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LNG is pretty fascinating technology. A real product of our times. Have you ever seen the inside of an LNG tanker pressure vessel? Allow me to show you! https:
by blamazon 4y ago
LNG is pretty fascinating technology. A real product of our times. Have you ever seen the inside of an LNG tanker pressure vessel? Allow me to show you!
https://upload.wikimedia.org/wikipedia/commons/e/e6/Liquid_natural_gas_membrane_tank.jpg https://upload.wikimedia.org/wikipedia/commons/e/e6/Liquid_n...
I don't know why they're waffle pattern yet but it sure looks cool. One day I want to stand inside one.
- ahartmetz 4y agoI assume that the waffle pattern allows thermal contraction and expansion without "crinkling" or worse.
- blamazon 4y agoWeb search says you're right - negative 162 Celsius / 260 fahrenheit! Wow! About twice as cold as the coldest natural place on earth apparently.
- eesmith 4y agoI think you are calculating as "twice the distance from 0 C", which is a relatively arbitrary zero point. Change the zero point and the ratios change. The coldest measured temperature is -89.2 C, so -162 C is indeed about twice that C value. However, in Kelvin that's 184 K for Vostok and 111 K for LNG, which is only 40% colder.
- philliphaydon 4y agoHow many people use kelvin to quantify temperature.
- wtcactus 4y agoI think the point is that -2C is not twice as cold as -1C, that would imply that -1C was infinitely more cold than 0C. An analogy is the same as seen with percentages. It's wrong to say, for instance, that 2% growth, it's double of 1% growth.
- mercutio2 4y agoEveryone who cares about precision or thermodynamics? I was about to make the same comment: the freezing point of water is a really odd choice to make up a ratio for. If you have to do it, you’d almost always use Kelvin, or in a pinch the equilibrium temperature of a big greenhouse 1 AU from the sun, i.e. 20C.
- philliphaydon 4y ago> Everyone who cares about precision or thermodynamics? So like 3 people... My point is talking about Kelvin is meaningless to the vast majority of people on HN, including myself. Everyone (Except the US) knows Celsius, and it's easy to gague how cold something is looking at it in Celsius. In Kelvin its just 'ok that's a number...'
- layer8 4y agoYou’re underestimating the HN crowd. I’d expect everyone halfway scientifically literate to have an understanding of the Kelvin scale. It’s also quite an intuitive scale, physically, especially if you’re coming from Celsius.
- revertmean 4y agoI think you're wrong. I suspect most people on HN have an above average interest in physics and would therefore have a reasonable understanding of the Kelvin temperature scale.
- Denvercoder9 4y ago> So like 3 people... Just about everything human-built around you had someone consider the thermodynamics of it during the design.
- mrep 4y agoI learned kelvin in high school chemistry and I'm not sure why you wouldn't use kelvin when talking about liquids that far negative in celsius/fahrenheit and that close to absolute zero.
- eesmith 4y agoThat's rather tangential to my point, which is the phrase "twice as cold" as used here is tricky to interpret. What does "twice as cold" mean? In the US, is -2°F twice as cold as -1°F? Yet that's only -18.33°F to -18.89°F, so only 0.3% colder if you change temperature scale. Is 16°F twice as cold as 32°F? Or half as warm? Is -10C infinitely colder than 0C? I used Kelvin as an example of how the ratio depends on the scale chosen, not because it's popular. Note that Rankin (Rankin is to Fahrenheit as Kelvin is to Celsius) would give the same answer as Kelvin - both Rankin and Kelvin are absolute scales of temperature, and would better candidates for defining what "twice as cold" means. (Though even better would be to say "half has hot".) However, I was not saying that we should all use Kelvin, only that the phrase is tricky to interpret.
- _Microft 4y agoDon't downvote that - it's correct: the Celsius scale is an "interval scale" while the Kelvin scale is a "ratio scale". One must not take ratios of Celsius values as ratios are not even defined for that. https://en.wikipedia.org/wiki/Level_of_measurement https://en.wikipedia.org/wiki/Level_of_measurement
- blamazon 4y agoSo, "about" twice as much then? ;) This whole thread is very funny this morning, I was posting at 3AM and not thinking much. I am happy to be corrected, the more I learn to know here the more I learn I don't know or can't immediately recall. I damn this fickle lump of head thinkmeat, but praise the enlightened hive mind of internet commenters!
- antipotoad 4y agoI can’t help but be reminded by your comment of this classic: https://www.youtube.com/watch?v=7tScAyNaRdQ https://www.youtube.com/watch?v=7tScAyNaRdQ
- Ferrotin 4y agoIt is very reasonable to describe coldness as a distance from some reference temperature, such as room temperature.
- tgv 4y agoWhat's so interesting and current about it? Cars drove on LNG (propane) 50 years ago.
- blamazon 4y agoOh, you are right, I should be more specific, I intend to refer to the practice of bulk transport of atmospheric pressure LNG at globalized scale.
- mannykannot 4y agoPropane is much easier to use than LNG (which is mostly methane) as it remains liquid at ordinary outdoor temperatures with relatively moderate pressure.
- mercutio2 4y agoPropane is a completely different molecule from LNG which is mostly methane. Methane is not liquid at normal surface temperatures even at high pressure; propane is.
- lazide 4y agoPropane is a refined, and somewhat synthesized molecule. LNG is rather raw, and contains a lot of free hydrogen, methane, and sometimes other contaminants like sulphur (though that is mostly lower grades). Think of the difference between 91 octane gas at a pump vs slightly filtered crude oil.