Transparent Concrete

rakerman writes: "The Economist reports in How to see through walls that development is underway on translucent concrete, with hopes of eventually developing transparent concrete. Can transparent aluminium be far behind?"

Comments

But what about the birds?

[Eharley]

Won't translucent structures lead to an increase rate of smack death amongst bird populations?

Re:But what about the birds?

[Drakin]

Think of this way... advanced natural selection.

The only question is, will the birds die off before an effective way for them to naigate arises...

Re:But what about the birds?

[IainHere]

I used to walk over a bridge with large glass windows, where there was a silhouette of a bird of prey. On the back was a caption that read "this cut-out is here to scare off small birds, which used to fly into the bridge and *subsequently* kill themselves". I often wondered why, having survived hitting the bridge, they would want to commit suicide. So perhaps they'll do the same on transparent concrete?

Re:But what about the birds?

[HarryTuttle]

I often wondered why, having survived hitting the bridge, they would want to commit suicide.

Embarrassment

Hmm...

[Drakin]

Well, it's nice to see innovation within the construction sector isn't dead. Even for something that seems so off the wall as transparent (or currently, translucent) concreat can give birth to innovative new designs and possibilities from architechs.

I mean, I can just see a wall done with a bubble effect (with slighly differnt opacities in the aggitates and clear binding coumpound).

Only thing is, once transparent concreate is perfected... how are the mobsers going to get rid of bodies if they can't throw them in the foundation of a new building anymore...

Re:Hmm...

[spectral]

with transparent concrete shoes, of course.. The divers will keep trying to lift the body out of the water and not be able to figure out what's holding it down, since they can't see the concrete! :)

Re:Hmm...

[Drakin]

Well, with how often the police drege the river and lake bottoms, there's just too much chances of being caught dumping cement shoed people down there...

Re:Hmm...

[dillon_rinker]

how are the mobsers going to get rid of bodies if they can't throw them in the foundation of a new building anymore...

Hog farms. Hogs eat everything. Only fillings pass through intact...

Re:Hmm...

[bpowell423]

okay, you're right, but that's disgusting.

Re:Hmm...

[ParrotDroppings]

...once transparent concreate is perfected...

I'd vote for privacy-curtains around the Xerox in the office!

Transparent Aluminum is for *Rebar*

[billstewart]

The article mentions the problem that it really needs a transparent reinforcing material to work well. So obviously transparent aluminum is what you want for rebar....

Re:Transparent Aluminum is for *Rebar*

[Sun]

It has been my understanding that all metals must be the color they are, because of the way electrons swim around in the metal meta-crystal, and the way they interact with hitting photons.

If this understanding of mine is correct, transparent aluminium (or any other metal reinforcement) is not likely to happen, but some sort of plastic may do the trick.

Re:Transparent Aluminum is for *Rebar*

[GreyPoopon]

It has been my understanding that all metals must be the color they are, because of the way electrons swim around in the metal meta-crystal, and the way they interact with hitting photons.

I believe your understanding is correct. However, it may be possible to develop a "metal" (maybe alloy or ceramic) with very similar chemical structure to aluminum that possessed all of the same qualities minus color. Obviously, it wouldn't really be aluminum, but it might be real real close. Who knows.

Re:I may as well say it....

[rehannan]

From the article:
He has visions of cities that glow from within, and buildings whose windows need not be flat, rectangular panes, but can be arbitrary regions of transparency within flowing, curving walls.

That sure sounds remarkably like Apple's philosophy...

How to see through walls

[Hal-9001]

They're called windows, and they're usually made of a neat transparent material called glass... ;-)

Seriously, though, any slurry-based material like concrete is most likely to be opaque because microscopic structures tend to scatter light. You only need to pour a glass of milk to see this in action.

Re:How to see through walls

[Hal-9001]

Some people (*cough*moderator*cough*) have no sense of humor and don't know anything about the subject they're moderating... :-p

Re:How to see through walls

[Digitalia]

And each window needs to be constructed elsewhere, shipped, and placed in a hole that is sunk in a wall after the wall is in place. In conrete construction, this entails a good deal of work to do successfully and the benefits to doing so are limited. In fact, in doing so, the insulative value of concrete is often lessened. By having a "window" of transparent concrete, our structure sacrifices less of its insulation and the work required to place them is lessened. Furthermore, transparent concrete would allow for even more artistic placement of windows in modern architecture, since the window could be load-bearing.

Even if the engineers only managed to make the concrete translucent, it would still be of some advantage.

Re:How to see through walls

[Pathetic Coward]

Windows is a trademark of Microsoft Corporation.

Please use the term "transparent exterior access devices".

Re:How to see through walls

[Stary]

Furthermore, transparent concrete would allow for even more artistic placement of windows in modern architecture, since the window could be load-bearing.

Well, I dunno about you, but at least I like to be able to open a window once in a while. The transparency is not the only benefit of windows, so before they solve that issue I can't really see this as being used to replace windows in homes.

Re:How to see through walls

[GreyPoopon]

Well, I dunno about you, but at least I like to be able to open a window once in a while.

Agreed, but think of the lighting issues. Put some normal windows in so they can be opened, but if you construct large portions of the wall out of translucent (or transparent) concrete, you get some awesome natural light in the room. Personally, I think the translucent may be better if it can provide some of the light with privacy. Of course, I can only imagine the cost of manufacturing a custom blind of more than 50 feet in length....

Re:How to see through walls

[Mydron]

You may have a point about transportation and convenience, but your argument about insulation is nonsense. The insulative value of concrete is almost nil. (regular concrete, who knows about transparent concrete) In fact, 8 inches of solid concrete is equivalent to 1/4 inch plywood in terms of insulation.

About load bearing windows: unless its a firewall no one is going to construct an entire solid wall out of concrete, its too expensive! You may have noticed, during construction, that modern "sky-scraper style" building construction (which makes extensive use of concrete) requires no outside walls at all.

Re:How to see through walls

[susano_otter]

I can't really see this as being used to replace windows in homes.

Especially as concrete is not much used for building homes. No, this will be used for the ubiquitous downtown office buildings, if at all.

Transparent aluminum

[digitalunity]

I seriously doubt we will ever see transparent aluminum. In order for it to succceed, the atoms would have to be aligned in a crystaline matrix. Such a matrix would likely create a hard, yet weak substance.

It would have much strength, yet it would fracture easily. Its called "Modulus of elasticity"; something certain steels(H11 namely) holds in spades. I doubt even if it could be produced, people would find it of much use.

Re:Transparent aluminum

[GoRK]

Well, we already know the best use of it is to put windows in our starships. (heh) But even the starship windows are actually an aluminum alloy.

[For those of you missing the whole joke -- the windows on the spaceships in Star Trek are supposed to be "transparent aluminum"]

Pure transparent aluminum might be weak indeed, but perhaps it can be used in an alloy to create a transparent sheet that is as strong and durable as oridnary sheet aluminum. I find it hard that you mention steel (in particular certain varieties) yet you fail to address the usefulness of a transparent aluminum component in such an alloy.

Heck, even laminating something ordinary (ie lucite, glass) with such a material would have immediate benefits. Think diamond-tipped bits, saws, etc.

~GoRK

Re:Transparent aluminum

[Hal-9001]

Such a material already exists--in fact it predates human civilization. It's called Al2O3, or alumina, and more commonly known as sapphire (or it's chromium-doped cousin, ruby). It has a hardness of 9 out of 10 on the Mohs scale (the only harder material I know of is diamond) and is transparent in the absence of impurities. However, it is not an alloy--it's a crystalline oxide.

Metallic aluminum cannot be transparent except in thin films; this will be explained in a reply to the top-level post in this thread.

Re:Transparent aluminum

[Danielle Gatton]

Hard but brittle is what I think he meant. You can use a diamond to scratch or cut anything (it is hard), but you can also easily smash one with a hammer (it is brittle).

