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Science General

Last posted Aug 19, 2012 at 06:44PM EDT. Added Jul 01, 2012 at 05:40PM EDT
118 posts from 23 users

Yes, It’s back. No really.

I found a lack of science here, and because the last one was locked, I don’t see why I can’t start it again…

Discuss Science.

Jul 01, 2012 at 05:40PM EDT
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Good, because I only believe in science!

Jul 01, 2012 at 05:53PM EDT
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and , with a composite system of , are considered seperable states. But in the form of is seperable if yielding and . It is inseperable if .

Jul 01, 2012 at 05:59PM EDT
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Since the thread would otherwise fall into chaos and random equations/chemistry puns, I am going to give this thread a topic.

METHODS OF COLONIZING OTHER PLANETS AND REASONS FOR DOING SO.

DISCUSS.

I think that mars would be a great candidate, for many reasons.

1.) It would be relatively easy to colonize. The soil is chock full of oxygen, iron, silicon, aluminum, and all sorts of other goodies that could be made use of. We would just send a home base pod for the colonists to live in, the equipment required to decompose the soil into it’s base elements, and enough oxygen/food to last them until they can start building their own structures and making internal food farms.

2.) It would make a great jumping off point for exploring deeper into space. Load up just enough stuff to get to Mars, then restock on mars and go deeper into space.

3.) With new theoretical propulsion systems (Using fusion to produce gasses and whatnot that are propelled out of the ship), we can reach Mars within weeks instead of months.

4.) Mars is the closest planet that we could survive on. Venus is simply too hot for us to possible survive on.

Jul 01, 2012 at 07:13PM EDT
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ConnerABacon wrote:

Since the thread would otherwise fall into chaos and random equations/chemistry puns, I am going to give this thread a topic.

METHODS OF COLONIZING OTHER PLANETS AND REASONS FOR DOING SO.

DISCUSS.

I think that mars would be a great candidate, for many reasons.

1.) It would be relatively easy to colonize. The soil is chock full of oxygen, iron, silicon, aluminum, and all sorts of other goodies that could be made use of. We would just send a home base pod for the colonists to live in, the equipment required to decompose the soil into it’s base elements, and enough oxygen/food to last them until they can start building their own structures and making internal food farms.

2.) It would make a great jumping off point for exploring deeper into space. Load up just enough stuff to get to Mars, then restock on mars and go deeper into space.

3.) With new theoretical propulsion systems (Using fusion to produce gasses and whatnot that are propelled out of the ship), we can reach Mars within weeks instead of months.

4.) Mars is the closest planet that we could survive on. Venus is simply too hot for us to possible survive on.

Now THIS is a thread I could get used to.


It’ll probably be at least another 30 years or so before civilians will begin to establish colonies on Mars, and even that’s an optimistic estimate. The biggest obstacle right now is that the time and resources to get there with current technology would simply be too large. I think it’s 3 years travel and as much rocket fuel and food as that implies. Fortunately, some of the biggest hurdles will no longer be a problem with some near-future breakthroughs. I’ve heard estimates that nuclear power will become practical within 10 years. Being largely more efficient than any other contemporary propulsion system, it’d help with SO many things that are obstacles right now. Other than that, the biggest problems would include the difficulty of establishing working ecosystems in an essentially arid environment. Simply getting the project off the ground would mean years of construction long before any civilian settlement would be possible.

I also heard that one of the moons of the gas giant planets (Possibly Venus or Neptune) would be an even more feasible candidate for colonization than Mars, and could even contain water.

Last edited Jul 01, 2012 at 10:45PM EDT
Jul 01, 2012 at 10:43PM EDT
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Pseudogenesis wrote:

Now THIS is a thread I could get used to.


It’ll probably be at least another 30 years or so before civilians will begin to establish colonies on Mars, and even that’s an optimistic estimate. The biggest obstacle right now is that the time and resources to get there with current technology would simply be too large. I think it’s 3 years travel and as much rocket fuel and food as that implies. Fortunately, some of the biggest hurdles will no longer be a problem with some near-future breakthroughs. I’ve heard estimates that nuclear power will become practical within 10 years. Being largely more efficient than any other contemporary propulsion system, it’d help with SO many things that are obstacles right now. Other than that, the biggest problems would include the difficulty of establishing working ecosystems in an essentially arid environment. Simply getting the project off the ground would mean years of construction long before any civilian settlement would be possible.

I also heard that one of the moons of the gas giant planets (Possibly Venus or Neptune) would be an even more feasible candidate for colonization than Mars, and could even contain water.

I’m going to split up my reply into several points.

1.) it takes only a few months to get to Mars in the perfect launch window using conventional rockets.

2.) If we use fusion powered thrust, the time to get to mars is shrunk down to a few weeks. Fusion can already be done with modern technology (We can sustain fusion for a few minutes at a time, IIRC), doing it on a spacecraft designed for the task wouldn’t be that much of a stretch.

