Archive for Brian Schmidt

No more ripples?

Posted in Biographical, The Universe and Stuff with tags , , , on July 27, 2013 by telescoper

Well, that’s the Ripples in the Cosmos meeting in Durham over and done with, and I’m back in Newcastle for a few days before moving on to Edinburgh next week. I’m not sure I’ll be able to blog much over the next few days because my internet connectivity will be a bit limited.

Anyway, the meeting was very exciting, as you can tell from the picture showing me (with the beard) and Brian Schmidt (with the Nobel Prize):

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Yesterday it was my job to round off the meeting with some concluding remarks leading into a panel discussion. I have to admit that although the programme for the conference was clearly designed in order to generate provoke discussion, I was a little disappointed that so few people said anything controversial. I’ve long held that there are too many cosmologists willing to believe too much, and this was further evidence that the scepticism that is a necessary part of a healthy science has been replaced by widespread conformity, especially among the young; when I was a lad the students and postdocs were a lot more vocal at meetings than they are now. Perhaps this is characteristic of a change in culture of cosmology? To get a job nowadays it’s virtually essential to climb onto one of the big bandwagon projects, and to keep your place you have to toe the party line, refrain from rocking the boat, not speak out of turn, and avoid making ripples (That’s enough metaphors. Ed).

Anyway, I think there are still a great many things in modern cosmology we don’t understand at all, and I think a few more of the older generation should show the way by questioning things in public. In fact only got asked to do the concluding remarks because Jim Peebles was unable to come to the meeting. Jim’s an immensely distinguished physicist who has probably done more than any other living person to develop the standard cosmology, but he’s also never been afraid to play devil’s advocate. We need more like him, willing to articulate the doubts that too many of us feel the need to suppress.

It’s amazing how much progress we have made in cosmology over the last few decades, but we shouldn’t use that as an excuse to get complacent. Cosmology is about the biggest questions in science. That alone makes it an exciting subject to work in. It’s an adventure. And the last thing you want on an adventure is for the journey to be too comfortable.

Another Nobel Prize for Cosmology!

Posted in The Universe and Stuff with tags , , , , , , , on October 4, 2011 by telescoper

Just time in between teaching and meetings for a quick post on today’s announcement that the 2011 Nobel Prize for Physics has gone to Saul Perlmutter, Brian P. Schmidt and Adam G. Riess “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae.”

I’ve taken the liberty of copying the following text from the press release on the Nobel Foundation website

In 1998, cosmology was shaken at its foundations as two research teams presented their findings. Headed by Saul Perlmutter, one of the teams had set to work in 1988. Brian Schmidt headed another team, launched at the end of 1994, where Adam Riess was to play a crucial role.

The research teams raced to map the Universe by locating the most distant supernovae. More sophisticated telescopes on the ground and in space, as well as more powerful computers and new digital imaging sensors (CCD, Nobel Prize in Physics in 2009), opened the possibility in the 1990s to add more pieces to the cosmological puzzle.

The teams used a particular kind of supernova, called type Ia supernova. It is an explosion of an old compact star that is as heavy as the Sun but as small as the Earth. A single such supernova can emit as much light as a whole galaxy. All in all, the two research teams found over 50 distant supernovae whose light was weaker than expected – this was a sign that the expansion of the Universe was accelerating. The potential pitfalls had been numerous, and the scientists found reassurance in the fact that both groups had reached the same astonishing conclusion.

For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up the Universe will end in ice.

The acceleration is thought to be driven by dark energy, but what that dark energy is remains an enigma – perhaps the greatest in physics today. What is known is that dark energy constitutes about three quarters of the Universe. Therefore the findings of the 2011 Nobel Laureates in Physics have helped to unveil a Universe that to a large extent is unknown to science. And everything is possible again.

I’m definitely among the skeptics when it comes to the standard interpretation of the supernova measurements, and more recent complementary data, in terms of dark energy. However this doesn’t diminish in any way my delight that these three scientists have been rewarded for their sterling observational efforts. The two groups involved in the Supernova Cosmology Project on the one hand, and the High Z Supernova Search, on the other, are both supreme examples of excellence in observational astronomy, taking on and overcoming what were previously thought to be insurmountable observational challenges. This award has been in the air for a few years now, and I’m delighted for all three scientists that their time has come at last. To my mind their discovery is all the more exciting because nobody really knows precisely what it is that they have discovered!

I know that Brian Schmidt is an occasional reader and commenter on this blog. I suspect he might be a little busy right now with the rest of the world’s media right to read this, let alone comment on here, but that won’t stop me congratulating him and the other winners on their achievement. I’m sure they’ll enjoy their visit to Stockholm!

