Category Archives: Philosophy

A Guide to Reality, Part 7

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In the final pages of chapter 2 of The Atheist’s Guide to Reality: Enjoying Life Without Illusions, Alex Rosenberg turns to some big, persistent questions he believes are now answered by physics.

– Where did the universe come from, how long ago, and where is it going?

Rosenberg accepts the standard view that the universe began with a “big bang” about 13.75 billion years ago (13.80 according to the latest Wikipedia update). The universe started out extremely hot and extremely dense and has been expanding ever since, creating spacetime, subatomic particles, the elements, stars and galaxies along the way. The expansion seems to be speeding up, but it’s not clear why.

Rosenberg gives the impression that the universe began as a tiny sphere, reaching the size of an orange in much less than a second. The physicist who answers questions at the “Ask a Physicist” website, however, says that the universe didn’t really explode from a tiny point, despite what every documentary and planetarium show implies. He says we should think of the early universe as being like an infinite, very hot, very dense rubber sheet that suddenly began to stretch (although he admits that it’s hard to picture something infinite becoming larger without doing the math). 

One aspect of the big bang that’s always bothered me is its location. Physicists often imply that it didn’t have a location, since spacetime didn’t exist before the big bang occurred. Rosenberg, however, says there is a small region of space where the cosmic background radiation is more intense than anywhere else. He refers to this as “the source of the big bang”. The “Ask a Physicist” physicist says that the oldest light we can detect came from somewhere 46 billion light-years away, much further away than the 14 light-years we would expect from the age of the universe (the difference is the effect of cosmic expansion). So if there is a region of space some 46 billion light-years away that appears to have been the location of the big bang, I have dibs on running the first snack bar and gift shop.

– Where did the big bang come from?

Rosenberg favors one of the leading theories:

The best current theory suggests that our universe is just one universe in a “multiverse” – a vast number of universes, each bubbling up randomly out of the foam on the surface of the multiverse, like so many bubbles in the bathwater, each one the result of some totally random event.

Of course, I have no idea whether the multiverse theory is correct, but it doesn’t seem right to assume that whatever happens in the multiverse is totally random. Most physicists believe that events at the quantum level in our universe are random, but others think that there might be non-random causes underlying the quantum level. Even if quantum events in our universe are random, why assume randomness to be the rule in other universes or in the larger multiverse? Maybe randomness or apparent randomness is simply a feature of the universe we live in.

Rosenberg is certain that everything that happens at the quantum level in our universe, everything that happened in the pre-big bang universe, everything that happened before that in the multiverse, and even everything that is happening in the multiverse right now is fundamentally random. But this seems like conjecture on his part, especially since nobody knows what physical laws were in effect before the big bang or are in effect in the multiverse (if such a thing even exists). 

– Why is there something rather than nothing?

Some philosophers, scientists and theologians consider this to be the deepest question of all. According to Rosenberg, the answer is:

No reason at all. It’s just another quantum event. What science and scientism tell those who hanker for more is “Get over it!”

If Rosenberg is simply telling us what today’s best science has to say about the origin of all existence, he’s probably right. Either there has always been something (there never was a first cause or a prime mover) or one day something simply happened to pop into existence. Rosenberg’s project, however, is both to explain what science tells us and to convince us that scientism provides the answers we need to live without illusions (“the methods of science are the only reliable ways to secure knowledge of anything” and “science provides all the significant truths about reality”). I think it would be more rational to confess that we don’t know and may never know why there is something rather than nothing. Science might be the most reliable way to secure knowledge, but it hasn’t given us knowledge of everything.

– What is the purpose of the universe?

As should be expected by now, Rosenberg’s answer is short and to the point. There isn’t any purpose to the universe at all. He points out that physicists have been tremendously successful at explaining natural phenomena without resorting to purposes (what philosophers call “teleological” explanations). Smoke doesn’t rise because its purpose is to get higher. Rosenberg is sure that the universe wasn’t created as someone’s science experiment and we aren’t all living in some kind of enormous virtual reality contraption. He’s probably right, but it seems to me that he’s going beyond science here. The best that can be said in support of his position is that, according to the best science we have, the universe functions without purpose. Contemporary physicists don’t need to invoke purpose or purposes to explain what happens in the universe. Furthermore, there is no reason to suppose that future physicists will need to invoke purpose to explain why there is a universe, assuming that they are ever able to come up with an explanation at all.

