Search the archive.

The creation of black holes at the Large Hadron Collider is very unlikely. However, some theories suggest that the formation of tiny 'quantum' black holes may be possible. The observation of such an event would be thrilling in terms of our understanding of the Universe; it would also be perfectly safe. Two types of black hole Black holes form in space when certain stars, much larger than our Sun, collapse on themselves at the end of their lives. They concentrate a very large amount of matter in a very small space. They are so dense that the gravity they exert is such that not even light can travel out of them. Speculations about black holes at the LHC refer to particles produced in the collisions of pairs of protons. These are microscopic - or quantum - black holes. Scientists are not at all sure that quantum black holes exist. Nature's experiment A computer-generated image showing the detection of a microscopic black hole A simulation of a quantum black hole detected by the ATLAS experiment, before it decays via a process known as Hawking radiation. » see larger version on the CERN Document Server The physical part of the LHC experiments - colliding particles - happens in nature all the time. We know, for example, that the Earth is constantly bombarded by cosmic rays: when cosmic rays hit the atmosphere, particles are colliding with one another in much the same way as in the collisions planned at the LHC. Just as we know that the Earth is safe under the natural bombardment from cosmic rays, so we know that recreating these collisions poses no threat to the Earth. Nature’s collisions also reach much higher energies than those at the LHC. What if collisions at the LHC produced a black hole? The creation of a quantum black hole at the LHC would be very surprising, but very exciting indeed. It would allow physicists to learn about nature’s most elusive force – gravity. Remember: particle collisions happen all the time in nature, and we're all still here. If you would like to read up more on the safety of the LHC, there is more information here. What would be the significance of the creation of a black hole at the LHC? The creation of a black hole at the LHC would confirm theories that our universe is not 4 dimensional (3 space plus 1 time dimensions), but indeed hosts other dimensions. It would be quite a spectacular philosophical outcome! In the same way that the theory of relativity or of quantum mechanics revolutionized our way of thinking, discovering the existence of extra dimensions would be a major new milestone in our understanding of the Universe. There is no obvious application for knowing this. Many people will start speculating about using these extra dimensions for space and time travel, or as a source of clean energy, and who knows what else. It is rather tempting to compare it to the discovery of magnetism by the Phoenicians who could not foresee that electricity and magnetism would completely reshape modern life...

Another way of revealing extra dimensions would be through the production of “microscopic black holes”. What exactly we would detect would depend on the number of extra dimensions, the mass of the black hole, the size of the dimensions and the energy at which the black hole occurs. If micro black holes do appear in the collisions created by the LHC, they would disintegrate rapidly, in around 10-27 seconds. They would decay into Standard Model or supersymmetric particles, creating events containing an exceptional number of tracks in our detectors, which we would easily spot. Finding more on any of these subjects would open the door to yet unknown possibilities.

