Where's the propellers?

Yes, it must be a flying machine. It's got, um, propellers.

The second is that the propellers are all pointing in the same direction of the glass, pointing up.

By controlling the speeds of these four propellers, these machines can roll, pitch, yaw, and accelerate along their common orientation.

If we analyze the mathematical model of this machine with only two working propellers, we discover that there's an unconventional way to fly it.

And so here it is in the stomatopod. And again, this is a situation where engineers are very familiar with this phenomenon, because it destroys boat propellers.

Hexacopters and octocopters, with six and eight propellers, can provide redundancy, but quadrocopters are much more popular because they have the minimum number of fixed motor propeller pairs four.

Marine litter related damage to people also includes safety risks at sea (demanding rescue services) owing, inter alia, to fouling of propellers, as well as damage to people's health (injuries, disease) from litter on beaches and in bathing water, including medical waste.

So, as you can see in this prototype, gigantic piano strings, each string is controlled with a little robotic element either little bows that stroke the strings, propellers that tickle the strings, acoustic signals that vibrate the strings. We also have an army of robots on stage.

358. Recommendations in the Guidelines for dealing with the problem, including ways to reduce the chances of taking harmful organisms on board, include informing local agents and or ships of areas and situations where uptake of ballast water should be minimized, such as areas with known populations of harmful pathogens advising ships to avoid loading ballast water in very shallow water or in areas where propellers may stir up sediment and avoiding the unnecessary discharge of ballast.