Space & Physics
The physics of the mysterious Hall effect
In the first article of Ed Publica’s series on the Hall effect, condensed matter physicist Dr. Saraubh Basu, explains the physics of the Hall effect, which has reaped fruits for condensed matter physics research over the past century.

It was in 1879, when the Hall effect was observed in the laboratory for the first time. Then 23-year-old Edwin Hall’s work then led to various avatars of his eponymous effect being discovered. Previously unknown properties inherent in semiconductors among other materials, were now unraveled to the physicist’s eyes.
Unfortunately for Hall, who died in 1938, he never won the Nobel Prize for his work, despite three Noble prizes and a ‘Science Breakthrough Prize’ were awarded over the past century.
But to physicists, the Hall effect has fundamentally advanced our understanding about the properties of electronic systems.
For one, the Hall effect has enabled calculations of the fine structure constant, α ∼ 1/137. This quantity is of paramount importance in quantum mechanics and electromagnetism, for measuring the strength in the interactions that electrically charged particles such as electrons and muons, have with light particles (or photons).
For another, there are various other related discoveries, for example, the role of topology and geometry, fractional statistics, non-abelian anyons among others that have constantly enriched our knowledge in the field of condensed matter physics.
In the rest of this article, I shall set the stage with Edwin Hall’s anecdote into his seminal discovery which marked the period high of his career, to probe the various ‘avatars’ of the Hall effect.
What is the Hall effect?
Hall first came across the concept of a current carrying wire experiencing a mechanical force in presence of a magnetic field, while attending his supervisor Henry Rowland’s lectures.

Edwin Hall. Credit: Wikimedia
But he stumbled upon a fact that the direction of the electric current (beyond certain transient phenomena) remained insensitive to the presence of the magnetic field.
Hall disagreed with this, assured that the force experienced by the charges is proportional to the magnetic field, with the geometry of the conductor does not play any role. Rowland offered him the problem of investigating the effect of a magnet on the current flowing in a fixed conductor for his doctoral dissertation.
Hall found the appearance of a voltage perpendicular to the flow of electric current, while under the presence of a perpendicularly positioned and intense magnetic field. This is now called the Hall voltage. Also, the longitudinal resistivity of the wire, now dubbed Hall resistivity, turned out to be insensitive to the magnitude field.

A schematic diagram depicting the Hall effect. Credit: Karthik / EdPublica (modified from Wikimedia diagram)
But what Hall observed is attributed the classical Hall effect. Again, this is just one of the various avatars of the Hall effect that have been discovered during this period.
In 1980, the ‘integer’ quantum Hall effect was observed, with the ‘fractional’ avatar observed just later in 1982. Thereafter, the anomalous Hall effect, the spin Hall effect along with its quantum counterpart – the quantum spin Hall effect that were discovered by different groups of researchers.
All of these novel findings have significantly influenced our understanding of the material properties, particularly those of the semiconductors.
In the next series of articles, I shall shed light onto the intriguing physics of these various avatars …
Space & Physics
MIT unveils an ultra-efficient 5G receiver that may supercharge future smart devices
A key innovation lies in the chip’s clever use of a phenomenon called the Miller effect, which allows small capacitors to perform like larger ones

A team of MIT researchers has developed a groundbreaking wireless receiver that could transform the future of Internet of Things (IoT) devices by dramatically improving energy efficiency and resilience to signal interference.
Designed for use in compact, battery-powered smart gadgets—like health monitors, environmental sensors, and industrial trackers—the new chip consumes less than a milliwatt of power and is roughly 30 times more resistant to certain types of interference than conventional receivers.
“This receiver could help expand the capabilities of IoT gadgets,” said Soroush Araei, an electrical engineering graduate student at MIT and lead author of the study, in a media statement. “Devices could become smaller, last longer on a battery, and work more reliably in crowded wireless environments like factory floors or smart cities.”
The chip, recently unveiled at the IEEE Radio Frequency Integrated Circuits Symposium, stands out for its novel use of passive filtering and ultra-small capacitors controlled by tiny switches. These switches require far less power than those typically found in existing IoT receivers.
A key innovation lies in the chip’s clever use of a phenomenon called the Miller effect, which allows small capacitors to perform like larger ones. This means the receiver achieves necessary filtering without relying on bulky components, keeping the circuit size under 0.05 square millimeters.

