November 25 was the 100th anniversary of Einstein’s general theory of relativity, so now that we’re in December — and with time continuing to move forward, or some of it, anyway — let’s review how the theory transformed our understanding of space and time.
- Space is essentially storage space. The general theory of relativity proves that space, in its essence, is convenient storage space for matter and energy. Einstein famously remarked that space was a vast closet for organizing everything from stars and planets and moons to birds and trees and shoes. When asked if space could be regarded as God’s closet, Einstein winked and answered: “Perhaps the closet of God’s wife.”
- Time is not easy to find. Relativity theory reveals that time is extremely elusive, and that the most challenging aspect of studying it is simply finding it. In fact, many scientists now believe that Einstein’s crucial breakthrough came when he could not find the time to study time, and, in a revolutionary response, decided he would make the time to do so. Thus we have Einstein to blame for the burden of always having to make time for things we really don’t have time to do.
- The words “space” and “time” should always be spelled backwards, as ecaps and emit, in order to convey the unusual character of what they signify. Einstein demonstrated that time and space, or space-time, could bend and curve, fold and ripple, and wrap itself around a massive object while whistling a Broadway show tune. To highlight the bizarre nature of such phenomena, Einstein insisted on writing many key words backwards. He sometimes even scrambled all the letters in a sentence, which led to sentences like: “Eth yhtore si fditulicf.” This partly explains why his ideas are hard for most people to understand.
- Time usually moves sideways. In 1915, a key principle of standard physics held that time always moved forward. With his elegant equations, however, Einstein proved that time moved forward only 14.2 percent of the time, when enough good people got together and pushed it forward. In the absence of people who actually were good — such as progressives who fought for the passage of child labor laws — time generally moved sideways and sometimes even backward.
- Time and space are like entangled lovers. Though their connection may not in fact be amorous, time and space behave suspiciously like lovers who live in a tight and complicated embrace. In developing his general theory, Einstein spent years on the awkward task of simply prying time and space apart so that he could get a better look at them. When he did finally manage to disentangle them and observe them as separate entities — cold, naked, shivering and pathetic as they were — he noted they were much less impressive alone than together.