Re:Transparent aluminum

[Hal-9001]

The reason you will never see transparent aluminum is not because of a lack of crystalline structure--in fact, I think metals generally are crystalline or at least have a crystalline microstructure. The reason that aluminum, and basically all metals, are opaque is the same reason that metals tend to be shiny. Because there are a lot of free electrons in metals (which is why they conduct electricity well), the electric field of light expends energy driving these free electrons (therefore metals are opaque), which in turn reradiate light back in the direction of the incident light (therefore metals are shiny). The amount of light that gets through goes as e^-ax where a is a constant and x is the thickness of the metal, so in a very thin metal film (e.g. mirrored sunglasses) you can still get some light through, but for any measurable thickness of metal (e.g. aluminum foil and anything thicker), the amount of transmitted light is negligible.

I know this is a very hand-wavy explanation, but it's hard to explain without a pretty advanced background in electromagnetics. If you want an explanation of this from a rigorous electromagnetic point of view you can try wading through Chapter 14 of Principles of Optics by Max Born and Emil Wolf, but its mostly math with very little physical intuition or explanation.

Re:Transparent aluminum

[cowbutt]

I doubt even if it could be produced, people would find it of much use.

I dunno. I find it invaluable for transporting live whales in my time-travelling starship, complete with enough water to for them to move around in.

I could use steel or something, but, darn, I like to press my nose up to their enclosure during the journey.

--

Re:Transparent aluminum

[Nicolas MONNET]

I seriously doubt we will ever see transparent aluminum. In order for it to succceed, the atoms would have to be aligned in a crystaline matrix. Such a matrix would likely create a hard, yet weak substance.

This post is rather amusing when you know that:

1. most metals as we know them have a crystalline form, except maybe mercury as it's liquid at usual temperatures, and

2. glass is NOT crystalline, and yet is the first thing we think of when we think of a transparent material.

3. plastics, which are the second thing we think of, are not crystalline either, they're polymers, id est long chains of molecules.

Re:Transparent aluminum

[digitalunity]

Yes, metals have a crystalline microstructure. However, not all metals are aligned into a full crystalline matrix. The best example of this is cast versus forged aluminum. Under high magnification, you can observe the alignment of a forged sample and the relative disorderliness of a cast aluminum sample.

Also, one very good example of opaque or transparent metal is any professionally chromed auto part. Any real chroming process follows like this:

Polish to a very low RA(Roughness Average). The lower, the better. Electroplate a few thousandths of nickel. This is what makes 'chrome' shiny. The chrome itself is merely a hard shell. The nickel is what is really doing the reflection. After the chrome is electroplated, repolish. Done. Mirror finish.

If any of these examples are difficult to understand, I apologize. My main area of studies is automotive technology. That is what I am most familiar with.

Re:Transparent aluminum

[digitalunity]

Absolutely. One common example is AlO. Aluminum Oxide. A natural aluminum crystal. However, although metals have the capability to be in crystalline form, they often are not in this fashion naturally. Yes, I wrote my post in a hurry. Yes, I may have karma whored a little. And, finally: Yes, I skipped a lot of stuff and ignored the fact that a crystalline structure does not ensure opacity or transparency. It is an involved factor. I sure struck a nerve! What a troll! whew, that was too much fun.

Yes, glass is not a crystal. Quartz is a crystal, it is transparent. What's your point?

Sorry, I can't help myself. I'm trolling for the big phish now :)

Re:Transparent aluminum

[Swaf]

An intuitive (?) way to see things is that in metals the electromagnetic fields will induce currents that dissipate and reflect the energy of the wave. If I remember well, Maxwell equations actually requires 1) the conservation of the parallel (to the material surface) components of the electric field and 2) the electric field in an ideal conductor to be exactly zero.

Besides all metals are crystalline, even if the size of the crystalline domains (the grains) change according to the conditions of cooling, seeding, etc. Only alloys have been obtained in an amorphous state for extremely high cooling rates.

In general it is not the crystalline or amorphous character of a material that imparts transparency, it is the characteristic dimensions of the material compared to the incident wavelength. If there is a periodicity (crystals) on a scale similar to the wavelength, diffraction occurs, if a random distribution (of particles, domains, ...) exists on the same scale, diffusion occurs. That is why semi-crystalline polypropylene is translucent while amorphous PP is transparent to visible light.

Re:Transparent aluminum

[Prowl]

Are you calling Star Trek IV a thin film?

I thought it was quite profound. Save the whales and all that...

Re:Transparent aluminum

[ewise]

Transparent aluminum (and other transparent armor systems) are an interest of the army.

And here is a picture of a small disc of transparent aluminum

Ahh, Google, my friend.

Re:Transparent aluminum

[CapnGib]

Al2O3 (pure and undoped) is clear. Bulk (polycrystalline) alumina ceramics are "milky white" because of scattering due to crystal-crystal and crystal-air interfaces. The actual particles are clear though. If you get Al2O3 with very small particle size (1 m) it will have a bluish tint, as it scatters blue light more efficiently. By nature, most pure oxides are infact clear. White paint is actually clear. TiO2 particles in the paint are small enough that light is scattered difusely back to the observer.

Re:Transparent aluminum

[withak]

It would have much strength, yet it would fracture easily. Its called "Modulus of elasticity";

No, it's called fracture toughness. Modulus of elasticity is a measure of how stiff the material is.

Re:Transparent aluminum

[Hal-9001]

I hate to dignify this with a response, but an obvious counterexample to this argument is wood. I have never seen shiny untreated wood, no matter how well polished.

In general, surface roughness does affect reflectivity, especially whether the reflection is diffuse or specular, but intrinsic material properties (e.g. metallic bonding [free electrons], band gaps, etc.) are a strong factor as well. The free-electron model also explains why you can't see through aluminum foil but you can see through mirrored sunglasses. The electromagnetic theory of light also generalizes to the microwave radiation that enables the culinarily-challenged like myself to cook, and to radio waves that enable radio, television, and wireless networks. Try patching your "shiny reflective surface" theory to explain all these phenomena... :-p

Re:Transparent aluminum

[markmoss]

I'll try to re-state Hal-9001's post in a little different form:

Electromagnetic waves consist of oscillating electric and magnetic fields in alignment so as to be self-perpetuating. The changing magnetic field creates an electric field a little further on, and the changing electric field creates a magnetic field still further on, etc.

First consider a radar beam approaching a metal surface. The E-field will cause the free electrons in the metal to move. This transfers the energy of the beam into electron motion. And with several pages of math that I went through once and never want to again, it can be shown that the electrons move so as to create a mirror-image field, re-transmitting the beam at the angle of incidence -- in other words, a reflection.

Due to resistance to electron movement, the reflected beam will be somewhat weaker, the missing energy being absorbed as heat. If the metal is extremely thin there might not be enough free electrons to fully absorb the incident beam, so part of it passes through. In an insulating material, electrons are tightly bound to molecules, and so cannot range far enough for strong interactions with the beam, and so most of the beam will pass through (the material is "transparent" to radar). However, electrons can shift around within the molecules, which causes refraction, partial reflections, and absorption.

Things are different for x-rays, because the individual photons are pretty energetic and the wavelength (size of one photon) is close to the size of an atom. So it's more likely to be the inner electrons still bound to the atoms that wind up trying to capture the x-ray, and only rarely does this succeed -- most of the x-rays get through several inches of all but the densest materials.

Visible light photons are in-between in size, large enough to interact well with the free electrons (reflection), but small enough to also be affected by bound electrons. (Selective absorption by the bound electrons gives copper and gold their color.)

Most insulators are not transparent to visible light, except as very thin films. Most insulators (like metals) consist of irregular aggregations of tiny crystals. The interactions with the electrons bound in molecules will reflect some light, absorb some, and refract all the rest. In most insulators, the interaction varies with the polarization of the photon and the angle of the crystal; since each crystal is oriented differently, each interface between crystals refracts and reflects light in different directions, so the light that isn't reflected from the external surface is scattered and (mostly) bounces around inside the material until absorbed rather than passing through.

Most transparent materials are glasses, with no crystal structure, and so no grain boundaries to scatter the light. Single crystals may also be transparent, although it's pretty hard to grow a single crystal as big as a windowpane. Multi-crystalline insulators can be translucent if sufficiently free of the atoms or molecules that absorb light, that is if the light is scattered but not absorbed eventually it will find it's way back out of the material. Concrete could be translucent if both the aggregate and the cement were free of light-absorbing materials, but I think the price would be extremely high.

