HOW hard you try you will never be able to grasp just how tiny, how spatiallyunassuming, is a proton. It is just way too small.
A proton is an infinitesimal part of an atom, which is itself of course an insubstantial thing.
Protons are so small that a little dib of ink like the dot on this i hold something in theregion of 500,000,000,000 of them, rather more than the number of seds tained in halfa million years. So protons are exceedingly microscopic, to say the very least.
Now imagine if you (and of course you 』t) shrinking one of those protons down to abillionth of its normal size into a spaall that it would make a proton look enormous.
Now pato that tiny, tiny space about an ounatter. Excellent. You are ready to starta universe.
I』m assuming of course that you wish to build an inflationary universe. If you』d preferio build a more old-fashioned, standard Big Bang universe, you』ll need additionalmaterials. In fact, you will o gather up everything there is every last mote and partiatter between here and the edge of creation and squeeze it into a spot so infinitesimallypact that it has no dimensions at all. It is known as a singularity.
Iher case, get ready for a really big bang. Naturally, you will wish to retire to a safeplace to observe the spectacle. Unfortunately, there is o retire to because outside thesingularity there is no where. When the universe begins to expand, it won』t be spreading outto fill a larger emptiness. The only space that exists is the space it creates as it goes.
It is natural but wrong to visualize the singularity as a kind nant dot hanging in adark, boundless void. But there is no spao darkness. The singularity has no 「around」
around it. There is no space for it to occupy, no place for it to be. We 』t even ask how longit has been there—whether it has just lately popped into being, like a good idea, or whether ithas been there forever, quietly awaiting the right moment. Time does. There is no pastfor it to emerge from.
And so, from nothing, our universe begins.
In a single blinding pulse, a moment of glory much too swift and expansive for any form ofwords, the singularity assumes heavenly dimensions, space beyond ception. In the firstlively sed (a sed that many ologists will devote careers to shaving into ever-finerwafers) is produced gravity and the other forces that govern physics. Ihan a miheuniverse is a million billion miles across and growing fast. There is a lot of heat now, tenbillion degrees of it, enough to begin the nuclear reas that create the lighter elements—principally hydrogen and helium, with a dash (about oom in a hundred million) oflithium. In three minutes, 98 pert of all the matter there is or will ever be has beenproduced. We have a universe. It is a place of the most wondrous and gratifying possibility,aiful, too. And it was all done in about the time it takes to make a sandwich.
When this moment happened is a matter of some debate. ologists have long arguedover whether the moment of creation was 10 billion years ago or twice that or something iween. The sensus seems to be heading for a figure of about 13.7 billion years, but thesethings are notoriously difficult to measure, as we shall see further on. All that really besaid is that at some ierminate point in the very distant past, for reasons unknown, therecame the moment known to sce as t = 0. We were on our way.
There is of course a great deal we don』t know,