What Is Nuclear Criticality? How Much Clean Energy Can It Produce?

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.

10 Reasons Every Physics Student Should Watch Project Hail Mary

Normally, one expects a science fiction movie to be intellectually demanding, "serious" and weirdly confusing. But Ryan Gosling starrer Project Hail Mary is something pleasantly different... it is a treat for everyone, not just Sheldon Cooper like science nerds. Like a breath of fresh air, Project Hail Mary successfully manages to make science feel like a fun, and thrilling survival experience.

To remind you, this is not Oppenheimer. This is no Interstellar.

Unlike many sci-fi epics that lean heavily on equations on a white board type spectacle, Project Hail Mary builds its "tension" through humorous tone, funny imagery, model building, a random eureka discovery, and the quiet brilliance of an unlikely friendship.

Ryan Gosling shines through and through. He conveniently transforms from a simpleton Ken in Barbie to Dr Grace, a goofy scientist who has given up on his own science. The movie depicts an emotional journey of his rediscovering himself, in deep and unforgiving outer space. Supporting actors also do well in their limited roles, but it is Rocky the alien that steals spotlight.

What is even more interesting is, the same writer who wrote The Martian (a technically more sound film) also wrote Project Hail Mary (a light hearted take on space). This fact alone makes Project Hail Mary worth a watch. But following are 10 more reasons why every physics student should watch the movie:

1. Relativity & interstellar travel ideas

Interstellar journeys require understanding huge distances, velocities, and time scales. The movie indirectly touches on concepts related to light speed, relativity and the challenges of traveling between stars.

2. Problem-solving like a physicist

The protagonist Dr Grace constantly breaks complex problems into smaller solvable parts. He is clumsy but manages somehow to get to results. Problem solving need not be boring or complicated, the movie conveys that one can approach difficult theoretical or experimental questions with a slight hint of funny.

3. Experimental thinking

Instead of guessing solutions, the characters design models, experiments, test hypotheses, and analyze results. This closely reflects how real science research works.

4. Accurate orbital mechanics

The movie discusses trajectories, space travel paths, and gravitational effects. How a rotating centrifuge can be used to mimic the effects of gravity. These ideas connect directly with topics students learn in classical mechanics.

5. Astrobiology and planetary science

The story explores how life might exist in very different environments. Dr Grace has a unique idea - that alien life might not require water at all for their survival and existence. Whether or not he finds such a life form in the movie you will have to find that out. But it is an idea worth exploring.

6. Shows how physics connects disciplines

The problems in the movie involve chemistry, biology, and engineering along with physics. Students see how physics acts as the foundation of all sciences, as Rutherford said... all science is either physics or stamp collecting.

7. Inspiration for students

Seeing a goofy scientist use earthly knowledge to solve alien-level problems can be motivating. It reminds students that physics (and math) are universal languages which are understood by everyone.

8. Demonstrates the scientific method

The story repeatedly shows a cycle of observation, hypothesis, testing, and revision. This mirrors the scientific method used in real research labs.

9. Scientific curiosity is central

Dr Grace finds himself in an unknown environment with a mission he wasn't supposed to be on. And yet curiosity drives him forward. Instead of fear, the main character reacts to the situation with confusion, excitement and curiosity. This reflects the mindset that drives many scientists and researchers.

10. Physics is not mathematics

Great physics does not require complicated mathematics, said Martinus J. G. Veltman and the movie stands true to this idea. Ryan Gosling or Dr Grace do not engage deeply in mathematics (other than communication) they rely heavily on observation and experiment - the foundation of physical science.

Moon Crater Named “Carroll” After Astronaut's Deceased Wife

Amid ongoing tensions in the Middle East, a ray of hope for humanity has emerged in the form of Artemis II crew, which is currently the farthest ever manned mission from Earth. If everything works, the next mission, Artemis III aims to land astronauts near the Moon’s south pole, something never done before.

But we are already witnessing history in the making as one emotional moment took the whole world by surprise when Canadian astronaut Jeremy Hansen formally made a request to name a newly discovered crater on the Moon "Carroll", after mission commander Reid Wiseman's late wife. This was followed by a teary eyed group hug.

This was not only a moment of forever love but also a symbol of incredible human strength. The astronauts have also shown how science and faith can co-exist. How some feelings can reach beyond the farthest possibilities, to the far side of the Moon and back to home planet Earth. This is exactly the right time for us as a species to look for peace, not war.

This is also the first time a non-American has traveled to the Moon’s vicinity, astronaut Jeremy Hansen from the Canadian space agency. The astronauts are setting example for future space exploration. They’ll capture ultra-high-resolution images of the Moon and Earth for navigation calibration and geological mapping.

The crew is wearing special radiation sensors because they must spend days outside Earth’s protective magnetosphere, something astronauts haven’t done since Apollo 17 in 1972. The spacecraft will loop around the Moon and naturally fall back toward Earth on April 10 without needing a major burn to return, a safety method also used in Apollo 8.

