Throughout my career in chemistry, one of the more interesting debates has been the nature of the cationic exo-2-norbornyl system, and recently (Angew. Chem. Int. Ed. 2014, 53, 5888) a paper was published that included, after a discussion of the original debate, the quote: "To our surprise, the structure of C₇ H₁₁⁺ obtained under our conditions is not that of 2NB+, but instead corresponds to a much more stable rearranged ion." Why was this surprising?
 
First, this is irrelevant to the original debate on the question, why is the rate of solvolysis of the exo-2-norbornyl X systems, where X is a leaving group, proceed much faster than that of the endo system? The isolated 2-norbornyl cation should be the same for each, and is hence irrelevant. The reason for the differences in solvolysis is not the structure of the isolated ion, but rather the activation energy required to reach the transition state, in which the ion is not fully developed. If the ion fully develops as a free ion, then both starting materials will lead to one ion with one energy and structure.
 
Another quote: "Although 2NB+ is well-known in the condensed phase, it is not generally recognized that it is not the C₇ H₁₁+ global energy minimum. Computational studies have explored some C₇ H₁₁+  isomers, but there has been no comprehensive study of the potential energy surface, and no studies of this system at higher levels of theory.[20, 28, 29]". The paper then went on to show from measuring the infrared spectrum of their cations generated in the MS that the ion was the 1,3-cyclopentenyl carbenium ion. This was apparently a surprise to them.
First, the fact that the 1,3-cyclopentenyl ion was at an energy minimum for this system has been known since the 1960s, and the fact that certain cyclohexenyl carbenium ions would contract to a cyclopentenyl system with the methyl generated at an adventitious position was also known in the 1960s. Then, in 1973 I published a paper explaining why such carbenium ion rearrangements take place, and giving a procedure for calculating the energies of the various species. As to why the rearrangement of the norbornyl to the cyclopentenyl system occurs, we might note that the norbornyl system is in effect a five-membered ring with a two-carbon bridge at the 1,3-positions. (Count from C1, and make what is usually C7 now C2.) The system is also highly strained, and forming the cyclopentenyl system relieves that strain. Lose the bridging bond, and the two "methyl" substituents are already in position following the required hydride shifts, which are known to be fast in this system.
To summarize, the fact that the system forms the 1,3-dimethylcyclopentenium cation should not be a surprise. More interesting is the reason this system is in an energy well, not so much for the norbornyl system, where the strain energy makes it somewhat obvious, but rather for the corresponding cyclohexenyl system. The calculations I made do not need "the highest level of quantum computing". What I assumed was that before the ion was formed, the bonds were standard. Now, when the ion is formed, the action in each bond must remain constant, because action is quantized. What does happen to such a standard framework comes from the application of Maxwell's electromagnetic theory. Very specifically, the enhanced electric field polarizes all electric distributions in the space around it If we assign a volume and a relative permittivity to each specific type of bond (in this case C – C and C – H ), then the stabilization depends on the bond's location with respect to the formal charge, which, for a cation, is a carbon atom. An important point was that the assumed permittivities and volumes were consistent with effects noted from electromagnetic radiation. Perhaps not quite as "glamorous" or "sophisticated" as "the highest level of quantum computing", but equally Maxwell's electromagnetic theory is not exactly fringe science either.

One of the most intriguing announcements recently regarding exoplanets is that two planets have been found around the red dwarf Kapteyn's star, which happens to be about rather close to us, at about 13 light years distance. Even more intriguing is its proper motion; it was about 11 light years distant about 11,000 years ago. The reason for this is that it is orbiting the galaxy in the opposite direction to us! Galaxies grow by accreting galaxies, and our galaxy has apparently swallowed a small galaxy, some of which may be known now as the Omega Centauri cluster. Another interesting feature of this star is that it was formed about two billion years after the big bang. Not surprisingly, the star is rather short of heavy elements, as these have to be made in supernovae.
 
The planets have been found using the Doppler method, which measures small variations in velocity of the star as it wobbles due to the planets. This star has a mass of about 0.28 times that of the sun, and a surface temperature of about 3,500 degrees C, and such low stellar masses make the detection of planets somewhat easier, because small stars wobble more through the gravitational effects of the same sized planet. The two planets are (b) at 0.168 A.U. from the star, and at least about 4.5 times Earth's mass, and (c) at 0.311 A.U. from the star, and at least about 7 times Earth's mass. (The "at least" is because what is measured is msini, i.e. the actual tug that we see is the component in our directions, and the angle of the orbital plane is unknown.) The reason this hit the news is that (b) is at a distance from the star where water could be liquid, so it is in the so-called habitable zone. With over 11 billion years for life to evolve, would it? If it would, with an extra 6.5 billion years, why hasn't its technology led to space travel to us?
 
