|
This page has the latest FQXi blog entries...the full text of the newest entries and
summaries of other recent entries. You may also view a list of all blog entries.
 RSS feed | RSS help
|
|
|
FQXi BLOGS
New Blog Entries
The Big Bang, and Before
By WILLIAM OREM • Jun. 18, 2008 @ 00:08 GMT
 | | image: andy emcee |
There’s good work coming out of Caltech this month supporting the idea – familiar to readers of FQXi Community – that the universe in which we live is the result of a spontaneous quantum fluctuation. This is the scenario often referred to in the press as “creation out of nothing,” a catchphrase that makes me cringe. Indulge me for a moment on this.
To put it flatly, “nothingness” doesn’t fluctuate. Nor does it do anything else -- including exist, if we follow the ontological implications of English and take “to be” as a verb. Here the language itself may be misleading us; I spoke with an Indian philosopher a few years ago who argued compellingly that we western thinkers are all hopelessly confused in our ontology by the simple fact that it is possible to employ “be verbs” in English without any object in the predicate. (Hang on – it’s painless.) We can say “the peach trees are,” for example, and stop there, without having to say *what* they are: green, fresh, tall, over here. Such a construction isn’t possible in all languages, and it may not be irrelevant. The tacit implication is that “the peach trees are” has meaning, which, when you think about it, cannot be demonstrated; and inasmuch as language is naturally assumed by speakers to reflect reality, the second implication is that “are” is therefore a quality among other qualities.
A lot of ink was spilled in the late 18th and early 19th century over this exact question, leading the German Idealists to demand such things as what the difference could possibly be between having five heavy, silver coins in my pocket and five heavy, silver, existing coins in my pocket. (Try it this way: if existence is a predicate, you should be able to make sense of the sentence, “I have five heavy, silver coins in my pocket, three of which exist.” If that sentence seems odd to you, re-consider “The peach trees are.” Now try “Three of the peach trees are.”)
It’s at least worth noting that the word “nothingness” itself contains a postulate that is by no means self-evident: namely, that “-ness” can meaningfully be attached to the term “no-thing” in the way it might be attached to “red” or “happy.” When we agree to the attachment we are ceding the strange point that there is a state or condition of being in no state or condition, something very much like “being not being.” Viewed this way, “nothingness” appears to be a round square.
In a similar vein I would submit that the phrase “emerged out of nothing” is grammatically sound but has no meaning, just as we can speak with perfect clarity but no content about a room full of married bachelors. The point is that the only quantum fluctuations with which we are familiar are embedded in spacetime, or are themselves expressions of spacetime, which we offhandedly refer to as “nothingness” or “emptiness” at our peril.
 | | image: edg1 |
I was talking with Andrei Linde recently, one of the fathers of the inflationary cosmology, and he shared my concern that caution is called for when discussing the idea of quantum fluctuations birthing universes. In his words, “It is okay to say [the universe emerged from a quantum fluctuation] in some allegorical sense which may help you to address this question. But you should just remember that your formulation is imprecise. When you are trying to make it precise, you must say, ‘What is this quantum fluctuation? Where did it live? If there was no space initially, then where was this fluctuation located?’”
One of the dangers – these are now my words -- is that the shorthand “emerged out of nothing” sounds too much like *creation ex nihilo,* triggering a host of religious associations that aren’t contained in the physical model. Quantum fluctuations are random events; they have no causal agent, no creator. It is remotely possible that measurement or consciousness ‘triggers’ some aspects of them, even if they exist in our relative past, but this still wouldn’t count as creation in the conventional sense.
More importantly, while not an object per se, a vacuum is still what some philosophers call “an existent” – that is to say, a given volume of spacetime is a *thing*. Vacua have complex properties, such as their expansion rates, their constant curvatures, and their energy densities. Dark energy or mere inertia? Superluminal inflation or standard metric expansion? Emptiness is these days regarded as a complicated physical phenomenon, a far cry from the existential nullity that so troubled King Lear.
So if our universe did not arise out of nothing, whence did it arise? Plausibly, out of somebody else’s universe.
Here's the BBC on the Caltech team:
"Although this microwave background is mostly smooth, the Cobe satellite in 1992 discovered small fluctuations that were believed to be the seeds from which the galaxy clusters we see in today's Universe grew.
Dr Adrienne Erickcek, from the California Institute of Technology (Caltech), and colleagues now believe these fluctuations contain hints that our Universe "bubbled off" from a previous one.
