As requested
As requested
Being Swept into Battle
My first impression at seeing this thread was WHAT? Bob is as deep as he has ever been in a theological debate, and he has time to compose a post this long and detailed on a subject completely apart from the debate subject. Miracles most assuredly have not ceased. My surprise received partial answer when I was privately contacted with the information that Bob feels this question may have relevance to the debate he is involved in.
To what I hope is a very minor degree, I seem to have been swept from the position of a silent observer to a pawn in the shadows on the outskirts of this theological contest. And I hadn’t even said which side I was rooting for. I have just learned battles are dangerous and should only be viewed from very great distances.
Some Questions are Worth Asking
Bob’s post starting this thread is rather long, and the question an excellent one. Long before he gave voice to this question, it was likewise proposed by some of the best physicists, and often occurs to physics students in their studies. It has elicited a number of responses in this thread. I will not comment on those, even though several have done a good job of touching on the same ideas as I do. A quick-and-simple reply to Bob from me would leave as many questions as it answered. I don’t think it necessary, or even advisable to turn this thread into a tutorial on Relativity. Bob himself has touched on the essence of the issues involved.
I do want to make sure we have a very clear understanding (and hopefully agreement) on the nature of this daily commodity that we all experience as time. It is seriously misunderstood. I would be foolish to think that my answer will put the issue to rest for all. But I do hope it helps give Bob insights into the issue that he may not have been presented before.
Bob’s Search for an Answer
I note that this Relativity question is one that Bob has had in mind for several years. On October 30th, 2000 on BEL Bob pursued this question with a fellow Christian who was a Physicist studying relativity. Perhaps Bob felt as I did after listening to the show, there were some interesting ideas expressed, but a clear answer to the question Bob is pursuing here was not really forthcoming in that exchange. I pray (I use that verb for Bob’s benefit, since I as an agnostic would nominally use the verb “hope”) that I can come a bit closer to a definitive answer.
The Essence of Bob
As I read over Bob’s post, I see several key passages that encapsulate the core of his arguments. These are the things I will be responding to:
Genesis says that God gave us the Sun (and other astronomic bodies) for “seasons, and for days and years.” It turns out that God gave mankind great timekeepers <referring to the sun, moon, and stars> (and less misleading ones than our atomic clocks as interpreted by theorists)! The movements within our solar system give us a more correct understanding of the absolute nature of time than do the ticks of atomic clocks.
Gravity does not affect time: it affects clocks. And that is not the same thing. If gravity affected actual time, then like tomorrow’s paper, the summit clock should be one day into the actual future as compared to the base clock; and if it were quickly transported down the mountain (where it would begin experiencing the same rate of time as the other clock), then the summit clock would continue to give readouts of twenty-four hours in the future, as compared to the base clock.
Well, since the earth originally orbited the Sun in exactly 360 days, the ancients divided circles into 360 degrees …
Bob’s Lost Day
Let me consider this first:
If gravity affected actual time, then like tomorrow’s paper, the summit clock should be one day into the actual future as compared to the base clock; and if it were quickly transported down the mountain (where it would begin experiencing the same rate of time as the other clock), then the summit clock would continue to give readouts of twenty-four hours in the future, as compared to the base clock.
Bob correctly goes partway toward the resolution of this problem in his recognition that both clocks saw the same number of sunrises and sunsets. Yet one clock was running faster than the other, until it had pulled a full day ahead. How can that be? Hidden in this claim is lack of recognition of what clocks really measure.
The meaning of the word day is going to be important in this discussion. What is a day? A satisfactory answer would be that a day is the period from sunrise to sunrise (assuming a cloudless sky).
Do clocks measure days? For the vast majority of clocks, the answer is no. My watch doesn’t, yours doesn’t, nor any clock in my home or car and probably yours as well. Why do I say that, when everyone of us come to work in the morning (early part of the day) based on our clocks or watches, we take our lunch break when the sun is high and the clock says noon. Work ends at 5 PM, which is as evening approaches. Doesn’t this mean clocks measure not only days, but the parts of days? Still, no.
Clock measure time intervals. From time immemorial, the most important major periodic event is the day. So when clock manufacturers make watches, they most often calibrate them so the hour hand passes 24 numbers in the same interval of time that it takes the earth to rotate. This is a matter of calibration, not of cause and effect. If the hand of God were to slow the earth, would the clocks slow too? On Joshua’s long day, did clocks stop because the earth did? Within the human body are numerous biological clocks, which exhibit a regularity rivaling a fine timepiece, and if clocks had stopped on Joshua’s long day, then he and his army would immediately have fallen lifeless.
There was an experiment years ago in which a small group were given watches that were deliberately calibrated to run slow, taking an extra hour to come back to their starting point. The group was not told of the bias in their watches, and could not see the sun or stars to compare with. The objective of the study was to see what biological rhythms in the body were finely attuned to a 24 hour day, and would drift out of sync with the doctored watches. But for us, the point is that their watches were measuring time just as real as the ones we use. The actual number of our minutes in each of their displayed hours was a little over 62, so their “hour” was not the same as our “hour”. But their watches which did not respect the earth’s rotation were as faithful to their task as the ones that we have that are calibrated to match the time it takes the earth to rotate. Watches measure what they are calibrated to measure, and that is intervals of time, not the rotation of the earth. If my watch happens to match up with the time this earth takes to turn, then that is very convenient. Until I go to live on Europa. Then I will need to – not measure Europa’s rotation with my watch – but to recalibrate my watch to match the time it takes Europa to rotate.
