jrphilps

I think I understand. Line of sight (LOS) is limited by the observers height, so a gun emplacement located high off the ground would have a longer LOS, and would hence be able to cover more ground. So I guess 3600 ion cannons is the minimum amount, unless you mount them on sky scrapers or something

Whoa, I didn't think it would be that many. That is quite a feat of engineering.

Hey, you're a math literate guy, I was wondering whether you could help me with a question. If we were to go with the star wars model and emplace gun batterys on the planets surface, how many would you need to completely cover the sky arc of an earth sized planet?

Thats definitely another option. By using solar panels to collect huge amounts of energy from the local star, you can power an array of directed energy weapons which could wipe out whole fleets. Although the light speed delay is an issue. Another question for this thread: If you were to emplace gun batterys on the planets surface, how many would you need to completely cover the sky arc of an earth sized planet?

If the invading ships have excellent armor, then debris might not be sufficient. This also holds true for ships with excellent sensors: If they detect the debris, they can maneuver out of the way or vaporise it with their weapons. At a minimum, you would need asteroids with some means of actively going after intruding ships (maybe a thruster to steer itself, or a proximity fused mine). Orbital debris would be only a stop gap.

In some works of science fiction, a space farring empire will need to fortify their planetary colonys from assaults launched by rival factions, privateers, terrorists, and the occasional alien scum. One fine example of this is the galactic empire from star wars. Their fortification schemas had a layered pattern to prevent intrusions into the planet. The first line of defense was battle stations located at lagrange points, where patrols could be conveniently launched from. The second was a huge number of surface based ion cannons to shoot down any craft which entered orbit. The third was dozens of garrison bases with enough troops, tanks, and aircraft to repel an invasion force. Of course, all this brings up an interesting question. When the empire needed to conquer a world that was not under their direct control (maybe it was part of the hutt clan, or the corporate sector authority) and rapidly fortify it against counter-attack, would this schema still be appropriate? Could they get all the infrastructure into place quickly? Would fortifying the planet be more desirable than guarding it with star destroyers (ships which could be better put to use on other missions)? Lets get some discussion going!

Exactly. In real life, if you had a species that was willing to cross interstellar space for a chance to fight us, we'd be in some deep $%^&. The most likely attack would come in the form of relativistic kill vehicles, pummeling all industrial and population centers. Our casualtys would number in the billions, and chaos would sweep through the civilised world. Soon after, there would be a fleet of warships in orbit to mop up whats left of humanity, and some ground forces to capture whatever individuals remain (maybe sticking them into zoos). People like to fantasize about waging guerilla warfare against hostile aliens, but the truth is, we'd never get the chance. They would pound us from orbit, bomb us back into the stone age. By the time they deploy ground forces, the aliens would for all intents and purposes have won. If you really want to beat a hostile force of aliens, you're going to need a military grade supercomputer (like skynet). We can't develop strong AI at this point and time, but its definitely a possibility in the next few decades.

Could you elaborate on that? I acknowledge the possibility that some elements of society will look very dimly upon genetically enhanced soldiers. There are alot of ethical boundarys that get crossed with such a project, just like alot of ethical boundarys were crossed when we used nuclear ordnance against japanese civilians. Whether you like it or not, though... If a course of action is seen as militarily expedient, the generals are going to take it. In the decades to come, I foresee humans splitting into many diverse clades through the use of genetic engineering. The differences will be minor at first, but as time passes, there will eventually be entirely new species of humans within our society. And since some of them will be doing jobs that we are unable or unwilling to do (colonising hostile planets, tending to ecologys in the ocean depths), how much could we really complain about them? Yes, and I took all of those things into consideration in my article. Genetically altered or not, they still have human needs that must be attended to. The skills and abilitys desired in a soldier have actually remained fairly consistent throughout history. He needs to be able to march long distances with a pack, make camp in unappealing locations, operate various types of weapons and equipment, work with others as part of a team, engage other humans in lethal combat, etc. Specialisation in humans is different from specialisation in insects

Again, you are talking about these soldiers like they are just another weapon or piece of equipment: Thats not how it is. Human personnel are the integer exponent through which all wars are won or lost. With a project like this, what you are doing is improving the human part of the military, and changing the force on a fundamental level: How exactly do your enemys counteract an advantage like that? They can't, not without raising their own force of metahumans (which takes at least 20 years to do, too late to influence the wars outcome). You seem to be myopically focusing on whether there is a weapon that can kill these soldiers, thinking that if it gets developed and mass produced, they will quickly lose their importance. Thats very much a mistaken opinion: Considering that virtually every weapon in our arsenal (from small arms, to artillery, to aireal ordnance) can kill a foot soldier today, why do we even have an infantry branch? Because, combat is not predicated on the invulnerability of each and every soldier. This topic goes way beyond the simple exchange of bullets between two forces. It goes way beyond whether you can kill a metahuman with small arms fire. This is about better soldiers, who can perform their missions far more efficiently than baseline humans.

