Friday, October 17, 2008

More fine tuning stories here

New podcasts on fine tuning of the universe

Also: Gravity doesn't make sense? Hold on to that thought!

Multiverse: Getting comfortable with a zillion of everything that is unique?

Can the laws of physics evolve?

Like clouds in our coffee, all these other universes

Major media, imagining themselves sober, think there are many universes, not just double vision

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will the cosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?

More "who takes this multiverse stuff seriously?" stories here:

Cosmology: If you needn't worry about paying the rent Friday, you can worry aboutthis stuff

Cosmology: Science's leader in things that don't make sense

Cosmology: Crisis of the month: gravitation

Cosmology: Multiverse - getting comfortable with a zillion of everything that is unique.

Cosmology: I seem to have yanked particle physicist Lawrence Krauss's chain

Cosmology: Wow. It takes guts to wage warwith Stephen Hawking. He appeared in Star Trek

Cosmology: Arguments against flatness (plus exposing sloppy science writing)

Cosmology: If the universe has free will, where do I go to file a claim for damages?

Thursday, October 2, 2008

Dark energy, go gently into that good night ... and take the "Copernican Principle" with you ... ?

In "Scientists: Earth May Exist in Giant Cosmic Bubble" (October 01, 2008) Clara Moskowitz of Fox News reports,
Earth may be trapped in an abnormal bubble of space-time that is particularly devoid of matter.
Excuse me, I'm sure I've heard something like that before somewhere:
And the earth was without form, and void
It wasn't in a science class, but hey.

The concept of "dark energy" - a mysterious force no one understands - was developed to explain the universe today. But many scientists would like to get rid of dark energy as a concept because it is mysterious, which is not good for business.

And, as Moskowitz notes,
If we were in an unusually sparse area of the universe, then things could look farther away than they really are and there would be no need to rely on dark energy as an explanation for certain astronomical observations.
Ah, but, (diabolical music) - Cue The Devil:
One problem with the void idea is that it negates a principle that has reigned in astronomy for more than 450 years: namely, that our place in the universe isn't special.

When Nicholas Copernicus argued that it made much more sense for the Earth to be revolving around the sun than vice versa, it revolutionized science.

Since then, most theories have to pass the Copernican test. If they require our planet to be unique, or our position to be exalted, the ideas often seem unlikely.

"This idea that we live in a void would really be a statement that we live in a special place," Clifton told "The regular cosmological model is based on the idea that where we live is a typical place in the universe. This would be a contradiction to the Copernican principle."
Trouble is, the "Copernican Principle" was fashionable rot popularized by pop astronomer Carl Sagan, in part to promote theories about space aliens that supported science kitsch like the Drake Equation (= calculate your own likelihood of meeting a space alien).

It never had anything to do with Copernicus who would certainly have disowned it.

Earth could very well be in a giant bubble. We already know that it is in a very unusual position.

Anyway, the Joint Dark Energy Mission of NASA and the U.S. Department of Energy hopes to test the bubble thing in 2014 or 2015. They ask, Do we really observe galaxies rapidly accelerating away from us or do we observe objects being distorted in a void because, in yet another way, we are in an unusual position? It could look the same.

They hope to discover that the universe is really accelerating.

In Ars Technica, Matt Ford notes
This work represents a major departure from the currently accepted model of the universe, and it rejects a long-held tenet of astronomy and cosmology. Using the currently available data, the authors were unable to show that their model is closer to reality than the commonly accepted CDM description of the universe. Perhaps one of the biggest repercussions of this work, if correct, would be that we could no longer rely on our local measurements to describe the universe as a whole.
So the universe may not turn out to be what we expect? We shall see.

And see also:

"Privileged planet" astronomer Guillermo Gonzalez: Dissing St. Carl Sagan in his own church

Study: Sun not special, therefore alien life should be common?

Podcast: Cosmologist Paul Davies versus both the designed universe and the multiverse

Here's a podcast of Paul Davies, explaining his hypothesis of a non-ID non-multiverse hypothesis.