3.) We could first send all the structures alone, then send the people and whatnot.

4.) Virgin Galactic, a privately owned spaceflight company, is doing it’s first commercial passenger flights into space this year (If there are problems, they’re launching in 2014 by the latest).

.
.
.

On the topic of ecosystems:

All the stuff would have to be internal. Plants would be grown inside, power generated by solar panels, a mine that is air-tight and accessed from indoors, etc.

I think that the best setup would be a circular structure. One section could be the farm/air circulation system. The plants filter the carbon dioxide out of the air, and convert it into oxygen for us to breath. Fans then circulate the air around the entire structure.

Another section, ideally right next to the farm/air circulation section, would be the housing. Just a bunk for each person and a central hallway for everyone to go through.

The rest could just be storage and general purpose work areas.

In the center of the entire structure could be a glass dome (The kind made out of lots of triangles) that would be a recreation area for the crew. In the middle of this area would be the mine entrance, which could potentially be carved into more usable area.

Just send more people in periodically and let the colonists reproduce, and you could have a thriving civilization on Mars.

Last edited Jul 01, 2012 at 11:43PM EDT
Jul 01, 2012 at 11:43PM EDT
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ConnerABacon wrote:

Since the thread would otherwise fall into chaos and random equations/chemistry puns, I am going to give this thread a topic.

METHODS OF COLONIZING OTHER PLANETS AND REASONS FOR DOING SO.

DISCUSS.

I think that mars would be a great candidate, for many reasons.

1.) It would be relatively easy to colonize. The soil is chock full of oxygen, iron, silicon, aluminum, and all sorts of other goodies that could be made use of. We would just send a home base pod for the colonists to live in, the equipment required to decompose the soil into it’s base elements, and enough oxygen/food to last them until they can start building their own structures and making internal food farms.

2.) It would make a great jumping off point for exploring deeper into space. Load up just enough stuff to get to Mars, then restock on mars and go deeper into space.

3.) With new theoretical propulsion systems (Using fusion to produce gasses and whatnot that are propelled out of the ship), we can reach Mars within weeks instead of months.

4.) Mars is the closest planet that we could survive on. Venus is simply too hot for us to possible survive on.

I’d like to go into methods for a little bit, because it’s a very interesting part of the subject.

Theoretically, we could use matter-antimatter collisions as a way to create ultra-efficient propulsion systems. In a matter-antimatter collision, the particles destroy each other and turn all of their mass into energy (Gamma-rays, to be specific) that flies out at the speed of light. The term “ultra-efficient” is a massive understatement here, now that I think about it. It is 100% efficient. But you can’t use just any antimatter, though. A normal matter-antimatter collision will instantly decay into gamma-rays, which cannot be directed electromagnetically, and thus cannot be used as a form of propulsion.

BUT, as Robert L. Forward discovered in the 1980s, a collision between protons and antiprotons happens in two stages. First they produce particles called pions, which can be influenced electromagnetically. The pions then decay into gamma rays. What this means is that by colliding protons and antiprotons, we can direct the product of their destruction into a propulsive jet without sacrificing the perfect efficiency!

Which is why, if we figure out how to create enough of it, we definitely need to use it in future starships.

Jul 01, 2012 at 11:58PM EDT
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[Disclaimer: I’m no scientist, just an interested layperson. So anything I say from hereon out is either an educated based on current knowledge or something I’ve read. It’s easier than saying “I’m not sure, but…” every time.]



Anywho, the only problem I see with what you said is that fusion generators are still very far from being in usage. The problem with fusion is that it produces a massive amount of energy, tons more than fission does. Because of this, fusion plants don’t even currently exist, at least to my knowledge. Compacting that kind of containment down into the size of a space shuttle, and one designed to house people no less, when we can’t even establish fusion reactors on Earth is a scientific impossibility for the time being.

Other than that, everything else seems feasible, and the best solution. The only issue I see with the biospheres is that they would require far greater technological and economical resources to build and maintain than farms on Earth, making civilian colonization both redundant and economically impracticable, except for the wealthiest individuals. Then again, there really isn’t another way, and it’d be a huge boon for scientific study of Mars and different/biopod ecosystems in general. It’s the kind of thing that makes you feel like a kid again. :3



(Again, apologies if I’m showing my ignorance here. Like I said, I’m no expert.)

Last edited Jul 02, 2012 at 12:01AM EDT
Jul 02, 2012 at 12:01AM EDT
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ConnerABacon wrote:

Since the thread would otherwise fall into chaos and random equations/chemistry puns, I am going to give this thread a topic.

METHODS OF COLONIZING OTHER PLANETS AND REASONS FOR DOING SO.

DISCUSS.

I think that mars would be a great candidate, for many reasons.