Possibly a multi-crystal insulator could be transparent if the refractive index did not depend on orientation of the crystal or polarization of the light, and if all the crystals fit together neatly and had the same refractive index. Or use glass beads for aggregate and somehow make the cement match the glass?

Metals by definition have free electrons, which strongly reflect and absorb visible light. If it's transparent, it's not a metal.

You can form Al2O3 into fairly large crystals, and maybe it could be a glass too. It's stronger and much harder than silica-based glass, so it would make a great windshield, if you didn't mind the cost of using diamonds for cutting and polishing.

Re:Transparent aluminum

[Christopher Thomas]

Question - could you make aluminum transparent on some wavelengths by packing it with an array of voids of size comparable to a wavelength of light?

If I understand correctly, this will allow light of a matching wavelength to pass through.

OTOH, if it's more than a few wavelengths thick, it will be very frequency-selecive, so you'd still block virtually all light. And building this extrememely ordered structure is left as an exercise for the reader. I'm just wondering if this or similar patterning would work.

Re:Transparent aluminum

[debiansierra]

umm, using this material would get VERY expensive, it seems.

Re:Transparent aluminum

[gorilla]

Hardness and fragility are two different things. Glass is hard but fragile, as are diamonds. Perspex isn't hard, but is flexabile, which is why it's used for aircraft windows. Unfortunatly this means that every so often the windows have to be polished so that they remain transparent. An ideal substance for windows would be both hard (so that it doesn't scratch) and flexabile (so that it can take knocks).

Re:Transparent aluminum

[Scooter]

"It would have much strength, yet it would fracture easily. "

Hmm a bit like glass then :)

Re:Transparent aluminum

[k-0s]

Jesus Christ, thank god. I was beginning to think I was in an alternate universe where none of the /.'ers had ever seen Star Trek 4. You know, like the alternate universe where the Federation was evil and Spock had a goatee.

Re:Transparent aluminum

[FlatEarther]

Contrary to some comments made about aluminum it is actual fact transparent ! Unfortunately aluminum is largely transparent only to X-rays (and higher energy E.M. radiation). It is not transparent to visible light for the reasons pointed out by other /.ers - i.e. it's a metal & etc. As a small aside, the crystalline structure of a material can and does affect transparency. For example rutile (titanium dioxide) in massive crystalline form is transparent. When crushed to a fine powder and suspended in an appropriate liquid it becomes quite opaque (white paint). On the other hand the PET (Polyethylene Terephthalate) much used to make plastic drinking bottles is usually of low crystallinity otherwise it appears unappealingly translucent or opaque (ie. the consumer cannot see the contents). In both cases the presence of large numbers of small crystals causes the loss of transparency.

Re:Transparent aluminum

[Hal-9001]

What you describe sounds like a photonic bandgap material. I have not heard of metal photonic bandgap or multilayer structures, and therefore, I am not sure whether there is a physical limitation that makes them either impossible or just very difficult to make. You are correct in stating that such a structure would be very frequency selective, and so to the naked eye it still wouldn't look transparent, , but I would also be very curious if something like this could operate at a specific wavelength.

Re:Transparent aluminum

[Hal-9001]

I'm glad someone can explain this stuff a lot better than I can... ;-)

Re:Transparent aluminum

[jthill]

Err, ahh, sapphire is aluminum oxide.

Re:Transparent aluminum

[jea6]

Sorry guys. Transparent Aluminum wasn't available in the 20th Century. Scotty traded Plexico the formula for transparent aluminum for the standard six inch plexiglass:

"SCOTTY
Doctor Nichols, I might have
something to offer you.

NICHOLS
... Yes?

SCOTTY
I notice you're still working with
polymers.

NICHOLS
(mystified)
Sill? What else would I be working
with?

SCOTTY
Ah, what else indeed? Let me put it
another way: how thick would a piece
of your plexiglass need to be at 60
feet by 10 feet to withstand the
pressure of 18,000 cubic feet of
water?

NICHOLS
That's easy: 6 inches. We carry
stuff that big in stock.

SCOTTY
Yes, I noticed. Now suppose -- just
suppose -- I could show you a way to
manufacture a wall that would do the
same job but was only an inch thick.
would that be worth something to
you, eh?

NICHOLS
... Are you joking?

BONES
He never jokes... Perhaps the
professor could use your computer.

[...]

NICHOLS
(wide-eyed)
Transparent aluminum?

SCOTTY
That's the ticket, laddie.

NICHOLS
... But it would take years just to
figure out the dynamics of this
matrix...!

BONES
You'll be rich beyond the dreams of
avarice.

SCOTTY
So, is it worth something? Or
should I just punch "clear"...

NICHOLS
No!
(then)
No... What did you have in mind...?"

Live long and prosper.

Re:Transparent aluminum

[gpinzone]

Now, can you please tell me why it had to be transparent? Would the whales have been upset if they didn't have a view during the ride?

Re:Transparent aluminum

[RetroGeek]

They used 4" pexiglass in the Klingon ship. Scotty gave the formula for transperant aluminum as payment.

Re:Transparent aluminum

[digitalunity]

No, not how stiff it is. Elasticity is a material's ability to be deformed and return to its original shape after the bending force is removed.

Re:Transparent aluminum

[Spock the Baptist]

"Just like Shatner's toupee..."

All to gather now...

(Sung to Prince's Raspberry Beret)

Shatner's scary toupee,
the kind that you get in a second hand store...

Re:Transparent aluminum

[Spock the Baptist]

Ah, Snell!

Someone beat me to the punch!

Re:Transparent aluminum

[Alsee]

[...]

[...]?!?!
I can't believe you [...]'ed "SCOTTY: Hello computer."
That's probably the best line in the whole routine, talking into the mouse :)

-

Re:Transparent aluminum

[Winged Cat]

You're right, but that wasn't the point he was trying to make. People do strange things when concentrating on unusual goals. ;)

Transparent aluminium

[mmontour]

Can transparent aluminium be far behind?

It's already here, although in the form of an oxide rather than the pure metal.

Re:Transparent aluminium

[Cruciform]

So people in glass houses shouldn't throw stones, but people with our new aluminum siding can throw all the stones they want!
On the other hand, neither will want to take showers very often.

Re:Transparent aluminium

[Cptn_Zippy]

Boeing: Hello, Boeing Sales Droid, How can I help you?

Me: Uh, can I get one of those 'Wonder Woman' style airplanes? Preferably with leather seats?

Transparent Aluminium??

[Noodlenose]

...you've been at that Star Trek IV DVD again, haven't you???

Dirk

Transparent Aluminium?

[MoobY]

Aluminium isn't transparent and it's quite hard to change a metal's transparency property (I think it involved some time space continua). so forget about that.

Re:Transparent Aluminium?

[BlueUnderwear]

Aluminium isn't transparent and it's quite hard to change a metal's transparency property (I think it involved some time space continua). so forget about that.

Think cristalline structure. Think additives (it does not need to be 100% pure). After all, we also have transparent graphite, whereas the usual variant is pitch black ;-)

(For the chemically impaired: that's diamond that I'm talking about, which is almost pure carbon, just as is graphite. And as has been pointed out by another poster, transparent aluminium oxyde already exists, it's a synthetic sapphire.)

Transparent Aluminum?

[btempleton]

A little off topic, but germane to the item noted in the summary for this topic.

He refers to transparent aluminum from the Star Trek IV movie. In that film, they risk rewriting history by giving the technology for transparent aluminum to a 20th century factory.

They never answer the basic question of why did the aluminum have to be transparent? Why not regular aluminum or any other such material? Do the whales need a view of the Klingon starship? Do they have no cameras or sensors to let them see the whales?

It made no sense at all but it was a major plot point for the whole film. Sigh. Ok, mod me off topic now.

Re:Transparent Aluminum?

[syrinx]

no no no. they needed *something* to keep the whales in. all they could get was plexiglass. they had no money to pay for the plexiglass. so they gave the guy the forumla for transparent aluminum in exchange for the plexiglass. the factory didn't suddenly start churning out sheets of transparent aluminum (the guy says something like "it would take years to figure out blah blah blah" to which scotty says "yeah but you'll be wicked rich").

