My question relates to the colonization of venus' surface.
I haven't seen this posted elsewhere so I don't know how feasible it is or is not. Could humanity construct something similar to a supertanker ship around a hydrogen rich body such as Jupiter, fill it with liquified hydrogen, and crash it (containing millions of gallons of liquid hydrogen) into the venusian surface, releasing a massive cloud of hydrogen to react with the CO2 in the atmosphere assisted by the high surface temperatures to begin cooling the planet??
A simulation of >1% hydrogen in Venus' atmosphere using universe sandbox shows a very gradual decline in surface temperature year on year. Combined with solar reflector at the legrange point could cool the planet to more tolerable levels to allow surface landing and further terraforming efforts.
If the moon has a weak magnetic field could that be boosted by placing a copper anode/cathode at the poles powered by nuclear energy? Creating an excess of negatively charged particles at the north pole and positively charged particles at the south, creating a push/pull effect.
What about a powerful magnet over the northern pole to assist the existing magnetic field in capturing charged particles and boost the magnetic field strength.
The result of reaction between CO2 and H2 is CH4+H20, and the thing is that you replace one greenhouse gas with two even stronger one, thus burning the planet even deeper in hell. So, the reasonable move is to build orbital manufacture that extracts CO2 convert it into basic organic and distributes it across the solar system as a starter for any needed chemistry. Moreother when you mainly disassemble the atmosphere it begins much easier to launch the cargo from the planet surface and in this perspective it is impracticable to seek somethere for nytrohen and water to create new atmosphere if you can optimize your resource usage in many ways converting the planet to a part of dyson swarm.
If your eyes and your gravity sensors (a.k.a. sense of balance a.k.a. inner ear) don't match, you can suffer vertigo. You can get motion sickness in an IMax theater for example. Being unable to see "outside" helps, but it's not everything.
There's problems with moving your head in the shifting gravity field. And there's problems with tidal forces, (though mostly it's just when you head goes up and down), but humans aren't going to be comfortable in a rotating cylinder less than twice their height in radius (i.e. 4m)
Also, walking "east" (spinward), "west" (widdershins), and "north" are all going have slightly different forces. The larger the radius the less noticible this is. Whether this causes problems is hard to say, but it will certainly make sportsball more challenging.
Spincalc is a pretty cool tool, and it has a number of references at the bottom of the page.
So I have two questions about the common for Isaak approach about spotting alien civilizations.
First there is some regions in our galaxy that are actual black spots in terms of visible light covered with the gas and dust remaining from the active star formation and more this regions are full of stellar objects that are visible only in infrared part of light specter. I acknowledge that the reason why we observe only infrared light is bounded to the property of interstellar dust to absorb all other length of spectrum and thus ionise and ions as known emit infrared. But in my view this all seems like expanding 2+ kardashev civilization which decided in order to maximize the energy efficiency to build up closer to the galactic core in such way achieving several purposes: higher star density means less delay in communication, abundant amount of raw matter means less waste disassembling stars, waste heat is used to create ionized gas which can be subsequently used either by fusion or by mass energy conversion through black hole in addition it is easier to direct ions than uncharged particles and charged heated particles would not voluntarily collapse into new star. I don't pretend every dust cloud is alien occupied but what are arguments for highly developed civilization is not colonizing some centrale part of our galaxy if it looks like some classic description for space region under the control of K2. So my point is that there is no absence of space which matches the criteria proposed in dyson dilemma and thus the Fermi paradox doesn't exist. As said above is quite obvious there should be some obvious flaw otherwise Isak wouldn't be so in love with dyson dilemma. So I ask you to point out why central part of our galaxy doesn't match the place occupied by some advanced civilization.
Second why even bother building more than one dyson swarm rather than switch to black holes as fast as possible. And assuming that faster you convert maximum mass into black hole more total energy output you get wouldn't it be more rational to search for such type of events in past rather than for dyson swarns. So whats are argument not to sail the whole home star system in direction of nearest black hole and grab it power to move around the galaxy shrinking apart stars and utilizing their remnants even to feed the initial black hole or creating new one or not if you are afraid of civilization divergence and at some point reassembling the whole galaxy into quasar in order to reach other galaxies and repeat everything at bigger scale. I assure that first quasars are so ancient that there is little chances of them to be artificial but it doesn't matter that this is the fastest possible engine and intelligent life wouldn't use it if possible for expansion.
There are several misconceptions here. One, Sirius A & B are too far away from one another (at an average distance of 25 AU) to significantly contribute any gasses to one another, although star A is indeed blowing gas at star B as we speak. This is not a problem now, but when star A becomes a asymptotic giant star in its later life, star B would need to consume a whopping 0.3 to 0.4 solar masses of material during a close approach to trigger any sort of reaction in its core (this is highly unlikely). Luckily for any nearby stars, this accretion by star B is too little and too slow to actually trigger a supernova - it may instead undergo a recurrent nova. I say "nearby stars" and not Sol because Sol and its solar-system will not be anywhere near the Sirius binary system when star A undergoes its final stellar evolution process. The positions of stars in the Milky Way and their distance from one another are constantly changing as the stars circles the galactic center - 500 million years from now Sirius will not be anywhere near Sol or any colonies we have (or had) outside of it.
