Slashdot Mirror
Congressional Candidate Brianna Wu Claims Moon-Colonizing Companies Could Destroy Cities By Dropping Rocks (washingtontimes.com)
Applehu Akbar quotes a report from Washington Times: A transgender-issues activist and Democratic candidate for Congress says the advent of the space tourism industry could give private corporations a "frightening amount of power" to destroy the Earth with rocks because of the Moon's military importance. Brianna Wu, a prominent "social justice warrior" in the "Gamergate" controversy who now is running for the House seat in Massachusetts' 8th District, suggested in a since-deleted tweet that companies could drop rocks from the Moon. "The moon is probably the most tactically valuable military ground for earth," the tweet said. "Rocks dropped from there have power of 100s of nuclear bombs." After users on social media questioned her scientific literacy, the congressional candidate clarified that the tweet was "talking about dropping [rocks] into our gravity well." Small space rocks can indeed do nuclear-weapons-scale damage if hitting the Earth at orbital speeds. But launching one from the moon, even setting aside issues of aiming, would still require escaping the satellite's gravitational field, a task that requires the power and thrust contained in a huge rocket.
Original submission: Brianna Wu Is a Harsh Mistress.
You stripped this brilliant title and wrote in your blurb that spans two lines!
a.k.a. The Moon Is a Harsh Mistress from Robert A. Heinlein
Dropping rocks from the Moon? "Dropping" them?
And who the fuck would waste so much money and energy trying to fling shit from the Moon when it's cheaper to use nukes from Earth itself and harder to intercept due to shorter distance?
I still can't believe Wu's parents wasted 500k on this idiot's education. That much money should at least have produced some basic education in physics, and some common sense, even in the stupidest person on this planet.
The head of the House Science Committee spends all of his time denying and attacking science. She'll fit right in:
http://www.slate.com/blogs/bad...
Well, since https://mycroft.ai/ is progressing nicely, maybe we could use it as central AI for all infrastructure on moon.
Someone quickly write a projectile-steering skill.
n/t
Avantgarde Hebrew science fiction
Any genetics company could unleash killer microbes on Earth.
Agricultural companies could cause mass starvation if they wanted to.
Any company running nuclear power plants could contaminate large areas.
Any company manufacturing or using explosives could build bombs.
What's the problem with dropping a few rocks?
The lunar module got off the moon with not much thrust at all, look at the size of it compared to the whacking great rocket that got them there...
Doesn't take all that much to escape the moon actually, you don't need a rocket the size of one required to get off earth...
Aiming, fair enough though.
"The Moon Is a Harsh Mistress", Robert A Heinlein, 1966
Would someone please inform Ms. Wu that while there may be many people who are interested in what she has to say, that does not give her license to go speculating far outside her field of speciality (which I'm fairly certain consists solely of electronic entertainments). ...Actually on second thought, that's probably exactly why she'd fit right in with Congress. Get her on the House Science committee with Lamar Smith; I'm sure they'd get along famously.
There you have it, people! Corporations are just waiting to throw rocks at you from the moon!
Can someone please give this woman an award for being so stunning and brave?
Brianna Wu took her husband's fanfic for campaign strategy.
Ok that Brianna person is a fool, no doubt but then what about moronocy of the submitter who said "Small space rocks can indeed do nuclear-weapons-scale damage if hitting the Earth at orbital speeds." ??? Wtf
Small rocks hit the earth all the time at orbital speeds and they burn up in the atmosphere. Even if it didn't burn up in the atmosphere, a small rock at "orbital speed won't do much damage. Even without an atmosphere (which we have btw, last time I checked it would need something measured in tens of feet in size). Good luck getting to orbit, accelerating, and maneuvering such a large object without anybody noticing.
1) Invent anti-grav drive.
2) colonize moon
3) build rail gun like rock launcher
4) world domination
No, you just have to roll the rock over to the edge of the moon and push it off. Simple. No need to lift it.
Liberally who?
your thin skin doesn't make me a troll
It's better to keep your mouth shut and have people think you're an idiot than to open your mouth and remove any doubt that might remain.
Maybe she should concentrate on social issues. Physics ain't her strong side.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Looks like someone has read "The Moon Is a Harsh Mistress" :-)
Lo and behold, for I am a sig!
They hate science because their religion demands it of them.
Here we go again.
I am sure there are trans people out there who are actually well educated in astronomy, physics, and have common sense to not tweet shit they don't know anything about;
and they are currently covering their faces with their hands and thinking "What the fuck did we do to deserve this idiot as our representation?"
I know that the US Congress is filled with idiots, but that doesn't mean that the first trans person needs to be one as well and serve
as a stain on the community's reputation.
I am sure there are corporations out there somewhere itching to nuke their sources of income, in some parallel imaginary Universe that can only exist in books.
Rocket power? Science fiction has typically suggested that you would use magnetic accelerators to send rocks from the moon to the earth, probably with solar power. It's not trivial, but it's theoretically possible to launch stuff from here to there using these means, let alone from there to here.
I'm not suggesting that it's trivial, far from it. You have to build the track and then you have to build the projectile. But if you're going there to build heavy industry, then yes, you absolutely could throw masses at the planet relatively cheaply.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The physics might work, but even assuming the technology is developed I doubt earth governments would allow the construction. And they'd have a lot more power at their disposal - 1 nuke would be the end of it.
