InigoMontoya

Umm... No. Pascal's Law. Learn it. Understand it, and you will understand why the volume of the tank has absolutely no influence on what the water in the pipes are doing.

You owe me a new keyboard!

And the bigger it is, the more difficult some of that maintenance will be... Show me the dry dock that can accept a 5000 foot ship! LOL. Maybe not. No way does this ship go through the Suez. As such, it likely never finds itself in their waters.

I lived on a ship for 2 years... I don't recall us ever having anything special to deal with lightning. I think it boils down to that whole *steel* ship floating in a bathtub full of salt water makes for plenty of grounding paths (IE, the ship itself is one giant, very well grounded lightning rod.).

I think they're going to run out of money long before they finish building their ship.

Huh? That's just a pic of me at the office (notice the white board in the background?). Granted, I work in a decidedly unusual office.

What would you call a spinning device that is driven by solar wind? I'd call it a solar sail turbine, but if you don't like that name, feel free to insert your preferred name for such a device. Alternatively, if you're saying that you are NOT describing some sort of generator set powered by rotating solar sails, then I apologize as there's been a misunderstanding somewhere. No, they can not be "as big as you want." And no, they can not be arbitrarily light either. In order to extract energy from the spinning device (whatever you want to call it), you have to exert a torque on that device. The larger the diameter of the device, the larger the stresses on all parts involved. That means that they DO have to have significant mass. True, that mass is still an order of magnitude below what an Earth-based system would be, but it's also a several orders of magnitude easier to throw that heavy Earth-based system on a truck and to the job site than it is to get that space-based system into a rocket and to LEO. Somebody on this thread already answered that: On the order of mW per square meter. Wrong. Mass (which drives weight) is a HUGE problem. You seem to be ignoring that you have to get this thing to space in the first place. Friction? OK, I'll grant you that one. Not that friction isn't real, but because it's such a minor part in this debate. As for the absence of gravity being energy itself? WTF? First off, being in orbit does NOT indicate a lack of gravity (quite the opposite, actually). Secondly, if this gizmo gets too big you're going to find that you're going to have all sorts of problems due to tidal forces. Third... The lack of gravity (even if it were true) is NOT an energy source. And the moment somebody starts using the Earth's rotational energy to generate a few PetaWatts, it WILL be a problem. Seriously, your statement is akin to somebody noting that a train doesn't slow down when a fly hits it's windshield. That doesn't mean the train isn't slowing down in general or that the fly didn't affect the train's velocity. Both statements are true. But the fly is so small that the effects are not easily measured. In sum: Yes, the Earth's rotation is slowing down.... But we're not going to notice any change in our lifetimes. So what? That's like saying you can drive from LA to NYC on a cup of gas simply because a cup of gas is enough to get you on the highway. What part of the law of Conservation of Energy are you not understanding? And if you don't understand the concept of the Conservation of Energy, I submit that you do not have the education to even begin to reasonably debate this topic.

In my experience (Defense Industry)... Getting published usually means one of two things.... 1) Having a paper put in as part of conference proceedings (after you present, of course). These papers are often pretty useless as they can often be summed up: "We did some really cool work in field XYZ, but we can't tell you about it right now because this is not a secure location. Here's my name/number/email. Call me if you're interested." In other words, it's a glorified infomercial. But if it gets you customers or more funding, it's time well spent. 2) Putting together a "Technical Memo" or "Technical Report" (depending upon length). This is typically not peer reviewed in the traditional sense, but pushing it through the process takes money so you have to have convinced somebody it was good enough work that they were willing to fund both the work and it's publication. The good news is that you can say whatever you want (but often don't because the red tape increases exponentially with increased classification). When somebody calls you as a result of your conference presentation, this is the document you give them as it has "real" information in it (although you can certainly put together a TM/R without doing a conference presentation). Patents are just what you think they are. As somebody else said, a good patent lawyer can get just about anything patented but defending that patent may be very difficult indeed. Two more comments on patents.... 1) Everybody is aware of the traditional patent where you have some new gizmo. There's also what's known as a "method patent." An MP is basically the patent of a process. The equipment may be old hat, but the application of the equipment is new. 2) There are some new, radically different patent laws. I don't know if they're about to go into effect or if they already have. I'm not a patent guy per se. I just know that about six months ago I was told that if I had any patent stuff in the near future to turn it in NOW because there were some new laws and things were likely going to be much tougher to patent in the very near future.

