Shpaget

Lasers can ablate and/or fuse material that is already, they can't deposit new material. Different materials have different absorption properties for different wavelengths so there could be instances where you can use a laser that penetrates surface material and does some work on sublayer made of some other material. For example, electronic traces on smartphone display (while powered on, to boot): https://www.youtube.com/watch?v=ks-lS11TIaY On certain partially opaque materials you can set the laser up so the focus is inside the material and reaches the energy density to do the work, but on shallower layers energy density is not high enough to do it. An example are those tacky acrylic 3d engravings. https://www.youtube.com/watch?v=_wDRXUzfZAw Another way is to hit a specific spot from multiple sides to combine the effect. Radiation therapy for cancer is an example of this, although not with laser but with ionizing radiation. Those are fiber lasers and are 100% real. I've got one in my basement. I haven't really tested it on rust and regular paint (stuff you would find on cars or railings), but it can easily remove some thin paint (maybe its powder coating, maybe it some film type thing) from aluminium business cards I have. It can mark the anodization on aluminium, engrave and cut steel, aluminium and brass. I tried to find something rusty to test just for you, but apparently I keep all my iron stuff well oiled.

For almost ten years I've been hoping he'll keep his word and return, and once in a blue moon I would check, just in case he did. For ten years no joy. Well, today I checked again, and he's back! Zogg from Betelgeuse is back!

Not today, but a few days ago, I got my hands on a brand new fiber laser! A 60W MOPA thingy. It can cut through 0,4 mm alu and steel plate with ease, and even 1 mm brass sheet (took a bit longer). pew pew

Your wish may come true, according to a new study. We may be mere decades from the fireworks, not centuries. https://arxiv.org/pdf/2306.00287.pdf

Metal doesn't need to reach melting temperature to weld. https://en.wikipedia.org/wiki/Cold_welding While this effect is primarily a concern in vacuum, and requires clean surfaces, I don't thing it's too big of a stretch to imagine that such a violent collision would evacuate most of the air at the point of impact, and possibly expose new, clean, material to contact.

Do you really think that a bit of metal tubing is a significant factor in the total cost of modern missiles? Come on dude, a ten second google search will tell you that they cost hundreds of thousands of dollars for even the smallest ones. As for inflatable shells, I would imagine that you'd like your missiles to be capable of steering without folding, and accelerating at a decent rate without collapsing on themselves.

Haven't seen the movie, but the trailer is chock-full of bad stuff. "I've got a shadow moving across the front of the Moon, and it's not Earth." Too bad it was not Earth, it would have saved the studio some embarrassment., but speaking of shadows, that looks like a terminator, not a shadow of another object. "This object is roughly the size of a city." Yet the shadow easily covers entire Moon That shuttle like vehicle takes off without the main engines firing. but keeps all four boosters and the external tank all the way up to the "meteor". They are hit by a giant rock, but deploying a repair bot will fix it, I suppose. Shooting guns at asteroids? If Armageddon and Deep Impact had a baby, and then abused it, neglected it and beat t with a stupid stick.

Factories at 9000 m? I can't imagine that being sensible. Not only you need to haul all the stuff up and down, but so many industrial processes depend on atmosphere, so even if you could provide oxygen for personnel, the machines themselves need air too, so you'll need to pressurize the factories, which is certainly not trivial. But why do it anyway. Not even Japan, the stereotypically crowded country is in such a short supply of space to need this.

To be fair, cruise ships have a whole bunch of stuff dedicated to unnecessary luxury, while a generational ship would probably lack all the casinos and shopping malls and as a whole look a lot more like the crew quarters of the cruise ships than the passenger areas.

If an approximation, even a darn good one, was a satisfactory answer, there are simpler solutions and we wouldn't even be having this discussion. The point is that it's impossible to get the exact value.

Squaring a circle is problem of constructing a square with the area of a given circle using only a compass and a straight edge. What you said is a bunch of words that form almost, but not quite, gramatially correct sentences, yet lack in any coherence and meaning, while introducing concepts that have absolutely nothing to do with squares, circles, areas, straight edges or compass (most of which you fail to mention at all).

ITERs tokamak is quite a bit larger which is quite a factor when it comes to pressure vessels.

Can you elaborate?

It's that time of the year again, when the serious try to compete against the whimsical. Loved and hated for the exact same reasons, not bound by the confines of its own name, the one and only - Eurovision Song Contest. Any favourites?

And again, why would you collect oxygen?

Vacuum would have no effect on motion, other than no drag so higher speeds would be possible, but if you are thinking about free fall (floating in zero gravity), then there would be no translation. In the video, the motor is placed on the surface of a table and the wire is pushing against it. Since there is some torque between the wire and the battery, and the rotation of the wire is constrained, only the battery rotates which leads to rolling. In free fall there would be no such constraint and the wire would rotate freely in the opposite direction of the battery, and since there would be nothing to roll against there would be no translation.

SRBs are chemical rockets. Their high thrust comes from a whole lot of fuel burning very fast. That is not the same thing as energy density, or efficiency (ISP).

I may be having a deja-vu, but I believe it has been said on a few occasions that chemical propellants such as LH are more energy dense than high explosives. Given that we can't even remotely send a 500 ton rocket to orbit using only 50 tons of best fuel we have, it should go without saying that we can't do it with an order of a magnitude less energetic fuel either. Why not ask your friendly neighbourhood alien for their grandma's fuel recipe?

It makes zero sense to collect air/oxygen. You still need to accelerate all of it, but now need to carry all the mass of scoop, compressors and chillers, plus all the extra drag of the scoop. If you need it, take it from home. Also why sphere?

I thought it was the deer hunters.

What collected air / lox?

This would finally be viable. Which should tell you everything you need to know about "legality" of your idea.

That effect is due to rolling shutter of CMOS camera sensors. In KSP, pretty much every time I tried to stage with the booster still firing, it ended exactly like this flight. What is supposed to provide acceleration for Starship to pull away from the booster? The flip? Or were they planning on firing the second stage while still attached?

In that case, a "Not even close to scale" disclaimer would have been quite appropriate.

Don't know about the small smooth massively upscaled ball, but the high resolution one with the straight lines is Europa.