's refusal to publish his cosmological speculations finds a parallel in Darwin's silence concerning the problem of the origin of life. If we are to understand in general terms the place of life in the universe, we must also understand life's origin. Darwin explicitly excluded the origin of life from the scope of ...

 Newton's Perspective on the Universe

As all regions below are replenished with living creatures, (not only the Earth with Beasts, and Sea with Fishes and the air with Fowls and Insects, but also standing waters, vineger, the bodies and blood of Animals and other juices {49} with innumerable living creatures too small to be seen without the help of magnifying glasses) so may the heavens above be replenished with beings whose nature we do not understand. He that shall well consider the strange and wonderful nature of life and th...

 Science Unifiers

Now it is generally true that the very greatest scientists in each discipline are unifiers. This is especially true in physics. Newton and Einstein were supreme as unifiers. The great triumphs of physics have been triumphs of unification. We almost take it for granted that the road of progress in physics will be a wider and wider unification bringing more and more phenomena within the scope of a few fundamental principles. Einstein was so confident of the correctness of this road of unificati...

 Bottom-Up VS Top-Down Method for Finding Laws

Broadly speaking, to discover new regularities and laws we either follow top–down or the bottom–up approach (Fig. 1). In the top–down approach, the search begins with an external observation e.g., Newton’s laws of motion. The observer intuitively imagines a set of elements, a set of interactions and a mathematically expressible form to connect the two. Components are weaved into a mental map and experiments are planned to verify or nullify the model. If the experimental observations r...

 Simultaneous Invention

Thomas Edison invented the light bulb in 1879. What if he had never been born, Would we still have light bulbs? And would they still have been invented in 1879? It turns out that this is not just a philosophical question and the answer is yes, the light bulb would have been invented at roughly the same time. We know this because at least 23 other people built prototype light bulbs before Edison1, including two groups who filed patents and fought legal battles with him over the rights (Sawyer ...

 Overbeliefs

The "overbeliefs" of an enlightened man rest on the firmest basis of reality available. This he finds in the scientific picture of the universe of his age. On this foundation of natural knowledge he erects a unique unproven structure of "overbeliefs" concerning his universe, origin, life, hereafter, religion and God. "A man's religion must not give the lie to the world in which he lives. It must be as intelligent as Man". If the overbeliefs of an individual cannot be proven inconsistent with ...