Cosmic GDP drops 97% since peak star

Staunch Chicken Littles such as Alexander Ač love to talk about "peak oil", a hypothetical moment (and, in their opinion, a predictable and important moment) at which the global oil production reaches its global maximum.



But Phys.ORG has discussed an even more far-reaching peak of something, namely "peak star". The popular article is based on this paper:

A large H\(\alpha\) survey at \(z=2.23,\, 1.47,\, 0.84\, \&\, 0.40\): the \(11\,{\rm Gyr}\) evolution of star-forming galaxies from HiZELS (arXiv, published in Monthly Notices of the Royal Astronomical Society)

If we denote the number of produced stars per year as the "cosmic GDP", the years at which the cosmic GDP were maximized belongs to the distant memories. Since that time, the star production slowed down considerably. In fact, the "cosmic GDP" has decreased by a whopping 97% since that moment!




You would surely think that the Universe must be a horrible place to live if the "cosmic GDP" is just 3% of the value in those "good old times". Well, you would surely be wrong. Most of us didn't even know that the star production is so slow relatively to the maximum.

The peak was reached about 3 billion years after the Big Bang and I assure you, the world is a much better place today. During the "peak star", there wasn't even any Sun and the Earth – a planet that biased environmentalists consider more important than billions of other planets in the Universe ;-) – didn't exist, either.

I find it rather likely that 3 billion years after the Big Bang, our visible Universe contained no intelligent life but I am sure that many folks who think that "intelligent life is an inevitable omnipresent trash that immediately erupts almost everywhere" will disagree. We don't really know the answer.

It's also being estimated that despite the infinite length of the future life of our Universe that will increasingly approach the empty de Sitter space (its form of energy, the cosmological constant, already makes up over 70% of the energy density in the Universe, so we're already "pretty close" to the empty de Sitter Universe of the asymptotic future), the total number of stars in the cosmic history book will only increase by 5% since this moment. (Well, more precisely, we are talking about the total mass of the stars rather than the number.)

So if you measure the total "amount of fun in the life" as the integral of the product of the number of stars and (i.e. over) time, \(\int \dd t\,N_{\rm stars}\), then about 95% of the fun in the Universe has already taken place and almost nothing is awaiting us! We could also commit collective suicide and we could at most lose 5% of the fun events in our history.

The only problem with this pessimistic, nihilist conclusion is that we know very well that the "total amount of fun happening annually in the Universe" is proportional neither to the number of stars nor to their total mass. As I have mentioned, most of us believe that the life in the Universe is much more fun today than it was during the "peak star" 11 billion years ago.

The star production was needed for our Solar System to be born but many other events were needed for us to be here and to have some fun, too. The latter events depend on the existence of the stars and they're inevitably delayed by a certain period of time. And the things that decide about the GDP or the fun in life today – when the existence of the Solar System may be taken for granted – may proceed at a much faster rate so that those 7.5 billion years of the Sun's remaining life may be enough for a lot of fun – fun that is "almost" infinitely larger than what we have already seen (think about the speculations about the "technological singularity" which may be inaccurate but they're right about the point that the progress or GDP may continue to grow).

This objection is uncontroversial and kind of amusing in the case of "peak star". However, my point is clearly more far-reaching ideologically. My point is that the "amount of fun happening on the Earth every year" is clearly not proportional to the crude oil production, either. It isn't proportional to the electricity that is consumed, it isn't proportional to the number of SUVs or solar panels or soybeans that are sold, it is proportional to nothing particular that may be associated with the life in a given era.

The fun in the life is a totally independent quantity which depends on many things and the relationship of the fun in the life to other quantities is indirect, indeterministic, and it is constantly changing. Moreover, the relevant quantities today, such as the economists' GDP, are changing (and mostly increasing) by several percent per year while the 97% drop in 11 billion years corresponds to a modest 0.00000003% decrease per year which is negligible.

We have mentioned some of the reasons why "peak oil", much like "peak star" – even if we could determine or predict when it exactly occurs, which we can't – has no implications for the things we really care about in the world.

And that's the memo.

Steven Weinberg defends linear collider, science

Last week, Steven Weinberg gave a talk in Arlington, Texas. This is the questions-and-answers part of the talk:



It's 28 minutes. At the end of the regular talk, he mentioned various indirect advantages from building a new linear collider etc. He makes a good joke when they prepare an award for his memorable talk: How did you know in advance that my talk would be memorable? I would be inclined to make exactly the same comment.




A person asked about new physics. Weinberg focused on the identity and detection of the dark matter particle. The same person and another one wanted to ask about string theory – that's what people are really excited about. Weinberg said it's extraordinarily mathematically powerful and it hasn't been possible to compare its characteristic predictions with experiments.

