Category: cosmology

Steven Weinberg discusses the mysteries of physics

October 20, 2013 • 6:45 am

A common misconception is that the major problems of physics have mostly been solved, and all that’s left is some minor sweeping-up.  I doubt that the readers here would agree, for huge surprises and mysteries continue to surface in physics. In a new piece in the New York Review of Books, “Physics: What we do and don’t know” (free download), Nobel Laureate Steve Weinberg discusses these puzzles, which occur on scales both large and small.

I found a bit of the piece tough going, as if Weinberg were writing for professionals instead of science-friendly and educated people. I had trouble with this, for example:

Speculations of this sort ran into an obvious difficulty: photons have no mass, while any new particles such as W+, W-, and Z0 would have to be very heavy, or they would have been discovered decades earlier—the heavier the particle, the higher the energy needed to create it in a particle accelerator, and the more expensive the accelerator. There was also the stubborn problem of infinities. The solution lay in an idea known as broken symmetry, which had been developed and successfully applied in other areas of particle physics since 1960. The equations of a theory may possess certain simplicities, such as relations among the photon, W+, W-, and Z0, which are not present in the solutions of the equations that describe what we actually observe. In the electroweak theory there is an exact symmetry between weak and electromagnetic forces, which would make the W+, W-, and Z0 massless, if it were not that the symmetry is broken by four proposed “scalar” fields that permeate the universe, from which the W+, W-, and Z0as well as the electron get masses. A new particle discovered last year appears to be the predicted quantum of one of these scalar fields.

But the bulk of the piece is a very nice summary of what we do and don’t know, and I recommend it warmly.  Here are some of the mysteries, with Weinberg’s take indented:

1. What is dark matter?

It turns out that particles already known to us are not enough to account for the mass of the hot matter in which the sound waves must have propagated. Fully five sixths of the matter of the universe would have to be some kind of “dark matter,” which does not emit or absorb light. The existence of this much dark matter in the present universe had already been inferred from the fact that clusters of galaxies hold together gravitationally, despite the high random speeds of the galaxies in the clusters. So this is a great puzzle: What is the dark matter? Theories abound, and attempts are underway to catch ambient dark matter particles or remnants of their annihilation in detectors on Earth or to create dark matter in accelerators. But so far dark matter has not been found, and no one knows what it is.

2. What is dark energy?

In 1998, using the apparent brightness of exploding stars to measure the distance of far galaxies, two groups of astronomers found that the expansion of the universe is not slowing down at all, but rather speeding up. Within the rules of the general theory of relativity, this could only be explained by an energy that is not contained in the masses of any sort of particles, dark or otherwise, but in a “dark energy” inherent in space itself, which produces a sort of antigravity pushing the galaxies apart.

From these measurements, and also from studies of the effect of the expansion of the universe on the cosmic radiation background, it has been found that the dark energy now makes up about three quarters of the total energy of the universe.

3. How does gravity fit into the “theory of everything”? Weinberg got his Nobel (along with Abdus Salam and Sheldon Glashow) for unifying the electromagnetic and weak forces. But one “force” has so far defied unification.

Even so, the standard model is clearly not the final theory. Its equations involve a score of numbers, like the masses of quarks, that have to be taken from experiment without our understanding why they are what they are. If the standard model were the whole story, it would require neutrinos to have zero mass, while in fact their masses are merely very small, less than a millionth the mass of an electron. Further, the standard model does not include the longest-known and most familiar force, the force of gravitation. We commonly describe gravitation using a field theory, the general theory of relativity, but this is not a quantum field theory in which infinities cancel as they do in the standard model.

4. Is string theory right?

Since the 1980s a tremendous amount of mathematically sophisticated work has been devoted to the development of a quantum theory whose fundamental ingredients are not particles or fields but tiny strings, whose various modes of vibration we observe as the various kinds of elementary particle. One of these modes corresponds to the graviton, the quantum of the gravitational field. String theory if true would not invalidate field theories like the standard model or general relativity; they would just be demoted to “effective field theories,” approximations valid at the scales of distance and energy that we have been able to explore.

