On Saturday, I slept in a little, to get rid of the last vestiges of jet-lag, and got up at 9am, showered, dressed, grabbed a book and headed out to Lygon Street, half a block from my apartment. I spent a lovely leisurely morning in the university neighborhood, getting cappuccino and croissants at Thresherman’s Bakehouse, followed by a wander around the stores, and a second cappuccino at another cafe.

Then I dropped by a local wine merchant to pick out something for my apartment. I am very partial to Australian Shiraz, and here my choices were so varied that it took me forty minutes to pick out something, and even then, I felt that it was essentially a rather random choice, within my chosen price range. On the way back, I stuck my head into an internet cafe to check email and comments on Cosmic Variance, and then deposited the wine back at my apartment before heading out to meet my good friend and one of my hosts here - Ray Volkas - who treated me to a wonderful Saturday in Melbourne.

We started with a very nice lunch at Chocolate Buddha, a cute Japanese restaurant in Federation Square, across from the famous Flinders Street Station. After that, we took a long walk through town, stopping for an excellent espresso at one of the countless excellent coffee shops, and ending up at the Melbourne Observation Deck, from which we could see the ocean, the whole of downtown, Melbourne Cricket Ground, the roads along which the grand prix is held, and lots more.

Next stop was the Crown Casino. I only really had time to take a quick look at the poker room (where 2005 World Series of Poker winner Joseph Hachem played occasionally, I believe), but there is a distinct possibility that I will find time to go back and play for a while before leaving Melbourne. Ray and I had a nice drink in the atrium bar at the casino, before resuming our tour with a quick walk through the National Gallery of Victoria, which was hosting the final day of a wonderful Picasso exhibition.

We decided not to queue up to see the exhibit, opting instead to head to the Australian Centre for Contemporary Art, which is housed in a remarkable building, constructed from rusted metal (at least in appearance) and in which we strolled through a (mostly) thought-provoking exhibit of the work of Gillian Wearing.

Modern art is notorious for making one thirsty, and, since we had passed one of the most famous pubs in Melbourne - Young and Jackson’s - on our way into the city center, we walked back across town and stopped in for a couple of pints there. Pubs are something I miss a lot about my home country and it is fun to experience something very close, at least as far as ambience goes, so far away from home.

Before dinner we decided to drop in to The Gin Palace for a spectacularly good martini (OK, I know this is sounding like a boozy day, but it was the weekend, and some ways to see new cities are just so much more fun than others). This gave us just the kick required to get us over to Chinatown, for dinner at The Spicy Fish where we had the famous entree of the same name - a wonderfully prepared dish that is probably the best food I’ve had in Melbourne so far.

No “lads day about town” is complete without a nightcap, and so we headed to the Melbourne Supper Club, to finish off the evening with an after dinner drink (Madeira for me) and a Cuban cigar (that’s right America - a filthy communist cigar - aaaghhhh).

A truly wonderful day, full of culture, fine food, fine drinks, fine cigars, and great company. I’m already a fan of Melbourne, with two weeks left to enjoy its other pleasures.

Nobels were not the only prizes announced last week - some recipients of the 2007 American Physical Society (APS) prizes were notified as well. And our very own Stan Brodsky of the SLAC theory group has been awarded the 2007 J. J. Sakurai Prize for Theoretical Particle Physics! Congratulations Stan! We couldn’t be prouder.

The Sakurai Prize was established in 1984 in memorium to J.J. Sakurai with the purpose of recognizing and encouraging outstanding achievement in particle theory . It is normally awarded for theoretical contributions made at an early stage of the recipient’s research career.

The citation that will appear on Stan’s certificate is:

For applications of perturbative quantum field theory to critical questions of elementary particle physics, in particular, to the analysis of hard exclusive strong interaction processes.

Stan’s career has been devoted to the understanding of QCD (Quantum Chromodynamics) which is the theory behind the force that describes the strong interactions of quarks and gluons. Stan has been prolific, with 441 listings on the HEP SPRIES database. As of 2004, these papers gathered a total of roughly 20,000 citations, putting Stan 12th on the list of all-time top-cited HEP theory authors.

