The Humble Origins of the Big Bang Theory

PART 2

Andrew McDiarmid: Welcome to ID the Future. I’m your host, Andrew McDiarmid. Today I conclude my conversation with Jean-Pierre Luminet about his new book, The Big Bang Revolutionaries, The Untold Story of Three Scientists who Reenchanted Cosmology, published by Discovery Institute Press.

The discovery that the universe had a beginning is one of the most remarkable achievements of 20th century science. It sparked a cosmological paradigm shift and offered a radical new way to understand our world. But alas, the three scientists most responsible for the Big Bang revolution are largely unknown to the general public and underestimated by astrophysicists and cosmologists. While The Big Bang revolutionaries amends the record by telling the remarkable story of how three men, Belgian theoretical physicist, Georges Lemaitre, Russian physicist Alexander Friedmann, and the Russian American physicist and cosmologist George Gamow or Gamoff, in the face of conventional scientific wisdom, offered a compelling new view of a singular creation of the universe in what Lemaitre termed a primeval atom.

Dr. Luminet, who is joining me today, is a French astrophysicist specializing in black holes and cosmology. He is emeritus research director at the French National Center for Scientific Research. He is a member of the Astrophysics Laboratory of Marseille and the Universe and Theories Laboratory in Paris. Luminet has been awarded several prizes, including the Georges Lemaitre Prize for his work in cosmology, the UNESCO Kalinga Prize and the Einstein Medal for Popularization of Science. He has published more than 20 science books, eight historical novels and eight poetry collections. And get this, the asteroid 5523 Luminet was named in his honor. Jean-Pierre, welcome back to ID the Future.

Jean-Pierre Luminet: Yes, thank you for this second invitation to develop a little bit about this fascinating history of modern cosmology.

Andrew McDiarmid: Yes, thank you for your time. In the first half of the conversation that we’ve had, we talked about the importance of knowing the history of science. You talked about discovering it yourself and then being able to share with others the history of science through your non-fiction and your fiction books. You began to give us more detail about the true fathers of the Big Bang Theory, Lemaitre, Friedmann and Gamow. We also talked about whether the Big Bang Theory was friendly to the doctrine of creation ex nihilo. And we did get a chance to zoom into Lemaitre’s faith and how that informed his work, which I thought was very interesting. Today, we’ll continue to discuss the true heroes of the Big Bang Revolution and how the Big Bang Theory has fared in light of the latest scientific evidence.

Let me jump in there. In explaining the sad neglect of Lemaitre in the standard history of the Big Bang theories’ triumph, one cause that you point to was Lemaitre’s humility. He seemed much more interested in pursuing the truth than in who got credit for it. And in fact, just a few weeks before he died, and I read this in your book, when informed by his assistant of the fossil radiation discovered by Arno Penzias and Robert Wilson, he has said to have commented, “I am glad now we have the proof.” But for many years he did not have the proof and he had to rely on his intuition. Tell us about Lemaitre’s humility and his patience.

Jean-Pierre Luminet: Yes, yes. In fact, before Lemaitre humility, one of the reason, as I also explained in my book of the initial neglect of Lemaitre thinking was just because his first fundamental paper published in 1927 about the interpretation of galaxy redshift with the expanding space was written in French. So it’s a long story, and it’s only after English translation, in 1931, that Lemaitre became internationally known. But you are right, Lemaitre’s humility, in fact, you know that it’s a French astronomer called Paul Couderc, probably American people have never heard about Paul Couderc, was probably the first to rightly underline the priority of Lemaitre over Hubble, concerning in fact, the discovery of the expanding universe. And the so-called Hubble’s Law until it was only recognized in 1950, the book of Paul Couderc. But what’s interesting is that Lemaitre himself never claimed any priority about that. And in fact, Lemaitre even found that the Couderc praised overly complimentary for him.

And this was of course one of the sign of his deep humility. Another sign has been told to me by the assistant of George Lemaitre, named Odon Godart that I met in Louvain University, 30 years ago, before himself died, unfortunately. And Godart told me that story that when the news of the discovery of fossil radiation by Penzias and Wilson was announced in 1965, Lemaitre was very ill, in hospital in Louvain with heart problems. Godart told me that, “Yes. So he was very,” and Godart told him, told Lemaitre about the discovery, and Lemaitre replied that he was happy because we now had the proof of his theory, but a little bit disappointed because the fossil radiation was not made of cosmic ray as he initially expected, but in the form of electromagnetic radiation. But in fact, contrary to George Gamow, who after the discovery of Penzias and Wilson, claimed that he had priority, and he claimed for Nobel Prize.

