April 27, 2004

WHAT JOHN KNEW:

The Myth of the Beginning of Time (Gabriele Veneziano, 4/26/04, ScientificAmerican.com)

The unavoidable singularity poses serious problems for cosmologists. In particular, it sits uneasily with the high degree of homogeneity and isotropy that the universe exhibits on large scales. For the cosmos to look broadly the same everywhere, some kind of communication had to pass among distant regions of space, coordinating their properties. But the idea of such communication contradicts the old cosmological paradigm.

To be specific, consider what has happened over the 13.7 billion years since the release of the cosmic microwave background radiation. The distance between galaxies has grown by a factor of about 1,000 (because of the expansion), while the radius of the observable universe has grown by the much larger factor of about 100,000 (because light outpaces the expansion). We see parts of the universe today that we could not have seen 13.7 billion years ago. Indeed, this is the first time in cosmic history that light from the most distant galaxies has reached the Milky Way.

Nevertheless, the properties of the Milky Way are basically the same as those of distant galaxies. It is as though you showed up at a party only to find you were wearing exactly the same clothes as a dozen of your closest friends. If just two of you were dressed the same, it might be explained away as coincidence, but a dozen suggests that the partygoers had coordinated their attire in advance. In cosmology, the number is not a dozen but tens of thousands--the number of independent yet statistically identical patches of sky in the microwave background.


In the beginning was the word...

Posted by Orrin Judd at April 27, 2004 1:36 PM
Comments

It's not quite as bad as that, since the light we're seeing left 13 billion years ago as well, and we don't know what those regions look like today. Still, it's a nasty issue. The concept of cosmological inflation was invented specifically to address this issue.

Normally, then, inflation is viewed as a phenomenon of the very early Universe, which comes to an end and is followed by the conventional behaviour. Inflation does not replace the hot big bang theory; it is a bolt-on accessory attached at early times to improve the performance of the theory. [emphasis added]
Now, one can get this same result without recourse to inflation or other bolt-ons by assuming we got very, very lucky. An anthropic principle view might be that we wouldn't exist except for such luck (because Universes that don't start off that smooth either cool off too quickly or collapse too soon to form star systems). The Spinozan view is that God's intervention consisted of pre-selecting the initial state of the Universe to be in that infinitesmal area of phase space that leads to a smooth, populated Universe. Inflation, luck, remote Deity, unknown as yet mechanism - it's an open field.

Posted by: Annoying Old Guy at April 27, 2004 3:42 PM

Now this was synchronicity. I was just about to post something on the anthropic principle, and maybe even the related Doomsday Argument, because our discussions of Darwin are driving us that way.

Posted by: David Cohen at April 27, 2004 4:14 PM

I don't get the argument. Why wouldn't galaxies look the same across the universe? They are made of the same matter and follow the same laws. Why do they need to "communicate"? The analogy to party-goers is silly, galaxies are not conscious entities. Can't the ID advocates do better than this?

Posted by: Robert Duquette at April 27, 2004 4:51 PM

Robert:

The ID folks at Scientific American?

Posted by: oj at April 27, 2004 5:03 PM

Ugh. What an awful hash she's made of things in these paragraphs:

>To be specific, consider what has happened over the 13.7 billion years since the release of the cosmic microwave background radiation. The distance between galaxies has grown by a factor of about 1,000

There were no galaxies at the epoch of the CMB. That is basically the moment when the temperature of the universe cooled enough so that electrons and nuclei recombined. Before that time, the universe is opaque to radiation due to electron scattering opacity. After that time, radiation (light) can fly freely through the universe, and eventually reach us. Further back we can't see for this reason. Nothing like galaxies existed at that point.

>Indeed, this is the first time in cosmic history that light from the most distant galaxies has reached the Milky Way.

More nonsense. Galaxies form at something like a redshift of 7-10 or somewhat higher (we don't yet know), and the CMB is at a redshift of ~1000. Any astronomer with powerful enough telescopes could have seen both the most distant galaxies and the CMB ages ago.

