Root Privileges

Month: July 2025

  • Frugality is a toxic chalice

    From ‘Earth Imaging Satellite NISAR Exposes NASA’s Weaknesses, ISRO’s Strengths’, NDTV, July 26, 2025:

    At the end of the day, the US scientists have swallowed their pride and are sheepishly going to watch the launch of a satellite where they have invested nearly $1.15 billion. It is this exorbitant cost by NASA that should also be a reason for Americans to squirm and be uncomfortable.

    When ISRO’s Mars Orbiter Mission entered into orbit around Mars, The New York Times carried a cartoon showing a dhoti-clad man holding a cow in one hand and knocking with the other asking to be let into a room where he could sit with the world’s other major space powers. The paragraph above as well as many others in the NDTV article are simply the other side of the same coin: one cast ISRO as a frugal simpleton and the other takes exorbitant pride in ISRO’s frugality.

    If it isn’t clear by now, however, ISRO’s lower costs stem from the fact that it’s simply underfunded and its staff underpaid. ISRO has spent less than other space agencies but how similar are the corresponding missions? The organisation’s payloads are often much lighter, carry fewer instruments, and are less capable of cutting edge science. The bigger story is that ISRO is trying (and which could be even bigger if there was a long-term plan that showed how all the smaller scale attempts added up). However, it’s not that ISRO is doing what NASA is because it simply isn’t.

    There is no reason for NASA to squirm and be uncomfortable, either: the cost reflects the strength of the US dollar and the organisation of the US economy. It also accounts for NASA being responsible for receiving, processing, distributing, and archiving NISAR data for the whole world, whereas ISRO is responsible for doing the same thing only vis-à-vis India.

    The NDTV article goes on to say:

    There are many reasons behind the huge cost incurred by NASA, one of them being that most of the development of the instruments and payloads they fly are made by huge multi-national corporations and they not only need huge profits but also need to share dividends with their share-holders. ISRO, on the other hand, being a national entity does these things in-house and has no reason to pad up the cost to share profits with share-holders.

    NASA’s principal contribution to NISAR was the L-band synthetic aperture radar (SAR) and the associated avionics and the 12-m mesh antenna plus the 9-m boom holding it. All these components were made at NASA’s Jet Propulsion Laboratory, just as ISRO’s contributions onboard NISAR came from its Space Applications Centre in Ahmedabad.

    Additionally, an ISRO official said that when their scientists travel to the Jet Propulsion Laboratory in Pasadena in California, they would stay in shared $100 a day room while the NASA scientists when they travel to the UR Rao Satellite Center in Bengaluru would stay in an over $500 a day room. This automatically inflates the costs.

    We’re talking about a monetary difference of more than 10x between nine- and ten-digit figures. I highly doubt that a small group of scientists staying for N number of days in $500 rooms could make much of a difference. Even if these costs added up in the alleged manner, living comfortably in clean environs is more important than roughing it out to save pennies. I’m also tempted to say that rooms and kitchens in cheaper hotels in the US are likely cleaner than most hotels in India.

    Also, India usually makes only one instrument the one that will fly into space, while NASA makes an engineering model and flight model, which leads to doubling the cost.

    It increases the cost. However, the engineering model is a fully functional hardware unit that can be subjected to full-scale integration testing without risking the actual flight unit. Teams can also work on software development, system integration, and ground testing in parallel while the flight model is still being assembled, avoiding bottlenecks and improving the flight model’s build. If an issue arises after launch, engineers on the ground replicate the problem on the engineering model before trying fixes on the actual spacecraft — an ability that came in handy during the Boeing Starliner crewed flight test. Finally, the engineering model is subjected to more aggressive and destructive testing, and what engineers learn they use to improve the flight model, increasing the chances that it will succeed. In the end, for the additional cost, NASA is able to send better instruments to space that operate within narrower margins of error.

    The funny thing is ISRO may also have to switch to similar developmental processes in future as it embarks on more sophisticated projects, including interplanetary sample-return missions and crewed lunar landings. I hope ISRO, unlike NDTV, isn’t taking overmuch pride in its supposed frugality.

    The way human power is distributed is also very different between NASA and ISRO at the Indian space agency. In the case of NISAR, which has taken over 11 years to build, the teams at ISRO working on multiple satellites and the salaries in India also turn out to be much lower when converted into dollar terms. The top manager at ISRO also pointed out that ISRO engineers are willing to put in long hours and work over weekends, while the US contract engineers are reluctant to put in long hours.

    Don’t just convert it into dollar terms. Also check whether the values of each work-hour with respect to the national economy in the two countries are comparable. Short of that, let’s avoid such comparisons altogether.

    There’s also more than meets the eye in valorising people being “willing” to put in longer hours and to work over the weekends while diminishing a person’s reluctance to do so. In fact, there’s a thin line between a person volunteering to put in extra and a person being expected to put in extra. I’ve seen firsthand company cultures veering over time to make the latter a foundational expectation, with managers often justifying it by saying things like “this is what it takes”, “do it for the <insert cause here>”, and “if you don’t want to, you’re in the wrong industry”. It is a worker’s right to limit their working hours to the stipulated ones. If India’s satellites are cheaper because ISRO is overworking its labour force, we’re doing it wrong — and the bill will soon come due.

    The premium for insurance also adds to the costs at ISRO since the government takes the full liability and no insurance is taken. In other countries, insurance premiums can be a huge cost. Incidentally, when India launched its communication satellite using the SpaceX Falcon-9 rocket, India also took insurance.

    NISAR costs around $1.5 billion. If I’m not mistaken, launch insurance typically costs 15-25% of the total insured value, which is the cost to replace the satellite and to launch it. In this case that would be $225-375 million. After launch coverage expires (which is when the satellite completes one year in orbit), the annual in-orbit insurance usually costs 1-3% per year, which is around $15-45 million a year. Given NISAR’s expected lifetime of three years, the total insurance cost could be $255-465 million; if we go by NISAR’s design lifetime of five-plus years, it could come to $285-555 million.

    The NDTV article also calls out the irony inherent to a NASA satellite scheduled to lift off onboard a GSLV Mk-II rocket. To the uninitiated: this is deserved because the US government scuttled a deal in the early 1980s for the Soviet Union to transfer cryogenic engine technology to India. India was subsequently forced to develop the engines on its own by taking apart and studying the Soviet engines it was able to buy, ultimately building the machine that powers the third stage of the GSLV Mk-II. (Edit: updated at 8.43 pm on July 31, 2025, from “fourth” to “third” stage.) However, the narrative goes on:

    Some would say this is an irony of ironies, and some would say it is egg on the face of US.