Just for technical accuracy, some timepieces in fact measure other things than time. We read time on their dials because the thing they are depending on is constant. For example, some clocks may depend on gravity to pull a weight that directly drives a mechanism. In outer space, in the absence of gravity, they would stop. Not because time had stopped, but because the thing that they were really measuring was gone – the pull of gravity. Another example of this – dripping seal bladders. They don’t really measure time, they measure gravity and water viscosity. Other clocks may be based on the flow of a river, which may speed up in a flood or stop in a draught. And the Foucault Pendulum can be considered as one of the few clocks that indeed does what I said clocks don’t do – measure the earths rotation, or in other words - days. (Even that is not as simple as it seems, since a Foucault Pendulum usually takes longer than 24 hours to complete a circuit.)
But the point of this is – a day can mean the time for a rotation of the earth, and that takes an interval of time to complete. Clocks measure intervals, and hopefully the interval the clock is calibrated to measure is the same as the interval in a day. But if that is not true, then the clock is just not measuring days, but it is still measuring time.
Now let’s return to Bob’s scenario. But instead of waiting eons for the valley and mountain clocks to agree once again at noon, let’s wait for just one eon to pass and look at the clocks. For one of them, when it says noon, the sun is directly overhead. But for the other, the sun is near the horizon. After another eon, again the first clock is faithful to the sun, but the other declares noon when the sun is nowhere to be seen, and the moon rules the sky. As we go forth to the time they again agree, we see that one clock has that malady that so many clocks have been cursed with, it is apparently just running a bit slow (or fast).
But one of our starting rules was that these two clocks were synchronized on day one, and both were tested to show that they kept faithful time. In spite of the synchronization, and their identical construction, one is running fast. This is basically what Bob already pointed out in his scenario. But now the question is why?
The God Clock
Bob, for theological reasons, adheres to a universal time standard, perhaps some kind of divine timepiece that might act as a standard for the two clocks we are dealing with. Surely this angelic artifact can tell which is the true time. Bob identifies this timepiece:
Genesis says that God gave us the Sun (and other astronomic bodies) for “seasons, and for days and years.” It turns out that God gave mankind great timekeepers <referring to the sun, moon, and stars> (and less misleading ones than our atomic clocks as interpreted by theorists)! The movements within our solar system give us a more correct understanding of the absolute nature of time than do the ticks of atomic clocks.
This illustrates one quality that I like about Bob – when he puts his foot in his mouth even the ankle and knee are inside.
I will answer this in two ways. First, this idea of the immutability of the heavenly bodies as timekeepers is compromised from Bob’s own post when he says:
… the earth originally orbited the Sun in exactly 360 days …
Since years now have 365 days, then this statement from Bob necessitates some changeableness in the heavenly timepieces. Either years changed in length or days did, or maybe both. And both are measured by reference to the heavenly bodies. I will touch on this 360 day year again a bit later. But now let me go a bit in depth into looking at Bob’s claim that the sun and moon are better timekeepers than atomic clocks. I am going to talk about the measurement of time.
An Uncomfortable Second
I have found that in talking to students who are first undertaking a serious study of science that there are certain questions that make them uncomfortable. Not personal questions, but questions that force them to think deeply about subjects they have always thought they understood perfectly well. I suspect Bob has found the same in theology – asking some questions foundational to an accurate understanding of God elicits a degree of evasion and even offense from those who assumed they trivially knew the answers.
In the case in point, I need to ask – what is a second? Why would such a simple and obvious question cause discomfort? If I as a pretend scientist don’t know what a second is, how dare I time the cooking of a boiled egg, or watch the second hand on the wall clock, to say nothing of using time in science?
If I asked that question of Bob – what is a second – he might hand me his $20 digital wristwatch with a built-in timer button and elapsed time display. Push the button, the timer starts. Push it again, the timer stops. The number on the screen shows the number of seconds (maybe even down to one-hundredth of a second). Pretty cut and dried.
In science we have stopwatches that come in many forms. Some are vastly more accurate than any available on your wrist. In the world of atomic physics, some particles live out their entire existence in a millionth of a second. The hundredth of a second between clicks on your stopwatch would mean ten-thousand generations of these particles would be missed.
This points out why the questions I am asking are seldom considered by the public. For day-to-day needs the wall clock or wrist watch accuracy for measuring time is fine. Only in select realms of science is the need for hyper-exquisite accuracy needed. But for those scientists in that rarefied realm, the exact length of a second is of paramount importance.
