Discussion in 'Science & Technology' started by Disgustipated, Sep 29, 2010.
Nope it's one.
You should source that.
edit: it doesn't really matter, since embryos are rather light, and we can carry millions of genetically diverse embryos rather cheaply
Source: My Brain
Astronomers no longer sure about Gliese 581g
^Yeah, I posted that before.
It's a conspiracy to cover up the truth: There really IS a habitable planet orbiting Gliese 581!
1\10th was only because at this time, using nuclear pulse propulsion, its the fastest we can go, so thats why I used it. A theoretical fusion engine could get us to 25-30% speed of light. Optimum if it could be done would be to get above 90% because then relative effects really start to shorten the trip from the crews perspective. Found this site that designed a space ship, in theory, based on fusion power, really puts it into perspective.
Was a show on the other day talking about the Oort cloud, so now its believed that it extends out as far as 2 light years. Thats a real problem if we have to crawl out of our system for that long. Also if the Centuri system also extends that far then we would be in an Oort cloud the entire trip going to that system.
In a long long time I'd say.
Very long time, and IMO not going to happen at all if we cant get fusion to work. They still havent solved that one yet either, havent broke ground on DEMO and are still in need of breakthrus before they can even start construction. Fusions been bumped time and again, I'm sure they will miss the 2050 date too, especially considering the current economic downturn.
Not surprised, this crew has jumped the gun at least twice before on planets around this star.
So something is automatically false simply because of its source is outdated? No, for example, you have to disprove the Greek's logic the old fashioned way, not by saying they are outdated and by people who are wrong on other counts.
The SF as references usually are explicitly stated as such as quotes in opening chapters (many textbooks do something similar), or because the SF author actually did legitimate research (such as Asimov's biochemistry works).
And no education in biology? Take a look at his website. http://www.rfreitas.com/ Medical nanorobotics probably require *some* working knowledge of biology...
By the way, the reference I quoted was a logical statement, and do not explicitly state a way that it is possible, just that alternative possibilities should not be ignored outright, which you are doing. I state that non-oxygen utilizing complex life is possible, but not probable due to energy yields. You flat out state it is impossible. You have not provided any evidence anything other than oxygen is impossible. Only absolutely required for life that developed in the presence of oxygen.
Regardless, "complexity" (assuming you mean multicellularity, otherwise it's as silly as the "type" argument that creationists use) is a poorly understood topic. There are multiple competing theories on how multicellularity occurred, and none of them explicitly require oxygen. The most common one was that a cell had a mutation which prevented its daughter cells from separating. This in itself has no evolutionary benefit, so it wasn't selected for until other mutations occurred, such as division of labor, or generation of sticky molecules to adhere to surfaces which are nutrient rich locations, etc.
http://courses.cit.cornell.edu/biog1101/outlines/Bonner -Origin of Multicellularity.pdf
I was simply correcting you on a technicality. Yes, it doesn't help my argument (and I fully realize it), but I don't ignore evidence to the contrary. It simply makes designing something more difficult, which manifests itself as additional engineering challenges, rather than a physical impossibility.
On the off chance you were referencing Project Orion, I thought it was useful to mention that using nuclear bombs as thrust is not exactly optimal with a lot of the energy lost due to it not being directed at the spacecraft effectively. It was so bad to the point that a far less energy expending spacecraft can actually outperform it, simply by taking the quality over quantity approach, rather than the quantity over quality Project Orion took.
What you are suggesting is that the energy requirements alone make it insurmountable, and then went and stated the US energy capacity as a maximum. Yes, some of it is more and more power plants, and others is efficiency, but what makes you so sure that the absolute maximum is the United States current power consumption?
I take it from the approach that if the physics enables it to be possible, it is possible, given sufficient engineering challenges, which are varying in ranks of difficulty, have been bypassed. Obviously it is impossible with current technology, but you flat out state that if it is possible (which your tone indicates you doubt it) no one will finance it under any condition because of its duration (a social problem, not a physics or an engineering issue), and therefore it is forevermore impossible. (not to mention, it is a human societal problem, not all possible intelligent life's societal problems) Given there is a demand for something, eventually even the most costly of operations becomes possible.
Oh, and the "adding more power plants" approach does work to an extent so it's not strictly out of the question; add more rocket boosters, and more stages. You don't need to use the same engine the whole way. Most modern rockets don't. (and in some situations, fun things with conservation of momentum actually make splitting something into a multi-stage rocket is more efficient)
A key difference between scientists and laypeople is that laypeople say improbable things are impossible, while scientists say improbable things are improbable.
Photons are their own anti-particle. Anti-matter isn't this substance that mutually annihilates with matter indiscriminately. At the elementary particle level (standard model level, not proton/neutron/mesons/etc as they are composite particles), they very specifically affect their matter counterpart, and not others. (I recall there being an exception or two, but I am not as well versed in particle physics as I'd like. I might just be confusing it with composite particle-antiparticle collisions.)