    Unless the article could quote someone (by name) actually making these claims, the strength of language in the second half of the statement is unfounded. In fact, the author may have been better off staking the claim themselves — “I believe this is egg on the US’s face” — but even then they will have to justify how it can be reconciled with several changes in NASA’s and the US’s leadership as well as policies regarding working with ISRO/India since the 1980s.

    Rather than concern ourselves with superficial one-upmanship, we would be better off discussing the demands of the different realities of ISRO and NASA. Both organisations have made conscious choices to develop spacecraft the way they do. Their needs are different and their political-economic contexts are wildly different. Expenditure and achievement may not be directly related because material and labour costs are lower in India yet they are deeply connected to an ambition mismatch as well. In order for ISRO to contribute Rs 800 crore to a climate-focused Earth-observing mission, (i) NASA had to conceive of NISAR based on climate scientists’ inputs and (ii) spend $1.1 billion of its own for the L-band SAR and the giant antenna, without which even ISRO’s S-band SAR wouldn’t have the resolution and swath width it currently does. But to be sure: one’s ambitions are not ‘greater’ than the other’s; they’re just different.t

    It also matters that, leading up to the launch, NASA officials and scientists have embarked on a media blitz. It’s proving really easy right now to catch hold of a NASA scientist for an extended interview on NISAR — but not an ISRO scientist.

    For all these reasons, it’s always more sensible to celebrate ISRO in terms that don’t invoke rupees or by comparing and contrasting its feats with that of another space agency.

  • Physicists test if they can load antimatter on a truck

    Physicists in Europe have reported that it’s possible to transport charged particles on a truck for four hours without disturbing them in any way. This seemingly run-of-the-mill announcement, reported in Nature on May 14, actually contains within its details the possibility of “a new era of precision antimatter spectroscopy”, in the team’s words.

    This is because of how the world currently studies antimatter, an elusive form of matter with some properties switched. For example, the electron’s antiparticle is the positron: it has the same mass but behaves like the electron’s mirror image. When a particle touches its antiparticle, they annihilate each other in a flash of energy.

    Physicists study antiparticles for what they can reveal about the still-mysterious things about our universe, such as dark matter. They’re also keen to crack the baryon asymmetry problem, which had a breakthrough reported on July 16.

    The problem is that antimatter is hard to produce in a machine made entirely of matter. What little scientists already know is based on studying antiprotons and atoms of hydrogen and helium made of antiprotons and positrons at the Antimatter Factory (AMF) at CERN, the European nuclear physics research facility more famous for hosting the Large Hadron Collider. Specifically, the problem is that AMF has instruments to study antiparticles but have limited sensitivity. Antimatter particles are also very sensitive to magnetic fields and the AMF hall has other instruments that emit such energy.

    In an ideal world, physicists should be able to produce antiparticles at AMF and transport it to a lab that has very good instruments to study them. The new study delivers a proof of concept showing this is now possible.

    At the heart of their effort is a Penning trap, a device that uses a combination of electric and magnetic fields to confine charged particles in a cylindrical tube. The magnetic field is uniform and flows through the cylinder’s central axis, holding the particles together like a string of beads. The electric field is quadrupole, like two positive and two negative charges forming a square shape with alternating charges at the vertices. This field keeps the particles from drifting away.

    In their truck, the physicists used a BASE-STEP Penning trap, a special kind of trap developed by the BASE collaboration at CERN. It’s a “Penning-trap system inside the bore of a superconducting magnet that can withstand transport-related forces.” Among other features, it uses cold beryllium ions to cool the stored particles and includes precision measurement techniques to study them.

    The team first moved a trap containing a cloud of around 100 protons out of the AMF hall using a pair of overhead cranes, then loaded it on a truck and drove 3.7 km through CERN’s Meyrin campus. They hit a maximum speed of 42.2 km/hr in this run.

    The setup included magnetic shielding and a “transport frame to handle acceleration forces apart from gravity of up to 1 g in all directions”, per the paper. On the truck, the apparatus was cooled by an “internal 30-litre liquid helium tank”. The precision voltage supply, frequency generators, and a spectrum analyser were run by a “UPS with two battery units”.

    In all, the device — 2 m long, 1.6 m tall, and 0.85 m wide — weighed about 900 kg.

    “In our future planned antiproton transport experiments,” the team wrote in its paper, “the last step in the transport campaign would be the extraction of a fraction of particles from the trapped antiproton reservoir, followed by the injection of the extracted fraction into a receiver experiment. Although we do not have such a receiver available yet, we have demonstrated particle separation and extraction after returning to the experiment zone.”

    The reason for going to all this trouble with a truck is an idea in physics called CPT symmetry. The material world is made of matter and all matter is made up of subatomic particles. While physicists know a lot about the material universe, there are still many unknowns and lots of room left for physicists to explore and learn. CPT symmetry is one corner of the room.

    Each letter stands for a kind of transformation. C (charge conjugation) means switching a particle with an antiparticle. P (parity) means switching left and right, like looking in a mirror. And T (time reversal) means reversing the flow of time. In quantum field theory (the tool physicists use to understand the physical properties of subatomic particles), CPT theorem states that if you applied all three operations to a particle, physics should be the same.

    That is to say, if you studied for a physics exam and then someone applied CPT to all particles in the universe, the answers to your question paper wouldn’t change.

    CPT symmetry has a sobering history. At the dawn of quantum field theory, scientists assumed all subatomic particles conserve C, P, and T symmetries separately. Then they found that wasn’t true, so they moved the goalpost and said all particles conserve CP symmetry. An experiment in 1964 challenged this as well when physicists found particles called kaons violated CP symmetry. Finally physicists moved the goalpost even further, saying that all subatomic particles should be expected to conserve CPT symmetry.

    Since the C part of the symmetry requires swapping a particle with its antiparticle, physicists need both matter and antimatter to check if particles obey or violate CPT symmetry. The more the merrier, too: larger quantities of antimatter will make it easier to tease out any subtle effects that might point to a violation. If all such subtlety can be ruled out, CPT symmetry will hold and physicists might breathe easier.