1.) It would be relatively easy to colonize. The soil is chock full of oxygen, iron, silicon, aluminum, and all sorts of other goodies that could be made use of. We would just send a home base pod for the colonists to live in, the equipment required to decompose the soil into it’s base elements, and enough oxygen/food to last them until they can start building their own structures and making internal food farms.

2.) It would make a great jumping off point for exploring deeper into space. Load up just enough stuff to get to Mars, then restock on mars and go deeper into space.

3.) With new theoretical propulsion systems (Using fusion to produce gasses and whatnot that are propelled out of the ship), we can reach Mars within weeks instead of months.

4.) Mars is the closest planet that we could survive on. Venus is simply too hot for us to possible survive on.

I’m Impressed Sting! You started a good topic.
Ok. Mars might be a good planet to colonize, but it lacks several things that Earth has.
1. The Magnetosphere – This is created by the flowing of the liquid core of a planet. Without this The Planet cannot protect itself from Solar wind. So it may possibly boiled the water there.
2. Gravity – Gravity on Mars is 38% of the gravity on Earth. So the Atmosphere is thinner than Earth. and all the light gasses like Hydrogen would have probably left Mars.
3.The Atmosphere – As Previously mentioned the Martian Atmosphere is thin. It is also made of Carbon Dioxide. And the Pressure is relatively low.

Jul 02, 2012 at 12:17AM EDT
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Greninja wrote:

I’m Impressed Sting! You started a good topic.
Ok. Mars might be a good planet to colonize, but it lacks several things that Earth has.
1. The Magnetosphere – This is created by the flowing of the liquid core of a planet. Without this The Planet cannot protect itself from Solar wind. So it may possibly boiled the water there.
2. Gravity – Gravity on Mars is 38% of the gravity on Earth. So the Atmosphere is thinner than Earth. and all the light gasses like Hydrogen would have probably left Mars.
3.The Atmosphere – As Previously mentioned the Martian Atmosphere is thin. It is also made of Carbon Dioxide. And the Pressure is relatively low.

Ah, I forgot to bring gravity and the magnetosphere into account.

Gravity isn’t too much of an issue. The biggest problem is that it will be a hard transition when you go from mars back to earth. Other than that, it’s not too much of an issue.

The magnetosphere/solar wind problem is mitigated easily enough by simply making the colonies radiation-protected. Lead works best, but is very heavy and not practical to send to another planet. Water is also very effective at shielding against radiation.

If worst comes to worst, the colonists can simply hide underground until the solar storm passes.

About the atmosphere:

This is mostly a moot point, because the colonies would be airtight and self-sustaining. However, it does make work outside of the base very dangerous and much harder to do. This is addressed with my point about the work areas and even the entrance to the mines being inside the colony itself, so as to avoid air leakage.

Something I just thought of is the problem of structural breaches. There wouldn’t be enough time to patch it with welding or a similar thing. I think that the simplest solution would be to develop a sprayable substance that very quickly hardens. You just spray the breach with this stuff (Assuming it’s a small breach no larger than maybe a dozen square centimeters), and it hardens onto the sides of the breach, then just sticks to itself until it seals the hole. Later, you can add a more permanent fix.

(About you being impressed: I’m not an idiot, as much as I make it seem so :(. I’m just really silly sometimes and have a habit of not thinking very much before doing things. My sense of humor isn’t that good unless I’m building on something that someone else already started, and even then I quite often take it too far.)

Last edited Jul 02, 2012 at 12:43AM EDT
Jul 02, 2012 at 12:42AM EDT
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Greninja wrote:

Thanks for rebooting the thread, Quantum!

Pretty much anybody who remembered or bothered could have done so, buuuuut…Sorry I made this thread and then ditched this thread, I had to go at the time.

Jul 02, 2012 at 03:08AM EDT
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Piano wrote:

I’d like to go into methods for a little bit, because it’s a very interesting part of the subject.

Theoretically, we could use matter-antimatter collisions as a way to create ultra-efficient propulsion systems. In a matter-antimatter collision, the particles destroy each other and turn all of their mass into energy (Gamma-rays, to be specific) that flies out at the speed of light. The term “ultra-efficient” is a massive understatement here, now that I think about it. It is 100% efficient. But you can’t use just any antimatter, though. A normal matter-antimatter collision will instantly decay into gamma-rays, which cannot be directed electromagnetically, and thus cannot be used as a form of propulsion.

BUT, as Robert L. Forward discovered in the 1980s, a collision between protons and antiprotons happens in two stages. First they produce particles called pions, which can be influenced electromagnetically. The pions then decay into gamma rays. What this means is that by colliding protons and antiprotons, we can direct the product of their destruction into a propulsive jet without sacrificing the perfect efficiency!

Which is why, if we figure out how to create enough of it, we definitely need to use it in future starships.

Unless you’re using the term in a manner with which I am not familiar, you are mistaken about one thing: there is no such thing as “100% efficient” according to the laws of thermodynamics. (Also, somewhere farther up in the thread, somebody referred to Venus as a gas giant, which is also incorrect.) That aside, I had a bigger point to make.

