To my knowledge, the fastest man-made object of that size was a manhole cover, and it only reached 66 km/s instead of 3,000: https://en.m.wikipedia.org/wiki/Operation_Plumbbob

https://en.wikipedia.org/wiki/Breakthrough_Starshot

A semi-serious project. Using solar sails. Each probe supposedly contains a computer chip. And weighs less than 10 grams.

The plan is to launch lots of them, but if each individual one weighs < 10 grams, does that count?

@DonaldHobson oof, yeah those wouldn't count but that's exactly the kind of thing I'd be curious about. Alas, I set my threshold too high. Maybe they'll make a bigger one!

Must have a method for propulsion

Is not elaborate enough, what does it mean? Can you provide a counterexample, where the object resolved the market positively, but had no methods for propulsion?

@KongoLandwalker I'll have to think on this, but roughly something like a railgun projectile, an object with a solar sail, etc., where another object is providing the thrust

@Stralor so, railgun and solar sail are NOT adequate for this question? Like they are passive perceptors of the interaction

@KongoLandwalker no, they are! how should I phrase it?

@Stralor what if some nucleus, created in the thermonuclear explosion (Fe for example), reaches the speed?

Which reference frame is this in? The Earth's? The Sun's? The Milky Way's?

@TheAllMemeingEye I suppose it has to be Earth's, no? Or is any choice negligible?

@Stralor Earth is ok. If humanity goes the black-hole path to resolve this market, then the object will likely be destroyed and we would not be able to extract the info from it's locally installed clock, we would only be able to to an approximation.

Adjusted the criteria. Do these seem adequate for now?

@Stralor what if we discover a black hole in the solar system, send a probe into it, and parts of probe are converted into jets of matter beamed out of the solar system at relativistic velocities? Does the 10 gram threshold hold in this case for the total matter converted and ejected from the black hole?

@RemNi wow great hypothetical! I'd like to hear thoughts from other traders. Anybody?

@Stralor Personally I think it would be more useful for us to bet on intact objects due to the ambiguity of whether at all and for how long pieces count as the same object. Like, would ejecta from a rocket engine count? Would Bomb shrapnel count? etc.

@TheAllMemeingEye reasonable!

If we're excluding things that can technically be human-made but not human-invented (e.g. helium), then would artificial elements (e.g. Oganesson) or molecules (e.g. a carbon buckyball) be the smallest thing that counts?

If your intention was spaceships, then maybe being self-propelled should be a requirement (so nothing inside an accelerator)?

@TheAllMemeingEye I'm happy with self-propelled. I'll add that thanks

@Stralor hmm but it misses out on stuff like ground-to-space lasers pushing objects. maybe it's not a perfect fit

@Stralor how about self- or externally-propelled? So the acceleration has to happen outside of the device, excluding projectiles launched from particle accelerators but including solar/laser sails

@TheAllMemeingEye Yeah I added a line in the criteria. Do you think that works?

Helium can be human-made out of 4 protons (2 protons will decay into neutrons and electrons and something else). I think that is the easiest way to resolve YES.

Maybe set a minimum mass for the object, instead of saying that accelerated particles are not "human made" ?

@RemNi I guess this is the route I must go

Why don't particles in an accelerator count, if the proton comes from a chair or something? It would be a piece of something human-built.

@Mira proton as a thing existed before the chair. When I make a chair out of wood, and then disassemble it, i cannot say I made the piece of wood.

One of the smallest things that can be actually made (assembled in artificial process) is helium.

@Mira but the real answer is because I'm more interested in us sending objects flying