Let there be lights in the firmament of the heaven … for days, and years
I can show you hundreds of books and articles that say there are 86,400 seconds in a day. And they are (kind of) wrong. Remember earlier I said a day was the time from sunrise to sunrise? But a day can also be defined as 86,400 seconds. So a reasonable answer as to what a second is would be to say it is 1/86,400th of a day. For millennia, that answer would have seemed to provide a clear reference standard. But a couple hundred years ago, not long after Newton presented his Laws of Motion and Gravity, some scientists were looking at how Newton’s Laws could explain the motions of stars. For several thousand years prior, a deep and widespread belief in astrology had been the driving incentive for observers of the heavens to make voluminous and quite accurate records of the stars.
Looking at these records, and then looking at the motions of the earth, moon, sun, and stars via Newton showed something small, but significant was amiss. Solar eclipses, where the moon intercedes between us and the sun are dramatic, rare, and prime candidates for ancient scribes to keep records on. The “rare” is the important word here. Why are they so rare?
Look at a Lunar eclipse, where the moon passes through the earth’s shadow. Nearly anyone on the moon-facing side of the earth, if his view is not obscured by clouds, can look up in the sky and watch the drama as one side of the brilliant full moon starts to darken, then a curved shadow progressively darkens the lunar disk, and finally the moon is hardly seen at all, appearing more as dull dark apparition than the beautiful white majesty it was only minutes earlier. Then the earth’s shadow slowly relinquishes its command over the light of the moon, and as it slides off the moon the moon’s glory is returned.
But the geometry of a solar eclipse is much different. Instead of the big earth easily casting it’s shadow over the much smaller moon, now the moon is charged with blocking the view of the (relatively speaking) monstrous sun. If you are privileged to see a total eclipse of the sun, at that moment you are effectively at the apex of a cone, with the disk of the moon exactly spanning the cone just a little ways up from the apex, and the sun also spanning the cone, but far away at the top where it is broadest. Now at that moment, what does your neighbor, only a few miles distant see? He is not at the apex of the cone. Even though he is close the moon is only partially blocking the sun.
As the moon moves in front of the sun, the apex of the cone where totality is complete will trace a narrow line only a few miles wide across the ground. If that track passes over you, you see totality for a brief time. If that track only passes near you, the sun is dimmed, but never totally blocked. But for the vast majority of people on the sunlit side of the earth, the apex of that cone traces a path that comes nowhere near them, and there isn’t even a partial eclipse.
This means that the relative motion and positions of the sun and moon and earth can be inferred with surprisingly accuracy by just knowing what cities or monasteries or observers were blessed with the sight of a total solar eclipse on a given day in history. Since the earth is rotating at 1000 miles per hour (at the equator), even a slight difference in time would mean the path of totality in a solar eclipse would be moved many miles.
And this was what was observed. By applying Newton’s Laws with the clock running backward, it was possible to predict with great accuracy where ancient solar eclipses should have been seen. But in the ancient records they weren’t seen when they were supposed to have been seen, at least in the predicted locations. Oh, the eclipses were seen on schedule, but by cities hundreds of miles from the cities that should have seen them.
Agatha Christie on the Moon
Solving this astronomical mystery was an effort that spanned literally hundreds of years, and is a fascinating detective story of obscure clues and false leads and even intentional deceit. The story is much too long to recount here. Even today, with our “advanced” understanding of science, this saga is still playing out. The major culprits in this theft of time have been pretty conclusively identified, but there appear yet to be some co-conspirators that are very hard to catch and understand.
But this much is no longer in dispute. The earth is slowing its daily rotation. The major culprit that I mention above is called Mr. Tidal Interaction. It is a result of the tides reaching their maximum height a little bit after the moon is overhead. This results in a small off-center gravitational pull between the moon and the high tides, with the result that the moon is gaining angular momentum from the earth. The moon’s gain is the earth’s loss (as dictated by one of the most fundamental laws of physics – the Law of Conservation of angular momentum).
This slowing of the earth’s spin is very slow, but over centuries it is significant. And for our purposes, it shows that saying that a second is 1/86,400th of an earth rotational day just doesn’t cut it. Today is microscopically, but measurably longer than an earth rotational day one hundred years ago. So a second based on 1/86,400th of a day a century ago would be microscopically shorter than a day based on 1/86,400th of today. What to do? Pull the pin first.
Neglecting to Pull the Pin Before Throwing the Grenade
When Bob proposes the heavenly bodies as the ideal time references, he parts company with at least one significant creationist argument. In several creationist places can be found the claim that the earth-moon system cannot be more than 1.5 billion years old, definitely less than the 4.5 billion years claimed by science. This claim is dependent on the fact that the earth’s rotation is being slowed by transferring angular momentum to the moon. A simplistic (and that is the key – too simplistic) analysis shows that going back in time, the moon would be sitting on the earth. A necessary consequence of this claim is a very significant slowing of the earth’s rotation, meaning it has been anything but a good clock since day one.
It Has Been a Perfect Day
No problem, just pick one certain day, and define that one to be the “perfect day”. By definition, that day was exactly, precisely, dead on, 86,400 seconds long. And that is what happened. I think it was January 1st of 1900 (or some such day) that was picked. What it means for us today is, considering the slowing of the earth’s rotation since 1900, today will have more than 86,400 seconds in it. (This is a tremendously simplified version, since there are a myriad of minor short-term effects on earth’s spin – arctic ice buildup and melt, geologic processes, etc).