Stan wrote two seminal papers during his early career which formed the basis for this award. The first was co-authored by Glennys R. Farrar in 1973 with the title Scaling Laws At Large Transverse Momentum (sorry, you have to be registered or at a registered institution to get the full article from Physical Review). This was back in the day when quarks and gluons were just discovered and the theory of their interactions and their binding into hadronic states was being developed. Stan and Glennys showed that the probability of scattering between two mesons and/or baryons, A+B to C+D, is proportional to (or scales with) the total number of constituent particles bound inside the inital and final hadronic states A, B, C, and D. They went on to demonstrate that this scaling could be understood in the context of renormalizable theories, thus providing further evidence that QCD is renormalizable. The process of renormalization is a technique for handling divergences or infinities in a theory so that the theory can make testable, finite predictions. Stan and Glennys submitted this work just two months after the famous papers on asymptotic freedom by the 2004 Nobel prize winners Gross, Wilczek, and Politzer appeared in print.

Stan’s second early seminal work, entitled Exclusive Processes In Perturbative Quantum Chromodynamics, was co-authored with Peter Lepage in 1980. Here, they performed a systematic investigation of the scattering behavior of hadrons. They proved that at short distances these scatterings were dominated by interactions between the constituent quarks and gluons and that the resulting scattering rate was a rigorous prediction of QCD. In other words, at high enough energies (corresponding to short distances), the observed scattering between hadrons is actually a result of scattering between the constituent particles within the hadrons with a probability predicted by QCD. This is something that every particle theorist learns in kindergarten, takes for granted today, and provides the basis for all Tevatron and LHC calculations.

The prize will be presented to Stan at a special ceremonial session at the APS 2007 April meeting in Jacksonville, FL.

Last night I heard a rather lovely program. It was on the NPR program called “Radio Lab”, and this one was all about music and language. You can hear the whole thing by listening to the archive at this link. Among my favourite things was the first piece, right at the beginning of the program, based upon the work of Diana Deutsch, who specializes in the psychology of music. They talk about (and play you a sample from) a time when she recorded a spoken phrase and “looped it”, so that it plays again and again. After a while of listening to this (I remember noticing this myself in other contexts), that spoken phrase actually takes on a musical characteristic! It is amazing how fast and sharp the transition is, actually. Go listen to the first part of the show to hear it yourself.

The most striking part is then to go back to the original sentence and and hear that spoken phrase in context. Once your brain has hooked itself on the idea that it is a sung phrase and not a spoken phrase, listening to the sentence is normal until you get to that phrase and then it sounds like she is bursting into song!

This opens up a very interesting discussion on the whole business of language and music, and their intersection. What is music, really? How context dependent is it?

Diana Deutsch has done some research on “tone languages”, for example - languages Continue reading ‘Music and Language’

Well, I’ve finally arrived in Melbourne. I left Syracuse on a 2:25pm flight on Monday, landed in Dulles an hour later, waited there for a couple of hours, took a 4.5 hour flight to LA, connected to a 14 hour flight to Sydney, and then, finally, caught another 1.5 hour flight to Melbourne.

Despite a number of possible pitfalls developing along the way (which I won’t bore you with here), the flight actually turned out to be hassle-free, and I did get to weigh in on the side of all that is good and right (you know - science) towards the end of it.

On the long haul flight from LAX to Melbourne, I ended up in a row of three people. One of these was a true Aussie caricature. A pretty nice guy, for sure, but particularly if you’re a Brit, you’ll know exactly what I mean by this. It was the equivalent of meeting an Englishman wearing Union Jack boxer shorts, with a can of beer in one hand and a bag of chips in the other. But it was the other seatmate who turned out to be the one I ended up discussing science with.

For almost the entire flight we didn’t really exchange words, since either one or the other of us was sleeping, or I had my isolating earphones on and wasn’t up for chatting. However, as the flight came to a close I had to crack open my laptop to look up some immigration information, and when he saw the sciencey stuff splashed all over the screen he asked what I did. When I told him, he then asked me if I knew anything about zero-point energies. I told him that I did indeed, but, before I could brighten up at the thought of having a science enthusiast next to me, he then said

“I use those in my treatment methods”

At times like this a healthily populated decision tree pops up in one’s head. Do you smile politely and say something bland and pop the earphones back in? If not, and you engage the person in a discussion, how do you ensure that it doesn’t go off the rails? Do you have an exit strategy? What is to be gained by each of these possibilities?

