Engineering

Hello, stone collectors and everyone! Moon rocks help understand our world, but all we have are meteoroids and 382kg of samples quickly collected from 6 small sites by the Apollo missions http://en.wikipedia.org/wiki/Moon_rock so a mission to bring back Moon samples from new sites would be exciting. I propose here a script to prospect many sites - including at Moon's far side :good: - taking the time needed to explore larger areas and pick the best samples. We don't need six Saturn-V for that goal because robots exist now and my sunheat rocket engine changes the game http://www.scienceforums.net/topic/76627-solar-thermal-rocket/ so one middleweight launch suffices. --…

Superb craftsmanship worth sharing. Enjoy : ---->

This is a sister to my first topic: http://www.scienceforums.net/topic/108036-moon-explosion-and-radiation-for-sci-fi-book/ In my story, a major explosion sets humanity back in technology, and there is a major explosion on the moon. It could be the moon explosion that generated an EMP, or it could be a major solar flare that generated the EMP on earth and also caused the moon explosion. I'd prefer to have it all caused by the moon explosion (NEMP). If the explosion has to be nuclear, that fits my current idea as to why it happened at all. But here I want to ask another question. For my story it is important that the EMP bursts continue several times each da…

working-in the normal state(no cracks) no emf is induced in secondary coil.when crack is there the magnetic flux changes hence emf is induced in the secondary which turns on the thyristor and hence buzzer.will this circuit work as intended

I saw a youtube video of RC planes. What if engineers would invent RC real airplanes for transportation? What is your view in this suggestion?

I'm not entirely sure where this should go but this seems like the right place. I've been watching a bunch of hoverboard videos lately. I mean the Hendo and the Lexus ones that really hover on electromagnetism. I know these need to hover over a special surface like copper to make the magnetic wave repel and lift, what I don't understand is what happens if you attach the metal surface to the hover engine device. Like something as simple as taking a thin sheet of the metal, hooking it on a cord tied to the hover device, and then let the hover device repel against the metal or simply being in a box with one end the magnet and the other the opposing surface. Does the ma…

The ISS cost a lot of money, I've seen estimates as low as 100 billion and as high as 400 billion. I've also seen arguments that it wasn't really worth it. I was just wondering why we didn't spend that money on a Star Tram. Right now, current rockets cost about $18000 per kilogram of payload. Space X, with their reusable first stage rockets, could bring that down to as low as $1200 per kilogram. I also learned about the Star Tram and on their site they claim that it could bring the cost down to $40 per kilogram. The site claims that the Star Tram can be built with known technology and materials unlike the Space Elevator. The Space Elevator gets so much attention even …

Any thoughts on the feasibility of using a sail kept aloft by balloons rather than a traditional mast?

So, I was on the website known as 4chan, lurking at some posts on /sci/ (the board is called "science" just in case ya'll don't know.) and trying to find something interesting. When I suddenly found myself looking at this picture of how telomeres work and why they're the reason we age. So i ended up asking myself... how do we slow or stop telomeres from shortening? Here's the post if ya'll want to see (hope it didn't 404 by the time you see it -.-): http://boards.4chan.org/sci/thread/9069182 So, I found myself searching how to do what I'm asking when I come across a study from Harvard. Here it is if you want to see it: http://newatlas.com/telomerase-aging-h…

I was thinking about all the excretions and body fluids that end up in sewage and thought "Bacteria and oxygen might do it for less cost but it is less efficient than my method" So here is what I was thinking. At some point in the pipes there is a poop catcher and right next to it a valve that will only open when there is no fluid. This diverts the poop to a different set of pipes that eventually leads to making a human poop biosolid. Meanwhile, the rest of the fluid continues on through a series of 7 filters each designed to catch something you don't want in the water and is microscopic. The first filter blocks cells(so blood cells, bacteria, fungi, protozoa, endot…

Hello, I'm a person who is in her mid teens and wants to understand and make it possible for human kind to fly. Im fully aware of lots of problems with this like how would we connect our nervous system to the wings, would the brain even intake it? And our body mass is much too large I'm very aware on that I also know most people have tried very hard to make it happen I'm simply one who shall carry on that legacy and hope to makeep it happen (:

So my friend and I were walking in the rain yesterday. And obviously we had our phones drenched. Mine worked fine but hers didn't. After a while when we went back home and her phone started to work again, she told me that she had kept it in a rice container for a while and it started to work again.Now she may be lying and I'm aware of the water absorption capacity of rice, but does this even work like this? Is this some life hack we're all supposed to know?

