Below are a couple of paragraphs that caught my attention:
“Scientific understanding and scientific discovery are both important aims in science. The two are distinct in the sense that scientific discovery is possible without new scientific understanding….
…..to design new efficient molecules for organic laser diodes, a search space of 1.6 million was explored using ML and quantum chemistry insights. The top candidate was experimentally synthesized and investigated. Thereby, the authors of this study discovered new molecules with very high quantum efficiency. Whereas these discoveries could have important technological consequences, the results do not provide new scientific understanding.”
The authors provide two more examples of a similar kind, from different branches of science.
The authors conclude:
“Undoubtedly, advanced computational methods in general and in AI specifically will further revolutionize how scientists investigate the secrets of our world. We outline how these new methods can directly contribute to acquiring new scientific understanding. We suspect that significant future progress in the use of AI to acquire scientific understanding will require multidisciplinary collaborations between natural scientists, computer scientists and philosophers of science. Thus, we firmly believe that these research efforts can — within our lifetimes — transform AI into true agents of understanding that will directly contribute to one of the main goals of science, namely, scientific understanding.”
Nice.. thanks for sharing, will go through it. Although a lot of brute force seems to be passed off as understanding these days (brawn = brain?) I wonder if AI and ML of the varieties we have today are advancements in computing or intelligence?
My reply:
The computational capability is undoubtedly great, and probably the coding/software domain has been conquered, but there is a tendency to extrapolate the immediate impact of AI to every domain of human life, where even basic tech has not made an impact. That needs deeper knowledge of interfacing AI with other domains of engineering. Embedding AI in the virtual domain is one thing, but to put it in the real world with noise is a different game altogether. That needs interfacing with the physical world, and there is also an energy expense that doesn’t get factored into the discussion. It has great potential, and I’m eager to see its impact on the physical infrastructure. Parallelly, it is interesting to see how it has been sold in the public domain.
If you need to admire complex analysis for its elegance and visual utility, try quantum optics. Specifically, the description of quantum states. Thanks to creation and annihilation operators, the position and momentum states of a quantum optical field can be represented as quadratures. These entities can now be represented on the orthogonal axes of a complex plane. The representation of Argand diagrams starting with a classical electromagnetic field and then extrapolating them to quantum theory is a tribute to its geometrical representation. The fact that two axes can be utilized to represent real and imaginary parts of the defined state is itself an interesting thing. By certain operations within the plane, one can realize the vacuum state, the coherent state, and the squeezed state of quantum optics.
The Vacuum Spread – One of the major consequences of quantum theory, and especially the second quantization, is the realization of the vacuum states. Even when there are zero photons, there is a residual energy in the system that manifests as vacuum states. How to define the presence or absence of a photon is a different proposition because vacuum states are also associated with something called virtual photons. That needs a separate discussion. Anyway, in a complex plane of quadrature, a vacuum state is represented by a circular blob and not a point (see fig. 1). It is the spread of the blob that indicates the uncertainty. In a way, it is an elegant representation of the uncertainty principle itself because the spread in the plane indicates the error in its measurement. Importantly, it emphasizes the point that no matter how low the energy of the system is, there is an inherent uncertainty in the quadrature of the field. This also forms the fundamental difference between a classical and a quantum state. The measurement of the vacuum fluctuation is a challenging task, but one of the most prevalent consequences of vacuum fluctuation is the oblivious spontaneous emission. If one looks at the emission process in terms of stimulated and spontaneous pathways, then the logical consequence of the vacuum state becomes evident in some literature on quantum optics. Spontaneous emission is also defined as stimulated emission triggered by vacuum state fluctuations. It is an interesting viewpoint and helps us to create a picture of the emission process vis-à-vis the stimulated emission.
Figure 1. Vacuum state representation. Note that their centre is at the origin and has a finite spread across all the quadrants. Figure adapted from ref. 2.
Another manifestation of the vacuum state is the Casimir effect, where an attractive force is induced as you bring two parallel plates close to each other. The distance being of the order of the wavelength or below this triggers a fascinating phenomenon which has deep implications not only in understanding the fundamentals of quantum optics and electrodynamics, but also in the design and development of quantum nanomechanical devices.
A shift in the plane – Coherent states are also described as displaced vacuum states, and this displacement is evident in the Argand diagrams. The quadrature can now help us visualize the uncertainty in the phase and the number of photons in the optical field. One of the logical consequences of the coherent state is the number-phase uncertainty. This gets clear if one observes the spread in the angle of the vector and the radius of the blob represented (see Fig. 2). Notice that the blob still exists. The only difference is that the location of the blob has shifted. The consequence of this spread has a deeper connection to the uncertainty in the average number of photons and the phase of the optical field. The connection to the number of photons is through the mod alpha, which essentially represents the square root of the average number of photons. Taken together, the blob in the Argand diagram represents the number-phase uncertainty.
