6 January 2026·PIB

Supercomputer simulation of ice formation gives evidence of paradoxical phenomenon of water

In this note

1. At a Glance

Mpemba effect = paradoxical phenomenon where hotter water freezes faster than colder water, eluding rigorous proof for centuries [1][2].
Indian scientists at JNCASR (Bengaluru), an autonomous institute of DST, produced the first supercomputer simulation of ice formation validating the effect, published in Communications Physics (Nature group) [1][2].
UPSC relevance: GS-III (Sci-Tech indigenous R&D), Prelims (institutions, phenomena, scientists), and as a high-yield current-affairs item for January 2026.

6 January 2026 — PIB/DST announced the publication of the first molecular-dynamics simulation of the Mpemba effect in water by a JNCASR team [1][2].
Research appeared in Communications Physics (DOI 10.1038/s42005-025-02251-6) [2].

Aristotle (~4th century BCE) recorded in Meteorologica: "the fact that water has previously been warmed contributes to its freezing quickly" [1][2].
1963 — Tanzanian schoolboy Erasto B. Mpemba observed hot ice-cream mix freezing faster; rediscovered with Dr. Denis Osborne, giving the effect its modern name [1].
Decades of contested experiments followed; computational proof for water itself remained elusive due to the demanding nature of water simulations [1].
2026 — JNCASR team delivers the first conclusive simulation evidence in water [1][2].

Lead institution: Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru — autonomous institute under Department of Science & Technology (DST) [2].
Units involved: Theoretical Sciences Unit & School of Advanced Materials, JNCASR [1].
Researchers: Soumik Ghosh, Purnendu Pathak, Sohini Chatterjee, Prof. Subir K. Das (corresponding) [1][2].
Journal: Communications Physics (Nature Portfolio) [2].
Parent ministry: Ministry of Science & Technology, Government of India [1].
Phenomenon class: Out-of-equilibrium relaxation / non-monotonic cooling.
Mechanism revealed: Cooling water gets stuck in intermediate metastable molecular arrangements; hotter water can bypass these delays and reach nucleation of ice faster [2].

Scientific / Technological

Resolves a 2,300-year-old paradox using molecular-dynamics simulations [1].
Confirms Mpemba effect occurs not only in water but also during other fluid-to-solid (first-order) phase transitions [1].
Showcases India's HPC (high-performance computing) capability for fundamental physics.

Economic / Applications

Potential redesign of cooling strategies for industries (refrigeration, food preservation) [1].
New approach to thermal management in next-generation electronics where heat dissipation is a bottleneck [1].
Implications for materials relaxation engineering under sudden temperature shifts [1].

Administrative / R&D Ecosystem

Highlights role of DST autonomous institutes in cutting-edge basic research [2].
Aligns with India's National Supercomputing Mission emphasis on indigenous HPC use.

Historical

Continuum from Aristotle → Francis Bacon → Descartes → Mpemba (1963) → JNCASR (2026) [1].

6 Jan 2026 — PIB release: JNCASR team publishes first supercomputer simulation of Mpemba effect in water [1].
2025 — Paper accepted in Communications Physics (s42005-025-02251-6) [2].

Mpemba effect = hotter water freezing faster than colder water [1].
Named after Erasto Mpemba of Tanzania, who observed it as a schoolboy in 1963 [1].
Earliest written reference: Aristotle's Meteorologica [1][2].
Indian institute behind 2026 breakthrough: JNCASR, Bengaluru [2].
JNCASR is an autonomous institute under the Department of Science and Technology (DST) — not under MeitY or DAE [2].
Corresponding author: Prof. Subir K. Das [2].
Published in journal Communications Physics (Nature Portfolio) [2].
Mpemba effect is an example of an out-of-equilibrium relaxation phenomenon [1].
Mechanism: water trapped in metastable intermediate molecular states during slow cooling [2].
Applications cited: thermal control in next-generation electronics and improved cooling strategies [1].
The effect is also seen in other systems undergoing first-order phase transitions [1].

GS Paper III — Science & Technology: "Developments and their applications and effects in everyday life" / "Indigenisation of technology and developing new technology."
Possible question stems:
"Discuss how indigenous high-performance computing capability is enabling India to address fundamental scientific questions, with reference to recent work on the Mpemba effect."
"The Mpemba effect, long considered a curiosity, has practical implications for thermal management. Examine."
"Evaluate the role of DST's autonomous institutes in advancing basic research in India."

National Supercomputing Mission (NSM) — backbone of India's HPC infrastructure.
PARAM Siddhi-AI / PARAM Rudra supercomputers — indigenous HPC platforms.
JNCASR, IISc, TIFR, IIA — DST/DAE autonomous institutes lineage.
Anomalous properties of water (density max at 4°C, hydrogen bonding) — physical chemistry overlap.
Phase transitions & nucleation theory — Prelims physics basics.
India's R&D expenditure (GERD) — context for science policy.
Anusandhan National Research Foundation (ANRF) — successor to SERB, funding basic science.

JNCASR is under DST, not under MeitY or DAE (a common confusion with IISc/TIFR funding) [2].
Mpemba was a Tanzanian student, not a professor; effect named after the student, not the physicist Denis Osborne [1].
Effect concerns freezing time, not freezing temperature — hotter water does NOT freeze at a higher temperature.
Journal is Communications Physics (Nature Portfolio), not Nature Physics or Physical Review Letters [2].
The PIB note misspells "Meteorologica" as "Meterological"; the source is Aristotle's Meteorologica [1].