This also seems a convenient bit of propaganda, of course they would say that to scare the Russians.
If it's true, it's a really cool feat of engineering though! Can't wait for the fog of war to lift and see what cool civilian applications all this drone tech will have.
I have some better quality kitchen knives I like keeping sharp.
I use a two-sided whetstone 400/2000 grit for basic shaping (400 is akin to those rolling sharpeners, to be used only when you fucked up real bad), a leather strop with green sharpening paste (~6000-8000 grit) glued to a piece of wood, a plain leather strop, and a honing steel.
Green sharpening paste is most of what I ever use, a couple of strokes weekly (more realistically about 20 once a month), and maybe polish it up with the plain leather strop. Keeps the knives wicked sharp, and then I just hone them after each use.
Sometimes I do stupid things and get burrs in my edge (like cleaving frozen bone), that's where the 2000 grit saves me.
400 I guess is for when the apocalypse comes or your kids decided to practice chef's knife throwing into scrap metal. It's nice to know I can remake a whole edge, but rarely used.
Unfortunately, Russia decided early on that international law and relations are an acceptable price for their war. That means some bad stuff will come their way as well, and very little sympathy will be heard from the rest of the world.
My list is quite different than the ones currently in the thread.
The boring ones:
Creating a vaccine or other cloaking to make humans invisible to ticks & mosquitoes. A separate project would be to do the same for parasites.
Enacting strict pollution/carbon limits and mandatory circular economy everywhere in the world.
Researching, trialing and Enacting a sustainable post-capitalist system everywhere in the world.
Developing solar energy until covering global energy demands, including a power network that can transport energy from the sunny side and/or orbit everywhere.
The slightly more ambitious:
Establish self-sustainable colonies living on off-earth resources, most probably also situated off-earth.
Create a Dyson swarm with enough energy output for in-system exploration, mining, colonisation, and terraforming.
Perfect matter replicators.
I have some other ideas as well, but those would be a start.
Heat is electromagnetic radiation - photons, sound is mechanical displacement - phonons.
They mostly propagate the same due to being waves, in most other respects they are very different.
Heat convection is an entirely separate process where heat radiation is aided by the movement of the surrounding medium. Where it would otherwise heat up it's environment, convection keeps the environment from heating up. Compare coffee in a thermos (very little convection) to a cup you're blowing on (significant convection); more air movement - more cooling.
Also, destructive interference does not at all work like that.
Maybe a more useful analogy could be that waves have like walking animations, where in part of the animation they go up, and in another part they go down. Destructive interference happens when a wave in its' "up" phase crosses a wave in it's "down", meaning the resulting movement looks like nothing. The waves don't however interact in any way, and will continue on their way and on their own animation cycles.
The shifting and heating parts are technically true but require very specific circumstances, enough so that I'm more prone to believe it's another misunderstanding of the physics behind this. But I'll give you the benefit of the doubt.
Good reasons to omit details include brevity, legibility, pedagogy and scope.
Showing the supporting evidence for all steps in an evidence chain is simply not feasible, and we commonly have to accept that a certain presupposed level of knowledge as well as ambiguity is necessary. And much of the challenge is to be precise enough in the things that need precision.
You're right to be sceptical until more data is presented, but saying no claim of progress is ever true is quite obviously a gross misrepresentation of our current reality. You are doing this on digital devices interconnected with millions of users ar staggering speed and latency. Every part of which are scientific claims.