- Why in news
- On 6 January 2026, the Ministry of Science & Technology said JNCASR researchers had run the first supercomputer simulations of ice formation that reproduce the Mpemba effect in water.
- What it is
- The Mpemba effect is the observation that hot water can sometimes freeze faster than colder water. It is named after Erasto Mpemba, who rediscovered it in the last century, though Aristotle had noted something similar. It belongs to nonequilibrium physics, which studies how systems relax after sudden changes.
- Who did it
- Researchers at JNCASR, an autonomous institute under the Department of Science and Technology, ran the simulations.
- Mechanism proposed
- Cooling water can get stuck in short-lived intermediate molecular arrangements before true ice grows. Different starting temperatures get stuck for different lengths of time.
- Nucleation path
- Hotter water can sometimes take a quicker path to nucleation, the birth of ice, and so avoid the delays that colder water faces.
- Beyond water
- The effect can also appear in fluid-to-solid transitions in systems other than water. Models shown include the TIP4P/Ice water model, the 2D Lennard Jones model and the Potts model.
- Possible applications
- The work may help in understanding out-of-equilibrium phenomena, thermal control in next-generation electronics and better cooling strategies.
Don’t confuse with Mpemba effect vs. supercooling: The Mpemba effect compares freezing times of hot and cold water. Supercooling is when a liquid stays liquid below its freezing point, which is a separate idea.
Science and technology: 57 Prelims questions since 2013; most test the concept behind the news, not the news itself. In Mains, 12 news-triggered questions.
Why it matters
- Gives the first computational evidence for a long-debated paradox, helping the study of nonequilibrium physics.
- May inform thermal management in electronics and cooling design.
Problems
- Water simulations are computationally demanding, and the effect is still debated at the experimental level.
Way forward
- Test the simulation findings through careful experiments and extend the study to other materials.
Put in your answer
Indigenous research example: JNCASR, an autonomous institute of DST, used supercomputers for a basic science problem, showing the role of computing in research.
No close past question yet.
No practice question for this one; the card may still help an answer. Why: Concept-based science topic. Prelims asks sci_tech concepts (36 of 57 questions test the concept), but this is a niche research result unlikely to be set.
Worth revising until Prelims 2027: most news questions come within two years of the event.