One of the places that personifies all of this is the Large Hadron Collider (LHC) at CERN, where in the next few months, we’ll begin colliding protons at the highest energies ever achieved in a particle accelerator. A few years ago, we broke the old record — 2 TeV (tera-electron-Volts, or 10^12 eV), which was set at Fermilab — by accelerating each particle up to 3.5 TeV and smashing them into one another, achieving 7 TeV of total energy.//// This discovery enabled us to not only create huge numbers of a great many elusive, fundamental particles (like the top quark, as well as the W-and-Z bosons), but enabled us to discover a brand new fundamental particle and last undiscovered particle in the standard model: the Higgs boson. //// Later this year, upgrades to the LHC will enable us to reach somewhere between (depending on whom you ask) 13-and-14 TeV of total energy. If we’re really lucky, the sheer number of collisions at these tremendous energies, combined with the incredible detectors we have in place, may allow us to create and discover never-before-seen particles in this laboratory. //// Of course, that hasn’t stopped the usual suspects from making incredible (and completely non-credible) claims, such as: //// , , and That may . While the first two are just bad science reporting, the third one is a common fear that’s reared its ugly head time and time again, and has no basis in reality. //// So what’s the big idea, and how do we know it’s wrong? Let’s find out. //// There are a number of theories that predict the existence of extra dimensions. Not merely the three spatial and one time dimension we know to be present in our four-dimensional spacetime, but at least one additional spatial dimension that exists in our Universe. While we can’t quite access those dimensions at the energies we’ve probed, it’s conceivable that at scales that are smaller than those we’ve examined — which corresponds to higher energies — these extra dimensions exist. //// And if these extra dimensions exist, one theoretical possibility is that it might be possible to create tiny, miniature, microscopic black holes! //// If we could do this, this would be an incredible feat of technology, of science, and an amazing piece of evidence that would change our understanding of the Universe forever. Of course, however, you say the words “black holes” and people immediately get this catastrophic picture of something sucking in all sorts of matter, progressively eating the protons, neutrons and electrons that make up our world, and eventually destroying the entire thing. //// This is not possible. In fact, there are three reasons we know this is not possible. Let’s go over them one at a time. //// 1.) If these miniature black holes exist, the Earth has been getting hit by them for billions of years, and it’s still here. //// Sure, we’ve never created particles of this energy in a laboratory setting before. But at the very highest of energies — energies more than a hundred million (100,000,000) times greater than what we create at the LHC — particles smack into Earth constantly: the great cosmic rays that bombard us from all directions in space. //// These black holes, if they exist, would have been bombarding Earth (and all the planets) for the entire history of our Solar System, as well as the Sun, and there is absolutely no evidence that any body in our Solar System ever became a black hole or got eaten by one. //// But maybe, you’ll object, these objects were moving too quickly, and so they’ll simply pass through the Earth, eating too little matter to remain inside, and pass through to intergalactic space. Well, if that’s your objection, perhaps this second reason-why-this-is-impossible will help you out. //// 2.) If you do create a miniature black hole, they will decay, via Hawking Radiation, on ridiculously small timescales. //// If there are extra dimensions, it is conceivable that they could be of a specific type allowing the (again, very rare, but plausible) formation of a microscopic black hole. This black hole will have, at most, a mass equal to the energy of the proton-proton collision, or up to 13-to-14 TeV. That corresponds, via E=mc^2, to a mass of just 5 x 10^-20 grams, and most likely less. //// But, even if you have extra dimensions of the right scale, and of the right type,and you make this black hole, you still have a problem: it’s unstable. Due to the laws of quantum mechanics, this black hole is going to decay by a process known as . For a black hole of mass 5 x 10^-20 grams, the decay time in three dimensions would be about 10^-83 seconds, which is not even enough time For physics to be meaningful, we need a time of about 10^-43 seconds or longer. Translated into black hole mass, we’d need it to be at least 0.00002 grams to have even a chance of existing. //// In four dimensions, however, especially if the “extra” one is large, the decay time goes all the way up to 10^-23 seconds. Oh, joy. To overcome the expected decay of this miniature black hole, you have to throw out the known laws of physics. These laws are so well-established that it’s inconceivable that they’d be wrong — it would be like waking up tomorrow and seeing the Sun rise in the West. //// But, for argument’s sake, let’s assume there are some new laws of physics that we haven’t conceived of yet that could make these black holes stable. So you make a black hole — a tiny one — at rest with respect to Earth’s center, and it doesn’t decay. Could it eat the Earth? And if so, how fast would that happen? This brings us to our third and final objection, and remember: we’ve already allowed you to throw out the known laws of physics twice to get to this point. //// 3.) You can compute the rate at which a black hole eats matter, and it’s not even close to being as small as the lifetime of our planet. //// We like to think of black holes as “sucking” in matter, but the truth of the matter is, they can only interact with it gravitationally. At a mass of ~5 x 10^-20 grams, that gravitational force it exerts is incredibly weak: all it can manage to do is pass into the Earth’s center and out again, hoping for a collision with an elementary particle as it does so. While the black hole’s cross-section is tiny, the cross-section of a proton (or neutron) is pretty large, and so we can assume — for the sake of argument — that every time the black hole strikes a proton or neutron, it absorbs it. //// Assuming it eats every proton, neutron, or electron that it comes in contact with — and also taking into account its gravity, to see what it attracts — it will eat about 66,000 protons and neutrons per second. Of course, 66,000 protons-and-neutrons is a tiny amount in terms of mass: 1.1 x 10^-25 grams. That rate-of-growth will be constant until the black hole becomes quite large; only at about one billion metric tonnes will the black hole will start to grow faster than this rate, as it takes that long for its cross-section to increase. Capturing 66,000 nucleons per second, how long will it take to get the black hole up to even one kilogram? Three trillion years, which is much longer than the lifetime of the Sun or even the age of the Universe. //// So even if you make a black hole, and even if the laws of physics that we know are wrong and it lives forever, it is still harmless. No matter how many of the laws of physics you throw out, revise or tweak, the Earth will still be okay. //// So take heart! We’re all set to probe the frontiers of physics, to increase our knowledge and understanding of the Universe, and to do it in a totally safe way. Any fears you may have concerning our planet getting eaten by a black hole are completely irrational, and now — armed with the scientific knowledge of why — you can rest easy. //// The world is safe. At least, from physics.