HELLO EVERYONE, HEREBY I ENCLOSED THE PICTURE OF THE BLOCK. I WANT TO FIND THE DEFLECTION ON BLOCK AT 35mm FROM GROUND DUE TO 2x M12 SCREWS WITH TORQUE 120Nm. I FOUND PRACTICAL DEFORMATION AS 0.011mm. BUT I COULD NOT GET THE THEORETICAL SOLUTION FOR THIS PROBLEM. PLEASE ANYONE HELP ME TO GET THEORETICAL DEFORMATION. THANK YOU, REGARDS VARATHA

In analyzing the discussions on coin tosses we have going, I came across a question that might have derailed the other threads, so I'll open it here. Persi Diaconis had Harvard engineers build him a coin-flipping machine for a series of studies. Apparently the device could be adjusted to flip either heads or tails repeatedly. I assumed the next natural test would be to see if the machine could be calibrated to flip a coin on its edge every time, but I couldn't find anything on that. How easily/cheaply could a device be made that flips a coin onto its edge (virtually) every time?

High my name is Donar Craigie on YouTube I have a detailed description. You are correct more torque is needed to create speed, but I have done an experiment to show that constant torque can increase in speed against the same wind pressure. It is the principle of moments the torque is held constant on one side by increasing the distance [that is the blade side you would say] while the load is increased on the other side of the pivot without increasing distance, so the torque increases to compensate for the increase in speed on the blade side. For instance the pivot is at 50cm, the load is at 0cm and for the first trial a large light plastic plate is at 75cm which is 25cm f…

The riots in Hamburg Germany, for the G20, shows an army of riot police in very heavy clothing, helmets, and facemasks. It is also a hot summer day. The news made no mention of cooling systems inside the clothing of the riot police. How expensive would it be to wear a cooling system?

Why use highly complex rocketry and satellite guidance? If a terrorist wanted to get the job done...well you get the picture. I would think if this were somewhat feasible, it would have happened somewhere or at least been thought of. So my question...is it possible? ~ee

Since we are on the topic of grenades I thought up of a grenade with 360 degree cameras and a gun which when thrown into an enemy trench would randomly pick a path through the trench until it runs out of bullets or batteries. Would this work?

Why does this never get invented? The problem is car cabins can get VERY hot when parked under the sun. The temperature inside a car can get so high it will kill any babies or pets accidentally left inside the car. Even an adult will die inside a closed car in the hot sun, if they are unconscious or disabled. Also, it is very uncomfortable to start a very hot car. All it takes is intake fans in the floor of the car and exhaust fans in the ceiling, and the fans are powered by solar cells on the roof of the car. This would ensure that it could never get hotter inside the car than it is UNDER the car, in the shade, (because that is where the air intake is). Nobody …

Some time ago I saw articles, most probably from car manufacturers, describing the ideas/wishes of some, to use hydrogen as fuel for their internal combustion engines, if the economies turn to it as energy source and thus satisfy the environmental requirements. In my opinion it's not only the environment that has to be protected it's an economical matter too. Internal combustion engines can't get away of an overall efficiency in the low thirties while fuel cells climb to 80%. Huge difference. We understand how admirably the engine manufacturers have perfected them during the past 100 years or so, but they have to do the same with fuel cells and a lot faster,…

warning..this post is going to have some serious ignorance attached to it so I get that the chronology is vacuum tubes > transistors > IC's.... I remember seeing an illustration of a vacuum tube. It had a battery/ power supply connected to the VT. The VT conducted electricity and then sent signals throughout the computer. Why even have the power source (wall outlet basically) connected to the VT, and just hook up the power source up to the computer directly, with little logic gates to get it work send 1's and 0's? ~ee

Hi. Trying to find if there is in the market a mechanism that holds a string under pulling force by pinching and releases it by a solenoid or lever. Or an off the shelf device/gadget that can be re-purposed. String wound ------------------------pinching mechanism------------------------>20 Newton pulling force in a bobbin ^release solenoid^ Have you seen such in everyday items ? Sort of clothesline extender, window blind or something alike... Just trying to reuse instead of re-invent/design. If possible plastic, or non-corroding. Not self-rewinding as a measuring tape.

Hello everybody I'm from Iran and I have an urgent question, I want to find username &password of scientific University such as New York University and McGill and the other famous universities. Pleeeeease help me about finding MD accounts, If you don't have any information about my question, please introduced some forums or sites that they are selling or sharing these accounts... Thank you

It's a rather dumb question, but here it is: My thought of the major factor in efficiency between the two turbines is the amount of variation of temperature within the engine itself. *Does this hold true?* Here's my theory: The more consistent the temperature, the higher the efficiency. Gas turbine: Combustion of gases would have a slightly more temperature fluctuation due to occurrence of incomplete combustion of gases. Steam turbine: External source of heat constantly maintains gases' kinetic energy, keeping the heat consistent. Also water has a higher specific heat. Therefore, the steam turbine would theoretically be mo…

Global Positioning systems are extremely accurate typically <10m, assuming there is good satellite coverage. Satellites have both high and low orbit, Inmarsat coverage is particularly poor. I would like to start a discussion ref the reliability and accuracy of the various GPS networks. I am particularly interested in how the accuracy, or time, of the clocks may be affected if they are in different orbits around the planet, or at different altitudes or orbiting in different directions. For example if in orbit around the equator, at higher latitudes or perhaps orbiting over the poles. The reason the question occurs to me is that I use GPS in navigation off sh…