News at 11
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
That's brilliant, but what if it hits a turtle?
Turtles don't eat green cheese.
"National Security is the chief cause of national insecurity." - Celine's First Law
You're talking about him, right?
The first intelligent question does not deal with the physics of bombardment, an idea that Heinlein uses in more than one novel. It's why: Why would corporations think throwing rocks at their life-support system is a good idea? If they start 'breaking' this planet, they'll be forced to fix it, for free. It will take many decades to determine which plants and animals can survive and grow in a low-gravity biosphere. Until then and until the moon-base biosphere is totally solar-powered, it will need the Earth for power, food and even its atmosphere. Once again we're avoiding the physics, in this case of carting construction materials from the Earth, to build a moon-base. It's difficult and expensive and thus, won't be happening for a very long time.
Another idea that Heinlein had, was weaponized low-earth orbit: Not ships with weapons, like we see in so many sci-fi movies but dozens of weapons aimed at the Earth, like in Space cowboys (2000). That will be much easier to build and launch and needs to be on any agenda about exploiting space.
One of my favorite dialogues from The Moon is a Harsh Mistress was when the computer recommended not using the catapult to launch boulders against Cheyenne Mountain anymore. When they asked the computer "Why?", it replied "Because it's not there anymore."
"a task that requires the power and thrust contained in a huge rocket"
You actually don't need a big rocket to escape Moon's gravity. You know, as proved by the Apollo program. If we are talking about the situation after we colonize Moon, at that point we will obviously have the technology needed to send a rock back to Earth from Moon. It will be needed for the colonization. So she is not scientifically wrong, although worrying about people throwing rocks from Moon to Earth has got to be in the top 10 least important problems humanity needs to solve.
Equality will not come by enforced inequality. If anything, it breeds contempt and hands fuel to those that wish to oppose it.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Homeopathic WMDs! OMG!
So, let me see if I have the summary right:
1. Take a large rock in space
2. Dilute that rock with space, yielding a large space rock tincture
3. Repeat the process until you have a small space rock tincture
4. Drop the small space rocks on Earth, from the height of the moon (works because the moon is "up" and the Earth is "down")
5. Kaboom!
6. ???
7. Profit!
My god! What if she thinks to use space dust, instead! The more you dilute a homeopathic tincture like that, the more effective it becomes! We're all doomed!
Why didn't the moon drop on earth? Let's shoot it out of the sky to save our lives!!!
would start first by throwing paper to the moon
. . . .running against an established Congressman (Stephen Lynch) who has been in Congress for 16 years, who has routinely been winning elections by 70%+ for years.
Wu's only real "in" here, is that Lynch is considered moderate. No idea on how that particular congressional district trends. . .
Keep electing retards.
Yeh... that will make things better.
I honestly don't give a shit about Wu's gender issues. Her gender has no relevance whatsoever on her ability to perform the job. It's that she's another useless shitbag politician wannabe that lacks anything other than an education in manipulation of other people that is the problem.
She's a fucking retard and counter-accusations of sexism or genderism will not deflect this fact.
"Brianna Wu references Heinlein, Dumb Puppies Don't Know Which Side To Take"
All you'll hit is the moon and not that hard.
Wanna buy a shirt?
https://www.redbubble.com/people/stealthfinger/shop?asc=u
Her claim to fame is being a victim of harassment. She is challenging a successful incumbent with broad appeal, whereas her own policies are niche concerns. She has a very high opinion of herself but is not all that bright and terrible at politics. Essentially she's a crank. Don't give her the headlines.
If we have anything which travel between earth and the moon and a colony premanentely built, THEN it is safe to assume that kinetic bombardement is possible. The energy requirement to take off the moon are not that much compared to earth: escape velocity of the moon is only 2.4 km.s-1 or thereabout and without atmosphere it is far far easier to do that than on earth, you can imagine a gun like contraption which would work on the moon (no atmosphere so no aerodynamic break) or much smaller rocket.
The reason why this is stupid is because it would takes a long time to travel between the moon and earth, and so the retaliation or countermeasure would be ready. But if we HAVE a colony on the moon, then it is certainly a consideration to have knowing the beligerent nature of man.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
More or less any industry on the moon would need a "cheap" way of getting mass to Earth. Without that, there's no point in putting the industry on the moon.
So when the BigBadBallBearing company builds their factory on the moon, they will include the means to get their products back to Earth, and those means, like many other tools, can be used for good or bad purposes.
- The Sigless Wonder
"But launching one from the moon, even setting aside issues of aiming, would still require escaping the satellite's gravitational field, a task that requires the power and thrust contained in a huge rocket."
Now you're just trolling. The Apollo moon landers managed to take off from the moon with a very small rocket. Yes, you'd need a comparatively larger one to launch a large rock, but the summary is misleading. It certainly wouldn't be a huge rocket. Now, you'd want to launch it retrograde from the moon's orbit so it would be moving slower than the moon's orbit around the Earth. That would make it take on an elliptical orbit around the Earth that picked up speed as it approached the Earth. The moon is going about 3.68 km/s in orbit and the escape velocity is 2.38 km/s so you'd only be going 1.3 km/s relative to Earth. You'd have to kill enough velocity that it would actually hit the Earth, but you're already 2/3 of the way there by escaping the Moon's gravity so it's not a "huge rocket" at all. In comparison, the delta-v required to actually get to the moon is somewhere around 15 km/s. This is basically straight from the plot of "The Moon is a Harsh Mistress." If your goal was to hit Earth with a big rock, you'd probably find it easier to do an asteroid redirect mission and nudge a large near Earth asteroid onto an impact course. Getting to the moon in the first place is about 15 km/s delta-v but getting to a near-Earth asteroid is more like 13.5 km/s, and then you can use something like a small ion thruster or solar sail to nudge it around and hit the Earth 3 passes later.