Flipping the topic around and going into an area many would consider pseudo-science, what about extraterrestrial aliens coming to visit earth? I was thinking about this last night because we’ve been seeing some strange lights at night over our house, and I know many people immediately think

I remain skeptic however, and I think I figured out why. Even assuming that these space travelers would have much more impressive technology than ours, it’s got to be quite an effort no matter how it’s done to travel hundreds of light years to visit another planet. Why would you go all that distance and then not make some sort of public contact? Why travel unimaginable distances just sit around in our upper atmosphere making some spooky lights? Thoughts?

Jul 02, 2012 at 02:47PM EDT
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Brucker wrote:

Unless you’re using the term in a manner with which I am not familiar, you are mistaken about one thing: there is no such thing as “100% efficient” according to the laws of thermodynamics. (Also, somewhere farther up in the thread, somebody referred to Venus as a gas giant, which is also incorrect.) That aside, I had a bigger point to make.

Flipping the topic around and going into an area many would consider pseudo-science, what about extraterrestrial aliens coming to visit earth? I was thinking about this last night because we’ve been seeing some strange lights at night over our house, and I know many people immediately think

I remain skeptic however, and I think I figured out why. Even assuming that these space travelers would have much more impressive technology than ours, it’s got to be quite an effort no matter how it’s done to travel hundreds of light years to visit another planet. Why would you go all that distance and then not make some sort of public contact? Why travel unimaginable distances just sit around in our upper atmosphere making some spooky lights? Thoughts?

Yeah, that’s why you may be able to see a little awkwardness in my transition from ultra to 100%. I was unsure if the laws of physics allowed such a thing.

Jul 02, 2012 at 02:53PM EDT
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Do you believe it’s at all possible for the human race to get their hands on (or not as the case may be) anti-matter? Considering it’s the dark twin of matter that ‘lost’ – so to speak – when it came to creating the Universe.

Anti-matter to matter collisions for 100% efficiency? That seems a little too difficult if you ask me.

Last edited Jul 02, 2012 at 03:53PM EDT
Jul 02, 2012 at 03:52PM EDT
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“(Also, somewhere farther up in the thread, somebody referred to Venus as a gas giant, which is also incorrect.)”

Oh christ, I was trying to refer to something like Neptune and Uranus. :S I’ve never been good with names.

Jul 02, 2012 at 05:49PM EDT
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量子 Meme wrote:

Do you believe it’s at all possible for the human race to get their hands on (or not as the case may be) anti-matter? Considering it’s the dark twin of matter that ‘lost’ – so to speak – when it came to creating the Universe.

Anti-matter to matter collisions for 100% efficiency? That seems a little too difficult if you ask me.

We’re pretty sure that particle colliders have created minute amounts of anti-matter, but we’re not positive on it. If scientists are correct, we could use particle colliders to generate anti-matter.

All that anti-matter is, is our matter but with an opposite charge. We can already create electrons with a positive charge (Called positrons, if I remember correctly), we just need to produce negatrons (Or whatever you want to call them), which are protons with a negative charge.

Jul 02, 2012 at 06:02PM EDT
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量子 Meme wrote:

Do you believe it’s at all possible for the human race to get their hands on (or not as the case may be) anti-matter? Considering it’s the dark twin of matter that ‘lost’ – so to speak – when it came to creating the Universe.

Anti-matter to matter collisions for 100% efficiency? That seems a little too difficult if you ask me.

That’s something I’ve never understood about sci-fi stories such as “Star Trek” that use antimatter as a source of energy.

He’s right that you get incredible output of energy out of just a tiny bit of starting material, so even though physics says we can’t manage 100% efficiency, it hardly matters as you’re dealing with huge amounts of energy. A gram of matter broken down entirely into energy is equivalent in power to over 500,000 gallons of gasoline/petrol. While this sounds great, there are two big questions remaining.

First, where are you going to get antimatter to fuel your ship? It’s certainly not lying around waiting for us to pick it up and feed it into the fuel reactor. You’d either have to find some way out in space (in which case we still have the same problem of how to travel with less-efficient means) or you’d have to manufacture it. But while scientists have methods of manufacturing antimatter, it takes more energy to make it than you get from using it. (Producing antimatter costs scientists about $25 billion per gram.)

Secondly, and far more important in my mind, is the question of storage. What exactly is your “gas tank” going to be made of? Whatever kind of vehicle you use anywhere in any circumstance, you need a container to store fuel reserves that is made of a substance that will not react with the fuel and make it unusable. So what is that for antimatter? Well, it can’t be made of any “normal” material, because the antimatter would annihilate itself and its container. If you could make a container out of antimatter, you still need to figure out how to store that container safely. Certain methods have been explored, and the folks at CERN have managed to create about 300 atoms of antihydrogen, some of which they were able to hold in storage for a little over 15 minutes before they were annihilated. In other words, we’ve got a long, long way to go before we can fuel a ship in this manner.