In this case, my decision was simplified considerably by the fact that the plane was due to land in an hour, and that would provide a natural end to the discussion, whichever way it went.

So I asked him what he meant by that and he proceeded to tell me that he’d had a career in computing, but had been able to develop this amazing new treatment for asthma, cancer, and pretty much anything else that ails you, which involves controlling your emotions (there was something in there about tapping into the zero-point energy of all matter, but that’s as close as I got to seeing where all that would come in).

He told me that his treatment, or method, works. Rather than respond with the traditional British Rationalist reply - “What a load of old bollocks!”, I instead I asked him what he meant by “work”, and he said that he meant that he has personally seen it cure people of cancer. I asked him whether there had been any double blind trials involving statistically significant numbers of patients, and, to my surprise, he said that there hadn’t been (OK, that bit wasn’t surprising) and that he realized that was what it would take for his method to be accepted and that he was hoping someone would eventually come forward with the funds to support that.

He was really very sincere and pleasant, but obviously deeply misguided at best (please don’t arrive in the comments section championing this kind of nonsense). But what kept getting at me was that he would good-naturedly listen to what I said, agree with it mostly, and then keep saying that the method clearly worked. When I continued to challenge him on this definition, he then said that he didn’t have the technical knowledge to go up against someone like me (a scientist), but he had practiced the technique and seen it work. He also came out with many of the old favorites, like “people used to think that the world was flat, until they dared to go and find out if it was true”, to which I gave him back the old “it’s great to keep an open mind, of course, but not one so open as your brains fall out” (Snap!).

Anyway, now that I have a computer again, I’ve been able to look this guy up and it turns out his process has a web site called: The ZPoint process for instant Emotional Healing. Take a look - it is all that you may have imagined it to be from the above description of the conversation. Try to resist the temptation to bang your head against a wall after visiting the site - trust me, it hurts.

Melbourne is great. I’ll be posting more soon about the department, the city, the people, and my time here. In the meantime, keep your eyes open wide for those cranks and charlatans.

Chet Raymo, who for years wrote very enjoyable science columns for the Boston Globe, has a blog called Science Musings that is well worth checking out. He posts today about an article in the Atlantic, derived in turn from this report, that compares the mathematical performance of U.S. students to those in various Asian countries.

(I wonder if the Australian scores were collected before or after Mark got there?) Now, self-confidence is a good thing, all else being equal. But being educated well is also a good thing. It’s no secret that we don’t train our teachers well, provide schools with proper resources, or challenge our students enough in the classroom. Maybe there’s something we can learn from what’s going on in Asia.

The Large Hadron Collider accelerates protons to an energy of 7000 GeV, which is pretty impressive. (A GeV is a billion electron volts; the energy in a single proton at rest, using E=mc², is about 1 GeV.) But it requires a 27-kilometer ring, and the cost is measured in billions of dollars. The next planned accelerator is the International Linear Collider (ILC), which will be similarly grand in size and cost. People have worried, not without reason, that the end is in sight for experimental particle physics at the energy frontier, as it becomes prohibitively expensive to build new machines.

That why it’s great news that scientists from Lawrence Berkeley Labs and Oxford have managed to accelerate electrons to 1 GeV (via Entropy Bound). What’s that you say? 1 GeV seems tiny compared to 7000 GeV? Yes, but these electrons were accelerated over a distance of just 3.3 centimeters, using laser wakefield technology. You can do the math: if you could simply scale things up (in reality it’s not so easy, of course), you could reach 10,000 GeV in a distance of about a hundred meters.

The LHC and the ILC won’t be the end of particle physics. Even the Planck scale, 10¹⁸ GeV, isn’t all that big. In terms of mass-energy, it’s only one millionth of a gram. The kinetic energy of a fast car is of order 10¹⁶ GeV, close to the traditional grand-unification scale. (Why? Kinetic energy is mv²/2, but let’s ignore factors of order unity. The speed of light is c = 200,000 miles/sec = 7*10⁸ miles/hour. So a car going 70 miles/hour is moving at 10^-7 the speed of light. The mass of a car is about one metric ton, which is 1000 kg, which is 10⁶ grams, and one gram is 10²⁴ GeV. So a car is 10³⁰ GeV. [Or you could just happen to know how many nucleons/car.] So the kinetic energy is that mass times the velocity squared, which is 10³⁰*(10^-7)² GeV = 10¹⁶ GeV.)

