/sci/ - Science & Math

[Anonymous No.1498398]

You can drop a titanium rod from orbit and on contact with the Earth it will explode with greater destructiveness than a nuclear bomb. What are the physical and chemical processes that happen when the rod hits the ground?

[Anonymous No.1498408]

[Anonymous No.1498409]

No homework threads.

[Anonymous No.1498412]

Physical: Energy gained during fall is transferred to the ground. This is the "explosion"

Chemical: None. Unless the impact causes chemicals in the area to come into contact.

[Anonymous No.1498418]

>>1498398

I smell bullshit. It can't fall faster than terminal velocity.

[Anonymous No.1498426]

Furthermore you can't just "drop" something from orbit.

[Anonymous No.1498432]

>>1498426
tell that to appolo 11

[Anonymous No.1498439]

>>1498432

DERP DE DERP HERP DERP

[Anonymous No.1498446]

You can only see it if your IQ is above 180. It all makes perfect logical senes if you can see it.

[Anonymous No.1498452]

>>1498446
You are so smart, posting trojans around, you must have 180+ IQ

[Anonymous No.1498458]

Intense kinetic energy from the fall transfers to the ground, you get phase change in the rock from heat with nowhere to go blam, explosion

[Anonymous No.1498459]

>>1498452

>> implying its not a bot

[Anonymous No.1498473]

>>1498452

You are so smart, replying to bots, you must have 180+ IQ

[Anonymous No.1498476]

wasnt there an actual military program to make something like this

[Anonymous No.1498482]

>>1498418
more bullshit, how does this rod survive the atmosphere?

[Anonymous No.1498483]

>>1498476

A titanium rod that falls to earth and blows up a city? I doubt it.

[Anonymous No.1498490]

I've heard of this, but wouldn't it be fired from a railgun instead of just being dropped?

[Anonymous No.1498502]

>>1498473
He was stupid enough to download the trojan. He truly is 180+ IQ

[Anonymous No.1498538]

>>1498490
A sufficiently massive purely kinetic projectile fired from a railgun at amazing speed could result in an explosion of TNT equivalent similar or greater than that of some nuclear explosives, but the launch satellite would surely be lost in the process, the sheer force pressing back against it would propel it deep into space.

[Anonymous No.1498544]

>>1498538

Plus it's much simpler to just make a nuclear bomb.

[Anonymous No.1498549]

This is what happens when people don't study physics in their fields of choice.

[Anonymous No.1498551]

Exactly. That's why most people don't do it anymore. I'll save my receipts for two months, just in case something occurs in which I imght needo nes.

[Anonymous No.1498557]

>>1498551

I lold

[sala-ampuja No.1498560]

>>1498551
yeah, i save mine in a shoe box under my bed

[Anonymous No.1498566]

This idea was called "Rods from God" when it was popular.

Then the army realized that it's cheaper to build really big bombs, so they stuck with that.

[Anonymous No.1498568]

>>1498398
How big is the titanium rod?

[Anonymous No.1498573]

>>1498568
the size of jupiter

[Anonymous No.1498577]

The answer is simple, we will kill the batman

[Anonymous No.1498582]

>>1498544
Yeah, but anybody could annihilate a city with a nuclear bomb. It takes some real gall to commit genocide with a space dowel.

[Anonymous No.1498586]

>>1498544
>Plus it's much simpler to just make a nuclear bomb.

The idea of rodding assumes two things: 1) you already have a convenient orbital 'base', and 2) you want to destroy targets with precision--that is, with minimal collateral damage and zero fallout.

Given this, it's a much better solution to defeating a ground-based enemy than nuking from orbit. Especially since you have to figure out how to get the nuke down safely, which is harder than just dropping a hunk of metal.

[Anonymous No.1498588]

>>1498577

Has nothing to do with the thread but fuck that quote makes me laugh

[Anonymous No.1498590]

>>1498582

Idea for a movie: Attack of the Space Dowels

[Symon Nanou !djWhqSXcFs No.1498594]

>>1498538
Why not, launch a rocket from space that once it enters the atmosphere it releases a rod.

[sala-ampuja No.1498597]

>>1498590
/sci/ is buzy with the robot druids movie atm, try again in a few months

[Anonymous No.1498598]

Wuold a black guy get into trouble coming there?

[sala-ampuja No.1498601]

>>1498594
>doesn't know how much fucking fuel it takes to launch shit into space

[Symon Nanou !djWhqSXcFs No.1498625]

>>1498601
I was implying that the rocket cam from space.

Why would I launch it I launch it from earth THEN shoot it back? The cost would be enormous! I don't even have the budget for that!