In fact, Lemaitre never claimed to have priority on any major advances, is modern cosmology. Although he was really the father of most major advances. Advances which should have won him the Nobel Prize in physics, that of course he never got. So this is a real humility of Lemaitre and consistent with his personality, very attaching personality of both a religious man, but with very deep thinking and everything.

Andrew McDiarmid: And that intellectual humility is very important to scientists. It needs to be part of the scientific enterprise. We do have to be humble. We do have to be patient. And we shouldn’t be too selfish about this enterprise because we’re all standing on the shoulders of giants. We’re all building on what has come before. So I think Lemaitre demonstrates this.

Jean-Pierre Luminet: It’s a rather rare attitude. In fact, among the scientists, if we take the example of Hubble, it’s exactly the contrary. Hubble constantly claimed that everything came from his research to get more credit for Mount Wilson Observatory. And [inaudible 00:44:07]. Even also today, some of the great [inaudible 00:44:09] scientists of the day try to claim that everything come from them. So it’s quite remarkable that personality like Lemaitre, who was real father of the Big Bang, never claimed any priority about that.

Andrew McDiarmid: It is indeed. What about Alexander Friedmann? Was he as cautious as Lemaitre about using science to support a Judeo-Christian worldview?

Jean-Pierre Luminet: In fact, we have some information about Alexander Friedmann’s religious beliefs. In fact, we know that he was an Orthodox Christian. For instance, in 1925, in fact, just before his accidental death, when he was still the director of the main geophysical observatory in St. Petersburg, at the time of anti-religious and anti-church persecution by the communist regime, Friedmann married his second wife according to the Orthodox Christian rule. So in fact, the term of creation of the world out of nothing that he used for the first time in 1924 in his book, The Universe as Space and Time, was not in fact a matter of empty words for him. It mean really something deep. However, it’s funny that in fact, no doubt that [inaudible 00:45:47] towards the communist authorities, Friedmann did not make the connection with the biblical account, but did the connection with the Hindu doctrine of the cyclical creation of the world with the God Brahma. So in some sense, in some way, Friedmann was a little bit, was more concordist than Georges Lemaitre, but with a strange way invoking rather Hindu religion rather than Catholic or Christian religion.

Andrew McDiarmid: Okay. And you mentioned that Friedmann never, was he able to leave the Soviet Union or was he stuck there? Could not visit America or other parts of Europe?

Jean-Pierre Luminet: No, Friedmann could not leave Russia, the Soviet Union. But I’ll tell the interesting story of the fact that when Friedmann published in his first fundamental article of 1922, about the first dynamical solution of Einstein’s equation, Einstein in the first moment reacted negatively to this article of Friedmann. Friedmann could not leave the Soviet Union, but he talked to one of his friend Krutkov, who had the right to leave Soviet Union to meet Einstein in Berlin and discuss with him. And in fact, Krutkov was who convinced Einstein that it was Friedmann who was right and not Einstein.

Andrew McDiarmid: Interesting. There’s a lot of barriers here. There’s a language barrier. There’s the distance barrier between these great thinkers, and it’s amazing that we still got the revolution out of it. By all accounts, George Gamow seemed to have a personality that fitted him well for bucking the system and thinking outside the box. Tell us a bit more about Gamow’s personality.

Jean-Pierre Luminet: Gamow was a Soviet and American polymath. He was born in Russia, but after a naturalized American. So he was really a polymath. He was also a theoretical physicist. He was a cosmologist. Later on, he was interested in ADN in biology and something like that. And in the field of cosmology, he was an early advocate and developer of Lemaitre Big Bang Theory. But he had it with nuclear physics. He had it to the Big Bang Theory, the nuclear physics, and the fundamental idea of what we call the Big Bang nucleosynthesis, namely the generation of light elements in the hot Big Bang universe.

