What if all 6 billion of us jump off chairs at the same time? I’ll bet we could bounce the earth right out of orbit and into the sun.
Wow. I’ve spent the last two hours reading that site. Completely brilliant; thanks for posting it.
If I had this job, I’d beef up the space program (it’s not adequate now, but with the coöperation of everyone on Earth, it would be), and send some nukes out to the Oort Cloud, to be used to alter the orbits of some nice big comet-chunks. I’d then install some ion-engine type of things on those chunks, for orbital control, and use them to ferry orbital angular momentum from the Earth to Neptune, then send them back for more trips to get more. Eventually, after a great many round trips by a great many such objects, the Earth’s orbit will have decayed enough to bring it inside the Sun’s Roche limit at perihelion, which would break it up. Note that most higher life forms, ourselves included, are going to be well-done long before this, so we’ll have to make sure the automation on our cometary doom-harbingers is up to the task. Some bacteria will doubtless survive (or at least remain viable) in the Roche-chunks, but there’ll be enough of those that they’ll collide a lot, which can be expected to send most of them falling into the Sun eventually. Iron being a lot more dense than hydrogen and helium, the chunks would fall quickly to the center, where they’d be vaprorized, and the last of those pesky bacteria finally sterilized for good.
Apparently, all we need is a coffee can.
I dunno; I reckon landing the moon might be enough to recycle the entire crust of the planet, as well as searing the atmosphere with superheated steam and other gases.
If we could kick off a runaway greenhouse effect, Earth would become another Venus, and eventually everything would fry, even the bacteria in the deep rocks.
That’s what I was thinking as well, but I’m not sure we are close enough to the sun to get that kind of sustained temperature. I think if you wanted to destroy all life permanently though the sun has to somehow be involved. It’s heat, light and gravity already have such a huge impact on sustaining life, that affecting one of those relationships is likely to be the easiest way to wipe out everything.
1920s Style Death Rays… all of them… aimed at the same geographical place… full charge… BAM!
It’s the only way to be sure. 
IIRC Earth is near the inner edge of the zone where a runaway greenhouse occurs naturally, and it will likely happen in a hundred million years or so. The Sun has slowly warmed during it’s life, and that’s when the added heat will tip Earth over the edge, barring human intervention.
Cite? There is no direct correlation between incident temperature and atmosphereic temperature/greenhouse gas production, and while the proximity of proximity of Venus to the Sun certainly had a causal impact on its condition, there are other factors at work that keep the Earth at its current habitable balance. (Indeed, the average global temperature over the past 600Myr has been somewhere around 8-9°C higher than current temperatures, and the existance of photosynthetic life has a manifest impact in moderating atmospheric temperatures by binding up all the nasty hydrocarbons that polluted primordial Earth.)
While it’s true that the Sun’s surface temperature will progressively increase in incremental fashion over the next 4-5Byr, the core of the Sun will also contract slightly and will become more variable (as it balances output with internal degeneracy pressure), but reducing average total radiative output as helium waste from the initial proton-proton chain reactions starves fusion reactions in the core, until enough mass collectes to force the higher branch P-P chain reactions to occur (helium burning) and the Sun will fall off the main sequence. The increase in the Sun’s radiative temperature over the next 100Myr should be somewhere on close order of 50K (from the current ~5800K), with nominal (~1%) variation. This is probably insignificant in terms of climate effects.
If the Earth were in such a precipitous balance “near the inner edge of the zone where a runaway greenhouse occurs naturally”, then it likely would have already happened. I think it’s safe to say that we have a billion years or two before we need to worry too much about the Sun turning us into a hotbox. (Other influences, on the other hand, are potentially more troublesome.)
Stranger
Why not place the earth in shadow?
How hard can it be (assuming world-wide cooperation and resources) to orbit some shadow squares between Earth and Venus? Someone can do the math but I can’t imagine they’d have to be impossibly large (or instead of “they” just one that matches Earth’s orbit). Keep the Earth in perpetual shadow and things should cool off fairly well to the point of killing most everything.
I suppose this misses on places like mid-ocean vents where temperatures would be maintained by earth’s internal heat and life already thrives there but I assume in time those would cool off and eventually everything would freeze.
A disk large enough to mask the Sun, orbiting at .85AU (between the orbit of Venus and Earth) would have to be 220x10[sup]3[/sup] km in diameter, or a little more than 17 times the diameter of Earth. This would have a surface area of about 38x10[sup]9[/sup] km. Given concrete with a thickness of ~1m, this would mass 9.2x10[sup]19[/sup] kg; 1 Ceres or one of Jupiter’s Galilean moons should cover it.
You’ve got a problem, though: it’s free orbit is going to be of significantly shorter period than Earth; therefore, you’re either going to have to have it under constant acceleration to keep it in place, or you’re going to have to build a ring structure and spin it at the desired rate of rotation (which, in any case, will have to vary during different stages of the Earth’s orbit). You’re also going to have to figure out how to keep it on station, as we all know that a ring structure spun around a central mass is unstable. And the tension in the structure is going to be beyond teh tensile strength of any known material by many orders of magnitude.
Never mind the engineering difficulties of building and maintaining such a thing; the basic characteristics of it make it hideously unlikely. Assuming you have the ability to transport huge masses around interplanetary space and grind up major moons, you would be better off pulverizing a few small asteroids into fine dust and sprinkling it into the upper atmosphere at low velocity. This should effectively block most visible and UV light as well as a substantial portion of infrared. If you keep this up for a few years, anything that depends on photosynthesis or the products thereof will die off or go into deep hybernation, leaving you with ocean vent worms and a few simple bacteria. Salt your dust with a heavy compliment of short and medium half-life radioactive elements and you can be pretty sure of wiping out anything short of single cell bacteria.