    In the truck study, of course, the physicists only used around a hundred protons. “Although the number of stored particles was not pushed to the limit,” they explained, “the transported number would already be enough for our high-precision experiments to operate for several years. As an example, the non-destructive high-precision measurements performed in BASE … typically consume around six antiprotons per year.”

    So far, researchers have verified CPT symmetry conservation in anti-hydrogen (hydrogen atoms made of an antiproton and a positron) and anti-protonic helium (helium atoms with antiprotons). These are of course anti-atoms and are considered a type of particle called baryons.

    Baryons are the most well-known matter particles: they include protons and neutrons as well as all atoms. Your body, for example, is baryonic matter. Physicists are keen to crack the universe’s baryon asymmetry mystery, too — and the answer is expected to have to do with some particles violating CPT symmetry in a hitherto unknown way.

    The physicists wrote in their paper that their findings indicate the “next generation” of antiproton studies could reduce the uncertainty in measurements by a factor of 10 from the “present state of the art”.

    Featured image: Left: The route for the first transport demonstration through the AMF hall. Point 1 is the experiment zone from which an overhead crane moved the transport frame to point 2. At point 2, the transport frame was loaded onto a trailer and moved to point 3, where it then got picked up by the second overhead crane. Point 4 is the loading bay with the truck. Right: Road map of the Meyrin site of CERN and the GPS position data recorded during transportation. Credit: Nature 641, 871–875 (2025).

  • Quasiparticles do the twist

    Physics often involves hidden surprises in how matter behaves at the smallest scales. A fundamental property in physics is angular momentum, which describes how things spin or rotate, from planets all the way down to particles. Angular momentum is involved in many important effects like magnetism and quantum states that could one day be used in quantum computers.

    When atoms vibrate inside crystals, the vibrational energy they release is often found in multiples of discrete values, i.e. they resemble fixed packets of energy. Physicists liken these packets to particles of vibrational energy that they call phonons.

    More particularly, a phonon is a kind of emergent particle called a quasiparticle. In 2017, Vijay B. Shenoy, an associate professor at the Centre for Condensed Matter Theory at the Indian Institute of Science, Bengaluru, explained the concept to me in a way I’ve always liked to return to:

    The idea of a ‘quasiparticle’ is a very subtle one. At the risk of being technical, let me try this: An excitation is called a particle if, for a given momentum of the excitation, there is a well-defined energy. Quite remarkably, this definition of a particle embodies what we conventionally think of as a particle: small hard things that move about.

    Now, to an example. Consider a system made of atoms at a very low density. It will be in a gaseous state. Due to their kinetic energy, the atoms will be freely moving about. Such a system has particle-like excitations. These particle-like excitations correspond to the behaviour of individual atoms.

    Now consider the system at a higher density. The atoms will be strongly interacting with each other and, therefore, make up a solid. You will never “see” these atoms as low-energy excitations. There will now be new types of excitations that are made of the collective motion of atoms and which will be particle-like (since there is a well-defined energy for a given momentum). These particle-like excitations are called phonons. Note that the phonon excitation is very different from the atom that makes up the solid. For example, phonons carry sound within a solid – but when the sound propagates, you don’t have atoms being carried from place to place!

    A ‘quasiparticle’ excitation is one that is very nearly a particle-like excitation: for the given momentum, it is a small spread of energy about some average value. The manifestation is such that, for practical purposes, if you watch this excitation over longer durations, it will behave like a particle in an experiment…

    Recently, physicists predicted that phonons can themselves carry angular momentum the way physical particles like electrons do. They were predicted to do so in materials called chiral crystals, where the atoms are arranged in a spiral structure. However, in spite of the exciting prediction, nobody had directly observed this phonon angular momentum before. Proof was missing in part because measuring something so small and subtle isn’t easy. A new study in Nature Physics finally appears to have fixed this gap, reporting the first direct evidence of the effect using a well-known chiral crystal.

    Researchers from Germany and the US designed an experiment with tellurium, an element whose crystals grow in spiral shapes that wind either to the left or to the right. Since phonons are the vibrations inside a crystal, their angular momentum as they travel in curved paths through the crystal can’t be recorded directly. Instead, the researchers surmised that if all the phonons in the chiral crystal added up, they might twist the whole crystal ever so slightly, like a wind-up toy.

    So in their experiment, they heated a crystal in an uneven way in order to throw the left‑ and right‑handed phonons off balance, leaving behind a net phonon angular momentum that the whole crystal would have to offset by twisting in the opposite direction.

    To test this, the team started by growing small, pure tellurium crystals in the lab, making sure some were single crystals — i.e. with all atoms lining up the same way — and others were polycrystals, consisting of atoms lining up in random orientations. The team assumed that only the pure chiral crystals would show the new effect whereas the polycrystals wouldn’t.

    Team members then attached the crystals to minuscule cantilevers. If the crystal twisted even a small amount, the cantilever would bend, and an electrical circuit would detect and amplify the signal. Finally, they created a temperature difference between the two ends of the crystals by shining a small, focused laser light on it. This thermal gradient was expected to allow a net angular momentum to build up, if it was there.

    The team ran its tests on both types of crystals, changing the direction of the temperature gradient and running the experiment at different temperatures. In the process the team also ruled out the effects of other forces acting on the crystals, such as expansion due to heating.

    When the laser was switched on, the single-crystal tellurium samples showed a clear torque on the cantilevers while the polycrystalline samples didn’t. The torque flipped direction if the temperature gradient was reversed — a smoking gun that it was related to the handedness of the vibrations — and disappeared altogether when the laser was turned off.

    The team measured the torque to be an extremely slight 10-11 N·m, which matched theoretical predictions.

    At higher temperatures, even the pure crystals stopped displaying a torque, in keeping with the expectation that the effect only appeared below the Debye temperature — which is the temperature at which a crystal lattice has its highest vibrational quantum energy.

    More than the recent theoretical predictions, the research team’s motivation also traced back to an experiment that Albert Einstein and the Dutch physicist Wander Johannes de Haas conducted in 1915. It showed that flipping a magnetic field also made a tiny iron rod twist. Einstein and de Haas explained that this happened because the rod’s electrons had to conserve angular momentum, thus confirming that these particles had this property, an important moment in the history of physics. The researchers behind the new study similarly called what they observed the phonon Einstein-de Haas effect.