Jul 02, 2012 at 06:42PM EDT
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ConnerABacon wrote:

We’re pretty sure that particle colliders have created minute amounts of anti-matter, but we’re not positive on it. If scientists are correct, we could use particle colliders to generate anti-matter.

All that anti-matter is, is our matter but with an opposite charge. We can already create electrons with a positive charge (Called positrons, if I remember correctly), we just need to produce negatrons (Or whatever you want to call them), which are protons with a negative charge.

electrons -> positrons
protons -
> antiprotons
neutrons --> antineutrons

The folks at CERN have managed to make make full-fledged antihydrogen, and nuclei of antideuterium and antihelium.

BTW, I should have said that pretty much all my data for the last two posts was pulled out of Wikipedia articles Mass–energy equivalence, CERN, Antimatter, and Antihydrogen.

Last edited Jul 02, 2012 at 06:51PM EDT
Jul 02, 2012 at 06:50PM EDT
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Brucker wrote:

electrons -> positrons
protons -
> antiprotons
neutrons --> antineutrons

The folks at CERN have managed to make make full-fledged antihydrogen, and nuclei of antideuterium and antihelium.

BTW, I should have said that pretty much all my data for the last two posts was pulled out of Wikipedia articles Mass–energy equivalence, CERN, Antimatter, and Antihydrogen.

Wouldn’t an anti-neutron just be a neutron? Since neutrons don’t have a charge, neutrons should be compatible with matter and anti-matter.

Correct me if I’m wrong, please _

Jul 02, 2012 at 07:34PM EDT
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And once again, Brucker comes into a thread and makes us realise that everything we’ve said is incorrect.

Jul 02, 2012 at 07:43PM EDT
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Not everything I’ve said is incorrect :D

i guess that means I know everything.

Jul 02, 2012 at 08:22PM EDT
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Brucker wrote:

electrons -> positrons
protons -
> antiprotons
neutrons --> antineutrons

The folks at CERN have managed to make make full-fledged antihydrogen, and nuclei of antideuterium and antihelium.

BTW, I should have said that pretty much all my data for the last two posts was pulled out of Wikipedia articles Mass–energy equivalence, CERN, Antimatter, and Antihydrogen.

Living up to that username. :p




In a similar vein to what’s been said earlier, I’ve never fully understood how we would even be able to store and transfer antimatter. I thought one of its properties was that once it came into contact with matter, both would be instantly “destroyed”, meaning converted into massive quantities of energy. Even if we could create it, it would be impossible to store using traditional methods.

Jul 02, 2012 at 08:51PM EDT
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Pseudogenesis wrote:

Living up to that username. :p




In a similar vein to what’s been said earlier, I’ve never fully understood how we would even be able to store and transfer antimatter. I thought one of its properties was that once it came into contact with matter, both would be instantly “destroyed”, meaning converted into massive quantities of energy. Even if we could create it, it would be impossible to store using traditional methods.

Magnetically suspended inside a vacuum.

That’s how you transport antimatter.

Jul 02, 2012 at 09:17PM EDT
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guys. we are already colonizing mars. google Mars One.

Jul 02, 2012 at 09:28PM EDT

ConnerABacon wrote:

Wouldn’t an anti-neutron just be a neutron? Since neutrons don’t have a charge, neutrons should be compatible with matter and anti-matter.

Correct me if I’m wrong, please _

I would have thought so, too, but it’s not the case. It’s not just about charge of the particles. I should probably read more about it since now I’m wondering some other things.

It seems that when physicists talk about matter/antimatter annihilation, it’s always in mirrored pairs. A positron annihilates an electron; an antiproton annihilates a proton, etc. What happens if a positron meets a proton? I mean, I would assume that mutual annihilation is not the outcome, since a proton is much more massive than a positron, but…what then?

Also interestingly, while Wikipedia agrees that this process is far more powerful then the second-best power source (nuclear fusion) it notes that the process of mixing protons with antiprotons results in 74% of the energy eventually turning into neutrinos, which have no practical use in energy production. Therefore, the theoretical efficiency limit of antimatter propulsion is only 26% (but actually less due to heat loss) but with the huge amount of energy created in the first place, that’s still pretty powerful.

Jul 03, 2012 at 01:18AM EDT
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Piano wrote:

and , with a composite system of , are considered seperable states. But in the form of is seperable if yielding and . It is inseperable if .

I…actually understand what this means. Entanglement is a bitch.


On the topic of antimatter:

There are certain particles which are their own anti-particles; photons, for example. Neutrons are actually composite particles, consisting of one ‘up’ and two ‘down’ quarks. Antineutrons consist of one ‘anti-up’ and two ‘anti-down’ quarks. In that way, neutrons and antineutrons share properties, but some have reversed signs (such as baryon number and magnetic moment).