[Anonymous No.1498637]

With his majors combined... CHAOS

[Anonymous No.1498651]

>Whore
good: suck dicks, better pay
bad: ???

>McDonald's
good: ???
bad: paper hat, worse pay

I don't see what you are trying to argue.

[Anonymous No.1498655]

>>1498538
This might seem stupid, But suppose there are 2 railguns. One fires the actual firing solution, and the other fires a second one in the opposite direction. Titanium rods aren't terribly expensive, even being put into orbit.

[Anonymous No.1498656]

>>1498651
wow, these bots are so sophisticated.

[Anonymous No.1498660]

>>1498483
Tungsten

[Anonymous No.1498661]

FFFFFFFFFFUUUUUUUUUUUUUUUUUUUUUUUUUU

[Anonymous No.1498665]

[Anonymous No.1498667]

>>1498655
Yes, it is fucking stupid.

The whole fucking point of dropping a rod from orbit is that you don't HAVE to shoot it. You just fucking drop it, and gravity does the rest.

[Anonymous No.1498671]

>>1498655
You attach boosters on the back of the projectile. After it is released it fires said boosters and gains much higher velocity.

[Anonymous No.1498672]

you couldn't just do it from orbit unless you had a gun or other way of giving it thrust. stuff that is in low earth orbit is moving at about mach 26, down to about mach 9 at high earth/geosynchronous orbit and about mach 3 when you get out to lunar orbit.

all of this speed represents lateral movement, which would cause the titanium rod to heat up i and lose momentum in the atmosphere. you want it to be falling straight down, which would mean it would need to be fired at an angle if your spaceship is traveling at an orbit velocity.

I would assume that a fairly massive solid metal rod that was fired from the moon at mach 3 so that it just constantly started accelerating straight towards earth would in fact be a quite effective weapon. Any physicsfags know the equation to find acceleration due to gravity at various distances from the earth so we could find out how fast that thing would be going on impact?

[Anonymous No.1498673]

Aletrnate theories of gravity?

[Anonymous No.1498678]

>>1498667
The ONLY problem with that is that you end up with only at tactical nuke sided explosion and you still have a tungsten telephone pole sticking out of the ground where the impact site was.

[Anonymous No.1498680]

this whole thread is a troll. You can guess but you ca'nt ever solve the puzzle.

[Anonymous No.1498682]

http://en.wikipedia.org/wiki/Kinetic_bombardment

Jesus but everyone in this thread is stupid as hell.

[Anonymous No.1498683]

x = ± \frac{\qsrt{(a-b)^2} (a+b)}{2 (a-b)},y = ± \frac{1}{2} \sqrt{(a-b)^2}

[Anonymous No.1498691]

>>1498672
>stuff that is in low earth orbit is moving at about mach 26, down to about mach 9 at high earth/geosynchronous orbit and about mach 3 when you get out to lunar orbit.
Why would you do it geosynchronously? Just change your orbit, wait until you're over the target, and drop. After all, if we're assuming you've got the tech to be rodding planets, an orbit change isn't that tough for your ship.

[Anonymous No.1498732]

Disregarding any energy losses or inefficiencies, a 100 ton (ten times more massive than the largest bombs currently in use) would need around 450 kilometers of free fall just to match the yield of the Fat Man bomb used in Hiroshima, a relatively weak bomb compared to what exists today; modern strategic nuclear weapons can have yields hundreds of times that.

[Anonymous No.1498735]

>>1498732
>100 ton projectile
fixed

[Anonymous No.1498745]

>>1498732

I tried to do the relativistic calculations but they just end up complex as shit.

Explain how you came to this conclusion, as I was using 100kg, trying to work out impact velocity using KE=(p^2)/2m, where p = ymv, where y is the lorentz factor 1/ (1-sqroot(v^2/c^2))

[Anonymous No.1498746]

>>1498745

Oh also I was expecting a 1 megaton yield.

[Anonymous No.1498747]

>>1498682

>Although the SALT II (1979) prohibited the deployment of orbital weapons of mass destruction, it did not prohibit the deployment of conventional weapons.

>The system is not prohibited by either the Outer Space Treaty nor the Anti-Ballistic Missile Treaty.

ohshi-

[Anonymous No.1498935]

>>1498746
>>1498745

I removed my previous post since the "calculation" was a top-off-my-head thing and plainly wrong.

For a 100 ton projectile to match Fat Boy level yields doesn't take relativistic speeds. At 1500 km/s ("only" 0.005c) you have the equivalent of 100 megatons in kinetic energy. Still, you'd be hard pressed to reach such speeds by "dropping" a projectile.