Has Anyone Created a Black Hole on Earth? Credit: Jennifer Lamberth/EyeEm/Getty Images In the popular imagination, black holes are voracious monstrosities gulping down anything in their vicinity. That is why there are occasional worries that physicists might accidentally or intentionally create one, perhaps inside a particle accelerator such as the Large Hadron Collider (LHC) at CERN near Geneva. Would such a dark behemoth swallow up Earth itself? Not quite. No one has ever created a black hole on our planet before. But even if someone did, it likely wouldn’t pose a huge threat. Real-world black holes are only scary in the sense that if you get too close to one, you won’t be able to escape. But even if someone generated a black hole in a laboratory on Earth, the limits of human technology would prevent us from whipping up anything particularly dangerous. “It would likely be so low-mass that its gravitational influence would be relatively small,” says Eliot Quataert, a theoretical astrophysicist at Princeton University. “It wouldn’t actually gobble up that much matter.” In fact, the possibility of creating a black hole in a lab is a goal that scientists are actively pursuing—one that could allow researchers to answer many fundamental questions about quantum mechanics and the nature of gravity. ADVERTISEMENT A black hole typically forms when a star much more massive than our sun dies. While the outer layers of such a star explode outward in a spectacular supernova, its core crumples inward, pressing down toward its central point with so much power that no known force in the universe can stop it. This results in a subatomic spot of unimaginable mass and density whose gravity is so strong that even something traveling at the speed of light couldn’t move fast enough to escape its clutches. These kinds of black holes are common throughout the universe. Of course, as long as something doesn’t get too near a black hole, it’s safe. Only within a spherical boundary surrounding the black hole known as the event horizon would a person or object get pulled inexorably inward. Enormous black holes have a big event horizon—with a diameter of millions of kilometers—whereas smaller ones have more minute event horizons, extending just tens of kilometers across. If you could make a black hole in a lab that weighed only half a kilogram, it would have an event horizon one trillion times smaller than a proton. Fears about the LHC creating a black hole originated with the fact that in Einstein’s special theory of relativity, mass (m) and energy (E) are interchangeable—hence the famous equation E = mc2, where “c” is the speed of light. Because a supercollider slams together protons at unbelievable velocities (nearing the speed of light) and energies, all sorts of strange and exotic particles can pop out, potentially including a black hole. But creating a black hole with even a microscopic event horizon would require billions of times more energy than the LHC is able to produce. And even if it could produce such a black hole, that object would quickly lose energy and dissipate in the blink of an eye. Before the facility turned on in 2008, some researchers had postulated that, if the fabric of spacetime had extra dimensions such as those hypothesized under string theory—a possible way to combine quantum physics and gravity into a single theory—a black hole could appear. That’s because in our four-dimensional universe (with three dimensions of space and one of time), gravity is too weak to pound matter into a black hole. If other dimensions exist, however, gravity may not be the weakling it seems to us, because some of its force could be leaking into these other strange dimensions. In such a universe, a black hole appearing inside an atom smasher becomes much more feasible, potentially revealing insights into the very nature of gravity. This discovery would have been “among the most weird and surprising physics you could see in the LHC,” says Juan Maldacena, a theoretical physicist at the Institute for Advanced Study in Princeton, N.J. ADVERTISEMENT The idea was picked up by the media, producing a large splash. A German chemist even filed a lawsuit against CERN in the European Court of Human Rights. A special committee of physicists had already started looking into the matter in 2003, concluding that because particles from space crash into the atmosphere with energies far greater than those at the supercollider without producing black holes, the possibility appeared to be remote. The committee’s report was reviewed and reissued in 2008 with more information to calm public fears. To date, no black holes have been seen at the LHC. Confirming the predictions of string theory “would have been nice,” Maldacena says, “but it’s not what happened.” More recently, a team announced that it had formed a simulation of a baby wormhole—a type of bridge through reality created from two black holes—using a quantum computer. Though the result was covered widely in the press, it wasn’t exactly the breakthrough that many imagined. newsletter promo Sign up for Scientific American’s free newsletters. Sign Up “What has been created is more like some weird quantum mechanical property of matter that has mathematical properties related to wormholes,” Quataert says. “It’s more of a conceptual connection than a literal connection.” Nevertheless, the research is promising, Maldacena says, and more powerful quantum computers in the future could someday generate objects that simulate black holes using Albert Einstein’s equations, allowing physicists to study their behavior in detail.

