All posts tagged: thermodynamics

Physics claims the past and future are identical — so why do we age

Physics claims the past and future are identical — so why do we age

Published by Jenni Sidey

A glass slips from a hand, hits the floor, and bursts into fragments. The sound fades quickly. Heat spreads into the room. Nothing about the scene looks reversible. Yet, in the language of physics, it is. That tension sits at the center of one of the oldest questions in science. The equations that govern motion, energy, relativity, and even quantum behavior do not prefer a direction. Run them forward or backward, they still work. But daily life insists on a different story. Glass breaks but does not rebuild. Coffee cools but never reheats itself. Memory points backward, never forward. You do not wake up younger than you were the night before. Cells wear down. Age accumulates in one direction. No one lives Tuesday, then Monday, then Sunday. In ordinary life, time has a grip. It leaves marks on faces, joints, skin, memory, and muscle. That one-way quality feels so natural that it hardly seems like a mystery until physics says it should not be. Somewhere between clean mathematics and lived experience, time seems to pick …

Einstein claims the past and future are identical – then why do we age

Einstein claims the past and future are identical – then why do we age

Published by Jenni Sidey

A glass slips from your hand, hits the floor, and shatters into pieces. The sound fades quickly. Heat spreads into the room. Nothing about the scene looks reversible. Yet, in the language of physics, it is. That tension sits at the center of one of the oldest questions in science. The equations that govern motion, energy, relativity, and even quantum behavior do not prefer a direction. Run them forward or backward, they still work. But daily life insists on a different story. Glass breaks but does not rebuild. Coffee cools but never reheats itself. Memory points backward, never forward. You do not wake up younger than you were the night before. Cells wear down. Age accumulates in one direction. No one lives Tuesday, then Monday, then Sunday. In ordinary life, time has a grip. It leaves marks on faces, joints, skin, memory, and muscle. That one-way quality feels so natural that it hardly seems like a mystery until physics says it should not be. Somewhere between clean mathematics and lived experience, time seems to pick …

Death is not the end: What physics says about dying

Death is not the end: What physics says about dying

Published by Jenni Sidey

A flame goes out, and something in the room shifts with it. Not because matter has vanished, but because a structure has ended. The candle’s wax remains, the heat disperses, and the air carries what used to be a steady glow. What disappears is the pattern that held it all together. That same tension sits at the center of how physics approaches death. Richard Feynman returned often to a simple statement in his lectures: everything is made of atoms. It sounds basic until you follow the consequences. Atoms obey strict physical laws. They do not vanish. Energy does not disappear. So when a person dies, the idea of complete erasure runs into a problem. Something ends, but not in the way people tend to imagine. Feynman (center) with Robert Oppenheimer (immediately right of Feynman) at a Los Alamos Laboratory social function during the Manhattan Project. (CREDIT: Wikimedia / CC BY-SA 4.0) A body in motion, not a fixed thing Feynman described a human being less like a solid object and more like a process. The …

Backwards heat shows laws of thermodynamics may need a quantum update

Backwards heat shows laws of thermodynamics may need a quantum update

Published by skeptic

Heat normally flows from hot to cold klyaksun/Shutterstock A forgotten cup of coffee will gradually cool down as its heat flows into the cooler surrounding air, but in the quantum realm, it appears this experience can be turned on its head. As a result, we may need to update the second law of thermodynamics, a fundamental principle of physics that states heat energy always flows from hot to cold. Dawei Lu at the Southern University of Science and Technology in China and his colleagues have seemingly broken this law with a molecule of crotonic acid, which contains atoms of carbon, hydrogen and oxygen. The researchers used the nuclei of four of its carbon atoms as qubits, which are the basic building blocks of quantum computers and can store quantum information. When used in computation, researchers normally control the quantum states of the qubits with bursts of electromagnetic radiation, but in this case, the team leveraged this control to make heat flow from a colder, lower-temperature qubit towards a hotter one instead. This would never spontaneously …

We may need a fourth law of thermodynamics for living systems

We may need a fourth law of thermodynamics for living systems

Published by skeptic

A HeLa cell in telophase, a stage at which the chromosomes have separated DR MATTHEW DANIELS/SCIENCE PHOTO LIBRARY The physics of thermodynamics, which involves quantities like heat and entropy, offers well-established tools for determining how far from equilibrium an idealised system of particles is. But when it comes to life, with its complex interconnected cells, it’s not clear that our current array of thermodynamical laws is enough – and a set of experiments involving human cells might be a first step towards creating a new one. Thermodynamics is important for life, because being out of equilibrium is one of its key properties. But because cells are filled with molecules that actively consume energy, a cell’s state is different from, say, a bunch of beads floating in a liquid. For instance, biological cells have what’s called a set point, which means they behave as if they are following an internal thermostat. There is a feedback mechanism that brings them back to the set point, which lets them keep functioning. It is this kind of behaviour that …