String theory is attractive because it incorporates gravitation, it contains no infinities, and its structure is tightly constrained by conditions of mathematical consistency, so apparently there is just one string theory. Unfortunately, although we do not yet know the exact underlying equations of string theory, there are reasons to believe that whatever these equations are, they have a vast number of solutions. I have been a fan of string theory, but it is disappointing that no one so far has succeeded in finding a solution that corresponds to the world we observe.

String theory, combined with the idea of cosmic inflation, leads naturally to the concept of multiverses, “pocket universes” in which the laws of physics would differ from those of our own universe. This possibility, if confirmed, would finally dispel the persistent theological argument for the “strong anthropic principle”: the idea that the laws of physics were designed by God to make possible sentient life that could apprehend and worship Him (i.e. humans). To my mind, that argument is the last redoubt of a natural theology that’s been eroded to virtually nothing by science.

Unfortunately, multiverses may well be impossible to observe, even though they fall naturally out of existing theories of physics. Some physicists, like Paul Davies, claim that multiverses were concocted by physicists solely to dispel the idea of God, but they’re dead wrong. It’s a serious idea that’s been around for a while.

5. Are there multiverses?

Inflation is naturally chaotic. Bubbles form in the expanding universe, each developing into a big or small bang, perhaps each with different values for what we usually call the constants of nature. The inhabitants (if any) of one bubble cannot observe other bubbles, so to them their bubble appears as the whole universe. The whole assembly of all these universes has come to be called the “multiverse.”

These bubbles may realize all the different solutions of the equations of string theory. If this is true, then the hope of finding a rational explanation for the precise values of quark masses and other constants of the standard model that we observe in our big bang is doomed, for their values would be an accident of the particular part of the multiverse in which we live. We would have to content ourselves with a crude anthropic explanation for some aspects of the universe we see: any beings like ourselves that are capable of studying the universe must be in a part of the universe in which the constants of nature allow the evolution of life and intelligence. Man may indeed be the measure of all things, though not quite in the sense intended by Protagoras.

What better way to spend a lazy Sunday than contemplating the mysteries of the cosmos?

Here’s a picture I took of Steve and Alex Rosenberg at the “Moving Naturalism Forward” meeting about a year ago:

Steve and Alex

Famous physicists appear in film using cosmology to prove God

February 24, 2013 • 6:55 am

UPDATE: I’ve heard from Dr. Randall, who objected to my characterization of her as an “atheist.” I apologize for that and add the correction she wishes to make:

“. . . I rarely say I’m an atheist–I say I’m a nonbeliever. I actually think it’s a stupid word.
(Do we have a word for non-most things? It’s not an active process.)

I’d like that corrected.”

_______________

 

Last year a film came out that I just became aware of (h/t to Mike M.): “Cosmic Origins: The Scientific Evidence of Creation“.  It’s pretty much a put-up job for God, narrated by Fr. Robert Spitzer, religious philosopher, Jesuit priest,  former president of Gonzaga University, and author of New Proofs for the Existence of God. The synopsis and video clips (see below) suggest that it’s the standard boilerplate argument for “fine tuning” of the universe as evidence for God. It also throws in the cosmological argument: the universe could not have created itself, so goddidit.  Do these people even know physics? Here’s part of the blurb:

Picture 1

And this clip, a trailer for the movie, makes the God connection palpably clear:

The genial Fr. Spitzer (aren’t these Catholic accommodationists always the most affable priests around?) says this (be prepared to cringe):

If from nothing only nothing comes, and the universe came into existence, the universe, when it was nothing, could NOT have created itself—because it was nothing. Something else—not the universe—something else would have had to have done that. And that something else would have to transcend the universe.

I wonder what that “something else” is? And who created the “something else”?

