If by Nordics you mean Norway, Sweden and Finland, then the most correct way to say would be that ground source heat pumps for redidential heating are (very) common in Sweden and Finland, especially in newer and larger buildings. Norway is somewhat different in energy and climate perspective than its eastern neighbours.
The biggest reason to not install ground source heat pump is high installation cost. This means that it makes more sense for larger residential buildings. Also If you have district heating available then this might be more economical in the long run.
They are widely sold at 1000 mg (1g) tablets in Europe, but in many countries they require doctor's prescription. There are also purchase limits to the number of pills you can buy at once.
Yes, ground transport (except long distance trucks) can be electrified now. In principle, most homes could be heated with electricity if we had means to store all the "excess" wind energy or waste heat from e.g. datacenters and use it in district heating. The technology for heat storage is mostly ready but the capacity is not.
But would it be easy or obvious what to do next? Absolutely not. Everything is simple if you have pockets full of money, live in temperate climates and do not rely on energy intensive (and hard to electrify) industries like the Nordic countries.
For example, about 25 per cent of the total energy consumption in Finland is used to heat buildings. Wood burning is about half of the total heating in distric heating systems which account about half of the total heating for buildings. Also heat-storing fireplaces are still a small but a crucial part of the total picture. A lot of extra energy capacity is needed just make sure you stay alive during the coldest months even if some of the systems fail.
Nordic countries have cheap electricity mostly for two reasons: very stable interconnected electric grid and lots of different renewable energy sources. Arguably, hydropower is the most important because it can stabilize the intermittent wind power which in many places we have more than enough already. Nuclear energy is also a major part of electricity production in Sweden and Finland.
And yet our electric grid or electricity production capacity is far from ready to handle even the more realistic dreams of "full electrification" we are told in the media. It will take many years just to get the grid ready.
And what happens if the stablest renewable, hydropower, fails? We might find it out this year as hydropower reserves in Norway are at the lowest level in 20 years. Hydro generates about 90% of Norway's total electricity.
And also replicated with participants not used to high temperatures inside a typical Finnish sauna. As the study said such people are very difficult to find in Finland. But I wonder if a person who has never been to a real sauna would tolerate this study protocol (2*15 min at 73° Celsius) without any training.
Sauna and hot climates may sound counterintuitive, but it has been tested by most Finns that when you come out of a hot sauna any outside temperature feels cool.
Modern heat pumps can heat efficiently at -25 degrees Celsius or even lower. Not sure if they are available in Canada, but in Scandinavia (similar climate) they are pretty common.
I also agree that 66F (about 19 degrees Celsius) is not comfortable during day time. It is fine for sleeping temperature. During winter homes in heating dominated climates typically have higher indoor temperatures. One advantage of lower inside temperature is that relative humidity stays slightly higher when it is very cold outside.
Stearates are considered very safe chemical compounds. They are derived from stearic acid which is one of the most common fatty acids and metal ions such as sodium and magnesium. Sodium stearate is a common soap and magnesium stearate is one of the most common additives in pharmaceuticals. This means that they are practically everywhere and but also easily digested in small amounts.
You are right that such device does not exist, but in theory you could combine many analytical techniques to a single black box that could analyze practically all of molecules and particles in the air or even in more complicated samples. It would contain at least some sort of chromatography, nmr, mass spectrometer, infrared spectrometer and various special analytical techniques for some compounds. Also some kind of sample preparation system would be needed.
This would be a very large machine and you would need to provide a sample to it in a test tube or similar manner. Automated blood analyzers in hospitals are maybe the closest thing to a such device.
The biggest reason to not install ground source heat pump is high installation cost. This means that it makes more sense for larger residential buildings. Also If you have district heating available then this might be more economical in the long run.