He says that the International Space Station was allowed to go at the same time when the Superconducting Supercollider was cancelled – even though it was 10 times more expensive and has produced no science. He strengthens the claim by saying that the astronauts have never produced any science. Of course, some people in the audience are stunned, others applaud. ;-)

The linear collider would measure the properties of the Higgs and all the things much more accurately. I have some doubts whether this information is worth $10 billion dollars, especially because it is somewhat likely (40%?) that they would exactly agree with the Standard Model, within the ILC precision. And if there were a disagreement, it would still fail to clarify where the disagreement comes from, what are actually the new particles and physical phenomena that are responsible for the deviation. Imagine that the ILC finds out that the diphoton decays of the Higgs boson are indeed 70% more frequent than the Standard Model says. Would we be fully excited and satisfied? Nope. It would only be a justification to build a collider that may actually find the new beasts that are responsible. So why wouldn't we build this collider immediately?

For those reasons, I would tend to think it's better to save a little bit more money and build a new SSC-like collider that exceeds the LHC by its superior brute force, by the energy.

Weinberg said that he was attracted to theoretical physics by reading popular books when he was at the high school. He also mentions that for a long time, he believed he had to know everything before he starts to do research, so he was reading lots of books. Then he learned better. Well, I still think that his previous "mistake" was very valuable because it gave us Weinberg who really did and does know everything about the particle physics and cosmology of his era.

Most of the time, nothing comes out of the research so it may be frustrating. Sometimes, something comes out. If you love it, do it, if you don't, then don't do it...

Weinberg's Arlington talk was a part of a broader linear collider conference (its web).

Galileo's 1633 trial: a tragic hero

I was pleased that virtually all the media criticize the recent manslaughter verdict against the Italian seismologists.



Many outlets compare the trial to the 1633 trial against Galileo Galilei. So I decided to find a video explaining some details about that event in particular and Galileo's life in general – and the 52-minute Chicago talk by Rocky Kolb (whom I hosted once at Harvard) from 2011 turned out to be a very informative choice although I clearly disagree with many sentiments that Kolb expressed during the talk.




Some people say that Galileo has overreached, he was arrogant because throughout his life, he enjoyed to point out why idiots around him were idiots, and all this stuff.

Galileo wasn't arrogant when he explained that the difference between him and the stupid folks around him was greater than the difference between humans and animals. He wasn't arrogant because his statement was clearly true and very important. It was very important from the viewpoint of the abstract truth; it was very important for the civilized character of the present, too.



Off-topic: Decay: Something truly unexpected has been discovered at the LHC! By young Oxford employees at CERN.

At the beginning of the talk, Rocky Kolb tells us various things about Galileo's ability to get the maximum out of the telescope (that he "devised" but didn't invent – but he deliberately used the ambiguous verb "devised") and he describes other events from Galileo's CV.

Kolb says that astronomy had been a part of the mathematics (and not physics) departments because astronomers were only supposed to find "kinematic fits" for the observed trajectories but they were not trying to find the "physical or dynamical causes". And he reminds us that the Catholic Church hadn't had an official position on Copernicanism: they would say it's just some models that didn't say anything direct about the reality (they were agnostic in the disagreement between Ptolemy and Copernicus). Galileo's own effort to codify his understanding of the astronomy (he only became a Copernicanist at some point when he studied this problem at depth) is what forced the Church to adopt an official position (unfortunately, one chosen by theologians and incompetent astronomers according to a literal interpretation of the Bible) and to bring him into trouble and impose a sort of a ban of Copernicanism for him.

I am extremely grateful to Galileo for having done what he has done and he was just right about these scientific and political issues. Let me mention some of the aspects discussed by Kolb.

For example, Galileo was being implicitly criticized for claiming to be able to correctly interpret the astronomical statements in the Bible. Was he overreaching? I don't think so. Because Christianity was such a universal and omnipotent part of the culture of that epoch, it was virtually impossible to convince anyone of anything if you outright denied the tenets of Christianity such as "the validity of the Holy Scripture (at least in some sense)".

Another fact, and it is a related fact, was that the Church bureaucrats had a monopoly to "interpret the reality". Everyone else was doing just some "details" that were not allowed to influence any "greater questions". But Galileo Galilei clearly had the insights that were going to substantially change some "greater questions": he was giving birth to the scientific method as we know it and it is no detail.

Because of this reason, it seems totally obvious that he simply had to struggle to overtake the competency to determine what is true about the deepest cosmic questions from the Church bureaucrats. After all, as Kolb admits, Copernicus himself wrote just a cryptic text filled with complicated mathematical expressions and jargon that didn't even attempt to reach a broader readership, so his work became a hobby for a small group of astronomers only. Thank God, Galileo didn't want to be satisfied with a similar outcome. If he were satisfied, the Western civilization could be as unscientific and unenlightened in 2012 AD as the Islamic anticivilization is. The religious leaders could dictate what to think about the motion of celestial bodies – and all other fundamental enough questions – even today.