I love the confident pronouncement that the universe could not have created itself. And these people are asking scientists to be humble?

What struck me, though, was this list of people appearing in the film:

Picture 2

Well,  Polkinghorne and Heller are Templeton flaks, Owen Gingerich is well known as a religious apologist, and Jennifer Wiseman is an evangelical Christian who heads the Templeton-funded Dialogue on Science, Ethics and Religion (DoSER) at the American Association for the Advancement of Science (AAAS).  (Many of you subscribe to Science, the AAAS magazine, so be aware that your organization is afflicted by this religious cancer, which, among other things, sponsored a “holiday lecture” by Denis Alexander, physicist, evangelical Christian, and head of Cambridge’s odious Faraday institute, also funded by Templeton. Sense some commonality to all this?)

But Arno Penzias and Lisa Randall? I had to look up Penzias’s views, and it turns out that he’s not only a religious Jew, but has suggested that the elegance of the universe bespeaks the glory of God. A report/interview from Ceio (link above) says this:

In connection with the Big Bang theory and the issue of the origin of our highly ordered universe, on March 12, 1978, Dr. Penzias stated to the New York Times:

“The best data we have are exactly what I would have predicted, had I had nothing to go on but the five books of Moses, the Psalms, the Bible as a whole.” (Penzias, as cited in Bergman 1994, 183; see also Brian 1995, 163).

Arno Penzias’ research into astrophysics has caused him to see “evidence of a plan of divine creation” (Penzias, as cited in Bergman 1994, 183).

In an interview published in the scientific anthology The Voice of Genius (1995), Dr. Penzias says:

“Penzias: The Bible talks of purposeful creation. What we have, however, is an amazing amount of order; and when we see order, in our experience it normally reflects purpose.

Brian: And this order is reflected in the Bible?

Penzias: Well, if we read the Bible as a whole we would expect order in the world. Purpose would imply order, and what we actually find is order.

Brian: So we can assume there might be purpose?

Penzias: Exactly. …This world is most consistent with purposeful creation.” (Penzias, as cited in Brian 1995, 163-165).

Randall is an avowed atheist, but has gone back and forth on accommodationism.  In a 2009 comment comment on the Edge website, when several public intellectuals were asked to react to my New Republic piece on the incompatibility of science and faith, Randall was an explicit accommodationist.  After describing how she met a science-friendly actor on a plane who nevertheless rejected evolution, Randall said this:

This reinforced for me why we won’t ever answer the question that’s been posed. Empirically-based logic-derived science and faith are entirely different methods for trying to approach truth. You can derive a contradiction only if your rules are logic. If you believe in revelatory truth you’ve abandoned the rules. There is no contradiction to be had.

Randall’s defense of a NOMA hypothesis was handily eviscerated by Sam Harris in a subsequent comment:

I am confident that Randall’s airplane adventure will mark a turning point in our intellectual discourse. Not only has she resolved all the contradictions between science and religion (and magic, voodoo, UFO cults, astrology, Tarot, palmistry, etc.), she has reconciled apparently conflicting religions with one another. Hindus worship a multiplicity of gods; Muslims acknowledge the existence of only one, and believe that polytheism is a killing offense. Do Hinduism and Islam conflict? Only “if your rules are logic.” Just as paths ascending a mountain slope can seem discrepant at the mountain’s base, and yet once we stand upon the summit, we find that all routes have led to the same destination—so it will be with every exercise of the human intellect! The Summit of Truth awaits, my friends. Simply pick your path…

On the other hand, reader Bob Carlson notes that, in Randall’s latest book, Knocking on Heaven’s Door, she takes a completely opposite stance:

[A]ny religious scientist has to face daily the scientific challenge to his belief. The religious part of your brain cannot act at the same time as the scientific one. They are simply incompatible.

And yet she appears in a movie that explicitly uses scientific “evidence” to prove God. I presume she wasn’t aware of this movie’s aim when she was approached to help with it, but, given her atheism and latest statement on incompatibility, I’d suggest that she might want to publicly disclaim the film.