--timescale is super distant – 10^8 years – making prediction impossible and making it tactically useless

--indicts Torres

There's this preprint by Krauss and Dent getting a lot of discussion that suggests, in a remark at the very end that was of course destined to get a writeup in New Scientist, that our astronomical measurements of dark energy may destroy the universe for arcane quantum reasons. I think it's totally wrong.

The paper starts with an oddity that I learned about back in college, that a system that decays exponentially will (if left completely undisturbed) eventually pass to a realm in which it decays more slowly, via power law. This is generally practically unobservable, but they suggest it may have cosmological relevance if we live in an unstable false vacuum: it interacts in an interesting way with the cosmic inflation induced by dark energy, and this effect could be the only thing keeping us around. But watch out: since observing the system "resets the clock" (the famous quantum Zeno effect), we may have just returned to the exponential realm and thus sealed our doom by measuring the dark energy through supernova observations! Eat of the fruit of the tree of knowledge and you shall die.

At the other end of the philosophical spectrum, I met with Don Page, a physicist and evangelical Christian at the University of Alberta in Canada, noted for his early collaboration with Stephen Hawking on the nature of black holes. To Page, the salient point is that God created the Universe ex nihilo – from absolutely nothing. The kind of cosmogenesis envisioned by Linde, in contrast, would require physicists to cook up their cosmos in a highly technical laboratory, using a far more powerful cousin of the Large Hadron Collider near Geneva. It would also require a seed particle called a ‘monopole’ (which is hypothesized to exist by some models of physics, but has yet to be found).

The idea goes that if we could impart enough energy to a monopole, it will start to inflate. Rather than growing in size within our Universe, the expanding monopole would bend spacetime within the accelerator to create a tiny wormhole tunnel leading to a separate region of space. From within our lab we would see only the mouth of the wormhole; it would appear to us as a mini black hole, so small as to be utterly harmless. But if we could travel into that wormhole, we would pass through a gateway into a rapidly expanding baby universe that we had created. (A video illustrating this process provides some further details.)

This is a very important question, I believe it is imperative to answer and clarify this concept to general public, since a lot of science fiction and pseudo-science has got attached to it, and some fraudulent individuals are trying to coax people into thinking that it can generate useful energy or work. Zero-point energy has become like an urban legend, which though true in its basic scientific roots, has no useful potential in our actual real-world life in terms of fulfilling our energy needs. It is similar to the wrong idea of using ordinary water at normal temperature and pressure to propel turbines or engines and drive our vehicles. The laws of thermodynamics do not permit these. As I have said many times before, when Laws of Thermodynamics do not permit something, then that thing cannot have a physical existence, as far as our knowledge of physics is concerned.

First of all, let’s look at what zero-point energy is. Zero-point energy is a non-vanishing energy which is there even when a particle or system has reached its ground state. Its magnitude is

We are doomed. Our best efforts to reproduce, to conserve, protect and survive will, in the end, come to nought. We could sort out climate change, dispose of our nuclear arsenals, ban research into killer AIs, and still the end would come, as surely as night follows day.

The problem is physics itself. Our home – our planet, our Solar System and indeed our entire Universe – has a finite lifespan. All that is will be destroyed, either in fire or, as observations suggest now seems more likely, in a lingering, depressing ‘heat death’. The stars will all go out, and the expanding cosmos will be no more than a colossal, black and freezing void in which nothing of interest ever happens again. The laws of nature insist upon it.

There is also the possibility that a Type II or Type III civilization might be able to reach the fabled Planck energy with their machines (10^19 billion electron volts). This is energy is a quadrillion times larger than our most powerful atom smasher. This energy, as fantastic as it may seem, is (by definition) within the range of a Type II or III civilization. The Planck energy only occurs at the center of black holes and the instant of the Big Bang. But with recent advances in quantum gravity and superstring theory, there is renewed interest among physicists about energies so vast that quantum effects rip apart the fabric of space and time. Although it is by no means certain that quantum physics allows for stable wormholes, this raises the remote possibility that a sufficiently advanced civilizations may be able to move via holes in space, like Alice's Looking Glass. And if these civilizations can successfully navigate through stable wormholes, then attaining a specific impulse of a million seconds is no longer a problem. They merely take a short-cut through the galaxy. This would greatly cut down the transition between a Type II and Type III civilization. Second, the ability to tear holes in space and time may come in handy one day. Astronomers, analyzing light from distant supernovas, have concluded recently that the universe may be accelerating, rather than slowing down. If this is true, there may be an anti-gravity force (perhaps Einstein's cosmological constant) which is counteracting the gravitational attraction of distant galaxies. But this also means that the universe might expand forever in a Big Chill, until temperatures approach near-absolute zero. Several papers have recently laid out what such a dismal universe may look like. It will be a pitiful sight: any civilization which survives will be desperately huddled next to the dying embers of fading neutron stars and black holes. All intelligent life must die when the universe dies.