How to Measure Perfection
A secondary problem is calibration. If I have a clock that I need to use as reference source, how can I verify that it is doing its job well? I must compare it with another clock that is believed to be correct. But that clock likewise needs to be calibrated, by comparison to an even more reliable clock. Ultimately we end up at the clock that serves as the ultimate source, sort of the “Adam” of time, to which all time standards trace their genealogy.
Bob would have us take motion of the sun, moon and stars as the perfect references. But accurate measurements centuries ago showed that these motions are not constant, and the imperfections in this timing is large enough that science has found numerous more faithful clocks. Bob should remember that one of the achievements of Kepler was the recognition that planets (including the earth and moon) have orbits that are elliptical, not circular. And another of Kepler’s observations was that orbiting bodies trace out equal areas in equal times. Meaning what? Meaning that they go slow when far from the sun (or when the moon is far from the earth). And then they speed up as they swing close to their capturing body. Not only that, but all the bodies in the solar system pull on each other. This means the simple ellipses that Kepler described are only first approximations, and the final orbital solutions are so difficult that to this day they have not been solved in any simple way even close to the ellipses of Kepler.
I mentioned picking a “perfect day” as a standard time reference. Agreeing on a specific day to reference as the standard only works up to a degree. On that fortuitous day, there were no perfect clocks that could record the exact moment that day had completed, and thence forth serve as perfect time references. The factors that have changed the length of a day since are known well enough to confidently calibrate clocks to exquisite accuracy. But ultimately, the uncertainties in these factors act as barriers to unlimited precision. Science was then forced to search for an even more precisely defined time standard. With the understandings that arose out of the new field of quantum mechanics, it was realized that maybe it was time to turn away from the time-honored tradition of referring all time to the rotation of the earth. There are atomic processes that, for well-established practical and theoretical reasons, can be used as faithful time keepers with far less uncertainty than the earth’s rotation. These time references have the added advantage of being portable, at least in theory. In reality the ultimate timekeepers today are maintained by the National Bureau of Standards under conditions of care and keeping that would be the envy of the most pampered royalty. But superbly accurate copies of these time references can be created in many laboratories. In a futuristic scenario it makes far more sense for a distant spaceship to reference time to an accurate atomic process that is onboard as opposed to the less well understood rotation time of a distant planetary body some hundred years ago.
300 Cuckoo Clocks
In a later post in this thread Bob poses the following question:
Johnny, then what do we conclude from an antique clock shop with 300 ticking clocks on it's shelves, all keeping slightly different time?
If we look closely enough, this is exactly what we would see in any antique clock shop. No two mechanical clocks keep identical time. If we have to decide which is right, and are not permitted to compare with an external calibration source, then we would repeat what was actually done historically with time standards – we would pick the one that held our highest confidence and define the passage of time with it being the reference source.
My Loss is Your Gain
Even with most perfect atomic clocks, you sometimes see statements like “These clocks lose only one second in a billion years”. What??? If someone says the primary reference clock is losing one second after a period of time, they must be comparing it to something even more accurate. And if there is something more accurate, then that something should BE the primary reference. Indeed, when two identical primary reference clocks are compared with each other, one may lag the other by one second after a billion years. But is it the lagging one that is wrong, or is the faster one running too fast?
It makes no sense to measure time beyond the accuracy of your best time piece. I might feel the faster clock is true, and you prefer the slower one. Neither has the upper hand. There is no higher accuracy clock to refer to. Scientists are always watching for phenomena that can provide even more accurate reference frames than the ones now chosen. Being the King of Bunker’s Time Hill is a precarious job, whatever has that honor today will be unceremoniously dethroned the moment a more accurate clock is found.
Experience is not the Best Teacher
The uniform passage of time is an empirical concept. What does that mean? It means that over the eon’s of man’s dealing with time, it has always seemed to pass at a constant rate. I am not speaking of the passage as measured by man’s consciousness, since during deep sleep or under anesthesia or such time slips by much more rapidly for the slumberer. By when physical devices – starting with primitive clocks – were put in play, they gave indications that time passed at the same rate without regard to human consciousness. As many ideas do, the evidence that this passage of time was constant subconsciously assumed the role of a physical law. It had been tested by a billion dripping water hides and burning ropes and pendulums and balance wheels and hundreds of other types of clocks. It was clear to all that the rate of flow of time was not something that changed.
Attacking the Messenger
It was this fundamental gut feeling that had stood unchallenged for so long that evoked such a reaction to Einstein’s work. Over the decades following Einstein’s’ pioneering efforts two opposing things happened. One is that his ideas came under intense practical and theoretical scrutiny. The other is that they came under intense ridicule. Now, a century later, the evidentiary and theoretical support for the correctness of Einstein’s ideas are well enough founded that, with the exception of the always-expected detractors, it has moved into a position of honor in the scientific community. Meantime, the detractors have found less and less technical pretense for their nay-saying, and as is evident here, have found their primary impetus not in scientific challenges to relativity, but in theological or even personal dislike for its conclusions.