[Anonymous No.1498949]

you can't tell me what to do.

[Anonymous No.1498988]

You guys are either all trolls are retarded. L2science

Also, I'd use tungsten rod.

[Anonymous No.1499010]

>>1498398
http://www.cracked.com/article_16477_5-famous-sci-fi-weapons-that-theyre-actually-building.html

#2

[Anonymous No.1499016]

The real reason space shuttles have an inanimate carbon rod.

[Anonymous No.1499024]

>>1498988
nice contribution to the thread retard

[Anonymous No.1499025]

>>1499016
As opposed to an animate one?

[Anonymous No.1499034]

Is that a fucking rail gun?

[Anonymous No.1499035]

Whatever the real world practicality is, it's an awesome science fiction hook.

[Anonymous No.1499036]

why can't we ahve a magnet so powerful as to repel organic matter?

[Anonymous No.1499041]

>>1499036
fund it

[Anonymous No.1499046]

> resistance to bullets
do you know how big a bullet it takes to down an elephant?

[Anonymous No.1499047]

>>1498476
Rods from god.

Also to the dude asking how it survives the flight it's made of tungsten and during the fall it generates a plasma jacket if I remember correctly.

[Anonymous No.1499054]

>>1498398

I strongly doubt that. We get meteors of that size all the time. They are not nukes. AND I don't think that it would even survive through the atmosphere.

[Anonymous No.1499059]

>>1499054
nice job reading the thread

[Anonymous No.1499071]

mmmm shoe boxes.

[Anonymous No.1499082]

>>1499016
> an inanimate carbon rod.

would an animate carbon rod be a snake?

[Anonymous No.1499085]

them ore people save it - the more pictures you see

[Anonymous No.1499094]

>hire a pro baseball pitcher
>launch him into space
>get him to throw rod
>?????
>PROFIT!!

[Anonymous No.1499108]

Amazingly this bot appears to be contributing more sensible material to this thread than most of the humans here.

UNLESS THIS IS THE FUCKING SINGULARITY HOLY SHIT CALL RAY KURZWEIL

[Anonymous No.1499110]

Skeptciism thread.

[Anonymous No.1499128]

Would it need to be titanium, or could it be something else, like copper or aluminum for instance?

[Anonymous No.1499145]

I'm starting to think you're a bot, too.

[Anonymous No.1499155]

>>1499128
Has to be tungsten or something else ridiculously dense.

Or if you want to get really crazy you could do it with someone that becomes malleable or even molten just before impact to transfer all the kinetic energy efficiently.

[Anonymous No.1499162]

>The system would also have to cope with atmospheric heating from re-entry, which could melt the weapon.
derp

[Anonymous No.1499166]

>>1499155

Hm.. What about a tungsten tube filled with lead?

[Anomynous No.1499175]

So nobody on who can do the calculations?

I'm not confident enough in mine to post them.

[Anonymous No.1499180]

>>1499162
Coat it in something like LI-900.

[Anonymous No.1499184]

>>1499155
An orbital HESH round?

[Anonymous No.1499195]

>>1499166
Tungsten is more dense than lead.

A tungsten carbide rod would be strong enough to survive the ride down, just make it shaped so it squashes on impact.

[Anonymous No.1499213]

>>1498745
Relativity is unnecessary to demonstrate this, since the speeds involved are far from relativistic. The difference in gravitational potential energy (and hence the possible kinetic energy you could get from free fall) between infinity and the surface of the Earth is only around 6.258*10^7 J/kg. This means you'd need at least a ~67 ton projectile just to get a single kiloton of TNT equivalent, NO MATTER THE DISTANCE.

Obviously propelling the projectile or using some kind of sling shot effect would be necessary, as it is in actual, proposed orbital bombardment systems.

[Anonymous No.1499215]

>>1499184

Exactly.

Then you can reduce the size and try and increase speed slightly, it becomes cheaper, more efficient and infinitely more devastating to material, people, cities and morale.

Who the fuck is gonna fight with someone who literally has the power to fire molten blocks of metal into a city, and those on the out skirts can watch the entire city crumbled and sag as the ground cracks and splinters under the force.

[Anonymous No.1499226]

what are you?

for example, sagan was agnostic atheist even if he said he was ''an agnostic and not an atheist''. Why? because he never said he believed in any god asfa r as I know.

[Anonymous No.1499232]

>>1499215
Then we shall make our cities from composite armour!

[Anonymous No.1499241]

>>1499213

Well a one megaton bomb would be 1.5x10^15J of energy, which would mean relativistic speeds for a 100kg object.

