max kingsbury

Undetectable? No way. If the signal is being transmitted through space, it can be observed by a third party. Same goes for untraceable.

They might be difficult to pinpoint, because they use very tight, focused beams. This would make them more discrete than using RF, as RF waves propagate in all directions.

read the article.

it states that it would work with a custom application that would operate with the interface drawn on the silicone. "would" being the operative word.

Wouldn't work. Unless you glued the silicone to the screen of the phone, the capacitive touch sensing wouldn't function. Try putting a piece of clear plastic over your iPhone and using it.

This is one reason that these "concepts" are a waste of time.

Glass is a great dielectric for the capacitive sensing that all modern touchpads use. If you understood the technology itself and not just the shiny bits, you might know that.

It could just be continuously writing to the SD card, and simply marking the unneeded footage as "blank" when the 5 seconds runs out. This would require extra free space on the card, and potentially pose a security risk.

Why 2 remotes?

Some devices get smaller, some don't. The performance desktop computer hasn't shrunk much in the last decade. Devices that keep the same features tend to get smaller, while those whose features expand stay the same size. This receiver doesn't just receive, it generates video for the xross, it upsamples video. It does all kinds of things that receivers didn't used to do.

I see two real possibilities: This card stabilizes constant voltages on the bus, or it keeps electromagnetic waves from flying out into other cards.

1: The card bus should provide two voltage "rails" to power devices on the bus. These rails are DC, one at a positive value and one at 0(ground.) These rails are used to power the devices. Power flows from the high one, through some load, to the low one. Imagine a store of water at the top of a contraption, a water wheel in the middle, and another store of water in the bottom.
When current is consumed from the rails, the voltages of the rails have a tendency to "dip." Imagine the upper store of water coming down slightly when tons of water is let out. When the rails dip, bad things can happen. Probably nothing you need to worry about, but it is a measurable phenomenon.
Capacitors store energy as unit charges(electrons, pieces of current) on two parallel plates at different voltages. Capacitors resist changes in voltage by dumping charge. Thus, a capacitor between ground and your positive voltage rail can reduce fluctuations in the rail voltage.

2: Current flowing through a wire creates electromagnetic radiation. Electromagnetic radiation can then float around in space, and cause current flow in another wire. This can be bad. If you have very fast transitions between no current and some current, you can expect more electromagnetic radiation, and more induced current elsewhere.
Ground planes(big pieces of conducting material attached to ground) can absorb electromagnetic radiation so that it does not penetrate to the wires on the other side. This is what Faraday cages do.

tl;dr version: It may not actually do anything useful, but it probably does do "something."

I'm not sure why this is called a "robot" and not a "legged RC vehicle."

meh