>Nevertheless, the properties of the Milky Way are basically the same as those of distant galaxies...In cosmology, the number is not a dozen but tens of thousands--the number of independent yet statistically identical patches of sky in the microwave background.

Oh my. She's so confused. She is speaking of the fact that patches of the CMB in opposite regions of the sky all have the same temperature properties. In other words, they have been able to equalize their temperatures through heat flowing from hot to cold, even though they are far apart spatially that this should not have been possible. Again, nothing to do with galaxies. Even worse is her throwing the Milky Way into the mix. The Milky Way is a nice barred spiral sitting in a 15 billion year old universe. What connection does it have to observations of temperature from when the universe was only a tiny fraction of the current age (few hundreds of thousands of years)? Well, it grew out of fluctuations similar to what we see, but that's sort of like comparing you as an adult to your great-great-grandfather as a newborn.

Inflation was invented to address both this (the "horizon problem") and the "flatness problem" (which I've never found as compelling as the former). It's considered pretty indispensable to our modern picture of the universe. String theory, on the other hand, is still sniffed at by most mainstream astrophysicists.

Sorry for the length...

Posted by: brian at April 27, 2004 5:48 PM

Genesis 1:In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. . .

And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. . .


And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so. . .

-----------------


Although most commenters read the passage as describing creation ex nihilo. A number of medieval philosophers attempting to reconcile classical philosophy and biblical revelation read the passage to mean that God took eternal stuff that was chaotic (without form and void) and rearanged it into a working universe.

Scientists are going to have to stay up a lot later and work a lot harder if they are going to find an argument that theologians have not thought of during the last three thousand years.

Posted by: Robert Schwartz at April 27, 2004 6:15 PM

Robert:

That's true if you can twist the words to mean exactly whatever science has discovered.

AOG has it exactly right. In the beginning was the word.

Or not.

There's just no telling.

Posted by: Jeff Guinn at April 27, 2004 8:31 PM

There's only telling.

Posted by: oj at April 27, 2004 8:35 PM

I think it is the scientists who are doing the twisting. The text of Genesis is, at best, difficult, especially when read in the original. I do not adhere to the Johanine tradition and pass on its neo-platonism.

Posted by: Robert Schwartz at April 27, 2004 9:52 PM

Robert;

Check the link I put in my comment. There is some good introductory material that explains the smoothness problem. It's absolutely not an invention of the ID folk - it's a real problem for modern cosmology.

Posted by: Annoying Old Guy at April 27, 2004 11:47 PM

Sure they thought of everything, including the exact opposite of what's been quoted here. Notoriously, Genesis provides two, contradictory and irreconcilable accounts of Creation.

She sure is confused. According to us materialists, the Universe only exists where light (or similar particles) has reached. It cannot outspeed itself.

Posted by: Harry Eagar at April 28, 2004 12:10 AM

AOG: I was discussing Biblical interpretation not physics.

Harry: Creation Ex nihilo is an interpretation of ancient standing. But it is an interpretation. Classical philosophy held that matter and the cosmos were uncreated and eternal. Medevial philosophers seeking to reconcile the Bible and the Classics reinterpreted Genesis 1. I find their effort neither excesivley strained nor inhentely implausible.

When you say that: "Notoriously, Genesis provides two, contradictory and irreconcilable accounts of Creation." I assume you are reffering to the story of Adam and Eve in Gen 2. The stories are not contradictory but overlaping at days 5 and 6, and can be and have been reconciled (by minds far greater than mine) as far back as the composition of the Talmuds.

Posted by: Robert Schwartz at April 28, 2004 12:47 AM

Well, they can be reconciled, as every contradiction in the bible has been, by simply refusing to read the text.

But in one version, light was first and the other it wasn't.

Take your pick, but you get to pick only one.

Posted by: Harry Eagar at April 28, 2004 11:31 PM

the Word is Light

Posted by: oj at April 28, 2004 11:35 PM
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