Re:Transparent Aluminum?

[wildsurf]

They never answer the basic question of why did the aluminum have to be transparent? Why not regular aluminum or any other such material? Do the whales need a view of the Klingon starship? Do they have no cameras or sensors to let them see the whales?

I wondered about this too, until I realized that the transparent aluminum recipe was simply payment for the normal plexiglass walls they needed for the whales; a sort of barter transaction. The film didn't make this entirely clear on first viewing, but I think this is the logic of the plot.

That begs the question; why did the whales need transparent plexiglass? Perhaps 24th century science has discovered that whales are claustrophobic?

(If the above post is not off-topic, then neither is this one.)

Re:Transparent Aluminum?

[biglig2]

Well, IANAMS* but I imagine (from the name if nothing else) plexiglass is "naturally" transparent - i.e. if you just wander in to a factory and order plexiglass, you get transparent; if you want opaque you need to pay extra and wait longer while they color it.

* I Am Not A Materials Scientist

Re:Transparent Aluminum?

[GigsVT]

I think his point was they could have just gotten a steel tank, for a lot cheaper.

Re:Transparent Aluminum?

[Jtf]

Actually if you watch the movie closely, they do not use transparent aluminum. They use plexiglass. The formula for the transparent aluminum was the payment that Dr. Scott made for enough plexiglass to hold enough water to hold some whales.

Re:Transparent Aluminum?

[GreyPoopon]

Wouldn't the steel tank have been much heavier?

Re:Transparent Aluminum?

[zrk]

Much Cheaper than $0? That's how much they paid for the Plexiglass!

Scotty gave them the molecule for Transparent Aluminum in exchange for the stuff.

Not Now, Madeline!

Re:Transparent Aluminum?

[luiss]

I haven't seen the movie in a long time, but they never said they needed transparent aluminium, they just offered it's formula in exchange for the glass panels.

Re:Transparent Aluminum?

[GUNTHER]

They didn't give the transparent aluminium technology so that they could use it on the ship, they gave it as payment for the plexiglass that was used. They didn't have any 20th century cash. So it made perfect sense.

Re:Transparent Aluminum?

[GigsVT]

Well, you could argue that they "paid" by potentially fucking up the whole timeline by interfering with the past like that. Of course, with all the other stuff they did, it would have fucked it up a whole lot of other ways too.

I never did like that one very much. Sci-Fi time travel into the "present" just seems to me to be a cop out to save money building futuristic sets.

Re:Transparent Aluminum?

[btempleton]

Daresay this is alomst as silly. Changing history in a major way to raise some money? If people came in and offered an invention worth hundreds of millions to get a few thousand dollars worth of plexiglass in a rush, I can't see anybody going for it no matter how good it looked in the computer models.

There are so many other ways they could have raised cash than this (or selling eyeglasses.)

Not the first time this strange plothole shows up in an SF movie, since we saw it again in Star Wars 1, where a Jedi with all his mind powers couldn't find anybody in a whole city who might trade him imperial credits for local currency.

(Note, fun watching how the moderation has gone up and down on my original post!)

Re:Transparent Aluminum?

[GigsVT]

Once you figure in how much thinner it could be, I'd say probably not.

Re:Transparent Aluminum?

[TheLink]

When you add the whales and the water the tank weight becomes rather insignificant.

Don't wait for transparent aluminum.

[Futurepower(tm)]

"Can transparent aluminium be far behind?"

Yes, transparent aluminum can be far behind. Metals like aluminum have free electrons which prevent transmission of light.

Metropolis Magazine Article, April 2001

[bradlauster]

Apparently neither The Economist nor Slashdot knows the difference between translucent and transparent. Ugh.

Anyway, this is old news. Metropolis magazine reported on the development of translucent concrete back in April 2001.

Re:Metropolis Magazine Article, April 2001

[bradlauster]

Uh...forget about that first commment. I was a bit too sleepy when I wrote it.

The link is good though. Check out the Metropolis article.

Re:Metropolis Magazine Article, April 2001

[TheLink]

It's old in the Economist too - came out in the Economist in September.

And if you actually read the article the goal is transparency (good luck ;) ), but for now it's translucent.

"Dr Price is also the first to admit that translucency is a far cry from transparency. His aim is to champion the idea in the hope that fully transparent concrete will eventually become possible. By discussing the notion of transparent concrete, he observes, he gets people thinking in new ways. "As soon as people encounter the term, even people who aren't architects or designers, they are full of desire, full of excitement," he says. He has visions of cities that glow from within, and buildings whose windows need not be flat, rectangular panes, but can be arbitrary regions of transparency within flowing, curving walls."

A good weapon against terrorism...

[heretic108]

would be to legislate that all new residential and commercial dwellings be built from transparent concrete.
Anyone refusing to demolish their existing house would be added to a database of 'potential conspirators'.
This would be quite consistent with recent 'anti-terrorist' surveillance legislation.
Also, the boom in building would boost the flagging economy.
Imagine whole neighbourhoods of people living in complete exposure, proving they're real honest patriotic Americans.

Re:A good weapon against terrorism...

[Jtf]

at least you could throw stones

Re:A good weapon against terrorism...

[kilroy_hau]

Call it something like "big brother", put it on prime time tv and everyone will accept it as normal, healthy fun.

Re:A good weapon against terrorism...

[bigwig10001]

This sounds like the end of The Puppet Masters (the Heinlein book) where they defeat those slugs, but are not sure if they got them all.

The old man says everyone on earth is going to have to wear transparent clothes from then on (or for 75-100 years or something).

I'm going to regret this...

[iangoldby]

I wouldn't want to live in a transparent house. Think of the lack of privacy. People'd be able to see when I was in the bedroom, when I was in the bathroom... They'd be able to see all my movements.

Re:I'm going to regret this...

[ryanb100]

It would make great viewing, didn't the spanish try something like this? ie a glass house with convenient viewing galleries for the leering dirty old men ( you'll notice that they populated the house with nubile young women) sorry a bit off topic there

Re:I'm going to regret this...

[hazem]

At least then we could get rid of the whole "those who live in glass houses shouldn't throw stones" nonsense. When your house is made of transparent concrete, you could throw all the stones you like!

It might be something like, "those living in transparent concrete houses shouldn't drive wrecking balls"!

Re:I'm going to regret this...

[ralmeida]

Do you know why did the blonde climb the concrete wall?

To see what's on the other side.

Re:I'm going to regret this...

[biglig2]

But if it was made out of transparent concrete you could at least throw all the sotnes you wanted...

Re:I'm going to regret this...

[ThePilgrim]

IIRC they started of with men in the house, but that didn't attract crouds so they switched to females.

Re:I'm going to regret this...

[Phrogz]

What, you mean like Philip Johnson's 'Glass House' (1949, New Canaan, CT)?

Oh yeah, and: LOL. Potty humor...is there nothing funnier? :)

Re:I'm going to regret this...

[PyroMosh]

Ewwwwww....

I have a feeling that this guy would love it though.

That's a scarry thought. Real life trolling through building materials.

Re:I'm going to regret this...

[jx100]

People'd be able to see when I was in the bedroom, when I was in the bathroom... They'd be able to see all my movements.

I don't think anyone would want to see your "movements" in the bathroom. Unless they had some sort of fetish or something...

interesting idea

[Hadlock]

although right now it sounds more like Plexi glass or a liquid epoxy of some sort. kudos to the marketing rep who associated it with concrete.

on the other hand, at my old middle school, the school had outgrown it's original gym, and elected to build a second gym away from the main building, made entirely from concrete. I never understood how that thing stood; it was full-sized, housed a cafeteria in one end, and above that was the wrestling mat. to get to the point, it was abysmally dark in there. they had xeon HID lamps or the likes in there, and things were still pretty dim. emergency lights would no doubt have poorly lit it also. making the east and west walls semi-translucent would have significgantly improved lighting conditions.

i wonder if you could put an element in this "concrete" that would block IR light, otherwise I can't see this being implimented in the south or very far north, as it would cause massive heat-loss/absorbsion.