You shouldn't worry about cost that much, seeing as the MIC is tremendously expensive by its nature. The war department and its contractors waste stupendous amounts of money on projects that never come to fruition, and no one in a position of authority ever trys to penalise them. If a metahuman soldier project is done properly, it could yield enormous and long lasting benefits: We would have a soldier with combat skills above and beyond what any normal human could hope to achieve. Think of someone like Big Boss, or Todd 3465, but with superhuman strength, speed, and durability. Imagine having even a few thousand men like that! It would give your nation an insurmountable advantage, and would change the nature of war itself. For thousands of years, military innovations have consisted of adding superior tools and weapons to our inventory: The crossbow, the muzzle loading musket, the breech loading rifle, the repeating rifle, then semi-automatics and full automatics. You know what none of these weapons did? They never changed the nature of the man holding them. A human soldier is still a human soldier. No matter how much gear or training you give him, his fundamental psychology and physiology can only be altered so much. Metahumans are much more flexible. They are a sub-species designed to thrive on the battlefield, avoiding all the weakness' of the human body, and adding all kinds of new strengths. We have been developing improved weapons for so long, wasn't it inevitable that we would someday want an improved soldier to go along with them? Some of the initial advantages may dissapear over time, but at the end of the day, these troops are simply better suited for the demands of war than an ordinary human, and thats what counts. Very few military innovations have been transformative in nature: Many of those which claim to be transformative were merely incremental. Having a qualitatively better soldier, though? That would rank right up there with the advent of motorisaton. FYI, a metahuman soldier project is a long term commitment, its not like the military is going to create just one generation: Those soldiers will become an important demograph within your nation, responsible for defense against external threats. If kids are being born every 15 years, that gives you alot of tactical and operational flexibility. After all, their genomes can be altered with every successive generation to meet the changing nature of warfare: If new challenges are encountered, then we devise new adaptations to overcome them (whereas with baseline humans, you are SOL). Their increased survivability is a major selling point, true, but its not like the soldiers will suddenly become useless if new types of weapons are able to kill them: Metahumans are only meant to be tough, not invulnerable. Besides, what are the odds of laser or plasma weapons being introduced? We have been using firearms for half a millennium: It was round shot from 1500 to 1850, then conical bullets from 1850 to the present. Humans are locked into bullets from a cultural and technological standpoint, and thats not likely to change anytime soon.

Because of our ridiculously big brains, humans are tragically vulnerable to heat, cold, injury, hunger, thirst, etc. I've been studying wound profiles and terminal ballistics for years, and you'd be surprised at how much you can do to improve survival rates. I'm no doctor, but I know how bullets affect human tissues. With germline engineering and in vitro fertilisation, you could endow humans with all kinds of features to limit damage. I did a whole post about this on my blog, check it out if you don't believe me. http://kesler12-jamesrocket.blogspot.ca/2014/09/physiology-of-super-soldier.html

You have been misled. To say that the singularity won't happen for hundreds of years is comically misguided. Before this century is out, human civilisation (if it survives at all) will be ruled by a superintelligence. Convergent advances in genetics, nanotechnology, and robotics will create several pathways for the development of superhuman intelligences: These entitys will have enough power to rapidly outcompete baseline humans and gain control over the gross output of the entire world. They will be running the show, and we will just be along for the ride. Regardless of what happens politically, if humans are able to survive the singularity, they will aquire the ability to radically alter their own physiologys. How could this help them survive in environments like venus? Some clades may have completely different body chemistrys, and be swathed in cybernetic equipment. This wouldn't allow them to survive direct and prolonged exposure, but it would greatly reduce the amount of infrastructure needed to keep them alive. They would actually be able to establish a prolonged human presence on venus, instead of an isolated outpost requiring constant babysitting.

