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Last night I had a dream. I dreamed of a great bridge that spanned two peaks shaped like the Devil's Tower. The bridge was a single beam-like structure, black in color, but reflective like volcanic glass. It spanned a distance of many miles, and in my dream I thought "There is no substance strong enough to span this distance that would not collapse under its own weight." So I asked myself, "What material would be strong enough to support this span?"

The answer came into my head: "Pre-stressed carbon nanotubes in a diamond matrix." What I am asking all you engineers and scientists on Poal (stop laughing -- there may be a handful of you) is this:

Is a composite composed of pre-stressed nanotubes in a diamond matrix possible? Would it yield the strength that would allow a beam miles long to span the distance between two mountain peaks?

For those who have no idea what I'm talking about, we do much of our construction using pre-stressed concrete. This is concrete that contains steel rods that have been pre-stretched before the concrete is poured around them, then allowed to relax, which puts pressure on the concrete, holding it together. Pre-stressed concrete beams are much stronger than common comcrete beams would be and can support much greater loads.

I was able to find on carbon nanotube reinforcement of composits, but there was nothing in this chapter about a diamond matrix. Is it possible? Would it greatly increase the load-bearing strength of a beam made from it?

Last night I had a dream. I dreamed of a great bridge that spanned two peaks shaped like the Devil's Tower. The bridge was a single beam-like structure, black in color, but reflective like volcanic glass. It spanned a distance of many miles, and in my dream I thought "There is no substance strong enough to span this distance that would not collapse under its own weight." So I asked myself, "What material would be strong enough to support this span?" The answer came into my head: "Pre-stressed carbon nanotubes in a diamond matrix." What I am asking all you engineers and scientists on Poal (stop laughing -- there may be a handful of you) is this: Is a composite composed of pre-stressed nanotubes in a diamond matrix possible? Would it yield the strength that would allow a beam miles long to span the distance between two mountain peaks? For those who have no idea what I'm talking about, we do much of our construction using pre-stressed concrete. This is concrete that contains steel rods that have been pre-stretched before the concrete is poured around them, then allowed to relax, which puts pressure on the concrete, holding it together. Pre-stressed concrete beams are much stronger than common comcrete beams would be and can support much greater loads. I was able to find [this](https://www.intechopen.com/books/diamond-and-carbon-composites-and-nanocomposites/carbon-nanotube-cnt-reinforced-metal-matrix-bulk-composites-manufacturing-and-evaluation) on carbon nanotube reinforcement of composits, but there was nothing in this chapter about a diamond matrix. Is it possible? Would it greatly increase the load-bearing strength of a beam made from it?

(post is archived)

[–] • 7 pts

Such strong material doesn't exist (yet?) otherwise Elon Musk would probably try to create a space elevator.

[–] • 1 pt

No, it doesn't exist. Even the nanotubes don't really exist, because nobody can make them longer than a fraction of an inch, and they would have to be continuous for much longer than that.

[–] • 3 pts (edited )

No, it doesn't exist

That's exactly what I said, but I'm pretty sure that with advanced ML/AI, we'll eventually be able to create new materials. The main issue here is the production cost. If it's not worth it, they will not spend money on it, or we would have batteries with capacities over months.

[–] • 5 pts

The short answer is no. Carbon nanotubes are not exceedingly strong under compression, so prestressing them doesn't yield great strength.

Concrete is absolutely terrible under tension and sheer. A quality concrete cylinder on which the weight of a car can be balanced can ripped apart by an average strength man. You prestress concrete to ensure the concrete stays under compression under all expected structure loads. Also

steel rods that have been pre-stretched before the concrete is poured around them

is not the way prestressing works. The pre is before the structure load is placed on the concrete. Not before it is poured. Usually, a steel rod with threaded ends is placed when there concrete is to be poured just like rebar. The concrete is allowed to sufficiently dry. Then fasteners are tightened on the end of the concrete to achieve proper compression of the concrete structure.

[–] • 0 pt

Actually you can pre-tension as well as post-tension concrete. Post-tensioning is done with cables in a sheath, tensioned after the concrete is set. Concrete can also be pre-tensioned with cables tightened before the concrete is placed. Post tensioning is handy since the pieces can be cast then transported with the tension load only added once the piece is in place.

[–] • 0 pt

Looks like you are correct. I've never seen stuff done this way, but I guess its usually used for prefabbed parts.

[–] [deleted] • 5 pts

There's a saying among engineers:

"Anyone can build a bridge, it takes an engineer to build a bridge that barely supports itself".

So, to answer your question, yes, you can do it. Just make a big pile of nanotubes and diamonds between the two towers. But if you want to use the minimal amount of material... Well, that's an interesting question... my answer?

"Fuck if I know. Make some carbon nanotube reinforced diamond beams and maybe we can do some material science tests on it".

[–] [deleted] • 2 pts

Diamond is already highly ordered unlike concrete. It's crystaline and the carbon atoms will already be aligned into sheer planes and bonded at the atomic level like a continuous carbon sheet because of that. Concrete does not have such a structure.

[–] • 2 pts

If something like this existed, the jew would already be profiting from it.

[–] • 7 pts

They would build a bridge straight from africa to your local town.

[–] • 0 pt

What do you think this question is for? Damn jews tryin to get whites to tell em how to do that.

[–] • 2 pts

Quit reading Stephen King before bed.

[–] • 0 pt

The Gibraltar Bridge has been long dreamed of.

[–] • 0 pt

Interesting thought. Try picturing a theoretical nanotube stretched between the two points. As you pull it tighter the load on the anchorage climbs from just over half the weight of the tube toward infinity as you approach a condition with no sag. At what point would the tube be stressed beyond its tensile strength? Beats me--not my specialty but such materials will be around after I'm not. The future can be cool if it doesn't end up being a boot stomping on a face forever.

[–] [deleted] • 0 pt

such a material exists- i recall reading about a diamond like material created in the same method as diamond is made from graphite, but from carbon nanotubes. the claim was that it was stronger than diamond.

sorry i don't have a reference for you

[–] • 0 pt

See your psychoanalyst.

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