Transparent != Translucent

[Osty]

There is a very big difference between "transparent" and "translucent". The former means that light passes through the material almost completely unchanged (a certain amount of distortion is okay, but the point is that you can make out what's behind it). Translucent means that light is transmitted, but it's diffuse and you can't make out what's behind the material. This concrete is translucent. It's not transparent (read the article).

Re:Transparent != Translucent

[premier]

Hey numbskull, the article states that he has develeoped translucent concrete, and is now working to develop transparent concrete.

As you said yourself, READ THE ARTICLE.

Re:Transparent != Translucent

[Stripsurge]

I think the best way to describe translucent is giving the example of Lego. You know the "clear" ones? But you can't really see through them.

Re:Transparent != Translucent

[hashashin]

Still, I think it would be cool to be able to paint a stained-glass window on your wall, and when the sun shone on it from outside, it would glow. :)

Mod up please

[CoreyGH]

Syrinx is exactly right! I can't count the number of times I've had to correct would-be nitpickers about this.

Transparent building materials

[Hougaard]

The real problem with transparent building materials is that people inside want to control the transparency, just look at your own home, you got curtains and shades on all(most) windows.

A classic problem with new hightech buildings (Glass 'n metal) is climate control, its nice to be able to look outside, but if the sun is starring you right back its not that fun. So you tint the windows :)

The next problem is that in those buildings the light that gets through is not white light (sunlight) anymore, and working in that kind of buildings can cause depressions very similary to winter depressions.

Remember: Architects are just building nerds :)

Re:Transparent building materials

[Hal-9001]

It's a shame that electrochromic windows haven't taken off. I first read about them in Popular Science, probably about 10-15 years ago, and if I recall correctly, they were used in a concept car by Ford (I could be mixing two Popular Science articles together), but they allow you to electrically darken and lighten windows, and they actually reflect light and heat (unlike liquid crystals, which just scatter light and heat but still let them through). I'm not sure, but they might also be wavelength-independent, i.e. reflecting all colors of light equally. The obvious barriers to their widespread adoption are probably cost and the ability to make panes large enough to use as windows.

Re:Transparent building materials

[Hougaard]

Well I'm from Denmark, so you will have to forgive my english.

... and I think that my english is better than your danish :)

Re:Transparent building materials

[PsychoKiller]

They exist, but I'm not sure how large they can get. Some fancy arc/mig welding helmets have them connected to the welder, so when you start welding, the glass darkens and you don't fry your retinas.

Much easier than flipping the helmet up and down all the time.

Re:Transparent building materials

[mcjulio]

Research Frontiers is still working on a technology of this type using suspended particles sandwiched in a pane of glass that dim based on voltage. They've shown signs of doing great things over the years, but haven't yet made a dime.

On the upside, if you trade their stock, you can truthfully boast that you buy and sell REFR.

Re:Transparent building materials

[Saeger]

So bring the white light inside.

I recently replaced almost all of the incandescent and standard flourescent bulbs in my place with VITA-LITE's, and I can't tell you what a huge difference it has made. It honestly feels like you're sitting in a sunlit room... (and the energy savings is nice plus too).

--

Re:Transparent building materials

[srvivn21]

Expense not size is the deal breaker.

For the paranoid, this is an article describing "the San Francisco bachelor pad owned by the bad boy of high tech, Larry Ellison, chairman of Oracle":

A visitor's experience begins at the front door, a half ton of stainless steel with an inch-thick pane of opaque electrochromatic glass. "When you turn the doorknob, a 125-volt charge makes the glass transparent so you can see the Japanese rock garden on the other side," Green says. The unusual glass alone costs about as much as a high-end Mercedes.

Re:Transparent building materials

[hashashin]

Bar 89 in New York has bathroom stalls that work like this.

When the stall door is ajar, the walls are transparent, and the unexpecting think everyone will be able to watch them crapping. But when you latch the door, your stall becomes opaque and you need not fear.

Re:Transparent building materials

[llamalicious]

actually... while they haven't made huge inroads (due mostly to their high cost) electrochomatic fixtures have been placed in a variety of higher (and now lower) end vehicles.

Generally, these are limited to side mirrors or your rearview mirror, they are setup up with a photosensor that increases (or decreases) the charge applied to the glass when direct lighting is applied. (e.g. the idiot behind you has their high-beams on, your rearview darkens)

of course, this is all quite off-topic, let the modding begin!

Re:Transparent building materials

[Hal-9001]

Given that the story kinda veered off-topic by mentioning transparent aluminum, the abundance of semi-off-topic threads should not come as a surprise. I myself consider electrochromic materials to be way cooler than translucent/transparent concrete.

huh ? clue me in please..

[BobSoros]

can someone explain to me what the writer of this story meant when they said "can transparent aluminium be far behind?" (i think he meant translucent) What does alumunium have to do with concrete ? Did i miss a joke ?

Re:huh ? clue me in please..

[Anonymous Coward]

Please see Star Trek IV: The Voyage Home

Scotty gave a company the secret of transparent aluminum in exchange for a tank large enough to hold two whales.

Re:huh ? clue me in please..

[Rhinobird]

Yes you did miss the joke. Go watch Star Trek IV, this will give you the cultural reference to 'get' the joke.

Re:huh ? clue me in please..

[BobSoros]

thank you thank you, now i remember.. truly one of history's worst films (not a popular opinion around obviously.) The :NG films were great but anything with Shatner was a complete fucking joke IMHO.

Re:huh ? clue me in please..

[spitzak]

The joke was in Star Trek IV. They had time-travelled to the present day and were trying to build something, and were wondering what materials the primitive present-day Earth had. One character (?who?) said "what about transparent aluminium" and the other (scotty?) said "they don't even have *that* yet".

Is it really concrete?

[Eminence]

Can material described in the article really be called "concrete"?

As it is written there its only resemblance to concrete is that it consists of coarse aggregate, fine aggregate and binding agent. But this is not a recipe for concrete only - also for other materials. Also, Dr. Price's secret material can't be poured or produced on site - one the main reasons of traditional concrete popularity. It would probably find its use in form of blocks of translucent material, that could be used to enhance possibilities for architects but what Dr. Price is trying to do is another building material, which is very interesting indeed but can hardly be called "concrete".

Re:Is it really concrete?

[Hal-9001]

From the story:

Technically, concrete is simply a mixture of three ingredients: big lumps of material called the coarse aggregate (such as gravel), smaller lumps called the fine aggregate (such as sand) and a binding agent, or cement, to glue it all together into a solid. So translucent concrete, in theory, should be fairly easy to make using bits of plastic or glass of various sizes, with some kind of transparent glue to act as a binding agent.

This sounds more like a composite than concrete to me. The Dictionary of Composite Materials Technology defines a composite as

A multiphase material formed from a combination of materials which differ in composition or form, remain bonded together, and retain their identities and properties. Composites maintain an interface between components and act in concert to provide improved specific or synergistic characteristics not obtainable by any of the original components acting alone. Composites include: (1) fibrous (composed of fibers, and usually in a matrix), (2) laminar (layers of materials), (3) particulate (composed of particles or flakes, usually in a matrix), and (4) hybrid (combinations of any of the above).

By this definition, "transparent concrete" is a particulate composite of plastic or glass, probably in a matrix of epoxy or resin. Concrete is also a composite by this definition, but despite what my civil engineering friends might try to tell me, that doesn't mean that all composites are concrete. ;-)

Re:Is it really concrete?

[PD]

But this is not a recipe for concrete only - also for other materials.

Yes, it is also a recipe for meatballs.

Re:Is it really concrete?

[Kanasta]

You've just said that concrete is a composite, which is correct.

You note that concrete is a specialised form of composite (particulate composite).

This doesn't their definition is wrong.

Might be a bit general tho. Most people expect the coarse aggregate in concrete to be gravel and the fine aggregate to be sand.

Re:Is it really concrete?

[Hal-9001]

Any reasoning that classifies this mixture of "plastic and glass beads and transparent glue" as concrete would also classify fiberglass and carbon-fiber as concrete, and that definitely does not sit well with me.