Their data comes from Nasa's Wilkinson Microwave Anisotropy Probe (WMAP), which has been studying the CMB since its launch in 2001."
 | | image: Atomicjeep |
The idea that certain regions, such as black holes, may bud off other universes within a larger hyperspace has already been floated by various cosmologists, notably the Perimeter Institute’s (and FQXi’s) Lee Smolin. Erickcek and her coworkers may have found supporting evidence for this rather wonderful claim. They also apparently link the model with another favorite topic among FQXi enthusiasts: the arrow of time. This they do by connecting the thermodynamic arrow and the strangely low-entropy past of our universe with its emergence from . . . well, from a previous existent.
BBC again:
"The second law [of thermodynamics] cannot be escaped, but Professor Carroll pointed out that it depends on a major assumption - that the Universe began its life in an ordered state.
This makes understanding the roots of this most fundamental of laws a job for cosmologists ( . . . )
In his presentation, the Caltech astronomer explained that by creating a Big Bang from the cold space of a previous universe, the new universe begins its life in just such an ordered state.
The apparent direction of time - and the fact that it's hard to put a broken egg back together - is the consequence.
( . . . )
If the Caltech team's work is correct, we may already have the first information about what came before our own Universe."
It is that final statement, both casual and startling, that turned my head. After all, it was only a few years ago that Pope John Paul II warned Stephen Hawking against studying the beginning of the universe, as this region was thought to be off-limits to mere mortals. Sinister consequences have often been dreamed to lurk behind the limits of the known, and surely the Big Bang is the ultimate limit. If not impious, asking what came before the Beginning must at least be hopeless, as nonsensical as hunting for those married bachelors.
But the history of the scientific enterprise has been one of relentless expansion – not just of knowledge, but of the horizons of knowledge. Thanks to people such as Erickcek, partly thanks to sites such as this one, the question of what that “nothingness” that came before everything actually was -- what nature looked like in the time before Time -- is becoming a little more commonplace. That doesn’t mean any particular pre-cosmos model is more or less likely to pan out, from Linde’s Eternal Chaotic Inflation to Hawking’s weird Instanton; but it does mean that scientific theories of what existed before our universe existed are becoming more *thinkable.*
And conceiving of something is, of course, the essential precondition of progress. First, we have to be able to imagine.
 | | image: Mshades |
Constructive Suggestions for Improving the FQXi Community Page
By KIRSTEN A. HUBBARD • May. 30, 2008 @ 14:25 GMT
FQXi welcomes your constructive suggestions for how we may improve our Community website. Thank you!
Gods and Astronomers
By WILLIAM OREM • May. 22, 2008 @ 17:52 GMT
It’s good news this month—of a sort—for Catholics who are also science-savvy. Jesuit astronomer Fr. Jose Funes has announced in the Vatican newspaper, L'Osservatore Romano, that it’s okay for followers of the Roman Catholic faith to believe in alien life. (That spinning sound you hear is Giordano Bruno.)
 | | image: markhillary |
From Catholic News.com:
"Father Funes said it was difficult to exclude the possibility that other intelligent life exists in the universe, and he noted that one field of astronomy is now actively seeking "biomarkers" in spectrum analysis of other stars and planets.
These potential forms of life could include those that have no need of oxygen or hydrogen, he said. Just as God created multiple forms of life on earth, he said, there may be diverse forms throughout the universe."
In other news, a good half of the famously missing mass of the universe has been spotted. And no, it isn’t dark: it’s baryonic. (I won’t say I told you so, but I told you so.)
 | | image: xamad |
From Discovery News:
"We think we are seeing the strands of a web-like structure that forms the backbone of the universe," said astronomer Mike Shull of the University of Colorado after an extensive search of the local universe.
"What we are confirming in detail is that intergalactic space, which intuitively might seem to be empty, is in fact the reservoir for most of the normal, baryonic matter in the universe."
Plus, an excellent article on “backward time” is now online from the relentlessly impressive people at Scientific American.com. It makes ideal late-Spring reading for anyone with a Foundational bent:
 | | image: John-Morgan |
"In other words, the real challenge is not to explain why the entropy of the universe will be higher tomorrow than it is today but to explain why the entropy was lower yesterday and even lower the day before that. We can trace this logic all the way back to the beginning of time in our observable universe. Ultimately, time asymmetry is a question for cosmology to answer."
Just don’t forget we told you so.
Finally, the “United Astrology Conference: Rockin’ the Universe” brought some 1,500 astrologers—I kid you not—from 45 different countries to Denver, where the mages of the heavens used their venerable skills to determine the winner of the next Presidential Election (hint: it doesn’t rhyme with “Don McLean” or “Pillory Tinton”). But beware: bad things happen, it turns out, when Saturn is opposite Uranus.
