Sure it has a higher specific thrust, but they still haven't solved the problem of getting enough electricity to run it on a spacecraft. You can't keep a fission reactor cool with nothing but black body radiation from the surface of the craft unless it has a huge surface area. If they shoot a huge laser at the craft, converting that to electricity is still going to have low efficiency, so you still have the problem of cooling. Obviously the high weight-to-power ratio of any kind of chemical battery would defeat the purpose and probably result in an overall system no better than H2/O2 rockets. The best they've got is betavoltaics and photovoltaics. 500 square meters of solar panels to produce 50KW at mars' distance.

>> ^jwray:
Earth has enough people on it; population growth must stop.

I agree to some point and I see it happening. In all developed countries birth rate goes down and approaches or even goes below replacement values (e.g. negative growth in Italy, Japan for example). So once a country reaches a sufficient level of development, population growth stops and further growth is not necessary for improved prosperity, advances in automation and efficiency will make these countries richer.

Now if me manage to help the developing countries develop, they will also level off. Because developed countries just don't need a lot of children to support themselves later in life. This will happen over a period where their population still grows rapidly, though increasingly slower. UN projection estimate that the world population growth will flat-line around 9-12 billion people. So if the Earth can support this population, were fine for the future, a very bright future indeed. I'm convinced the Earth can support this number with increases in intensive farming and technology, so more food production per acre, and by changing our energy demand and energy sources. That is develop large scale fission or fusion processes to power our more efficient society.

>> ^BoneRemake:
ya think one of you people with the colourful icons next to your name would of put a Long tag on this.

Read the FAQ and maybe one of these days you...yes you could be one of those people with "colourful icons". Or you could fuck up and get hobbled...that's actually what I'd do, chicks dig outlaws

>> ^RhesusMonk:
Question regarding fusion: If the binding energies of the two hydrogen isotopes equal 10 MeV, and the binding energy of helium is 28 MeV, wouldn't the fusion require the input of 18 MeV? I don't understand. Doesn't the helium require more energy to hold together than the hydrogen isotopes had to begin with? And, even if the nucleons do just come together, how is there surplus energy if less energy went into the reaction than exists in the product?


Ok, it's a long time since i even looked at physics, but i'm gonna study astrophysics next year so i better make at least an attempt

The electromagnetic force repels the nucleons from each other. The nuclear force attracts them to each other. You have to force the two together. That requires you to overcome the electromagnetic force. So you only need enough energy to do this, and the energy required to do this is usually LESS than the energy that is released for atoms 'below' iron.

The energy basically comes from a conversion of mass to energy. The mass of the combined atoms is not quite equal to the mass of the parts that you combine. Mass is lost, and it manifests as energy. (because e=mc^2, or in other words, energy and mass are 'interchangeable' - you cannot just 'lose' mass)

Thanks a Bunch!

In reply to this comment by gwiz665:
*quality *talks

>> ^dannym3141:

I suppose it's not all that strange really. Heat's pretty much the bottom rung of energy. Pretty much everything (?) that uses or converts energy creates heat as a by product. Heat is one of the side effects and wasted elements of a lot of systems. I imagine, it being on a low rung, it's no surprise that we have to through heat to go back up to anything higher up the ladder.
Badly explained


Yea, there is a free Nobel price in for anyone that can convert heat directly into electricity efficiently.

>> ^rottenseed:
You know what's funny...as technologically advanced as we are, fundamentally, all we're doing to get power is finding different ways to heat water and make steam.


I suppose it's not all that strange really. Heat's pretty much the bottom rung of energy. Pretty much everything (?) that uses or converts energy creates heat as a by product. Heat is one of the side effects and wasted elements of a lot of systems. I imagine, it being on a low rung, it's no surprise that we have to through heat to go back up to anything higher up the ladder.

Badly explained

>> ^swedishfriend:If we take too much mass from the moon we fuck up our entire ecosystem and climate since it is so heavily dependent on the pull of the moon's gravity...

Wow... do you even know how big the moon is? It's a little more than 1/4 of Earth's mass. As a species, we have dug up about .01% of the Earth's crust since industrialization. You honestly think we can do anything to the moon within the same timespan?

This is all ignoring the fact that digging further into the planet and in more remote locations is a fraction of the cost of digging into the moon.

Hey fission

I put up a new climbing video, thought you'd like to check it out, it's a good one.

http://www.videosift.com/video/Chris-Sharma-Climbs-Pachamama-A-Brutal-Hard-Route-in-Spain

Thank you for the promote, fission!

please, help these poor videos escape the queue

http://www.videosift.com/video/Mulatu-Astatqe-Yekermo-Sew
http://www.videosift.com/video/Dawn-Penn-You-Don-t-Love-Me
http://www.videosift.com/video/Dj-Mujava-Township-Funk
http://www.videosift.com/video/Brandon-Hardesty-Re-Enactment-Network
http://www.videosift.com/video/John-Wheeler-Pioneer-of-Nuclear-Fission-Quantum-gravity
http://www.videosift.com/video/Fucking-robots-yeah-someone-made-some
http://www.videosift.com/video/The-Rubber-Boy

>> ^notarobot:
I appreciate Brand's appeal for rational global-problem solving as well as his research and his organization of information, but I share almost none of his enthusiasm for the topics he discussed.
Genetic engineering presumes that humans, in our 50-70 year life span know better than nature. Nature has been at the game of shaping genes, of us and every living thing on the Earth, for a long time. Once a gene has been modified it can stay way for eternity. There is no undo. It is arrogant for any human to believe that even the knowledge of how to meddle with genes should be the same as carrying the wisdom to wield that knowledge without error.