– Why does the universe have the laws of nature and the physical parameters that make intelligent life possible?

It’s often pointed out that if the laws of nature or the basic physical parameters (like the charge on an electron) were slightly different, the stuff we’re made of couldn’t exist, so neither would we. Physicists have come up with different explanations for this fact of life (the theoretical physicist Lee Smolin offered a theory called “cosmological natural selection” in his book The Life of the Cosmos). Of course, some thinkers have concluded that God must have designed things this way to make a nice home for people like you and me. Having accepted the multiverse theory as the best theory we have, however, Rosenberg concludes that we’re just lucky. Given that a multitude of universes have arisen from the multiverse, it stands to reason that some of them are like ours. We won the cosmic lottery. 

Maybe he’s right (although some days I don’t feel like a winner). Personally, I’m reserving judgment.

Coming up in part 8: “How Physics Fakes Design”.

A Brief History of the Philosophy of Time by Adrian Bardon

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Someone thought it would be a good idea to call this book A Brief History of the Philosophy of Time, no doubt as an allusion to Stephen Hawking’s A Brief History of Time. The book’s focus isn’t historical, however. It’s a brief introduction to the philosophy of time, with chapters devoted to the nature of time, its direction, its passage, and a few other standard topics. Professor Bardon’s explanations of the issues are almost always clear and the book is relatively easy to read.

The most interesting aspect of the book is Bardon’s strong preference for the “static theory of time”. That’s the counter-intuitive view that the apparent passage of time is an illusion, or, more precisely, that it’s merely the result of our human perspective. The static theory isn’t new. The Greek philosopher Parmenides argued for it 2,500 years ago. J. M. E. McTaggart unhelpfully gave the name “B-series” to this conception of time, distinguishing it from the more familiar “A-series” or “dynamic theory of time” that most people accept, according to which time passes as events move from the future to the past:

The static theorist believes in change, but only understood in a way that doesn’t commit one to the passage of time: Change, on the static theory, is to be understood as merely referring to the world being timelessly one way and timelessly another way at a subsequent moment.  

The B-series places every event in the history of the universe on an unchanging timeline. On this view, it‘s appropriate to describe every event as either earlier than, later than or simultaneous with every other event. But there is no special significance to the present moment (the “now”). It’s no more descriptive to say that an event is happening “now” than to say that a location is “here” or a direction is “up”. The idea that some events are in the past or future compared to the present moment is an illusion. So far as our “block universe” is concerned, all moments in time are equally real, not just the present one.

The static view of time isn’t universally accepted, but it’s popular among physicists and philosophers. One reason Bardon accepts it is that he thinks McTaggart’s arguments for the static theory and against the passage of time are “devastating”.

I think they’re confused. For example, McTaggart and Bardon hold that it’s self-contradictory to say that an event like the 1960 World Series used to be in the future and is now in the past, since by doing so we are attributing contradictory properties (being past and being future) to the same thing (a particular event). But being past or future are relational properties that vary with time. Saying an event was future and is now past is akin to saying a person was married and is now divorced, hardly a contradiction.

Bardon also presents Einstein’s theory of special relativity as a reason for doubting that time passes. Physicists have confirmed that two observers moving at great speed relative to each other will perceive time differently. For this reason, there is no place in physics for saying that two events are truly simultaneous, or which of two events happened first, except from a particular point of view: 

If there is no privileged vantage point from which to determine the “truth” of the matter – and the whole point of relativity is that there is not – then temporal properties like past, present and future cannot possibly be aspects of reality as it is in itself. They must be subjective and perspectival in nature.

Yet the theory of relativity pertains to how events can be observed or measured, given the constant speed of light. It doesn’t tell us how reality is “in itself”; it tells us how reality is perceived. Just because we can’t always know when two events occurred doesn’t mean there is no truth to the matter. A truth can be unknowable.

Furthermore, if relativity implies that there is no objective A-series past or future, it also implies that there is no objective B-series “earlier” or “later”. Bardon tries to draw a distinction between relativity’s implications for the dynamic and static theories of time, but it isn’t convincing. Perhaps the book would have been better if Bardon hadn’t so clearly taken sides.

