A star-forming region known as N90. See credit below.
Brian Greene’s “The Illusion of Time, part of the series “The Fabric of the Cosmos” aired Sunday evening, July 22, 2012, on “Nova” on PBS. Here’s a summary, followed by a couple of thoughts.
“Time is not what it seems…There may be no distinction between the past, present, and future.” Discoveries in quantum physics suggest that time is entirely different from how we perceive it to be in our daily lives.
All cultures, including very ancient ones, have found time fascinating. The Maya for example calculated time with three different, interrelated calendars; for the sun, the moon, and Venus.
The Crab Nebula. See credit below.
In our search to measure time, the rotation of the earth and its revolution around the sun became our first clock.
Today, instead of measuring the earth’s rotation, the atomic clock measures the frequency of the cesium atom, which, in one second ticks 9 billion, 192 million times.
Asking the question, “Time is a mystery. What is it we’re actually measuring?” Brian Greene recalled the work of Einstein.
For Newton, time had been absolute and immutable. But with Einstein, time is experienced differently by each of us, and is affected by motion through space and time. Time and space are linked, and one person’s time is not the same as another’s. Although time moves more slowly for a person in motion, this is not something that we can observe in our everyday lives, but scientific experiments have proven that this is true.
The Orion Nebula. See credit below.
By an experiment in which a jet plane circled the earth and time was measured by atomic clocks on the plane and on the ground, it was demonstrated that time moved more slowly on the plane, which was in motion, than it did on the earth.
The sharp differentiation that we make between past, present and future is an illusion because, Brien Greene explained, according to Einstein, “Time and space are fused together as space/time.”
In a different galaxy thousands of light years distant, an alien who is riding on a bicycle away from us, would not (assuming that he could look at us through his telescope) see us as we are in the present; instead he would see us in the past – perhaps during the time of Beethoven. If the same alien were riding towards us on his bicycle, he would see us, not in the present, but in the future – perhaps as we will be 200 years from now. So, says Brian Greene, “Past, present, and future are all equally real….the future is not non-existent….Einstein shattered the distinction between past, present, and future.”
Just as, in a movie, every frame already exists on film, the flow of time, from a past that exists to a future that does not yet exist, is an illusion.
Though we think of wormholes as something belonging to science fiction, Einstein’s equations actually predict them, and they would provide gateways through both space and time. Perhaps even if we don’t jump into them, we might just peer through them as a window to view what is far, far away, what has been, or what will be.
One of the most puzzling aspects of time is that it is one directional, though there is theoretically no reason why time should not flow in both directions. There is simply the fact that it doesn’t. The laws of physics do say in fact that time could go backwards, so the question asked is “Why doesn’t it?” If one drops a wine glass and it shatters, one can’t reverse the action and have all the pieces streaming back together again. Our lives go irreversibly in one direction, which leads to the question, “What is responsible for the arrow of time?”
Entropy is randomness, meaning that everything has a tendency to move toward disorder, like the pages of a book that fall apart, but do not fall back together again.
Billowing smoke becomes disordered. Degrees of messiness increase.
The Mystic Mountain in the Carina Nebula. See credit below.
This problem of the directionality of time seems to be solved by taking entropy into account. The arrow of time comes from the tendency of nature to move towards increasing disorder. If one goes all the way back to the Big Bang, one arrives at a highly ordered situation.
At a single moment at the beginning, all matter was compressed neatly into one single point, all precisely ordered. After that came the beginning of disorder. The universe expanded and spread out. It can’t be put back, like the genie can’t be put back into the lamp. So, at the Big Bang, the arrow of time was given its direction toward disorder. “Time is a 13.7 billion year old drive toward disorder.”
Scientists, who used to assume that the expansion of the universe was slowing over time, had a rude awakening a few years ago, with the discovery that the expansion of the universe is accelerating – going faster and faster, and the galaxies are hurtling away from each other. One day, our descendants will see no other galaxies, and the cosmic past will be out of reach. Eventually there will be no movement and no time. Brian Greene summed it up by saying, “The flow of time is an illusion…We are part of a far richer and far stranger reality.”