Denver – the Model City
Part of what Einstein said was that our millennia-long observations of the constancy of the flow of time were based on data in which the changes were far too small to detect. If Bob had been born and raised in Denver, and never had ventured beyond it’s orders nor been exposed to ideas and climate and cultures from the neighboring states, to say nothing of the neighboring countries, he might feel well justified in thinking that Denver was an archetype for the world. When finally he ventured out of its boundaries, no matter how uncomfortable it might make him feel, he would be faced with the realization that his assumptions were based on the provincial nature of his upbringing, and not an understanding of the real world. He might find Denver is the exception, not the rule.
For science, to step outside of the borders where time is always a constantly flowing commodity has required that it move to speeds unattainable until atomic physics came along, or to sensitivity in measurements unthinkable just a few decades ago.
So those convenient discrete lengths of time called seconds and days that we are so comfortable with are not the absolutely defined measures we sometimes think of them as. At their most fundamental level, they are just time slices as measured by the most consistent time sources we have found. Our accuracy in measuring seconds is limited by the accuracy of the reference source, and to pretend that we can measure higher accuracy than that is disingenuous. “A good man always knows his limitations” (Clint Eastwood in Dirty Harry). And not all roads lead to Denver.
Rodents and their days and their geometries
Here I am going to break from my dialogue to comment on something that Bob said that has direct relevance to what I covered above. Bob said:
Well, since the earth originally orbited the Sun in exactly 360 days, the ancients divided circles into 360 degrees …
The rate at which the earth’s rotation is slowing is known to a fair degree of accuracy. As mentioned above, there are uncertainties in how constant this rate has been over time, but I have not seen anything to suggest that the rate has been dramatically different in the (geologically) recent past. Currently this slowdown of the earth’s rotation amounts to each day being less than 2/1000 of a second longer than the same day was a century earlier. Even though the slowdown of the earth is not linear (meaning the slowdown is not always 2/1000 of a second per day per century), over periods of even a few million years the error in assuming it is linear is not large.
So, to go from the current 365 day year (approximately) to an ancient 360 day year, each ancient day must have been 360/365 as long as today. That means each day needs to have 1100 seconds cut out of it. At a rate of less than 2/1000 of a second per century, that means we are looking back to a time over 600,000 centuries ago, or about the time science (real science) says the dinosaurs got snuffed by an errant asteroid. At that time the “ancients” (meaning our ancestors?) that Bob refers to were probably much like small rodents today. I agree with the evolutionary timeline this involves, but I have never known rodents had a level of intelligence capable of dividing circle into degrees. Thanks Bob, I learn something new every day.
Not Unlike a Politician
This case of the Bob’s left hand (earth is a God’s time source for us) not knowing what his right hand (lengths of days and/or years are changing) does have the ring of what a politician might say. This is not without precedent from Bob, however. Long prior to this thread, but still on the subject of astronomical observations, Bob once declared:
… the belt of Orion, and the Pleiades, and of all the constellations, about 80-some constellations up there, that are ancient, scientists today, astronomers tell us only 2 of them are gravitationally bound. And I know you know what that means, but let me explain it to any public school teachers listening. Just like the earth is gravitationally bound to the sun, we are pulling on one another, so the earth can’t get away.
Well the constellations, 2 of the 80-some constellations are gravitationally bound – the Pleiades, and the belt of Orion. Where those stars are locked – they are holding one another in place. And Job 38:31, God asks this question to prove how great he is, and how small man is, God says: “Can you bind the cluster of the Pleiades, or loose the belt of Orion?”
What about a statement! Talk about - only 2 out of 80 constellations are gravitationally bound, and here is the oldest book in Bible, surely they couldn’t have known that by any of man’s abilities, but God created the universe, and our galaxy, and he knows the Pleiades, and Orion’s belt, because he made it, and he knew that of all the constellations, those were the two that are gravitationally bound. So he says can you bind the cluster of the Pleiades, or loose the belt of Orion? (My emphasis)
Notice the amazement Bob expresses at the wisdom of the writer of Job at somehow knowing anciently that the Pleides and Orion’s Belt are gravitationally bound. The Pleides – yeah, I’ll buy that. But Orion? Hmmm. A bit of searching in astronomical databases shows something most interesting. The stars in Orion’s belt are immense distances apart, far too distant for gravity to have any significance at all between them. Their alignment from our viewpoint is coincidental, not unlike looking end-on at a row of street lights. They look to be next to each other, yet each is far down the street from the one it is next to. So – a mistake. Yeah. A politician’s mistake. For a couple of years later this is what Bob said about the same thing:
…in the book of Job, God talks to him, and reveals Himself as God planting astronomy evidence then into ancient history which has become especially compelling today, nearly 4,000 years later. In the dialogue of this ancient book, God asked Job:
“Can you bind the cluster of the Pleiades, or loose the belt of Orion?” Job 38:31
Not until millennia later could modern astrophysicists confirm the fascinating knowledge presented by this verse, which was designed to humble Job before the Creator. For the stars of the Pleiades are gravitationally bound together, “bind[ing] the cluster,” and the stars of Orion’s belt are speeding away from each other, “loose[ning] the belt.” Before we had light spectrometers, radio-telescopes, or the orbiting Hubble, we had the Bible. And in its oldest book, back when men had no advanced technology to interpret data in starlight, the Bible quotes God somehow accurately stating that the stars of the Pleiades are bound together, as they are, gravitationally bound, and that the stars of Orion’s belt are loosed, as they are moving apart and eventually, would completely undo “the belt” from Earth’s perspective. What are the possibilities that of all the stars visible to the naked eye, of all the ancient constellations, of all the infinite number of ways to describe a picture in the sky, that Job would make an astonishingly accurate scientific statement? (My emphasis)
What? First he expresses wonder at the writer of Job knowing exactly which 2 constellations are gravitationally bound, and then turns around and expresses even more wonder at the writer knowing that one of them is anything but gravitationally bound – in fact it is flying apart. I too am amazed. Politicians - take a lesson. To Bob it doesn’t matter what the writer of Job says about Orion – just quote back what you think Job meant and express amazement. Next year, different audience - try the opposite conclusion, but be sure to once again express amazement.