Has anyone considered pantropy? Baseline humans would need massive amounts of protection to guarantee their survival on venus. A genetically or cybernetically enhanced superhuman could land on venus with much less fuss. After the singularity, humans will have the power to radically alter their own physiologys, which might lead to entirely separate species. Some of them might actually be able to withstand that kind of environment (at least if they are only partially exposed).

No, I don't think interstellar space travel is going to be a possibility in the 21st century, or even the 22nd. The sheer amount of energy required is a hard limit: Sending humans even to nearby stars is a task for type 1 civilisations. This century will be spend colonising the moon, with manned explorations to the inner planets, and probes to the surfaces of the outer planets (and their satellites). Theres no rush to get to the stars, humanity must learn to crawl before it can walk.

I too have done some thinking on the possibility of genetically engineered soldiers. My area of interest has been adaptations that allow humans to survive gunshot wounds, and other forms of physical trauma. IMHO, your first task should be to determine whether the human metabolism can synthesize all the peptides requires. This is a concern because the vast majority of mammals do not produce venom (the platypus being a notable exception), which suggests there may be some kindof metabolic incompatibilitys.

Great minds think alike. Those are exactly some of the things I mentioned in this thread. These are plausible and original ideas which everyone shoots down without even bothering to demonstrate why they won't work. Thats not their job, granted, but if your going to say that something is debunked, you should at least copy/paste some article proving it. As one example, chemical rockets are quite stealthy compared to electromagnetic engines: With a very small rocket and some concessions to future scientific advances, you could propose an environment where warships can secretly burn along until they get within a few million km of a suspected enemy position. Is that actually possible in the real world? Who knows. Some of the more math literate people here could easily come up with a chart determining how far away engine x or y can be detected, but they don't bother. If they want to shut down the debate on stealth warships, they need to do more than just say 'nah uh!'

If you are launching warships from a space station, it might be possible for the base to offer some concealment: When the ships initiate a burn and head out to their objective, the station could use some kind of broad spectrum IR back lighting to disguise the ships engine exhaust. The people watching via telescope would know that ships had been launched, but they wouldn't know how many or where they were going. Another interesting possibility: If you equip warships with a photon sail, you could use the stations lasers to boost them to their target without being detected. There might be some waste heat released by the beams interaction with the sail, but probably not enough to pick up via IR telescope.

So you can confirm that the 15 million km detection range is accurate? If so, which of the shuttles reaction control system was john schilling referring to, the primary RCS or vernier RCS? Theres a big difference between the two. Thats why we need more exact figures on how sensitive the IR telescopes are. If they can detect the vernier RCS at that distance, then all attempts at stealth are pretty much screwed. But if its just the primary RCS they can detect, you might have some wiggle room. In theory, your ships could use small chemical engines to burn for a long time and then coast, without being detected. The only way for an astromilitary to counter this would be to field literally thousands of space telescopes like WISE. The inner solar system has a radius of 450 billion meters, and a volume of 3.82 × 10 35 meters. Thats quite alot of space to cover.

This is a topic that may or may not have been covered already, but since I couldn't find any direct hints of it, I'll take a chance and post it anyway. Some of you have undoubtedly seen this page at the atomic rocket website, and been sorely disappointed by what you read. Back in the day, I was a fan of the stealth warship archetype that was defined by the USS sulaco. When I read that page several years ago, I couldn't believe that something as weak the space shuttles OMS engines (which have a thrust of just 26,700 newtons) could be detected past the orbit of mars! This didn't seem intuitively possible to me, so I pushed it out of my mind. Recently, though, I've started to look back on this topic and realize that I brushed it aside too quickly. The ability to detect the exhaust plume of a rocket at tens or hundreds of millions of km with an infrared telescope is a major problem if nations are ever planning to wage war in space. I looked at "]the math by john schilling which claims to prove this, and discovered that a 2 meter IR telescope is so sensitive, it can detect a single RCS on the space shuttle firing at a range of 15 million km. I don't have the talent to verify whether this is true or not, but again, it seems pretty unbelievable! One thing thats not clear is whether john is referring to the primary RCS (thrust of 3870 newtons) or the vernier RCS (thrust of 106 newtons). Does anyone know the math behind how infrared telescopes work? Is it just a linear equation, I.E, you half the heat signature and decrease the detection range by half, or is it something more complex? Also, would using a very cold jet of gas forced out by mechanical pressure be more stealthy than a chemical rocket using superheated propellent? I will appreciate any answers you can give!