So the statement "I am able to properly interpret the biblical astronomy" was simply saying "I know how the things actually work" translated to the Latin of the time in which the "power to define the truth" and the "power of Church bureaucrats to preach" were considered synonymous. The Bible was considered true by definition, so of course that given this assumption, the ability to explain how the Solar System actually worked was the same thing as explaining how it worked according to the Bible.

For the very same reason, Galileo – who wanted to become a monk but (because of the pressure from his father) tried to become a physician for a while – ultimately grabbed the credentials as a mathematician as well as a philosopher. He realized that the "philosophers" of his time were just doing rubbish – and they were mostly parroting and uncritically celebrating folks like Aristotle which meant that there was almost no potential for genuine progress. At the same time, these deluded people had lots of influence so Galileo realized that he needed to be considered a philosopher as well in order to gain the capacity to correct many of the unscientific misconceptions that were spread by the "philosophers".

Much of this stuff that Galileo was doing was politics but Galileo was the good guy who actually possessed the truth.

In 1632, Galileo wrote The Dialogue Concerning the Two Chief World Systems. It is a fictitious discussion between Salviati, a hero named after Galileo's friend and presenting many of Galileo's positions, and Simplicio, a guy described as an idiot who presents the opinion of some stupid people of the time such as Ludovico delle Colombe (1565-1616?), Galileo's fiercest detractor, and Cesare Cremonini (1550–1631), a colleague who rejected all the observations based on telescopes as a matter of principle. And of course another stupid guy, the Pope (Urban VIII, reign 1623-1644). The discussion is moderated by a smart laymen called Sagredo who is neutral at the beginning.

Kolb says that "he had no idea" why Galileo would write a text in which an idiot looked like he was the Pope. Well, I have some idea. It's because this was exactly what was happening in the real world, too. The Pope was one of the idiots of Galileo's time and it was totally necessary for any progress to challenge this particular idiot, too. Again, I think that if Galileo hadn't had the courage to challenge the Pope, the Western civilization wouldn't really change and the scientific revolution couldn't begin because obsolete dogmas and their champions would continue to have the power to stifle any important scientific development.

Galileo's "Dialogue" quickly made it to the bestseller lists. At some moment, the book was banned. Of course, the book became even more popular because of that. Soon afterwards, the Pope complained to the Inquisition. In 1633, Galileo arrived for the trial to Rome (his clever attempt to relocate the trial to friendly Florence was denied). See a 5-minute cartoon version of the trial. Galileo faced a possibility of Giordano Bruno's fate – whose tongue was (after an 8-year-long trial) glued to the mouth so that the politically correct assholes of his time didn't have to worry that he would say something "dangerous" before he is burned at stake.

All the materials from the trial became publicly accessible – despite the obvious Catholic Church's efforts to keep them secret – thanks to Napoleon Bonaparte. He visited Rome and kindly asked them, with a minor help of this army, to hand out the materials so that they may be kept in Paris. ;-) In 1845, the French agreed to return all the materials to the Vatican but there was a condition: everything must be published.

But back to 1633. The Pope was the clear driver of attempts to harass Galileo. So the court was filled with Galileo's enemies. But what could have they accused him from? The book actually had signatures of several Catholic officials who authorized the book as OK for all audiences. So how could they punish him if they had allowed him to write it?

The trial was pretty short: about five pages. Four depositions. First one: Do you know why you're here, Dr Galileo? It's probably about my book. Do you recognize it etc.? Were you in Rome in 1616? Yes, I came to learn about the geocentrism vs heliocentrism debate. The Church had banned him from promoting heliocentrism, at least the possibly fake official documents suggest so. Galileo argued he didn't really remember what he wasn't allowed to do – defend, teach, study, promote, whatever. Galileo argued that he didn't even defend heliocentrism; instead, he was promoting both sides of the debate, including the imbeciles, mental pygmies, dumb idiots, people hardly deserving to be called human beings, people too stupid to recognize their own limitations (these are Galileo's actual words but yes, great minds think alike), in a fair and balanced way. But the Church said he wasn't allowed to teach it in any way.

To defend himself, Galileo said an incredible lie: he said that the book defended the geocentrists (called the "imbeciles" etc.). An attorney would probably stop him from making such an implausible claim but he was defending himself.

Next time, Galileo said that he suddenly understood why they were thinking he was defending Copernicanism. He actually was so smart and nice that he described the Copernican interpretation – so obviously wrong – in a way that actually looks much more plausible than it is. :-) He offered them to fix the things in another edition of the book.