Antimatter propulsion is…far-fetched to say the least, I think. Antimatter is so unbelievably expensive and difficult to create that it would be impossible to create enough to power anything. And even if we could, we would have no way to contain it. At all. Ever. It would immediately annihilate with any normal matter it encountered. There was a paper recently about the fine structural analysis of the anti-hydrogen atom, in which the researchers had managed to stabilize a (very, very, very) small number of anti-hydrogen atoms for a (very, very, very) small fraction of a second (on the order of milliseconds I think). This was seen as a huge advance in the study of antimatter, so you can see that we have a very, very, very long way to go if we’re ever going to be able to use antimatter as a fuel source. In my opinion, it won’t happen.

Last edited Jul 03, 2012 at 01:45AM EDT
Jul 03, 2012 at 01:35AM EDT
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opspe wrote:

I…actually understand what this means. Entanglement is a bitch.


On the topic of antimatter:

There are certain particles which are their own anti-particles; photons, for example. Neutrons are actually composite particles, consisting of one ‘up’ and two ‘down’ quarks. Antineutrons consist of one ‘anti-up’ and two ‘anti-down’ quarks. In that way, neutrons and antineutrons share properties, but some have reversed signs (such as baryon number and magnetic moment).

Antimatter propulsion is…far-fetched to say the least, I think. Antimatter is so unbelievably expensive and difficult to create that it would be impossible to create enough to power anything. And even if we could, we would have no way to contain it. At all. Ever. It would immediately annihilate with any normal matter it encountered. There was a paper recently about the fine structural analysis of the anti-hydrogen atom, in which the researchers had managed to stabilize a (very, very, very) small number of anti-hydrogen atoms for a (very, very, very) small fraction of a second (on the order of milliseconds I think). This was seen as a huge advance in the study of antimatter, so you can see that we have a very, very, very long way to go if we’re ever going to be able to use antimatter as a fuel source. In my opinion, it won’t happen.

Ah, okay then.

BACK TO MARS COLONIES!

What would happen if, say, China, Russia, or Japan put their own colonies on mars as well I’m assuming that diplomatic decisions of territory lines would be made. What happens if someone breaks the rules? Do the colonists fight or do we fight on Earth?

Jul 03, 2012 at 05:29PM EDT
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Brucker wrote:

That’s something I’ve never understood about sci-fi stories such as “Star Trek” that use antimatter as a source of energy.

He’s right that you get incredible output of energy out of just a tiny bit of starting material, so even though physics says we can’t manage 100% efficiency, it hardly matters as you’re dealing with huge amounts of energy. A gram of matter broken down entirely into energy is equivalent in power to over 500,000 gallons of gasoline/petrol. While this sounds great, there are two big questions remaining.

First, where are you going to get antimatter to fuel your ship? It’s certainly not lying around waiting for us to pick it up and feed it into the fuel reactor. You’d either have to find some way out in space (in which case we still have the same problem of how to travel with less-efficient means) or you’d have to manufacture it. But while scientists have methods of manufacturing antimatter, it takes more energy to make it than you get from using it. (Producing antimatter costs scientists about $25 billion per gram.)

Secondly, and far more important in my mind, is the question of storage. What exactly is your “gas tank” going to be made of? Whatever kind of vehicle you use anywhere in any circumstance, you need a container to store fuel reserves that is made of a substance that will not react with the fuel and make it unusable. So what is that for antimatter? Well, it can’t be made of any “normal” material, because the antimatter would annihilate itself and its container. If you could make a container out of antimatter, you still need to figure out how to store that container safely. Certain methods have been explored, and the folks at CERN have managed to create about 300 atoms of antihydrogen, some of which they were able to hold in storage for a little over 15 minutes before they were annihilated. In other words, we’ve got a long, long way to go before we can fuel a ship in this manner.

That’s what I’ve always known though, and by this logic I’ve believed that anti-matter production and storage is impossible.

Jul 03, 2012 at 06:16PM EDT
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Pseudogenesis wrote:

Anybody wanna talk about XNA? I wanna talk about XNA.

Intriguing. What do you want to discuss about it?

I’m finding it rather interesting that XNA works like DNA, but isn’t DNA. People tend to get nervous when scientists mess around with DNA, but this is something else entirely. Does it interact with DNA? Could one replace the DNA in one’s body with XNA strands that carried the same code sequences, and if so, what effect would that have?

Jul 03, 2012 at 08:43PM EDT
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Relevant to thread:

Last edited Jul 03, 2012 at 08:47PM EDT
Jul 03, 2012 at 08:46PM EDT
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Brucker wrote:

Intriguing. What do you want to discuss about it?

I’m finding it rather interesting that XNA works like DNA, but isn’t DNA. People tend to get nervous when scientists mess around with DNA, but this is something else entirely. Does it interact with DNA? Could one replace the DNA in one’s body with XNA strands that carried the same code sequences, and if so, what effect would that have?