However, it’s interesting to see that Gamow’s scientific reputation was a little bit altered by his high sense of humor and fantasy. Gamow delighted in practical jokes and humorous twists, including in very serious scientific publications. So there is the famous story of… His most famous prank was a pioneering article called the Alpher-Bethe-Gamow paper of 1948, in which they described the genesis nucleosynthesis of light elements. So it was a very serious paper in its style and contents, but Gamow, in fact, could not resist adding his colleague Hans Bethe, to the list of authors, as a pun, to the first three letters of the Greek alphabet, alpha, beta, gamma. Alpha, beta. Bethe, Gamow. As Bethe never participated to the writing of the article.

The first moment Bethe reacted negatively to this utilization of his name because he was not asked for that. But after seeing the success of the article, he said, “Okay, it was okay.” Also, I can add that in his late career, Gamow directed much of his attention to teaching and wrote popular books on science, including the famous Mr. Tompkins series of books, very [inaudible 00:50:52] books for popularizing general relativity and all that. And some of them remain in print more than half a century after the original publication. But anyway, Gamow get a Nobel Prize in physics as he claimed after the discovery of cosmic microwave background radiation. Maybe it was too late for him, but because his sense of humor and fantasy could refrain a little bit the idea of giving him a Nobel Prize in physics.

Andrew McDiarmid: He sure sounds like a character. What specifically did he do to help further the Big Bang Theory and Lemaitre’s ideas? I just want to be clear on that.

Jean-Pierre Luminet: As I said before, in fact, one of the reason was the lack of convincing and definite experimental proofs, in fact, until the discovery of fossil radiation. But in fact, at a more theoretical level, I’d say that also that was the wrong idea, that the Big Bang necessary implied an initial point-like singularity, namely an absolute beginning of time where all physical quantities become infinite, which is of course, physically absurd. In fact it’s not that, it’s just the history of evolution of universe starting not from a point-like singularity, but starting from a very hot and dense state. Maybe described also, not only by general relativity, but also by quantum physics. I know we try to develop new theory mixing general relativity and quantum physics to describe the very, very, very early universe. They are called quantum gravity theories.

Another and maybe also interesting reason and maybe more interesting reason for the reluctance and to accept the [inaudible 00:53:13] is in fact of philosophical nature because for minds like Einstein, Eddington and later on Fred Hoyle, in fact, it was the British astrophysicist, Fred Hoyle, who proposed the term Big Bang by derision, to mock the idea. And he proposed instead the alternative steady state theory. Because for him, and for them, it was difficult to admit that the universe was changing with time.

So it’s just philosophical prejudice that universe must be eternal, does not change with time. And this is really why the Big Bang Theory was a scientific revolution. The idea that the universe is not eternal. It has a history. A part of the history begins at time, finite time in the past. Perhaps universe existed before, in new theory of contouring gravity, we have some idea of pre Big Bang universe, what was not the case at the time of Friedmann and Lemaitre, but so was really a revolutionary idea, which was not accepted by most of the scientific community, that the universe was finite in time. That’s beginning in the past, and he was evolving.

Andrew McDiarmid: And you do explain in your book, the stages of this relativistic science revolution. And I thought that was very interesting. It takes time for these ideas to percolate, to be accepted, to be built on and added to, and you allude to that in your book. So it did take several decades for the basic ideas of the Big Bang Theory to be accepted for the reasons that you have mentioned. What about today? Is the Big Bang Theory today now confirmed by astronomical observations?

Jean-Pierre Luminet: Yes. In fact, until the 1970s, the three observational pillars of the Big Bang models were based on one, on the interpretation of galaxy redshifts in terms of expansion space made by Lemaitre. After by the origin of light atoms like hydrogen, deuterium and helium in a very hot phase of the early universe made by Gamow and his collaborators. And finally, the discovery of fossil radiation, which was a cooled electromagnetic remnant of this hot phase in 1965.

Since then, immense progress has been made thanks to major telescopes such as WMAP, Planck, who observed in very, very details, structure of the cosmic microwave background radiation, and also more traditional telescopes such as the famous Hubble Space Telescope, and more recently the James Webb Space Telescope, which allowed the astronomer to go more deeply in the past of the early universe. And we can now say really that we have entered an era of high precision experimental cosmology, which was not at all the case at the time of Friedman, Lemaitre and even Gamow. And this high precision experimental cosmology enables us to fix the fundamental parameters of the universe to within a few percent, only a few percent. So really detailed prediction. Despite all this, a number of questions remain unanswered today. Notably the exact nature of the dark matter and dark energy that we know governs the cosmic evolution. So it’s not the ordinary matter with galaxies and stars, which govern the cosmic evolution. Two strange ingredients, much more important, dark matter and dark energy.

