Doctor Atomic

The story of the first atomic bomb test on July 16, 1945, is not necessarily a subject for an opera. And yet composer John Adams and librettist Peter Sellars dared to write and stage one about a scientific drama.

In fact, the opera has no dramatic plot; instead, it features many dialogues about scruples, ambition, fears about life, doubts, and the search for redemption. Doctor Atomic is the father of the atomic bomb, Robert J. Oppenheimer, who was not only a brilliant scientist but also well-educated in literature and philosophy.

Typical Oppenheimer with his hat and pipe (©SWF)

Robert earned his doctorate in theoretical physics at the age of 23 in Göttingen in 1923 under Max Born, who was full of praise for his student, who, in turn, recalls his time in Göttingen, “The work here is dizzying. You live in a state of constant mental excitement.” Indeed, “In those years, physics was not developed—it erupted, Born remembered.”

The opera begins in the style of a Greek tragedy with a choir dressed in black, which, however, does not sing darkly about fate, but informs the audience about some trivialities of physics.

We believed that
"Matter can be neither
created nor destroyed
but only altered in form.“

We believed that
”Energy can be neither
created nor destroyed
but only altered in form."

But now we know that
energy may become matter,
and now we know that
matter may become energy
and thus be altered in form.

Oppenheimer leans against a wooden frame
representing the temporary shanty town of Los Alamos (©Theater Freiburg).

The first aria, sung by the American Faust, reflects his unconscious confession, "I cannot stop this Trinity test. Someone or something must stop me."

"Batter my heart, three person'd God; For you
As yet, but knock, breathe, knock, breathe, knock, breathe
Shine, and seek to mend;
Batter my heart, three person'd God;
That I may rise, and stand, o'erthrow me, and bend

Your force, to break, blow, break, blow, break, blow, burn, and make me new.*
*The text is borrowed from John Donne's “Holy Sonnet XIV.”

Robert, without his attributes, pipe, and hat, is grilling his steak (©Theater Freiburg)

There is no God in Doctor Atomic. Only mechanisms, deadlines, and momentum, and on-stage glowing grills with lots of meat and a pile of beercans.

With the help of beer cans, Edward Teller ponders
the most effective arrangement of uranium blocks to achieve a critical mass (©Theater Freiburg).

The countdown is imminent. Hope comes from Oppenheimer's wife, Kitty, and her fictional Native American housemaid, Pasqualita. While Kitty invokes in vain her all-encompassing love as a counterforce, Pasqualita is stylized as a high priestess of reconciliation with divine nature.

The second act starts with a refrain sung by Pasqualita. The text is taken from a traditional Tewa lullaby song, and subsequent reiterations repeat the text with the direction changed to west, east, and south:

In the north, the cloud-flower blossoms
And now the lightning flashes
And now the thunder clashes
And now the rain comes down!
A-a-aha, a-a-aha, my little one.

Indeed, the rain threatens to delay the test explosion.

Even though the ignition and explosion of the atomic bomb would have made for a spectacular musical apotheosis of the opera, Adams deliberately refrains from this expected and thus trivial end. Instead, he composed an extended orchestral countdown with a multitude of ticking or striking clocks, unnaturally stretching time.

In the composer's own words: "When the countdown finally comes into view, time slows down on stage. The characters lose themselves in their own visions and fantasies. The closer the moment of detonation approaches, the more time and space begin to blur."

"I wrestled for months with the question of how to treat the explosion. I finally decided on an extended orchestral countdown, a palette of clock sounds, some ticking, others hammering like pile drivers, each at its own tempo. Underneath this clock polyphony lies a bloodcurdling roar from loudspeakers."

©Theater Freiburg

"I created this sound from a sampled drum roll, which I played in an endless loop and processed with heavy sound filtering. At the climax, I added a cluster of recorded baby cries that cuts through the theater space like a sound meter, tearing through the darkness. As the roar subsides, all that remains is a light shower of clock strike fragments played by harp, celesta, and tuned gongs."

"As they fade away quietly, we hear the voice of a Japanese woman. She repeats sentences from Hiroshima survivors that I found in John Hersey's famous report on the immediate aftermath: 'I can't find my husband,' and, speaking to her little boy, Kasuo, 'come here.' 'Mr. Tanimoto, please, help us.' 'Please, can we have some water?'"

