SPOTLIGHT

QUANTUM SUNLIGHT

In a recent experiment, researchers have succeeded in using sunlight to demonstrate quantum interference and entanglement between two photons generated 150 million km apart, from vastly different sources[1]. A dramatic optical effect, that can be explained only through quantum mechanics, has been known since quite some time: When two indistinguishable photons enter a beam splitter simultaneously, they undergo quantum interference, which results in both of them bunching together, and always exiting from the same beam splitter port [2]. Now, a team of researchers have shown that similar quantum interference effects can be seen even when one of the photons arise from a distant thermal source – the sun – while the other photon is generated in a controlled setting, from a semiconductor quantum dot inside a laboratory. The researchers further generated entanglement between the photons from the two incredibly different sources, and showed that such states violate the Bell inequality [1], a test which disproves local realism [3]

42 IS THE ANSWER TO LIFE, THE UNIVERSE AND EVERYTHING

Can you express 1 as sum of cubes of three integers? That’s trivial! 13 + 03 + 03 = 1. May be without 0s? 93 + (-6)3 + (-8)3 = 1! There are many, in fact, infinitely many such possibilities. How about finding integers (x,y,z) such that x3 +y3 +z3 =2? Not so straightforward, is it? It is not easy to find (x,y,z) such that x3 +y3 +z3 =k, for any natural number k without computers. This is almost a 65-year old problem. (See [1] and references within for the history) Naturally, this is still an open problem for all natural numbers k. Number theorists, however, had solved for all k up to 100, except for 33 and 42. Andrew Booker [1] figured a beautiful answer for 33 with his new algorithm as: 33 = 88661289752875283 + (−8778405442862239)3 + (−2736111468807040)3 On 6th of September 2019, using Charity Engine, he and Andrew Sutherland solved for 42: 42 = (−80538738812075974)3 +804357581458175153 +12602123297 3356313 And, “...the only remaining unsolved cases up to a thousand are 114, 165, 390, 579, 627, 633, 732, 906, 921, and 975.”

CORNEA FROM SKIN CELLS!

Raising hope of millions around the world, Japanese scientists recently reported the first successful transplantation of human cornea (protective outer layer of the eye) generated from human skin cells. This remarkable achievement is through a technique known as “induced pluripotent stem (iPS) cells”- where adult cells collected from a human donor is first reprogrammed into an embryonic state (embryonic-like cells). These embryonic-like cells can then be transformed into various other cell types in the body such as nerve, liver, heart, and corneal cells. Japanese stem-cell biologist Dr. Shinya Yamanaka, at Kyoto University, discovered the iPS technique and won the Nobel prize in 2012 for this work. Although this technique has tremendous potential to treat a range of disease conditions, the efforts to translate it from the laboratory to the clinic are so far dawdling. In the above case the patient has a disease that damaged her corneal cells- a condition that makes vision blurry and can even lead to blindness. To treat her, Ophthalmologist Dr. Kohji Nishida and his team from Osaka University, Japan, created sheets of new corneal cells using iPS cells generated from skin cells. After the treatment the woman’s cornea remained clear with significant improvement in vision. Currently, the world over, similar treatments are done using corneal cells collected from eyes of donors who have died and there is a huge disparity between requirement and availability. Hence, this groundbreaking work holds a great amount of potential.

2020 BREAKTHROUGH PRIZE IN MATHEMATICS WINNER

Alex Eskin, a mathematician at the University of Chicago, has been awarded the 2020 Breakthrough Prize in Mathematics. Citation: For revolutionary discoveries in the dynamics and geometry of moduli spaces of Abelian differentials, including the proof of the “magic wand theorem” with Maryam Mirzakhani. Alex teamed with the famous Iranian mathematician and Fields Medalist, Maryam Mirzakhani, who tragically passed away in 2017, to prove a theorem about dynamics on moduli spaces. The result was published in 2013 and has many consequences. One addresses the longstanding problem: If a beam of light from a point source bounces around a mirrored room, will it eventually reach the entire room – or will some parts remain forever dark? After addressing the problem in the purest abstract setting, the two mathematicians were able to show that for polygonal rooms with angles which are fractions of whole numbers, only a finite number of points would remain unlit

A NEW C18 CARBON ALLOTROPE DISCOVERED BY CHEMISTS

First-ever Single Ring Shaped Molecule of Pure Carbon Element carbon (“C”) is perhaps the only one element in the periodic table of elements which can form number of stable allotropes, of which, diamond, graphite, graphene, carbon nanotubes, and fullerenes are a few notable allotropes. These allotropes have been widely studied and established their bonding and structural details. The discovery of fullerenes has sparked the scientists for intense explorations of such allotropes due to their technological applications in material sciences, electronic industry and nanotechnology. In addition to the above species, the family of elusive “cyclo[n]carbons” (Cn ) have created considerable interest and fascinated experimentalists and theoreticians for widespread explorations in their chemical synthesis, understanding of their bonding situation and structural aspects. It has remained as an immense challenge for decades from the synthetic chemistry point of view, not only due to their inherent high reactivity but also due to the lack of proper starting precursors with which a chemical synthesis could be designed. It has been a puzzling question for chemists about the kind of bonding situation and how are the carbon atoms connected in these species. Diederich et al. in 1989, first time showed the gas phase formation of the neutral cyclo[18]carbon from a stable precursor by the mass spectroscopic technique.[1] Shortly, in 1990, the same group had first time showed the preparation of multimetallic hexacobalt carbonyl complex featuring the cyclo[18]carbon species. [2] This is the first limited structural evidence in which the C18 species could be stabilized in the coordination sphere of a transition metal. Very recently (August 2019), two research groups led by K. Kaiser and L. M. Scriven have achieved the isolation of cyco[18]carbon (C18) first time which was prepared in a stepwise manner consisting of a series of chemical reactions.[3] They have used scanning tunneling microscopy and atomic force microscopy to synthesize the C18 molecule on a sodium chloride surface. The microscopic image investigations revealed that the C18 molecule exhibit polyynic type structure containing alternative carbon-carbon single (C-C) and triple bonds (CΞC) in a single 18 membered ring. The skeletal structure of the C18 is very much contrasting when compared with the other molecular allotropes of the carbon such as the laboratory isolated fullerenes. The latter allotropes are composed of five and six membered carbon rings with carbon-carbon single (C–C) and double bonds (-C=C-). Another most distinctive feature of C18 is that it contains sp-hybridized carbon atoms with two perpendicular pi-conjugated electronic distribution. The discovery of cyclo[18]carbon by the authors K. Kaiser and L. M. Scriven, can certainly be a landmark finding in the chemistry of carbon family of the periodic table of elements. This landmark discovery may pave the way for many more fundamental discoveries in unraveling new chemical species which were so far only observed in the vapor phase. It can be envisaged that the cyclo[18]carbon (C18) might display interesting properties and find numerous applications in the material science and nanotechnology.