Havatra

Unsure why you’re getting downvoted (this is “No Stupid Questions”, after all), but I’ll give my 5 cents:

Reason 1:
The people is essentially the reason why a government has power. Without the people (and their support), the government governs a whole lot of nothing, and they will be forced to do labour themselves.

Reason 2:
Poisoning the water is not very accurate, and may lead to both the death of many whom already are supportive of the government (which will create distrust), and people only getting sick depending on the amount they drink (the dose makes the poison).

Reason 3:
Despite a population having a lot of dissidents, these people still work and contribute to society in some ways. It has to get pretty bad before it will be “worth it” to remove them from society.

Reason 4:
Even if it’s so bad that you’re looking at an open revolt against the government, poisoning the water will only really yield MAD, which is usually undesirable.

Ultimately, it’s unlikely desirable for any government to do this, as there are better ways (for the government). However, there have been some attempts at genocide through water supplies before, so it’s not completely unheard of. Check out Project Coast.

Depends on the conditions, I’d say. If you have an area that has low oxygen and high saline concentration, one could potentially preserve large parts of the carcass. A big challenge though is the substances brought by the carcass itself, like enzymes and bacteria that are not directly exposed to the oxygen-deficient saline-abundant water, which can thrive and remain active for a long period of time. However, if this carcass sinks to incredible depths, where the pressure is really high, temperature is a constant 4 degrees, very low concentration of scavengers or thriving organisms, and potentially sinks a bit into the sediment for a long time, you’ll essentially get pickle juice fossil fuel.

They only recently made it mandatory for three visa types, but since introduced in October 2016, it’s always been an optional field when applying for an ESTA.

Edit:
Not that not providing your social media handle will benefit you, of course.

As biber@feddit.org pointed out, this 1000-fold increase is compared to barium titanate by itself, not to standard silicium solutions. However, it’s still worth pointing out:

Panels made with this technology could be much more efficient and require less space than current silicon-based solar cells,
(…)
The material is also simpler to manufacture and more durable, as it does not require special packaging.