Time Doesn't Exist

Meshula writes "An interesting article suggesting that time is an illusion of perception has appeared at New Scientist. "...quantum mechanics supports it. In 1929, the British physicist Nevill Mott and Werner Heisenberg from Germany explained how alpha particles, emitted by radioactive nuclei, form straight tracks in cloud chambers. Mott pointed out that, quantum mechanically, the emitted alpha particle is a spherical wave which slowly leaks out of the nucleus. It is difficult to picture how it is that an outgoing spherical wave can produce a straight line," he argued. We think intuitively that it should ionise atoms at random throughout space. Mott noted that we think this way because we imagine that quantum processes take place in ordinary three-dimensional space. In fact, the possible configurations of the alpha particle and the particles in the detecting chamber must be regarded as the points of a hugely multidimensional configuration space, a miniature Platonia, with the position of the radioactive nucleus playing the role of Alpha. " It's worth a read. "

Comments

Time

[Signal 11]

Assuming time doesn't exist, why is it that I always get to work late? Is it that I'm already at work and exist at home simultaniously (and thus I really am not late)? If so, they're not paying me enough!!

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Slashdot needs a science editor

[The Iconoclast]

Meaning no disrespect to Hemos, CmdrTaco, etc., etc., Slashdot realy needs a "science editor." Someone with an appreciable knowledge of science. This article is quite a heap of crap, from a scientific methedology standpoint (to say nothing of the lousy "physics" involved).

Anyway, most of the time, the /. editors put decent ideas and stories up, but from time to time, things like this get through. This story is filled with misinterpretations and omissions of quantum and general relativisitc theory.

One does not have to know evrything there is to know about all fields of science to determine what is valid, but one needs a basic understanding of each fields underlying principles as well as the use of scientific reasoning. These skills and knowledge one can learn from a decent undergraduate eduaction in the "hard sciences" (Physics, Chemistry, Biology, Astronomy, etc.). An undergradute eduaction in these fields is not the ONLY to recieve this knowledge, either. They are just the ones classically recognized as providing a decent platform onto which one can learn about other types of science. The anaylitical skills learned from these fields allow one to anaylize other's scientific arguments based upon their scientific merit and reasoning.

I would like to propose that, in particular, Physics gives an excellent background on other sciences as well as the needed training in scientific reasoning. Hey a guy can have a small bias can't he? :-) Anyway, the concepts learned in an undergraduate physics program have applications in almost every scientific and engineering field (uh oh, I said the dreaded E-word :-) One learns about the scientific method, Newtonian Mechanics, Thermodynamics and energy, Quantum Mechanics, Electricity and Magnatisim, Materials Physics, and Relativity. This stuff won't tell you everything there is to know about Biology, Chemical Engineering, Computer Science, or whatever, but it does get you quite a bit along the way.

I am sure other disciplines teach the analytical thought processes and most of the topics I mentioned. However, physics is the study of how everything works, so it is kind of broad :-)

Anyway, I'm sorry if I sound like a snot. I'm not trying to berate other sciences. I actually think that the skills any science teaches are essential in being able to discern what is valid and what is not, at least from a scientific viewpoint.

As you can probably tell, I am a physicist. I am at the Depatment of Physics at Case Western Reserve University. Email me if you want. It should be easy enough to figure out my real address. I'll get off my soapbox now :-).

This is silly

[jd]

Let's take the following Greek puzzle: If someone fires an arrow at you, and you blink at a given rate, then the arrow travels a finite distance between blinks. The faster you blink, the shorter the distance. If you blink fast enough, the arrow remains stationary.

Why doesn't this work? Simple. This is simply a misunderstanding of Calculus. Mind you, as calculus hadn't been invented then, they can be forgiven for misunderstanding it. As dt approaches zero, dx/dt approaches the true rate of change at -that point-. It's an instantaneous rate of change, so you don't see the effect of it, for that instant, but it's still non-zero, so an effect will occur.

How does this apply here? Here, the reverse has happened. This guy is looking at the INTEGRAL of time, and confusing that with time itself. If you take a line, and integrate it, you will get an area. An area isn't a line, and does not visibly consist of lines, but a simple differentiation will show those lines must exist.

His argument, concerning straight tracks, are this kind of error. He's looking for the integral of a probabalistic wave (as he's looking over a period of time), but he's getting the raw, collapsed wave instead. If you look in the wrong places, you are bound to not find what you expect.

IMHO, this is very poor science. Any school-age kid who's done maths has done calculus, and knows this very simple pitfall. There is NO excuse for it.

Re:This is silly

[ElrondHubbard]

ISTM that confusion like this arises because people confuse real space with phase space. The alpha particle in the bubble chamber leaves a linear track in real space (i.e. the space that we perceive), even though it's "really" an expanding spherical wave in phase space. What the guy is talking about in this article is basically viewing the entire universe not as an entity that unfolds linearly in time, but holistically, as an enormous polydimensional phase space. What we perceive as time and history results because different parts of the phase space have higher probabilities than others, and our brains construct our perceptions by stringing together, for lack of a better word, "samples" of congruent areas of this space.

The part that I find really interesting is the Alpha point, where by definition all particles occupy the same point. This corresponds eerily well with the Big Bang. The idea that the "history" of the universe is just the distance, in phase space, between us and the Alpha point, is an elegant one. I like this theory.