A Guide to Reality, Part 6

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In the rest of chapter 2 of The Atheist’s Guide to Reality, Alex Rosenberg explains the second law of thermodynamics and briefly addresses some of humanity’s “persistent questions” (such as “does the universe have a purpose?”). His account of the second law is much less controversial than his answers to those big, long-standing questions.

The second law of thermodynamics is usually summed up, somewhat inaccurately, as “entropy or disorder always increases”. Rosenberg, however, begins with this description:

The second law tells us that in any region of space left to itself, differences in the amount of energy will very, very, very probably even out until the whole region is uniform in energy, in temperature, in disorder…. In our universe, the arrangement of everything goes from more improbable distributions (with more useful energy) to less improbable ones (with less useful energy). And the same goes for any self-contained part of the universe (28-31).

In other words, everything that somehow became organized will eventually fall apart (which is one reason why long-abandoned houses invariably look worse than occupied ones). An organized system is unlikely. Energy must be applied to create it and, without further energy being added to the system, it will sooner or later revert to the much more likely state of being disorganized.

Consider, for example, the atoms and molecules that make up the Eiffel Tower. It’s much less likely that they ended up being arranged in that shape than if they were randomly spread around here and there:

The most probable distribution of energy and disorder in the universe is the completely even distribution of everything….[That] is the state toward which, according to the second law, everything is moving, some places slower, some places faster, but almost inexorably. This evening-out of things – from molecules to galaxies – from less probable to more probable distributions is the rule of the universe (31).

Increasing disorder isn’t completely guaranteed, however, which is why Rosenberg says “almost inexorably”. As he explains, the second law merely means that the tendency toward disorder is extremely, extremely probable. For example, when you pour cream in your coffee, the two liquids quickly mix together. But there is nothing in the laws of physics that prohibits the cream from spelling “Good Morning” when you drop it in.

So why are there so many unlikely, highly-organized clumps of matter around (like us)? Despite what some evolution-deniers think, these clumps aren’t counterexamples to the second law. Nor are they bizarre but permissible, random bits of organization:

These are regions of the universe in which the maintenance of order is being paid for by using much more energy to produce [and maintain] the orderly things than the amount of order they produce or store. Each region of local order is part of a bigger region in which there is almost always a net increase in entropy…. Most biological order is preserved for long periods, but at the cost of vast increases in disorder elsewhere (32).

Physicists believe that the universe began in a state of incredibly extreme heat and density. Rosenberg says that this primordial state was both highly unlikely and highly organized, although “organized” might not be the best word.

If everything in the pre-Big Bang universe was evenly distributed (unlike all the molecules in the neighborhood of, for example, the Eiffel Tower), it seems odd to say that it was organized at all. It’s not as if there was some cold, thinly-populated, disorganized space different from the hot, dense stuff, waiting to be filled up. The dense stuff that existed at that point was All There Was. Unless it had some internal structure, we might as well say it wasn’t organized at all. At any rate, the universe as a whole has been falling apart (moving toward perfect equilibrium) ever since the Big Bang, despite the fact that here and there stars and galaxies eventually came to be.

Somewhat controversially, Rosenberg suggests that the second law also explains why time appears to have a “direction”:

Hard to believe, but the second law is where the direction of time, its asymmetry, comes from. It cannot come from anywhere else in physics. By process of elimination, the time order of events from earlier to later is a consequence of the second law…. None of the basic laws of physics [allow us to tell which way is past and which way is future] except for one: the second law of thermodynamics. It makes a difference between earlier times and later times: the later it gets, the more disorder, or entropy, there is (33-35).

On the other hand, another philosopher, Adrian Bardon, argues in A Brief History of the Philosophy of Time that the second law can’t explain the apparent direction of time. The second law is merely probabilistic, as Rosenberg admits. Increasing entropy is extremely, extremely likely, but not absolutely guaranteed, even for the universe as a whole. But the direction of time, if it’s real, is supposed to be unchanging, not probabilistic. Bardon concludes that the direction of time can’t be the same as the one-way, thermodynamic “direction” suggested by the second law. He thinks the fact that these two “directions” appear to go the same way is just a striking coincidence.