"I have never let my schooling interfere with my education." - Mark Twain
... when totally clueless people try to be smart?
We suffer more in our imagination than in reality. - Seneca
The turtles are 100% covered by the elephants, so the turtles will be perfectly safe.
Good point. Forgot to consider that. Thanks!
So, we're quoting verbatim from The Washington Times as if it were a trustworthy news source and describing harassment victims as "Social Justice Warriors" now? What the hell? Is Slashdot an alt-right mouthpiece?
4300 km/h is my first rough guess of the needed Moon-relative launch velocity to kill the Earth-relative orbital velocity that the Moon naturally grants the projectile.
Given the mass requirements of high velocity atmospheric-entry I suspect that's a pretty big launcher needed.
Is not entirely hinged
" a task that requires the power and thrust contained in a huge rocket. "
You don't need rockets to launch rocks, in the book they used a rail-gun that needs only electricity, no fuel.
If you recall, the moon has only 1/6th of earth's gravity.
She should have asked her brother Louis Wu, before making an ass of herself.
Why should I feel represented by someone just because they happen to have something in common with me?
I'll bet this is true of most self-appointed representatives of interest groups.
I'd even wager to say that there are a lot of racists who turn on TV and see some neo-Nazi and think "that guy is so dumb".
We go to the moon.
We establish a project. Let's call it the Alan Parson's Project.
We toss some moon rocks off the moon.
Maybe some of them have "LASERS" on them.
???
Profit?
If they start dropping rocks from the Moon on us, we will drop rocks on the Moon to destroy their bases there.
Anyone can run for office regardless of how ignorant, stupid or otherwise batshit insane they are. We see it all the time. It shouldn't be a surprise that it's happened again.
OK, we get that Slashdot hates Brianna Wu. We know that there are few harsher adjectives around here than the dreaded "Social Justice Warrior". We get that compared to the Slashdot voice, Brianna is a Communist (although compared to the Slashdot voice, Ronald Reagan is one, too).
What makes this front page entry a disappointment though is how far it wandered from reality just to attack one person. All that is being discussed here is the possibility of a kinetic weapon - which has had an entry on wikipedia for over a decade. Wu's statement was then twisted to be used as an attack against her.
And seriously, what does Slashdot have to gain by attacking her, anyways? She wants to represent Massachusetts. Most of Slashdot would see the majority of the voting public in Massachusetts to be total Communists regardless, and if Wu doesn't get the nomination some other person of similar political persuasion will.
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
First that nuke would have to get to the moon... and could easily be destroyed by simply shotgunning it with small rocks.
.......
If I were some evil company CEO, I would prefer to drop rocks from L1 of Moon-Earth. It's all about economy.
I'm sorry, I thought it was March 1st, not April 1st.
Heesh needs a non-gender-specific pronoun to refer to hirm.
Since the US Military has contingencies for everything from Elves on unicorns to mass clones attacking with bent spoons, I bet they've got a plan in case China or Russia gets a foothold on the Moon.
http://www.deepfreeze.it/article.php?a=monster
Is "social justice warrior" a term used outside alt-right circles or hateful misogynist adolescents now?
I will keep dropping the rocks.
How hard would it be to magnetically launch a 10 ton meteor out of the moon's orbit? Say 12 ton 1/6 equals 2 tons or 4000 pounds. Then add in the fact that there is no friction from air. It feels like something relatively straightforward.
How exactly are you going to aim your km-long railgun?
Lacking basic scientific comprehension is a requirement to run for Congress. She'll be great.
"Ms. Wu blamed criticism of her on sexism: “that’s the danger of being a woman on the internet!” she exclaimed.
“Like, you all can make fun of that statement, but it will still be true,” another Wu tweet said. “This is why the militarization of space is so dangerous.”"
But... YOU ARE NOT A WOMAN. You are a DUDE. I'm sorry, but you can't put on a dress and stuff your shirt and suddenly claim every criticism is "because I'm a woman".
This is exactly how Ming and Flash got started.
Original submission: Brianna Wu Is a Harsh Mistress.
Exactly. And the Heinlein reference answers the point made in the last line of the summary, that it "would still require escaping the satellite's gravitational field, a task that requires the power and thrust contained in a huge rocket.":
You wouldn't use a rocket. You would use a mass driver.
With that said, it would take some pretty big rocks to project the "power of 100s of nuclear bombs." But, assuming by "rocks" you mean quite large boulders-- a hundred thousand tons or so-- the statement is accurate.
http://www.geoffreylandis.com
Only an idiot would expect a fully thought out, researched and authoritative position to be presented in 140 characters or less.
Would you share a jail with a lion? (or a cave, perhaps more in religious context)
Yet we are more dangerous than lions (OK, maybe not in a jail). How can we live together?