We have reached a turning point in society. According to renowned , the next 100 years of science will determine whether we perish or thrive. Will we remain a Type 0 civilization, or will we advance and make our way into the stars? Experts assert that, as a civilization grows larger and becomes more advanced, its energy demands will increase rapidly due to its population growth and the energy requirements of its various machines. With this in mind, was developed as a way of measuring a civilization’s technological advancement based upon how much usable energy it has at its disposal. MEET THE KARDASHEV SCALE The scale was originally designed in 1964 by the Russian astrophysicist (who was looking for signs of extraterrestrial life within cosmic signals). It has 3 base classes, each with an energy disposal level: Type I (10¹⁶W), Type II (10²⁶W), and Type III (10³⁶W). Other astronomers have extended the scale to Type IV (10⁴⁶W) and Type V (the energy available to this kind of civilization would equal that of all energy available in not just our universe, but in all universes and in all time-lines). These additions consider both energy access as well as the amount of knowledge the civilizations have access to. First, it is important to note that the human race is not even on this scale yet. Since we still sustain our energy needs from dead plants and animals, here on Earth, we are a lowly Type 0 civilization (and we have a LONG way to go before being promoted to a type I civilization). Kaku tends to believe that, all things taken into consideration, time. But what does each of these categories actually stand for in literal terms? A is a given to species who have been able to harness all the energy that is available from a neighboring star, gathering and storing it to meet the energy demands of a growing population. This means that we would need to boost our current energy production over 100,000 times to reach this status. However, being able to harness all Earth’s energy would also mean that we could have control over all natural forces. Human beings could control volcanoes, the weather, and even earthquakes! (At least, that is the idea.) These kinds of feats are hard to believe, but compared to the advances that may still be to come, these are just basic and primitive levels of control (it’s absolutely nothing compared to the capabilities of societies with higher rankings). The next step up – a – can harness the power of their entire star (not merely transforming starlight into energy, but controlling the star). Several methods for this have been proposed. The most popular of which is the This device, if you want to call it that, would encompass every single inch of the star, gathering most (if not all) of its energy output and transferring it to a planet for later use. Alternatively, if fusion power (the mechanism that powers stars) had been mastered by the race, a reactor on a truly immense scale could be used to satisfy their needs. Nearby gas giants can be utilized for their hydrogen, slowly drained of life by an orbiting reactor. What would this much energy mean for a species? Well, nothing known to science could wipe out a Type II civilization. Take, for instance, if humans survived long enough to reach this status, and a moon sized object entered our solar system on a collision course with our little blue planet–we’d have the ability to vaporize it out of existence. Or if we had time, we could move our planet out of the way, completely dodging it. But let’s say we didn’t want to move Earth… are there any other options? Well yes, because we’d have the capability to move Jupiter, or another planet of our choice, into the way – pretty cool, right? So we’ve gone from having control over a planet, to a star, which has resulted in us to essentially make our civilization immune to extinction. But now, onto Type III, where a species then becomes galactic traversers with knowledge of everything having to do with energy, resulting in them becoming a master race. In terms of humans, hundreds of thousands of years of evolution – both biological and mechanical – may result in the inhabitants of this type III civilization being incredibly different from the human race as we know it. These may be cyborgs (or , beings both biological and robotic), with the descendants of regular humans being a sub-species among the now-highly advanced society. These wholly biological humans would likely be seen as being disabled, inferior, or unevolved by their cybernetic counterparts. At this stage, we would have developed colonies of robots that are capable of ‘self replication’; their population may increase into the millions as they spread out across the galaxy, colonizing star after star. And these being might build Dyson Spheres to encapsulate each one, creating a huge network that would carry energy back to the home planet. But stretching over the galaxy in such a manner would face several problems; namely, the species would be constrained by the laws of physics. Particularly, light-speed travel. That is, unless they develop , or use that immaculate energy cache to master wormhole teleportation (two things that remain theoretical for the time being), they can only get so far. Kardashev believed a was ‘too’ advanced and didn’t go beyond Type III on his scale. He thought that, surely, this would be the extent of any species’ ability. Many think so, but a few believe there is a further level that could be achieved. (I mean, surely there is a limit?) Type IV civilizations would almost be able to harness the energy content of the entire universe and with that, they could traverse the accelerating expansion of space (furthermore, advance races of these species ). To previous methods of generating energy, these kinds of feats are considered impossible. A Type IV civilization would need to tap into energy sources unknown to us using strange, or currently unknown, laws of physics. Type V. Yes, Type V might just be the next possible advancement to such a civilization. Here beings would be like gods, having the knowledge to manipulate the universe as they please. Now, as I said, humans are a very, very long way from ever reaching anything like this. But it’s not to say that it cannot be achieved as long as we take care of Earth and each other. To do so, the first step is to preserve our tiny home, extinguish war, and continue to support scientific advances and discoveries.

