Engineering

So there are several ways we could get off this rock, and also several ways to travel somewhere once we do. Which practical method is your favorite? I think for liftoff I would prefer a launch loop for the absurd cheap launch capacity from ground-based electricity. Alternately, a nuclear lightbulb, for its high specific impulse and flexibility. Or Project Orion (no relation to the shuttle of the same name) for the awesomeness factor of being able to lift an entire city, if people didn't mind nuking the atmosphere while sitting on a pile of nukes, and also the only craft I am aware of that could both lift off and travel to another star. For traveling after lift-off…

which would use up less energy, going up the stairs one at a time or two at a time?

Hello! Here is a topic that maybe hot on our tails in about 50 years, AI. Okay first for AI to come to life we need full knowlege of the human brain, this includes emotions, thought, institinct and so on. 2nd we need enough computing power to code the complexity of the human brain (we would start small e.g mouse) in a "robot". Now i will discuss how the second aspect could be plausable in 50 year. We are now developing quantum computers, these computers are at their developing stage. About a few years ago 7 atoms figures at 5x3=15. Now that might not seem much but we are only talking about 7 atoms seen as there are millions of atoms in a mm we are talking abo…

If it is possible to do this As intecatly as this http://www.youtube.com/watch?v=t2sCCN3tpp0 There are even multiple open source designs for such machines. And we can use metal powder as well as plastic powder and filler powder (which we can). Then what is the problem with giving such a machine it's own design and letting it make a copy of itself? It might need a folding part or to be built in two parts as to obay the laws of size. Such a machine is reliant on energy but should be able to make it's own supply structure. The only things it would need from outside would be plastic, filler and metal powder and an electricity supply or materals to har…

Well I must say the technology we have now there is not much we can do.The TV shows that shows how to destry a asteroid the technology we have will not do that.

Suppose, there's a shorted coil which has a wire resistance R. Also, current i is flowing through the wire. Then, my book is saying that flux linkage "lamda" satisfies the equation " - i R = d(lamda)/dt "

Hello all, I was looking at a corn field not long ago and thinking about the optimal shape of the field's surface to maximize yield. Why do we keeps fields flat ? If instead one were to shape them with hills and valleys, say as a sine wave, the net surface area would be much more than the surface of a flat landscape - that would make for more space to grow cucumbers, salad, carrots ... Of course the wavelength of the sine wave should be greater than the average size of the plants grown, so the vegetable themselves wouldn't "fill the holes". Although, the hills shouldn't be too steep so they wouldn't cast too big a shadow. What do yo think ? McCrunchy

Im looking for a material that can achieve a moldable, low viscosity liquid phase and then solidify into the shape i want. It has to be transparent, able to absorb... or hold... water, highly gas permeable, and biologically inert. We've experimented with Nafion, various RTV Silicone rubbers, and agarose. Anyone have anything else that might come to mind? Just looking to broaden horizons here

BIT01 wrote:As all of you know I am trying to build a hovercraft. My problem is that I need to know how much air I can pump into it to run correctly. Any formulas and assistance will be great. Thanks.

The TV shows star treck and star wars that show those big space ships or SSTO make me laugh. No propulsion system today allows SSTO like those scfi shows. May be in 20 years from now we may get a very very very small crude SSTO but will be nothing like the scfi shows.The big problem is propulsion and that is why we must use stages not a SSTO .There has been some work on very small crude SSTO but even than the propulsion does not allow it. Why will the scfi shows not get it right?

What do these symbols mean in electronics? [math]V_{DDH}[/math] [math]V_{DDL}[/math] [math]V_{SSH}[/math] [math]V_{SSL}[/math]

http://en.wikipedia.org/wiki/DEMO DEMO is a power plant whose conceptual design is set to be completed in 2017 (following lessons learned from ITER) and construction set to complete some time around 2033. The goal of the power plant is to continually produce approximately 2 gigawatts of electricity, and demonstrate the practical feasibility of fusion power as an energy source.

A question has been prompted in my mind, from another forum ( guitars) about the 'feel' (tension) of guitar strings: If two pieces of wire with the same diameter but made from different alloys (bronze and phosphor bronze) are brought to the same tension (pitch), would there be any difference (everything else being equal) in the amount of pressure required to move them laterally ie press them down on to the fret? I don't think there is because metals don't have longitudinal elasticity.....what's the fact?