    Shenoy, however was more measured in his assessment of the new study:

    It is, in general, not unusual to have quasiparticles possessing properties of physical particles. Condensed matter physics is replete with examples, such as phonons (discussed here), magnons, density excitations in low dimensions, etc.

    What is not usual is the discussion of angular momentum in the context of phonons. As the authors emphasise, this is possible due to the noncentrosymmetric nature of tellurium. The system does not have centrosymmetry (or inversion symmetry): that is, roughly, if you flip [the crystal] ‘inside out’ it looks like an inside out image’ rather than itself. An instructive illustration is a mirror image: the mirror image of a circle is a circle (mirror-symmetric), but the mirror image of a right hand is not a right hand. Centrosymmetry is a three-dimensional version of mirror reflection. Broadly speaking, the whole report is not super surprising, but it is interesting that the scientists can measure this.

    Many of these physics papers reporting very specialised results make it a point to mention potential future applications of the underlying science. Admittedly, the pursuit of these applications, as and when they come to pass, and the commercial opportunities they create may help to fund the research. However, such speculation in papers also reinforces the idea that studies at the cutting edge are indebted (especially financially) to the future. I don’t agree with that position although I understand its grounding.

    For example, this is what the researchers behind the new study wrote in their paper (emphasis added; AM stands for ‘angular momentum’):

    … our measurements firmly establish the existence of phonon-AM in chiral crystals. Phonon-AM is the theoretical basis of chiral and topological phonons that may interact with topological fermions to create unique topological quantum states. Phonons can also transfer AM to other fundamental particles and elementary excitations allowing for novel quantum transduction mechanisms, thermal manipulation of spin, and detection of hidden quantum fields. This discovery provides a solid foundation for emergent chiral quantum states and opens a new avenue for phonon-AM enabled quantum information science and microelectronic applications.

    And this is what Shenoy had to say about that:

    I am not sure that [the finding] will have an immediate technological impact, particularly since this is a very subtle effect that requires very expensive single crystals; my guess is that this will be useful in some very specialised sensor application of some sort in the future. The authors also mention some microelectronics stuff, not sure about that. At this stage, this is firmly in the basic sciences column!

  • Sniffing out the mystery chemistry of superheavy atoms

    Remember the periodic table from your high school classroom? The table orders elements by how the valence electrons in their atoms are arranged. However, quantum physics calculations predict that in elements with atomic number greater than 103, the electrons are arranged in new, unusual ways.

    This is because these electrons move so fast that their orbits are warped, as described by Einstein’s special theory of relativity — but verifying this has been tricky. These so-called superheavy elements don’t exist in nature and must be created one atom at a time in expensive nuclear reactions. The atoms also decay within seconds or even milliseconds. Thus, traditional chemical techniques such as liquid‑liquid extraction or gas chromatography can’t directly identify the exact molecule that short-lived atoms form.

    This ambiguity has already produced contradictory results. For example, scientists have found that flerovium-114 sometimes acts like a noble gas and sometimes like a reactive metal.

    In July, researchers with the Lawrence Berkeley National Laboratory in California reported that they had developed a new technique that overcame those hurdles by combining two existing instruments: a gas-filled separator and FIONA (“for the identification of nuclide A”). The gas-filled separator can sift superheavy atoms out of a blizzard of particles. FIONA is a sequence of traps, electrostatic lenses, and a cross‑field mass spectrometer that can cool ions to near‑room temperature, manipulate them, and finally measure each ion’s mass‑to‑charge ratio.

    The findings were published in The Journal of Physical Chemistry A.

    Because truly superheavy isotopes like rutherfordium and dubnium are too scarce to use to develop new methods, the researchers used radioactive holmium as a stand‑in. Holmium can be produced fast enough to collect good data yet is rare enough to mimic superheavy elements.

    To make the isotopes, the researchers bombarded an indium target with a beam of ionised argon-40. The resulting fusion‑evaporation reactions yielded a few hundred 151Ho or 152Ho nuclei per second plus a plethora of other ions.

    A low‑pressure helium atmosphere inside the separator quickly stripped or attached electrons so that most holmium ions reached charge states of +5 or +6. The ions were then exposed to a magnetic field, which deflected the holmium ions alone by a particular degree, and in this way they were steered towards FIONA. The uninteresting ions were made to hit absorber walls.

    At FIONA, a gas catcher lowered the ions’ charged state to +1 and cooled them to room-temperature energies. Finally, they were confined by an ion trap within a millimetre‑scale volume, where they would have a lifetime of 50-100 milliseconds. This was long enough to perform chemical reactions before the superheavy atoms decayed.

    https://demuxinfo.wpcomstaging.com/2025/06/24/technical-foundation-for-a-muon-collider-laid-at-j-parc/

    At this stage, the researchers bled a stream of oxygen molecules (O2) into the trap. Each Ho⁺ ion could either stay bare or react to make HoO⁺.

    After the chosen trap time, electric pulses forced the ions to exit the trap, where a sensitive spectrometer awaited. 151Ho and 152Ho release well‐known and distinct amounts of energy when they decay and have well-known and distinct half‑lives (35 and 162 seconds respectively). The spectrometer used these details to ‘sniff’ out the specific isotope in each molecule as the molecules decayed.

    In this way, the researchers were able to identify radioactive molecules directly, one atom at a time, formed by the holmium isotopes, with no confusion from background or contaminant signals. The amount of HoO⁺ detected increased by predictable amounts in response to both longer exposure times and higher oxygen gas flow, confirming that the technique could track molecular formation rates under varying conditions.

    Importantly, the measurements confirmed that most of the holmium ions could be converted to HoO⁺ within around 50 milliseconds at higher oxygen flow rates. They also reported finding no evidence for the formation of other, unexpected holmium oxygen compounds, confirming that the main reaction product was HoO⁺.

    The findings may open the door to a direct chemistry of rare atoms. By tracking which fluorides, oxides or other ligated ions actually form and how quickly, researchers can use the gas-filled separator followed by FIONA to infer how readily the electrons in a superheavy atom access d‑ or p‑orbitals in their atoms. This information is directly tied to the element’s place in the periodic table.

    For example, observing whether RfO2+ or DbO3+ forms under standard conditions can be used to check long‑standing predictions about how superheavy atoms in group 4 and group 5 of the table behave.

    This is all the more relevant science scientists have also been developing new techniques to increase the production rate of superheavy elements. Usually, they have made these nuclei by bombarding a target element with a high-energy beam of atoms of another element.