The trick, of course, is getting all this energy into a single particle, but that’s a technology problem. We’ll get there.

The Nobel Prize in Physics has been awarded to John Mather and George Smoot, for their discovery using the COBE satellite of temperature anisotropies in the cosmic microwave background. (Update: To be more accurate, Mather won the prize for measuring the blackbody spectrum of photons, announced in 1990; Smoot won it for measuring the anisotropies, announced in 1992. Thanks to Ned Wright for pointing out my sloppiness.) These tiny fluctuations in temperature provide a high-precision snapshot of what the universe was like 380,000 years after the Big Bang. They originate in density fluctuations that grow into large-scale structure today, and subsequent careful examination of the properties has revealed a tremendous amount about our universe. It’s a very well-deserved Nobel, which was top on my list of potential cosmology prizes back in May:

The 1992 observation of CMB anisotropies by NASA’s COBE satellite was the first step in a revolution in how cosmology is done, one that has come to dominate a lot of current research. Subsequent measurements by other experiments have obviously led to great improvements in precision, and most importantly extended our understanding of the anisotropies to smaller length scales, but I think the initial finding deserves the Nobel. So to whom should the prize be awarded? On purely scientific grounds, it seems to me that there was an obvious three-way prize that should have been given a while ago, to David Wilkinson, John Mather, and George Smoot. Wilkinson was the grandfather of the project, and was the leading CMB experimentalist for decades. Mather was the Project Manager for the satellite itself (as well as the Principal Investigator for the FIRAS instrument that measured the blackbody spectrum), while Smoot was the PI for the DMR instrument that actually measured the anisotropies. Unfortunately, Wilkinson passed away in 2002. Another complicating factor is that there were various intra-collaboration squabbles, leading to books by both Smoot and Mather that weren’t always completely complimentary toward each other. Still, background noise like that shouldn’t get in the way of great science, and these guys definitely deserve the Nobel.

When the results were announced in 1992, I was a fourth-year graduate student at the Center for Astrophysics at Harvard. Somehow, despite great attempts at secrecy, Bill Press had received a leak about the upcoming announcement, and had told some of us at CfA. The next day I went to the Physics colloquium and was the first to spread the news to some of the famous physicists chatting in the tea room, like Sidney Coleman and Roman Jackiw. My first feeling of being a cosmology insider.

It was a funny discovery, in the sense that most everyone expected that it would come (COBE was designed to do exactly this), and nevertheless ended up revolutionizing the field. The simplest measure of this was the arrival of an entire generation of smart young theoretical cosmologists who got their Ph.D.’s in the 1990’s working on the implications of the CMB anisotropies. Whenever we learn alot about the universe, of course, we also start ruling out interesting ideas; these days, nobody proposing a new cosmological scenario will be taken seriously unless their model is compatible with the microwave background.

Congratulations to John and George for ushering in the Golden Age of Cosmology!

I was asked to review Lee Smolin’s The Trouble With Physics by New Scientist. The review has now appeared, although with a couple of drawbacks. Most obviously, only subscribers can read it. But more importantly, they have some antiquated print-journal notion of a “word limit,” which in my case was about 1000 words. When I started writing the review, I kind of went over the limit. By a factor of about three. This is why the Intelligent Designer invented blogs; here’s the review I would have written, if the Man hadn’t tried to stifle my creativity. (Other reviews at Backreaction and Not Even Wrong; see also Bee’s interview with Lee, or his appearance with Brian Greene on Science Friday.)

——————————————————————

It was only after re-reading and considerable head-scratching that I figured out why Lee Smolin’s The Trouble With Physics is such a frustrating book: it’s really two books, with intertwined but ultimately independent arguments. One argument is big and abstract and likely to be ignored by most of the book’s audience; the other is narrow and specific and part of a wide-ranging and heated discussion carried out between scientists, in the popular press, and on the internet. The abstract argument — about academic culture and the need to nurture speculative ideas — is, in my opinion, important and largely correct, while the specific one — about the best way to set about quantizing gravity — is overstated and undersupported. It’s too bad that vociferous debate over the latter seems likely to suck all the oxygen away from the former.