Meanwhile the rest of us can bask in their reflected glory. There’s also been a huge amount of press interest in this announcement which has kept my phone ringing this morning. It’s only been five years since a Nobel Prize in physics went to cosmology, which says something for how exciting a field this is to work in!

UPDATE: There’s an interesting collection of quotes and reactions on the Guardian website, updated live.

UPDATE on the UPDATE: Yours truly gets a quote on the Nature News article about this!

(Guest Post) Letter from America

Posted in Science Politics, The Universe and Stuff with tags , , , , , , , , on January 10, 2010 by telescoper

Synchronicity can be a wonderful thing. Yesterday I mentioned the meeting of the Royal Astronomical Society that took place on January 10th 1930. The importance of this event was that it prompted Lemaître to write to Eddington pointing out that he had already (in 1927) worked out a solution of Einstein’s equations describing an expanding space-time; eventually this led to the widespread acceptance of the idea that Hubble‘s observational measurements of redshifts and distances of extragalactic nebulae were evidence that the Universe was expanding. 

Meanwhile, triggered by a recent article in Physics World, I have been having an entertaining electronic exchange with Bob Kirshner concerning a much more recent development about the expanding universe, namely that its expansion is accelerating. Since he’s one of the top experts on this, I thought “What better time  to have my first ever guest post?” and asked Bob if he would like to write something about that. He accepted the invitation, and here is his piece. 

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Twenty-first century astrophysicists (like Telescoper) are the wrong people to ask to cast your horoscope or maximize your feng-shui.  But even people who spend time in warm, well-lighted buildings staring at computer screens notice the changing seasons.  (This refers to conditions before the recent budget exercise.)  

For me, the pivot of the year comes right after the solstice, while the Christmas wrapping paper is still in the trash can.  Our house in Maine has a window facing south of east.  When the winter sun rises as far south as it ever does, a clear morning lets a blast of light come in one side, straight down the hallway and out the bathroom window. Househenge!  What does it mean? 

It means it is time for the American Astronomical Society’s big meeting.  This rotates its location from Washington DC, this year’s site, to other more-or-less tolerable climates.  Our tribe can mark the passage of the seasons and of the decades by this rhythm.  Never mind all that highfalutin’ stuff about the earth going around the Sun.  Remember that AAS in Austin? What year was that? 

In January of 1998, the cycle of the seasons and of available convention centers of suitable size put the AAS in Washington.  It was an exciting time for me, because we were hot on the trail of the accelerating universe.  We had some great new data from the Hubble Space Telescope (HST), a paper in the press, and Peter Garnavich, my postdoc, was going to give a talk and be part of a press briefing.  This was a big deal and we prepared carefully.  

Adam Riess, who had been my graduate student, was then a Miller Fellow at Berkeley doing the calibration and analysis on our data.  Adam’s notebooks were beginning to show troubling hints of cosmic acceleration.  I thought it would go away. Brian Schmidt, who had also been my student, was then in Australia,  calling the shots on this project.  He didn’t want to get out on a  limb over unpublished hints.  The idea of a cosmological constant was already making him sick to his stomach.  We agreed that in January of 1998, Peter got to say that the supernova data showed the universe was not decelerating very much and would expand forever.  That’s it.  Nothing about acceleration. 

Saul Perlmutter’s Supernova Cosmology Project also prepared a careful press release that reported a low density and predicted eternal cosmic expansion.  A report the next day in the New York Times was pretty tame, except for Ruth Daly speculating on the possibility of a low-density universe coming out of inflation models. Saul was quoted as saying, “I never underestimate the power of a theorist to come up with a new model.”  I have gathered up all the clippings I could find about who said what in Washington. (We used to call them “clippings”.) 

While a few reporters sniffed out the hints of cosmic acceleration in the raw data, in January 1998 nobody was claiming this was a solid result.  The paper from our team with the title Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant didn’t get submitted until March 13, 1998.  The comparable paper from the SCP was submitted September 8, 1998.  These are fine dates in the history of cosmology, but they are not in January.  It’s not for me to say when savants like the Telescoper were convinced we live in an accelerating universe, but I am pretty sure it wasn’t in January 1998.

In January 2009, the sun was once again shining right through our house.  It illuminated the American Physical Society newsletter kept in the upstairs bathroom. One of the features is This Month in Physics History.  If you want to find out about Bubble Chamber progress in January 1955, this is the place. Flipping through the January 2009 issue I was gobsmacked (American slang for “blown away”) to learn we were supposed to celebrate the anniversary of the discovery of cosmic acceleration.  Say what?  In January?  Because of the press releases that said the universe was not going to turn around? 

