The organic dye used on CD-R and DVD-R has a durability problem because it is susceptible to light. BD-R uses inorganic dye, which is not susceptible to light. Completely different ballgame.

And then again, light is pretty much a non-issue in data centers because the discs will be operating inside sealed servers anyway.

Temperature is actually more important than the energy density in this case. At 650C never mind 900C, you'll still have a lot of trouble with heat--material have an unfortunate tendency to expand and warp (or, worse, snap) at that kind of temperature. Thus, you may be able to turn your car on and off only dozens of times before the SOFC breaks down. This is the real reason why SOFC has never been seriously considered for cars--SOFC has always been relatively compact for the amount of energy they produce (except for the apparatus you'd need to get rid of the huge amounts of heat).

Now, 650C is easy, at least if you are using natural gas as feedstock. (Gasoline may be somewhat more difficult, but not impossible.) Other solid oxide fuel cells that are trying to enter the market operate at or near that temperature range. 350C, though--wow. That will be remarkable, and may indeed be able to brings in an era of fuel cell vehicles, but it'll involve whole new set of chemistry, and I won't believe it until I see it.

you must be a real joy to be around.

I do tend to be a real prick around self-styled net pontiffs who give me unsolicited sermons about having to collecting unemployment checks, yes. Try not doing that sometime. It'll make your own life a lot more enjoyable.

Highly-utilitized systems like the shinkansen are already often running near track capacity, and shorter trains couldn't be run any more frequently in many cases.

The Tokyo-Osaka Shinkansen route is so crowded now that they only allow 16-car trainsets on the tracks. I suspect the only reason they won't make the trainsets even longer is because they don't have the physical room to extend station platforms.

dangerous hackers are out to ruin their lives and their childrens' lives (or something like that).

You sound as if you do not personally believe this, but by exposing passwords to porn sites, LulzSec has done exactly that--ruin people's lives.

Not to cool down the core but to prevent the spent fuel rods from starting up again.

No, the spent rods won't start up again, in the sense of reaching criticality. There's a reason why they're called "spent rods." They do melt down without cooling, however, and that was a big concern because, as you point out, they weren't covered by anything but water.

Coming from Japan, the most frustrating aspect of Acela is that it routinely runs late, due to having to share tracks with those damned freighter trains. The Shinkansen's average delay is measured in seconds; the Japanese routinely plan trips with 5 minute transit time because they can trust the trains to arrive on time.

The main reason Shinkansen trains are fast and on time is because the main routes run on dedicated tracks. On the Yamagata and Akita lines, they do share tracks with local passenger trains, but Shinkansen gets preferred right-of-way.

This, incidentally, is why splitting track and train ownership is a bad idea for high speed rail. Neither side can take full ownership in assuring the most convenience to the end users, which is what generates revenue at the end of the day.