Stephen Hawking’s recent remarks regarding the possibility that our descendants might one day destroy the universe by disrupting the Higgs field with a larger-than-Earth supercollider has gotten people thinking: is there anything we could do now that would destroy the universe?

The answer to that question is, by all appearances, a pretty clear no. Here are two good reasons why:

But claiming that there should not be any more people does not imply that the population should be zero. As already stated: life-extension technologies could enable people to live indefinitely long lives – that is, to attain what I call “functional immortality”, whereby one lives until she either succumbs to injury, commits suicide, or perishes due to the heat death of the universe.8 This gestures the “dual policy” at the heart of no-extinction anti-natalism: first, we should stop procreating entirely (anti-natalism), and second, we should develop safe and effective life-extension technologies (pro-immortalism). This should appeal to Benatar himself given his anti-Epicurean view that death is (often) bad and, as such, one ought to (typically) avoid it. The reason is that, when evaluating an outcome, any harm at all “will be decisive”. Since “we (usually) have an interest in continuing to exist…death may be thought of as a harm, even though coming into existence is also a harm” (Benatar 2006, 213). This links to an important distinction between “lives worth starting” and “lives worth continuing”. Although life is much worse than most of us realise, many lives are not so bad as to warrant suicide. Thus, they are worth continuing even though they were not worth starting, much like a movie that is worth finishing but not having started. (If only you had known the movie was bad, you would have stayed home rather than venturing out to the theatre.)

But just as there are human lives worth continuing, there are arguments for why human existence is worth continuing, even if it would have been better for our evolutionary lineage never to have been. The strongest argument against human extinction, if sound, comes from total utilitarianism. The first to articulate this idea was Henry Sidgwick [1874] 1962, although more recent versions proceed by calculating how many people could come to populate Earth or our future light cone, with some claiming that up to 10^46 “human lifetimes” could exist per century within our galactic supercluster (Ćirković 2002). Since people are the substrate or “containers” of well-being (or value), the more people there are with net positive amounts of well-being, the better things will go from the “point of view of the universe”. But creating new lives is incompatible with anti-natalism, so this line of argumentation is a non-starter in the present context. There is, however, an alternative approach that focuses not on the total number of people but on the quality of their lives – rather than merely “lives not so bad as to warrant suicide”, there could exist future life conditions that are extremely good and hence very much worth continuing.

Until recent years the evaluation of nuclear warfare effects has been chiefly in terms of the direct impacts of the blast, heat and local radioactive fallout as they destroy humans, artifacts and social structure. Much of the public debate over the notions of a winnable, limited nuclear war and of survival thereafter has focused on the enormity of demands placed upon medical assistance for those people who live through the initial blast, the rationale or absurdity of plans to carry out massive evacuations as a means of deterring or mitigating the consequences of nuclear attacks, and the complexity of reconstruction.

Now, greater attention is turning toward the environmental consequences of nuclear detonations. This is basically because of increasing recognition that regardless of the immediate impact on lives, health, buildings, public facilities and the means of production, nuclear explosions might drastically alter if not, perhaps, fatally impair the life support systems of the globe. The vision of increasing through civil defense the number of survivors from direct impacts becomes morbidly whimsical if the survivors are in environments no longer capable of providing essential water and food.

And what sorts of quarters awaited those who staggered down the stairs? Only a handful were relatively posh; Chase Manhattan Bank, for one, dropped $49,000 on “compressed” wheat biscuits in banana and chocolate flavors to stock its five-story shelter. But most citizens would find only dank, low-ceilinged basements equipped with the barest necessities: bedding, drums of potable water, medical kits and government-issue wheat crackers. And while Uncle Sam thoughtfully provided toilet paper, the toilets themselves were harder to come by. A handy tip from a government booklet advised: “Make a commode by cutting the seat out of a chair and placing the pail under it.” It’s little wonder that the medical kits also included phenobarbital to chill everybody out.