I’ve done a bit of research, and here’s what I’ve got:

Does it interact with DNA?

Yes, it can. If a gene is synthesized that interacts with DNA, then that will happen. XNA behaves like DNA in that it self-replicates and evolves. XNA also stores genetic information, as DNA does.

Could one replace the DNA in one’s body with XNA strands that carried the same code sequences, and if so, what effect would that have?

No. XNA synthesis is only possible in vitro. Therefore it is impossible to ‘replace’ DNA with XNA inside an organism. However, since XNA behaves like DNA, it could be theoretically possible (although not currently) to create a synthetic lifeform. What this means is that it could be useful for creating organisms to counter certain viruses or bacteria, but there are a huge number of ethical issues associated with this. The authors of a paper in Science from a few months ago (DOI) state that they are going to pursue more advanced gene synthesis to develop better catalysts for use in biotechnology and medicine.

Jul 03, 2012 at 09:47PM EDT
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sting_auer wrote:

2.) If we use fusion powered thrust, the time to get to mars is shrunk down to a few weeks. Fusion can already be done with modern technology (We can sustain fusion for a few minutes at a time, IIRC), doing it on a spacecraft designed for the task wouldn’t be that much of a stretch.

I’d say that’s actually a pretty giant stretch. I visited the JET research labs a few years back, where they’re currently working on fusion reactors. According to the guys working there, we’re not even close to solving fusion. Their biggest problem is containing a fusion plasma for long enough for the energy output to surpass the energy used to start the reaction in the first place (once it starts it’s self-sustaining, unless containment fails). Fusion plasma is seriously energetic, and it only takes a tiny amount of plasma to escape the magnetic containment fields to make the entire reactor shut down. They also have huge problems with heating the gasses up in the first place, since it’s pretty hard to inject energy into a system you’re trying to isolate from all other matter (I think they currently use a particle accelerator to shoot the fuel into the vessel at ridiculously high speeds, but it’s not a perfect system by any means). Finally, the ingredients required are fairly hard to come by, and are currently pretty expensive (though if they started producing it in huge bulk for this purpose I imagine the price would fall significantly). It’s still probably a lot easier to get deuterium than enriched uranium, but uranium is currently much more useful for power generation.

They’re moving most research to the new ITER research centre in France soon, since it turns out that our reactor vessels aren’t anywhere near large enough. That’s expected to run for over a decade collecting data before they’ll even think about using fusion as a viable power source. Right now it takes way more energy to start up a reaction than we could ever hope to retrieve from it.

From there, who knows what kind of obstacles we might face? I don’t think it’ll be as easy as simply figuring out fusion and then suddenly we can use it to power rockets. Fusion reactors are very large, and very fragile (any small bumps may disturb the plasma inside), so it wouldn’t be as easy as sticking a reactor to a rocket ship and flying off to Mars. We’ll be stuck with conventional rocket fuel for a long time still.

Last edited Jul 03, 2012 at 10:43PM EDT
Jul 03, 2012 at 10:42PM EDT
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The fusion powered rocket engines don’t sustain fusion, they just cause fusion for an instant and let the resulting gasses shoot out the back to create thrust.

Then, they create fusion for another instant.

then another.

It’s essentially a fusion-powered pulse jet.

Jul 03, 2012 at 11:30PM EDT
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Brucker wrote:

Intriguing. What do you want to discuss about it?

I’m finding it rather interesting that XNA works like DNA, but isn’t DNA. People tend to get nervous when scientists mess around with DNA, but this is something else entirely. Does it interact with DNA? Could one replace the DNA in one’s body with XNA strands that carried the same code sequences, and if so, what effect would that have?

Haven’t looked into it too much, but I’m definitely willing to. Apparently it’s genetically isolated from DNA and RNA, so it can’t assimilate and get “Out of control,” like some scientific alarmists might fear. This isolation makes it useful for genetic experimentation, since it behaves exactly like DNA, but runs in an entirely parallel vein due to using different sugars as its backbone. I just find it remarkable that scientists have been able to create a self-replicating material entirely from scratch. And the fact that it’s apparently been around for a few years? Why haven’t I heard about this sooner?

Last edited Jul 03, 2012 at 11:50PM EDT
Jul 03, 2012 at 11:49PM EDT
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If newtons laws of relativity and Einsteins laws of gravity hold up, the downward force of the people and the density of oxygen could in fact lead to sustained flight.

Jul 04, 2012 at 12:48AM EDT
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Twins the Serendipitous Serval wrote:

How about dem retroviruses? These are really, really scary. They insert themselves into DNA and are replicated with your genome forever. They bloody make up 8% of the entire human genome, lying dormant, ready to go off at a moment’s notice.