The mission spacecraft built by European Space Agency will reenter Earth’s atmosphere at about 39,000 km/h, generating temperatures near 2,800°C, testing the new heat shield design. It will test the first human mission with a hybrid international spacecraft, a US-European partnership. This is what humanity should be striving for - consistent collaboration, new discovery and adventure into outer space.

10 Times When Einstein Was Wrong About Physics

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!

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1. Cosmological Constant (his “biggest blunder”)

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.

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2. Rejection of Quantum Indeterminacy

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.

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3. Opposition to the Copenhagen Interpretation

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.

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4. Hidden Variables Belief

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.

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5. Disbelief in Quantum Entanglement

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.

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6. Incorrect Prediction About Gravitational Waves (Initially)

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.

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7. Resistance to Black Holes

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.

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8. Dismissal of Quantum Field Theory’s Direction

Einstein never fully accepted or contributed meaningfully to quantum field theory, which became the backbone of modern particle physics (Standard Model).

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9. Unified Field Theory Failure

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.

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10. Underestimating the Practical Impact of Nuclear Energy

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.

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10 Surprising Facts About Satyendra Nath Bose

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.

Nobel Prize In Physics Awarded For Quantum Mechanics

The 2025 Nobel Prize in Physics has been announced to 3 scientists from different nations, whose work has pushed quantum mechanics from a highly conceptual realm to physical devices you can actually hold. The winners are Michel Devoret (France), John Clarke (UK) and John M. Martins (USA).

Their experiments in the 1980s have bridged theory and engineering, paving the way for tomorrow’s quantum technologies, which we actually use today! In simpler terms, they showed decades ago that quantum effects, like tunnelling and discrete energy levels, can manifest in circuits large enough to be held.

What Nobel Committee Said

The Nobel Committee explained why this year's win is crucial for physics and tech world... "they have provided opportunities for developing the next generation of quantum technology, including quantum cryptography, quantum computers, and quantum sensors."

Olle Eriksson, Chair of the Nobel Committee for Physics, said:

It is wonderful to be able to celebrate the way that century-old quantum mechanics continually offers new surprises. Quantum mechanics is the foundation of all digital technology.

Nobel For Macroscopic Quantum Object

Nobel Committee noted that the winners' findings have "brought quantum mechanics from the subatomic world onto a chip."

Reaction of Nobel Laureates

The winners' comments suggest that this was unexpected and a meaningful recognition which they will cherish. John Clarke commented: "It never occurred to me that this might be the basis for Nobel prize." He almost collapsed out of surprise!

John M Martins opened his computer, and saw his picture alongside the other winners, and he was "in shock." Michel Devoret was instrumental in making long-term contributions in superconducting quantum circuits, and thankful for the recognition.

The royal society (UK) of which John Clarke is a fellow, said:

Their experiments revealed that the strange laws of quantum physics apply not only at the atomic scale, but in systems big enough to see and touch.

 

What the winners discovered

The key phenomena involved in the victory are quantum tunnelling and energy quantisation. Quantum tunneling is the phenomenon where a subatomic particle passes through a potential energy barrier that it shouldn't have enough energy to overcome, according to classical physics.

Quantum systems, like electron, can only absorb or emit energy in discrete packets (quanta). In many quantum systems, allowed energy levels are separated by well defined gaps; energy transitions happen when quantum systems, like electron, jump between energy levels.

The breakthrough of the laureates was to show that these effects, long thought to be limited to atoms, molecules or small particles, can appear in macroscopic — i.e. large — systems when engineered correctly.

To study the two phenomena, they carefully controlled parameters like current, voltage, and temperature, and measured the electrical behavior of the circuit which they built using superconducting materials. And all of this was done in the mid 1980s! Their pioneering work led to the technologies in the devices we use today, and will use tomorrow.

How Nobel winners are selected

The Nobel Prizes were established through the will of Alfred Nobel, a scientist, engineer and industrialist, who died in 1896 and left instructions that the bulk of his enormous fortune be used to found annual prizes in Physics, Chemistry, Physiology or Medicine, Literature, and Peace.

Alfred Nobel and Nobel Prize

Nobel Prize in physics is awarded every year, usually announced in early October. For each year’s Nobel Prize, the nomination process begins in the previous year.

Nomination forms are sent out anonymously to select individuals in the field, around 3000 reputed scientists, in September. They nominate candidates for the coveted prize before Jan 31 deadline, but they cannot nominate themselves.

The Nobel committee reduces the nominee list to a shortlist (often ~15 names) and eventually proposes up to three laureates for the prize. In the earlier days, the prize was also given to a single person as well.

Summing up

The 2025 Nobel Prize in Physics is a reminder that quantum mechanics is not just a set of bizarre formulas for electrons, but a living framework that can manifest in engineered devices. Clarke, Devoret, and Martinis converted quantum phenomena into electrical circuits, closing the gap between theory and practicality.

In awarding this prize, the Nobel Committee highlights that years of careful research in basic physics can lead to major technological change. It shows that big breakthroughs often start as simple questions explored with patience in the physics lab.