Agreed. Conventional spacecraft are unacceptable for interstellar space travel, because they have the engines on the bottom and the rest of the ship built on top like a sky scraper. This results in a very long, very heavy, and very wasteful ship (see robert frisbee). By mounting the crew habitat behind the engines, designers can use flimsier materials and skimp on radiation shielding. But there are certain risks that might be encountered by using a tensile truss. For instance, the venture star relys upon r-squared attenuation to protect the crew habitat from the engines, which are treated as a point radiation source. But what about the twin exhaust streams that run within 100 meters of the truss on both sides? They may still subject the crew habitat to dangerous levels of radiant heat and ionizing radiation.

Okay, this has been an interesting discussion so far, but I want to steer things back to the original premise. In this video (http://youtu.be/rWDRq16o6ic), bantokfomoki claims that the ship outputs 174 petwatts via its engines, which is equal to all the sunlight received by earth. But the sun emits this energy from a surface of 2,730,000,000 square meters, whereas the venture star emits this energy from a surface of just 300 square meters. According to him, the engines will therefore be 9,100,000 times hotter than the surface of the sun. Does anyone see the problem with this claim?

There are a few different ways, one is to compare the propellent tanks (of which there are four) to the rest of the ship. If the venture star is 1530 meters long, then the tanks are 78.18 meters in diameter. Therefore, they each have a volume of 2.66 x 10 5 meters, or 266,000 meters. To get your final answer, you just need to know what density the deuterium is being stored at.

Yeah, Ralathon mentioned this back in the last thread. Thing is, while you can use some of the propellant to create a cooling film along the engine chamber, it decreases the exhaust velocity by a large amount (maybe an order of magnitude). I definitely think having unobtainium in the engines helps increase their efficiency: A room temperature superconductor would ensure that most of the reaction byproducts are safely ejected, which minimizes the waste heat. 98% or 99% efficiency is foreseeable. A fusion powered saturn v. Now that would be badass!

Yeah, I remember you. Bantokfomoki can be very pessimistic about the future. Its a bit like lord kelvin passing judgement on heavier than air flying machines. I'm actually not sure what the venture stars dry mass is, but as for the wet mass, 100,000 tons seems reasonable enough. Getting to 70% of light velocity requires high mass fractions, even when you have AMAT (anti-matter) engines. As always, the tsiolkovsky rocket equation is a limiting factor. I agree with you about that. Carrying 2 shuttles on the way there makes sense (since the colony on pandora uses them for alot of different jobs), but they should only be taking 1 shuttle back to earth with them. That would let the venture star carry more unobtainium in its place. Thats kindof a backwards way to determine the exhaust velocity. For all we know, the ship could be using a higher thrust and lower ISP engine, which would increase acceleration at the expense of payload. Remember, official literature has it moving at 1.5 gs for 6 months! Also, aren't gamma rays the main contributor of waste heat in an AMAT engine? If so, why does the 2nd row (0.95 C) emit more gamma rays but absorb less heat than the 1st row (0.77 C)? Thats interesting. Bantokfomoki estimated each radiator as being 80 meters wide and 300 meters long, making for 75,000 square meters each. About the photon sail, do you really think it could be used to radiate waste heat? That would certainly be helpful, given that it has a diameter of 16 km!

This is sortof a follow up to a thread I made almost a year ago about the ISV venture star. As you might remember, a guy named Bantokfomoki made some videos about the ship purporting to show why it could not work. While I agreed with his weak claim that travelling at 70% of light velocity is impossible for a reaction engine, I didn't accept his strong claim that travel to other stars within a human life span is impossible. We all had a good discussion about this, and after the thread got wrapped up, I moved onto other things. But a couple months ago, Bantokfomoki made another avatar video and I offered to show him the errors in his thinking. I wrote two articles on my blog as a rebuttal, and engaged in a debate with him: It seems like I came out as the winner. Even so, I can't help but wonder whether or not my statements were factual, and I wanted to get a second opinion from you guys. Here are my articles http://kesler12-jamesrocket.blogspot.ca/2014/10/bantokfomoki-in-space-part-1.html http://kesler12-jamesrocket.blogspot.ca/2014/12/bantokfomoki-in-space-part-2.html Are there any glaring errors I made with my physics and math, or any points of his I did not adequately address? Go into as much detail as you want.