Yeah…retroviruses are nasty. Look no further than HIV. And apparently it’s believed that they’re involved with Multiple Sclerosis. They aren’t all bad though; currently, some retroviruses are being used for gene therapy, and XNA may be able to improve on this.

Treating malignant retroviruses isn’t easy. The best approaches we have are protease inhibitors, which tie up active sites within the viral enzymes:

As a chemist, I can say that my biochemist cousins are constantly working on new and better ways to inhibit such enzymes, so that things like HIV can be stopped.

Now, about endogenous retroviruses, since they’re incorporated into the human genome (or genome of the host organism, whatever that may be), once again gene therapy might be able to be used in the future. For the most part, they are benign, but their involvement with autoimmune diseases is being investigated. Some studies have even linked them to schizophrenia. Treating this with gene therapy may be possible in the future, but it would need to be done in utero, which again raises ethical questions, so it probably won’t happen anytime soon.

Jul 04, 2012 at 01:40AM EDT
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Dac wrote:


If newtons laws of relativity and Einsteins laws of gravity hold up, the downward force of the people and the density of oxygen could in fact lead to sustained flight.

Nah, because when “Person 2” pulls up for the first time, they’ve got to pull both for themselves and for the other person. This basically means that, because of the “Equal and opposite force” law (Can’t remember which), you’d just end up on the ground because you’re lifting the other up.

Or maybe I’m just taking troll bait, what the fuck do I know

Last edited Jul 04, 2012 at 01:45AM EDT
Jul 04, 2012 at 01:45AM EDT
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Pseudogenesis wrote:

Nah, because when “Person 2” pulls up for the first time, they’ve got to pull both for themselves and for the other person. This basically means that, because of the “Equal and opposite force” law (Can’t remember which), you’d just end up on the ground because you’re lifting the other up.

Or maybe I’m just taking troll bait, what the fuck do I know

Umm…. I wasn’t serious. I’m not a moron dude.

Anyways, what do you guys think is beyond the event horizon of a black hole?

Jul 04, 2012 at 01:53AM EDT
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Dac wrote:

Umm…. I wasn’t serious. I’m not a moron dude.

Anyways, what do you guys think is beyond the event horizon of a black hole?

A singularity.

Jul 04, 2012 at 02:02AM EDT
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Brucker wrote:

That’s something I’ve never understood about sci-fi stories such as “Star Trek” that use antimatter as a source of energy.

He’s right that you get incredible output of energy out of just a tiny bit of starting material, so even though physics says we can’t manage 100% efficiency, it hardly matters as you’re dealing with huge amounts of energy. A gram of matter broken down entirely into energy is equivalent in power to over 500,000 gallons of gasoline/petrol. While this sounds great, there are two big questions remaining.

First, where are you going to get antimatter to fuel your ship? It’s certainly not lying around waiting for us to pick it up and feed it into the fuel reactor. You’d either have to find some way out in space (in which case we still have the same problem of how to travel with less-efficient means) or you’d have to manufacture it. But while scientists have methods of manufacturing antimatter, it takes more energy to make it than you get from using it. (Producing antimatter costs scientists about $25 billion per gram.)

Secondly, and far more important in my mind, is the question of storage. What exactly is your “gas tank” going to be made of? Whatever kind of vehicle you use anywhere in any circumstance, you need a container to store fuel reserves that is made of a substance that will not react with the fuel and make it unusable. So what is that for antimatter? Well, it can’t be made of any “normal” material, because the antimatter would annihilate itself and its container. If you could make a container out of antimatter, you still need to figure out how to store that container safely. Certain methods have been explored, and the folks at CERN have managed to create about 300 atoms of antihydrogen, some of which they were able to hold in storage for a little over 15 minutes before they were annihilated. In other words, we’ve got a long, long way to go before we can fuel a ship in this manner.

As Sting_Auer said lower down in the thread, you can store antimatter with matter materials: by suspending it magnetically in a vaccum. And as for antimatter being created, I definitely see your point. Is it possible that we could harness the forces of, say, a star’s nuclear fusion, or a black hole’s singularity, to create antimatter? This reminds me, I remember seeing an article in Scientific American about how stars create antimatter at their core, which may be the cause of early supernovae.

It would, of course, be extremely difficult to extract antimatter from a star’s core, but it goes to show that antimatter could be created more easily than one is lead to think, and could very possibly be waiting for us in natural deposits.

Last edited Jul 04, 2012 at 02:11AM EDT
Jul 04, 2012 at 02:10AM EDT
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Dac wrote:

Umm…. I wasn’t serious. I’m not a moron dude.

Anyways, what do you guys think is beyond the event horizon of a black hole?

It’s a crazy question, because once you go beyond the event horizon, every theoretical measurement basically becomes infinity, which is a physical impossibility. Black holes are essentially the point at which everything we think we know about physics breaks down, which is what makes them both so irritating and so fascinating for physicists.

Jul 04, 2012 at 02:18AM EDT
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Skeletor-sm

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