p1t1o

Any solution that deals with objects on a one-for-one basis is doomed to be ridiculously expensive. Though I do like the Moby-Dick level of engineering here. There arnt that many discussions where "Shoot a spear at it" is a legitimate response. Has anyone considered adhesive-based capture systems? Using something like this kind of riot-suppression foam? You wouldnt "hose down" the target, you'd just kind of expand a bubble of sticky foam and bump into the target. And if it set hard, it could still retain objects that didnt adhere too well. Plus no risk of shrapnel, and less risk of just shooting the target off onto a random trajectory.

I dont even think we have a fixed scheme here in the UK. I attended 2 different schools with 2 different scheme and they never seem to be the same ones that anyone else had. When I was 12 I was in "year 8" and the next year I was in another school where I was in "4th form" (so "year 8" would have been equivalent to "3rd form") So I just go by how old I was at the time. "What grade were you in?" "I was 12" PS: in my 2nd school, the year after 4th form was called "remove", THEN you went into 5th form. Like there was a year just called "remove". Yeah I know.

lol yes I remember stumbling across various websites and little me thinking "OMG I just found some ultra-black classified stuff....better not look at it too long, they might find out...woah, people need to KNOW about this!! The Soviets contacted an alien race decades ago? American secret military bases on the moon? Victorian-era particle beams? Hitler cast magic spells during WW2? Wowowow!! Hardly anyone must know about this...it feels good to get this wool offa my eyes..."

mmmmmyeaaahh sort of, its still a very different regime.

Sure, you can use them to compliment each other, but it sure sounds like combining them into a single thing is not optimal.

The biochemistry of water-based life is finely tailored to the solubility profiles of things in water, so "porting" over genomes would be problematic. Proteins will not fold the same way in a different solvent and god knows what other effects there would be for gene expression, I think the whole thing would have to be re-written. Having said that, there isnt any fundamental reason why life couldnt exist in other chemistry systems. Ammonia is a good example, it shares many of the properties of water that makes water so conducive to life. Silicon is also considered a viable alternative to carbon, in that its electronic structure and bonding is quite similar, a similar range of compounds can be constructed from it at similar energies.

Whilst Im sure its possible, I can think of one issue. Generally you want solar panels to face the sun - expose as much area as possible to the light. With radiators, you want them edge-on to the sun, so that they can shed as much heat as possible.

That doesnt stop the initial claim (not made by you, I know) from being pure hokum.

Because thats liquid fueled rocketry if Im not mistaken?

Yes, definitely. The mass must be sufficient to produce conditions in the core to start fusion. Nope. Observe - Jupiter is not a star. *** https://www.google.de/search?q=minimum+star+mass&oq=mini&aqs=chrome.1.69i57j69i59l3j0l2.5775j0j7&sourceid=chrome&es_sm=122&ie=UTF-8

Occam says this is a good explanation. You want to run a cold-gas rocket straight from non-liquid gas store? Tank must be at a much higher pressure than that at the nozzle throat. Tank must also be very large to prevent significant pressure drop as gas is used. And this rocket want to be hypersonic? Tankage is going to be heavy. I havnt done the maths, but if a hypersonic aircraft is possible with cold gas, without using magic (such as storing at a billiion atmospheres) then Im a monkeys uncle.

Perhaps not but it sure sounds like pure snake oil/pseudoscience. I do not think that there were any military pilots discussing details of black projects that flaunt known physics on Tucker Carlson, whatever one of those is. A hypersonic drive that cant be picked up on IR? So I guess it magically stops friction and compression-heating too? And thats on top of the fact that "heatless" is a HUGE claim for so many reasons. And thats on TOP of the mere fact that "hypersonic" is still a very loud shout on its own. The first piloted hypersonic aircraft is ALSO going to perform "maneuvers that would be complicated with modern technology" AND have the physically implausible property of being "heatless"? I dont think so, someone is telling porkies. It may even be thermodynamically forbidden to move energy from one place (fuel) to another place (kinetic energy of the craft) without waste heat being produced. Isp of compressed gas is terrible, it is not a viable propulsion system, doesnt matter what you do. Rockets work great because hot gas has tons of energy in it, the gas wants to expand fast. Cold gas? Yeah pressure forces it out pretty fast, but temperature in the tank drops rapidly (to the point where it can start to liquefy the gas), which reduces pressure, reducing flow. Not to mention lack of energy in the exhaust. Its a very mediocre rocket. High-pressure tanks are also heavy. Metallic hydrogen can have an Isp of up to 1700s, which is pretty impressive for a chemical rocket, but still mediocre if you're talking about an aircraft (rather than a spacecraft), present-day airbreathing engines have Isp's in the 3000-6000+ range. Metallic hydrogen is also not plausible to store at this point, not enough is known about its behaviour at low pressure. Storing it as gas-giant-core pressures is...not plausible. So how would we go about hypersonic propulsion in the first place. If its air-breathing, the concepts are well known. At hypersonic (Mach > 5ish) speeds, the temperatures and reaction speeds start getting in the way of the thermodynamic performance of your engine so you have to do things like cool the incoming air (Skylon/SABRE), introduce supersonic combustion (scramjet, X-43) or dramatically change the way the fuel reacts (detonation engines - faster reaction, more efficient energy release). All of those are plausible - but not yet serviceable, and they all produce a LOT of heat. I mentioned friction and compression heating of the fuselage before, this is difficult to get around, even at high altitude, the skin of your aircraft will get very hot. In most designs, fuel is piped through the skin to cool it, this heat is then "dumped" overboard when the fuel is burned in the engine. So even if your engine produces (somehow) zero heat, you still have to figure out how to cool your aircraft. Resevoirs of liquid helium might work for a while, but I doubt its going to be of much operational use, if stealth is what you are going for. Wouldnt last long enough, or the extra weight reduces effective payload drastically. So how do we fly at hypersonic speed, with a low IR signiture? 1. Fly in vacuum where there is no air resistance. 2. Do all your thrusting out of sight of observers and coast the rest of the way, avoiding heat signiture from thrust. We just described satellites.