    The traditional choice of projectile beam has been calcium-48, but of late they have been switching to the more accessible 40Ar. For example, scientists have predicted the reaction of 40Ar with berkelium-249 to be an efficient way to synthesise important superheavy nuclei like moscovium-286. Scientists have also deployed different ion beams, such as titanium-50, to strike heavy targets like plutonium-244 to produce livermorium-116 in greater quantities. Experts have expressed belief that this method is a promising path to create even heavier elements, like element 120.

    Innovations such as the development of highly-sensitive custom detector systems also allow scientists to rapidly and reliably detect single superheavy nuclei as soon as they are formed. Similarly, advances in target assembly, including multilayered targets designed to withstand more intense projectile beams, allow experiments to go on for longer and yield more superheavy nuclei. Scientists have also been using more refined models to fine-tune accelerator parameters, such as beam intensity and energy, which can improve the chances of specific nuclei forming over others.

    As production rates inch upward and techniques like FIONA become more mature, chemists can start asking finer questions. For example, which oxidation states dominate in a molecule? How strong are the ligand bonds involving superheavy elements? And do their 7p– or 6d-orbital electrons participate in chemistry the way the theory predicts?

    But before scientists can actually explore these questions, they will have to surmount some important challenges. This is because, as the researchers acknowledged in their paper, holmium is only an approximate stand-in. Actual superheavy elements will present unique challenges. For three examples: 

    First, real superheavy elements often have very short half-lives, sometimes much less than a second. This narrows the time available to produce, trap, and chemically analyse them before they decay. Second, and crucially, the technique was designed to detect only specific charge-to-mass species in each run, e.g. only HoO⁺ or Ho⁺ per measurement. As a result, unexpected molecular forms might go undetected.

    Third: the study demonstrated only relatively simple chemical reactions. Superheavy elements may form more complex, less predictable molecules or may behave uniquely, and it isn’t yet clear whether the technique can fully resolve or identify a wide variety of more complex reaction products.

  • A laser to make light of many shapes

    Lasers can produce a slender beam of light of just one wavelength. For this simple feature, they are everywhere in modern technology, from the internet to medical devices and even in entertainment as holograms. However, traditional lasers have some limitations. For example, to use them in particular applications, engineers currently use ensembles of lenses and mirrors to ‘shape’ the light.

    Scientists from Australia and China have reported in Nature a way to produce laser light in specific shapes. A laser is a device that produces intense, focused beams of light. The new device, called a metalaser, produces such light using a metasurface: ultra-thin layers made up of artificial atoms that control light in specific ways.

    By designing the metasurface carefully, the scientists could control the colour and brightness of the laser as well as the precise shape and direction of the light waves it emitted. This meant the laser could create images, focus to a point or line, and even produce special patterns like spirals or holograms, all without the need for bulky optical elements.

    The scientists created a flat surface covered with a grid of microscopic discs made of silicon nitride. Each disc had a small hole that could be rotated to a specific angle. By changing the angle of each hole, the scientists could control the phase (the position in the light wave’s cycle) of the light coming from each disc. This phase is called the geometric phase. When the laser emitted light, these various geometric phases combined to closely shape the overall wavefront.

    By the way, the geometric phase is called the Pancharatnam-Berry phase after S. Pancharatnam and Michael Berry. Pancharatnam independently discovered the geometric phase in 1956. His promising career in physics was cut disappointingly short when he died in 1969 aged only 35. Berry discovered the geometric phase in 1986. Eight years later, the British physicist George Series wrote in a special issue of Current Science dedicated to Pancharatnam that “his work received renewed attention and acclaim only after the recognition, in the eighties, that he had derived and used the concept of geometric phases in his studies of the interference of polarised light.” More here.

    Back to the study: the laser light was trapped on the metasurface by an effect called a bound state in the continuum (BIC). A BIC is a special kind of wave that, despite having enough energy to escape and spread out, remains perfectly trapped and doesn’t leak away. It’s akin to a wave that should be able to travel freely but due to conditions like interference is confined and doesn’t interact with the surrounding ‘free’ waves. BICs are also unique because they persist rather than dissipate away.

    The BIC helped keep the light focused and intense. When it was time for the metalaser to emit a laser beam, the team introduced a controlled perturbation in the structure, such as by adjusting the shape, position or orientation of the meta-atoms on the metasurface. This disturbance allowed the light to ‘leak’ into the outside world through a well-defined channel. At this point, the disks acted like small antennas, emitting light whose direction and phase depended on the holes’ rotation.

    By carefully setting the phase at each point, the scientists could make the laser beam form any pattern they wanted even as it travelled away from the surface.

    The scientists started with a glass base and added a patina of silicon nitride. Using electron-beam lithography — which is a technique like 3D printing but with electrons — they created the tiny discs and holes with precise angles. The discs were finally covered with a thin layer of dye-doped plastic that helped to amplify the emitted light. The discs were called ‘meta-atoms’ because they were essentially artificial atoms.

    First, the team pumped the metalaser to make it emit light. Pumping is an essential step in any laser. In a regular laser, a population of atoms called the gain medium is ‘pumped’ with energy to push the atoms’ electrons into an excited state. Then, when some electrons spontaneously lose the energy they absorbed earlier and become de-excited, they release photons. The presence of these photons stimulates other excited atoms to emit identical photons as they return to a lower energy state. as well. As this process repeats itself, the gain medium releases more and more photons of a fixed energy that reflect back and forth in the cavity before entering the outside world as laser light.

    The metalaser had one extra step: a separate laser pumped the metalaser’s gain medium. According to the paper, using a laser as the pump source was more efficient because its light was tuned to exactly match the energy levels required to excite the gain medium.

    By rotating the holes in the discs, the scientists could create metalasers of almost any shape: focused spots, lines, spirals, even complex images like holograms. Traditional lasers often create speckle noise — the reason holograms have that grainy look — but the metalasers could produce holograms with almost none of this noise. The results were much clearer and sharper images.

    Credit: https://doi.org/10.1038/s41586-025-09275-6

    The team also reported that the metalaser achieved a quality factor — a measure of how well it stores energy — high enough to mean the laser was producing a pure colour. The design could also be changed to produce different types of beams, including those with special polarisation (the direction in which the light waves vibrated) or orbital angular momenta (twisting light). In fact, the team wrote in its paper that their approach could be used to make programmable lasers that switch between patterns on demand.