We function on the assumption there are mutual interests in being non-aggressive. There's no other way, as living with the necessary precautions would render human society not viable.
It's not different at bigger scales. We must create a way to prevent aggression. Power is growing to the point of making defense impossible.
There are two possible ways ahead:
1. Preemptive attack, which will mean turning evil (at least), may not work and, if it doesn't work, you may forget any hope of striking any deal for an Alliance -- who wants to join someone who's evil? You'll then have to say foolish things like "everybody is evil" -- which means there's no hope for good on Earth. Great idea.
2. Realize force will not solve that and strike a non-aggression deal before there's a need for defense. You can carry a gun in the hopes of defending from another guy with a gun. But weapons cannot help after the fact -- like in the case of the Boston bombing. Wars among countries are way, way worse. You may lose a city or two, before even knowing who attacked. Of course, this includes creating a neutral, provenly impartial, international force (as a Police of sorts).
I foresee there will be problems with alternative 2, but 1 really becomes doom at one point in the future.
fck you, prcks
By comparison the LEM weights 2 tons dry and 15 tons total, with 8 tons fuel.
Uh, but that's to land and then take off again. The LM Ascent Stage is what you need to compare to:
Dry mass: 2,150 kg
Propellant mass: 2,353 kg
--but, as noted above many times, nobody's suggesting a rocket to do this. Heinlein proposed this decades ago. You'd use a mass driver.
http://www.geoffreylandis.com
Depends on what you mean by "small".
On a scale of asteroids, I'd say "small" means less than a kilometer or so in diameter.
http://www.geoffreylandis.com
I see a lot of people deriding this but isn't this the same thing as the Kinetic Bombardment as described by the below Wikipedia article? Is there something inherently wrong with her assertions, or is the density of rock found on the moon not conducive to this kind of attack?
https://en.wikipedia.org/wiki/...
That's absurd. You require to build a big cannon to push the matter to a colission orbit.
So... it's a weapon.
And there is a lot of ways to build weapons a lot easier that go to the Moon to build a cannon.
No problem. If we just order everyone on earth to jump up and down simultaneously, then it will cause quakes on the moon because the earth is so much bigger...
Just imagine you are the company that colonizes the moon and you have a large base with some self sufficiency and a method get cargo to the moon
and back to earth. This all would require some profitability like from exporting some natural resource of the moon or maybe, but less likely, from just
the tourism. In that case, in order to keep your monopoly and in absence of any supervision by a government, you would have to build up some
defenses against competitors or other entities that want to take the moon from you. And as soon as you have those defenses, why not use them to
increase profits? What could happen to you? They can't get you on the moon that easily, you have the high ground.
***Quis custodiet ipsos custodes***
She must have read Heinlein's "The Moon is a Harsh Mistress"
If you try to lecture others about gravity in space without an astrophysics degree you surrender your right to preferred pronouns, thus your new label is dumbshit.
From Back to the Future Part 4, 2045.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
About three or four times the speed of a hyperloop, actually. Musk could probably be paid to just do it.
The only the a moon colony needs to drop onto Earth from the moon is Brianna Wu.
Dear Slashdot editors: Not every dumbass in the world needs a soapbox.
I recently played a game-based documentary about this projection. It was called "Call of Duty: Infinite Warfare."
... all candidates for elected positions should be forced to go through a mental health check...
I personally would say that grabbing somebody by the sexual organs shows contempt for them.
The Washington Times despite the quite official sounding name is at best a right-wing news site. The site has had problems in the past with accuracy. I much rather see an article that includes the entire comment in context.
I won't comment on what Brianna said or didn't say because frankly this entire submission reeks of fake news.
Al Gore goes to her for Global Warming... Climate Change .... WTF.. advice.
And you don't even have to aim for the planet itself but merely the edge of the Moon's [rather shallow] gravity well; the Earth'll "take" it from there. ;)
1 nuke would be the end of it.
Yeah, an airburst oughtta be particularly effective...
Brianna Wu just watched last episode of The Expanse before making the statement?
Stop publishing about this bitch. She does not deserve the attention.
I you're that desperate for a woman game developer, I would be happy to give you a referral, but Brianna Wu she is not. The person I would refer to you also does not produce sexualized artwork that is demeaning to women. Only problem with my referral is that she wasn't born with a fucking silver spoon in her mouth.
(No, AC, I don't need you to remind me what Wu's boy name was because I don't care. Her name is Brianna. Get over it!)
How hard would it be to magnetically launch a 10 ton meteor out of the moon's orbit?
As engineering projects go, launching a rock jacketed in iron from the surface of the moon is a large but understandable task. As I and others have pointed out elsewhere in the thread, a mass driver is a probable construction on the moon anyway if heavy industry is built there.
As has also been pointed out elsewhere in the thread, it's not even worth mentioning right now. That's a long way away, and oh yeah, odds are that any such facility will be controlled by one or more governments anyway, and not left in the hands of the corporation[s] that build it.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Yes, it's possible. But not very economical with modern (read: non-fusion) tech, because the amount of energy is very high by current standards. A couple of fission plants would also do it, but at that point you might as well just build a nuclear bomb, which is more portable and easier to hide than a lunar rock-launching mechanism.