Fundamental physics (for want of a better term) is concerned with the ultimate microscopic laws of nature. In our current understanding, these laws describe gravity according to Einstein’s general theory of relativity, and everything else according to the Standard Model of particle physics. The good news is that, with just a few exceptions (dark matter and dark energy, neutrino masses), these two theories are consistent with all the experimental data we have. The bad news is that they are mutually inconsistent. The Standard Model is a quantum field theory, a direct outgrowth of the quantum-mechanical revolution of the 1920’s. General relativity (GR), meanwhile, remains a classical theory, very much in the tradition of Newtonian mechanics. The program of “quantum gravity” is to invent a quantum-mechanical theory that reduces to GR in the classical limit.

This is obviously a crucially important problem, but one that has traditionally been a sidelight in the world of theoretical physics. For one thing, coming up with good models of quantum gravity has turned out to be extremely difficult; for another, the weakness of gravity implies that quantum effects don’t become important in any realistic experiment. There is a severe conceptual divide between GR and the Standard Model, but as a practical matter there is no pressing empirical question that one or the other of them cannot answer.

Quantum gravity moved to the forefront of research in the 1980’s, for two very different reasons. One was the success of the Standard Model itself; its triumph was so complete that there weren’t any nagging experimental puzzles left to resolve (a frustrating situation that persisted for twenty years). The other was the appearance of a promising new approach: string theory, the simple idea of replacing elementary point particles by one-dimensional loops and segments of “string.” (You’re not supposed to ask what the strings are made of; they’re made of string stuff, and there are no deeper layers.) In fact the theory had been around since the late 1960’s, originally investigated as an approach to the strong interactions. But problems arose, including the unavoidable appearance of string states that had all the characteristics one would expect of gravitons, particles of gravity. Whereas most attempts to quantize gravity ran quickly aground, here was a theory that insisted on the existence of gravity even when we didn’t ask for it! In 1984, Michael Green and John Schwarz demonstrated that certain potentially worrisome anomalies in the theory could be successfully canceled, and string mania swept the particle-theory community.

In the heady days of the “first superstring revolution,” triumphalism was everywhere. String theory wasn’t just a way to quantize gravity, it was a Theory of Everything, from which we could potentially derive all of particle physics. Sadly, that hasn’t worked out, or at least not yet. (String theorists remain quite confident that the theory is compatible with everything we know about particle physics, but optimism that it will uniquely predict the low-energy world is at a low ebb.) But on the theoretical front, there have been impressive advances, including a “second revolution” in the mid-nineties. Among the most astonishing results was the discovery by Juan Maldacena of gauge/gravity duality, according to which quantum gravity in a particular background is precisely equivalent to a completely distinct field theory, without gravity, in a different number of dimensions! String theory and quantum field theory, it turns out, aren’t really separate disciplines; there is a web of dualities that reveal various different-looking string theories as simply different manifestations of the same underlying theory, and some of those manifestations are ordinary field theories. Results such as this convince string theorists that they are on the right track, even in the absence of experimental tests. (Although all but the most fervent will readily agree that experimental tests are always the ultimate arbiter.)

But it’s been a long time since the last revolution, and contact with data seems no closer. Indeed, the hope that string theory would uniquely predict a model of particle physics appears increasingly utopian; these days, it seems more likely that there is a huge number (10⁵⁰⁰ or more) phases in which string theory can find itself, each featuring different particles and forces. This embarrassment of riches has opened a possible explanation for apparent fine-tunings in nature — perhaps every phase of string theory exists somewhere, and we only find ourselves in those that are hospitable to life. But this particular prediction is not experimentally testable; if there is to be contact with data, it seems that it won’t be through predicting the details of particle physics.

It is perhaps not surprising that there has been a backlash against string theory. Lee Smolin’s The Trouble With Physics is a paradigmatic example, along with Peter Woit’s new book Not Even Wrong. Both books were foreshadowed by Roger Penrose’s massive work, The Road to Reality. But string theorists have not been silent; several years ago, Brian Greene’s The Elegant Universe was a surprise bestseller, and more recently Leonard Susskind’s The Cosmic Landscape has focused on the opportunities presented by a theory with 10⁵⁰⁰ different phases. Alex Vilenkin’s Many Worlds in One also discusses the multiverse, and Lisa Randall’s Warped Passages enthuses over the possibility of extra dimensions of spacetime — while Lawrence Krauss’s Hiding in the Mirror strikes a skeptical note. Perhaps surprisingly, these books have not been published by vanity presses — there is apparently a huge market for popular discussions of the problems and prospects of string theory and related subjects.

