It isn't perfect but think of archery bows and other ancient weapons of war. It depends on the wood.
We are only discussing the level of lossiness the elastic behaviours of these materials are, they are still bad elastic materials, this is why modern composites vastly outperform wooden bows.
Bows are not mechanically primarily worried about energy efficiency, they are worried far more about just how much energy can be stored elastically in it's deformed state than the actual efficiency of energy in vs energy out. This is similar mechanically to a springboard. You can put in much more energy into drawing a bow or depressing a springboard, than you will get out from loosed arrow, or springboarded person.
You mean absorbing less energy. Now there is less to loose.
No I mean it deforms less. It does also end up absorbing less energy, but primarily this happens by the blade acting... less in the entire interaction.
Between all the components of the collision that deform elastically: the ball, the rubber and the blade; the blade is by far the lossiest component when it comes to elastic restitution, becase again, wood is comparitively not a good elastic material. This is why balls bounce better off a steel plate, or hard floor than a blade.
This is why less deformation in the blade is good. Because we want the least amount of interaction from the blade itself. Given the game legality constraints of blade construction, the ideally 'fast' blade approaches the perfectly rigid object (because the rules of blade construction de facto limit it to be a less elastically efficient component than either the ball or the rubber).
A stiffer blade that deforms less, wastes less energy deforming and restituting. Pushing more of the deformation that must inevitably occur with the collision into the rubber and ball, which are both less lossy when deforming and restituting. This is also why common experience also tells us that blades with carbon are stiffer, and therefore also faster. It is possible that the carbon is also a less lossy elastic material, but given that your blade cannot be all ALC, the end result of your blade is still that it is lossier than either the ball or the rubber/sponge.
The point is that the spring board is "tuned" to the divers impact. Why aren't there any 5000 Hz blades?
Again, the springboard acts primarily as an energy storage device. The springboard has better elastic properties than a human body. It deforms more because we want more of the elastic behaviour to occur in the springboard than in the human leg. If you just jump onto an undeformed board once, you would not get any more height than just jumping off a rigid surface of your own power to begin with, otherwise you would have created a perpetual motion machine, as you'd be extracting energy from a passive mechanism.
The point of a springboard is to store energy of multiple collision interactions in it's elastic defomation, and then releasing that energy into a final single impact (even if that is a very long impact).
The blades, as constructed by the rules of table tennis, are not in any significant way energy storage devices. They just waste some of that energy on impact.
In theory, if we ignored the rules of table tennis, it is possible to construct a blade that does store energy over the course of the swing, and if timed correctly can release it at point of impact (like a long bamboo cane).
This is likely to result in a far lower frequency of vibration, as we need something that can deform significantly just from swinging. Eg the frequency of operation of a springboard, is somewhere on the order 0.5Hz (it goes through half a wavelength during your final jump of roughly 1s).
This is clearly not a practical or realistic mode of operation of any actual TT blade.
I am not saying that it is close to an ideal elastic collision quantitatively (eg as opposed to a perfectly inelastic collision).
I'm saying that it is close mechanically. Eg all the energy storage occurs from the impact of 2 kinematic objects. That is to say, we do not have energy stored in the elastic deformation of the objects prior to collision, eg as opposed to jumping of a primed springboard, or loosing an arrow you've drawn.
Yes I know, those precisely support my point. Because the table tennis bat/blade acts precisely NOT at all like a springboard. The faster blade is the stiffer one, eg one that behaves closer to the steel plate, or ideal rigid object.
Co-incidently, stiffer objects, all else being equal, vibrate at a higher frequency. Thus the co-causal relationship between vibrational frequency of the blade and it's 'speed'.