"Small space rocks can indeed do nuclear-weapons-scale damage if hitting the Earth at orbital speeds. But launching one from the moon, even setting aside issues of aiming, would still require escaping the satellite's gravitational field, a task that requires the power and thrust contained in a huge rocket."
I think she's a kook and a nutter, but she's not as wrong as presented by the poster.
IANARS, but...
Pretty sure it's 10+kg rocket to put 1kg payload in LEO, where doing the same on the moon is what, maybe 1/6 of that?
The Saturn V had 2400 tons of fuel to put 15 tons of LEM on the moon, or a ratio of about 150:1.
Going the other way, though, all you have to do is escape the moon's gravity well and it's 'downhill' to earth, so more like 3:1.
Meaning to drop a 300kg (earth mass) rock would 'only' take 1000kg (earth mass) of fuel...but of course to do meaningful damage (let's use Tunguska as a bottom-limit) would require a rock of 20-100m diameter, ie 9800 TONS (needing 30,000 tons of propellant, even from the MOON).
So, no: not realistic anytime soon. Even Heinlein IIRC postulated mass-drivers pushing essentially lunar GRAVEL off the surface of the moon, not giant rocks at a single go.
-Styopa
Probably not, or my wife would be all over my junk...
I believe the since-deleted tweet was not about accidents, but deliberate attacks. As in "stop taxing us or we'll start dropping rocks on you". Or possibly the scenario from a certain Heinlein novel ... but I believe that the conflict will be more about taxes and less about representation.
Nukes lose a lot of their destructive power when they can't generate a compression wave e.g. the near-vaccum of the lunar surface.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
Liars don't do well in elections? lol. You live in a strange world.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
Wish someone would drop a big rock on this twit. :(
Maybe people are taking the "drop rocks from the Moon" too literally, might be more of a Corporate Asteroid miners using the Moon as a convenient way-station, could alter an asteroid’s solar orbit to intersect with the Earth's solar orbit and crush an offensive country like Tunguska Forest.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Homeopathic WMDs! OMG!
So, let me see if I have the summary right:
1. Take a large rock in space
2. Dilute that rock with space, yielding a large space rock tincture
3. Repeat the process until you have a small space rock tincture
4. Drop the small space rocks on Earth, from the height of the moon (works because the moon is "up" and the Earth is "down")
5. Kaboom!
6. ???
7. Profit!
My god! What if she thinks to use space dust, instead! The more you dilute a homeopathic tincture like that, the more effective it becomes! We're all doomed!
Substitute "rock" with "brain" and you pretty much have her level of intellect.
I personally would say that grabbing somebody by the sexual organs shows contempt for them.
Or perhaps fondness.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
The Earth will take it in the same way that it took the moon - it will enter Earth orbit. Starting from a lunar orbit, you need quite a lot of energy to move it into an orbit that intersects the Earth (or even intersects the atmosphere enough that eventually friction will decay the orbit into one that hits the Earth).
I am TheRaven on Soylent News
Can we not re-post crap from the "Washington Times"? This is slashdot not breitbart....
Which of course is what was used in the moon is a harsh mistress, catapult style launchers. Of course if you built the asteroid killers it would be fairly easy to break the rocks into smaller pieces. (Since the rocks would be on well defined trajectories and take about 3 days to reach earth)
Wouldn't it be a lot easier, in energy terms, to de-orbit an asteroid from the Belt than to get rocks off the Moon?
holy shit, r1384's lobbing spoilers at us from the moon!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
A working Hiroshima style fission bomb isn't that hard to build, which is why the Little Boy bomb had that particular design. But getting the 64 kg of fissile materials you need to build one is a bitch. Unlike as depicted in many bad post-apocalyptic novels, you can't produce bomb grade nuclear fuel in a basement or a small cave. It requires massive industrial facilities and leaves evidence which is impossible to hide. That's why non-state actors have never been able to produce a nuclear weapon, despite the fact that such as weapon is highly desirable and some of them are well-funded. And there's getting the uranium in the first place; you need a theoretical minimum of about nine tons of purified but unenriched uranium to start, and in practice quite a bit more if you don't have forever to do it.
For a private actor, obtaining a nuclear weapon is extremely unlikely, barring some breakthrough in physics or chemistry.
Dropping a big space rock, on the other hand, is limited not by physics, as you suggest, but by economics. At present it's economically impossible, but if there were private space activities such as near Earth asteroid mining, everything you'd need to do it would be there, so the only missing piece would be intent. As for using lunar materials, the same applies, it's just farther off because the cost of getting stuff out of the Moon's gravity well means lunar mining is only attractive for materials destined for space use.
And note that even if obtaining a nuclear weapon were considerably easier than it is today, you still couldn't rule out an opportunistic space attack. It could be the guy running the mining scow, or even hacking an automated vehicle's software. That's something well within the capability of a wealthy individual, not to mention state actors.
At some point we're going to have to deal seriously with the space rock attack scenario. But that's decades off. When someone starts a project to move dense masses in space on the order of a metric ton or so, that's the time that governments need to step in with oversight. Right now it's still in the realm of sci fi.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
transgender-issues activist & social justice warrior.
It looks like Wu is just trying to give me false hope. After all, how could anyone target the sodomites and perverts with such rocks? It isn't like they all cluster together in specific cities like San Francisco or Austin Tx. or Chapel Hill N.C. where the problem could be easily resolved.