Re:Is it really concrete?

[dublin]

This is clearly an aggregate composite (the "particulate" term is also accurate, but not one I've heard before, and I worked for years with automated manufacturing of advanced high-temperature aerospace composites - "aggregate composite" was always used in the books to describe concrete.)

More importantly, though, I haven't seen anyone zero in on the single thing that I would think would categorize an aggregate composite as a member of the "concrete" family: the use of portland cement or other finely powdered clay substance as the binder and activator. Concrete is generally ugly, but it's pretty amazing stuff. Much of the modern world could not exist without the use of something so strong and cheap as steel-reinforced concrete.

Light Pollution

[zephc]

Buildings glowing from within? This is terrible for astronomers... the added light pollution would further ruin the viewing conditions for many great observatories.

Re:Light Pollution

[redcliffe]

Then you'd have a bunch of extremist astronomers going around commiting a terrorist war against light pollution. :-)

Re:Light Pollution

[foobar104]

Buildings glowing from within? This is terrible for astronomers... the added light pollution would further ruin the viewing conditions for many great observatories.

Maybe that wouldn't be so bad. I say, the sooner we got astronomers off the surface and up to the far side of the moon, where they belong, the better.

a new adage...

[ism]

People in concrete houses should not throw stones?

Not impossible

[heikkile]

Can transparent aluminium be far behind

After all, most of us are reading this through a good chunk of transparent mixture of lead and sand! Yes, good quality glass used for CRT displays...

Unbelievable

[jquirke]

I can't believe we've made it this far without a debate on the spelling of Aluminium.

--jquirke

Hello, Computer!

[VValdo]

What I find most amazing is he models the molecules on like a Mac Plus, if I remember right (haven't seen it since it came out)...

Imagine what he coulda done w/a g4. You say "Hello, Computer" and it actually listens!

W

Re:Hello, Computer!

[GreyPoopon]

What I find most amazing is he models the molecules on like a Mac Plus, if I remember right (haven't seen it since it came out)...

Mod me as off topic if you like, but that movie was released in the grand era of the Commodore Amiga. I vaguely remember reading in one of the Amiga rags that they had originally intended to use an Amiga as the computer, but Commodore was behind in their shipments of the A2000. Some nutball decided that they were going to satisfy requests in the order they were received. Obviously, Star Trek producers weren't interested in waiting. I wonder if somebody got fired over that decision.

Perverts!

[jonr]

What next? Transparent curtains?

Re:Let me sum it up for you

[DCowern]

Do slashdot editors read the articles before posting them?

Do people posting about slashdot stories actually READ the entire thing before posting? If you had you would have noticed that the comment about transparent aluminum was not made by michael but by the person who originally sent in the story.

Glass Houses

[Perdo]

If you lived in a transparent concrete house would you still have to refrain from stone throwing?

Re:Glass Houses

[Lord Bitman]

No, but that other rule about getting dressed with the lights out still applies

Re:Glass Houses

[markmoss]

No, but if you look like my wife the neighbors will all demand an ordinance requiring you to remain fully clothed at all times...

Re:Glass Houses

[Perdo]

Jesus man, you can't just make a comment like that on /. without leaving a link to pictures.

Re:Glass Houses

[Decimal Dave]

If "People in glass houses shouldn't throw stones" is good advice, then we might also assume that "People in stone/concrete houses shouldn't throw glass" is also a solid recommendation.

I've conducted a small experiment to test this assertion and it turns out that it is, in fact, true. As a side-effect my parents have now strictly forbidden the throwing of both glass and stone in our house, even though the building is not transparent nor made of glass.

Re:Glass Houses

[Peter Harris]

His ex-wife, if she reads /. ?

Re:Let me sum it up for you

[vidarh]

The comment about aluminium is a reference to Star Trek.

Remember the "clear craze" several years ago?

[Ukab the Great]

First we had clear Pespi.
Then we had clear deodorant.
Saturday Night introduced us to clear gravvy.

Like clear concrete was that far behind?

I know how this one started...

[Andy_R]

Architect "...are the stairs, and this is where the wi..."
Programmer "NO! NO! I will not have windows installed!"

Re:I know how this one started...

[GrayWing]

Easily solved... install X-shaped windows. Voila - an X Window system.

Re:I know how this one started...

[Decimal]

Doesn't have quite the same ring to it... "Microsoft Transparent Concrete".

Re:I know how this one started...

[Andy_R]

Don't forget that Apple has 2 alternatives... Carbon (in it's transparent form, this is a very 'apple-esque' solution... better in almost evety way, but horribly expansive) and Aqua (cool, transparent, but rather unstable for real-world applications)

Are you sure?

[supernova87a]

I have to agree here -- I don't think that crystalline structure alone will confer transparency on a material, especially metal. It has firstly to do with the properties of the atoms and molecules themselves, and maybe second the crystalline nature.

Why, then, would glass be transparent? Glass has a most uncrystalline structure!

Re:Are you sure?

[Hal-9001]

I have to agree here -- I don't think that crystalline structure alone will confer transparency on a material, especially metal. It has firstly to do with the properties of the atoms and molecules themselves, and maybe second the crystalline nature.

Why, then, would glass be transparent? Glass has a most uncrystalline structure!

Doh! Why didn't I think of that obvious counterexample? ;-)

Re:another gibson prophecy!

[kfg]

I'd say just about every one, along with all sorts of other wonderous materials to further either the plot of the "gee whiz" factor of their stories. What's more, "inventing" the idea for such materials is pretty easy. You could do it yourself all day.

"Gee, wouldn't it be great if there were something 10 times stronger than steel a 1/4" thick sheet of which could sheild a person from an atomic blast and a whole boxcar full only weighed about a pound and a half?"

By the way, *glass* is stronger than steel by a good margin.

KFG

If transparent concrete becomes a reality...

[maroberts]

..the mafia will have to find other places to bury people like Jimmy Hoffa!

Re:Won't someone think about the mob?

[3Suns]

But then again, "Glass Slippers" sounds so much better than "Concrete Overshoes".

Glass

[Sprunkys]

and buildings whose windows need not be flat, rectangular panes, but can be arbitrary regions of transparency within flowing, curving walls.

Sorry, but that is already possible.
A researcher at the university of Delft has developed a way to create twisted glass allowing for twisted buildings.
A dutch article can be found here. Take a look at the images if you don't understand the text

Re:Glass

[Ozan]

A researcher at the university of Delft has developed a way to create twisted glass allowing for twisted buildings. A dutch article can be found here [tudelft.nl]. Take a look at the images if you don't understand the text

I had an internship in a firm that processed glass to bend it. See here under 'free form bender'. Other forms as shown there are possible too. The biggest disadvantage is that glass processed this way is very difficult to handle, once a two m window burst into million pieces just when it slightly touched the floor accidentaly when it was being carried. Imagine the trouble you will have fitting out a whole skyscraper with these.

Re:Glass

[Sprunkys]

- Log in
- What about costs? The parent article of this discussion discusses costs that are 5 times higher than (oh, btw, check then vs. than) normal concrete, how is that with this kind of material?

But if someone DOES get encased in it...

[AndyChrist]

On the upside, if anyone tries it, my curiosity as to what such a corpse looks like after a few years will no doubt be satisfied.

Re:But if someone DOES get encased in it...

[Drakin]

Why do I get this image in my head now... upon the first body found in trnsparent concreat...

Guy - Hey, what's that in there... a body?
Modbster type - No see... it's a work of art, to give the place a more... casual appearanc .

mimes do make a sound

[Ali Graham]

maybe mimes actually make lots of sound , but maybe they are just trapped in big trabsparent concrete cubes ?

we're all smurfs.

[neoform]

He has visions of cities that glow from within, and buildings whose windows need not be flat, rectangular panes, but can be arbitrary regions of transparency within flowing, curving walls.

Hmm, maybe we could all live like smurfs in giant mushroom houses.. i mean.. what the hell is he thinking? how do you expect to make non rectangular windows....? maybe this can be used in one of those 'art houses', you know, those ones with the 20' steel doors, and the giant gargoiles and the 'modern art' paintings consisting of black and only black ("I call it, city.. at night!").