A thought or two
“The Illusion of Time” is very fascinating and brilliantly presented, though it does come to a rather grim ending. (We can’t, of course, hold scientists responsible for how the universe ends.)
However, interestingly, the idea that time and space are illusory is not new at all. It is at least 5,000 years old – maybe 10,000 – maybe it is a timeless concept that has always been there.
The ancient texts of India describe time and space as illusory, as maya, having the appearance of reality, but not having the quality of ultimate reality. We do not see the world as it truly is because of the veil of maya, just as, on a cloudy day, we do not see the sun hidden behind the cloud cover. We do not see the true nature of time and space, until the veil is removed from our eyes.
Concerning the concept of entropy, long ago Hindu seers wrote that there are four ages – each on a lower, baser level than the last, until one arrives at the fourth, last age, the Kali Yuga, the age where we find ourselves now—an age of dishonesty, corruption, and negativity. This is an example of entropy – of traveling inexorably from order to disorder.
The concept of time as linear is, by and large, a western concept. In eastern thought, time tends to be not linear, but cyclical. The four ages, the yugas, are one day in the life of Brahma, the Creator. At the end of this day, Brahma goes to sleep, and then at dawn he awakens, ready to start a new day composed of another four ages. Of course it’s somewhat more complicated, but that is a rough outline of what happens. The four ages are one day in the life of Brahma.
This concept has a few things to be said for it – for one, it is not grim; for another, it has not only a poetic quality, but also a truthful quality. And it transcends the problem of being stuck in a purely physical reality.
Brian Greene is a brilliant physicist who has taken us on an amazing journey into a strange world, a very thought-provoking journey.
Physicists of today are by no means limiting themselves to a linear view, quite the contrary. There is the concept of multiverses. (Brian Greene examines this in other programs, as part of the “Fabric of the Cosmos” series.) This is the idea that there may not be just one universe, but countless or infinite parallel worlds; and one individual may exist in many of these at the same time or different times. Have you ever felt that you were in more than one place?
A book that takes a look at this possibility is “2012” by Whitney Strieber.
It’s basically a horror novel, but if you don’t mind the horror bits too much (I did actually mind, but found the book intriguing anyway), it is fascinating reading.
Then, from another angle altogether, there is the legend of the Chinese general who lost a very important battle. It is said that the reason he lost the battle is that many years later, mistakes were made in the liturgy of his funeral. The mistakes caused his life to be less auspicious and therefore led to the loss of the battle. I suppose, if we are not too confused already, we could meditate on this as an alternate view of time and destiny.
In all societies of the past, ancient spiritual traditions recognized many levels of reality. There is the material level of everyday life where we walk along on our journey from day to day, but there are also the broader, more sunlit levels above, of mystical or magical realities from which we see with different eyes – seeing farther and more clearly—beyond the bounds of time and space. The things we cannot see from this earthly level, can be seen from other levels, as if we are looking out the window of an airplane or riding on a magic bird that flies above the clouds.
“ESA/Hubble images, videos and web texts are released under the Creative Commons Attribution 3.0 Unported license and may on a non-exclusive basis be reproduced without fee provided they are clearly and visibly credited.”
Top photo: Credit: NASA, ESA and the Hubble Heritage Team STScI/AURA)-ESA/Hubble Collaboration / A star-forming region known as N90, on the outskirts of the Small Magellanic Cloud.
Second photo: NASA, ESA and Allison Loll/Jeff Hester (Arizona State University). Acknowledgement: Davide De Martin (ESA/Hubble) / The Crab Nebula. Observers in China and Japan recorded the supernova nearly 1,000 years ago, in 1054
Third photo: Credit: NASA,ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team / The Orion Nebula
Fourth photo: Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) / The Carina Nebula: The Mystic Mountain
For more Hubble images and information, click here.
For more on the Nova series, “The Fabric of Time”, click here.