What’s Wrong with This Blasted Clock?
Bob is aware that the predicted effect of gravity on time (or at least the measurement of time by some clocks) has been measured. The effect was large enough that it was clearly not just a statistical fluctuation in the data. The effect is real, measurable, and reproducible. And, I might add, with a consistency that makes the regularity of the earth’s spin look like a drunken sailor.
Let’s look at that. Two clocks are built, identical in all-important respects, and found to agree to a high accuracy. One is moved to a high place, and it begins to drift in time from its sibling. For illustration purposes I am going to pretend these clocks are of a type familiar to all of us – pendulum clocks.
For a pendulum clock maybe the lesser gravity has affected the movement of the pendulum. Well, if that is true, then we can use a different kind of clock. Instead of a pendulum clock we can use one with a balance wheel as its basic mechanism, like watches used before the advent of digital watches. Of course here if the lesser gravity microscopically changed the friction between the bushings and the axles upon which the geared wheels rotate, we may again see the clocks drift apart. But there would be no reason to expect that the alteration in time due to a lesser gravity on a pendulum would be the same as the change in friction of bushings. Also, the balance-wheel timepiece can be rotated 90 degrees so that the change in gravity is not in a direction that will change the force between the axle and the bushing.
We can also turn to a watch using a crystal oscillator as its time source. With its lack of mechanical moving parts, we can no longer look to the interplay of mechanical parts to explain the observed time shift.
In fact, my allusions to pendulum clocks and to balance wheels clocks are only illustrative. The magnitude of the time shift we have measured in experiments near the surface of the earth is so small that even a microscopic mechanical change would swamp the looked-for time shift. The point is, if we perform the same experiment with clocks that depend on fundamentally different processes, then there is no expectation that gravity would cause them to “malfunction” to the same degree. It is independent but corroborating testimonies from scientific “witnesses” that have no acquaintance with each other.
From Idea to Iron
Case in point, early on there were two specific experiments. One (Hafele-Keating) relied on cesium-beam atomic clocks, while the other (Pound-Rebka) relied on properties of iron. Right now there is an on-going orbital test called Gravity-Probe B that depends on another time source, the response of gyroscopes.
The specific scenario Bob outlined depends on a gravitational gradient. But the more fundamental question of time not being constant for everyone is much simpler. The variability of time was first proposed in 1905 when Einstein brought forth his Special Theory of Relativity. Special Relativity, and specifically the portion of it that deals with time changing, is a Theory that has been so well verified that it is a standard tool employed throughout the world of physics. Every particle accelerator in the world would be a pile of useless junk if Special Relativity were wrong.
This independence of the time dilation effect on the type of clock that is used has fundamental implications. Not just that coincidentally every clock becomes inaccurate in the same way, but in a much more basic way. Most of the types of clocks that have actually been employed in time dilation tests rely directly on very elementary physical properties at the atomic level. The field of Quantum Mechanics is indispensable in even dreaming up what clocks are accurate enough to do these tests. This means that the most fundamental Laws of Physics respect the predictions of time dilation.
Marching with Mach
So we now invoke an idea from Ernst Mach, a great physicist that heavily influenced Einstein’s thinking. Here’s the idea – if every clock we can possibly build relies on the fundamental laws of physics, and when tested those laws show time dilation, then what does it mean to say the clocks are wrong? A clock is wrong when it is placed next to a clock of superior timekeeping ability, and with which it disagrees. Every test of this idea ultimately comes back to one physical clock being compared with another. But if every physical clock obeys fundamental physics, and the clocks that have been shown to most clearly show time dilation rely on fundamental physics processes, then what is left? Does it make more sense to say that time is constant, but no clock that can ever be built will show it is not, or to say that time is the thing that has changed? Is the lone soldier who puts forth his right foot the only one in step while marching, when each of the others has his left foot forward?
Being Blessed by Weakness
Certainly time has seemed to flow at a constant rate through all of human history. And there was initially no reason to suspect that a change in gravity would have any effect on the passage of time. People had climbed from sea level to mountaintops for many generations, and never noticed any difference in time.