I'm an American. I love this country and the freedoms that we used to have.
The Moon Escape velocity is 2.38 km/s while on Earth it is 11.186 km/s.
Since energy is proportional to the square of the speed (E=1/2*m*v^2) we can conclude that it is (11.186/ 2.38)^2 = 2 time easier to reach free space from the Moon than from Earth.
However, even if a rock is launched from the Moon at 2.38 km/s, it still inherits the inertia of the Moon. Simply speaking, the rock would not fall to Earth. It would be in an orbit similar to the Moon orbit.
The orbital speed of the Moon is about 1km/s so the rock must be given that additional acceleration to cancel its orbital speed.
At that point, the rock is immobile (from the Earth point of view) and it will start falling toward Earth because of ... gravity.
When it reaches Earth, its speed will be equal to the Earth Escape velocity (a bit less in fact since the rock did not start falling from an infinite distance) so 11.186 km/s.
The kinetic energy is given by the formula 1/2 * m * V^2 so for 1kg the kinetic energy at 11km/s is 1/2 * 1 * 11000^2 = 60 * 10^6 Joules
As a comparison, 1kg of TNT provides 4 * 10^6 Joules so each kg of moon rock would be equivalent to approximatively 15kg of TNT
The Hiroshima bomb was 15 kilotons of TNT = 15 * 10^6 Kg so a similar effect would require a 1000 tons of Moon rock and the ability to accelerate that rock to a speed of 2.38+1 = 3.38 km/s.
Now-a-days it seems you need to be a qualified liar to win elections.
You think a nuke needs an atmosphere to be effective?
50 million degrees C will vapourise anything.
Escaping the moon's gravity is the easy part. The moon is in a really high orbit. To get something from the moon to the Earth, you need to either lose enough of your angular momentum to fall
It turns out, however, the higher an orbit is, the easier it is to kill your angular momentum and drop. So the fact that the moon is in a "really high" orbit helps here. You need about 1 km/sec to kill the moon's orbital velocity, actually less than the 2.38 km/sec escape velocity to throw the rock off the surface.
But delta-Vs don't add; energies add. Once your mass driver has gotten your rock to 2.38 km/sec, it only takes another 0.2 km/sec to kill the orbital velocity and make it drop. (Less, if you want to take an indirect trajectory via the "fuzzy boundary", but those take a lot more time).
...and, yes, actually I am a rocket scientist.
...
TL;DR: If it were easy for things from the moon to fall to Earth, the moon would have fallen down already.
In fact, rocks splashed off of the moon actually do hit the earth, of course: http://meteorites.wustl.edu/lu...
http://www.geoffreylandis.com
I'd put it at least an order of magnitude smaller than 1km...
Since "small" is subjective, you can certainly define it like that if you like.
By your definition, a "small" rock from the asteroid belt will still "indeed do nuclear-weapons-scale damage if hitting the Earth at orbital speeds."
http://www.geoffreylandis.com
I can't just stand on the moon, chuck a rock at Istanbul and knock it back to Constantinople?
APK quotes people (including myself) without context and should not be trusted. Just thought you should know.
Oh, maybe because it IS science fiction. Sounds very much like the plot in seveneves by Neal Stephenson (worth a read if you're interested), where the moon blows up and earth is scorched from the falling debris.
Brianna, that's not how this works.
That's not how any of this works.
So...colony drop?
Going on with that logic, there are dangers right now that are far bigger yet we do nothing about.
Anyone who can drive a large vehicle is a risk. They can drive through pedestrian plazas. They can be crashed into buildings. They can be loaded up with explosives and used for violence. Even so, people are allowed to drive cars, trucks, and delivery vehicles through cities.
I don't think any rational person would deny a risk exists: any nation or company who can send stuff up to space can also have stuff crash back to earth. This applies just as much to military ICBMs as it does to satellite launches as it does to SpaceX rockets. If a person or group is able to launch equipment to colonize the moon then yes, they would also have the capacity to destroy earthly cities.
But short of international treaties and each nation's own domestic policies, there isn't much that can be done about it. There are risks to life, there are even risks of death and injury in my daily commute, but I'm not changing plans because of those risks. If someone were to hack into the international space station's guidance computers and cause it to crash land on Washington DC or the Kremlin or Tokyo's imperial palace, a US law is not going to prevent that.
//TODO: Think of witty sig statement
...for reading The Moon is a Harsh Mistress, at least.
CyberKender
Apparently Appointed Lord Mayor of There
The moon is tidally locked. Mass drivers that get to 2.6 km/sec are going to be of fixed orientation.
Heinlein got around this by positing food deliveries from the moon to earth...I'm capable of suspending disbelief to this extent. (Not like he's suggesting a mars colony staffed from the parking lot after a Dead Show, at 6 AM.)
IMHO just building a mass driver capable of hitting the earth with a fairly direct orbit, would be seen as a very aggressive act. If you mass driver is built to send supplies to a Lagrange point, you're going to have to do trick shots (lunar gravity slings anti-orbit.), requiring long lead times (half a month from firing to gravity sling). Not a rocket scientist, but play too much KSP.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
You are right. I've changed my mind. The thing to worry about from a space tourism flight that takes 2 billionaires on a free return trajectory around the moon is the billionaires stopping off on the moon and dropping a bunch of rocks on our heads.