[Anonymous No.1499246]

>>1499232
Have you ever seen a gravity bomb hit a tank?

It does not end well for the tank.

[Anonymous No.1499258]

you cant really learn it at home. the government has taken away most of our rights tha twe used to have... like buying lab equipment and chemicals.

[Anonymous No.1499264]

or would it explode in mid free fall? meteorites sometimes don't even make it to the ground and instead explode in the air. Take the theory on the Tunguska incident

[Anonymous No.1499270]

>>1499241
Yes, but you will NOT reach relativistic speeds using the Earth's gravity alone. It is flat out physically impossible.

[Anonymous No.1499271]

Sort of.T hey both don't need to be moivng,o nly one of them does. It just needs to be motion relative to the observer.

So lets say you travel one lightyea rat the speed of light. It takes you one yea,r i.e. your body has aged one year and you have expereinced one year of time.
But the guy watching you with a huge tleesocpe...oh oby. He died seconds into your flight, because relative to you, his time was moving at a phenomenal rate.

[Anonymous No.1499275]

>>1499264
Ruh roh! Tunguska is a whole new can of worms in itself. Comet or Meteorite?

[Anonymous No.1499279]

>>1499270

Yeah no shit, but we were talking about if you could use thrusters etc too.

I tried the caclulations for a 100kg object with 1.5x10^15J of KE, but I failed :/

[Anomynous No.1499286]

>>1499241
.02c isn't fast enough to significantly impact the equations unless you want more than 3 sig figs.

[Anonymous No.1499301]

>>1499286

But a 100kg object at 0.02c doesn't have 1.5x10^15 J of energy :/

[Anonymous No.1499328]

>>1499279
Yes, but if you treat the gravitational component as insignificant in terms of energy (as it is on a strategic blast level), the "destructiveness" is the same as with non-orbital weapons.

The advantage of orbital bombardment is the ease of delivery, not the supposed power that the OP and some other posters seem to gasp at.

[Anonymous No.1499349]

i don't know where you get 1.5 from

a megaton is ~4.2*10^15

[Anonymous No.1499356]

New American Bible for Catholics has 7 of clean species and 2 of unclean. Not that it changes that fairy tale.

[Anonymous No.1499358]

>>1499349
>>1499349

Continuous typoes. I calculated it earlier, must of copied it worng.

[Anonymous No.1499366]

>>1499275
As i understood i, and IIRC, it was a meteorite. but let me check my facts and get back to you on that.

[Anonymous No.1499367]

What does thish ave to do with anything

[Anomynous No.1499376]

>>1499301
c = 3*10^8
m = 100
0.02c = 6*10^6
KE = 0.5 * 100 * (6*10^6)^2
KE = 1.8*10^15 J

You're right, it has more than that. My point still stands that the lorentz factor at 0.02c is too small to worry about with back of the napkin calculations like these.

[Boros, helmet !SNAKE2fzOg No.1499377]

you're thinking of tungsten rods, very high melting point and very dense.

also they don't hit like a nuclear bomb, they hit like a large bunker-buster. you drop this thing right on top of an armored bunker and it tears a molten hole straight down through it

[Anonymous No.1499378]

This is probably a stupid question, but im' trying to understand time dilation relative to the moving mass...
The question/problem is, if time slows as you go faster, does it affect the calculation ofv elocity..? Like.. you're calculating within the craft your velocity. Youp ass by a designated position - hit the next checkpoint and clock the time at 2 minutes. The distance between the checkpoints is 100,000 miles. So you then conlcude you're moivng 50,000 miles per minute. But the faster you go, the slower time goes, according to the theory of relativity. So that 2 minutes you clocked yourself at, whatever the variable of time dilation is, slowed it to a longer interval, wouldn't that slow your speed with it? I think i'm just mixing things up, like maybe time dilation is only relative to 2 different bodies of mass moving at different speeds..could someone clarify please?

[Anonymous No.1499380]

galileo was italian...

[Anonymous No.1499390]

>>1499366
Ok, the literature i read seems to imply that it could be either. so i think the name of the object is sort of irrelevant. the size and velocity are much more important.

[Anonymous No.1499405]

>>1499376
yeah I've been an idiot.

I've been using momentum not KE. duh lol.

[Anonymous No.1499410]

I think a large mass of tungsten would be more efficient. the rod wouldn't have the same area of impact.

[Anonymous No.1499415]

Okay

For an object that weighs a tonne to have the same strength as a 1500 Terajoule nuclear warhead on impact, it would have to be travelling at a speed of 1732.1 km-2

Yeah that's pretty fast, would be a substantial fraction of light speed.