But modern physics has some important insights into the gravity issue. In daily life, especially prior to the advent of industrial production of electricity, gravity was the major force that people dealt with. Even today we feel the effects of gravity almost constantly, whether subconsciously while walking or sitting, or consciously as our nose nears the floor after we trip. We are benefited from electricity, but we don’t perceive of it being the constant that gravity is.
And that is well. For, in spite of its perpetual influence on us, gravity is weak. I mean puny, lazy, feeble weak.
One of the blessings of nature is that the sum of electric charge, as in the negative electrons and the positive protons that comprise atoms in our world, balances out to almost perfectly zero. Only a slight upset in that charge and we get lightning bolts flashing between ground and clouds.
What would happen if this electric charge were not so exquisitely balanced? Assume in your body and in the earth all the protons changed into antiprotons so they had the same charge as the electrons, and by some way the atoms still held together. Now you are 150 pounds of pure negative charge, and the earth likewise is negatively charged. Like charges repel. Gravity attracts. So which wins out, the 150 pounds of gravitational attraction pulling you down, or the repulsion of the negative earth on your negative body?
As I said above, gravity is weak. So weak that we need to add a bit of weight for you to hold in your arms to increase the gravity so you aren’t repelled off the earth by the negative charge. This new mass will need to be electrically neutral, so it doesn’t aggravate the charge problem, and only provides weight. How much added weight do you need? An additional 150 pounds won’t be enough. An additional 1500 pounds is insufficient. In fact, to avoid counting pounds, let’s assume you are holding up a platform of neutrally charged people, each weighing the same as you. If you were to put every person on earth on that platform, you are still going to be ejected by the charge repulsion. To go to the final answer, you would need to be holding up a billion billion billion billion people. That is more than a hundred million billon billion times as many people as are on the earth. If every star in the known universe had ten planets, and each planet was as populous as the earth, you would still be short of bodies to help you stay down. Of the forces known to physics, gravity is so puny as to be ignorable in most experiments dealing with other fundamental forces. This immense disparity between the strength of gravity and other forces is part of the difficulty in coming up with a common theory that encompasses all forces.
For us, this points out something. Climbing from a valley floor to a mountain top means the gravity is being lessened. But even in the valley floor, gravity is only an inconceivably small force as viewed from the other forces encountered in nature. Even a trip into outer space where gravity may be completely ignored is tantamount to taking a penny out of the national debt. So it is not surprising that no effect on time was ever noticed in the climbs from valley floor to mountain top.
And be thankful that it is gravity that binds you to this round rock called earth. If it were pure electric charge, going down stairs and forgetting there is one more step to take would not jar your teeth as you fall that unexpected 6 inches. The impact would turn even the bones in your body into a one-atom thick smear covering the floor.
The Testimony of IBM and Monkeys
The explosion in technology we have seen over the past few decades is not an accident. It is a very real proof that the underlying laws that science has recognized in nature are real and valid. If given an array of advanced electronic components a group of monkeys would not randomly connect them into the precise arrangement that we call a computer. Similarly, the Laws which predict time dilation are not just good guesses. They are the end result of some very deep mathematics that leads to predicting the effects actually observed. To dismiss these predictions as some unexplained anomaly that plagues every clock used as a test piece is to find IBM is a front for a group of chimpanzees.
So, in summary
- Time is measured by clocks. If every clock, when placed in a new environment ticks at the same new rate, to declare that the clocks are in error is an empty definition. It would be equally accurate to say that in that new environment time should flow one hundred times as fast, but I cannot produce a single clock that reads out that faster flow of time. Then each of us might with equal meaning choose whatever rate we want to declare time runs at in that new environment. But the real clocks will give little heed to our squabbling, any more than the one left on the valley floor would if we tried to control it’s measurement of time by the force of argument.
- There is an impressive correlation between the intricate mathematical and physical derivations of time dilation and the verification of that line of logic. To declare that the line of logic is flawed, and that the effect is actually some fundamental change in the physical or electronic mechanisms as opposed to a change in time itself presumes an amazing coincidence. It would be like declaring that aeronautical engineers were fundamentally wrong on how aircraft fly, and the success of their predictions is just a coincidental outfall of the real mechanism – that the earth and moving aircraft have a natural antipathy for each other, and that opposition keeps them in flight.
- If every clock changes its behavior in the same way and to the same degree in a new situation, and that change grates on our intuition, do we allow intuition to preempt evidence? Has nature ever changed her rules to accommodate the whims of fickle man?
- If every clock changes its behavior in the same way and to the same degree in a new situation, does it make sense to declare that the only thing unchanged is time itself, and no clock can ever measure that time correctly in that situation? Time then becomes an empty concept no longer amenable to measurement in our laboratories.
- If a clock on a mountaintop measures time differently than on a valley floor, and time is an absolute invariant, is it possible that the “true” time is the one in the hermit’s cabin on his high peak? What, other than popular vote, is to decide that true time is that measured at sea level? Maybe true time is that in outer space, and all earthbound clocks are degenerate since Adam’s fall. Or is true time that found in the particle accelerators where lives are extended to multiples of their stationary allotments?