I have been asked to design a system to measure the force being applied to the working face of a system. Basicly it is a class two lever and i want to measure the force being applied at the load point. The image below shows the object where the load is being applied. The load is applied to the inner face on the left hand side. Can someone suggest a location where I can find information on how and where to attach strain gauges to measure force on such a face?

I'm new to this forum but I'm a science geek. Sorry if this is way off topic for your forum but I thought this would have enough science involved to ask this question and hear an intelligent debate. The car in question is a MR2 Turbo. To cool the engine bay on a MR2 turbo there is the radiator mounted up front and passive cooling over the motor; Air rushes under the car and out the vented engine bay hood. The conflict is that a common modification to the car is putting two 11 inch 850CFM fans under the hood vent. My personal hypothesis on this is that the fans would restrict air flow because they can only move 850CFM thus a limited RPM. A sales rep. told me …

Hi: Which method of radio transmission/reception for wireless computers is more secure -- Frequency-Hopping Spread Spectrum or Direct-Sequence Spread Spectrum? I believe the former is more secure than the latter because it does not constantly remain on the same frequencies. Am I right? Thanks, Green

I'm about to take a vacation to another country, and I'm worried about getting mugged and robbed. I've been hearing recently about a rather new piece of technology that is designed for just this sort of thing. It's called the Technobra, and it notices a jolt in your heart rate and uses GPS and wi-fi technology to alert the authorities of your name and location, so that they can find you anywhere in the world. The problem is: I'm a guy. Is there any kind of this technology that I can use on my vacation?

hey, i want to make a RC helicopter from some old RC cars i used when i was young. some of them go pretty fast so im pretty sure it can get off the ground with one of the engines or whatever moves the wheels on the car. i dont know much about building an RC helicopter though because iv only taken apart the cars and i dont even understand them much. i need help with pretty much everything, what turns and rotates the helicopter, how to make the battery i want run the engine i want, how to make the controller i want work with the car parts i take. im not sure how close i can get to a RC helicopter befor i have to go to a store but if anyone knows links with useful in…

I want to build a home made electric RC Heli, very small and light. I have one of those Mini RC racers, like these and i want to convert one into a heli. They are powered by capacitors, but I don't know If the motor and all can produce much thrust. I can make prop blades out of nylon to keep it light. Does anyone have any suggestions, ideas, or even better; has anyone actually made their own electric micro heli? If it won't work to make it out of the car, what can I use? I want to use capacitors, because Li-Po batterie cost too much. What motor should I use, etc. Thanks for any advice.

Hi 1. What is the benefit of using Fourier analysis? 2. What is the difference between time domain and frequency domain? Regards

Hi all, Can you help me with this question ! What is the range of the frequency that is received by mobile phone? Thanks

How does the device briefly shown here inside a cabinet works ? http://www.youtube.com/watch?v=V1IfzVrNqtU&feature=related The output seems to be a detergent injected with microbubbles. How does the mixing produces the bubbles so small ?

My friends and I were thinking of building an air cannon, to play around with motion equations, and secondly, to have a blast by utilising it in various ways. The conceptual idea is pretty simple, a cylinder of pressurised air, connected by a butterfly valve to a relatively long, rigid PVC tube, which would act as the main barrel. We were then thinking to then mount our settup onto a a flat wooden base, and then simply add an axel, on which one could regulate angle. As I said, the idea's simple, but I thought to ask some more experienced members here, for perhaps some hints in regards to how to achieve optimum performance. Any thoughts?

you want to design a: 1-cannon that will blast an: 2-object as high as possible in the atmosphere, and again, reaching outer space is a bonus.. what are your ideas for 1 and 2?

any reason why it would not be possible to have two sets of blades on a turbine. one would be in front and would turn the first rotor clockwise and another would be behind and turn a second rotor counterclockwise.(no stator)so the relative movement between the two rotors is much greater than the movement for one rotor and stator in for the same wind blowing at it. the first rotor could have 3 blades like a standard wind turbine. the second rotor obviously is blocked whenever it is directly behind the first so it would have maybe six? (or more) so that some blades are always exposed. so the rpm of the standard turbine would be x rpm relative the rest of the turbine. …