At any rate, this humorous blurb appears on the film’s website.

Picture 1

Meterorite explodes over Russia

February 15, 2013 • 10:28 am

According to many venues, including our own Chicago Tribune, a meter exploded over Russia this morning, scattering hot debris and injuring many people:

CHELYABINSK, Russia — A meteor streaked across the sky and exploded over central Russia on Friday, sending fireballs crashing to earth that shattered windows and damaged buildings, injuring more than 500 people.

People heading to work in Chelyabinsk heard what sounded like an explosion, saw a bright light and then felt a shockwave, according to a Reuters correspondent in the industrial city 950 miles east of Moscow.

The fireball, travelling at a speed of 19 miles per second according to Russia’s space agency Roscosmos, had blazed across the horizon, leaving a long white trail in its wake which could be seen as far as 125 miles away.

Car alarms went off, windows broke and mobile phone networks were interrupted. The Interior Ministry said the meteor explosion had caused a sonic boom.

“I was driving to work, it was quite dark, but it suddenly became as bright as if it was day,” said Viktor Prokofiev, 36, a resident of Yekaterinburg in the Urals Mountains.

“I felt like I was blinded by headlights,” he said.

No fatalities were reported, but President Vladimir Putin, who was due to host Finance Ministry officials from the Group of 20 nations in Moscow, told Emergencies Minister Vladimir Puchkov to help those affected.

And, of course, capitalism comes to Russia:

Despite warnings not to approach any unidentified objects, some enterprising locals were hoping to cash in.

“Selling meteorite that fell on Chelyabinsk!,” one prospective seller, Vladimir, said on a popular Russian auction website. He attached a picture of a black piece of stone that on Friday afternoon was priced at $49.46.

Here’s a new video if the meteor that has already gotten 105,000 views.

Neil deGrasse Tyson tilts back towards atheism, touts a purposeless universe

November 29, 2012 • 10:11 am

According to MinutePhysics, the Templeton Foundation asked astronomer Neil deGrasse Tyson to answer the question, “Does the universe has a purpose?” Now I’m not sure whether they paid him to answer (taking such money would, in my view, be offensive), but I don’t think they’ll like Tyson’s answer given in the short video below. (It’s illustrated with MinutePhysics’ drawings.) Tyson’s a wee bit on-the-fencey, but definitely suggests that creatures make their own purpose.

Give this a listen; it’s only 2.5 minutes long. And his answer, toward the end of the video, is pretty clear:

“So while I cannot claim to know for sure whether or not the universe has a purpose, the case against it is strong—and visible to anybody who sees the universe as it is, rather than as they wish it to be.”

If that’s not an explicit rejection of religion, I don’t know what is.

Tyson has risen again in my esteem, so long as he wasn’t paid by Templeton for this (and Templeton usually does pay for such answers).

h/t: Greg Mayer

Scientists debate philosophers and theologians at CERN—but why?

October 15, 2012 • 9:55 pm

Unlike some of my readers, I don’t dismiss all academic philosophy as worthless. The discipline imparts the tools of logic and throught that can clarify questions and bring contradictions to light. I think it’s of most value in illuminating (but not necessarily solving) ethical problems and dilemmas, but of less value for working scientists.

But in an ongoing meeting in Geneva described by the BBC, its value would seem to be nil (the CERN-sponsored conference, which ends tomorrow, is called “The Big Bang and the interfaces of knowledge: towards a common language?“)*

Worse: at this conference philosophy is rendered even more ineffectual by diluting it with theology—a form of intellectual homeopathy. As the BBC reports:

Some of Europe’s most prominent scientists have opened a debate with philosophers and theologians over the origins of everything.

The event, in Geneva, Switzerland, is described as a search for “common ground” between religion and science over how the Universe began.

It will focus on the Big Bang theory.