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Banging into Time
25 years ago Stephen Hawking showed that in the big bang not only was space “created”, but so was time. We often hear of “space-time”, which is just a mathematical construct allowing us to study the way space and time relate to each other. Ever since the ancient Greeks we have known much of the geometry that relates the 3 dimensions we deal with daily – length, width, and height. Each of these 3 “spatial dimensions” has a common mathematical relationship to the others. If I need to know the distance between two points, I can use the Pythagorean Theorem to find the result of considering all three distances at the same time. In a geometrical sense, I can start at any point in the three dimensional universe and go to any other point.
When we follow Einstein’s lead and wrap this “time” dimension in with the other 3 dimensions, we have to be a little careful. Time can be treated very similar to, but not identical with, the spatial dimensions. There is a mathematical relationship very much like the Pythagorean Theorem that ties time to space, but only the time term has an important negative sign associated with it. This sign has important implications for the geometry of “space-time”. Time “flows” past us, in a sense like distance might flow past us if we were on a train that we had no control over. But in this 4-dimensional world, we no longer can, even in theory, reach any point within it.
There is one interesting constant in our lives in space-time. Our “speed” through space time is constant. If you do the math, you will find that as you pick up speed in any of the spatial dimensions, your travel through time slows exactly enough that the diagonal in 4-space between your starting position and your ending position lengthens at exactly the same rate as it would have had you not moved at all, and your only progress was the natural flow of time. Moving the increasing length of this diagonal out of a purely time realm into a substantially spatial realm means the flow of time is greatly slowed. This is the trick that is routinely employed in particle accelerators to extend the lives of short-lived particles. Make it move fast, and its ageing will slow.
If time was as much a product of the big bang as was space, then what does it mean to speak of “before the big bang?” The dime-store books popularizing the big bang often wax eloquent about cyclic universes, and the relevance of the Laws of Thermodynamics on the cycles, and on and on. To separate the purely speculative from what is known, ask if they can back their ideas with math and physics. Then again, maybe not. The label of good physics gets stamped on some pretty un-physics ideas. Best way to tell – go get a PhD in string theory. Second best – ask me. Trust me.
Where does the creation of time in the big bang fit in with God? I don’t know. I have no discomfort with admitting that science has limitations. If God exists “outside of time”, fine. I have no idea what that means other than as a way to claim that God doesn’t get saddled with the limitations time places on us. If time flows for God as for us, fine. Can you show that is true, or is that likewise just a statement that is constructed to fit what you want your God to be like?
Shermer Vindicated
Bob says:
Genesis says that God gave us the Sun (and other astronomic bodies) for “seasons, and for days and years.”
But continuing:
And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
The natural assumption is that the “greater light” means the sun, and the “lesser light” is the moon. But the moon is not a light. Or at least if it is a light, then so is the hunk of rock on my desk. The light from both is just reflected from other sources. And the moon is not unlike man, giving little heed to the divine charge given it. It spends as much time in the sky during the day as at night, and is AWOL from its job of ruling the night about 50% of the time.
The Theology of Quarterbacking
The best way for me to address the theological part of Bob’s question is this:
Your religion ___________________________ (fill in the blank)
The impact that the flow of time being non-constant on my faith is:
__________________________________ (fill in the blank).
Contrary to the parody voiced by some, science is not religion. Looking at the fill-in-the-blanks above we see this clearly. In the religion field above, I find Catholics, Lutherans, Hindu’s Mormons, and Baptists. Each has his own unique statement of impact in the last field. Yet I have often walked in the laboratory and stood shoulder to shoulder with Catholics, Lutherans, Hindu’s Mormons, and Baptists. And in that laboratory, I found not one iota of difference in the scientific answers we came up with that correlated to their religion.
Mother Nature is a horrible team player. We huddle and decide who will run left and who will catch the pass and what part Mother Nature is to do. Then when we execute the play Mother Nature grabs the ball and makes an end run. We all scream at her that her job was a defensive lineman. Next play, she does her thing again. Didn’t take much playing to realize that Mother Nature is a superb player, but you play by her rules or she will run right over you. She isn’t going to ask what your religious traditions say about how she should act. Her rulebook is the same for every game – it is called Science. We are still figuring some of it out, and Mother Nature sometimes surprises us with a new trick play. But on those things that we pretty well understand, she is constant, if not accommodating to our wishes.
I hate her. And love her. Forgive me, for now it is time to plan a new play and see what part Mother Nature assigns to herself in the play. Joe Q. Muslim is our best left tackle, atheist Todd is amazing at interceptions, and fundamentalist Pete is a heck of a quarterback. But I just hope we don’t all find ourselves in a pile watching Mother Nature running with the ball all by herself – towards the wrong goalposts. Every time this happens we run down and scream at Mother Nature for her blithering stupidity, and then she points at some detail in the rules that missed all of us. Oh the humiliation of being shown wrong every time. The Catholics hate it, the Baptists do too, even the Muslim mutters under his breath. Only the atheist is unperturbed. But at least our game improves.
