I was inspired today by this little robot’s ability to change direction very rapidly.

This works by conservation of angular momentum of the whole system (car+tail). As the tail whips around in one direction, the body spins in the opposite direction to meet it.

Having low friction feet means that the robot can make these turns with very small frictional losses.

All this set me thinking about today’s invention: a car with a tail.

Such a vehicle would carry some mass at the end of a hinged cantilever tail (this might be where the fuel was stored).

The hinge would be powered by a fast-response electric motor.

Using four fat conventional tyres would result in significant damage to them on every tight turn, so it might be necesssary to equip the vehicle with more, computer-steerable wheels (including perhaps under the tail itself).

The accelerations induced would still of course need to be less than would cause damage to the occupants, but in principle such a vehicle could make very rapid changes of direction (perhaps useful for a military vehicle attempting to evade incoming missiles).

This form of transport could be made more comfortable by having seats which rotated in coordination with changes in direction, but more gradually, keeping the occupants’ backs against the seatbacks.

Today’s invention is a toothbrush which fires water (red) at one’s teeth whilst brushing, but which also then sucks the debris (blue) out of the mouth and down the sink.

The suction would operate just as the tube they force into your mouth at the dentist’s does -except that this would be much less invasive and uncomfortable.

The supply pressure at the tap would be used to drive water through a nozzle in the brush head, greatly accelerating the flow.

The dirty water extraction could be powered by the normal vibration motor in the handle, which would also drive a small peristaltic pump.

I was caught in deep snow, on a hill, this evening. My 2-wheel drive vehicle went so far up and no further. I wanted to push it to the kerb but was scared that any momentum would cause it to career backwards into various parked cars/ lamposts/ trees.

Today’s invention is an attempt to help people push their vehicles with more control than can be achieved when standing with the driver’s door open, ankle deep in flakes.

It takes the form of a remote control for the vehicle’s brakes.

Ideally this would operate the main brakes in a gradual way (rather than the binary states offered by the handbrake).

This could be incorporated into one’s key fob and activated only when the engine was off.

As you rock the car back and forth to nudge it backwards, the brakes could be eased off and on from outside, allowing the car to make small, controllable progress.

This system might also come with a adjustable lock for the steering which could be set before moving the car a little and then reset, iterating slowly towards a target position.

Ball bearings have always fascinated me, since manufacturing them still has an element of artistry about it. Roll a large number of them about long enough between parallel grinding plates and they come out statistically spherical and smooth within controllable tolerances.

If however you want to know how far from perfect a given ball is (perhaps for a very high performance application), today’s invention may help.

When a perfect conducting sphere is subject to a very high voltage it will, theoretically, distribute charge uniformly across its surface. Regions with locally sharper radius will concentrate charge.

Imagine a machine, therefore, in which each candidate sphere is charged up on a non-conducting plate in a dry-air enclosure, using a very high-voltage source.

Approach the sphere with a micrometer-driven conducting wand. Record the proximity at which discharge by air breakdown occurs. Sharper regions will discharge at greater distances from the wand.

This can be repeated for a large number of different rotational positions to ensure that each ball is spherical to within ultra-fine limits.

(The wand might contain a tiny reservoir of ink, so that the sharpest point on each ball might be highlighted by attracting a dot of oppositely-charged pigment).