    The metalaser setup in the new study is microscopic, per the study, and can be integrated into small devices. Since the laser itself shapes the beam, there is no need for additional mirrors, lenses or filters.

  • Found: clue to crack the antimatter mystery

    Imagine you’ve put together a torchlight. You know exactly how each part of the device works. You know exactly how they’re all connected togetger. Yet when you put in fresh batteries and turn it on, the light flickers. You take the torchlight apart, check each component piece by piece. It’s all good. The batteries are fully charged as well. Then you put it back together and turn it — and the light flickers still.

    This torchlight is the Standard Model of particle physics. It’s the main theory of its field: it ties together the various properties of all the subatomic particles scientists have found thus far. It organises them into groups, describes how the groups interact with each other, and makes predictions about particles that have been tested to extraordinary precision. And yet, the Standard Model can’t explain what dark matter is, why the Higgs boson is so light or how neutrinos have mass.

    Physicists are thus looking for ‘new physics’: a hitherto unseen part of the torchlight’s internal apparatus that causes its light to flicker, i.e. some new particle or force that completes the Standard Model, closing the gaps that the current crop of particles and forces haven’t been able to.

    This search for new physics received a boost yesterday when the physicists working with one of the detectors of the Large Hadron Collider reported that they had observed CP violations in baryons. This phenomenon is required to explain why the universe has more matter than antimatter today even though it was assumed to have been born with equal quantities of both. Baryons are particles made up of three quarks, like protons and neutrons.

    CP symmetry is the idea that the laws of physics should be the same if you swap all particles with their antiparticles and flip left and right, like looking in a mirror. Thus CP violation in baryons means if swapped a baryon with the corresponding anti-baryon and swapped left and right, the laws of physics won’t be the same, i.e. the laws treat matter and antimatter differently.

    I wrote about this finding and its implications — including its place in the Sakharov conditions and what the results mean for the Standard Model — for The Hindu. Do read it.

    I’ve found it’s one of those things you don’t read because it has anything to say about saving money or living longer. By reminding you that there’s a natural universe out there worth exploring and discovering and that it contains no sign or imprint of the false justifications humans have advanced for their crimes, perhaps it can help you live better. As I’ve said before, if you’re not interested in particle physics, that’s fine. But remember that you can be.

    Featured image: A view of the LHCb detector at the LHC as seen through a fisheye lens. Credit: CERN.

  • Watch the celebrations, on mute

    Right now, Shubhanshu Shukla is on his way back to Earth from the International Space Station. Am I proud he’s been the first Indian up there? I don’t know. It’s not clear.

    The whole thing seemed to be stage-managed. Shukla didn’t say anything surprising, nothing that popped. In fact he said exactly what we expected him to say. Nothing more, nothing less.

    Fuck controversy. It’s possible to be interesting in new ways all the time without edging into the objectionable. It’s not hard to beat predictability — but there it was for two weeks straight. I wonder if Shukla was fed all his lines. It could’ve been a monumental thing but it feels… droll.

    “India’s short on cash.” “India’s short on skills.” “India’s short on liberties.” We’ve heard these refrains as we’ve covered science and space journalism. But it’s been clear for some time now that “India’s short on cash” is a myth.

    We’ve written and spoken over and over that Gaganyaan needs better accountability and more proactive communication from ISRO’s Human Space Flight Centre. But it’s also true that it needs even more money than the Rs 20,000 crore it’s already been allocated.

    One thing I’ve learnt about the Narendra Modi government is that if it puts its mind to it, if it believes it can extract political mileage from a particular commitment, it will find a way to go all in. So when it doesn’t, the fact that it doesn’t sticks out. It’s a signal that The Thing isn’t a priority.

    Looking at the Indian space programme through the same lens can be revealing. Shukla’s whole trip and back was carefully choreographed. There’s been no sense of adventure. Grit is nowhere to be seen.

    But between Prime Minister Modi announcing his name in the list of four astronaut-candidates for Gaganyaan’s first crewed flight (currently set for 2027) and today, I know marginally more about Shukla, much less about the other three, and nothing really personal to boot. Just banal stuff.

    This isn’t some military campaign we’re talking about, is it? Just checking.

    Chethan Kumar at ToI and Jatan Mehta have done everyone a favour: one by reporting extensively on Shukla’s and ISRO’s activities and the other by collecting even the most deeply buried scraps of information from across the internet in one place. The point, however, is that it shouldn’t have come to this. Their work is laborious, made possible by the fact that it’s by far their primary responsibility.

    It needed to be much easier than this to find out more about India’s first homegrown astronauts. ISRO itself has been mum, so much so that every new ISRO story is turning out to be an investigative story. The details of Shukla’s exploits needed to be interesting, too. The haven’t been.

    So now, Shukla’s returning from the International Space Station. It’s really not clear what one’s expected to be excited about…

    Featured image credit: Ray Hennessy/Unsplash.

  • A blog questions challenge

    I hadn’t checked my notifications on X.com in a while. When I did yesterday, I found Pradx had tagged me in a blog post called “a challenge of blog questions” in March. The point is to answer a short list of questions about my blogging history, then tag other bloggers to carry the enterprise forward. With thanks to Pradx, here goes.

    Why did you start blogging in the first place?

    I started blogging for two reasons in 2008. I started writing itself when I realised it helps me clarify my thoughts, then I started publishing my writing on the web so I could share those thoughts with my friends in different parts of the world. My blog soon gave me a kind of third space on the internet, a separate world I could escape to as I laboured through four years of engineering school, which I didn’t like at the time.

    What platform are you using to manage your blog and why did you choose it? Have you blogged on other platforms before?

    I’ve blogged on Xanga, Blogspot, Typed, Movable Type, various static site generators, Svbtle, Geocities, Grav, October, Mataroa, Ghost, and WordPress. And I’ve always found myself returning to WordPress, which — despite its flaws — allows me to have just the kind of blog I’d like to in terms of look, feel, spirit, and community. The last two are particularly important. Ghost comes a close second to WordPress but it’s too magaziney. The options to host Ghost are also (relatively) more expensive.

    Earlier this year, Matt Mullenweg of Automattic tested my support for WordPress.com with his words and actions vis-à-vis his vendetta against WP Engine but the sentiments and conversations in the wider WordPress community encouraged me to keep going.