Traditional IoT receivers rely on fixed-frequency filters to block interference, but next-generation 5G-compatible devices need to operate across wider frequency ranges. The MIT design meets this demand using an innovative on-chip switch-capacitor network that blocks unwanted harmonic interference early in the signal chain—before it gets amplified and digitized.
Another critical breakthrough is a technique called bootstrap clocking, which ensures the miniature switches operate correctly even at a low power supply of just 0.6 volts. This helps maintain reliability without adding complex circuitry or draining battery life.
The chip’s minimalist design—using fewer and smaller components—also reduces signal leakage and manufacturing costs, making it well-suited for mass production.
Looking ahead, the MIT team is exploring ways to run the receiver without any dedicated power source—possibly by harvesting ambient energy from nearby Wi-Fi or Bluetooth signals.
The research was conducted by Araei alongside Mohammad Barzgari, Haibo Yang, and senior author Professor Negar Reiskarimian of MIT’s Microsystems Technology Laboratories.
Society
Ahmedabad Plane Crash: The Science Behind Aircraft Take-Off -Understanding the Physics of Flight
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:

On June 12, 2025, a tragic aviation accident struck Ahmedabad, India when a regional passenger aircraft, Air India flight A1-171, crashed during take-off at Sardar Vallabhbhai Patel International Airport. According to preliminary reports, the incident resulted in over 200 confirmed casualties, including both passengers and crew members, and several others are critically injured. The aviation community and scientific world now turn their eyes not just toward the cause but also toward understanding the complex science behind what should have been a routine take-off.
How Do Aircraft Take Off?
Take-off is one of the most critical phases of flight, relying on the precise orchestration of aerodynamics, propulsion, and control systems. Here’s how it works:
1. Lift and Thrust
To leave the ground, an aircraft must generate lift, a force that counters gravity. This is achieved through the unique shape of the wing, called an airfoil, which creates a pressure difference — higher pressure under the wing and lower pressure above — according to Bernoulli’s Principle and Newton’s Third Law.
Simultaneously, engines provide thrust, propelling the aircraft forward. Most commercial jets use turbofan engines, which accelerate air through turbines to generate power.
2. Critical Speeds
Before takeoff, pilots calculate critical speeds:
- V1 (Decision Speed): The last moment a takeoff can be safely aborted.
- Vr (Rotation Speed): The speed at which the pilot begins to lift the nose.
- V2 (Takeoff Safety Speed): The speed needed to climb safely even if one engine fails.
If anything disrupts this process — like bird strikes, engine failure, or runway obstructions — the results can be catastrophic.

Environmental and Mechanical Challenges
Factors like wind shear, runway surface condition, mechanical integrity, or pilot error can interfere with safe take-off. Investigators will be analyzing these very aspects in the Ahmedabad case.
The Bigger Picture
Take-off accounts for a small fraction of total flight time but is disproportionately associated with accidents — approximately 14% of all aviation accidents occur during take-off or initial climb.
Space & Physics
MIT claims breakthrough in simulating physics of squishy, elastic materials
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters

Researchers at MIT claim to have unveiled a novel physics-based simulation method that significantly improves stability and accuracy when modeling elastic materials — a key development for industries spanning animation, engineering, and digital fabrication.
In a series of experiments, the new solver demonstrated its ability to simulate a diverse array of elastic behaviors, ranging from bouncing geometric shapes to soft, squishy characters. Crucially, it maintained important physical properties and remained stable over long periods of time — an area where many existing methods falter.
Other simulation techniques frequently struggled in tests: some became unstable and caused erratic behavior, while others introduced excessive damping that distorted the motion. In contrast, the new method preserved elasticity without compromising reliability.
“Because our method demonstrates more stability, it can give animators more reliability and confidence when simulating anything elastic, whether it’s something from the real world or even something completely imaginary,” Leticia Mattos Da Silva, a graduate student at MIT’s Department of Electrical Engineering and Computer Science, said in a media statement.
Their study, though not yet peer-reviewed or published, will be presented at the August proceedings of the SIGGRAPH conference in Vancouver, Canada.
While the solver does not prioritize speed as aggressively as some tools, it avoids the accuracy and robustness trade-offs often associated with faster methods. It also sidesteps the complexity of nonlinear solvers, which are commonly used in physics-based approaches but are often sensitive and prone to failure.
Looking ahead, the research team aims to reduce computational costs and broaden the solver’s applications. One promising direction is in engineering and fabrication, where accurate elastic simulations could enhance the design of real-world products such as garments, medical devices, and toys.
“We were able to revive an old class of integrators in our work. My guess is there are other examples where researchers can revisit a problem to find a hidden convexity structure that could offer a lot of advantages,” Mattos Da Silva added.
The study opens new possibilities not only for digital content creation but also for practical design fields that rely on predictive simulations of flexible materials.
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