Er ok, ummmm.... Matt Lowne should eat a bowl of nails. Who is Matt Lowne?

How tall are the biggest slopes on the Moon? Because Im up for some lunar skiing. The powdery regolith sounds like it would make for some good skiing, as long as your skis were durable enough. You'd take a long time to build up speed, but due to the lack of air resistance, top speeds would be much increased! *** Just did a little googling and the tallest "mountains" are on the order of 5km base-to-peak! Thats plenty of skiing! (and plenty of distance to build up some speed) The idea of falling onto rocks at 100mph in a spacesuit does make my stomach wobble a little.

Asked and answered, noice

If Jupiter is made largely of fluid - there is a possibility of a solid core, but this is uncertain - at least the upper several thousand kilometres are fluid, and we can only observe a fraction of this. Not only that but of the layers we can see, they can rotate in either direction, at varying speeds. Taking all of that, how can we say that Jupiter "rotates". It has a "day" length of around 10 hours. Which part is rotating once every 10 hours? This band? That band? Do we have some kind of handle on what the deeper masses are doing? In other words, how do you measure the rotation of a swirling ball of fluid?

Hi Steve, Do you have a book for sale by any chance?

Many a young, aspiring scientist has had thoughts like this. "Feelings" that they are certain ought to pan out in the real world, something that we all learn eventually is that science and the universe care nothing for our feelings. Dial back the skepticism a little bit - skepticism is healthy, but not to the point where you question the entire framework in which you are trying to operate. Anyway, for what its worth, Im a professional scientist. In my career I have worked in many fields from academic research to commercial research to industrial labwork to industrial deskjob - from electron microscopy, to bio-mineralisation, to wound-healing and now chemical safety, and here is my schpiel: I mean honestly, as a scientist, why do we get all the stick? Nobody ever argues that dentistry is "ALL WRONG and heres an idea for everlasting teeth", nobody ever argues with their plumber that toilets dont really work like that. Science is a very old, very wise, experienced lady. One should not presume to challenge her with a mere few years "contemplation" under your belt. And with that, this thread was done for me. This is a conversation that I have had too many times. Dint-ding-ding! THIS ^^

Ah sorry, my mind must have skipped a beat there Yeah I dont think anyone is in doubt that the whole thing was hokum. I mean... ...thats one hack of a red flag! Right?

Now we start getting into the definition of "what is clean?" which as it happens, is a field of science my father is involved in. For most of recent history, "sterile" has been the epitome of "clean", but science (or probably more accurately and frustratingly, "public opinion") is starting to catch on the the fact that we live in symbiosis with a huge crowd of microbes and a sterile environment and sterile body surface is far from ideal, even to the point where it can make you unwell. Indeed, different area of the body have their own unique environments and are not directly comparable merely based on microbe count, however hands are SO dirty (because these are our instruments for interacting with our environment, their flora are affected more by outside bug) that I still think it is a valid comparison, to say that hands are one of the "dirtiest" parts of your body, taken not on pure microbe count but the sheer unknown nature of the colonies - because it is affected by whatever you touch (and whatever has touched what you are touching etc.) not just by the natural body flora. And because we dont touch our genitals much (lol lol yeah I know, I mean in the grand scheme of things) they tend to be fairly clean, in terms of bugs from outside. On the "definition of cleanliness" front - the cutting edge may soon include cleaning products which actually contain colonies of bacteria, "infecting" surfaces with "beneficial" clades of bug.

Apparently, the patent application did not describe the actual dean drive. Only a couple of people actually claim to have seen it aside from Dean himself, and they claim what was described in the patent was not what they saw.

Isn't it radioactive? Could be a factor? Ionisation energy is also a thing, perhaps it's less favorable. I'm out at the mo, can't do my usual research

To avoid derailing the thread, I'll bite my tongue, but suffice to say I remain unconvinced (and if the m4 motorway is anything to go by, some people shouldn't have access to cars either )

@YNM Very "Logan's Run" If you look closely, the "driver" is a mannequin in a weird "Im dead" pose. In fact, there is something odd about this whole thing...the scale seems odd.. *** AH-HA! https://en.wikipedia.org/wiki/Supertrain Wow, what a weird program! Thank you for this!

Its be weird to make the rocket fit the train, and not the other way around, too. "We cant go to space, our....trains are too small?"