And that is quite patently a false statement. True, there may not be frictional forces, but to extract energy from the system, you must... Well, extract energy from the system. Where do you think that energy comes from? Your spinning blades. So even if your blades are spinning at Ludicrous Speed, the moment you start to actually generate power with your system they will quickly grind to a halt. UNLESS... You are constantly feeding more energy back into the system. A wind turbine does this by extracting energy from the wind (yes, the wind on the back side of a turbine will be slightly slower than the wind on the front side). Your solar sail turbine... Well, yes, it is getting energy from the solar wind, but the energy density is crap (as has already been addressed in this thread) so you're unlikely to be getting maintainable energy levels at useful levels.

But at what cost? Even if getting something into LEO cost 1/50 of what it does today... Even if you could get the exact same efficiency from your space based windmill.... you're STILL spending an enormous amount of energy to replicate what can be easily done on Earth's surface. And if it breaks, who's going to fix it? On Earth it's easy to just send a guy up to fix it. In space... Not so much.

It won't sound any more impressive than a leaf blower... Right until you turn off the leaf blower. Then it'll sound like fuel pump (assuming you're running one).

Whether or not the leaf blower acts as "forward motion" or as a typical compressor would depend largely upon whether you were running your combustor in what's known as "connected pipe" or "free stream." If connected pipe, no, it wouldn't. If free stream, yes, it would. However, understand that when you are safely subsonic (ie, not even into transonic regimes) and operating free stream you're not going to see any reasonable compression ratio. I mean, you might literally be talking about a 1.001 : 1 compression ratio. Oooo, that's power there! Keep in mind that while subsonic ramjets HAVE been successful, they're typically in the transonic regime - and even then performance sucks.

So let me get this straight.... You want us to do your midterm exam for you? There's a thing called "integrity." You might see if you can buy some on ebay because you apparently don't have any (and you desperately need some). In other words: GFY.

You've been hitting on this one repeatedly for a while and I'll be honest, I'm not about to wade through it all and do the math but... If you're half as convinced that it's cheap/easy as you've been saying, why not just build the damned thing?

Sounds great... So do you have any proposals as to how this may actually be done?

One would hope, but I can state that I have gone through a TSA "wipe" (or whatever they call it when they wipe everything down with a patch and shove it into the machine) with no incident knowing full well that I was contaminated (I'd gone straight from processing facilities to the airport and didn't have time for a shower) with non-nitrated-ester type explosives. I've also been with my wife when she was pinged in the same type searches for being contaminated with HMX. Granted, I would expect a 9/11 investigation to be more thorough than a TSA baggage/personnel wipe, but I still find it interesting and perhaps telling that my wife - who bought new clothes and such for her trip - "hit" while I did not. FWIW: I work in the field of ordnance testing. My wife's field is ordnance synthesis and forumulation.

Indeed. Plus, there are plenty of explosives out there that are NOT nitrated esters which would in turn make the likelihood of them being detected after the fact much lower.

Not likely. * While the copper might be fire-resistant it's still going to be very vulnerable to damage during the aircraft impact. Wires that have been cut aren't going to perform their intended function. * The wire may be fire proof, but the insulation is not going to be. Remove the insulation from all that copper and your system is going to have all sorts of electrical shorts in whatever remains. Could you encase your wires in ablatives or similar? Yes, but you just made installation that much more lengthy (time) and obvious (visibility). We're drifting away from my field, but ionized (read: very hot) gases are reasonably conductive and as such they would create a Faraday cage of sorts around your receivers. Think of the "black out" periods of space craft re-entering the atmosphere. The vehicles are bathed in hot, ionized gases that make RF communication with them problematic at best. You'd see the same effects inside of a fire. As a result, I'll venture that your RF-based detonators aren't likely to work. Another note: At the office we routinely do what's known as a "fast cook-off test." During a FCO we take ordnance items, hang them about 3 feet above a pool of jet fuel, and light it on fire. The test is designed to mimic what happens when a fire starts under the wing of a fighter on the deck of an aircraft carrier on a very bad day. Suffice to say that it generally doesn't take very long before the ordnance decides to do something pretty exciting all on it's own. Even when the items are coated with high temperature insulative materials.... We're talking much shorter timelines than the collapse of the towers. My point being that any pre-positioned ordnance system of a non-extreme design would have started malfunctioning (read: Boom!) in a chaotic fashion long before the towers collapsed.

