3 ms·

For the most part, if you need something a lot lighter than air, Hydrogen works. If you need something inert, there are better and more commonly available noble

For the most part, if you need something a lot lighter than air, Hydrogen works. If you need something inert, there are better and more commonly available noble gases (including neon which is lighter than air, but only slightly). I can't imagine any sort of application where you would need something significantly lighter than air and inert. I'm curious as to which uses actually require helium and only helium.

njarboe 7y ago
A lot of helium use is for machines that need to have parts around 0 Kelvin for superconductivity. It is the only liquid at those temperatures besides Hydrogen and Hydrogen is much more dangerous and reactive.
solotronics 7y ago
sometimes its used as a mix in welding shielding gas (because its inert and lighter than air), typically argon is used but its much heavier than air and certain situations you need to mix with helium
dr_orpheus 7y ago
One of the other reasons helium is used besides being inert and lightweight is its use in cryocooling. That it is why it is used in MRI machines to cool the superconducting magnets. The melting point of helium is 0.95 Kelvin (-458 Farenheit), and is used to cool the superconducting magnets to below 10 K [1]. The other most commonly used liquid for crycooling is liquid nitrogen. But Nitrogen freezes at 63 K (-320 F) so you can not get it cold enough for all applications. Liquid helium is also used in the Aerospace industry for testing or running spacecraft hardware that will be at those extremely cold temperatures. For example the optics of the James Webb Space Telescope need to be that cold in order to measure the weak infrared signals, else the thermal noise from the instrument itself would overwhelm the signal [2] [1] https://www.lindeus.com/en/industries/medical/_mri/liquid_helium.html https://www.lindeus.com/en/industries/medical/_mri/liquid_he... [2] https://jwst.nasa.gov/content/about/faqs/faq.html#temps https://jwst.nasa.gov/content/about/faqs/faq.html#temps
littlestymaar 7y ago
Zeppelins: https://en.m.wikipedia.org/wiki/Hindenburg_disaster https://en.m.wikipedia.org/wiki/Hindenburg_disaster

njarboe 7y ago

A lot of helium use is for machines that need to have parts around 0 Kelvin for superconductivity. It is the only liquid at those temperatures besides Hydrogen and Hydrogen is much more dangerous and reactive.

solotronics 7y ago

sometimes its used as a mix in welding shielding gas (because its inert and lighter than air), typically argon is used but its much heavier than air and certain situations you need to mix with helium

dr_orpheus 7y ago

One of the other reasons helium is used besides being inert and lightweight is its use in cryocooling. That it is why it is used in MRI machines to cool the superconducting magnets. The melting point of helium is 0.95 Kelvin (-458 Farenheit), and is used to cool the superconducting magnets to below 10 K [1]. The other most commonly used liquid for crycooling is liquid nitrogen. But Nitrogen freezes at 63 K (-320 F) so you can not get it cold enough for all applications. Liquid helium is also used in the Aerospace industry for testing or running spacecraft hardware that will be at those extremely cold temperatures. For example the optics of the James Webb Space Telescope need to be that cold in order to measure the weak infrared signals, else the thermal noise from the instrument itself would overwhelm the signal [2] [1] https://www.lindeus.com/en/industries/medical/_mri/liquid_helium.html https://www.lindeus.com/en/industries/medical/_mri/liquid_he... [2] https://jwst.nasa.gov/content/about/faqs/faq.html#temps https://jwst.nasa.gov/content/about/faqs/faq.html#temps

littlestymaar 7y ago

Zeppelins: https://en.m.wikipedia.org/wiki/Hindenburg_disaster https://en.m.wikipedia.org/wiki/Hindenburg_disaster