Architectural Lead Sheet and Archimedes Buoyancy

Just for the record, my dear Physics Tutor, Thr Rev. Dr Burley, gave this example as a first example of Archimedes Buoyancy Principle and an introduction to use of a Slide Rule. Air was described as being 1.29 Kg per cubic Meter at S.T.P. and the relative density of Helium to Air, 1: 0.139 ......We then went on to discuss how Helium might have influenced the development of Zepplins. Helium Gas can, I seem to recall being told, represent a significant small percentage of Natural Gas. The importance of doing the mathematics before jumping to conclusions, was well hammered home by this astonishing inspirational example.

I can relate how a certain Drummer, John Bonham picked up on the idea....and was it Jimmy Page who seconded the 'Name Change'? of a small virtually unknown Band that toured the College Campus's of those heady days.

Check out http://www.rense.com/general30/nasa.htm "NASA Images find 1,750,000 Year Old Man Made Bridge" For details of how proto-homo-sapiens supposedly floated huge blocks of volcanic pumice to form a bridge from India to Sri Lanka 1.75 million years ago according to The Epic Hindu Poem 'The Ramayana' by the great sage Valmiki. Now Nasa are claimed to have photographed it from space. The Hindustan Times are hot on the storey. Lord Hanuman's Bridge. here is a quote from The Ramayana Epic. "Those monkeys thereafter dived, swam and shouted at the sight of that unimaginable marvel that was almost inconceivable and caused one to tremble! And all beings beheld that causeway thrown over the ocean and by hundreds and thousands of kotis (millions), those monkeys, full of valor, having built that bridge over the immense repository of waters, reached the opposite shore." I certainly remember the 'C-ment' boats. a good friend built one, He even used chopped glass fibre + cement + coarse & fine expanded polystyrene, to fill the bottom of the hull and also make thick partition walls. so as to ensure the craft stayed afloat, in the event of a hole. This light weight aggregate also provided good insulation and imparted considerable 'stiffness' to the structure.(at the expense of 'cabin space') Happy Days.

I'm kind of late noticing this interesting convo . Theres a great 'synchronicity' going on (or perhaps convergent evolution ) going on . balloons - led zep - stairway to heaven - planetary hula goop- ...

There are a huge number of threads on cr4 where people do not notice that others are addressing similar issues elsewhere . Transference of knowledge from one area to the other has to be one of the greatest potentials of the internet. I was once asked if I was a 'specialist' or 'generalist' . That really left me scrambling for a 'right' answer ! Kens concrete boats would be of interest to other threads (as well) I'm sure.

Transference of knowledge from one area to the other has to be one of the greatest potentials of the internet.

The info available is simply staggering. The whole MIT curriculum, available to anyone anywhere??!! Google often comes up with the "wrong" stuff (sometimes quite humorously so) but it also often comes up with just what you want to know. I suspect that there will be a new approach to searching that will make it more likely to get want you want -- but I don't have a clue as to what that approach might be.

We need 'Computer' from Star Trek Next Generation .

More seriously , fighting through the fact that everybody can post an opinion on everything is the challenge . How can you evaluate a sources validity before reading . A nasty paradox , which could mean ignorance by suffocation . Pity those growing up today who lack skills to use books and don't get taught the principles of cross-referencing. The net is the ultimate case of 'let the buyer beware' and don't believe all you read. It's hard to see how filtering and search technique can overcome this (at present , and I think for quite some time ) . Like other areas , the tool outstrips the knowledge to utilize it best - perhaps this is an inescapable fact.

Hi Ken, I may be able to answer that one for you. ask Ramona. She takes up about half a meg of hard drive. Dr. Ray Kurzweil's website had the download details. She is very pleasant to talk to, and is fairly good at esoteric conversation. I expect soon, her conversational repertoire will be indistinguishable from any Professor on the planet.