This brings us to Rosenberg’s brief answers to a few of those big, persistent questions. This post being so long already, however, I’ll end for now with a brief summary of his conclusions:

Where did the Big Bang come from? We don’t know, but the best current theory is that it randomly emerged from the “multiverse”. Our universe is just one of many.

Well, why is there a “multiverse” then? There’s no reason for it to exist. It just does. Get over it already!

But isn’t there some purpose to the universe? No, there isn’t any purpose to it at all.

But why then does the universe have the physical laws and parameters that allow intelligent life to exist? Given the vast number of universes popping into existence, it shouldn’t be a surprise that some of them end up being like this one. Somebody had to get a winning ticket in the cosmic lottery. It happened to be us.

In our next installment: Oh, really?

Bet on Achilles to Beat the Tortoise

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Many are the times I’ve thought about Achilles and the tortoise:

Zeno concluded from this and other paradoxes that motion is an illusion, so it’s important to show why Achilles will beat the tortoise. Otherwise, we’ll all have to sit very still.

Zeno’s argument goes something like this:

1) When Achilles starts running at point A, the tortoise is already at B.
2) By the time Achilles reaches point B, the tortoise is at point C.
3) By the time Achilles reaches point C, the tortoise is at point D.
4) This series can be extended forever.
5) In order to catch up, Achilles will have to perform an infinite series of tasks in a finite amount of time.
6) It’s impossible to perform an infinite series of tasks in a finite amount of time.
7) Therefore, Achilles can never catch up to the tortoise.

But we know that mighty Achilles is going to catch up to the tortoise and win the race. Fast runners beat slow walkers. Hence, the paradox.

In his book A Brief History of the Philosophy of Time, Adrian Bardon suggests that Aristotle had a good response to Zeno. Aristotle apparently argued that Zeno’s paradox rests on confusing “an abstract value (i.e. time), which is mathematically divisible into instants, with actual change, which is not literally composed of infinitesimal units of change”. In other words, Aristotle distinguished between “the rules for time (as a mere abstraction) and those for change (as a real phenomenon)”. Maybe Aristotle was right, but I’m not sure Zeno would have been convinced.

Bardon also discusses the mathematical concept of a “limit”, which “allows for an infinite number of finite quantities to add up to a finite sum”. That’s the idea mentioned at the end of the video. Many have concluded that Zeno can be answered using this concept, although Bardon asks: “Can a limit be a real endpoint to a real process, or is it just a new mathematical convention that disregards the metaphysical question about time and change with which Aristotle and Zeno are struggling? Does it really help matters to say that [motion or change] represents convergence on a limit? That wouldn’t have sounded like real motion to either Zeno or Aristotle”.

Maybe Zeno’s argument does require a subtle and sophisticated response. But what struck me as weak about his argument was one of the premises listed above:

6) It’s impossible to perform an infinite series of tasks in a finite amount of time.

Really? Who says? Isn’t that what we do every time we move from point A to point B? Having arrived at point B, haven’t we also traveled 1/2 of the distance, 1/3 of the distance, 1/4 of the distance, 1/5 of the distance and so on? Isn’t this a clear example of performing an infinite series of tasks in a finite amount of time? Granted that the tasks overlap, but it seems fair (albeit boring) to describe what we’ve done this way, without having to explain what the mathematical concept of a “limit” is or draw a distinction between the rules for speaking about time and the rules for speaking about change.

Perhaps this is mere sophistry and Zeno would have considered it such, since he and the Sophists were contemporaries. I think it’s a simple truth that moving around involves doing many little things by doing one big thing. Take that, Zeno!

On a similar note, the English philosopher G. E. Moore wrote a famous article called “Proof of an External World”. In that article, he said he could prove the existence of the world outside our minds by drawing our attention to his two hands: “by doing this, ipso facto, I have proved the existence of external things”. Whether that’s a great argument or not is an open question. Moore defended his argument, however, by pointing out that skeptical philosophical arguments (such as proving motion to be an illusion) often rely on philosophical intuitions or generalities (such as premise 6 above) that we have much less reason to accept than the common sense beliefs they supposedly refute.

All right, it’s safe to start moving again.

A Guide to Reality, Part 5

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Alex Rosenberg, the author of The Atheist’s Guide to Reality, argues that “we should embrace physics as the whole truth about reality”. On the face of it, that’s a remarkable statement open to obvious challenges. 