Impact on common jokes

[GnomeAttic]

This "time doesn't exist" thing really puts a damper on a very large and hilarious group of jokes. For example, "What time is it when an elephant sits on your watch? Time to get a new watch!" Will now have to be updated to "What time is it when an elephant sits on your watch? An interesting article suggesting that time is an illusion of perception has appeared at New Scientist...". I suggest that , as mature adults, we squelch this discovery for the good of all mankind, so our children and our children's children can enjoy this diverse category of jokes.

Article explanation and rebuttal

[Ted V]

Here's a brief explanation of the article:

Consider the set of all possible configurations of all particles in the universe. (He names this set Platonia.) Arrange the set so that configurations which are similar are close to each other. In other words, the configuration where I've just gotten out of my chair is close to the configuration where I'm about to get out of my chair, but they're both really far from the configuration where I'm on an airplane flying to Bombay.

He then defines the "arrows" of time as a straight "track" traced between different configurations. Each configuration contains data which has records of "the past"-- other configurations on the same track. Essentially he's changed the definition of the Universe. What we consider "the universe" is a single element of the set he names Platonia. But he names Platonia the universe-- the set of all possible particle configurations.

Let me use his arguments to prove that distance doesn't exist. "Consider what we think of as points on the real line. The point 1 and the point 4 have a distance of three. But there's really an infinite number of points, and they're all connected. I will define the real line R as a point. Distance has no meaning to the real line so distance must not exist! What we think of as distance is really just the separation between two different instantiations of our point R." Technically stated this is true. He's redefining terms in such a way that they're no longer meaningful.

On the bright side, if he could get from "Time doesn't exist" to "consider a set that contains the concept of time", he might be able to theorize something useful.

I'm going to comment on his credentials in a later post...

-Ted

Re:Can you expand on this?

[jd]

Ok, my reasoning is thus:

When you look at something over a period of time, you are effectively performing an integration with respect to time. (In fact, this is true of all experimental science. There is no such thing as an instantaneous observation.)

However, the integral of time is, clearly, not going to be the same as time itself, the same way that the area under a curve is not the curve. The two are related, through the logic given by Calculus, but are otherwise completely distinct.

QM adds some further complications, here. The act of observing something affects the observed. As you are observing over time, rather than instantaneously, you are going to have an impact that is also over time, not simply instantaneous. This needs to be taken into consideration, when looking at behaviours, and I honestly didn't see that.

In quantum mechanics, you have a further complication. Quantum theory talks about numerous probability waves, all of which overlap. When you describe an object in QM, you describe ALL possible behaviours and outomes. However, when you perform an observation, only one of those is ever observed. One solution to this has been to say that the wave collapses in =this= universe, but that there are as many universes as possible states. The QM definition is thus the integral across all possible universes.

However, the same logic must apply. The integral is not the same as the original function. Here, the model is the integral, and what you observe is the original, which is the reverse of the situation above.

In summary, when you observe an object, you observe it as an integral over time, not instantaneously, and you observe it in one universe, not the integral over all possible worlds.

I believe the article confuses the instantaneous with the integral over time, and one universe with the integral over all possible universes. When handling data, it's very easy to slip up and compare data of the same type but the wrong order. It's not like oranges and apples, where you can see the difference.

Author's Credentials

[Ted V]

This article has all the ear marks of a crack pot theoretical physicist whom no one listens to.

The author of this article, Julian Barbour is an independent theoretical physicist who lives near Oxford, UK.

First, notice how he's not actually working at any university, but cites that he "lives near Oxford" as if that makes him smarter. He also does NOT state what kind of degree he has and where it's from. (Not that degrees make one smart, but when the rest of the article is suspect, the degree is too.)

Consider this paragraph:

The notion of time as an invisible framework that contains and constrains the Universe is not unlike the crystal spheres invented centuries ago to carry the planets. After the spheres had been shattered by Tycho Brahe's observations, Kepler said: "We must philosophise about these things differently." Much of modern physics stems from this insight. We need a new notion of time.

He's basically saying, "You might think I'm crazy but I'm really as insightful as Kepler! Save yourself the embarassment and support my ideas now!" Of course, Kepler actually came up with real equations, and Kepler's Laws provided meaningful insight into planetary motion. This article's author has not provided anything useful.

Here is the best support he can muster from other physicists:

Americans Bryce DeWitt and John Wheeler combined quantum mechanics and Einstein's theory of general relativity to produce an equation that describes the whole Universe. Put into the equation a configuration of the Universe, and out comes a probability for that configuration. There is no mention of time. Admittedly, the Wheeler-DeWitt equation is controversial and fraught with mathematical difficulties...

Wow, his best cite is contraversial and came up with a useless mathematical equation. He's really just using the idea that for any configuration of the universe, there is a probability that it exists. (But doesn't his article state that all configurations of the universe exist? We just experience them one at a time? Hmmm, sounds like a contradiction...)

The feeling I got from reading this article was that the author wasn't taken seriously by the academic community because his ideas are some subset of: {Trivial, Unprovable, Useless}. If this is an average article for Julian, then I agree with the academics.

-Ted