Best quotation from the various web accounts of this story:
"Sen. Barack Obama will win the presidency in the fall, according to seven top astrologers on a panel at the United Astrology Conference in Denver. One panelist, however, offered a caveat: 'We don't have a single solid birth chart,' Robert Hand said. 'If those dates are wrong, everything I say is garbage.'"
Good to know.
Does Time Actually Move?
By WILLIAM OREM • Apr. 24, 2008 @ 19:46 GMT
Perhaps the most lasting contribution to emerge from centuries of long-winded continental philosophy is the recognition that what nature does is distinct from what brains perceive. A perceiving consciousness is, of course, a perfectly natural phenomenon; brains have evolved to replicate external reality to a high degree of accuracy. I see no need in a modern, post-Darwinian age to resurrect Kantian armchair anxieties about the unknowability of the objective world. But it is still worth noting that every empiricist, physicist and loony with a theory about time has been nothing other than a human brain -- and has naturally based his or her proclamations on data as it is arranged inside brains.
Now brains are disentropic; they operate by accumulating organization. Consciousness itself may be dependent on, perhaps even in some sense equivalent to, steadily accumulating information. I can’t defend that claim, but I suspect it to be so; “static consciousness” seems a contradiction in terms, a fancy way of saying “brain death.” Trying to picture a consciousness that is not increasing its content is, in fact, a lot like asking whether a perfectly unchanging object would be getting any older. The question seems to lose its meaning.
This may be more than coincidence. I suspect what we essentially mean when we say “time is passing” is that at point Tuesday my brain has inside it organized information pertaining to State Monday but not State Wednesday. At point Wednesday my brain has organized information inside it regarding State Tuesday but not State Thursday. And so forth.
 | | image: gpwarlow |
The pedestrian way to interpret this is to say that my brain itself is moving through events, accumulating data as it goes, like snow blowing onto the windshield of a moving car. But suppose that car were “really” going backwards. That would mean that:
At point Wednesday my now backward-moving brain would have organized information in it regarding State Tuesday but no longer State Thursday. At point Tuesday my backward-moving brain would have organized information in it regarding State Monday but no longer State Wednesday. And so (anti)-forth.
These are identical situations. In one, my brain steadily accumulates data; in the other, it steadily loses data; yet all that really amounts to is the fact that at any given point I remember one direction and not the other. Entropy is in front, disentropy in back. However small a slice of time constitutes one “consciousness-instant” (presumably much, much larger than a natural chronon, if there is one), the backward-moving me will remain quite convinced that he is moving forward. And indeed, he will have every grounds for believing this, since his perception will be exactly the same in either direction.
This is the peril any science fiction narrative involving time-machines runs into: the brains and bodies of the time-travelers must not *themselves* move backward in time when they hit the Way-Back button, or their situation would be indistinguishable from normal forward motion. Setting the Way-Back Button to ten minutes would not only trap our travelers in an endless twenty-minute loop but prevent them from ever discovering that this had happened.
 | | image: fdecomite |
The point? Just that if moving forward is phenomenologically equivalent to moving backward, it’s clear that remaining static must be equivalent to *both*. A “block time” universe in which brains not move at all, but simultaneously occupy states Monday, Tuesday, Wednesday, would still contain, at every “consciousness-instant,” a consciousness that absolutely experiences itself as moving forward. How could it not? If consciousness is a function of increasing organization, then as long as the circuits are running, it will necessarily perceive itself to be evolving in the direction of increased content.
To be aware at all, in this way of thinking, is to experience unidirectional time—regardless of whether this corresponds to anything “out there.”
If the world ended tomorrow, would we notice?
By ANTHONY AGUIRRE • Mar. 31, 2008 @ 16:17 GMT
In recognition of FQXi of Doomsday week, suppose the world ended tomorrow. In particular, suppose that, as discussed in Kate Becker's fun article, we live in a 'false vacuum', that can decay to a lower energy state. The decay would take the form of a bubble of 'true' vacuum that grows at the speed of light, smashing into us with enormous energy without warning, annihilating everything we hold dear (even, perhaps, our beloved local laws of physics). Seems pretty noticeable.
But bubble formation is a quantum process, and we should think about what this means. Suppose we take a big region including both us and the bubble's formation location, and describe it as a quantum system with some set of states, interacting with its environment. When 'the bubble nucleates', it is something like a quantum measurement, and we can say that our quantum system is in a state containing something like a decohered superposition of our region with the bubble, and our region without the bubble. What we would mean by 'the bubble hits us' is that we find that we are in the branch of the wavefunction in which the bubble has, indeed, formed. But (unless we adhere to an interpretation in quantum mechanics in which the usual Schrodinger equation is actually violated), the other branch is still there too, at least mathematically.