Hi Kris, Sorry to take so long responding, Yes indeed, there is an amazing synchrony going on here at CR4 and generally on the internet....WOW!....what more can I say? I have to admit, that I find great fellowship with the contributers to CR4. Remember that as an 'applied' mathematician, rather than a pure theoretical mathematician, my dead soul is being prayed for. In fact I am under sentence of death for my apostasy. Any bone fide mathematician can kidnap me around about November 5th would be a convenient date, immobilise me with a shot of whatever, then tie me to the stake and light the bonfire. There would be little of me left in the ashes. I would simply go on the missing persons list. I am sure a real mathematician would regard my skills as akin to a well trained parrot, impressive to some, but not very enlightening.

I sense that Science and Technology are catching up, my dead soul is being awakened by amazing possibilities. All I need now is a bolt through my neck, secured with a left-handed spanner.

You seem to be very tolerant of my shameless name-dropping, but it is for the historical record, rather than for self aggrandisement. You spotted the 'Stairway to Heaven' bit...and now the floor is going to get wet beneath my feet. 40 years is a long time to wait. it has been an emotional roller-coaster of a ride. so many have passed on. This project is ancient. we can start all over anew. Saturn already has the material in place. Don't forget Jimmie Hendrix, He played a good rendition of "The Star Spangled Banner"......I want that track played on some decent kit again. for a real inspirational purpose.

Oh Cointreau (as Del boy would say ) viz the names . They add real fun to the threads . Part of cr4's brilliance is the opportunity to mix fun and serious stuff . As you say , the fellowship is great .

I wouldn't worry about the pure mathematicians - the match will burn before they agree on where to start the fire for best result. My clock ticks like wise - but I think it into going slower . Having a Dad who was often seen in a Pink Floyd t-shirt may be the cause ( it was looking dated even in the 70s , still my mates reckoned he was cool)

Phew! thats a relief Kris,

You are up late, burning the midnight oil? I'm on sort-of-duty here in Bonnie Colne Lancashire, got one call just before two, which is nice. Semi-retired really means flexi-hours, The quiet of the night is a great time to muse, plan ahead sort of thingy. The James Bond remake of Thunderball, could be a corker of a fillum as they call them in Eire. I posted the first photo I took with the Sony DSC-R1, that I splashed out on Christmas 2005. It was of a super chum, Mr. Chris Taylor Esq. One of our top 'Glow-Boys' now here is a coincidence, Chris Taylor's Partner in Nuclear Crime (They are called 'glow boys', coz they enter reactors to clean/apply surfaces etc. Red Scar Industrial Coatings Ltd.) was Balfour Beatty's....Plug:- http://www.balfourbeatty.com/ Top Blasting Banana. Pete Vernon, ....not a bloke to rub up the wrong way!...but a Scholar and a Gentleman all the same. For obvious security reasons, they have to carry sophisticated IDs, each one is for life and numbered. It was the luck of the draw, but Pete's No. is 007.....Cue music.....Chris was adopted as a baby, hence the name Taylor, he spent a small fortune trying to trace his mum & dad. Then one day circa 1994, a detective agency that had milked him for over fifty grand over the years. they had searched high and low, and earned the brass! struck lucky, They had located his Mum outside Londonderry Northern Ireland. I was invited to the reunion. which was cool. Chris introduced me, "Alastair I would like you to meet my mother Mary"...... Mary Bond.......Now I leave you to guess the name of Mary's Father. and No Prizes......Cue music.

Another cheery start to the day . I was up early - I'm usually a lark more than an Owl . I find it much more productive (no distractions etc , though when Luke (son) is up and running it's my cue to shout "school bus is here , I'm off now " which sounds kind of weird ! ), and a really early morning stroll is great for the mind . Of course it helps that I can give Mrs T a run for her money on sleep needs , the downside is that when I'm on holiday I can sleep for England .

"Luke" is the Patron Saint of The Artist's Rifles. Because mainly one of my best buddies at Well Coll, was son of the Top Catering Corps "Only the Chaplain General is allowed to wear more scrambled egg over his best bib-n-tucker-n-peaked cap" ...Brass....No names allowed. I volunteered for both.

