A Nobel Prize for Jim Peebles!
I’ve just dashed back in excitement to the office from two hours of mandatory Financial Report Training to write a quick post before my 12 o’clock lecture on Astrophysics & Cosmology because of the news about the award of the 2019 Nobel Prize for Physics.
My recent post was half right in the sense that half this year’s prize goes to Michel Mayor and Didier Queloz for the discovery of an extrasolar planet. I don’t know either of them personally, but heartiest congratulations to both!
My heart lept with joy, however, to see the other half of the prize go to Jim Peebles (above) for his work on theoretical cosmology. Much of the reason for that is that I’ve had the great honour and pleasure to meet Jim many times over the years. He is not only a truly great scientist but also a extremely nice man whose kindness and generosity is universally recognized. He’s not known as `Gentleman Jim’ for nothing!
The other reason for the excitement is that I was completely taken by surprise by the announcement. I had feared that his chance of winning a Nobel Prize had passed – I argued at the time that Jim should have been awarded a share of the 2006 Nobel Prize because without his amazing pioneering theoretical work the importance of the cosmic microwave background for cosmology and the large-scale structure of the Universe would not have been established so rapidly. As an author of the first paper to provide a theoretical interpretation of the signal detected by Penzias and Wilson, Jim was there right at the start of the modern era of cosmology and his subsequent work constructed the foundations of the theory of structure formation through gravitational instability. I was sad that he didn’t get a share in 2006 for this work, but am absolutely delighted that this has been rectified now!
This was one of the first cosmology books I ever bought. It’s an amazing piece of work that has been essential reading for cosmologists for almost 40 years!
Congratulations to Jim!
Now let me think about what to say to my students about this!
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In the Dark 
October 8, 2019 at 3:30 pm
Well deserved !
October 8, 2019 at 4:52 pm
I was delighted too. It’s easy to forget the pioneering work Jim did with Dicke in designing a radiometer to measure the CMB. The there was the prediction of dark energy long before the supernova results. Finally, he has always been hugely encouraging to those of us with an interest in the history of cosmology
October 8, 2019 at 5:33 pm
This is something I’ve always found confusing. Does including Lambda in the calculations — so that one has a more general case for studying cosmological evolution which includes Lambda = 0 — count as a prediction? Did Peebles merely do that or did he say “I am including it because I have solid reasons to believe Lambda ≠ 0, and here are those reasons”? (I think that people like Michael Turner wrote papers to that effect in the 1990s, but did people already have reasons to believe Lambda ≠ 0 in the 1970s?)
October 8, 2019 at 6:21 pm
Lambda went in and out of fashion several times. Jim told me that, as far as he was concerned, the Friedman models included Lambda as a free parameter so there was no reason not to include it in calculations.
October 8, 2019 at 6:52 pm
I remember Jim asking us to do galaxy number count models with k=0 and Omega_Lambda=0.7 in 1984. He was wondering if the steep blue galaxy counts were due to the bigger volume you get wit Lambda at higher redshifts. Red galaxy counts werent so steep so it was clear evolution was also playing a role in faint blue galaxy issue. But counts are still better fitted with Lambda than not.
October 8, 2019 at 7:05 pm
[…] Laureaten im Gesamtgefüge dieser Geschichte. Peebles wurde eher für sein Gesamtwerk als einer der Väter der heutigen Kosmologie geehrt als für einzelne Papers; in den letzten Jahren hat er vornehmlich Review-Papers über […]
October 8, 2019 at 7:09 pm
But Nobel prizes are weird. No doubt Big Jim deserves it – his calculations were always the ones you could trust whether for CMB perturbations or anything else. And the1980 LSSU book that Peter shows, was certainly a bible for me and anyone else working in correlation functions and early z-space distortions. But it also contains a lot of stuff on isothermal/isocurvature perturbations which was the original hierarchical model followed by most of the big names that now follow LCDM as a “second generation” hierarchical model. It was because CDM was what was rescued in 1980 from the wreckage of the isothermal model that made me tend to be suspicious of it. Strangely, Jim was one of the first to discuss CDM but he was also suspicious of it too. Anyway, cosmology has always been about paradigm shifts and Jim has caused more than his fair share, justly warranting the award of the Nobel prize.
October 13, 2019 at 7:18 pm
Jim might have been playing Devil’s Advocate when he talked about CDM or about Lambda. Is that what you mean? But baryon isothermal perturbations was his first love and he wasnt messing about there. In its day it was as big a bandwagon as LCDM.
October 14, 2019 at 3:21 pm
Philip – isothermal was the original name – no perturbation in the radiation and only perturbation in the matter. Only a slight shift to isocurvature with a small cancelling negative perturbation in the radiation. I recall someone telling me that there turned out to be almost as big a CMB signal from isocurvature as from baryonic adiabatic perturbations! But don’t think Jim was playing Devil’s advocate with either of these – after all he knew the move to CDM involved accepting Lambda and its apparently horrendous fine-tuning. He said at one of our conferences ” I don’t know a single particle physicist who wants to explain Omega_Lambda=0.7.”
Me – i never play Devil’s advocate with H0. My 1985 low-H0 model gave cosmology X-ray gas as the DM, Omega_b=1 consistency with nucleosynthesis and no need for the horrid cosmological constant while explaining the low CMB dT/T. Why the Good Lord bothered with the concordance model as evidenced by the WMAP/Planck CMB peaks i don’t know.
True – one can upset folks easily these days with smaller H0 controversies – see https://arxiv.org/pdf/1810.07628.pdf
and refs therein. But generally H0 too important to mess with.
I did see the H0 conference at Garching advertised and was pleased to see it wasn’t restricted to invited speakers only so I may attend!
Note there was also a consensus on isothermal baryon perturbations at one stage. And to be fair to Jim, it was brought down by GUT theory about baryon number non-conservation rather than an observation, at least initially.
October 9, 2019 at 12:43 pm
It’s a pity that he didn’t share the price earlier with Zel’dovich. I think this would be a well-deserved combination!
October 9, 2019 at 7:47 pm
I agree. But I recall seeing Jim and Zeldovich together at conference in Hungary in 1987 – not much love lost here! Sometimes when the geniuses get together things can get more serious! Jim, Alan Guth and inflation may be another example!
October 13, 2019 at 7:22 pm
It was certainly about the n=1 spectrum that Jim and Zeldovich crosses swords in Hungary conference. He said in his talk that he didnt understand why n=1 spectrum was called Zeldovich spectrum when Yu and Peebles talked about it earlier.
October 14, 2019 at 3:24 pm
Surprised Yu and Peebles was so late. Unsurprised Zeldovich & Novikov was so early. Maybe Jim was talking about submission dates or something?
December 11, 2019 at 11:13 am
[…] seems like yesterday when I heard the news that Jim Peebles had been awarded a Nobel Prize in Physics, but this week the man himself has been […]
August 12, 2022 at 11:21 am
[…] that there’s an interesting review article on the arXiv by elder statesman of cosmology Jim Peebles with the […]