Now suppose we adhere to the 'Many Worlds' interpretation, in which there is some sense in which both branches are supposed to be 'equally real'. I then must think of something like an ensemble of equally-real Anthonys, some of which get smashed by bubbles and some of which do not. And with each of these is a corresponding reader (you) that either gets smashed or not, perhaps a fraction of a second earlier or later. Now again I ask the question: if the world ends tomorrow, would you notice? Unless there is some aspect of awareness completely independent of your instantly-incinerated physical body, I can see no sensible meaning to 'you notice the bubble destroying you.' On the other hand, there are plenty of copies of you in the ensemble -- those with no bubble -- that go merrily along with their lives. Presumably the day after tomorrow 'you' are simply one of those, and 'I' am one of the corresponding surviving Anthonys. In short, how could we say with any confidence that we do *not* live in an unstable false vacuum? (An attempt to answer this using statistical arguments concerning what the 'survivors' would see was given by Max and Nick Bostrom in this paper, check it out.)
This "quantum immortality" line of thought (which I first realized some time ago after reading Mad Max's quantum suicide paper, though I'm sure I was not the first to realize) is disturbing enough that it is natural to wonder which one of its assumptions we can most easily discard. You might choose to believe that you have a non-corporeal -- and hence bubble-proof -- immortal soul that can nonetheless meaningfully notice that you have died. This might be fun to believe but I have not had much luck doing so myself. More obviously, you might choose to throw out the Many Worlds interpretation (which you my have already thought was nuts, and this just confirms it). But consider this: suppose the Universe is infinite, which is all the rage in inflationary cosmology and in any case seems a plausible cosmological possibility. Then it seems that we can define an (infinite) ensemble of regions that are identical except for the nucleation or non-nucleation of a bubble. In fact, I'm pretty sure -- as Max & I recently convinced ourselves -- that an ensemble can be defined that is *exactly* equivalent to the quantum mechanical one describing an individual system in the Many World interpretation. Thus even if you think a single measurement in some particular place has just one outcome, the net effect (in an infinite universe) precisely echoes what happen in Many Worlds: "cosmological immortality".
And you didn't notice that the world ended as you read that last sentence.
Recent Blog Entries
. . . and a Side of Obliteration
By WILLIAM OREM
Next April 1st-themed Item: In the mood for total planetary annihilation?
Strange to say, there is a veritable genre these days of websites, discussion boards and other resources dedicated to the burning question of how to destro...
Dark Matter: the Lighter Side
By WILLIAM OREM
I’m not a nut, but I entertain at least one nutty idea. I can’t imagine any way for my nutty idea to be tested (that hasn’t stopped string theory), and I don’t see why anyone would want to test my idea—it’s nutty. But since it’s April 1st,...
Do You See Dark Matter?
By WILLIAM OREM
The good news is, it's foundational either way.
In one version, a whopping 4% of the energy density of the universe is baryonic. Another way to say this, of course, is almost everything that exists is completely unknown to us—and si...
Unidentified Foundational Objects
By WILLIAM OREM
The thing I respond to most strongly in these posts is the passion with which the issue is regarded on all sides. Whether we come down for or against counting UFO stories as credible evidence (of something), whether we hear about aberrant ...
Are UFOs Foundational?
By WILLIAM OREM
Readers of this blog have been pressing me (offline) this month with a sensible question: why am I not discussing the Stephenville UFO? After all, what could be more paradigm-shifting than solid evidence of sentient, technologica...
Hunting LGM
By WILLIAM OREM
Time to upgrade that so-last-season flip phone you are still carrying around in favor of a flashing lightweight earpiece? Tech moves so fast these days, in part thanks to the Law of Accelerating Returns, we've hardly time to show off the l...
Bang / Crunch / Bang
By WILLIAM OREM
I was contacted recently by Peter Lynds, the young physics iconoclast who turned some heads back in 2003 with a paper purporting correctly to resolve Zeno's paradox by defining time as having no quantized base unit, even in principle. (Ful...
An Exceptionally Simple Personal FAQ
By A. GARRETT LISI
Over the past month I have been asked many questions about my personal history and opinions on life, the universe, and everything. I have also received many emails of encouragement from the general public, which have been wonderful and completely ...
The Big-Bang versus the Big-Bang
By ANTHONY AGUIRRE
"Big-bang" versus "Big bang"
I spend a good bit of time thinking about what happened in the period of time between the Big-Bang and the Big-Bang. No, I'm not crazy (or at least not with respect to this issue). Rather, the problem is that ...
A Hole in Messier
By WILLIAM OREM
The sci-fi loving public and foundationally minded cosmologists alike are enamored of black holes. Black holes, as everyone knows, form from the crushed remains of certain burned-out stars -- those of a particular size whose gravitational...
|
|
|
