It's only $30 if she's already running Leopard (10.5). If she's on Tiger (10.4), it's no longer considered an upgrade and will cost $170.

The UK stand alone in world with its absurd ban on driving lessons on motorways.

No, it has Ireland for company (as in so many things). Or it did when I was learning to drive, anyway.

Also, a real second-declension neuter noun in Latin would use a singular verb, even when it is plural. So applying Latin-like rules to English, "data is" is still correct.

Now the iPod is like Kleenex or Hoover - the generic name for all players.

Not yet with people I talk to (in the Washington DC metro area). For them iPod is still very specifically an Apple device. I hear "MP3 player" much more often when people aren't actually talking about the Apple product.

Only a very small sample, obviously.

Yes, but there's more to violence than guns. Rocks, baseball bats, fists, boots ...

(and a small percentage of 7-year-olds do seem to be able to get at their parents' guns)

... and, um, violence?

Just wanted to point out that the pulsar timing array approach will cover a completely different frequency range (~ 10^-9 to 10^-7 Hz) to existing ground-based detectors (LIGO, Virgo and friends), which operate in the 10^1 to 10^4 Hz range. In between are projects like LISA (http://lisa.jpl.nasa.gov/).

The different frequency ranges mean different astrophysical sources of gravitational waves; generally speaking, the more massive the system, the lower the GW frequency. LISA, for instance, would see the radiation produced by the supermassive black holes at the centres of galaxies, while the other detectors would be targetting much smaller systems.

I disagree, unless "segway" means anything apart from the Jeff Bezos creation.

"Segue" is pronounced "segway", and is almost certainly what the product name was evoking.

... unless the boy as doing the smiting.

I dunno ... perhaps you should check out one of their competitors' ads to find out.

At what speed do they need to spin in order for them not to collapse?

All current research seems to indicate that eventually -all- orbiting BHs will merge eventually, regardless of spin. When the holes are large and aligned with the orbital angular momentum, it will -delay- merger: the system has to radiate more angular momentum before it can collapse.

One of the first numerical relativity papers to demonstrate this effect can be found here: http://xxx.lanl.gov/abs/gr-qc/0604012

Can I assume that the difference between the mass of the product hole and the sum of the masses of the two predecessor holes is released as energy?

Yes; the mass difference is radiated as gravitational waves.

Also, a wilder question: when the two event horizons come into contact, is it possible for a "bubble" to form for a short time between them which is cut off from the rest of space-time by the two event horizons, but is not technically within either - sort of a Chandrasekharian Kaliningrad?

I'm not absolutely sure, but I haven't seen results from any simulation that hasn't maintained a "simply connected" (i.e. no strange disconnected regions) common horizon.

Well for one thing, the "time moving slowly" thing is an observer-dependent effect. If you were the one falling into the hole, you wouldn't notice any real time lag at all [depending on the size of the hole -- and your personal oxygen supply, etc -- you might even survive crossing the horizon].

But to a distant observer, your progress would look more and more gradual. Signals leaving you would also get more and more red-shifted, and eventually pass out of the visible spectrum. So a distant observer would never see you cross the horizon.

What happens when two black holes actually intersect at their event horizons? Inquiring non-astrophysicists would like to know.

They merge into one bigger hole. The final hole mass will be (almost) the sum of the two masses, and will likely have a significant spin, even if the pre-merger holes don't.

Disclaimer: this is actually my area of research.