Next Big Future’s Roundup of Tech Items Tuesday, Mar 31 2009
technology 5:03 pm
Read Next Big Future‘s overview of technological advancements in weeks 7-12 of 2009.
To my mind, what is most interesting here? The nuclear space cannon, an original invention of the blog’s author, Brian Wang. This idea has changed the way I think about space, but I still think that the political obstacles to nuclear explosions of any kind are too great for it to be viable.
What matters is the payload. Definition of an unmanned scientific observation spacecraft is easy compared to the manifest of a space colony supply ship. Should the cargo holds be filled with toilet paper or the machines to make toilet paper or the machines to make the machines that make the toilet paper?
I and Joseph Friedlander are looking at the issue of high-g acceleration and how much payload and keeping a large projectile together.
Ram accelerator work provides info on static and dynamic loads on space cannon launch. One thing is that the highest stresses are only acting for a short time. So you could go past ordinary measures of strength of material. Current navy guns can shoot large projectiles to put thousands of Gs of acceleration and the projectiles are not made of heroic material.
The Project Orion model does use boron and other filler as the propellant that gets converted into hypersonic gas and plasma. So it is not the nuclear blast that directly accelerates. The blast acts on the propellant and filler.
Can dig several miles deep to get to 1000g of acceleration if the propulsion can be made uniform across the distance. For more development effort can have underground Orion acting over a long tunnel. [David Brin idea. under and along the slope of Mt Kenya.] Could get down to 100gs. Make adjustments for low slope. The One shot cannon has advantages and simplicity. Analyzing and determining how well it can work.
Hopefully get enough interest for detailed computer analysis to be done. There has continued to be interest in the regular project Orion. This would at least be an improvement upon that. Even high-G launch from the north pole would reduce in atmosphere blasts from 200 to about 20 or less.
Once you have any reasonable level of space capability and can go to the asteroids then you can bring an appropriate sized rock back and drop it into the earth’s gravity well and rain destruction upon people down below. Like climbing out the valley and starting avalanches.
Even the robotically flown solar electric sail could do this. A bunch of long charged wires.
http://nextbigfuture.com/2008/09/solar-electric-sail-developments-and.html
We are not safer locking ourselves in a constantly more crowded room (earth bound with crazies with weapons). Some people can talk about sustaining the locked room condition. Reducing population growth and some talk about reducing population (letting people die or killing them). Those plans are stupid and unethical if they were put into action.
Is it safer to spread out: Yes. You will still have to care about what others say and do, but the strategy is the same as when machine guns and cannon were invented. You do not stay in straight line formations with swords and shields anymore or muskets. You have to spread out or you go mowed down with one volley or with one bomb. You must still pay attention and stay engaged and aware of what is going on. In the case of spreading out in the solar system, the laws of physics ensure that you will have more seconds, minutes, hours to do something and with proper design days and perhaps years. But you still have to be ready. The really extra time involves using metamaterials or other stealth material to stay hidden, much like the nuclear submarine force now.
Next Big Future is a great restorative, if you ever begin to think that the future is nothing but economic and environmental crisis. There really is a lot of other stuff happening in the world. :-)