©Theater Freiburg

The bones of the summoned dead later end up in a mill. Oppenheimer grinds them to dust and sprinkles them over the model of the skeleton house during the countdown.

The first atomic bomb detonated on July 16 in the Jornada del Muerto (The Path of the Dead) desert in the US state of New Mexico: “We knew the world would never be the same again. A few people laughed, others cried, but most were simply silent,” Oppenheimer later recalled. He, the father of the atomic bomb, quoted from the Bhagavad Gita, “If the brilliance of a thousand suns were to explode in the sky at once, it would be like the brilliance of the Almighty.” “Now I am become Death, the destroyer of worlds.”

©IMAGO/Pond5 Images

Contributors to the Manhattan Project, Dr. Robert J. Oppenheimer in a white hat and General Leslie Groves, in uniform, at the detonation site of the Trinity atomic bomb test. On the right edge of the photo is Robert Wilson, later the director of Fermilab near Chicago, where Red Baron met him.

In his lifetime, Oppenheimer did not regret his leadership of the Manhattan Project, but rather said, “Our work has changed the conditions of human life, but what happens with these changes is the problem of governments, not scientists.”

And so Max Born rightly laments, “Science has given man tremendous power, but no guidance on how to use it.”

**

Spectacular Pink

Yesterday evening, Red Baron observed a rare meteorological phenomenon.

While I expected a red-orange sunset, the sky was pink.

Look at the photo of a "classical" sunset by a friend of mine, the gifted Photographer Margit Anhut. An orange glow over the Vosges Mountains as seen from Schauinsland, the fourth-highest mountain in the Black Forest. Note the fog in the valleys.

As the sun sets, its light travels through a thicker atmospheric layer than when it shines from the zenith.  As a physicist, I have learned that, by Raleigh scattering, short-wavelength blue and violet light is scattered out of view. Therefore, the less scattered, longer red and orange wavelengths dominate the sky.

Now, high-altitude thin and wispy cirrus clouds enter the game. These clouds are ideal for reflecting the last rays of red and orange sunlight, particularly when the sun is below the horizon. Thus, the red light is diluted and mixes with the residual blue, making the sky appear pink.

Was it more than an incident that the very evening Red Baron listened at Freiburg’s Konzerthaus to the London Symphony Orchestra playing Max Bruch’s Violin Concerto No. 1 in G minor, the soloist Arabella Steinbacher wore a spectacular pink dress?

However, this is nothing compared to the dress Arabella wears on her website.

**

Tomorrow‘s Forests?

I still recall an Umweltgespräch (environmental discussion) in Freiburg that addressed droughts and heavy rainfall. The predictions made by the speaker six years ago have essentially come true.

That's why I was fascinated when I read about two evening lectures in the series Umweltgespräche, focusing on the forests of tomorrow.

German forests have always fascinated me. In 2015, I blogged about the severe damage to forests in Germany's Mittelgebirge (medium high mountain regions), such as the Harz Mountains.

In 2020, I revisited the topic of Waldsterben. The beginning of the coronavirus pandemic was a challenging year for people, but particularly devastating for German forests.

Finally, in 2023, I learned that not only do forests surrounding a city mitigate the local climate, but individual trees within the city can also reduce heat spots.

That's why I was excited about the two lectures, whose content was contrasting and therefore made for a fascinating evening. 

Prof. Jürgen Bauhus, Chair of Silviculture at the University of Freiburg, played the skeptic and demonstrated in his lecture, "Wald im Wandel, Wandel in den Köpfen (Forest in Transition, Transition in Minds)," that the topic of forests is much more complex and multifaceted than I had previously assumed.

In contrast, Ms. Nicole Schmalfuß, head of the Freiburg Municipal Forestry Office, took a pragmatic and practical approach to the subject in her presentation "Stadt - Wald - Vielfalt (City - Forest - Diversity)."

Freiburg's Environmental Mayor, Christine Buchheit, welcomed those present and pointed out that tonight's lectures would be attended not only by Freiburg citizens, but also by participants in a specialist workshop entitled "Wald neu denken (Rethinking the Forest)" taking place in Freiburg this week.

