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The reason this principle is so essential to science is that it’s the beginning of understanding how we came to be here and how everything works. We look for general principles that apply to the universe as a whole first, and those explain much of the story; and then we look for the quirks and exceptions that led to…
I am afraid all we can do is to accept the paradox and try to accommodate ourselves to it, as we have done to so many paradoxes lately in modern physical theories. We shall have to get accustomed to the idea that the change of the quantity R, commonly called the 'radius of the universe', and the evolutionary changes…
For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal…
When I pause and reflect on our expanding universe, with its galaxies hurtling away from one another, embedded within the ever-stretching, four-dimensional fabric of space and time, sometimes I forget that uncounted people walk this Earth without food or shelter, and that children are disproportionately represented…
1.How faint are the farthest objects? The Hubble observations detected objects as faint as 30th magnitude. The faintest objects the human eye can see are at sixth magnitude. Ground-based telescopes also can detect 30th-magnitude objects. Those objects, however, are so dim they are lost in the glare of brighter, nearby…
In a bravura passage, Darwin also considers Herschel’s disturbing suggestion that the entire cosmos may eventually wither back into ‘one dark centre’. This implies that the universe not only had a beginning, but will have a physically destructive end, a ‘Big Crunch’. There are hints here too of Milton’s vision of the…
There is a place with four suns in the sky – red, white, blue, and yellow; two of them are so close together that they touch, and star-stuff flows between them. I know of a world with a million moons. I know of a sun the size of the Earth – and made of diamond. There are atomic nuclei a mile across that rotate thirty…
In fact, our own universe is very likely itself a vast black hole. We have no knowledge of what lies outside our universe. This is true by definition, but also because of the properties of black holes. Objects that reside in them cannot ordinarily leave them. In a strange sense, our universe may be filled with objects…
The fate of individual human beings may not now be connected in a deep way with the rest of the universe, but the matter out of which each of us is made is intimately tied to processes that occurred immense intervals of time and enormous distances in space away from us. Our Sun is a second- or third-generation star…
The first step occurs when older stars start to accumulate helium, which is produced when two hydrogen nuclei collide and fuse with each other. This fusion is how stars create the energy that warms us. Two helium atoms can in turn collide to form beryllium, an atom whose nucleus contains four protons. Once beryllium…
If one assumes that a few hundred million years in stable orbit are necessary for planetary life to evolve, the number of space dimensions is also fixed by our existence. That is because, according to the laws of gravity, it is only in three dimensions that stable elliptical orbits are possible. Circular orbits are…
By examining the model universes we generate when the theories of physics are altered in certain ways, one can study the effect of changes to physical law in a methodical manner. It turns out that it is not only the strengths of the strong nuclear force and the electromagnetic force that are made to order for our…