Thursday, February 4th 2021, 10:27 am - The laws of physics get a little off-kilter once the temperature drops low enough.
Though temperatures may rise and fall as the season wears on, Canada is still very much a cold-weather country, and eventually extreme cold sets in in one corner or another.
But aside from the usual woes of having to live well below zero, here are four weird extreme cold effects that look like they belong in science fiction.
1. SOUND CARRIES FOREVER
When you live in Yukon, you expect a few frigid February mornings, but what happened on February 3rd, 1947, was uncharted territory.
That day, the small outpost of Snag saw temperatures bottom out at about -63°C, the coldest ever recorded in mainland North America, and never matched since.
Living through Canada’s coldest day made minor celebrities of the meteorologists who recorded that new low, and based on media write-ups and later interviews, it sounds like they experienced some really weird side-effects. The most notable: Sound suddenly carried VERY far.
As some examples: One meteorologist reported being able to hear dogs barking in the village of Snag, some five kilometres away. An approaching airplane was first heard approaching more than 30 km away, and when it was directly overhead the airport, at an altitude of 10,000 feet, it sounded like it was landing right beside it. Ice cracking on a river more than a kilometre away sounded like distant gunfire.
Like everything else that looks like science fiction, this one is easily explicable by science.
THE SOUNDS OF SNOW: LISTEN TO THE DIFFERENCE BETWEEN MINUS 5 AND MINUS 15
That fateful day, the Snag area would have experienced a ‘temperature inversion’ -- what happens when a layer of very cold air has sunk down to ground level, leaving the layer above it actually warmer and less dense. Sound waves, from any source, tend to bend away from less dense air toward colder, denser air -- essentially arcing back down to ground level, travelling further and thus being more audible.
Listen for yourself the next time your part of Canada gets very cold, though don’t expect it to be as extreme as in Snag, where we imagine someone talking smack about their colleagues a kilometre away from the airport while on a stroll would have returned to a few dagger glares.
2. ANIMALS (AND, MAYBE, HUMANS) ENTER SUSPENDED ANIMATION
As we’ve written about before, the average human body has an internal temperature sweet spot of around 37°C, and it does NOT like it when that figure wobbles more than a couple of degrees in either direction. Almost all mammals have a body chemistry that’s similarly finicky.
Amphibians are another story. They famously can't self-regulate their body temperatures, so have to rely on their environment to warm themselves up when they need to.
Alternatively, there’s the North America wood frog, which just embraces the inevitable and allows itself to freeze solid, as in the video below:
We should clarify: They don’t freeze COMPLETELY solid, which is the key to understanding how some species not only can survive the ordeal, it’s a normal part of their lives.
As the U.S. National Science Foundation explains, once the temperature falls to around zero and the freezing process begins, the frog survives by producing “a type of antifreeze made with glucose, keeping the water in their cells in a liquid state at temperatures below [0 degrees Celsius].”
And the suspended animation is near total: The frog’s heart stops beating, its kidneys shut down and it no longer breathes. It can survive in this state for months, and when temperatures return to more comfortable levels, it can thaw its way back to life in about 10 hours.
It’s a pretty neat trick for a species whose sprawling habitat stretches even up to the Arctic, but humans definitely shouldn’t try that at home, right?
Well, sure, until quite recently, the idea of humans entering suspended animation was firmly in the realm of actual science fiction. In fact, mild hypothermia starts setting in around the 32-35°C, worsening the colder the victim gets and becoming fatal eventually.
However, late in 2019, scientists at the University of Maryland announced some promising, if terrifying, news: They’d successfully put a human being in suspended animation for the first time, as part of an ongoing trial on ER patients.
Why do we say ‘terrifying?’ That’s due to the fact the trial involves ER patients who have suffered such devastating injuries that their heart has stopped due to blood loss, according to the study’s very stringent criteria. The scientists’ method, according to the New Scientist, involves replacing all the patients’ blood with a very cold saline solution, lowering the patient’s temperature to the 10-15°C range. That hopefully buys surgeons up to two hours to repair the damage before warming the patient up and starting their heart, without serious brain damage.
That study is still ongoing (the lead scientists wants to announce results by the end of 2020), but still a harrowing thing to think about.
3. JUST ABOUT EVERYTHING SHATTERS
Freezing things (and people) with liquid nitrogen is an old sci-fi stalwart, from Terminator to Demolition Man to James Bond.
Far from a niche method of dispatching supervillains, however, it’s a completely plausible scientific process which doubles as a really fun YouTube rabbit hole to vanish into.
We’ll start with why liquid nitrogen is the lightning-quick cooling tool: Unlike water, remains a liquid below 100°C and above 0°C, nitrogen, which makes up almost four-fifths of Earth’s atmosphere, only liquifies at -210°C. Not only does that make it cold enough to rapidly cool something, its liquid state allows it to completely envelop an object submerged in it, spreading the extreme cold evenly.
As it happens, just about anything submerged in liquid nitrogen can be cooled to the point that it will shatter, like this rose in the video below:
In the case of organic material, it’s easy enough to explain: The water in cells freezes solid, making it easy to shatter like ice.
But what about inorganic material that doesn’t have any water-laden cells? That’s where you get down to the atomic level.
At higher temperatures, the atoms within a structure are more mobile, allowing it to distribute the stress of, say, a hammer blow more evenly (and also easier to bend). Cool it down, and atomic motion slows down, making them more rigid, and much easier to snap, or even shatter.
For a Canadian example, remember that winter tires are made of a different kind of rubber than all-seasons, to make it less rigid and better able to “grip” the road in extreme cold. For other, more fun examples, we turn again to YouTube. Here’s someone obliterating a heavy-duty padlock:
Incidentally, flash-freezing and shattering your enemies T-1000-style requires more than just splashing them with liquid nitrogen. Because a person’s skin is much warmer than liquid nitrogen, brief contact will heat the nitrogen up back up to a gaseous state fast enough to not cause any serious damage.
(Please don’t try this on your own).