Bathrooms

[Molina the Bofh]

I just wish they'll be able to achieve this great feat of engineering: Transparent female bathrooms.

Go, scientist, go.

Big Brother

[JohnHegarty]

Hope they have this ready for the next series of big brother....

Blend of two transp. materials is not always ...

[marcovje]

The explanation on how to achieve this reads a bit funny.

It seems to assume that if one mixes two transparent
components (e.g. glass grid, and some transparant matrix), the result is also transparent.

This is not true, as every high school boy that studied optics can tell you. Refraction index, surface properties etc.

It will probably be pretty hard to make a transparant material from two components, let alone keep the other properties of concrete.

Insulation

[Zanzadar]

Here is a question that seems to have gone unasked, what are the insulation properties of this new material likley to be?
It seems to me that concrete is a pretty good heat conductor and that this new material being made of a mix of glass and plastic and 'glue' might be okay (glass is a good heat conductor, but plastics tend to be a pretty good heat insulators). Also controlled air bubbles could add to this insulation, and reduce weight where strength is not required.
This could save alot of money and help build more energy efficient buildings (not to mention the cheap light source, ie sunlight)
Now here is another thought, how about 1 way translucent concrete, let the light in, but not out?!? (Well just a thought)

Recycle

[ONOIML8]

The article mentions that the doctor wants the material to be able to recycle. The author comments that this might be a "tall order".

This tells me they must be using some VERY uncommon bonding agent. They do mention the use of glass, which is a sand product anyway, being used.

It's hard to imagine why they couldn't recycle this stuff like they recycle concrete now. It makes me even more curious as to what their formula is.

Edible Concrete

[Anonymous Coward]

Edible concrete has been with us for years:

coarse aggregate - dried fruit
fine aggregate - flour
binding agent - eggs.

It proved so popular, it's got its own name - cake!

Let's face it, Marie Antoinette would've looked a bit of a dork saying "let them eat edible concrete."

Re:Edible Concrete

[Brendor]

Not to be confused with the honey, apple and rasin mortar of the passover tradition.

How are they related?

[ONOIML8]

Ok, I'm just a dumb radio/computer geek and gearhead. Pardon my stupidity here but:

How would development of translucent or transparent concrete be related to the development of a transparent aluminium?

I've read everything in the discussion so far and still fail to understand. From what I've read so far the making of concrete is a very different process from making aluminium, which is just what I would have imagined.

So why would reading the article in the Economist cause someone to wonder about the creation of transparent aluminium?

Re:How are they related?

[Legion303]

They aren't related, except by the word "transparent." Michael thought he was being clever by making a Star Trek reference.

-Legion

Re:How are they related?

[Legion303]

Michael thought he was being clever

My mistake--it wasn't Michael, but the contributor who thought he was being clever.

-Legion

+1 Insightful on the MQR standard

[MarkusQ]

An AC wrote:

Edible concrete has been with us for years:

coarse aggregate - dried fruit
fine aggregate - flour
binding agent - eggs.

It proved so popular, it's got its own name - cake!

Let's face it, Marie Antoinette would've looked a bit of a dork saying "let them eat edible concrete."

I haven't any real mod points, but this AC post deserves notice in the context.

-- MarkusQ

Yep, he's right.

[Evil Pete]

Can't happen.

Metals are a "sea of electrons" right ? Basic stuff. When a photon hits it these electrons are responsible for reflecting the particle. And you get basic "skin effect" penetration inverse exponential. It aint possible except in very thin layers. Like gold that can be beaten so thin as to be transparent.

If you get transparent aluminium it'll just be a dielectric not a metal.

Much more informative article

[bdavenport]

this april 2001 edition of Metropolis has a pretty informative article on the man and his background.

interesting that i live in houston (concrete captial next to LA) and never have read an article on this guy.

Lens and the Sun

[Paul Johnson]

I can see a whole new collection of risks here, especially if there are any curved surfaces involved. At various times of the day a transparent product would focus the sun's rays into various hotspots. Some of these might be intense enough to cause burns or even fire. The lenses would not be terribly efficient, but they would be very large.

Paul.

Re:Lens and the Sun

[Malc]

It would also certainly cause increased colour fade of items within the building, even if they don't get that hot.

Re:Lens and the Sun

[SIGFPE]

Good point. There are a great many hazards associated with transparent building materials and for some years now I've been campaigning to have them curtailed or even removed from building entirely. One such material is glass and the hazards are well known: risk of fracture, the ease of accident causation (eg. walking into glass doors) and, as you point out, risk of fire due to caustics produced by the curvature of glass. There are other more subtle risks such as the yearly loss of revenue due to espionage caused by the fact that just about every company has great big transparent regions in every room allowing spies to look in using binoculars (which themselves are testament the hazards of allowing the public free access to transparent materials).

To add to these risks the hazards associated with translucent or transparent concrete is surely foolhardy. We already have far too much transparency in our society and it's time to bring this madness to a halt.

Re:Lens and the Sun

[5KVGhost]

The lens aspect may be new, but the problems associated with lots of transparent surfaces appear to be largely ignored by architects who place appearances above practicality (in other words, most architects.)

I understand that many large buildings with glass curtain-wall construction already have serious problems with heat buildup inside. They look pretty on magazine covers, but the people inside quickly realize that they're gonna bake whenever the sun shines. And the windows can't be opened, of course, because that would be wrong somehow. The "solution" is lots of venetian blinds covering up the windows.

You also have the obvious problems with lack of privacy, and the fact that any necessary and useful objects visible through the giant windows (like desks, wires, etc) will look really ugly from the outside.

Re:Lens and the Sun

[PsionicMan]

And the windows can't be opened, of course, because that would be wrong somehow

Office building windows can't be opened because of disasters such as stock market crashes. Stock market crashes make people jump out of openable windows. (It's not limited to stock markets crashing, either: how much you want to bet some Enron folks would have taken a leap?)

I think it's stupid too, but there it is.

--Psi

Doesn't glass...

[GodSpiral]

cost about 5 times more than concrete, is made offsite in pre-fabricated blocks, has exceptionally vivid transparency, and is available today.

Granted, its probably a lot more than 5 times more expensive, but if cost is a concern, and you will settle for the bear minimum of translucency, use plastic.

I've lived in a house with too many windows, and its hell. You would not want every outside wall in your building transparent. If only because furniture is designed to have its back hidden.

lost i

[Gonoff]

The i only got lost on your side of the Atlantic chum. On this side we have aluminium. It goes with Sodium Ammonium and lots more.

The LCD variety has been done

[swb]

I think by either Marvin or Pella. I've seen promotional materials, and IIRC it was a kind of transparent LCD panel that could be opaqued or made mostly transparent. The downside is that I believe it took power to keep the window transparent, and it was really expensive.

Either way, modern windows, according to my wife who used to work with Andersen Windows, have a higher R factor than a lot of walls -- triple glazing, low emissivity coatings, and krpton/argon filled voids go a long way.

Re:The LCD variety has been done

[A nonymous Coward]

modern windows...have a higher R factor than a lot of walls

Not bloody likely. Even triple pane windows aren't much more than R-3 or R-4, even if you add in Low-E and all that, you don't get much more. 6" walls (USA) easily get R-38 with insulation. Maybe if you had simple plank walls your windows would be higher.

Make up our mixed-up minds

[sunhou]

I once heard a comedian describe a house as something like "to distance ourselves from the world, we build houses to live in; to get closer to the world and know what's going on outside, we cut holes in the walls; to separate ourselves again, we put glass in the holes; to feel closer to outside, we make the glass slide up so it's out of the way again; to separate ourselves, we hang curtains to block the holes in the wall; to be closer to the world; we slide the curtains out of the way -- let's just make up our mixed up minds already!"

Transparent or translucent aluminum might save us a step or two.

Rebar

[rootmonkey]

Just because you have see through concrete doesn't mean you will have see through walls. Those concrete walls,bridge etc don't standup by themselves, they are filled with re-enforcing steel. However if they get the fiber glass strengthed concrete stronger then maybe.