    How do you write your posts? For example, in a local editing tool, or in a panel/dashboard that’s part of your blog?

    I used to love WordPress’s Calypso interface and its WYSIWYG editor both on desktop and mobile and used to use that to compose posts. But then WordPress ‘upgraded’ to the blocks-based Gutenberg interface, which made composing a jerky, clunky, glitchy process. At that point I tried a combination of different local editors, including Visual Studio Code, iA Writer, and Obsidian.md. Each editor provided an idiosyncratic environment: e.g. VS Code seemed like a good environment in which to compose technical posts, Obsidian (with its dark UI) for angry/moody ones, and iA writer for opinionated ones with long sentences and complex thoughts.

    Then about three years ago I discovered MarsEdit and have been using it for all kinds of posts since. I particularly appreciate its old-school-like interface, that it’s built to work with WordPress, and the fact that it maintains an offline archive of all the posts on the blog.

    When do you feel most inspired to write?

    I’ve answered this question before in conversations with friends and every time my answer has prompted them to wonder if I’m lying or mocking them.

    When I feel most inspired to write is not in my control. I’ve been writing for so long that it’s become a part of the way I think. If I have a thought and I’m not able to articulate it clearly in writing, it’s a sign for me that the thought is still inchoate. In this paradigm, whenever I have a fully formed thought that I think could help someone else think about or through something, I enter a half-trance-like state, where my entire brain is seized of the need to write and I’m only conscious enough to open MarsEdit and start typing.

    In these circumstance my ability to multi-task even minor activities, like typing with one hand while sipping from a mug of tea in the other, vanishes.

    Do you publish immediately after writing, or do you let it simmer a bit as a draft?

    That depends on what I’m writing about. When I draft posts in the ‘Op-eds’ or ‘Science’ categories, I’m usually more clear-headed and confident about my post’s contents, and publish as soon as the post is ready. For ‘Analysis’ and ‘Scicomm’ posts, however, I distract myself for about 30 minutes after finishing a draft and read it again to make sure there aren’t any holes in my arguments.

    I also have a few friends who peer-review my posts if I’m not sure I’ve articulated myself well or if I’m not able to think through the soundness of my own arguments by myself (usually because I suspect there’s something I don’t know). Four of the most frequent reviewers are Thomas Manuel, Srividya Tadepalli, Mahima Jain, and Chitralekha Manohar.

    In all these cases, however, I do read the post a couple times more after it’s finished to fix grammar and clumsy sentence constructions.

    What’s your favorite post on your blog?

    No such thing. 🙂

    Any future plans for your blog? Maybe a redesign, a move to another platform, or adding a new feature?

    I’m not keen on major redesigns. There are too many WordPress themes available off the shelf and for free these days. I change my blog’s theme depending on my mood. I don’t think it makes a difference to whether or how people read my posts. I think those that have been reading will continue to read. The text is paramount.

    I don’t see myself moving to another platform either. If anything, I might move from WordPress.com to a self-hosted setup in future but it’s not something I’m thinking of right now.

    I am currently in the process of removing duplicated posts in the archives — at last count I spotted about 20. Many posts are also missing images I’d added at the time of publishing, mostly because they were associated with a domain that I no longer use. I need to fix that.

    A few years ago I lost around 120 posts after someone managed to hack my account when the blog was hosted with a provider of cPanel hosting services. I maintain a long-term backup of all my posts on a Backblaze dump. I’m still in the process of identifying which posts I lost and retrieving them from the archive.

    So yeah, focusing on this clean-up right now.

    Who’s next?

    This is embarrassing: I only know a few other bloggers. I stopped keeping track after many bloggers I’d been following in the early years just stopped at some point. Right now, of those blogs I still follow, Jatan and Pradx have already been nominated for this ‘challenge’. So let me nominate Suvrat Kher and Dhiya Gerber next, both of whom I think will have interesting answers.

    Featured image credit: Chris Briggs/Unsplash.

  • Sharks don’t do math

    From ’Sharks hunt via Lévy flights’, Physics World, June 11, 2010:

    They were menacing enough before, but how would you feel if you knew sharks were employing advanced mathematical concepts in their hunt for the kill? Well, this is the case, according to new research, which has tracked the movement of these marine predators along with a number of other species as they foraged for prey in the Pacific and Atlantic oceans. The results showed that these animals hunt for food by alternating between Brownian motion and Lévy flights, depending on the scarcity of prey.

    Animals don’t use advanced mathematical concepts. This statement encompasses many humans as well because it’s not a statement about intelligence but one about language and reality. You see a shark foraging in a particular pattern. You invent a language to efficiently describe such patterns. And in that language your name for the shark’s pattern is a Lévy flight. This doesn’t mean the shark is using a Lévy flight. The shark is simply doing what makes sense to it, but which we — in our own description of the world — call a Lévy flight.

    The Lévy flight isn’t an advanced concept either. It’s a subset of a broader concept called the random walk. Say you’re on a square grid, like a chessboard. You’re standing on one square. You can move only one step at a time. You roll a four-sided die. Depending on the side it lands on, you step one square forwards, backwards, to the right or to the left. The path you trace over time is called a random walk because its shape is determined by the die roll, which is random.

    Random walk 2500.svg.

    There are different kinds of walks depending on the rule that determines the choice of your next step. A Lévy flight is a random walk that varies both the direction of the next step and the length of the step. In the random walk on the chessboard, you took steps of fixed lengths: to the adjacent squares. In a Lévy flight, the direction of the next step is random and the length is picked at random from a Lévy distribution. This is what the distribution looks like:

    Levy0 distributionPDF.svg.

    Notice how a small part of each curve (for different values of c in the distribution’s function) has high values and the majority has smaller values. When you pick your step length at random from, say, the red curve, you have higher odds of of picking a smaller step length than a longer one. This means in a Lévy flight, most of the step lengths will be short but a small number of steps will be long. Thus the ‘flight’ looks like this:

    Sharks and many other animals have been known to follow a Lévy flight when foraging. To quote from an older post:

    Research has shown that the foraging path of animals looking for food that is scarce can be modelled as a Lévy flight: the large steps correspond to the long distances towards food sources that are located far apart and the short steps to finding food spread in a small area at each source.