See also:

From the "missing the point" diaries: Anthropic topic? Or anthropic flopic?

Stuff I have already written on the bleeping multiverse, for which It, (Inc.) is suing me ... But the writ was sent to an infinite number of wrong universes, so ...

Space exploration: Stephen Hawking urges, Boldly go ... but why, exactly?

In "The final frontier," an online feature at Cosmos magazine (24 September 2008), Stephen Hawking, probably the world's best known living cosmologist, argues that we need to take space exploration seriously again:

In a way, the situation was like that in Europe before 1492. People might well have argued that it was a waste of money to send Columbus on a wild goose chase over an almost unimaginable distance. Yet, the discovery of the New World made a profound difference to the old one.
As it happens, a friend writes to say,

People did argue that, and they had good reasons, namely, that it was too far to sail to India. Columbus with some wishful thinking affecting his judgment gave a smaller circumference for the Earth. Lucky for him, North America turned out to exist. He wouldn't have been able to reach India. So Columbus's critics were right about India and the size of the Earth, but Columbus got lucky.
He advises us to read J. B. Russell's Inventing the Flat Earth: Columbus and Modern Historians, which points out that

Neither Christopher Columbus, nor his contemporaries, believed the earth was flat. Yet this curious illusion persists today, firmly established with the help of the media, textbooks, teachers--even noted historians. Inventing the Flat Earth is Jeffrey Burton Russell's attempt to set the record straight. He begins with a discussion of geographical knowledge in the Middle Ages, examining what Columbus and his contemporaries actually did believe, and then moves to a look at how the error was first propagated in the 1820s and 1830s--including how noted writers Washington Irving and Antoinne-Jean Letronne were among those responsible. He shows how later day historians followed these original mistakes, and how this "snowball effect" grew to outrageous proportions in the late nineteenth century, when Christians opposed to Darwinism were labelled as similar to Medieval Christians who (allegedly) thought the earth was flat. But perhaps the most intriguing focus of the book is the reason why we allow this error to persist. Do we prefer to languish in a comfortable and familiar error rather than exert the effort necessary to discover the truth? This uncomfortable question is engagingly answered, and includes a discussion about the implications of this for historical knowledge and scholarly honesty. (Product Description)

For the record, Columbus is one of those figures whose historical significance was accidental, which makes him ideal for myth-building. Many penniless adventurers like him washed up or drowned somewhere. He washed up in the Caribbean, and did not even know where he was - thus famously bequeathing the name "Indians" to the earliest known inhabitants of two great continents and all their surrounding islands.

The confusion Columbus accidentally created thereby lives on long after him. For example, today we have many Canadians of Aboriginal descent who resent being called "Indians" and many South Asian-born Canadians who really are from India. So Hawking's choice of Columbus to make his point was not altogether happy. Goodbye, Columbus.

Why go boldly into outer space? To explore inner space perhaps ...

Hawking's main point is to encourage more money for space exploration, specifically bases on the Moon and Mars:
Going into space won't be cheap, certainly, but it will take only a small proportion of world resources. NASA's budget has remained roughly constant in real terms since the time of the Apollo landings, but it has decreased from 0.3 per cent of U.S. GDP in 1970 to 0.12 per cent today.

Even if we were to increase the amount spent on space endeavours internationally by 20 times, to make a serious effort to send people into space, it would only be a small fraction of world GDP.

There will be those who argue that it would be better to spend our money solving the problems of this planet, like climate change and pollution, rather than wasting it on a possibly fruitless search for a new planet. I am not denying the importance of fighting climate change and global warming, but we can do that and still spare a quarter of a per cent of world GDP for space. Isn't our future worth a quarter of percent?
This argument sparked a lively discussion among friends. Is the analogy of space exploration with Europeans colonizing the Americas a fair one? Not really. The Europeans were looking for a quicker, cheaper, and safer route to India, a civilization with which they already had dealings. They already knew what luxury items they hoped to buy there. If space exploration were like that, we would now be trying to improve exchanges with an extraterrestrial civilization with which we already have fruitful contacts.