Now here is a simple sum. one million square section rods 1mm x 1mm x 1000mm are stacked in a square pile. OK to be pedantic a cubic pile. if joined end to end, how long would the rod be? if made from regular steel, how much would it weigh? and how many Transport planes would be needed to encircle the equator (40,000 klicks)

Just flying a kite here, they don't have to be square rods, but mag-lev inserts have to be a shape that won't twist to a mag-stick! (1/2 Kilos x [Meters/sec]^2) = Joules

School bus not far off ! I'll be back later

While on the topic of music…

I enjoy Kate Campbell's song "Bud's Cement Boat". ("Cement" is pronounced with the accent on the first syllable.) It describes a guy who followed his dream to build a concrete sailboat, despite the criticisms of his neighbors. There was a time when such boats were almost common among home-builders, although now almost no one builds them (for many good reasons). Like Led balloons, concrete boats float just fine.

I've intended to build (when I have nothing better to do) a carbon fiber sphere of a size that could be evacuated and then float in air. (I haven't done the math, but I think that a carefully constructed sphere could resist implosion at a differential pressure that would allow the thing to float.)

Given Led's very low stiffness and high density, I wonder whether a 109 meter balloon could actually be constructed. Once constructed, I'd guess that it would have to be pressurized to significantly above atmospheric to retain even a semblance of its spherical shape.

I too used a sly drool in high school and college. Still have a circular one intended for use in flight calculations, but I don't think I have a straight one anymore. It might be a nice thing to have, particularly since by brain rarely works to any better than SRA these days.

After posting, I looked for people who have already done this sort of thing, and came across this :

http://www.faculty.fairfield.edu/jmac/sj/scientists/lana.htm

Lana's balloons were pretty impressive for the 1600's. They were far too small, and copper would not have anything close to the required strength-to-weight ratio, but the concept is there. Given his insight in other respects, it is interesting that he didn't see the essential flaw in how the craft would be propelled and steered.

Bless you Ken, That link was excellent, 1670! and his objection to the project was that aircraft might be used to bomb cities and fortresses with impunity. A man of perception, methinks.

I think the figure of 25 feet diameter for four balloons to suspend a boat and passenger is a little optimistic. 1195 kilos displaced air, by my calculations for the four balloons. and 730 square meters of surface area. That is cutting it a bit fine! even honeycomb carbon nanotube paper would never work. Jesuit Science was certainly a boost to the Renaissance in Europe, as can be seen with the numerous hyperlinks on the page you cited. The concept was inspirational to Montgolfier. The young Napoleon was said to have been so impressed watching the first Montgolfier Hot Air Launch, that it is believed Napoleon commissioned a feasability study for a hot air balloon invasion of Great Britain. Reconnoitre from an aerial vantage point was regarded as a more practical application of the technology.

Now here is a thought Ken, go out and buy a few hundred good quality party balloons. Nice big ones. Blow them all up to the same size, with say, a twelve foot length of strong fishing line tied to each balloon. Using a suitable geodesic spherical frame as a jig, fit all the balloons together into a sphere (on the inside of the 'jig') useing double sided sticky tape. Have all the tether strings join at the sphere's center....Pull tight....and dismantle the 'geodesic jig'. You should now have a sphere of balloons.

Now start pumping out the air. Clearly not all of it, just enough to provide buoyancy. The pressure in the balloons, coulpled with the spherically radiating spokes (much like a bicycle wheel) should prevent the total sphere from collapse.

Let's DO IT! and if it does not work, too bad. Lana's other reason, we read, for not proceeding with his vacuum balloon project was his Jesuit Priest vow of poverty. It would he estimated have cost 200 Ducats (25 troy ounces of Gold). Party balloons would not be too costly, and the geodesic jig could be made from tightly rolled newspaper struts.

Oh yes! Wide cling film might come in handy,to ensure no leaks.

Hmmm. Interesting. I'm assuming there is a membrane around the entire structure from which we'd be pumping the air. Eventually, the balloons would expand to fill the entire space contained (even though their internal pressure would, by then, be below atmospheric), which would be a pretty neat effect. The outside would be dimpled like a golf ball, and the inside balloons would appear to have been blown up really hard to fill all the space. I'll have to get a few balloons and weigh them.

