What possible weapons most resembles the lasers used in movies?

[Gagundathar]

@drachillix

Various flavors of projectiles at massive velocities will create visible atmospheric effects. Having sufficient power to drive something to that kind of velocity is the challenge.

Relativistic Baseball

My favorite part of this article is “A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered “hit by pitch”, and would be eligible to advance to first base.”

[Mijin]

@Mijin

While we’re talking about tech that may come off in the near future, in aeronautics, there are a number of teams, including at DARPA, that are using surface plasmas as a means to decrease drag and turbulence.
…
My zero knowledge of ballistics or physics in general, tells me that if you could have a plasma layer ahead of a bullet, it could go faster and/or further, and would leave a flash of light in its wake.

@EdwinAmi

No, but potentially a projectile that’s constantly shooting out air in front of it and around it may reduce the drag of the atmosphere. They do this with torpedos, but that’s to move the water out of the way, which is much denser.

Yeah, but the part where I mentioned that surface plasmas reduce drag, I didn’t make that up.
My lack of physics knowledge or ability is only relevant to extrapolating from that observation.

ETA: sorry, link might be paywalled (New Scientist). Trying to find free one…