This is a bigger threat than video games. We need to immediately set up a gender-mixed, race-neutral (but privilege-ranked) commission to study the issue and propose controls that can be implemented to keep the threat of Space X from harming the people of earth. Oh, and also to make sure that SpaceX is totally down with the cause. And woke.
Because those racist bastards need watching.
So, a guy who plays with his wife's boobs has contempt for her? A woman grabbing her boyfriend's dick has contempt for him?
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
Fondness for the organs, contempt for the person. It really isn't that complicated.
What the heck did I just read? Why doesn't the URL include "onion" anywhere in there?
But you know you love her.
Just stand on the edge of the moon and drop the rocks off. Easy peasy.
Silly (and unfair) snark aside, not only would you need to (minimally) reach escape velocity from the moon, you'd have to change the orbit of the rock about the earth such that it wasn't nearly circular (as the moon's is.) Once you start layering on additional rockets (or solar powered ion drives or whatever) onto the rock, it's not a rock anymore.
then you can destroy the world. How you do it is not important. Large corporations have the resources to build nuclear bombs, chemical weapons, and biological weapons because they are the ones who currently do that kind of work. This is why governments need to keep tight control of these corporations.
Fondness for the organs, contempt for the person. It really isn't that complicated.
Welll I'll be, so when my wife does that to me, it's contempt, eh? We both thought it was kinda fun. I'll have to have her arrested for assault.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
Despite the President's claims, the U.S.A. already has the greatest number of the most modern aircraft carriers in the world and is quite capable of defeating the navies of Afghanistan and Switzerland simulatenously. However the nation is lagging in it's rock-dropping on the Moon and Mars capability. The defnese budget will be increased to spend 10 % on the hard rock industry.
You could easily build a rail gun that could launch pretty good size rocks off the lunar surface towards earth. Putting the infrastructure in place would be kinda pricey but once set up it would be very cheap to execute.
So if I colonize the moon and my kids go out on the surface and start throwing rocks at the earth, is it at all possible for them to enter into orbit with the earth or enter the atmosphere?
They'll have long conversations in the hallways about Sharia law, fearing being raped by Tea Party members, and the totally real country of Limpopo
>80 column hard wrapped e-mail is not a sign of intelligent
>life
from the WUSTL page:
"Words That Confuse People
asteroid – A big (>1 meter) rock or aggregation of rocks orbiting the sun
meteoroid – A small (1 meter) rock orbiting the sun"
I propose an obviously needed term:
meteroid – A precisely 1 meter rock orbiting the sun
So could one do this with off the shelf mortars rather than rockets?
https://www.google.com/search?q=mortar+for+sale
Since the magnetic driver is going to be an easy target.
Also, since we know moon dust smells like burnt gunpowder when it oxidizes, is it any use as a munition?
Moon is a Harsh Mistress is one of my favorite books...
My comments were on the technical part-- this site is news for nerds, you know. Whether you should be "afraid" is a completely different question.
I do point out that this is, so far, 480 posts (on slashdot alone) discussing details of a 140-character tweet. That's 3.4 posts for each character of the tweet, including the blank spaces at the end.
It's possible that you're overthinking it.
http://www.geoffreylandis.com
No, no no! You've got the homeopathic "theory" exactly reversed. Hitting Earth with homeopathic asteroids would make it immune from real asteroids.
My 5-yo grandson knows this! (I just asked him.) What do they teach in school these days?
Translation: this is a load of bullshit - a total non-story.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Clearly no one would ever drop rocks from the Moon, because once the Moon rotates beneath the Earth, we would just drop rocks from Earth onto their moon base. The near side of the Moon is always facing Earth, so there is no escape! And the rocks on Earth are waaaay bigger than the rocks on the Moon.
You can look at the U.S. Air Forces 2003 study on a project thor concept where 9 ton tungsten pole would hit Earth at about Mach 10 (a rather realistic order of magnitude for moon rocks flung to earth after reentry, at 3.4 km/s, it's your number essentially), for not quite 12 ton (0.012 kiloton) yield.
In short, the idea is ridiculous, a conventional bomb lobbed from a sympathetic ally on earth would be equivalent or better.
Yes, the Earth will take it and make it into a new moon. To actually hit the Earth you need to reduce the perigee from ~200k miles to 100 or so above the surface. If any random object in cislunar space but not in the moon's sphere of influence was guaranteed to impact the Earth, we'd be getting hit by a lot more asteroids (and also satellites wouldn't work very well).
Welll I'll be, so when my wife does that to me, it's contempt, eh? We both thought it was kinda fun. I'll have to have her arrested for assault.
If that's the only interaction you have with your wife, then ya, she should be arrested. Do you really think posting ridiculous scenarios is going to get your point across? A lot of us are smart enough to consider the *context* of words and actions and evaluate them therein.
Is how a plebeian stays relevant, in this day and age.
1. Announce some dumb ass shit to stir fallout
2. ??
3. PROFIT
I am reasonably sure that people in glass houses shouldn't throw stones, and if anyone on the moon started to bombard us with stones we could simply throw a few back.
https://en.wikipedia.org/wiki/...
Free speech was meant to be free for all... how can anyone grow up in a nanny state ?
Democrat Hank Johnson who thought putting 8000 US Marines on Guam would cause the island to capsize... because, you know, Democrats are all sciencey and such...