The evening's moderator, Prof. Heiner Schanz (left), introduced Prof. Bauhus as the first speaker. The latter emphasized the balancing act he had to perform to satisfy both the citizens and the experts present with his lecture.

He then complained about the small projection screen, as the hall was overflowing with people. Many listeners had to stand in the back, where they could probably only see splashes of color. Red Baron had arrived early, managed to get a seat in the third row, and was just able to read the slides. Nevertheless, the quality of my shots of the screen you will see in the following leaves much to be desired.

Here are a few points that stood out to me and were new to me.

Prof. Bauhus presented the research approach of the Cluster of Excellence on Future Forests in Freiburg.

Feedback on risks and potential adaptation options for forests, as well as their impacts on future forest decision-making, is incorporated into forest research. These two inputs can be used to develop transformation pathways for future socio-ecological forest systems.

The drivers of change include extreme events, disturbances, interactions, targeted environmental changes, system shifts, tipping points, and societal changes. Their predictability is limited. Here are examples:

According to the German Climate Protection Act, greenhouse gas emissions (essentially carbon dioxide and methane) in the land-use ecosystem are to be reduced by 25 million tons by 2030. However, after three consecutive dry summers between 2018 and 2020, so many trees died in the low mountain ranges that the balance was ruined, and only a saving of around 1 million tons of greenhouse gases is expected by 2030.

The planting of late-flowering black cherry trees (Prunus serotina) in the Netherlands was a complete misjudgement. The species forms dense stands and suppresses the regeneration of native trees (e.g., oak or beech). Prunus serotina's leaf litter changes the soil chemistry and hinders the growth of other plants. Between 1965 and 2018, this American import spread so rapidly that to date €500 million has been spent on combating it. 

Therefore, plans and decisions on climate protection can only be made against a backdrop of great uncertainty. In the above graphic, the lower blue ecological system state will be reached when no action is taken. Although planned remedy activities point in the right direction, they are not very targeted.

Changes in forests also require changes in society, or environmental changes generally go hand in hand with social changes.

On the one hand, forests have the capacity to provide a range of ecosystem services. On the other hand, society relies on the services this ecosystem provides. The resilience of these socio-economic factors is crucial, so risks must be mitigated through adaptation and overcome through transformations.

Results of studies show that locally adapted tree species are not always the best choice for reducing greenhouse gas emissions. However, changing tree species alone does not preserve the carbon sink properties of forests either. The best approach is flexible regeneration of adapted tree species, coupled with controlled changes in their composition. A suitable selection will maintain the CO₂ balance and can even improve it.

The future utilization potential of trees can be derived from forest utilization between 2012 and 2022. This results in an 18% decrease for spruce, a 43% increase for pine, a 160% increase for oak, and a 178% increase for beech in the years up to 2037.

The second speaker of the evening was the lively Ms. Schmalfuß.

She showed that forests cover 42% of the 6,509 hectares of the city of Freiburg. The small image illustrates the drought index in Germany for the year 2024. It shows that the moisture situation in the far southwest of Germany is quite different from that in the east (indicated by the brown areas).

Here are the predictions of future droughts made in 2019.

Freiburg boasts a diverse range of forests, from mossy to mountainous, and everything in between.

Ms. Schmalfuß presented the Freiburg Forest Convention of 2020. The city forest is preserved and managed in a way that ensures and promotes all four forest functions - protection, utilization, recreation, and climate mitigation - equally.

The objectives are:

1. Permanent preservation of the city forest
2. Preservation and promotion of biodiversity and other protective functions
3. Stability through diversity
4. Sustainable timber production
5. Increased use of timber in construction (buried  CO₂)

6. Preservation and promotion of the climate protection performance of the city forest
7. Preservation and further development of the recreational function of the city forest
8. Forest and environmental education in the city forest
9. The city forest as a workplace: occupational safety and training quality
10. The Freiburg city forest as an object of research, teaching, and study

The city forest (light green) is primarily a multifunctional commercial forest. Blue areas are forests with a prominent recreational function. Purple areas are extensive and maintenance areas, while dark red areas denote decommissioned forest areas.

The equal importance of the various functions does not mean that the same goals should be pursued everywhere since the diversity of forests requires differentiation.