Also, there is the… And I have a special chapter on this in the book, the topological question that I’ve been working on a great deal concerning, in fact, it concerned the global shape of the space. Is it infinite or is it finite with no limits, with no edge, with a particular shape? I described that in one of my book translated in English, which called The Wraparound Universe. And there is also the question of whether the Big Bang was really a singularity or whether thanks to quantum effects that are still poorly understood, Big Bang could have been preceded by a pre-Big Bang phase.

So this is a work in progress with some quantum gravity theory, which extends a general picture of Big Bang Theory to a possible pre-Big Bang phase, adding some quantum effect. While for me, it’s a more interesting part of fundamental physics today to try to enlarge the general picture of the Big Bang model with us changing the fundamental claims from [inaudible 00:59:15] but eliminating some problems of the Big Bang Theory itself, like for instance, the singularity.

Andrew McDiarmid: It’s an exciting time to be studying this and researching this. Now, a final question. The Big Bang Theory has been in the news lately. What do you make of the recent claims that the image of mature early galaxies captured by the James Webb Telescope are undermining or changing the Big Bang Theory?

Jean-Pierre Luminet: I will say that just for me to make buzz. In fact, scientific information, including that coming from very serious space agencies like NASA, European Space Agency, has become partly spoiled in fact, by exaggerated claims, just to sell better the business of scientific research and get more credits, for instance, and more recognition of researchers. In fact, for the general audience, it’s more selling for popular science magazine or website of scientific information to say that new observations call into question standard model cosmology, rather than to say it’s the same. For instance, for also discovery of black holes, [inaudible 01:00:43] cosmology. So it’s more appealing rather than to say that in fact, the detailed standard model just need to be studied in greater depth. And this is exactly what is happening now with the recent discoveries by the James Webb Space Telescope, fascinating discovery, but of galaxy that form a little bit faster after the Big Bang than previously thought.

But I can say that, believe me or not, this does not in any, recall into question the broad outlines of the Big Bang model, but it does invite researchers. And in fact, this is what is most interesting in this affair, to better refine the parameters required for galaxy formation. For example, the idea of a first generation of primordial black holes, which is wonderful. Black holes, we mentioned, it’s one of my specialties. So the idea of a first generation of primordial black holes created just after the Big Bang that would have acted as seeds accelerating the formation of the galaxy could be taken up again to explain this observation. And this idea was put forward some 30 years ago. And I mentioned, for instance, this idea in my popular book on black holes that I published by Cambridge University Press as soon 1992. So, as I said, of course, the observation of the James Webb Space Telescope are fascinating. But as far as I know, they does not at all undermine the general Big Bang.

Andrew McDiarmid: Yeah. Doesn’t change the basics.

Jean-Pierre Luminet: [inaudible 01:02:43] To look into more deeply into the details of the standard model.

Andrew McDiarmid: I think it’s very interesting to have the instruments that we have today, like the James Webb Telescope and the other machinery that you’ve mentioned, because you mentioned in your book that telescopes don’t just go the distance as far as space, but they also help us go back in time. They help us see the past, and that’s exciting. But it’s great to hear that these ideas are holding up, and the Big Bang revolution is still very much in play. And it’s good to have that intellectual humility and patience that Lemaitre demonstrated as we move further into the exploration of this. And on that note, I want to thank you for all of what you’ve brought to the subject. You have an amazing mind and amazing skill to demonstrate this to the public. So I want to thank you for all that you’ve done in service of cosmology and this grand exploration of our universe.

Jean-Pierre Luminet: Thank you, Andrew. It was a great honor and pleasure to have the opportunity to discuss about what made most of my life as a researcher with this fascinating mystery of the universe.

Andrew McDiarmid: Well, readers and viewers, it’s time to get your copy of The Big Bang Revolutionaries. You can do that at discovery.press. It’s of course available everywhere the books are sold. But discovery.press will take you straight to it. You can read more, and you can tap into some excerpts that we have in written form, as well as a reading that I’ve done for ID the Future. So lots of resources, and just get your own copy and read this fascinating story of the history of this amazing cosmological revolution that has changed our view of the universe. Discovery.press is the website to get the book.

Thank you again Dr. Luminet. For ID the Future, I’m Andrew McDiarmid. Thanks for listening and watching.