Blinkby John Flynn]
Marlene and I used this tune as the opening for our 50th Wedding Anniversary celebration. It contains so many truths about how time is perceived by most of us. I believe the song shows a facet of how humans remember events. It seems that time is what we experience in our now,
as flowing through us. Most of us briefly anticipate the immediate future, experience the now of things, and then are able to recall events that just happened a short time ago, all while actively anticipating the next event. I am inviting you to consider the possibility that time, as we think we know it might be something different. That difference may be due to the way we perceive.
Those of you who know me know that I am a physicist. I tend to believe I was born that way. As a youth I watched the washing machine run through its cycles over and over until I could understand what it was doing and why it worked that way. I did the same with the clothes dryer, the furnace, the water heater, the large family freezer, the lawnmower, and the thermostat. Anything that moved. Outside the house I asked, Why did the sunrise change positions with the change in seasons?
I had many questions.
The job of a physicist is to figure out how things work. The way that things work in our everyday world can be very well described by physics that has been around since Newton invented calculus. We build cars, bridges, buildings and for almost everything we use the physics of Newton. Lately that is not all together true. Computers, Lasers, and modern electronics, while mostly Newtonian in nature are infused with some non-Newtonian physics.
Newton thought of the world as having three independent dimensions, length, width, and depth. And Newton thought of Time as a steady flow in which these three dimensions acted out to present reality as it steadily marched forward, unaffected by any other influence. It is as if some god had set a metronome ticking and the frames of the 3-D world evolved at a steady pace. This is the way time is held by nearly all people today. If you believe this, a lot of nice things can be explained. Then, things happen in a specific order. If a woman is 20 years old and you don’t see her for 10 years, when you see her again, she is 30 years old We can account for every second in those 10 years (almost one third of a billion seconds). That about wraps it up, Right? Well, not really.
I started to think about time during the same period that I was thinking about washing machines. I was very Newtonian then, and a lot of people agreed with me. However, slowly, things started to get a little weird. I noticed that time only moved in one direction. It turns out that other people noticed that, too. Ludwig Boltzmann lived during the latter part of the 19th century and studied random motion and developed the kinetic theory of gasses. This, he discovered provided a reason for time moving only in one direction. At that time there was no law or other indication in Newtonian physics that time should have a preferred direction. The equations developed to explain motion say things can move in either direction, either forward or backward. So, why do things always go only in one direction? For example, you never see two cars jump from a rumpled mess and spring back into two undented vehicles moving away from each other. But many of you have witnessed two undented vehicles colliding together into a crumpled mess. Why do you see it only one way if physics allows for both?
What Boltzmann proposed was that when things happen heat is produced, things become more random and things cannot get more ordered all by themselves. He said randomness is always increasing and that makes time move forward and not backward. People had a hard time accepting this because it was new. Nobody believed him and he ended his life in despair. The debate raged and his ideas were found to be so much closer to the truth. Again, people like to hold on to ideas they are used to.
Just like me! There was a time in my early youth when I thought that the days of unimproved roads were in our long-ago past. When I was 4 or 5 years old, everywhere I looked I saw paved streets with sidewalks. I assumed that since people had been here a long time that it was like this everywhere; I was very surprised to learn that people still lived alongside dirt roads. It was an awakening that I would later recall in my school-day musings: I learned how whole civilizations viewed their place in the universe as how it was everywhere.
There was a time when most people thought that the world was flat (some still do!) and the sun, moon, planets, and stars all went around us. Well, the world sure looks flat and all those things sure circle around, every day. But most of you know the story about trying to make sense of things when more details are leaned and confirmed. Things that were thought to exist, like perfect circular motions, and planet epicycles, moving celestial spheres, gave way to observations such as eclipses, and phases of Venus, and as more and more data accumulated the old ideas could no longer be stretched to fit the observations. Some things that seem obvious at first sight just do not make sense when we are able to grasp more general, simpler, and more logical perspectives.
However, whenever a new concept, like a spherical Earth or heliocentricity, is first introduced there are not just perceptual changes that must be overcome. In the example of the spherical earth the vocabulary needed to convey the understanding is not always in the vernacular of the people who are asked to swallow this idea. New words must be introduced and learned before the concept can be conveyed.
Imagine explaining to your friend who believes that the earth is flat that the concept of up
changes depending on where you are standing. On a sphere if you point up from where you are standing you might be pointing to an overhead star, but if you pointed in the same manner while standing on a different location on a spherical Earth you would be pointing in a different direction entirely. Up
here is different than Up
there, although it still feels the same. Imagining explaining that “Up” is relative to your location when you have no language or meaning to assign to the different meanings for Up
! The explanation makes sense to us now, but to flat-Earthers then it was nearly incomprehensible.
This was made very clear to me and I was totally taken by surprise while traveling to the Southern Hemisphere for the first time and saw the constellation Orion. Orion was upside down! (I was upsidedown!) Everyone on Earth still uses the expression, I saw the sunrise this morning.
Everyone understands what you mean, even though you really described that while you were standing still you traveled on the Earth’s rotating surface in a North-Easterly direction to watch the sun travel across the sky in a south westerly direction. We tend to relate to things from our own perspective and have a really hard time incorporating other views. If more than a few people agree with your perspective, then it is really hard to shake the accepted view.
