What combinations are you thinking of?
Life on earth is based around Carbon chains. Carbon's 4 bonds allows for a low of complex structures that would be hard/impossible for less bonds.
The only other viable option I know of is silicon. Unfortunately its chain equivalent has an extra reaction pathway with water. It would degrade rapidly if exposed to water, which is very common at the energies it would work at.
I'd be curious to look up any other viable options.
The uncanny valley is FAR stronger with moving things Vs inanimate ones. It's likely modified from a revulsion of dead things, but seems to be distinct now.
Most diseases don't show strongly enough to trigger it, most of the time. Historically, the exception has been leprosy. I'm honestly curious if it's evolved to keep us clear of leppers specifically or not.
There are 2 parts at work. The focus reflex and the blink reflex. The window between them is the dangerous part. If the pulse is fast enough ( a few ms) then the eye can't focus, and it's fairly safe (unless you were already focused on the emitter). If the pulse is low enough power then the blink reflex kicks in and protects your eye.
Hitting a mosquito is a hard task, tracking one is even harder. It's better to use an ultra short pulse, with a bit more power. You can also shift the frequency. If it's an infrared laser then the eye won't lock onto it, and will struggle to focus it dangerously.
This idea was tried previously. If done right, it doesn't take much energy to damage a mosquito's wings.
Secondly, a laser is only a real issue for vision if the eye focuses on it. With a continuous beam, it would be instinctive, making it dangerous. If the pulse is short enough however, the eye won't have time to focus and so the power will be safely spread out, even inside the eyeball.
I'd also be fascinated if we figured out a way to do it
I personally suspect it's not common in the animal kingdom. It's quite likely a defense against leprosy, a disease that is most dangerous in larger society type communities, without outside predators (to pick off the sick).
That theory might be wrong however. Its distribution would tell us a lot about what it defends against.
I'm pro suicide. However, a lot of times suicide is a permanent solution to a temporary problem.
There should definitely be at least a couple of doctors in the loop for an assisted suicide. There also needs to be a lot more in the way of support for people in that hole. Both the emotional support, and more practical guidance (it's hard to break out of the cycle when your life is objectively shit and all you can get is "there there, it will get better").
I've taken to telling them that someone else helped me out, and I'm just trying to pay it forward, with interest. If they can pay it forward in future, I would be very happy with them continuing the chain.
You still get the dopamine of a good deed, they feel like they can pay you back by passing it on. If they don't, no harm done. If they do, your good deed just got amplified to some other poor sod's benefit. It might even loop back!
It's quite difficult to retroactively adjust the traffic speed, without causing knock on issues.
A road might have been designed to cope with 50, but hidden junctions, or pedestrians might knock it down to a 30. Making it feel like a 30 is quite different.
I'd personally prefer other, more polite methods. In the UK, the signs showing your current speed in either green (good) or red (too fast) are remarkably effective. I accept that speed cameras are needed when the other methods fail.
Proviso, the cameras should be blatantly obvious, with no ambiguity over the limit. It should only catch people both deliberately speeding, and not paying enough attention to spot the risks of speeding.
https://en.wikipedia.org/wiki/Tachyonic_antitelephone
Basically, an "instant" communication device can create paradoxes.
E.g.
Earth sends mars a instant message. Mars the relay's it via normal radio to a passing ship/probe moving at 0.99C. That probe then sends an "Instant" message to Earth.
The final message will (depending on alignments etc) arrive before the original was sent. If the message the voids the reason for the original message to be sent then a paradox happens.
You can make similar things happen with any form of FTL communication. C isn't technically the speed of light, it is the speed of information. It just happens that light has no other speed limiting, and so moves at maximum speed.
ADHD could have some bearing, if it was something quick and impulsive. Premeditation makes it even more damning however.
Either way, it's not an excuse, just a factor to account for in corpus mentis decisions.
I'm not saying the USA should just disarm its police. I was more pointing out how fucked up gun culture has made it. Most UK gangs don't have guns. The risk reward balance doesn't justify them. Any gang that does try to escalate with guns becomes the focus of a LOT of police attention.
The challenge is, can you figure out where it is.
All hail the lemming of Lemmy!
Silicon's conditions would make it difficult. It has far less inorganic precursor molecules to work from. It might work under cryogenic conditions, but that has a bunch of other problems.
The titanium one is new to me, and potentially interesting. My concern would be an abiogenic pathway. It might be able to form interesting molecules for life, but if they don't appear naturally, then getting life started gets massively more difficult.
There's also a hell of a lot of options with carbon based life. Earth life is VERY locked into a few variants with our base biochemistry. E.g. there's no reason for particular RNA sequences to match particular Protein peptides. Yet it's basically a universal thing. Even chirality is fixed, for no particular reason other than mixing causes issues.
I could potentially see a dual based life system working, effectively a more advanced version of how some creatures use metals to make shells etc, or how horns and hair grow. It could also provide a viable (though extremely convoluted) bootstrap process for titanium life, or something more exotic. Forcing life to change its core functionality however is apparently quite difficult, since no life on earth seems to have done so and survived to be detected. Rocky, in Project Hail Mary, would fall into this group (a carbon life core basically piloting a stone and metal mech).