
Albert Einstein had foreseen that nuclear energy would secure the energy needs of the world, or that it could be quite dangerous. In 1939, Einstein and other scientists wrote a famous letter to Franklin D. Roosevelt explaining that a nuclear chain reaction in uranium could release vast amounts of power and might soon become possible.
We have now moved on from the gloomy days of the Manhattan Project. Today, nuclear reactors generate about 10% of the world’s electricity, mostly using fuel like Uranium-235. Highly advanced technologies such as Fast Breeder Reactor could potentially expand this share in the future possibly to 25 - 30% by creating more consumable fuel while producing power, allowing nuclear energy to supply a larger portion of clean electricity globally.
How is nuclear energy produced?
Nuclear energy is produced through Nuclear Fission. In this process, atoms of fuel such as Uranium‑235 split when struck by neutrons, releasing a large amount of heat and more neutrons. It is like a domino effect on a large basis at a microscopic scale. The heat released is used to boil water into steam, which spins turbines connected to generators to produce electricity—similar to how thermal power plants work, but the heat source is nuclear rather than coal or gas.

What is Nuclear Criticality?
Nuclear criticality is the point at which a nuclear chain reaction becomes self-sustaining. In a reactor, atoms of fuel (usually uranium or plutonium) split during fission and release neutrons. When each fission event causes exactly one more fission on average, the reaction stays stable and continues producing energy steadily. This balanced state is called criticality, and it is carefully controlled inside nuclear reactors using control rods and moderators.
Why is it difficult?
Achieving Nuclear Criticality is difficult because it requires quite an advanced technology to produce and handle fissile fuels like Uranium-235 or Plutonium-239, along with extremely precise reactor engineering to control the Nuclear Chain Reaction safely. It demands huge investments, large Uranium or Thorium reserves, and decades of scientific expertise.
What is a breeder reactor?
A breeder nuclear reactor is designed to create more usable nuclear fuel than it burns. It converts abundant but non-fissile materials like Uranium‑238 or Thorium‑232 into fissile fuels such as Plutonium‑239. Because of this fuel-breeding capability, breeder reactors can dramatically extend nuclear fuel resources and are considered important for long-term nuclear energy strategies. In principle: a breeder reactor can produce more fissile fuel than it consumes.
What could be the future share of nuclear energy?
Many energy projections suggest that nuclear could rise to 25 - 30% of global electricity if countries expand reactors and adopt advanced designs like breeder reactors and small modular reactors. Nuclear energy is attractive because it produces large amounts of power with very low carbon emissions. It can support large-scale electricity, thorium energy, hydrogen production, industrial heat, desalination, and low-carbon power systems.





Albert Einstein is widely regarded as the greatest physicist of all time. Einstein won the Nobel Prize in 1921 for explaining the photoelectric effect - using Planck's quantum theory. But many argue (rightly) that he deserved a few more Nobel Prizes for works such as relativity, Bose Einstein condensate, etc.
However, there were times when even the genius of Einstein failed to comprehend the complexity of the universe. Einstein's debate with Niels Bohr are still remembered for how wrong Einstein's stance was on the uncertainty principle by Heisenberg. Till the end of his life, Einstein never made peace with the cornerstone of quantum mechanics.
Following are 10 notable times Albert Einstein was “wrong” (or
at least incomplete) in physics - not in a mocking sense, but in the very
human way. The lesson here is that even Einstein was wrong on many occasions so don't beat yourself up in life!
Einstein added a term (Λ) to his equations to force a static
universe, because he believed the universe couldn’t be expanding. Later, Edwin Hubble showed the universe is expanding. Einstein visited Hubble's observatory to confirm the discovery himself. Ironically, his biggest blunder Λ came back decades later as dark energy.
Einstein hated the idea that nature is fundamentally probabilistic. His famous line - God does not play dice with the universe, confirmed Einstein's opposition to the growing interest in quantum mechanics. Bohr famously replied to Einstein - Don't tell God what to do. And experiments later proved that quantum randomness is real, not just due to hidden ignorance.
Einstein strongly opposed Bohr’s Copenhagen
interpretation, which says that tiny particles (like electrons) exist in a fuzzy mix of all possible states (like being in many places at one time) until we measure or observe them. The act of observing forces them to "pick" or "collapse" to just one state. Modern quantum mechanics overwhelmingly supports Bohr, not Einstein.

Einstein was looking for the ultimate theory, the theory of everything being his life goal. He believed that quantum mechanics must be incomplete and
that hidden variables would restore determinism. Bell’s Theorem and later experiments (Aspect, Zeilinger, etc.) ruled out
local hidden-variable theories.
Quantum entanglement is when two or more tiny particles get linked, sharing the same fate no matter how far apart they are. Einstein called entanglement: “Spooky action at a distance”. He believed it showed quantum theory was flawed. Today, entanglement is experimentally verified and used in quantum computing and cryptography.
Einstein first predicted gravitational waves (1916), then
later doubted their existence, publishing a paper arguing they weren’t
real. Einstein thought that gravitational waves were merely mathematical artifacts or too weak to detect. He eventually corrected himself and in 2015, LIGO directly detected them.
Einstein was skeptical that real objects, that too stars way more massive than the Sun, could collapse into
singularities. He even wrote a paper arguing black holes wouldn’t form in reality. Today, black holes are directly observed, including the first image
in 2019.
Einstein never fully accepted or contributed meaningfully to quantum field theory, which became the backbone of modern particle physics (Standard Model).
In order to find theory of everything, Einstein spent the last ~30 years of his life trying to unify gravity and electromagnetism. He failed, and his approach turned out to be mathematically elegant but physically unproductive.
Einstein initially believed nuclear energy would remain
theoretical. Gradually he came to realize with the advent of world wars that nuclear energy could be detrimental for the world. Einstein himself admitted he had underestimated its real-world implications and wrote a letter to Roosevelt not to create atomic weapons.

1. Despite giving his name to Boson and Bose-Einstein statistics, he never won a Nobel Prize, which is one of the biggest ironies in science history.
2. An impressed Albert Einstein personally translated Bose’s 1924 paper into German and submitted it for publication, leading to the discovery of Bose Einstein condensate.
3. Bose was a brilliant student throughout his academic career. He ranked first in M.Sc. Mathematics at Calcutta University in 1915.
4. Bose had no formal training in advanced quantum mechanics when he derived Bose–Einstein statistics—he arrived at it purely through intuition and symmetry.
5. Bose never received a PhD, yet became a professor and Fellow of the Royal Society (FRS).
6. The term “boson” was coined by Paul Dirac, not Bose himself, to honor Bose’s contribution to physics. Dirac and his wife Margit visited Calcutta in the 1950s.
7. Bose worked closely with Meghnad Saha, and together they translated Einstein’s and Minkowski’s papers into English for Indian students.
8. Bose played a key role in building modern science education in India, especially at Dhaka University and later Calcutta University after division.
9. Bose was nominated for the Nobel Prize multiple times, but the prize committee preferred experimental discoveries over theoretical ones.
10. Bose openly admitted he did not fully grasp how revolutionary his own result was—it was Einstein, not Bose, who immediately realized the importance and applied Bose's theory to matter, thus discovering fifth state of matter.