Reviews of topical problems

V.V. Brazhkin “Ultrahard nanomaterials: myths and reality” Phys. Usp. 63 523–544 (2020)

V.N. Dolgunin, A.N. Kudi, M.A. Tuev “Mechanisms and kinetics of gravity separation of granular materials” Phys. Usp. 63 545–561 (2020)

V.E. Panchuk, Yu.Yu. Balega, V.G. Klochkova, M.E. Sachkov “Study of exoplanets by spectroscopic methods” Phys. Usp. 63 562–582 (2020)

Physics of our days

V.I. Dokuchaev, N.O. Nazarova “Silhouettes of invisible black holes” Phys. Usp. 63 583–600 (2020)

Methodological notes

V.I. Ritus “Generalization of the k coefficient method in relativity to an arbitrary angle between the velocity of an observer (source) and the direction of the light ray from (to) a faraway source (observer) at rest” Phys. Usp. 63 601–610 (2020)

A.S. Dzarakhokhova, N.P. Zaretskii, A.V. Maksimychev, L.I. Men’shikov, P.L. Menshikov “Identity of the mechanisms of Weibel and Alfvén-cyclotron plasma instabilities” Phys. Usp. 63 611–616 (2020)

N.S. Kardashev, I.D. Novikov, S.V. Repin “Wormholes with entrances close to each other” Phys. Usp. 63 617–621 (2020)

Personalia

Yu.Yu. Balega, L.I. Gurvits, R.D. Dagkesamanskii, L.M. Zelenyi, K.I. Kellermann, Yu.Yu. Kovalev, N.N. Kolachevsky, A.A. Konovalenko, V.G. Kurt, I.D. Novikov, Yu.N. Pariiskii, A.M. Cherepashchuk “In memoria of Nikolai Semenovich Kardashev” Phys. Usp. 63 622–624 (2020)

Physics news on the internet

Yu.N. Eroshenko “Physics news on the Internet (based on electronic preprints)” Phys. Usp. 63 625–627 (2020)