Forests with a long history of forestry have great potential for biotope protection. Forests with high growth rates have great potential for climate protection. Forests with high-quality wood have significant potential for commercial use, while those located near cities have substantial potential for recreational purposes.

The concepts and instruments for implementing the Freiburg Forest Convention are:

1. Systematic management control, i.e., forest management with interim reviews and annual planning
2. FSC (Forest Stewardship Council) certification
3. Near-natural forestry and the forest development type guideline
4. Long-term adaptation to climate change
5. Old and dead wood concept
6. Biodiversity action plan
7. Integration of management planning in Natura 2000 areas*
8. Regulated hunting
9. Information and guidance for forest visitors through attractive infrastructure offerings and a forest recreation map
10. Forest education in the city forest as a contribution to education for sustainable development and inclusion - offerings by the Forestry Office and Waldhaus Freiburg

*European animal and plant species protected areas

The slide on the planned management of forest facility renewal within the 10-year plan of the updated Freiburg Forest Convention was simply not legible.

Tomorrow's forests? Ms. Schmalfuß ended her lecture with an optimistic outlook:

Still forests tomorrow!

**

A Black Hole Universe?

Somebody had to do it. In an innocently sounding paper, Enrique Gaztañaga and colleagues got rid of the Lambda Cold Dark Matter model, and seiner vermaledeiten Hilfsgrößen (its dammed auxiliary quantities), dark matter and dark energy.

The standard ΛCDM model describes the Big Bang hypothesis.

Remember: Red Baron blogged about two papers that either got rid of dark matter (MOND, MOdified Newtonian Dynamics) or did away with dark energy (Timescape).

In their paper, Enrique Gaztañaga and colleagues from the University of Portsmouth ask, "What if the Big Bang wasn't the beginning? What if our Universe had emerged from something else, something more familiar and yet radically different?"

"Our calculations suggest that the Big Bang was not the beginning of everything, but rather the result of a gravitational collapse that generated a massive black hole followed by a 'bounce' inside, which means that our Universe may have emerged from the interior of a black hole formed within a larger parent universe."

"Rather than the birth of the Universe being from nothing, it is the continuation of a cosmic cycle shaped by gravity, quantum mechanics, and the deep interconnections between them."

 
Professor Gaztañaga explains, "The Big Bang model begins with a point of infinite density where the laws of physics break down. This is a deep theoretical problem that suggests the beginning of the Universe is not fully understood."

"We've questioned that model and tackled questions from a different angle - by looking inward instead of outward. Instead of starting with an expanding Universe and asking how it began, we considered what happens when an overdensity of matter collapses under gravity."

"We've shown that gravitational collapse does not have to end in a singularity (as in the Big Bang) and found that a collapsing cloud of matter can reach a high-density state and then bounce, rebounding outward into a new expanding phase."

So the collapse of an earlier universe leads to the formation of a cloud of matter, but its energy density cannot go to infinity. Why is that so?

©Sabine Hossenfelder

When matter condenses, fermions follow the Pauli exclusion principle, meaning they cannot exist simultaneously in the same quantum state. Consequently, condensed matter resists further compression.

Professor Gaztañaga continues, "Crucially, this bounce occurs entirely within the framework of general relativity, combined with the basic principles of quantum mechanics. What emerges on the other side of the bounce is a Universe remarkably like our own. Even more surprisingly, the rebound naturally produces a phase of accelerated expansion driven not by a hypothetical field but by the physics of the bounce itself."

"We now have a fully worked-out solution that shows the bounce is not only possible - it's inevitable under the right conditions. One of the strengths of this model is that it makes predictions that can be thoroughly tested. And what's more, this new model has also revealed that the Universe is slightly curved, like the surface of the Earth."

This 'Black Hole Universe' presents a radically different view of cosmic origins, grounded entirely in known physics and observations.

The ARRAKIHS* ESA space mission may answer questions and test predictions of the new model.
*Wikipedia knows: The mission is named after a planet, Arrakis, from the science fiction novel Dune. The name is a backronym of "Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys.

ARRAKIHS will detect ultra-low surface brightness structures in the outskirts of galaxies, regions where the fossil record of galaxy formation and dark matter assembly is preserved. Studying these faint features will reveal how galaxies grow and evolve. They may also hold clues to the nature of dark matter and the Universe's initial conditions, particularly if they differ from those predicted by the standard ΛCDM model.