The conference was called by Cern, the European Organization for Nuclear Research, in the wake of its Higgs boson discovery.

And, at the outset, the the theologian-philosophers parade their hauteur, trying to tell physicists that they’re doing it rong (Pinsent, mentioned below, has degrees in physics and philosophy and is on the theology faculty at Oxford):

The first speaker at the conference was Andrew Pinsent, research director of the Ian Ramsey Centre for Science and Religion at Oxford University.

He said that science risked “trying to turn society into a machine” if it did not engage with religion and philosophy.

“Science in isolation is great for producing stuff, but not so good for producing ideas,” he told the BBC.

“Einstein began by asking the kinds of questions that a child would ask, like what would it be like to ride on a beam of light.”

That, Dr Pinsent said, was what science should return to.

Not so good for producing ideas? That claim is what comes out of the south end of a horse facing north.  First of all, many scientists do engage with religion and philosophy, but I suspect the kind of engagement Pinsent wants is not debate (as occurs on this site), but mutual back-patting.

And in the case of this conference, that engagement is useless. What do theologians, or philosophers for that matter, have to say about the origin of the universe that’s of any value to scientists? Any “philosophizing” about things like multiverses can be done perfectly well by scientists on their own.

The stuff about “turning society into a machine” is alarmist hype; nothing like that would happen without the vaunted “dialogue”, even if all scientists buried themselves in their labs like hermit.

Finally, who the hell does Pinsent think he is telling scientists that we’re not coming up with new ideas in the right way? Isn’t string theory a remarkable imaginative achievement, even if we can’t yet test it?  So is the idea of multiverses; and Lee Smolin‘s theory of “cosmological natural selection” is highly original, even if it proves to be wrong.

Sadly, the BBC article doesn’t report any dissent, or pushback, by scientists. It reports only annoying statements by philosopher and theologians, and one rump-osculating statement by the director of CERN:

Prof Rolf Heuer, director of Cern, explained that the Higgs results provided a “deeper insight and understanding of the moments after the Big Bang”.

He added that he hoped, by the end of the conference, that delegates from very different backgrounds would be able to “start to discuss the origin of our Universe”.

Yeah, but only scientists will be able to make progress in understanding the origin of our universe.  The rest of the attendees will stare at their navels and aver that scientists can’t answer the Really Big Questions, like why there was a Big Bang:

Co-organiser Canon Dr Gary Wilton, the Archbishop of Canterbury’s representative in Brussels, said that the Higgs particle “raised lots of questions [about the origins of the Universe] that scientists alone can’t answer”.

“They need to explore them with theologians and philosophers,” he added.

No they don’t. That’s a waste of time, and gives theologians and philosophers unwarranted credibility in what is a purely scientific problem. That looks good on their c.v.s, but not so good on the physicists’. As scientists’ efforts continue to shrink the bailiwicks of both philosophy and, especially, theology, practitioners of these disciplines are desperate to retain a seat at the Big Table and anxious to show that they, too, have something to contribute to the progress of science.

The thing is, they don’t. Philosophy of science is a meta-discipline, which can analyze the sociology of our field, often in enlightening ways, but hasn’t, as far as I can see, contributed to science’s progress. Yes, insofar as scientists themselves ruminate about the meaning of their achievements (philosophers love to count this as philosophy), that leads to progress. But with few exceptions (for me, Dennett and Kitcher, because they know a lot about evolution), formal academic philosophy of science has not advanced science itself. Most honest philosophers of science will admit this. And of course theology is useless for advancing knowledge—it only impedes science by confusing the public and raising “science stoppers” like the fine-tuning argument and the claim that morality implies a God.

This is what you get when a conference is co-organized by a physicist and a representative of the Archbishop of Canterbury: a few shreds of meat floating around in a bowl of porridge:

The organisers are expecting some disagreements during the three-day event.

For example, one of the speakers, Prof John Lennox from Oxford University, has been an outspoken critic of atheist scientists in the past.

