Fastest in atmosphere object?

>>9105723
Probably meteorites.

>>9105734
so something like 20 to 40 km/s?

>>9105723
Probably that manhole cover during that underground nuke test. Some of the more generous estimates put it at escape velocity.

>>9105784
Scratch that, the lower bound for the steel plate cap is 66 km/s based on the single frame it appeared in on the high speed camera.

>>9105784
assuming it wasn't ablated away on launch

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>>9105930
>>9105797

Speaking of nukes launching disks of metal real fast. Have these ever been tested or are they entirely theoretical? I've read estimates that they could accelerate a tungsten disk to over 2000 km/s

>>9105942

In space, sure.

Not in atmo. They'll vaporize.

The limit in atmo is something like 40-50 km/s before it turns to plasma.

>>9106184
So it would create a relativistic spear of plasma inside atmosphere? Would it leave a vacuum in its wake?

>>9106194
66 km/s is nowhere near relativistic

>>9106194

It'd be similar to a plasma railgun shot of similar energy input in appearance.

Yes, it'd have a huge wake of flame, flash and plasma moving at very high speeds through the atmo. It'd be like a massive plasma torch for a second.

In space, you'll have a far more linear slug, though it'll probably still be plasma compared to say a traditional EFP or superplastic shaped charge.

>>9106209
I'm talking about a casaba howitzer not that manhole cover.

>>9105797
everytime I'm reminded of this my brain just can't even

>>9105942
Shaped nuclear charges have been tested but nothing resembling an actual Orion Drive pulse unit or Casaba Howitzer is known to have ever been set off. They did do testing with bomb pumped X-ray lasers in the 80s though if I recall correctly.

>>9106390
Any documentation/papers on those tests?

>>9105942
If you could accelerate something like that, would there be any practical way to use it as a weapon? Transcontinental artillery?

>>9105784
>>9105797
>>9105930
link?

>>9107429
I dunno about in atmosphere, but in space it would be capable of thick armor penetration at extreme distances.

>>9107499
https://en.m.wikipedia.org/wiki/Operation_Plumbbob

See the section about the steel plate cap

>>9105942
>>9106184
>>9107429
>>9107639

This weapon doesn't fire a disk of tungsten, it produces a jet of tungsten plasma. That plasma blasts through everything in its path.

Imagine a HEAT round, except it has a yield of 500 kilotons. No bunker could survive that.

Why would I bother with a death laser when I can accelerate tungsten towards light speed? Its not like your fat ass is going to dodge it.

>>9107429
Kinetic bombardment https://en.m.wikipedia.org/wiki/Kinetic_bombardment

>>9107956
I came

>>9105723
>triple digit mach
>33,000-330,000 m/s
>>9105784
yeah, that was the pascal b nuclear test. The manhole cover is predicted to have reached reached at least 66000 m/s, mach 200

>>9108748
so did this plate instantly disintegrate? Would you have been able to see a flash or something from the metal turning into plasma and dispersing?

Photons and then maybe lightning

>>9105750
Solar escape velocity is 11km/s, so for two orbital objects you're getting 22km/s at best.

Anything higher is extrasolar and justifiably rare as fuck.

>>9108887
iirc their high speed cameras picked up a single frame of the steel plate. That's all they got. They can only extrapolate either by calculation of energies involved in the detonation or by the time of detonation and the single frame recording of the plate to guess at what really happened.

So /sci/, how did a nuclear blast accelerate that steel plate to (minimum) 30 km/s that one time if the pressure wave of the bomb was limited to travelling at the speed of sound? Or is the entire theory behind why a light gas gun can achieve a higher muzzle velocity bogus?

>>9108887

It would have gone to plasma and eventually ablated into nothing

>>9109375

There's more to a nuke than the shock wave. The thermal radiation is c, for example. The speed of the bomb casing being turned into radiation would be moving very, very fast.

The projectile would be turned to plasma, and it'd be accelerated to very high velocities as the pressure put on it inside the device, is far higher than the typical shock wave.

>>9109382
>eventually

At 30km/s minimum, it would have spent a maximum of three seconds in the atmosphere, and most of that time would be in the upper atmosphere where the density is very low.