Perhaps not surprisingly, the trouble with such crude accommodations became obvious almost immediately. Mere months into the program, reports emerged of leaking water drums and shelters that had never received any supplies. In a New York Times story in June of 1963, a Harlem woman asked, “Who’d want to go down there?” referring to the fetid tenement cellar meant to serve as her shelter space. The “rats are as big as dogs,” she said. “If fallout came, I’d just run.” In fact, the untenability of the shelters was public knowledge before they had even opened. A November 1961 story on the front page of The Washington Post bemoaned that most of the designated shelters would be little more than “cold, unpleasant cellar space, with bad ventilation and even worse sanitation.”

https://www.reddit.com/r/Foodforthought/comments/pidv2e/the_ability_to_stir_new_life_into_being_all/

It's an interesting idea, but it avoids discussing in any detail how this "protospermia" might work. Intuitively it seems like a nearly impossible task - certainly one we have nowhere near the required level of understanding to execute.

Island populations are very vulnerable to extinctions for a couple of reasons. They tend to have been isolated. One of the things we’re doing is removing the barriers that used to keep island species isolated. New Zealand had no terrestrial mammals. Species that had evolved in the absence of such predators were incredibly vulnerable. A staggering number of bird species have already been lost on New Zealand, and a lot of those that remain are in deep trouble. So, places that have been isolated for a long time. Those are very vulnerable. Species that have a very restricted range, that exist only in one spot in the world, those tend to be extremely vulnerable. They have nowhere to go and if their habitat is destroyed, say, then they’re gone.

Here is what we know: First, nuclear weapons are capable of causing human extinction, along with the extinction of many other species. Second, nine countries continue to rely upon these weapons for their so-called “national security.” Third, these nine countries are continuing to modernize their nuclear arsenals and failing to fulfill their legal and moral obligations to achieve a Nuclear Zero world – one in which human extinction by means of nuclear weapons is not a possibility because there are no nuclear weapons. Given these knowable facts, we might ask: What kind of “national security” is it to rely upon weapons capable of causing human extinction? Or, to put it another way: How can any nation be secure when nuclear weapons threaten all humanity? Certainly, it requires massive amounts of denial to remain apathetic to the extinction dangers posed by nuclear weapons. There appears to be a kind of mass insanity – a detachment from reality. Such detachment seems possible only in societies that have made themselves subservient to the nuclear “experts” and officials who have become the high priests of nuclear strategy. Whole societies have developed a gambler’s addiction to living at the edge of the precipice of nuclear annihilation. Remember Jonathan Schell’s insight: “We prepare for our extinction in order to assure our survival.” Of course, it is nonsensical to prepare for extinction to assure survival. Just as to achieve peace, we must prepare for peace, not war, we must be assuring our survival not by preparing for our extinction, but by ridding the world of the weapons that make this threat a possibility. We must, as Albert Einstein warned, change our “modes of thinking” or face “unparalleled catastrophe.”[iv] The Victims There have been many victims of the Nuclear Age, starting with those who died and those who survived the US atomic bombings of Hiroshima and Nagasaki. This year marks the 70th anniversary of those bombings. The survivors of those bombings are growing older and more anxious to see their fervent wish, the abolition of nuclear weapons, realized. In addition to the victims in the atomic-bombed cities, there have been many other victims of nuclear weapons. These include the people at the nuclear test sites and those downwind from them. They have suffered cancers, leukemia and other illnesses. The effects of the radiation from the nuclear tests have also affected subsequent generations, causing stillbirths and many forms of birth defects. The Marshall Islanders were one group of nuclear victims. They lived on pristine Pacific islands, living simple lives close to the ocean waters that provided their bounty. But between 1946 and 1958 the US conducted 67 nuclear tests in the Marshall Islands. The tests had the equivalent power of 1.6 Hiroshima bombs being exploded daily for 12 years. Some of the islands and atolls in the Marshall Islands became too radioactive to inhabit. The people of the Republic of the Marshall Islands (RMI), who became guinea pigs for the US to study, continue to suffer. They have never received fair or adequate compensation for their injuries resulting from the US nuclear testing program.