Science remains exciting.

*

Cooling at CERN

No, I am not referring to my cooling off following a full day of service at the CERN Open Days in September 2019.

This blog refers to beam cooling, or, more precisely, stochastic cooling of particle beams in storage rings. "Cooling" will narrow the transverse momentum distribution of a bunch of charged particles by detecting momentum fluctuations and applying an appropriate correction.

View of the AA ring. Slide from Simon van der Meer's Nobel Prize lecture:
Stochastic Cooling and the Accumulation of Antiprotons

In 2025, the Museumsgesellschaft chose CERN as the plat de résistance for its traditional summer tour. During our visit to the site, we saw a special cooling facility. The building we entered is familiar to Red Baron. Here, he helped to build the AA (Antiproton Accumulator) in the late 1970s.

Simon van der Meer invented and developed the technique of stochastic cooling at CERN in the Initial Cooling Experiment (ICE).

The principle of Stochastic Cooling.
Slide from Simon van der Meer's Nobel Prize lecture

Stochastic cooling uses the electrical signals produced by particles in a "bunch "to drive an electric kicker. This will kick the bunch of particles, reducing their transverse momentum.

The circulating particles (nearly) and the electrical signal travel at the speed of light. So the correction sent along the chord reaches the kicker well in time to apply the necessary kick to the bunch of particles.
When individual kicks are applied continuously over an extended period, the average tendency of the particles to exhibit wayward momenta is reduced.

 

Note the shrinking of the beam profile with time.

Cooling times range from a second to several minutes, depending on the required cooling depth.

Many accelerators had to work together.
Slide from Simon van der Meer's Nobel Prize lecture

The technique was used to collect and cool antiprotons* in the Antiproton Accumulator (AA). They were then injected into a modification of the Super Proton Synchrotron (SPS), i.e., the Proton-Antiproton Collider (PAC), to collide with counter-rotating protons.

*Noted as p in the graphic

While Carlo Rubbia proposed and pushed for the PAC, Simon van der Meer's stochastic cooling provided the necessary tool for its success. In 1984, Carlo and Simon were awarded the Nobel Prize in Physics for the discovery of the W and Z bosons that carry the weak nuclear force.

 
The ICE ring was also instrumental in evaluating electron cooling, a technique introduced by Gersh Budker.

Electron Beam Cooling is a technique used primarily in particle accelerators and storage rings to reduce the emittance (the measure of the spread of particle positions and momenta) of a beam of charged particles, typically protons or heavy ions. Dense, parallel beams of quasi-monoenergetic electrons travel with the heavier particles over the distance of the cooling section. The protons or ions undergo Coulomb scattering in the electron "gas" and exchange momentum with it, thus reducing the space coordinates and the angles of the heavier particles.

Click graphics to enlarge.

CERN operates electron coolers in its Antimatter Decelerator (AD) and in the smaller Extra Low Energy Antiproton (ELENA) ring.

Looking down on ELENA

This is where it gets exciting, because ELENA produces antiprotons of nearly zero energy that capture a positron, forming antihydrogen atoms. This opens research on antimatter.

Does a hydrogen atom fall in a gravitational field just as quickly as an antihydrogen atom? Are there differences in the emitted spectral lines of the two species? With the current measurement accuracies, no differences have been detected so far.

The CERN computer center was the other interesting part of our visit. Here, we were impressed by the volume of data from the experiments to be processed.

On the way out, Red Baron was abruptly confronted with his past.

On Display was the first paper by Tim Berners-Lee and Robert Cailliau, which marks the beginning of the World Wide Web, the precursor to the Internet. Even today, the sequence of letters HTTP (HyperText Transfer Protocol) for calling up websites is a reminder of the HyperText Project proposed by the two CERN computer freaks, who had no idea at the time that their proposal would change the world.

Click to enlarge

I had many a cup of coffee with Robert, a wide-awake colleague who was always up for a joke. CERN's superiors looked favorably on this coffee-drinking while leaning on bar tables, as new ideas were discussed with colleagues from outside their own field.

It was a thoroughly nostalgic visit to CERN.

**