30 km/s is just the lower bound, it could have been going much faster, which means less time to heat up and ablate. There's a range of speeds where a steel plate will be destroyed by ablation going straight up, and at some point going faster means less damage is caused. Eventually another region is entered where the speed is so high that the air simply blows the steel apart and causes it to instantly explode as all the tiny particles of metal stop and super-heat all at once.

The question is, did the plate's velocity fall between these two destructive regions or not?

>>9109247
>Solar escape velocity
can be more than 11 km/s
https://en.wikipedia.org/wiki/Escape_velocity#List_of_escape_velocities

>>9109399

I'm going to say it was vaporized before getting out of the atmosphere at those speeds.

Mild steel, poor shape, and not much mass of steel.

>>9109375
>if the pressure wave of the bomb was limited to travelling at the speed of sound?
It wasn't. Pressure waves can travel at supersonic speeds.

>>9109420
Isn't the speed of sound by definition the fastest a pressure wave can travel through a given medium?

>>9109449
https://en.m.wikipedia.org/wiki/Shock_wave
>When a wave moves faster than the local speed of sound in a fluid, it is a shock wave

>>9109399
Is it in any way possible that something like the US government developed a weapon in secret using something like this?

>>9109474

Probably not, as there's not much need for such a weapon.

Even in space, a nuclear bomb pumped laser is going to be better.

>>9109474
Only if they haven't tested it.

>>9109512
>no need for such a weapon

hold-up now.
1. Kinetic energy weapon (likely to penetrate)
2. High angle of attack (hard to stop)
3. Extreme velocity (hard to stop)
4. Tons of energy (very powerful)

Sounds like it would be ideal for hitting ICBM silos on the other side of the world.

>>9109518
Would it be obvious it was fired?

>>9109410
20km/s solar escape at mercury's orbit.

Anything faster won't orbit the Sun unless the periapsis is less than Mercury's orbit. On a semantics note I like perigee more than perisapsis but some retard decided that perigee is derived from 'ge' which is greek for ground, and other bodies can't have a "ground"

Typical comet is travelling 30-70 km/s when it reaches the atmosphere

>>9106399
>>9107499
is summerfriend so n/e/w he can't into search?

>>9109522
There's a global network of seismometers set up just to detect nuclear weapon tests. Air, surface, or underground, it will be detected if it involves nukes.

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>>9109958
Should have added, that nuke seismic waves are distinctive compared to earthquake seismic waves.

https://www.ldeo.columbia.edu/~richards/EARTHmat.html

>>9109419
>Mild steel, poor shape, and not much mass of steel.
It was not a literal manhole cover, though. According to Wikipedia it was a 900 kg (2000 lb) piece of armor plate.

>>9105723
https://www.youtube.com/watch?v=O2QqOvFMG_A

>>9106275
2000 km/s is nowhere near relativistic either

>>9110864
>tfw people don't realize the speed 'relativistic' implies

>>9107956
A casaba howitzer does, but the picture is a propulsion charge for the orion drive.

>>9111307

Yeah, and the Orion drive was propelled by a jet of tungsten plasma created via shaped nuclear charge.

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I'm interested in theoretical weapons and was wondering if you guys had some ideas for weapons that would operate by firing from Earth's orbit to locations on the surface.

>>9107986
and
>>9107956
are interesting but I'm not sure what else is practical.

>>9112881
You could fire any kind of weapon from orbit no? Even biological/chemical, radiation, microwave, laser..

>>9111843
Yeah, except the tungsten in this case isn't focused, so it won't destroy shit.

>>9112897
I'm looking for creative ideas to use as a superweapon.

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>>9112881
>>9113192

'Rods from God' is the the classic orbit-to-surface weapon. Shafts of tungsten the size of telephone poles, given a small push from an orbiting platform or rocket motor to drop their perigee and make them intercept your target on the surface at 7km/s.

>>9114274
cool, do they explode or just ballistic?

>>9114489
Just ballistic. but they have so much kinetic energy that they pretty much explode on impact anyway.