Most recently, he took issue with Prof Stephen Hawking’s assertion that God did not create the Universe.

In an article in the Daily Mail, he said that he was certain that Prof Hawking was wrong.

Prof Lennox wrote: “When Hawking argues, in support of his theory of spontaneous creation, that it was only necessary for ‘the blue touch paper’ to be lit to ‘set the universe going’, the question must be: where did this blue touch paper come from? And who lit it, if not God?”

Well, maybe it lit itself, Dr. Lennox? Have you ruled out that possibility?

But the theologian-philosphers press on, like kids who beg to sit at the adults’ table at Thanksgiving:

Dr Wilton, though, said he was hopeful that “scientists, theologians and philosophers alike might gain fresh insights from each other’s disciplines”

“This is such an exciting conference,” he told the BBC.

For him, maybe. He gets the cachet of getting to debate real scientists and pretending that he has something meaningful to say to them. But the conference isn’t so exciting for physicists.

And since when did the estimable scientific organization CERN start acting like the Templeton Foundation?

h/t: John, Matthew Cobb

________

*The answer is “no.” You can download a pdf of the conference program here; warning—it’s infuriating.

More apologetic gymnastics: John Haught explains why Christianity comports with cosmology

September 10, 2012 • 11:53 am

Sorry to inflict this on you, but really, you have to keep up with Sophisticated Theology™.  This excerpt is from our old friend John Haught, in his article “Christianity and human evolution” in The Blackwell Companion to Science and Christianity (pp. 295-305).

Halfway through this 600-page tome, whose editors J. B. Stump and A. G. Padgett promised would not be “a work defending or promoting Christian faith,” (p.xix), I see that they have misled us. At least 80% of the pieces try to reconcile science and Christianity (Sean Carroll’s essay is a rare exception).  It is shameful that Blackwell published such a volume.  Simon Conway Morris’s piece on convergence and Christianity, for example, is followed by an essay by Stephen C. Meyer of the Discovery Institute, pushing his discredited theory that evolution cannot produce “specified information” without the intervention of an intelligent designer.

In the “Evolution” section, John Haught comes onstage to show us once again how evolution not only comports with Christianity, but is exactly what we would expect if God were to create according to His nature. Haught once again makes a theological virtue from a scientific necessity:

“According to many Christian evolutionists, Darwin’s new science now makes it possible to think of God’s power to create as more impressive than ever.  A creator who brings into being a world that in turn gives new kinds of being from out of its original resourcefulness is certainly more impressive than a hypothesized ‘designer’ who molds and manages everything in the world directly.” (p. 296).

I wonder why the Bible didn’t tell us that? And is that really so? Wouldn’t a God who could make a frog or a gazelle or a Venus flytrap ex nihilo be more impressive than one who just allowed an original form of life to evolve unchecked?

Anyway, I wanted to highlight the same virtue that Haught makes out of the necessity of the Big Bang:

“It may be instructive, therefore, to locate the question of human significance within the framework of the newly revealed cosmic drama.  Christian theology may now ask what human evolution means not only in conversation with biology but also with cosmology.”

. . . Many scientists* have now concluded that the Bing bang universe has been pregnant with life and mind from its very inception 14 billion years ago. Contrary to what materialist or ‘physicalist’ philosophies of nature have traditionally held, the stuff of the universe has never been essentially mindless. The emergence of being endowed with the capacity to understand, reflect, and decide, therefore, really begins during the first microsecond of the universe’s existence.  Christianity’s declaration that human beings have been specially endowed by the Creator with a unique significance and a special vocation within the total scheme of things is at least logically consistent with contemporary cosmology.” (p. 301)

I love that weasel phrase “logically consistent”!

Likewise, the island of Manhattan has never been without skyscrapers, for the emergence of such tall beings endowed with the capacity to hold many humans on a small footprint of space really began at the first instant an early hominin decided to live in a cave.
____________

*There are those “many scientists” again! I wonder who they are. . .