The fact that the Americas blocked the western route to India was a surprise discovery for the European explorers, but not a remarkable one. Other inhabited continents on a very life-friendly planet are nowhere near the odds of intelligent life elsewhere in the universe. For these reasons, the analogy to early modern European explorers does not really work.

However, a friend comments that the techniques developed for space exploration can be put to other uses:
It has been nearly 40 years from our original venture into space and moon landing and we are still reaping many benefits from the event. Most of the discoveries and applications were huge and largely unexpected. For example integrated circuit technology, biotelemetry monitoring, national defense and communication were forever changed as a result of our successfully putting a man on the moon. No doubt even larger technological breakthroughs will be made from learning how to accomplish deeper space travel and colonization of other worlds.
So instead of finding new continents, we will be founding new technology. In that case, the real purpose of the venture is to explore inner space (our own creativity) rather than outer space. On these lines, another friend, Edward Sisson, points to the spiritual value of such an exercise:

Colonizing other planets is basically the same as building a glorified space station. And what do we really do with that? All that effort so that two or three people at a time can spend a few months cramped in a can doing make-work.

The only real benefit of space travel is for mankind to exercise its collective mind accomplishing a worthy challenge. That is, in fact, a worthy reason to do it. But that is no justification for pretending that other benefits are likely.

We will now recite the Creed: "We believe that life arose spontaneously on the Earth."

In his article, Hawking also sums up current thinking about the origin of life, for which he hopes that space exploration will provide an explanation. In its own way, his comments are most illuminating. Not illuminating about the origin of life but about current thinking, for example:

We believe that life arose spontaneously on the Earth. So it must be possible for life to appear on other suitable planets, of which there seem to be a large number in the galaxy.

But we don't know how life first appeared. The probability of something as complicated as a DNA molecule being formed by random collisions of atoms in ocean seems incredibly small. However, there might have been some simpler macromolecule which was a building block for DNA or another molecule capable of reproducing itself.
Honestly, I've heard all this before, and I am not sure I would want to invest .25% of Earth's resources in it.

Panspermia, or an unidentified factor or force?

Hawking also gives a plug for panspermia, the theory that life originated elsewhere in the universe, and some other unexplained factor:

One piece of observational evidence on the probability of life appearing is that we have fossils from 3.5 billion years ago. The Earth was formed 4.6 billion years ago and was probably too hot for about the first half-billion years or so. So life appeared on Earth within half-a-billion years of it being possible, which is short compared to the 10-billion-year lifetime of an Earth-like planet.

This fact would suggest either panspermia or that the probability of life appearing independently is reasonably high. If it the probability very low, one would have expected it to take most of the 10 billion years available.
I am not sure what Hawking means by his suggested alternative to panspermia, that "the probability of life appearing independently is reasonably high." If so, something currently unknown must be driving it, because the probability is obviously not "reasonably high" if we assume random assembly, a fact that Hawking admits himself. Perhaps in his next essay, he will outline what he thinks that factor might be.

Were we meant to explore the universe?

Personally, I think that Guillermo Gonzalez's view that Earth's favourable position for astronomy suggests that we are somehow meant to explore the universe is far more inspirational for raising the required .25% of world GNP than anything Hawking cites in his article. After all, if we were meant to explore our universe, we can be sure that we will find something of consequence out there. Otherwise, maybe not. And the "otherwise" seems much closer to Hawking's position. And, after all, it is a lot of money.

Too bad Gonzalez's position proved so costly, and Hawking's position is so rewarding. Hawking worries in the article that young people are turned off science today. That, at least, should not be a mystery.

See also:

On Hawking

Stephen Hawking, miffed over science funding cuts, to move to Ontario, Canada?

Who reads popular books on cosmology? Well, almost everyone who actually reads, it seems

On Gonzalez

The truth hurts - and it can leave you seeing stars too

"Privileged planet" astronomer Guillermo Gonzalez: Dissing St. Carl Sagan in his own church

Study: Sun not special, therefore alien life should be common?