Imagine this! Have you ever been sitting in a stationary car in a parking lot and without you being aware, the car next to you begins to slowly back out of the slot? Did you hit the brakes to avoid running into the car in front of you, because you think your car is drifting forward? That has happened to me a couple of times. The point is this: In order to understand how things work, how much perspective is required and when the point arrives that you know you have enough information to make a decision is all based on two things: 1. The correct observation and 2. Your belief. The correct observation is very important, but so is belief. It is belief that allows you to feel good about your decision regarding the observation.
I have set up the main problem with time. We know what it looks like on Earth and why it moves forward. Is it correct? We’ll address this after the Offertory.
Now we are set to address a larger complicating issue of perspective. Modern time-measuring equipment requires more and more accuracy to be useful. It wasn’t until about 1680 that minute hands were added to pocket watches, and as time became more important, increasingly exact time measurements were needed. For example, today if you use GPS to locate your position on Earth, you need to know what time it is very accurately. Being off by 1 microsecond can cause your calculated position to be way off. Accuracies to 15 nanoseconds are being used for GPS technologies.
The problem that Einstein worked on most of his life is that time does not flow everywhere at a constant rate. The faster you move with respect to something else that something else measures your time at a slower rate of flow. What this means, is that if we see a clock travel past us, Time is passing more slowly than for an identical clock we have sitting right next to us. This is not Newtonian! This goes against our sense of time. In addition, if that clock changes speed or enters a gravitational field, the rate of time passing will slow down additionally. This has been verified using two identical atomic clocks. One placed on the Earth and the other put into orbit. The rate of time moved more slowly for the one on Earth.
Now, the age differences between people in orbit and those stuck on Earth is real, but not noticeable. However, if we use satellites for time comparisons, corrections must be reconciled if we are to use the data from the orbiting clock for GPS and communication. Einstein provided equations for those corrections and they have been confirmed over the ensuing decades and used successfully as needed ever since 1905.
However, what this does mean is that if we venture too far away from the Earth the universe will look much different from what we think if we maintain our Newtonian perspective. If we stick close to this planet, time proceeds pretty much as most of us think it does. But, if we start to go away, then things start to get weird for us.
I had my first inkling of this during the moon landing 50 years ago. When we were listening to the conversation between the ground-based control center and the astronauts, there was a three second gap between the end of the question and the beginning of the astronaut’s response. The moon is about 250,000 miles away from earth and light travels at 186,000 miles/s. So, by the time a person speaks, the message is received, and the response is heard there must be a gap of at least 2.86 seconds. Einstein’s equations, again, patch things up to account for these effects, but, the door to a new perspective on physics has been opened. When distances such as these are approached, relativistic effects become noticeable and the homocentric perspective becomes obvious.
As distances get large, other weirder things can happen. For example, the order of events becomes less clear. Supernova explosions from distant events may occur in different order depending on the location and speed of the observer. Noncausal events can occur in any order if you pick the right spot. Einstein’s equations can account for these observations, too. But, the concept of time and the flow of time that we hold on Earth have been built from our natural surroundings. We must build a new perspective if we are to confidently understand the universe. The common perception of events and durations is not the same on Earth as they are far away from Earth.
So, what does that mean for us? How are we impacted, and what can we conclude about the future that we assemble from our observations? These realizations were for me the beginning of my faith crisis. A universe that allows contradictions is unfathomable to me. I have never encountered a contradiction in nature.
All humans have a belief system on which they rely. Whether it involves a Sun God that makes the Sun go around the Earth, a Devil that waits to make you pay for your sins, or a kind ancient entity that benevolently guides life in the Universe. Every human believes in something on which they hang their conclusions and meanings. Growing up as a physicist I adopted as my premises the following:
This is why a faith crisis is in full swing for me. I have always tried to understand things and believed that with more information events would become more understandable and more reasonable. I’ve seen how past ideas were replaced by new understandings that brought me, and people in general, closer to what the world was truly like. For the first time I wonder if the human perception is adequate enough to attempt a consistent characterization of reality. (I am questioning premise #2.) I had previously realized that our understanding of the universe would always be incomplete, but I believed it was adequate enough to approach an accurate view of reality.
Now I am wondering if humanity is fatally flawed and doomed to remain mired in misperception, if we are doomed to be insurmountably homocentric. That critical and ugly error seems to pop its head over and over again.
I have discovered that some of the most intrinsic beliefs seem to have a major bias is the result of our naive earth-based perception. For a person who has spent his life trying to figure out what is really going on, this is an unnerving discovery.
I have an optimistic hope that the human perspective can be made wide enough to encompass the essence of nature. Peter Mayer put words to an old hymn that shows us the challenge of this mystery. I’d like to leave you with Blue Boat Home which brings to my mind many of today’s ideas. The Earth is our only boat home.
Blue Boat Homeby Peter Mayer]
My hope is that you, too, will question the perceptions you have always held as true. My awakening began from my search to understand the concept of time. The conclusions I have drawn do not apply only to physics. They apply to most human experience.
For you, look a little closer at your interpersonal relationships, your racial biases, your environmental awareness or your political viewpoints. Look everywhere. How we perceive things and how they really are, is difficult to assess. Reviewing your perspective is always worth the effort. You will be able to leave some of your flat-Earth ideas behind?
Copyright © 2020 Rob Lieb. All Rights Reserved.