The phrase "bursting of the hydrogen bubble" itself sounds amusing --- as if one is making a pun on bubble in the literal and in the financial/metaphorical senses of the term. But, then, I might just be too easy to amuse. My thoughts here are about the financial sense and the hydrogen industry as a candidate for major post-fossil-fuels world, energy space. The underlying idea is that hydrogen is the key to storing and transporting energy from the more intermittent renewables. Solar power isn't incoming on cloudy days; wind power isn't helpful when the air is still. But either the sun or the wind can be used to split water into its constituent parts and store the hydrogen side of that split. The stored and transportable gas can then be used for a lot of projects that otherwise would involve the emission of carbon. It can be used for shipping, aviation, the creation of ammonia and methanol, and fuel cells. That's the theory anyway. In practical terms, the ...