Galileo got 8 days to prepare a defense. He said he didn't remember any ban on "teaching" heliocentrism. And he said he believed that he didn't have to inform the censors about the injunction. My only error was the ambition to appear smarter than everyone else, he said. And Galileo complained about his health, old age, and good name.

The Inquisition asked him a simple question: Had he ever been a Copernican? Galileo said he was uncertain until 1616 but since the official position was taken, he believed Ptolemy. Clearly a lie. He denied being Copernican. The Church said they didn't believe him.

On June 22nd, 1633, Galileo had to listen to the sentence in humiliating clothes. He's suspect of the heliocentric heresy, he was told. Galileo saved his life by a verbal self-destruction. There is no way how he could have said "it is moving, anyway" during this scene. The life in prison was signed by 7 of the 10 cardinals only. It's not clear to me whether the remaining 3 wanted a tougher or milder punishment, however. The Pope – who orchestrated the trial behind the scenes – later changed the verdict to a "life-long house arrest" in order to look magnanimous.

Galileo died in 1642. His remains were soon moved to a more prestigious place but as recently as in the 19th century, his "Dialogue" could imperil your immortal soul even if you just read it.

Kolb asks whether Galileo was a classical tragic hero. My answer is Yes, he was. But he was much more than that, too. He was a man who opened the doors to scholars' ability to challenge the opinions held by the entire hierarchy of Church bureaucrats (the Christian churches became able to reform themselves and compatible with the modern world as a result of that), who established the scientific method, and who was still able to save his life by a sequence of tricks and lies. His achievements included the highly technical and experimental ones, conceptual and theoretical ones, as well as political ones, and all these three groups were very important.

Alan Guth on himself, science, cosmology

Aside from Edward Witten, another well-known winner of the Newton Medal (in 2009) was Alan Guth, the first father of cosmic inflation. Two month ago, the Institute for Physics posted the post-Newton-Medal interview with him, too.



He had no science background in his family. At least he doesn't remember any background. But his family was happy when it learned that Alan was into science. Well, they were happy for a while, before they realize that science wasn't quite the same thing as engineering, but it was fortunately too late for them intervene. ;-)

He grew up in a small town, Highland Park, New Jersey which only has 15,000 inhabitants or so today. Well, it may be a small town but your humble correspondent knows it very well from his Rutgers years (1997-2001). In fact, I officially had a physician over there although I have never visited him so at least, I was sometimes going to do shopping in a grocery store over there. You may guess what Guth's father was: Yes, he had a grocery store in Highland Park. It burned at some point. ;-)




Many or most people in the Academia and especially theoretical physics come from scholarly families – the tradition usually goes back several generations, in fact. It has advantages and it has disadvantages. This "inherited occupation" adds some amount of sterility to the environment. On the other hand, the "scholars who inherited the job" are trained to be productive scholars so I am pretty sure that in average, they write many more papers than the "first explorers of the scientific occupation in a family". The latter may often be more audacrious and creative, however.

Guth was affected by a fabulous high school teacher. He didn't know too much physics, Alan Guth later realized, but he was still lucky to have a dynamic guy of this type. He described some success of him as a theoretical physics when he was a high school pupil – something based on a pure thought but it still works well. ;-) Alan Guth married his high school sweetheart. Two kids, the son is a mathematician who proved e.g. the Son-of-Guth Theorem (naming convention due to Susskind, if I caught it well).

MIT was where he went to college. MIT was unusual socially because it didn't separate people who are "in" and "out". He liked it. He was surprised he had superior competitors – unthinkable at the high school. People specialized a bit. He became sure he wanted to be a theoretical physicist. Grad school. Postdoc jobs. One of them made him interested in cosmology. Magnetic monopoles in the early Universe became his important obsession.

Alan Guth explains what cosmology is – science of the Universe as a whole, especially focusing on its childhood. The Big Bang Theory was great but it needed things to be fine-tuned and failed to explain the uniformity, too. He discovered cosmic inflation while solving another problem, namely why Sheldon Cooper of The Big Bang Theory has't found magnetic monopoles during their polar expedition. Guth explains why inflation gives the bang to the Big Bang. A gram of matter is enough to create our large visible Universe. A gram is not much but it's still much more than the Planck mass so it's not a theory of everything.

It looked dramatic so he was afraid it was wrong but after some talks, especially those with big shots in the audience, it became clear it wasn't wrong. Today, cosmology is in the golden age, indeed. Things are accurate. He describes the composition of the Universe and the absolute nothingness at the beginning. God is pointless because because He is just a redundant connecting link – with this addition, you must just explain why He is there instead of the Universe. ;-)

Hat tip: Joseph S.