Stranger
I thought the diameter of such an object would be smaller than the earth’s diameter? I am no mathematician (far from it) but if I hold my hand above my table and raise it towards my light source on the ceiling the shadow on the table gets bigger. That is, the further I am from the thing being shaded and the closer to the light source the bigger the shadow I cast. As such I would think that a shadow square (or disk if you prefer) could be smaller than the earth’s diameter and still cast the earth in complete shadow.
That said I assume even if we do not completely shade the earth if we manage to block a significant portion of the sun we might still achieve the same effect with a smaller, easier to build, object.
I read that, if there were a large enough amount of water vapor, methane, and carbon dioxide in the atmosphere of an earthlike planet, it could maintain an earthlike temperature even if it were as far out as Jupiter. If that’s true, I bet we could get pretty hot here, although perhaps not as hot as Venus. Anybody know if it’s true?
I don’t understand the problem here, what’s the limiting factor here?
If all nations of the world put their resources together I bet we could have a neat little set of fusion bombs in a decade. The biggest bombs we’ve made so far were either test bombs or meant to be ‘dropped’. If you’re trying to destroy the earth, you can pretty much build the bombs on site.
Remember the Tsar Bomba had a theoretical yield of 100Mt and that was just one bomb that was dropped and it was a three-stage design. They even had 50Mt ICBM warheads.
Are you saying it’s outside of our capability as a planet to produce a few tens of thousands of multi-gigaton-class multi-stage thermonuclear bombs in a decade or two? Or am I greatly underestimating the amount of energy required to completely obliterate the earth?
There are so many ways of applying enormous amounts of energy if you have no concern for human life in the first place, build a set of giant Orion-style fusion engines but thousands of times bigger than the original Orion designs - fire them all in the same direction in a timed pulse. Humanity would be dead after the first pulse, when the fuel is exhausted, if you did the math right earth will be hurling somewhere fairly quickly, if you aim right you can probably slam it right into the moon.
The OP did mention ALL of people and that implies all of our resources and no regard for human life during construction as long as it gets done.
Two problems with your analogy; one is that your light source in your example is significantly smaller than you are, and the second is that it isn’t eough to block the light source from your eyes, but you also have to block it from every other part of your body.
The Sun is about 1.4M km in diameter, and the Earth is 12,800 km. The minimum size of a global parasol, would be about 27000km in diameter, assuming that you have it “orbiting” at the Sol-Earth L1 libration point. Upon futher consideration (where I slap myself on the forehead for being an idiot), this would be the ideal place to put it, rather than in between planetary orbits; it should stay in position with minimal orientation maneuvers and not requiring any thrust or special mechanism to stay on station, plus you could give it a keel pointing toward the Earth that would keep it properly oriented (more or less) by tidal forces. This would only mass about 65x10[sup]6[/sup] tonnes (assuming a flat, 1 meter thick disk, the minimal shape), which could be supplied by a mid-sized Near Earth Object (asteroid). That puts it in the realm of just slightly absurd conjecture rather than highly improbable fantasy.
Okay, you’ve got me on board now. All we need is a few Orion-type vessels to boost the initial facilities and personnel into high orbit (if you’re going to destroy all life on Earth, you can’t bother with worrying about a very modest amount of fallout), some charged-ion or electromagnetic pulse tugs that can use some of the dust as propellent, a few hundred freefall-trained millwrights to build the underlying reinforcement frame, and a really big concrete blower. (I’m assuming that we can just vacuum cement the thing together without having to prospect for water.)
Who gets to be the evil mastermind with the orbital lair whose plan to blackmail humanity is foiled by a hard-drinking secret agent from a small European island
with cool gadgets and a beautiful but capture-prone woman in tow?
Stranger
You can block your eyes from the sun with your hand. During a solar eclipse the moon practically entirely blocks out the sun. A moon sized object right in front of the sun would not only not block it, it would probably not be even visible from here. Ergo, without using any mathematics whatsoever we can postulate that things should get bigger the closer you are to the light source in relation to the observer to provide the same “shadow”.
Now, right up next to the sun the object would have to be the size of the sun or bigger to block it effectively (just visualize it). That is bigger than earth size. The moon is smaller than earth size, but relatively speaking it’s pretty close (as compared to say, the sun) and is significantly closer than the point in question (between venetian and earth orbits, right?). Again, with no math it’s reasonable to assume an object the blocks the sun at such a distance would be significantly bigger than the moon, and most likely the earth.
The earth itself weighs about 6.6 X 10^21 gigatons. Each of your multi gigaton devices is going to have to move a lot of rock.
Looking at the problem from a less unit abusing perspective: The gravitational binding energy of the earth , (ie the energy you’d need to pick up each piece of the earth and toss it away with escape velocity) is about 2x10^32 joules.
A megaton of TNT produces about 4.184 × 10^15 joules. So you’d need the energy from a 4.8X10^16 megaton blast to completely disperse the earth. That’s 48 Million gigatons.
I don’t think even that would work. If you created a small black hole (say with the mass of a large mountain), it would just drop through your lab floor and rip through the earth like an old cartoon anvil dropped off a building. It would then settle in the center of the Earth and swallow up everything inside it’s event horizon. At worst I think we might end up with an Earth with a hollow center. The total mass wouldn’t change so it wouldn’t affect our orbit.