If a supernova did occur so close to a K2 civilization, this would spell doom for all biological life in their solar-system and other for dozens of light-years around. Physically the planets and sun would be unaffected, but the life on (or around them in space) would be destroyed by gamma rays - unless the K2 could shield their planets and/or solar-system from the radiation - which is tricky because we don't know of many materials that could resist the intense radiation.
This concept actually has it's origins in a paper by Paul Birch . The materials and energy required to harvest and transport the hydrogen from the outer solar-system to Venus would make this unpractical at best. Collecting and diverting comets would be far easier and more beneficial. That being said, no method of terraforming is easy or inexpensive - so as far a "yay" or a "nay" goes - I would respond with a "meh". It's theoretically possible - but a lot more then just slinging gas canisters will be needed to make Venus habitable. I would say though that colonizing Venus will be a better investment than doing so with Mars.
Who is to say that that isn't what extraterrestrials are doing? Nevertheless, bear in mind that the uses of Dyson swarms go far beyond basic energy collection - the constituents of their mass are also made with living space and infrastructure in mind. All in all, a star is a lot more practical for a K2 civilization to live by and collect energy from. Plus, colonizing and utilizing the solar-system around a star offers countless opportunities for efficiency long before blackholes become possible to use. K3 civs may use blackholes more for various reasons, but in any case the Dyson Dilemma still poses its ominous question: Why don't we see the signs of interstellar industry anywhere? The only difference here being that now we need to consider why there isn't any activity around blackholes as well as stars. All in all, more questions are raised, rather than being eliminated.
The Creating a magnetosphere thread has been merged into this thread.
Hello all, I remember Isaac mentioning a specific type of space fountain, in which a large structure with a city on top continuously pumps air from the lower atmosphere to maintain pressure. Does anyone know what this is called, or if there are any sources I could find to research this specific method of atmosphere supply? Additionally, would any sort of retaining walls be necessary, or perhaps only necessary if one wants to avoid hurricane-force winds within the city?
Hi, i am a long-time SFIA-viewer (fan) and like most of us i dont think FTL will ever be possible, but for a few weeks now i have this idea of a possible FTL-ship in my head which i never heared of anyware. it depends on the properties of dark energy and some othe stuff and probably will not work, but i cant think of any scientific proof against it... so here it is:
How about moving a spaceship by creating chunks of spacetime behind it and (maybe, if possible) deleting chunks of spacetime in front of it? as far as i know dark energy is supposed to do exactly that all the time. your "speed" should be limited only by how fast you can create (and maybe delete) spacetime.
If dark energy realy is creating new spacetime this should work (?) or is dark energy only stretching spacetime? Isaac always say it is created, not stretched
The Possible FTL? thread has been merged into this thread.
Don't worry, Sirius B can't go supernova. It is around 20AU away from Sirius A and so they are too far apart for Sirius B to pick up mass from accretion during Sirius A's red giant phase. So it ain't gonna reach that Chandrasekar limit. All supernova candidates are several hundred light years away or more. We're in a really sweet spot in the galaxy right now.
You are thinking of the Alcubierre drive, Gorwo. Issac covered it on the FTL series. The problems are you need to discover some form of matter with negative mass and you would have to build the ship to withstand temperatures similar to those inside the cores of the largest stars. And, yes, the expansion of spacetime due to dark energy creates new spacetime. And, since spacetime itself has a certain intrinsic energy, the total energy of the universe is always increasing. Imagine the universe continuing on past heat death(which assumes a continuing expansion) - possibly infinite energy but no way to use any of it. Bummer.
My first question is why? The only advantage of a terraformed Venus over any other body in our solar system is it's similar g compared to earth. Is that reason enough? I'll assume it is or Venus has another reason that makes it worth the effort. The first problem is dealing with the nightmare of an atmosphere. It's not just hot it's also acidic and at a super high pressure. Simply dumping in some hydrogen or water won't do nearly enough. Venus got rid of it once and it will do it again.
No, the Alcubiere Warpdrive works (as you say) by squeezing or stretching spacetime, my idea works by creating/destroying it. As far as i know we dont realy have a full understanding of dark energy, i. e. we cannot say if creating/destroying spacetime is possible. If it is possible you could "delete" spacetime in front of you to get "closer" to your destination.
Actually, your limit would be the speed at which the air could go, basically the speed of that medium heated to atmospheric temperature (i.e. it becomes a low temperature air rocket). This will be roughly the speed of sound, which changes with temperature and density and molecular weight of the medium. On the earth, at sea level, you may get to 400 m/s (speed of sound at standard temp and pressure in air is ~331 m/s).
Well thanks that answered one question. Energy doesn't have to be added to the system for particles to appear.
He didn't get deep into where the particles go when they disappear, other than to imply they annihilate with their birth-twin antiparticle.
I wonder if interstellar and intergalactic space generate new matter as the universe expands. They are the flattest vacuums in nature. If so the universe could expand forever and always have about the same density.
If two particles are born together and space expands between them, I think they would be less likely to find each other again and annihilate. It would create a bias toward creation over destruction. Multiplied by the volume of interstellar space, it would be very common.
I guess a material question is, if the universe is expanding and more space is being made, is vacuum energy diluted, or does its density stay the same?
Space is expanding at large scales. At the scales at which virtual particles pop into and out of existence space isn't expanding significantly...at least not yet. The density of matter in the universe is decreasing