No, but it *IS* difficult to get the explosives in question to blow up after they've been sitting in a furnace for 30 minutes or so after an aircraft impact. The odds of your remote control system - regardless of construction - being able to remain intact and functional after the impact and fire and all the damage that implies? Small. Very small. We aren't talking about a black box - a small object that can be arbitrarily hardened. We're talking about a network of detcord or wiring harnesses and the like strung all throughout the floor. You may be able to initiate such a system on *other* floors, but on the impacted floor using a system put in place in advance? I don't believe it. Disclaimer: And just as you are not an expert on demolition, I make no such claims of being an expert... I can, however, say that this morning I made just over two tons of 1.1 material disappear so it's not like I'm totally ignorant of the topic either. The collapse WOULD look different. Maybe not after the dust had settled, but *as* the building was falling? Yeah, it would look different. I'm not seeing the problem. Figure out who is in charge of building maintenance (or at least, one portion of it...say, plumbing) and who *isn't* you. Have that person killed execution style the night before you blow up the building. When the dust settles it will appear that the conspiracy guys killed their contact to keep him quiet and just like that... You're in the clear. I made a similar comment earlier in the thread and I stand by it. Explosives are not required to get an object that size to fall straight down.

Allow NASA to quickly revive their dreams for a Mars mission after a change of administration.

Well, it does explain why NASA has continued to fun ATK for it's 5-segment booster effort, but otherwise... I think it's a bad idea.

OK, so you gain 23 s of Isp. But what does it do to density Isp? More to the point: Since you're using a significantly less dense fuel, does the increase in size in fuel tankage, related structure, and new-found fuel tank cryogenic requiremenst make it worth it? Mind you, for 2nd stage and above flight, I'm sure it does but then, I'm not aware of anybody burning kerosene for 2nd stages. I presume you're talking 1st stages. For 1st stages, density Isp seems to be a better metric for performance than simple Isp.

I'm not 100% sure I'm following everything you're saying but.... I'm not sure I follow your numbers. For starters, in one of your links you mention a combined fuel density *INCREASE*. Am I not reading something correctly or how do you propose replacing the majority of the kerosene with H2 but somehow increasing the density of the overall system? Another question: You state that the hard part - handling a high temperature, oxygen rich environment - has been accomplished, but I see no mention of HOW it's accomplished. I mean, if the solution to nasty, expensive turbopumps is a pre-chamber made out of Rhenium, I submit that you're simply exchanging one expensive component for another. I'm not saying that's what you're proposing, mind you. I'm just pointing out that without any details, your claim comes across as smoke and mirrors.

I don't work in the demolitions world. I work in the weapons world. So while controlled demolition of large buildings isn't something I normally study, the consequences of high energy events as it (often) pertains to structures is something I deal with on a routine basis. That said... On the morning of 9/11 I was surprised to see the first tower fall. How/why would it fall with a delayed reaction like that? It didn't take more than 5 minutes of thought to come up with the answer: Thermal soak of structural elements. And in that moment I knew that the second tower was doomed as well. That was an odd feeling... Watching the tower burn *knowing* that there was no hope for anyone still inside. As for the whole, "It fell straight down" line of questioning... Given the ramifications of the square/cube law and common architectural practices, I challenge you to collapse a building that size in any other way! Even if you *tried* to get it to fall over like a felled tree, the moment it started to go to the side it would buckle and just come more or less straight down.

What I think would be the easiest is Enthalpy's first suggestion.... Have a very low power transmitter at the bus stop that just transmits a recorded message ("The next bus stop is XYZ"). Have similar transmitters on every bus stop in town. All transmitters are tuned to the same frequency but each has it's own message. The bus then tunes a radio to the magic frequency.... When the bus approaches the stop, it pics up the transmission and plays it on the bus's PA system. For bonus points, use a high gain directional antenna on the bus with it's primary lobe facing forward. Use a similar antenna on the transmitter that faces in the direction the bus is coming. All easily doable with technology available by the 1950s (although I would suggest using an mp3 rather than tape, but that's not my point). Biggest issue would be people tampering with the transmitters. Thus, put them on the tops of street lights.