High-energy ion collisions have produced the swirliest fluid ever discovered, in a state of matter that mimics the early universe.
To create the überwhirly liquid, scientists slammed gold ions together at velocities approaching the speed of light at Brookhaven National Laboratory in Upton, N.Y. Such collisions, performed in Brookhaven’s Relativistic Heavy Ion Collider, cook up an ultrahot fluid, re-creating the state of the universe millionths of a second after the Big Bang, before protons and neutrons had formed. In this fluid, known as a quark-gluon plasma, the constituents of protons and neutrons — quarks and gluons — intermingle freely (SN: 12/10/16, p. 9).
Scientists already knew that this fluid is the hottest ever produced in a laboratory, and that it has almost no viscosity. Now, physicists can add one more unusual property to the list. The quark-gluon plasma created in such collisions has an average vorticity — or swirliness — of about 9 billion trillion radians per second, researchers from the STAR Collaboration report online January 23 at arXiv.org. That’s vastly more than other known fluids. Even the core of a supercell tornado has a vorticity of only 0.1 radians per second.
上海花千坊爱上海
To measure vorticity, the scientists studied a quantum mechanical property called spin from particles produced in the collision known as lambda baryons. The spin, an intrinsic type of angular momentum, tends to align with the vorticity of the fluid, providing a window into the plasma’s gyrations.
相关文章Exclusive: Hong Kong mutual benefit policy serves to complement rather than compete with potential partners: HKSAR Chief Executive
Editors Note: Hong Kong Special Administrative Region (HKSAR) Chief Executive, John Lee Ka-chiu (Lee), led a high-level delegation of 70 people to participate in the third Belt and Road Forum for International Cooperation held in Beijing from October 18 to 19. At the forum, he invited entrepreneurs to Hong Kong to set up belt and […]
Growing fondness: why are Arab youth increasingly drawn to China?A recent public opinion survey conducted in Dubai targeting Arab youth revealed that eight out of 10 respondents consider China an ally, marking the highest number of respondents to hold this view in four years. According to data from the United Nations Population Fund, the Arab region is characterized by a substantial youth population, with […]
China’s medical assistance boosts healthcare development in South Pacific region"For this surgery, we have prepared for more than half a year," Xiao Yuehai told the Global Times when talking about the first laparoscopic surgery carried out in Solomon Islands. Xiao is an urologist from the Affiliated Hospital of Guizhou Medical University (AHGMU) and a member of the second group of Chinese medical workers dispatched […]
Shake down under
还没有评论,来说两句吧...