Figure 2. Coherent state representation. Note that their centre is displaced. Figure adapted from ref. 2.
Lasers are the prototypical examples of coherent states. The fact that they obey Poissonian statistics is the direct consequence of the variance in the photon number, which is equivalent to the square root of the average number of photons. This means one can use photon statistics to discriminate between sources that are sub-Poissonian, Poissonian, or super-Poissonian in nature. The super-Poissonian case is the thermal light, and the sub-Poissonian state represents photon states whose number can reach up to 1 or 0. The coherent states sit in the middle, obeying the Poissonian statistics.
Everything has a cost – Once you have a circle with a defined area, it will be interesting to ask: Can you ‘squeeze’ this circle without changing its area? The answer is yes, and that is what manifests as a squeezed state. In this special state, one can squeeze the blob along one of the axes at the cost of a spread in the orthogonal direction. This converts the circle into an ellipse (see Fig. 3).
Figure 3. Squeezed State. Note the circle has been squeezed into an ellipse. Figure adapted from ref. 2.
Note that the area must be conserved, which means that the uncertainty principle still holds good; just that the reduction in the uncertainty along one axis is compensated by the increment in another. This geometrical trick has a deep connection to the behaviour of an optical field. If one squeezes the axis along the average number of photons, it means that you are able to create an amplitude-squeezed state. This means the uncertainty in the counting of photons in that state has reduced, albeit at the cost of the uncertainty in the measurement of phase. Similarly, if one squeezes the blob along the axis of the phase, then we end up with a lowering of the uncertainty for the optical phase. Of course, this comes at the cost of counting of number of photons. I should mention that the concept of optical phase itself is not clearly defined in quantum optics. This is because an ill-defined phase can have a value of 2π, which creates the problem. An interesting application of the phase-squeezed quantum states is in interferometric measurements. By reducing the uncertainty in the phase, one can create highly accurate measurements of phase shifts. So much so that this can have direct implications on high-precision measurements, including gravitational wave detection. The anticipation is also that such tiny shifts can be helpful in observing feeble fluctuations in macroscopic quantum systems.
Pictures can lead to more than 1,000 words. And if you add them to a quantum optical description, as in the case of the states that I have defined, they create a quantum tapestry. Perhaps this is the beauty of physics, where there is a coherence between mathematical language, geometrical representation, and physical reality. Feynman semi-jokingly may have said, “Nobody understands quantum mechanics,” but he forgot to add that there is great joy in the process of understanding through mathematical pictures. After all, he knew the power of diagrams.
References:
Ficek, Zbigniew, and Mohamed Ridza Wahiddin. Quantum Optics for Beginners. 1st edition. Jenny Stanford Publishing, 2014.
Fox, Mark. Quantum Optics: An Introduction. Oxford Master Series in Physics 15. Oxford University Press, 2006.
Gerry, Christopher C., and Peter L. Knight. Introductory Quantum Optics. Cambridge, United Kingdom ; New York, NY, 2024.
Saleh, B. E. A., and M. C. Teich. Fundamentals of Photonics. 2nd edition. Wiley India Pvt Ltd, 2012.
Recently, anthropic co-founder Jared Kaplan, who has a background in physics, made the following comment, which was circulated on X. Below is the excerpt:
Below is my response:
A Remarkable Human Being = Remarkable Attribute(s) + Human Being
The first term in the RHS can be replaced by AI, but not the second term, for the following reasons.
Machines, including AI, can surely change the way humans think, work and live, but it will be difficult to match human connection. A machine can enhance human life, but can it inspire a human life?
People inspire people. Ask a child or any adult who inspires them. It will generally be a fellow human being. Machines add value, but human beings represent a valuable life. We utilize the former, and get inspired by the latter. It is this inspiration that propels people forward to do things that may further turn out to be remarkable. This contribution is not easily quantified, but it is hard to gauge a human life without inspiration.
People like Ed Witten, Ashoke Sen and Terry Tao add value to humanity not only through their work and ideas, but their lives show that human beings can think and do something remarkable. It assures human beings that, individually, our species can do something good. Human beings derive meaning by interacting with fellow human beings and are inspired by the interaction. They also get inspired and draw meaning by studying people from the past. A human’s search for meaning and purpose is always in the background of other human beings. We are 8 billion plus, and it is hard to ignore each other.
It will be very unusual to find a serious student of theoretical physics who says I am inspired to live by ‘ChatGPT’.
Probably a young Kaplan, too, was inspired by a fellow human being! So, my question to Mr. Kaplan. Who inspired you to do physics?
A small sampling of Raman’s publication. These papers are related to light scattering and form the foundation on which he made his famous discovery. Raman wrote more than 400 research papers in his lifetime (apart from monographs, lectures and public talks). Writing such a series of papers on a particular topic can be observed throughout his career.