If you think something shouldn't be done, because nature knows best, you could carry that same argument to all aspects of our technology, and I doubt you want us to live in pre-stoneage time again. I don't see how nature knows anything, or cares about anything. Nature just functions through mutation and selection. At any time an invasive or disruptive species could evolve. The only safeguard on nature is that evolution moves quite slow.
We have been genetically modifying animals since the first wolf was domesticated. Just look at what kind of freaky dogs we have created since. Or highly productive farm animals that couldn't function in the wild, a dairy cow for example. Now we have the ability to speed up and improve this process. And granted, there is a difference, because now we can move genes into an organism that never were there before, like jellyfish genes in a mammal.
Most if not all species that we engineer have no competitive advantage in nature and will only thrive in our carefully managed farmlands. For potentially more dangerous applications, we need to take adequate precautions and thoroughly test species or build in kill genes that we could trigger. Or just make them infertile.

Though it is true that warheads can be dismantled (with significant effort) for use in nuclear power stations, the fact that the bi-product of fission reactors is weapons-grade material remains lost on most people.

This fact is not lost on many engineers. Many modern reactor designs cannot make weapons grade materials. The reason that many old nuclear plants can do this is because they were specifically designed to make the bomb material and produce energy in the process.
Weapons grade material can also be made without reactors by extracting the fissile component of natural uranium.

Geo engineering is the product of similar arrogance of as genetic engineering. It is fueled by a desire for a static environment. The fact is that the Earth has never stood still, and will never do so (except for that one time in film..).

Of course the Earth doesn't care what we do, it and life will go on no matter what we do, even after a full out nuclear war. The point could be made that we have been geoengineering for a long time now. Just look at our cities, farmland and pollution. The only problem is that some of our geoengineering is potentially harmful to us and nature. Therefore deliberate geoengineering is proposed to mitigate these problems. From a humanitarian view one would want to mitigate these problems to relieve human suffering, just like we try to eradicate horrible diseases.

>> ^cybrbeast:
I couldn't agree more with this guy. He even talked about the evils of Greenpeace trying to stop Africa from using biotech. But that's only half of it, they are also against artificial fertilizer and pesticides. Probably responsible for the deaths of millions of Africans.
We need more rational environmentalists!


I appreciate Brand's appeal for rational global-problem solving as well as his research and his organization of information, but I share almost none of his enthusiasm for the topics he discussed.

Genetic engineering presumes that humans, in our 50-70 year life span know better than nature. Nature has been at the game of shaping genes, of us and every living thing on the Earth, for a long time. Once a gene has been modified it can stay way for eternity. There is no undo. It is arrogant for any human to believe that even the knowledge of how to meddle with genes should be the same as carrying the wisdom to wield that knowledge without error.

Though it is true that warheads can be dismantled (with significant effort) for use in nuclear power stations, the fact that the bi-product of fission reactors is weapons-grade material remains lost on most people.

Geo engineering is the product of similar arrogance of as genetic engineering. It is fueled by a desire for a static environment. The fact is that the Earth has never stood still, and will never do so (except for that one time in film..).

>> ^chilaxe:
I think we'd all prefer a Manhattan Project to set up next generation nuclear, solar, and batteries.

Too bad you've let nimbyists, special interest groups, and envirowackos tell you that recycling nuclear fuel is bad, and MOX is the DEVIL! Well that's alright, we'll take your plutonium up here in Canada, and Japan will take it too, and so will the rest of the world and use it as fuel. We aren't so picky. And you seem to hate the idea of pebble bed reactors, and you absolutely refuse to fund the next generation fission and fusion reactors.

Solar and batteries are a moot method of generation and storage. A better form of passive energy transfer, or capacitance storage medium will be the better option. On top of that, the best way to get "free" energy will be the beam it back to earth method via satellite.

lol... classic sift comments.

Not to 'feed the trolls' too badly, but to the last poster its dubbed 'climate change' for a reason, and have you not heard of global dimming, or metric tons of climate related research you just pretend doesn't exist? Oh wait, a dozen studies can be interpreted to agree with your views, while merely thousands very clearly disagree? yeah,... ok... obviously its a conspiracy and we're all sheeples... its the only logical answer!

And then the energy note... the many ideas you avoid include reducing current demand for energy (incentives to address energy inefficiency in homes and businesses, for instance), encouraging private power generation (incentives to install solar hot-water deal on the roof), and transmitting power from areas like offshore or 'wind belt' areas, high solar areas, etc. efficiently to neighboring areas via huge, buried, crazy-insulated cables. Anyhow, I acknowledge there are misconception about nuclear, but until fusion ushers in a new atomic age there are good reasons why Americans have repeatedly rejected fission power plants dotting the country... and if you don't know them and address them in your argument its odd to even argue for nuclear in the first place. I mean, would you not agree that China and France have histories of doing dumb shit in the past? So, yeah, an odd way to argue your point.