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Oh sure, you say that now, you gorgeous bastard! Then we let you move in, you force us to clean chicken without bleach, make us give up our cookies for biscuits, and before you know it we're all sleeping together on the wrong side of the road! OTOH, if we get British television series standards, I vote LEAVE. It's the rare US show I like, while it's rare for me to find a British show I don't like. You seem to look for actors who can act rather than actors with no physical flaws, and your writers write the way people talk.

Just look around Google. Here are a couple of stills 700 × 394

Currantly

...and many more find that creating the illusion of it instead...is better for the bottom line

"Phi for All" is starting to make way more sense to me as a forum moniker. In the presence of such stunning punning virtuosity, it could cause my art to choke! Is it time to plantain other topic?

If electricity is more expensive than natural gas, what is the economic incentive of moving to hydrogen, even at a 20% mix? Hydrogen isn't going to be cheaper than the electricity that generates it. How is your electricity generated?

Hmm. I am more interested in what we can actually do, here and now, given the infrastructure we have inherited, than in revisiting what we might or might not have done differently years ago. Climate change can't wait for perfect solutions. And in my opinion (not being a man of the left) I think it would be a mistake to expect governments to pick winners. I think it is better for them to encourage different technologies, allow them to compete and over time we will see which ones turn out to have the most scope for optimisation. What I mean by optimisation, in this context, is not merely what is technically best, but all the things in society that enable a solution to gain traction. Then again, we may find it is better to diversify and use more than one route than to put all our eggs in one basket. Other contributors have spoken of hydrogen being "hyped". I must say I am not aware of any noticeable hype around hydrogen. Almost everything I read seems to be about the electric car issue. Not many people are talking about HGVs and those that are starting to talk in the media about domestic heating seem preoccupied with heat pumps, even those these cost 5 times as much as a gas boiler and put out heat at only 50C max, instead of the 65C for which most central heating system are designed. So there are huge issues to overcome to make heat pumps realistic for most householders. On a personal note, I have been thinking of getting a heat pump for my large Victorian house. This will cost me a bit, and will never pay back, given that electricity costs 3-4 times as much as gas, per kWh. However I do draw the line at ripping up all the floorboards as well, to install the underfloor heating pipes required to make the low-grade heat from the pump sufficient to warm the house. Millions of others will face this issue. This is one of the reasons why I can see the logic in converting the gas network to hydrogen, either fully or at 20% dose rate as a medium term measure.

It's good that you asked in Linear Algebra And Group Theory, because we're going to need some algebra you likely have never seen (unless you went to college) to answer it. Multiplication isn't one thing. What multiplication is depends on what you're multiplying. Algebra is how we define this. In Algebra, there are a handful of different kinds of structures. Here, we're interested in Groups, Rings, and Fields. Rings and Fields are kind of made of Groups, so we'll start there. Say we have a set (the lay concept of set will work fine for our purposes), and we'll call it S. On this set, we need to define a rule called a "binary relation" that takes any two things in the set and gives some output. We want this set to be closed under this relation, so the relation can only give us things that are already in the set. For this combination of set and relation (for now, we'll use ? to denote the relation) to be a Group, they need to have the following properties: 1) Associativity: for any three things a, b, and c in the set, the relation doesn't care about where the parentheses go. a?(b?c)=(a?b)?c 2) Identity: there is a special thing in the set (traditionally denoted by e when talking abstractly) where, for any other thing a in the set, a?e=e?a=a 3) Invertability: for any thing a in the set, there is another thing in the set a* where a?a*=e=a* That's enough to be a Group. But we want a special kind of Group, called an Abelian Group. That's just a regular Group that has an extra property: 4) Commutativity: for any two things a and b in the set, a?b=b?a Tradition dictates that for Abelian Groups, + is used in place of ? and 0 is used in place of e and -a in place of a*. If a Group is not Abelian, we often use × (or nothing at all) in place of ? and 1 in place of e and 1/a in place of a*. If S is the set, we write (S, +) or (S, ×) for the group, but we often just write S if it is clear from the context that we're talking about a group. This is enough to let us build a Ring. With Rings, we still have a set S, but we have two relations. (S, +) is an Abelian Group, but × is a bit more lax. × only has to satisfy two properties: 1) Identity, and 2) Distributivity: for any three things a, b, and c in S, a×(b+c)=(a×b)+(a×c) Like how (S, ?) is a Group, (S, +, ×) is a Ring. If a Ring is commutative and has inverses for each relation, then the Ring is called a Field. There are four particularly important facts mentioned above that are important to why a negative times a negative is a positive: 1) a+(-a)=0, 2) a+0=a, 3) a×0=0 (not mentioned above, but still important), and 4) a×(b+c)=(a×b)+(a×c) Proof -a×-b = a×b: Let a and b be positive numbers in our field (S, +, ×). 0=b+(-b)=a(b+(-b)) -a×-b = (-a×-b) + a(b+(-b)) = -a×-b + a×b + a×-b = -a×-b + a×-b + a×b = -b×a + -b×-a +a×b = -b(a+(-a)) + a×b = a×b TL;DR: It's because Fields are commutative, have identities, and are distributive

Also it seems to me that OP sees SF in a very narrow context. The genre has almost always been more a commentary on society and its development rather than the application of science to a literary genres. In fact, more often than not, the "science" part is just the vehicle to make a point (similar to the purpose of, say, monsters in fantasy). There are of course notable exceptions where the science part is heavy and sometimes is considered under the genre of "hard" SF. As a whole it is but a small slice of the overall SF picture. As such one could expand the question to ask whether fiction or even literature is bad for society.

I don't think this is an imaginary numbers problem. If the square root of x is minus one, then x = 1 is a solution. Root (1) = -1