Feb 2024
Bits of rock may point to the oldest known midair asteroid disintegration
An asteroid may have exploded over Antarctica about 2.5 million years ago
Sep 2019
Structures called Mach disks show up in both types of plumes
CO2 from champagne bottles can form shock waves like those seen in rocket exhaust
Aug 2020
Scientists have now mapped the structure of the unusual spinning blaze
Four types of flames join forces to make this eerie ‘blue whirl’
Mar 2021
Cold plasma is squirrely, but researchers found a new way to hold it in place for a bit
A magnetic trap captures elusive ultracold plasma
Nov 2019
A mix of rigidity and flexibility in the movement of atoms can cause collapse
Molecular jiggling may explain why some solids shrink when heated
Oct 2020
The device picks up sound waves made by hot objects
A new thermometer measures temperature with sound
Jun 2020
Bose-Einstein condensates in space could reach temperatures lower than any known in the universe
This weird quantum state of matter was made in orbit for the first time
Aug 2021
A National Ignition Facility experiment produced a record 1.3 million joules of fusion energy
With a powerful laser blast, scientists near a nuclear fusion milestone
Oct 2018
In the journal Science (September 2018), researchers reported a method for making a coating that reflects sunlight and radiates heat. The coating can be used to cool buildings and reduce air-conditioning use, keeping surfaces painted with the material about 6 degrees Celsius cooler than the surrounding air temperature. The paint can be easily applied to most surfaces, including the exterior walls and roofs of existing buildings. The cooling effect is based on a phenomenon known as passive daytime radiative cooling, whereby a surface cools without any energy input by reflecting ultraviolet to near-infrared solar radiation (278- to 4600-nanometer wavelengths) and radiating long-wave radiation (8000- to 13,000-nanometer wavelengths) through the atmosphere to outer space. Cool roofs designed using metals (such as aluminum) or white-pigmented paints help keep building temperatures lower by reflecting sunlight but are less effective at emitting the heat they absorb because heat is reflected inside these materials. See also: Buildings; Emissivity; Heat transfer; Infrared radiation; Paint and coatings; Radiation; Reflection of electromagnetic radiation; Solar radiation
Cooling paint
Feb 2019
Progress continues in the attempt to master nuclear fusion—the phenomenon that powers the stars, including our Sun—for energy production here on Earth. Recent research has identified a previously unknown kind of heat burst that causes reaction-killing instabilities inside experimental fusion machines, called tokamaks. These doughnut-shaped vessels contain and sustain the controlled fusion reaction, using magnetic fields to trap and guide superheated hydrogen. On Earth, nuclear fusion requires heating hydrogen up to approximately 100 million Kelvin (100 million degrees Celsius or 180 million degrees Fahrenheit), thus converting it into a state of matter called plasma. Within this superheated plasma, atoms can start to fuse together into heavier atoms, releasing energy in the process. See also: Atom; Atomic nucleus; Atomic physics; Earth; Electricity; Energy; Energy sources; Gas; Hydrogen; Magnetic confinement fusion; Matter (physics); Nuclear fusion; Nuclear physics; Nuclear reaction; Plasma (physics); Star; Sun; Temperature; Thermonuclear reaction
Harnessing the power of nuclear fusion in tokamak reactors