    Brownian motion is a more famous kind of random walk. It’s the name for the movement of an object that’s following the Wiener process. This means the object’s path needs to obey the following five rules (from the same post):

    (i) Each increment of the process is independent of other (non-overlapping) increments;

    (ii) How much the process changes over a period of time depends only on the duration of the period;

    (iii) Increments in the process are randomly sampled from a Gaussian distribution;

    (iv) The process has a statistical mean equal to zero;

    (v) The process’s covariance between any two time points is equal to the lower variance at those two points (variance denotes how quickly the value of a variable is spreading out over time).

    Thus Brownian motion models the movement of pollen grains in water, dust particles in the air, electrons in a conductor, and colloidal particles in a fluid, and the fluctuation of stock prices, the diffusion of molecules in liquids, and population dynamics in biology. That is, all these processes in disparate domains evolve at least in part according to the rules of the Wiener process.

    Still doesn’t mean a shark understands what a Lévy flight is. By saying “sharks use a Lévy flight”, we also discard in the process how the shark makes its decisions — something worth learning about in order to make more complete sense of the world around us rather than force the world to make sense only in those ways we’ve already dreamt up. (This is all the more relevant now with #sharkweek just a week away.)

    I care so much because metaphors are bridges between language and reality. Even if the statement “sharks employ advanced mathematical concepts” doesn’t feature a metaphor, the risk it represents hews close to one that stalks the use of metaphors in science journalism: the creation of false knowledge.

    Depending on the topic, it’s not uncommon for science journalists to use metaphors liberally, yet scientists have not infrequently upbraided them for using the wrong metaphors in some narratives or for not alerting readers to the metaphors’ limits. This is not unfair: while I disagree with some critiques along these lines for being too pedantic, in most cases it’s warranted. As science philosopher Daniel Sarewitz put it in that 2012 article:

    Most people, including most scientists, can acquire knowledge of the Higgs only through the metaphors and analogies that physicists and science writers use to try to explain phenomena that can only truly be characterized mathematically.

    Here’s The New York Times: “The Higgs boson is the only manifestation of an invisible force field, a cosmic molasses that permeates space and imbues elementary particles with mass … Without the Higgs field, as it is known, or something like it, all elementary forms of matter would zoom around at the speed of light, flowing through our hands like moonlight.” Fair enough. But why “a cosmic molasses” and not, say, a “sea of milk”? The latter is the common translation of an episode in Hindu cosmology, represented on a spectacular bas-relief panel at Angkor Wat showing armies of gods and demons churning the “sea of milk” to producean elixir of immortality.

    For those who cannot follow the mathematics, belief in the Higgs is an act of faith, not of rationality.

    A metaphor is not the thing itself and shouldn’t be allow to masquerade as such.

    Just as well, there are important differences between becoming aware of something and learning it, and a journalist may require metaphors only to facilitate the former. Toeing this line also helps journalists tame the publics’ expectations of them.

    Featured image credit: David Clode/Unsplash.

  • The hidden heatwave

    A heatwave is like the COVID-19 virus. During the pandemic, the virus infected and killed many people. When vaccines became available, the mortality rate dropped even though the virus continued to spread. But vaccines weren’t the only way to keep people from dying. The COVID-19 virus killed more people if the people were already unhealthy

    In India, an important cause for people being unhealthy is the state itself. In many places, the roads are poorly laid, kicking dust exposed by traffic use up into the air, where it joins the PM2.5 particles emitted by industrial facilities allowed to set up shop near residential and commercial areas without proper emission controls. If this is one extreme, becauses these experiences are so common for so many Indians, at the other is the state’s apathy towards public health. India’s doctor-to-patient ratio is dismal; hospitals are understaffed and under-equipped; drug quality is so uneven as to be a gamble; insurance coverage is iffy and unclear; privatisation is increasing; and the national government’s financial contribution towards public health is in free fall.

    For these reasons as well, and not just because of vaccine availability or coverage, the COVID-19 virus killed more people than it should have been able to. A person’s vulnerability to this or any other infection is thus determined by their well-being — which is affected both by explicit factors like a new pathogen in the population and implicit factors like the quality of healthcare they have been able to access.

    A heatwave resembles the virus for the same reason: a person’s vulnerability to high heat is determined by their well-being — which in turn is affected by the amount of ambient heat and relative humidity as well as the extent to which they are able to evade the effects of that combination. This weekend, a new investigative effort by a team of journalists at The Hindu (including me) has reported just this fact, but for the first time with ground-zero details that people in general, and perhaps even the Tamil Nadu government itself, have thus far only presumed to be the case. Read it online, in the e-paper or in today’s newspaper.

    The fundamental issues are two-pronged. First, Tamil Nadu’s policies on protecting people during heatwaves require the weather department to have declared a heatwave to apply. Second, even when there is no heatwave, many people but especially the poorer consistently suffer heatwave conditions. (Note: I’m criticising Tamil Nadu here because it’s my state of residence and equally because it’s one of a few states actually paying as much attention to economic growth as it is to public health, of which heat safety is an important part.)

    The net effect is for people to suffer their private but nonetheless very real heatwave conditions without enjoying the support the state has promised for people in these conditions. The criticism also indicts the state for falling short on enforcing other heat-related policies that leave the vulnerable even more stranded.

    The corresponding measures include (i) access to clean toilets, a lack of which forces people — but especially women, who can’t urinate in public the way men are known to — to drink less water and suppress their urges to urinate, risking urinary tract infections; (ii) access to clean and cool drinking water, a paucity of which forces people to pay out of their pockets to buy chilled water or beverages, reducing the amount of money they have left for medical expenses as well as risking the ill health that comes with consuming aerated and/or sugary beverages; and (ii) state-built quarters that pay meaningful attention to ventilating living spaces, which when skipped exposes people to humidity levels that prevent their bodies from cooling by sweating, rendering them more susceptible to heat-related illnesses.

    And as The Hindu team revealed, these forms of suffering are already playing out.

    The India Meteorological Department defines a heatwave based on how much the temperature deviates from a historical average. But this is a strictly meteorological definition that doesn’t account for the way class differences create heatwave-like conditions. These conditions kick in as a combination of temperature and humidity, and as the report shows, even normal temperature can induce them if the relative humidity is higher and/or if an individual is unable to cool themselves. The state has a significant role to play in the latter. Right now, it needs to abandon the strictly meteorological definition of heatwaves in its policy framework and instead develop a more holistic sociological definition.

    Featured image credit: Austin Curtis/Unsplash.