Genetic diversity generally underpins population resilience and persistence. Reductions in population size and absence of gene flow can lead to reductions in genetic diversity, reproductive fitness, and a limited ability to adapt to environmental change increasing the risk of extinction. Island populations are typically small and isolated, and as a result, inbreeding and reduced genetic diversity elevate their extinction risk. Two island populations of the platypus, Ornithorhynchus anatinus, exist; a naturally occurring population on King Island in Bass Strait and a recently introduced population on Kangaroo Island off the coast of South Australia. Here we assessed the genetic diversity within these two island populations and contrasted these patterns with genetic diversity estimates in areas from which the populations are likely to have been founded. On Kangaroo Island, we also modeled live capture data to determine estimates of population size. Levels of genetic diversity in King Island platypuses are perilously low, with eight of 13 microsatellite loci fixed, likely reflecting their small population size and prolonged isolation. Estimates of heterozygosity detected by microsatellites (HE= 0.032) are among the lowest level of genetic diversity recorded by this method in a naturally outbreeding vertebrate population. In contrast, estimates of genetic diversity on Kangaroo Island are somewhat higher. However, estimates of small population size and the limited founders combined with genetic isolation are likely to lead to further losses of genetic diversity through time for the Kangaroo Island platypus population. Implications for the future of these and similarly isolated or genetically depauperate populations are discussed. Genetic diversity has been identified as an important factor influencing a population's long-term potential for survival (Bouzat 2010). The contribution of genetic diversity has been recognized in numerous aspects of population persistence, and is critical for long-term fitness and adaptation [see Frankham (2005) for a review]. A loss of genetic diversity has been shown to affect individual fitness with decreased sperm quality (Hedrick and Fredrickson 2010), reduced litter size (Hedrick and Fredrickson 2010), increased juvenile mortality (Ralls et al. 1988), and increased susceptibility to disease and parasites (Coltman et al. 1999). Accordingly, populations lacking genetic diversity often exhibit an increased rate of extinction (Markert et al. 2010). Inbreeding, genetic drift, restricted gene flow, and small population size all contribute to a reduction in genetic diversity. Fragmented and threatened populations are typically exposed to these conditions, which is likely to increase their risk of extinction (Saccheri et al. 1998; Madsen et al. 1999; Frankham et al. 2010). Island populations are often isolated and small in size, and therefore experience increased levels of inbreeding and a greater impact of genetic drift. As a result, these populations generally have lower levels of genetic diversity and fitness than counterparts found in mainland populations. For example, the black-footed rock-wallabies of Barrow Island, Western Australia, have extremely low levels of genetic diversity (HE= 0.053), which has led to this population suffering inbreeding depression: females experience reduced fecundity and individuals exhibit increased levels of fluctuating asymmetry (Eldridge et al. 1999). These findings are not atypical with island populations frequently identified as having reduced genetic diversity, increased levels of inbreeding, and therefore a higher extinction risk (Frankham 1997).

Dr. Tom Chalko, MSC, PhD, head of Australia's physics, 2003 (March 3, Scientific Engineering Research, "Can a Neutron Bomb accelerate Global Volcanic Activity?", http://sci-e-research.com/neutron_bomb.html)

Consequences of using modern nuclear weapons can be far more serious than previously imagined. These consequences relate to the fact that most of the heat generated in the planetary interior is a result of nuclear decay. Over the last few decades, all superpowers have been developing so-called "". These bombs are designed to emit intensive neutron radiation while creating relatively little local mechanical damage. Military are very keen to use neutron bombs in combat, because lethal neutron radiation can peneterate even the largest and deepest bunkers. However, the military seem to ignore the fact that a neutron radiation is capable to reach significant depths in the planetary interior. In the process of passing through the planet and losing its intensity, a neutron beam stimulates nuclei of radioactive isotopes naturally present inside the planet to disintegrate. This disintegration in turn, generates more neutron and other radiation. The entire process causes increased nuclear heat generation in the planetary interior, far greater than the initial energy of the bomb. It typically takes many days or even weeks for this extra heat to conduct/convect to the surface of the planet and cause increased seismic/volcanic activity. Due to this variable delay, nuclear tests are not currently associated with seismic/volcanic activity, simply because it is believed that there is no theoretical basis for such an association. Perhaps you heard that after every major series of nuclear test there is always a period of increased seismic activity in some part of the world. This observable fact CANNOT be explained by direct energy of the explosion. The mechanism of neutron radiation accelerating decay of radioactive isotopes in the planetary interior, however, is a VERY PLAUSIBLE and realistic explanation. The process of accelerating volcanic activity is nuclear in essence. Accelerated decay of unstable radioactive isotopes already present in the planetary interior provides the necessary energy. The TRUE danger of modern nuclear weaponry is that their neutron radiation is capable to induce global overheating of the planetary interior, global volcanic activity and, in extreme circumstances, may even cause the entire planet to explode.