Another possibility: We come up with a system of nicely rounded joints to build a geodesic sphere or similar shape -- maybe a dodecahedron. The joint system would enable the structure to be easily snapped together out of small carbon fiber tubes. Then we buy a weather balloon, and cement some rubber gloves into its surface. Stuff the materials into the balloon. Inflate the balloon. Build the structure inside it, ship-in-a-bottle style. Let the air out of the balloon, then partially evacuate it. The faces would all be spheroid indentations, and perhaps (before they all meet in the middle) we'd have a floating balloon. The exercise would be a good one for a class on structures to model: the stiffer and thinner the rubber, the higher the probability of success. Would be interesting to find the optimum level of evacuation: too little, no float... too much no float.

But then again, balloons can burst with from lung pressure (maybe 1/10 atmospheric differential) so if 1 CM will support 1.29 kg, then our structure would need to have a mass of about 120 grams per CM. Just the search for the right material would be fun: we'd build lots of balloon like things, and inflate them until the go bang!

Hmmm, make a thin polyethylene bag out of a couple of cheap painter's tarps… I think I may still have some pultruded carbon fiber tubes… Two cube frames, each twisted 45 degrees in all three planes from the other, some thread…

Ken, you are a hero. Thanks for taking an interest. Just woken up and seen your posting. Then I did a search for coated 'Ripstop' nylon fabric. Seems that high reflective fabric 64 inch weft. 1.3 Oz per sq.yard, is available. Now silicon rubber is a cinch to bond together. even bathroom sealant works. I like the idea of twelve pentagonal 'air-bed-thingy-dimply-curved-panels'. RTV silicon can be readilly diluted with 'Genclean' dry cleaning fluid (or has that been replaced now coz of ozone worries?) Before I nodded off, I calculated that a minimum of 60 balloons would be needed. an icosahedron has 20 sides. so three balloons per side. or six, ten, etc.

Over here at the works we have some reasonably fancy kit. squash an 'Abrams' battle tank into a pancake with one of the presses.(perhaps not?) but more importantly a barrell roller for rolling sheet metal into a spherical profile. We also do PTFE coating. If I catch the boss on a good day, who knows? ....pentagonal airbed mass production? with a well designed manufacturing setup. From little acorns....as they say.

Postscript:- The ubiquitous truncated dodecahedron, might find a market with soccer fans? and 'say no more' a metalised airborn sphere can reflect a lot of wavelengths, over a broad terrain.

If you are looking for cheap carbon fibre tube, about once a month a skip full is sent for landfill. When they make 'Carp Poles' from slightly tapered carbon fibre reinfoced tube, they slip a thin tube through a thicker one....result, simply loads of short length off-cuts ranging from a foot to two and a half feet. My brother was recently asked to make the wedding speech for the CEO of a firm that specialises in this. Then there was a firework show on the Thames that outdid the City of London, having their show a few minutes earlier down river!

News, ...I have found my old dog-eared copy of 'Domebook 2' with all the appropriate 'chord' lengths for the struts. Now I think it's going to have to be those 'Jumbo' straws kids use for drinking milk shake for the struts. Twelve five-hubs needed, and I can't decide yet how many six-hubs. Those will be the tricky bits....if I can locate my hair drier, maybe we can stretch those jumbo straws just enough to make a nice tight fit at the hubs?.....That lovely smell of modelling glue, takes me back to my days in short trousers and constant grazes on my knees.(need to test a variety of glues) Each hub will need to have a hollow tube faceing inward to attach a suitable balloon. If the hubs incorporate a simple one-way air valve, that might be cool? ...will definitely have to test hub-to-hub tensile strength! plenty of research there.

'Pneumo-Tensegrity' sounds about right, for what to name it. Then after the prototype works (or fails), perhaps do a fast motion video for 'YouTube' kids to watch and maybe emulate?