A note to young scholars: intellectual monuments are built this way: thought after thought, day after day, paper after paper. Never underestimate what can be achieved with consistent, honest effort.
In reference to a recent article on higher education in the Economic Times, a well-known tech entrepreneur and philanthropist wrote the following on X/Twitter: “75% of Indian higher education institutions still not industry-ready. Lot of work left to transform. But the 21st century requires education, research, innovation, and startups as four pillars of a university.”
This is a thought I do support, but I think there is one more important meta-pillar, perhaps a ‘foundation’ on which all these pillars are standing, and that is called ethics. Below are five aspects of ethics that I think need further attention.
If one observes some of the major contemporary and pressing problems in our world, they can be connected to the ethical aspects of how humans function. A vital part of our educational system should re-emphasize this connection and make it central to everything that is done in a society.
Ethics has two important elements to it: first, it has a philosophical grounding and connects to how humans function in a society. Second, it has an important connection to how trust in a society can be developed. Most of the discussions on ethics generally focus on the first element from a morality perspective, whereas the second point has an equally important utility and an economic connection.
Ethical principles have great utility. It is important that we never keep it as an implicit aspect of human endeavour. Instead, we should start everything on the ethical grounds and build it up from there, including businesses, because a strong ethical foundation probably would be the best thing to happen for economic progress in any society, because trust is so important among human beings, and it is one thing that probably brings humans together. In the long run, the meaning of ‘prosper’ critically depends on the meaning of ethics. Being prosperous without being ethical is detrimental to any human pursuit. Zero-sum games are exciting, but in the limit of many games, the number of people who lose will be far more than the people who win. Instead, cooperative games have much larger dividends to all players and are inherently connected to a concept called as double thank you moment.
The philosophy of ethics is something which the world has to revisit in greater detail, especially in an era where technological implications are driving human life in directions which we have not anticipated. One may think that raising ethical issues might hinder progress, but my argument here is that, instead of hindrance, one should look at it as an important requisite for human societies to not only survive but also to flourish. Large human endeavours cannot sustain without trust, and that trust is reinforced through ethical behaviour.
Without ethical implications being factored in, it would be hard to really design anything related to technology. A case in point is the social media restrictions in countries such as Australia. Technology has the amazing capability to move fast before the philosophical debates can come in, but it does not mean that philosophy has to be completely ignored. The downstream of a scientific idea can become a product in a market, and positively impact society, but this evolution has a fellow-traveller, and that is ethics. The feedback loop is incomplete without the ethical considerations, and therefore, it should be looked at as an important ingredient in any human design.
There is an inherent connection between cooperation and trust, and that is founded on an ethical principle. The world requires an ethical recap, and it should be part of individuals, institutions, and governments. There is a rich history of ethics in all the cultures across the world, and it is worth revisiting them in a new light. Perhaps it is high time that we “Make Ethics Great Again.”
Yesterday evening (10th Jan 2026), Shubhanshu Shukla, the recent Indian astronaut, was at IISER Pune as part of the ‘India Science Festival’. There was a huge crowd gathered to see and listen to him. Within IISER, it is rare to see such a massive gathering for a science event, and it was heartening to witness this on a Saturday evening. Thanks to schools and colleges in Pune, science and science-related activities get traction from the people of Pune (especially younger people). They enthusiastically participate in many events related to science.
Such a gathering is very important for at least three reasons:
It connects a scientifically oriented person to the public and thereby connects them to science.
It showcases that there is some science-related activity happening within the Indian scene.
It sends out a message to people that icons can be created out of people who do science funded by the public.
I would want to emphasize four other points:
Scientific icons are as good as the science they represent. A major part of the credit should go to the organizations that supported and trained him, and this includes ISRO, NASA and the Indian Air Force.
To put an astronaut in space, it takes a lot of effort at various levels of society. Public support is vital for such an effort. Public icons such as Shubhanshu Shukla are a good representation of what investment in science can do to the morale of the public, especially for young people.
The created momentum should not be lost, given that recognizable people, such as astronaut Shubhanshu Shukla, have made an imprint on young people. This should be followed up with measures to recruit them for science and technology.
Space science and technology, astronomy and astrophysics have always been among the most fascinating domains to attract people into science. Many Indian scientists and a past astronaut, Rakesh Sharma, have played an important role in this pursuit. One should not forget them.
Let me conclude with a word of appreciation for Pune city. It is not a capital city, but its enthusiasm for intellectual pursuits is high, and it attracts a lot of enterprising people (recently, there was a public policy conference that had some amazing people). If it can get a lift in its public infrastructure, it can create its own path in the landscape of science and technology.
VISMAYA - History & Philosophy of Physics 