[facepalm]
There's a false internet meme that leftist politicians are smarter and more pro-science than righties. They're not. Politicians of all stripes tend to be lawyers and corruptocrats who as teenagers discovered they could get somewhere in life by exhaling while flapping thier lips and wagging their tongues and smiling and kissing babies instead of by doing something productive. That bit about pro-science Democrats is a big wad of claptrap - there are just a bunch of Democrats who see science as something they can claim to beleieve in to get support from a certain demographic. If you watch what they DO and how they VOTE, you'll notice that they only vote consistent with science when the science aligns with their idieology, and they happily reject any science that disagrees with their ideology. Politicians of allstripes are similarly anchored to things like economics and mathematics; happily invoking when it aligns with their agenda and ignoring when it does not.
No, no, no...
There won't be any need to get the products back to earth.. the aliens will just land there and pick up what they need. Geesh, you need to know who your customers are..
I don't know much about this lady, but she seems like a real winner.
You've got to feel bad for her children, though. How embarrassing to have a mother that seems to be dedicated to creating issues, controversy, and just really seems like an all-around dishonest person.
If that's the only interaction you have with your wife, then ya, she should be arrested. Do you really think posting ridiculous scenarios is going to get your point across? A lot of us are smart enough to consider the *context* of words and actions and evaluate them therein.
The irony of expressing how you are smart enough to consider the "context" of words and actions is either sad or hilarious when you take pause to notice that I indeed did change the "context: when I wrote, "or perhaps fondness".
Perhaps it isn't all that smart to claim superiority when you don't understand that someone did what you claim they didn't do.
Thanks for playing though.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
The irony of expressing how you are smart enough to consider the "context" of words and actions is either sad or hilarious when you take pause to notice that I indeed did change the "context: when I wrote, "or perhaps fondness".
It's right there for everyone to read. You made the inference that a man using his stature to "grab women by the pussy", women he doesn't even know, is analogous to you and your wife having sexual relations. You wrote this:
Welll I'll be, so when my wife does that to me, it's contempt, eh? We both thought it was kinda fun. I'll have to have her arrested for assault.
Either you are an idiot, or you are a troll. I'm guessing troll. Doesn't matter much really, we know to disregard you.
Thanks for playing though.
No problem.
Either you are an idiot, or you are a troll. I'm guessing troll. Doesn't matter much really, we know to disregard you.
Well then why don't you disregard me? If you don't understand that there is more than one possible meaning for groping, and that Donald Trump who is describing sexual assault, while I specifically offered an alternative version and after someone decided that that was also sexual assault, and I wrote the second reply. I'm not the one deciding there is one and only one definition, and that definition is sexual assault. Expand your horizons, and please ignore me. I have nothing to teach you, because you don't take telling. Ciao, me hearty!
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
I believe she has read some Robert Heinlein. And a "Huge Rocket" needed? Pshaw - Heinlein postulated rail guns. But the moon is truly a military treasure/nightmare.
This guy is mentally ill and shouldn't be allowed to run for congress.
The OP could have said anything to describe Wu, none of which have anything to do with the story except 'idiot'. Could be black, Asian, white, metero, celibate...does it even matter? There are dozens of current members of Congress who can't find Syria on a map, Democrat or Republican. Transgender doesn't mean someone is stupid. I could name thousands of straight Americans who are equally as dim. The current POTUS for one.
The moronic comments by this candidate are astonishing.it seems there are idiots on both side of the political spectrum out there..this one was hilarious.
In fairness, Trump was kidding around and bragging in a self-deprecating way. He's gross, make no mistake. But by no stretch of the imagination was he describing an actual encounter.
It is the same conversation as the classic "two brothers peeing off a bridge" joke. "Man, that water is cold." "Yeah, and it's deep too".
Nonsensical braggadocio.
Trump is bragging that he hit on the hot TV host years ago and got shot down cold... and goes on to brag about all the hot women he can get because he's rich and famous. He doesn't literally mean he walks up to hot models at the club and puts his hand between their legs to say hi. This is obvious by the context of the conversation and the laughter.
Still a gross dude. But not talking about sexual assault any more than the two mythical bros are talking about dragging their penises on the bottom of a river passing 6 feet beneath them as they urinate.
Easy enough. You'd just need to build the tracks, and you don't need to worry about zoning or the environment (nothing migrating across the track, y'know)....
> But by no stretch of the imagination was he describing an actual encounter.
I find it VERY easy to imagine that it was an actual encounter, probably many more than one.
But "locker room talk" is hardly a police confession, so you yes you have to take it with a huge grain of salt.
So, the quoted originator of this 'horror tale' is capable of reading a decades-old science fiction novel by Robert A. Heinlein. Easy to avoid; build a Space Elevator from the Lunar surface to orbit instead of a mass driver.
So, you are saying that married couples have contempt for each other? I suppose that is accurate, but it has no bearing on the conversation.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
Perhaps over the course of centuries. Things don't just fall out of the sky, you have to reduce their orbital velocity enough for them to reenter, which is an enormous amount of energy in the case of the Moon. Otherwise, it will just orbit with the Moon, or slightly inside the Moon's orbit, and likely fall back to the Moon.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
Well, what do you call someone with an X and Y chromosome and a penis who wears dresses and claims to be a feminist?
Personally, I call that a him, but it all depends.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?