This is an alternate version of the previous table-related idea (see link here), which involved hanging a table from the ceiling.
Sometimes, you’re sitting at a table, and the table legs get in the way. So annoying! See Figure 1 to be reminded of this calamity.
Fig. 1: The presence of this table leg is probably stifling your enjoyment of life—if only it weren’t there; then you could sit at the corner of the table.
By putting all of the table legs on a motorized two-dimensional grid on the underside of the table, a computer could automatically detect where a person was sitting and automatically move the table legs out of the way, as shown in Figure 2.
Fig. 2: If the table leg at “A” could be moved from position “A” to position “B” (perhaps by being on a motorized track on the underside of the table), then the individual on the right side of the digram would be able to sit at the corner of the table without the table leg getting in the way.
Unfortunately, there is one downside to this plan; if the table legs are not spaced apart, then the table can easily fall over, as seen in Figure 3.
Fig. 3: A problem: if the table legs slide out of the way, the table will be very easy to tip over; even a small downward force (the red arrow labeled “F”) applied to the X on the table will cause the table to tip over.
The way to solve the tipping problem is quite simple, fortunately; if a force is applied to one corner of the table, we must simply apply an equal (or greater) force to the table leg on the opposite corner, and the table will not fall over. This system is implemented by means of a motorized bowling ball that is controlled by a sliding magnet underneath the table (Figure 4). Alternatively, the weight could be located beneath the table, but that would lack the visual flair of a bowling ball.
Fig. 4: Solution to the table-tipping problem: an extremely heavy weight (here, illustrated as a bowling ball) can roll around on the table and be a counterweight. Now, the table will not tip even if we apply a force point at “F” (shown in step 3), as the weight of the bowling ball prevents the table from tipping over.
PROS: May cause the table-sitter to be crushed beneath the table if the power unexpectedly goes out.
CONS: You may ask, “why not just solve this problem much more simply by putting a single post in the center of the table, and mounting that post on a few horizontal beams and/or a platform?” We leave the refutation of that objection as an exercise to the reader.