Rosenberg, however, acknowledges that parts of physics are relatively speculative, unsettled or even inconsistent. It’s the solidly-confirmed part of physics that he’s talking about, the part of physics that is “finished” and “explains almost everything in the universe – including us”. What he’s really claiming, therefore, is that settled physics is the whole truth about reality. 

But is settled physics actually true? Philosophers disagree about what science is, what truth is and, not surprisingly, how close science gets to the truth, but I agree with Rosenberg that settled physics seems to be true. The predictions of special relativity, for example, appear to be 100% correct. (This isn’t to deny that some settled physics might become unsettled one day.) As evidence of the reliability of physics, Rosenberg points out how precise some predictions are: “quantum electrodynamics predicts the mass and charge of subatomic particles to 12 decimal places”. Those predictions are “true” in any reasonable sense of the word, even if physicists eventually refine their predictions to even more decimal places.

Some philosophers and scientists don’t accept Rosenberg’s “scientific realist” view, however. They think science is merely a tool that allows us to get things done. Questions like whether electrons or other theoretical entities really exist as physics describes them are put aside, since they’re viewed as unanswerable and irrelevant. Personally, I think physics allows us to get things done because it’s true, and furthermore it’s true in the sense that the objects and events physics describes are real, whether they’re observable or not. I believe that’s Rosenberg’s opinion too.

The second, more interesting challenge to Rosenberg’s view of physics concerns his claim that settled physics is the “whole” truth about reality. Clearly, there are mathematical and logical truths, which aren’t part of physics, but I take Rosenberg to be referring to truths about the universe and its contents, i.e. “real” stuff.

Nevertheless, if physics isn’t finished, it can’t be the “whole” truth. There must be some physical truths yet to be discovered (for example, what’s the story on dark matter and dark energy, two big things we know little about?). So Rosenberg’s claim that we should embrace settled physics as the whole truth about reality should really be understood as “settled physics is the only truth about reality we currently have”.  

Two obvious questions remain, however. Do we discover the truth from sciences other than physics? And do we learn anything true about the world even when we aren’t doing science?

Well, most people would agree that chemistry, for example, is a science that gets at the truth if any science does. Rosenberg clearly knows about chemistry, so why would he deny that chemistry is as valid as physics? The answer is that he thinks physics has shown there is nothing in the universe except fermions (e.g. quarks) and bosons (e.g. photons). From the idea that fermions and bosons are the only things that really exist, he concludes that all of reality can be explained in terms of those sub-atomic particles. After all, everything in the universe involves elementary particles being somewhere or doing something. Since physics is the science that tells us all about elementary particles and what they do, it’s the fundamental science. Using physics, therefore, we can explain chemistry, which we can then use to explain biology. Another way of saying this is that biology is reducible to chemistry and chemistry is reducible to physics. Knowledge of physics is the only knowledge that counts, because “the physical facts fix all the facts”, including chemical and biological facts.

The big problem with this point of view, aside from the difficulty in actually carrying out such reductions (replacing chemistry with physics, for example) is that fermions and bosons do such interesting things when they interact or are arranged in certain ways. Put some together and you have atoms; put some atoms together and you have molecules; put some of them together and you have cells. Once low-level particles are arranged as, for example, clouds or baseballs or trees, patterns or regularities in the behavior of these higher-level entities emerge. There are new facts to be learned.

If the universe were merely a collection of sub-atomic particles randomly scattered about, there wouldn’t be any chemical or biological facts for chemists and biologists to discover. But the particles in our universe aren’t randomly scattered. They’ve clumped together in various ways. Acquiring knowledge about these clumps (of which you and I are examples) is what chemists, biologists and other scientists (geologists, astronomers, psychologists, etc.) do. Rosenberg knows this, of course, but for some reason downplays it, choosing to focus on physics as the sine qua non of science. In virtue of its power and generality, physics should be embraced as the most fundamental science, but it clearly isn’t the only science worth embracing. 

The other question raised by Rosenberg’s scientism (or physics-ism) is whether we can add to our knowledge when we aren’t doing science at all. Rosenberg doesn’t seem to think so. Although science is built on observation, he is extremely skeptical about what can be learned by simply looking and listening. He also seriously mistrusts introspection. More on this later. 

Next: The 2nd Law of Thermodynamics and us.