The problem with high-mass particles is they lose energy when accelerating - and in the physics sense, which includes changing direction, as when traveling around a circular path. Linear accelerators, I assume, do not have such a problem: They don't spin their particles in circular paths. That's my guess anyway, I'm not a physicist.

I remember it ran RISC OS. Looking at pictures of Acorn machines, th A3010 looks like the one I remember - I may be wrong, but not by far. The label on top I remember as quite distinctive.

I found it very useful for media convertions: My IBM had a 2.88MB floppy drive, my other PCs had conventional 1.44MB, and my Atati used some weird Atari thing. The Acorn machine was able to read all of them and so, when not being used for Cannon Fodder (Which I never did manage to finish), it served to exchange data between them.

I remember that program - I had it many many many years ago, on an Acorn for which I can't even recall the model*. I also recall that the PC emulator was painfully, unusably slow - even just entering commands you could see the delay between keypress and character.

* You could run Cannon Fodder on it, and that is what it mostly got used for.

You've not seen enough Made in China electronics. The dirt-cheap approach is to whack a load of LEDs in series with an inductor that acts as a current limiter.

It'd be nice if their latest ridiculously-thin laptop had more than two ports on it, and one of them for headphones.

You get one port, and it's used for charging as well as USB. Want to plug in a USB device? You've got as long as the batteries last.

They succeeded in making an ultra-super-thin laptop - but at the cost of expecting people to fit a USB3 hub in their bag as well.

MIDI has a few surprising applications. Fireworks, for example. Running a firework show is really a matter of setting of lots of igniters with precise timing over the course of an event - and that's exactly the sort of thing MIDI does well. As far as software is concerned, it's just a strange type of music where every note gets played only once.

Inefficient, high-maintenance. Though compact DC motor-generator units were made for one niche application: Generating high voltages for car radios.

You could go smaller. P-orbitals are largely independant: You might be able to get one atom to be part of three diodes at once, with the individual orbitals becoming components. It'd be silly-unstable though, you'd have to keep the thing on helium cooling and try not to whisper too loudly nearby.

One nice thing about DC-DC converters: Switch modes have a really wide input voltage range.9V-30V is not uncommon. The higher the voltage, the less the current they will need.

Efficiency? Yes, especially if you're running of batteries or solar.

There are costs though. Low voltage means more current, which means lots of expensive copper.

With modifications. A lot of things like those motors and LED lighting depends upon inductive current limiting. Give them DC at what seems the right voltage and they'll probably catch fire.

Batteries are intrinsically DC. It's fundamental to how they work.

Designing better inverters is easy. Giving manufacturers a reason to use them is another matter. Very few customers are going to look up the efficiency of their appliance power supply before purchase, so why waste dollars on it?

AC was the only way to send electricity any distance at the time. There were no DC-DC converters back then.

No, tension. While the building as a whole was under compression, parts of the structure were still under tension. The failure points were in the horizontal struts - this can be seen in images of the burning towers in the form of a significant bulging around the impact site. As the struts failed, the structural outer walls bent outwards until eventually reaching the point of failure and collapsing.