Continue reading ‘The Trouble With Physics‘

Given the distressing and depressing news emanating from the US Congress the past couple of days, it’s time for a slightly more upbeat post. A success story, if you will. A serious problem that has been solved. Yes folks, it’s come to this:

CV readers may recall the trauma suffered a few weeks ago due to a roof rat invading my tomato crop. Well, the roof rat (and his friends) were easily dealt with (naturally, they are now all dead rats). But the squirrels turned out to be a rather serious problem. One came and quickly told all his/her friends. Seems they considered my tomatoes to be quite tasty. Not any more….they can find another restaurant!

Ha - foiled them critters! (I must admit it is real fun to watch them try to get into the cages!) And, my tomato yield has drastically improved.

For all you squirrel lovers out there - note that no squirrels were actually harmed in the cage building process.

I’ve been absent for a week or so, and will be for a few days more. However, before I hop on a plane, I thought I’d quickly comment on what a remarkable week it has been for the constitution.

I hesitate slightly before continuing to write negative things about the government, because you see, I am now classified as someone who, despite paying large amounts in taxes, despite being married to an American, and hence having large numbers of extended family in the U.S., despite working for an American employer, and despite loving my “Mom”, enjoying baseball, and being partial to a nice slice of apple pie, can nevertheless be whisked away without a moment’s notice, and detained indefinitely, having no right to challenge my detention. I can, in essence, be disappeared by my own government. Yes, the passing of S. 3930 - “A bill to authorize trial by military commission for violations of the law of war, and for other purposes” - by a 65-34 Senate vote will be judged harshly by history, should there be any of us around to do the judging.

Hot on the heels of this disgusting, terrifying, embarrassing and deeply saddening piece of legislation, our leaders have now passed another absolute corker. While our troops are in Iraq, fighting, we are supposed to believe, against religious extremists who hate our democracy and freedoms, here at home plans are moving ahead to edge this much-touted democracy closer and closer to a theocracy, in which the religious (well, let’s be honest, Christians really, and only certain kinds of them at that) are a privileged class.

The most recent move in this direction is The Public Expression of Religion Act - H.R. 2679. This says, and I paraphrase, that while the constitution is the basis of American democracy, and applies to all citizens, you should get a break if you violate it to force your religion on someone. That is to say, breaking the law in the name of religion is less of a crime than breaking it if you are, say, hungry, or without shelter.

As Erwin Chemerinsky says in The Washington Post, this bill

… provides that attorneys who successfully challenge government actions as violating the Establishment Clause of the First Amendment shall not be entitled to recover attorneys fees. The bill has only one purpose: to prevent suits challenging unconstitutional government actions advancing religion.

Chemerinsky goes on to point out that

The attorneys’ fees statute has worked well for almost 30 years. Lawyers receive attorneys’ fees under the law only if their claim is meritorious and they win in court. Unsuccessful lawyers get nothing under the law. This creates a strong disincentive to frivolous suits and encourages lawyers to bring only clearly meritorious ones.

and concludes correctly that

Such a bill could have only one motive: to protect unconstitutional government actions advancing religion. The religious right, which has been trying for years to use government to advance their religious views, wants to reduce the likelihood that their efforts will be declared unconstitutional. Since they cannot change the law of the Establishment Clause by statute, they have turned their attention to trying to prevent its enforcement by eliminating the possibility for recovery of attorneys’ fees.

Well, on that sad note, and with my bile rising, I’m going to pack my bags. I’m off to Australia in the morning, for three weeks. I will be a Sir Thomas Lyle Fellow at the University of Melbourne, and plan to work hard and have a great time. I should be able to resume regular posting while there, so I’ll try to provide some discussion of physics (and food and wine) down under.

Three weeks is a long time in U.S. politics. I’ll be keeping my fingers crossed that, when I return, the passport control discussion doesn’t go like:

Agent: “Where have you been on this trip Sir?”
Me: “Australia”
Agent: “Was it business or pleasure Sir?”
Me: “Some of both”
Agent: “How long were you out of the country Sir?”
Me: “Twenty one days”
Agent: “One last question Sir; have you accepted Jesus Christ as your Lord and savior?”