Complexity, I'm referring to higher energy life forms like animals, with high energy organs like brains, these require the high energy conversion of oxygen. I'm not simply talking about multicellularty, they may have already discovered such life forms at the bottom of the mediterranean sea. What we are ultimatly talking about is finding intelligent aliens and they are going to be high energy beings that will require oxygen for that energy.
This is what I was getting at, not the power here on earth, that was just a frame of reference, and probably not a good one. Its the power output, engines, on the ship itself I was trying, poorly, to get at. Though I will concede that that is one area we can technically improve on a lot. The amount of energy we need to release to push the ship is staggering, this was my point about the atomic bomb example, that we need to release that much energy, that fast, in some kind of controlled manner. If we cant control that much energy, that fast, then we will have to release it slower and that just increases acceleration time and trip time... The picture that comes to my mind is the Corellian corvette from star wars, all engines
Right, because there is no way of obtaining energy that doesn't require Oxygen...
Seriously, physics is simple, so we have a good reason to expect that stars and planets elsewhere is similar to our sun and planets in our solar system. That's just because there is not all that much that can vary between the conditions here and somewhere else in space. That's because physics is simple.
Biochemistry is unimaginably more complicated. The number of variables which come into play are beyond our comprehension. It is also terribly understood. We are a million miles away from describing each unique reaction that happens in the human body, let alone being able to predict how a different set of reactions could exist in another organism. For this reason, what life is like out there is beyond anyone's guess. Saying it must be carbon or oxygen based is ludicrous.
The only thing that we can do is if someone provides a detailed blue print of an organism, we may be able to say that it cannot exist (provided the blue print is incredibly detailed). That is vastly different to rullng out anything that doesn't use oxygen.
Well, on the other end of the spectrum, instead of going for quality of molecules (high energy per unit), there is quantity of molecules.
Assuming the concentrations of the molecules are high enough, you can just simply get them to consume large amounts of molecules to obtain their high energy needs. With a higher food demand, they might simply become more intelligent to acquire the food efficiently, much like how mammals tend to be more intelligent in general. (most cold blooded animals tend to be on the lower end of intelligence, as they don't have to consume as much food to maintain a constant body temperature, and don't have to work as hard to survive)
They would also be more efficient energy wise
Eating more food gains you nothing if you cant metabolize it... Chemistry IS physics.
Basically, Mars would be a far better candidate for life if it were larger. Say, the size of Earth, for example. Higher gravity and escape velocity would allow it to retain a much thicker atmosphere over geological timespans, leading to a stronger greenhouse effect, higher temperatures, better conditions for liquid water on the surface, etc. Having a mostly-molten core with active plate tectonics and a strong magnetic field like Earth wouldn't hurt either.
I don't think there's going to be a way to get a magnetic field in the next couple hundred years, so you really have to start thinking about how to get an atmosphere first.
To get an atmosphere you should probably start by building factories that convert stuff to greenhouse gases. You need to melt the caps and eventually hope that the planet arrives at a balance that allows for atmospheric pressure... Once you have atmospheric pressure you can start seeding the planet with life of some sort - life that can convert carbon dioxide to oxygen.
Over dozens of thousands of years this will slowly introduce more and more oxygen into the atmosphere and allow for more varieties of life. At that point you introduce more complex vegetation, including eventually bushes and trees, and even shrubberies.. After that you add dolphins, turkeys, elephants, carrots, etc. Fix up some fjords, build a strip mall, affordable housing, a spaceport, name the capital Nova Zielona Gora, and you have yourself a habitable planet, ready to be colonized by whatever the hell happens to humanity in the next 100,000 years
Take a day off, write a book, etc.
Terraforming Mars is the stupid way, the smart way is Marsiform Terrans. It's easier to modify a 70 kilogram human then a 642 yottagram planet
As far as I know, a terraformed Mars wouldn't last long, since it's so small. The atmosphere will drift away after about a few millions of years, and would eventually revert to its pre-terraformed state.
Well, a 'few million years' is an incredible timescale to plan at. I care quite about about global warming, but discussion of AGW that goes beyond 1000 years kinda makes me tune out. Too much will be different within 1000 years such that worrying about 'a few million years' is kinda pointless. We could have dozens of cataclysms and still be a space-faring species again.
Marsiforming humans is a totally cool concept. It would require advanced genetic knowledge, obviously. Since genetics is becoming an engineering science, more and more people will be able to use their schooling or money to speed genetics research.
And, as an aside, SETInstitute held a conference a little while back. An actual scientific conference. Many of the talks were sometime interesting, too. Some, I didn't really find interesting, because it was too specialised. LOTS of talks.
That's their main channel, to peruse the talks.
Well, the fact that we're already here very likely doesn't affect the probability of there being intelligent life nearby.
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