If you accept my theory of planetary formation, the answer is, life there is highly unlikely. In this theory, certain types of planet form at specific temperatures in the accretion disk. The temperature depends on the power generated at a point, which in turn depends on the gravitational potential and the rate of the starwards component of matter flowing through the point. The first, from Newton, is proportional to stellar mass, the second, from observation, is very roughly proportional to stellar mass squared. Accordingly, the radial distance for equal temperatures will vary between accretion disks proportional to stellar mass cubed. Now, this is an extremely rough approximation, not the least because we have left heat radiation out of the calculation and assumed it to be proportionally the same for all disks. However, heat is radiated by dust, which depends on metallicity (which, to astronomers, means elements heavier than helium) and this is an extremely low metallicity star. If we assume my approximate relationship, then the Jupiter equivalent should be at 0.12 A.U. and the Saturn at 0.20 A.U., both plus or minus quite a lot.
 
Notwithstanding the inherent errors, I am reasonably confident we do not have rocky planets there, because while my estimates have a large potential error, there is a huge difference between the melting point of ice and the melting point of iron (needed to get iron lumps as in meteorites). Further, the error is reasonably consistent, being out by a factor of 1.4 for the Jupiter equivalent, and 1.55 for the Saturn equivalent, if those are what they are. That is reasonable for less heat loss due to lower metallicity. In my theory of planetary formation, these two planets would be interpreted as the cores of the Jupiter equivalent (formed like a snowball by ice sticking together near its melting point following collisions) and a Saturn equivalent (formed by melt fusion of methanol/ammonia/water near that eutectic temperature, the energy of the collision providing the heat, the melt then fusing the ice.) The reason they would not develop to full gas giants would be simply a lack of material to grow that big. Of course such dust as was available would also be incorporated, and the resultant planets would be like a giant Ganymede and a giant Titan. Thus I would expect (b) to have little atmosphere but maybe be a waterworld on the face tidally locked to the star, and (c) to have a nitrogen atmosphere, and maybe methane. Why maybe? Because methane is photochemically degraded, and presumably has to be regenerated on Titan. On Kapteyn c, with 11 billion years photochemistry, the methane may not have lasted. There would be no life on (b), nor for that matter in any Europa under-ice ocean, because of a general deficiency of nitrogen, and also a probable difficulty in forming phosphate esters.
 
So, that is my prediction. Unfortunately, I guess I shall never know whether it is right.
 
Finally, a small commercial break! Four of my fictional ebooks are on special at Amazon from the solstice for a few days, including the one that was actually the cause of my developing my alternative theory of planetary formation. The fiction required an unusual discovery on Mars, I invented one, and an editor had the cheek to say it was unbelievable. Now editors in publishing houses have a right to criticize grammar, but not science, so I ended up determined to do something about this. Details of the special are at http://wp.me/p2IwTC-5r

One of the more disturbing pieces of news recently is that the Thwaite glacier is melting, and a lump of ice of area the size of Uruguay and of uncertain thickness will slide off the West Antarctic land mass and fall into the sea over the next couple of hundred years, thus raising the world sea levels by something like 3 - 4 meters. The problem is, it is melting from below, thanks to ocean warming. This, of course, is probably not the only ice sheet under threat, so serious sea level rising must be expected unless we do something to counter it. Before going further, however, it is important to note that the oceans are warming, specifically with an average net power input of 0.64 W/m^2 (Lyman, J. M. and 7 others, 2010. Nature 465:334-337.)
 
That raises the question, what can we do? One thing is very clear: raising carbon taxes or introducing emissions trading certificates is not going to do anything to stop this, although it will presumably raise government revenue, and/or traders' revenues. The fact is, if we stopped burning carbon today, the CO₂ levels would remain at about 400 ppm for a century or so, and the present net heating of the ocean would continue over that time. Since we currently burn about 9 Gt of carbon per year from fossil sources, minor cutbacks simply will not achieve anything of value. Then there is the question of whether any cutbacks are practical. There have been plenty of earnest pledges over the past two decades, but emissions have actually increased.
 
So, what can we try? I do not know. Like many people, I have some rough ideas, but I have no idea whether they would work. In this context, I am reminded of a statement by General Wesley Clark on strategy, which was something like this. There are two sorts of plans: those that won't work and those that might work. You must take one that might work and make it work. The question now is, are there any that might work, or are the changes inevitable? I am optimistic that there are probably plans that might work, but how do we go about considering them?
 
Time to get unpopular! What I have noticed is that we are spending quite large sums of money measuring various emissions. I think much of this work could cease, because we have reached the point where we know more or less what is happening, and further such spending will not make any difference to our future, other than to make us more gloomy. Instead, that money should be redirected towards action that might make our future better.
 
The issue as far as sea level rising is very simple. There are two options only to prevent it. The first is to ensure that the rate of permanent snow deposition is equal to or exceeds the rate of ice melting. If we manage that, sea level stays constant because there is no net inflow of water. In practice, that means generating increased snow deposits in Antarctica and Greenland. The second is to ensure that the oceans receive a net negative power input for some period until balance is restored. Note that neither of these options directly affects carbon emissions. Are either of these options possible? In theory, yes, but in practice, I do not know. They require serious geoengineering. We can come up with plausible physical processes that may or may not work, but even if they do work, the costs and the secondary consequences are unclear. The political problems are enormous, and may be insurmountable because changing climate on this sort of scale will seriously disadvantage some. But failure to do anything will seriously disadvantage all coastal cities, all coastal farms, at least a third of Bangla Desh, and probably everyone from grossly enhanced storms. So, what should we do? Your thoughts, please.