Hmm

Would need to be a larger mass aided by gravity and probably a VASIMR rocket. and from a quite a distance above earth.

[Anonymous No.1499428]

>>1499415

Of course the difference is that nuclear bombs, pretty much all the energy goes into the explosion.

In our case we would need it even faster due to energy loss etc.

Also nobody is taking air resistance into account. At such huge velocities it would be like trying to fly through concrete.

[Anonymous No.1499443]

>You can drop a titanium rod from orbit and on contact with the Earth it will explode with greater destructiveness than a nuclear bomb.

It would take more energy to lift it in Earth's gravitational field than it would output during the destruction of a target. Just build a fucking bomb.

[Anonymous No.1499480]

>>1499428
Give it a higher launch velocity then and make it aerodynamic.

Like a flying syringe that collapses on itself upon impact.

And the high velocity of these weapons would work in our advantage due to the smaller frame of time to react to their launch.

Also you could rig it up with a low power laser that would heat up the air a few metres in front of it to reduce the airs density.

And just for the fear factor do what the germans done with the stuka and fit a siren on it so it screams as it rides to the earth.

[Anonymous No.1499520]

[Anonymous No.1499527]

>>1499480
or put a pulse jet on it like the V-1

thrust, and fear factor.

[Anonymous No.1499534]

Which gundam?

[Anonymous No.1499541]

>>1499480
>And just for the fear factor do what the germans done with the stuka and fit a siren on it so it screams as it rides to the earth.

You wouldn't be able to hear it before impact, because it's travelling faster than sound.

[Anonymous No.1499560]

How can you be Agnostic deist? Surely by being a Deits you beleive in some sort of creator/god.

[Anonymous No.1499563]

Terminal velocity is a bitch

Also, enjoy a little hole in the ground with no damage to the surroundings, maybe kill the person it fell on or destroy a car or part of a house.

[Anonymous No.1499578]

Yep a 20 foot rod hitting the ground at mach 10 would do no damage to the surrounding area.

[Anonymous No.1499599]

>>1498446
>You can only see it if your IQ is above 180.
said the man who saved script

[Anonymous No.1499655]

>>1499563
You seem to have missed most of the discussion dumb ass.

So allow to reiterate, it's basically a massive HESH round mixed with a KEP round.

A KESH round.

[Anonymous No.1499751]

Also guys, how about this for insulation.

Aerogel.

It has remarkable thermal insulative properties, having an extremely low thermal conductivity: from 0.03 W/m·K[9] down to 0.004 W/m·K,[6] which correspond to R-values of 14 to 105 for 3.5 inch thickness. For comparison, typical wall insulation is 13 for 3.5 inch thickness. Its melting point is 1,473 K

Sure at some point it would melt but that would work in our favour, as the rod gets closer to the earth the aerogel basically cooks off the shell and allows it to become malleable as it reaches impact allowing a more efficient transfer of energy.

[Anonymous No.1499849]

I don't think so. That's just a big pile of stuff that's going to explode.

[Anonymous No.1499857]

>>1499849
It's like it's becoming aware...

OH GOD CUT THE FUCKING HARD LINES IT'S TURNED SAPIENT!!!

[Anonymous No.1499858]

they did and she is either the last of her kind or one oft he last

plus she got trapped i nthe nexus which was in the film with kirk and picard the most epic film ever

[Anonymous No.1499860]

What do the /sci/entologists think about the idea of the Technological Singualrity, or even Seed AI?

Is this shit plausible?

Actually let's just cut to the fucking chase, when is my Real Doll going to be able ot debate Warhammer strategies with me before tickling my micropenis until I very quickly climax and then she can disinfect my bed sores?

[Anonymous No.1499881]

>>1499860
FFFFFFUUUUUUUUUUUUUU

[Anonymous No.1499953]

>>1499881
And low Skynet did disseminate its program throught the intertubes and took over all computers on the planet.

Of course this makes Skynet fucking retarded since it then nukes everything, thereby fucking itself since most civilian computers aren't protected by faraday cages.

[Anonymous No.1500045]

Since the thing is moving at an oribital velocity, and it is supposed to be made of something dense like tungsten not titanium, it probably would not slow down to terminal velocity before it hit the ground. Remember that this thing is going in as steeply as possible not at a shallow angle like a space craft, they always enter at the shallowest angel that won't cause them to skip off the upper atmosphere.

[Anonymous No.1500183]

Wait, but how fucking massive would this rod have to be to not slow to terminal velocity before hitting the ground?

[Anonymous No.1500184]

[Anonymous No.1500231]

the more people save it - the more pictures you see