John Cuthber

A couple of high power IR lasers would be a better bet than "magic chemicals".

And there's the overhead of sending data to and from the computer.

I presume he garbled this https://mechasco.wordpress.com/2014/05/23/billiard-balls-and-the-90-degree-rule/

Really. Playing pool must be interesting in your world.

That's an interesting interpretation of taking 100,000 years of historical data and extrapolating 100 years into the future. (And , of course, by "interesting" I mean wrong)

No, they are not. Invar is slightly denser than iron. Bronze is a bit denser than tin, but not as dense as copper- much as you would expect. You can make an argument for lead having a rather low density. It's about as dense as silver, but the atoms in it are about as heavy as those in gold, so they must be spaced out more widely. If they are spaced out more, they aren't densely packed. Back at the topic... If you have some alloy which absorbs hydrogen then that absorption is going to be accompanied by a release of energy. You have to remove that energy as heat when you "refill the tank". Even if the absorption energy is only 1% of the combustion energy that's a lot of heat. Say you want a tank which holds as much energy as the petrol tank in a typical car. That's about 50 litres. Petrol stores about 35MJ/L So the full tank holds 1.8GJ If you "waste" 1% of that as lost heat then you have 18MJ to remove. Filling the tank in 5 min gives you 300 seconds over which to lose the energy. That's about 60KW you have to dissipate in order to store the hydrogen when you fill up. Have fun.

It's impossible to tell. The Pool's pH is 8 so it is slightly alkaline. But we can't know if that is because it contains a small amount of a strong alkali, or a larger amount of a weak alkali. The best way to get some sort of answer is to take a sample of the pool water- say 1 litre and add small known volumes of the acid and measure the Ph change with each addition until you get to the pH you want. (It may be easier to measure the volume of a diluted acid.) Then you can scale up the amount of acid you need for the volume of the whole pool. I'd start by only adding half that much to the pool- to see what happens. You can add the rest if it turns out not to be enough. But it's very hard to remove it if you overdo it. Having said that, it's quite possible that adding the acid will have practically no effect on the pH. The cement in many pools will dissolve slightly and make the water alkaline. Adding acid will just make more cement dissolve.

Is there a problem with the simple precipitation of the material by mixing solutions of sodium borate and nickel sulphate?

If you don't understand this, you should ask... How do they reach the insects? What stops them reaching the plants? It's clear enough that I'm talking about the pheromones. And I asked how the pheromones reach the insects (and the answer is through the air). And I also asked what stops the pheromones getting to the plants and the answer is obviously nothing. The pheromones will reach the plants. So, since in the real world, the pheromones reach the plants, it isn't sensible to say You may think I'm a bit blunt; even rude. Perhaps I am, but did it not occur to you that it's also rude to post misleading nonsense like that?

Yes, we now know that we can't really do it. That's what happens AFTER the pheromones reach teh bugs. I asked how the get there. The answer is by diffusion through the air. You have completely ignored my other question. I guess you realised it makes you look stupid.

How do they reach the insects? What stops them reaching the plants? You clearly have no idea what you are talking about. That article refers to a laboratory scale sample of a few grams of soil. OK, so the biggest supercritical fluid extractors treat about a ton at a time. So, for a field 100 meters on each side and half a metre deep you would need 5000 extractions. Perhaps you would like to calculate the cost (in energy and solvent) of doing that? It's certainly not "A Practical Solution For Every Any Problem"

And many common drugs are improved versions of natural products (because the originals were not good enough) The same is true of many foods, It's almost as if some natural things- like senility and death are not all that wonderful.

Yeah. And so are (most of ) the most toxic things we know. e.g. http://theconversation.com/the-five-most-poisonous-substances-from-polonium-to-mercury-29619 https://io9.gizmodo.com/5861680/10-of-the-most-dangerous-chemicals-in-the-world etc

Fusion at low pressures (well below atmospheric) is perfectly possible. The trick is to ensure that the particles are moving fast and they are contained for a relatively long time. https://en.wikipedia.org/wiki/Fusor It's also important to recognise that stars like the Sun do a very slow job of fusion. They take billions of years to do it. On a weight for weigh basis, I emit more heat than the Sun.

On this planet, it is exactly impossible. Not only is the production of sufficient food for humanity without the use of further pesticides impossible, there is no way to remove the pesticides that are already widespread in the environment- DDT is probably the best known example. Please take the trouble to find out what you are talking about , before telling everyone that I'm wrong. Incidentally, how did you come to the conclusion that pheromones are harmless to humans?

A foot thick layer of silicone will be expensive.

https://en.wikipedia.org/wiki/Fumed_silica

If you are running a nuclear reactor then you can just wait for random "spontaneous fission" where the nucleus falls apart without being hit by anything. If you are making a nuclear bomb, then you don't have long enough to wait. They rely on neutron sources based on things like mixtures of radium (which emits alpha particles) and Beryllium (which emits neutrons when hit by alpha particles. And, if you want to make sure there are neutrons... https://en.wikipedia.org/wiki/Startup_neutron_source

It depends how far you are from the guns too. But sound level isn't what makes bombs scary. It's irrelevant I have heard terrorist bomb. I work on a site that tests explosives. I know what the bangs sound like. Stop banging on about it in this patronising manner.

That's impossible

Fair point, but the OP's post is impossible.

Nature never "chose" anything. I have never heard of any serious experiment which tried to create life. There have been many where people tried (and succeeded) to make molecules that might have formed early life. We have never even created a bacterium. Suggesting we could make a human (except by the traditional method: man + woman + 9 months ) is absurd.

There is a huge difference between the massive damage caused by CO2 from use of petroleum as fuel and the (admittedly not-trivial) damage caused by their use in plastics etc.

Lead forms two different chlorides. PbCl2 https://en.wikipedia.org/wiki/Lead(II)_chloride and PbCl4 https://en.wikipedia.org/wiki/Lead_tetrachloride depending on whether it loses 2 electrons or 4 There are other, similar compounds (the Pb(IV) compounds are generally less stable)

And you can keep doing it for as long as it takes you to count to three. Do you really not understand that "the status quo" should be the overwhelmingly likely outcome? If you are going to use statistics, make sure you do it right.