One of my bugbears is the constant implication in the popular press that the twin problems of anthropogenic global warming and peak oil will be solved by the mythical “hydrogen economy.”
Take this article in The Guardian newspaper:
The main fuels used in history form a nearly exact sequence, from ones having 
less hydrogen to ones having more. Wood and charcoal were the earliest fuels, and have only a little hydrogen. Much of their burning is wasted in pouring out great gusts of carbon, which was needed to build up the tree from which the wood came, but doesn’t do much for the user burning that wood.
Coal has more hydrogen, and its burning can be cleaner. Oil – which dominated next – has yet more hydrogen per unit of carbon; natural gas has even more, and its burning is the cleanest and most efficient of them all. The trend line points pretty strongly to a pure hydrogen economy – but when that will occur is in the hands not of the scientists, but our wise political masters.
Hydrogen fuel cells have some promise as an energy storage medium, but you still need a source of energy in the first place: much of the commercial hydrogen produced today is actually produced from natural gas in a process which still produces carbon dioxide emissions.
Alternative methods using biological extraction have proven successful – but they still don’t tackle the 
fundamental problem of where the energy to extract the hydrogen comes from. With oil running out and our current industrial infrastructure reliant on dumping stored carbon dioxide into the atmosphere this is the problem that needs to be solved.
And if the basic problem is getting energy, wouldn’t it be better to concentrate on that and, once this problem is solved, use this source of hydrogen-producing energy to produce petroleum via the Fischer-Tropsch process and save £X trillions by avoiding upgrading our entire transport infrastructure to use hydrogen tanks and fuel cells?
My conclusion: every penny of research currently being poured into the hydrogen economy should be diverted into developing cleaner nuclear fission and synthetic petroleum fuel combined with hybrid electric-petrol vehicles.
Monday rant over.
[main article from The Guardian][other articles from PhysOrg][images from felixmolter and gavindjharper]
desalination. These membranes will some day be able to replace conventional membranes and greatly reduce energy use for desalination.
Space scientists have come up with a novel way of studying the moon (and possibly later other satellites like Europa).