Skip to main content

HOW IS HELIUM TURNED INTO A LIQUID AND A SUPERFLUID?

At -269°C, helium gas condenses to become a liquid. Cool it even further and it becomes a state of matter called a superfluid. In this state it has no measurable viscosity and so does some odd things, such as climbing up the walls of a dish, leaking through apparently solid materials and staying motionless while its container is spun. To create the liquid and superfluid states, you cool down helium gas to a few degrees above absolute zero. This is achieved by compressing the gas, and then expelling it through a small nozzle. As the gas expands, it rapidly cools (you’ll have noticed this effect if you’ve ever used an aerosol deodorant). The process is repeated until the gas that rushes out of the nozzle is cold enough to condense to a liquid, then if you repeat the cycle a few more times the helium will become cold enough to turn to a superfluid.

Comments

Popular posts from this blog

DO ALL FISH AND SHELLFISH CONTAIN MERCURY?

Mercury levels in the oceans have tripled since the Industrial Revolution, thanks to mining and the burning of fossil fuels. All sea creatures absorb some of this heavy metal directly, and, once it’s in the body, there’s no way of getting rid of it. The amount of mercury in fish varies between species. Long-lived predators like tuna and swordfish tend to contain the most, because they also absorb mercury from their prey and they’ve had a long time to accumulate it. The lowest levels are found in short-lived species lower down the food chain, such as oysters and shrimp.

Why do different countries use different mains voltages?

Why do different countries use different mains voltages? the biggest disparity is between the usA on 110V and most of the rest of the world on 230V. America’s lower voltage goes all the way back to thomas edison, who introduced direct current (dC) mains electricity at 110V. edison’s rival nikola tesla showed that long power lines transmitted alternating current (AC) more efficiently than dC. His AC approach won out, but he stuck with edison’s 110V. But by the time electrification spread to europe early in the 20th Century, lamps had filaments that could give out more light and handle greater power loads. so the Berliner elektrizitätswerke company in Germany established 230V as the standard. 

The top ten most coldest places in the world.

THE 10 COLDEST PLACES 01 Ridge near Dome Fuji antarctica –93.2°C recorded in August 2010 from a remote sensing satellite. 02 Vostok Station antarctica –89.2°C the lowest groundmonitored temperature, recorded on 21 July 1983 at a russian Antarctic research station. 03 dome Argus antarctica –82.5°C 04 Amundsenscott south pole station antarctica –82.5°C 05 Oymyakon russia –71.2°C the lowest air temperature recorded in the northern hemisphere was detected at this russian village in 1926. 06 Klinck research station greenland –69.4°C 07 north ice greenland –66°C this low was recorded at this British north Greenland expedition research station in 1954. 08 Snag Yukon, Canada –63°C 09 Denali Alaska, USA -59.7°C 10 Verkhoyansk russia –45.4°C