But according to Richard Feynman and the laws of physics, that intuition is deeply misleading.
At the fundamental level, the equations that describe reality donât care which way time flows. The same mathematics behind Quantum Electrodynamics â the most precisely tested theory in science â work just as well forward in time as they do backward.
In this video, we explore why the past may not be as âgoneâ as it feels.
đ„ *In this video, we explore:* â Why the laws of physics donât distinguish past from future â How particles can be treated as moving backward in time in calculations â What time symmetry really means â and what it doesnât â Why our experience of time is not fundamental â How Feynman explained time without mysticism.
This isnât philosophy or speculation. This is how physicists actually calculate the universe.
Over the past decades, electronics engineers have been trying to develop increasingly smaller devices that can store information reliably, even when they are not powered on. A promising type of non-volatile memory device is spintronics, solid-state systems that store and process information leveraging the spin (i.e., an intrinsic form of angular momentum) of electrons.
Researchers at University of Maryland and other institutes recently introduced a new spintronic device based on nanoscale structures based on materials that exhibit ferromagnetism (i.e., a permanent yet switchable magnetic order) and ferroelectricity (i.e., a permanent yet switchable electric polarization). This device, presented in a paper published in Nature Nanotechnology, can switch between four stable resistance states and could thus serve as a multistate memory.
The system that was nanoengineered by the researchers combines two different types of devices, known as magnetic tunnel junctions (MTJs) and ferroelectric tunnel junctions (FTJs). An MTJ consists of two magnetic thin films separated by an insulating thin film, while an FTJ is composed of two different metal electrode layers separated by a thin ferroelectric film. Both these types of devices have proved to be promising information storage solutions.
For the first time, researchers have demonstrated that the properties of the perovskite family of materials can be used to create so-called quantum bits. The findings, published in the journal Nature Communications, pave the way for more affordable materials in future quantum computers.
According to the researchers from Linköping University, Sweden, behind the study, few within the field believed it would be possible. The reason is that the atoms in perovskite materials should, in theory, interact so strongly that the qubit would collapse before the calculation could be completed. However, the experiments conducted by the Linköping team show that it works.
âOur findings open up an entirely new research field,â says Yuttapoom Puttisong, associate professor at Linköping University.
The LHCb experiment at CERNâs Large Hadron Collider (LHC) has discovered a new particle consisting of two charm quarks and one down quark, a similar structure to the familiar proton, but with two heavy charm quarks replacing the two up quarks of the proton, thus quadrupling its mass. The discovery, presented at the ongoing Moriond conference, will help physicists better understand how the strong force binds protons, neutrons and other composite particles together.
Quarks are fundamental building blocks of matter and come in six flavours: up, down, charm, strange, top and bottom. They usually combine in groups of twos and threes to form mesons and baryons, respectively. Unlike the stable proton, however, most of these mesons and baryons, which are collectively known as hadrons, are unstable and short-lived, making them a challenge to observe. Producing them requires smashing together high-energy particles in a machine such as the Large Hadron Collider (LHC). These unstable hadrons will quickly decay, but the more stable particles that are produced as a result of this decay can be detected and the properties of the original particle can therefore be deduced.
Researchers from Tokyo Metropolitan University have succeeded in detecting laser-assisted electron scattering (LAES) using circularly polarized light for the first time. The use of circularly polarized light promises valuable insights into how atomic scale âhelicityâ impacts how electrons interact with matter and light.
Using synchronized femtosecond laser pulses and electron pulses directed at argon atoms, they succeeded in detecting a LAES signal showing excellent agreement with theory. The findings are published in The Journal of Chemical Physics.
LAES is a cutting-edge tool for understanding how electrons interact with matter under the influence of strong fields. When electrons are fired at atoms or molecules, they are scattered in all directions; the presence of strong light can change the way in which the scattering takes place due to an exchange of energy with the surrounding light field.
Neutrinos are extremely lightweight and electrically neutral particles that rarely interact with ordinary matter. Due to these rare interactions, neutrinos can travel across space almost entirely unaffected, carrying information about highly energetic cosmological events, such as exploding stars or supermassive black holes.
The KM3NeT neutrino telescope, an observatory located at the bottom of the Mediterranean Sea, recently detected the presence of a neutrino carrying extremely high energy, above 100 PeV (peta-electronvolts). This is one of the most energetic neutrinos observed to date.
Theoretical predictions suggested that another large-scale neutrino detector, namely the IceCube detector, would also observe similar high-energy neutrino events. However, this did not happen, which might potentially hint at some new physics, such as a new type of neutrinos or non-standard interactions, that are not included in the standard model of physics.
Does the universe need observers to exist? Neil deGrasse Tyson and co-hosts Chuck Nice and Gary OâReilly explore questions about entropy, spontaneous symmetry breaking, spectroscopy and more with astrophysicist Charles Liu.
Does the universe require observers for information to exist? From Niels Bohr and the Copenhagen interpretation to modern neuroscience and philosophy, the crew explores whether measurement creates reality or reveals it. How does the double-slit experiment fit into this? Are wave and particle behaviors determined by how we measure them?
The conversation turns to information itself. What do physicists mean by âinformationâ? How is entropy connected to hidden information in a system? We discuss entropy through everyday examples like coin flips, burning wood, and boiling water. How does this relate to quantum computing? We explore how astronomers separate cosmic redshift from stellar motion using spectroscopy, how interstellar dust and extinction curves complicate observations, and why mapping that dust is both a challenge and a source of discovery.
We discuss why the Big Bang didnât form a black hole, how spontaneous symmetry breaking may have split the fundamental forces, and whether science can meaningfully investigate the universeâs earliest moments. Wrapping up, the team looks ahead to multi-messenger astronomy, next-generation telescope technology, exotic ideas about the speed of light, and how information continues to reshape what we know about the cosmos.
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One solution to the Eco, âElephant in the Roomâ- of space launches.
Everything burns. Given the right environment, all matter can burn by adding oxygen, but finding the right mix and generating enough heat makes some materials combust more easily than others. Researchers interested in knowing more about a type of fire called discrete burning used ESAâs microgravity experiment facilities to investigate.
In a series of parabolic flights and on sounding rockets launched from Sweden, a team from Professor Jeffrey Bergthorson at McGill University in Canada and Eindhoven University of Technology in The Netherlands investigated burning iron powder in zero gravity. Their research was pure physics, the scientists wanted to know more about discrete burning whereby flames do not burn through fuel continuously but jump from one fuel source to another. This form of fire hardly occurs naturally on Earth, but an example is a forest fire where one tree burns completely and the fire jumps to the next tree when the temperature increases enough for combustion.
Burning iron dust in experiments on zero-g aircraft and rocket flights allowed for the iron particles to float and ignite discreetly. High-speed cameras captured the spectacle and allowed the researchers to better understand the phenomenon, resulting in computer models that showed the ideal conditions to burn the fuel on Earth.
A new AI framework called THOR is transforming how scientists calculate the behavior of atoms inside materials. Instead of relying on slow simulations that take weeks of supercomputer time, the system uses tensor network mathematics and machine-learning models to solve the problem directly. The approach can compute key thermodynamic properties hundreds of times faster while preserving accuracy. Researchers say this could accelerate discoveries in materials science, physics, and chemistry.