Being a dutiful type, a Fellow of the APS, and the oldest of the High-Z Team, I thought it was my job to help improve the accuracy of this journal. I wrote them a cheerful (on the third draft) letter explaining that this wasn’t precisely right, and, if they liked real publications as evidence for scientific progress, they might want to wait until March.  A volley of letters ensued, but not at internet speed.  The editor of APS News decided he had had enough education and closed the discussion in July.  The letters column moved on to less controversial matters concerning science and religion and nuclear reactors. 

The rising point of the sun came north, and then marched south again.    Just after the solstice, a beam of light flashed right though our   happy home. 2010!  Google alerts flashed the news.  More brouhahah about the discovery of cosmic acceleration.   Now in Physics World. I am depicted as a surly bull terrier in a crimson tenured chair, clinging desperately to self-aggrandizing notions that actual  publications in real journals are a way to see the order of events.  The philosopher, Robert P. Crease, who wrote this meditation, says he loves priority disputes.  He is making a serious point, that “Eureka!” is not exactly at one moment when you have an international collaboration, improving data sets, and the powerful tools of Bayesian inference at your command. 

But, even in the world of preprint servers, press releases, and blogs without restraint (I am talking about other blogs!), a higher standard of evidence is demanded for a real paper in a real journal.   A page in a notebook, an email, a group meeting, a comment after a colloquium or even an abstract in the AAS Bulletin (whipped up an hour before the deadline and months before the actual talk) is not quite what we mean by “having a result”.  I’m not saying that referees are always helpful, but they make the author anticipate a skeptical reader, so you really want to present a well-crafted  case.

If that’s not so, I would like to have my lifetime’s page charges refunded forthwith: that’s 250 papers x 10 pages/paper/ x $100/ApJ page = $250 000. Send the  check to my office.

So, Telescoper, how is your house aligned?  And why do the Brits put the drains on the outside when you live in such a cold climate?

The Word Game

Posted in Uncategorized with tags , , , on September 24, 2009 by telescoper

I don’t know why, but something just reminded me of a silly game I invented to make lectures more interesting. Probably it’s because the students have started coming back after the summer break. I started playing this game at one of the Erice schools run by Norma Sanchez, but it’s a long time since then and I can’t remember which one in particular it was. I never told Professor Sanchez this was going on in case she thought it was too flippant. I’ve always been scared of her since she loomed towards me and scribbled all over my transparencies at the end of one of my lectures because she disagreed with my use of the word “theory” (instead of model).

The thing about this and other schools of its ilk is that there are a bunch of invited experts giving short courses of lectures (maybe 4-6) to an audience of graduate students and young postdoctoral researchers. It’s quite intensive and I felt that it needed something to take away some of the strain.

The Word Game is played by one lecturer at a time. The other lecturers give the nominated individual a word which he/she must weave into his/her next lecture. There is no restriction on the word, and generally the more obscure it is the better. In the advanced version of the game the word is given to the lecturer immediately before the lecture (in a sealed envelope). However, for beginners I recommend giving the word at least a few hours beforehand to let them think a bit how to get the target word into their talk.

The audience have been told that the lecturer is going to include a target word and their job is to spot which word it is. If they succeed then the lecturer loses and has to pay a forfeit (perhaps a round of drinks for the successful spotters). If the students don’t get the right word then the lecturer wins and he gets a reward (probably also of alcoholic form). If the lecturer fails to include the word at all they to buy drinks for the lecturers as well as living out the rest of their days in shame. A league table is kept as the school goes on and the lecturer with the most successful word insertions at the end is declared the winner.

Choice of target word is tricky. If you make it too mundane then it is impossible to spot and if it’s too bizarre then it’s too easy. However, the former case can be avoided to some extent by insisting that the word occurs only once in the lecture. In the latter case the lecturer can use the device of introducing sundry other random complicated words to throw the audience off the scent of a tricky word. I generally award bonus marks if the word is embedded elegantly in the talk rather than hidden in a cloud of other words.

Not all lecturers want to play the game of course and some are more successful than others. I’d like to single out Brian Schmidt for his outstanding performance at one school, smoothly interpolating the word AUTOCLAVE into a lecture on Type Ia Supernovae in such a way that it went completely unnoticed by the students. On the other hand, I have also to mention that Rocky Kolb, misguidedly going for the advanced option during his first ever attempt at the game, completely failing to get the word AARDVARK into his lecture. In fact he insisted on being given the word in a sealed envelope after he arrived at the lecturer’s podium, starting his lecture with the words “May I have the envelope please?” That’s what you get for being cocky, Rocky.

I’ve always managed to get the words in myself, and did once successfully conceal ONOMATOPOEIA in a talk about galaxy formation. On the other hand, my attempt to get CANDELABRA into a talk about higher-order correlation functions was easily – and expensively – rumbled.