Useless News aimed at Bank Loans

[dnoyeb]

Why tell me now? How much closer are they than they were 50 years ago??? When you develop something, call me.

Is it Cheap Enough to Fake?

[4of12]

No, really!

If high quality displays can be made inexpensively, of flexible material, and incorporate light sensors (presumably not overwhelmed with photons emanating from the display), would it not be possible to use them as wall paper on the inside and out and thereby achieve the illusion of transparency?

you'll be wicked rich

[caduguid]

You'll be rich beyond the dreams of Avarice!

Re:you'll be wicked rich

[syrinx]

yeah that's it. well if scotty had been from new england, he would have said "you'll be wicked rich." :)

Re:you'll be wicked rich

[jx100]

I thought McCoy said it?

Transparent Alluminium???

[sydneyfong]

Just imagine what Steve Jobs would do with his iMac cases...

Back to the future

[Anonymous Coward]

The quest for transparent buildings is eternal among deigners, eternally rejected by building occupants (for the most part). After all, who *really* wants transparent waste lines? Not to mention walls are not uninterupted monolithic entities-there are all sorts of utilities in walls. As a *real* architect ("brick and mortar"), I've seen this sort of fad before, but it is hideously expensive to achieve and can only be done in specialized buildings, not general use. Not to mention, these types of buildings often do not weather well.

Transparent Houses

[mencik]

If they achieve transparent concrete (not likely IMNSHO), then people that live in transparent (glass) houses WOULD be able to throw stones!

New phobias

[MrIcee]

Oh great... NOW I have to worry about driving over TRANSPARENT BRIDGES? :)))

Re:New phobias

[Hydro-X]

Ever been to Montreal? I think it's the Victoria Bridge that the deck is made entirely from a steel grill of some form. I've gone over it on a train (it's a rail bridge with vehicle lanes on either side of the track) and every time it just freaks me out looking down on it. I could never imagine driving on something like that, but last summer my uncle took me out for a drive around town and we crossed that particular bridge. Because of the angle you see the deck at over the hood of the car, you can't see below. (Of course, he drives a 91 Hyundai or something of the like, so you're not too high off the ground to begin with..) The wire grate makes all kinds of noise on the tires however. There must be huge chunks of rubber on the floor of the St. Lawrence river because of this bridge...

What's taking them so long?

[16977]

From what I remember, transparent aluminum was supposed to be invented sometime in the '70s.

Re:What's taking them so long?

[Dr Fro]

It's the year 2000 and I was promised flying cars!!!

Potential for Recycled Materials

[NeuroManson]

I've calculated a possible material to use for the binding agent, that's a no brainer: Silicone (as it can be formulated for varying degrees of clarity and density)or fiberglas epoxy resins (the added bonus of this is fairly rapid curing...

However, the ecological impact is a far better thing to consider... For example, recycled bottle glass can be ground down to make both aggregate and filler (you can seperate the colored glass and use that to add a touch of color to the finished product), and ground further down, it can act as filler as well...

Considering that the majority of states in the US only have voluntary glass recycling, it might provide incentive for deposit glass bottles, not to mention finally provide a real incentive to recycle old CRT's...

Or if you're feeling daring, you can use the same optical quality sand they use for reflective road striping to give the concrete an almost luminescent quality... For added strength, use polycarbonate rods or strips in a woven lattice...

The article stated that transparent/translucent concrete can only be prepared offsite, but in theory it can be done the same way as existing concrete, just bring a lot of drums of resin or silicone to the site...

Translucent homes

[ajiva]

People in translucent concrete homes shouldn't throw rocks

Re:Translucent homes

[funwithBSD]

AH no, that is the point, now they won't be able to throw thermo nukes, but rocks are Ok.

Not to mention, how are our papers going to get delievered if young boys don't have to pay for the window they broke with the baseball?

Transparent Office Building - Peeping Execs.

[akiaki007]

That's going to be the next headline. They'll design something like the Jacob Javits Center, and then we'll see transparent floors, and next thing you know, all the execs get sued for sexual harrasment because their secretaries all had offices on the floor above them, not next to them. And for some reason they had to wear skirts...go figure.

You will never see transparent aluminum...

[Mad Man]

The reason you will never see transparent aluminum is not because of a lack of crystalline structure...

The real reason you will never see transparent aluminum is because it is, well, transparent.

Re:You will never see transparent aluminum...

[quantaman]

It's already here! They just haven't started producing it yet because they haven't yet perfected the formula that Scotty gave them! Cm'on haven't you seen Star Trek: The Voyage Home!

Seeing through walls?

[aoliva]

I thought it was Micro$oft who invented the ultimate device to see through walls. didn't Bill Gates call them Windows?

How to tell for sure

[Hell O'World]

I would be willing to stretch the definition to include this new material... IF it is also structural.

Hm, tastes like concrete.

Hm, feels like concrete.

Hm, The way this bridge is wobbling makes me think maybe it's not real concrete.

HMN Alert!

[msouth]

I'm sure the moderator just slipped, and meant +1, funny instead of -1 offtopic. How come I never see these guys in meta-mod?

We need some kind of catchphrase for moderation like this. Humorless Nazi Moderator or something. Then we can reply to posts like this with "HMN Alert" or "Dude, ignore the HMN, I thought it was funny."

alpha channel

[profke]

Hope their server supports alpha-channels. :-) This gives a whole new meaning to bump-mapped walls...!

Transparent walls, privacy, and science fiction

[ajna]

Taken to the logical extreme (where everyone has transparent houses) then we'd have the world of Yvegeny Zamyatin's We. I for one don't want this, and fail to see how more transparency will change the world. Perhaps we'll get an interesting new concert hall out of this (a nice change from halls clad in titanium, such as the Guggenheim museum in Bilbao, Spain) but what else?

Fire resistant? Or toxic smoke as it burns?

[Derek Pomery]

Don't see it mentioned anywhere in the comments yet, but after reading the article, the first thing that concerned me is that the nice thing about a concrete building is that it will hold together when it catches fire, not melt, puddle, and add to the blaze with choking poisonous smoke.

Hopefully the designer is taking into account other properties besides strength.

Another, longer article on the same subject

[curtisg]

http://www.metropolismag.com/html/content_0401/shu lman/

Using "Zappi" as a replacement of steel

[rigolo]

In The Netherland professor Mick Eekhut is doing research into using glas like building materials.
He calls his "glass" Zappi and you can find some more details here
Here is an abstract:

Abstract
Glass is not generally used for loadbearing building components. The primary reason for this is that once the failure process starts in a glass component, the cracks run throughout the entire component. As a consequence the component fails completely in its loadbearing function. This is generally resolved by using metal components in the design that serve as a backup.
For architectural reasons the use of metal components is not desirable while the presence of metal components designed to carry all the loads if the glass fails, obviates the need for a loadbearing function in the glass.
To resolve these problems a hybrid glass/polymer composite system has been developed. Special tempering treatments have been developed to increase the toughness of the glass. In addition a method of combining the specially tempered glass with polymers has been developed. In combination these processes give the following properties :

• structural engineering properties comparable with aluminium.
• reduced chance of crack initiation and crack propagation in the tempered glass.
• high residual strength of the component after accidental damage.
• slow progressive collapse of components if damage exceeds a certain criterion allowing for sufficient time to evacuate the building.
• very large components are possible

The resulting system has the advantage of allowing complete transparency, while having adequate strength, stiffness and safety to compete with metals while the increased architectural possibilities outweigh the cost of the components.

Rigolo

So what you do is weave it

[HiThere]

It might be possible the take a bunch of really thin threads of aluminum and weave them into a mat, which you then embed into a matrix of pale sapphire. Perhaps the metalic threads would enhance the flexibility of the sapphire, while still being thin enough to allow for transparency. The problem that occurs to me is that I believe that sapphire usually solidifies at a higher temperature than aluminum. So keeping the mat intact might be a real challenge.
.

Please parent mod up, and mod down OP

[Malc]

Thank you AC. When I read the article, it was very clear (pun not intended!) from the beginning that they were aware of the difference. This is The Economist: they might simplify technical subjects, but they rarely make such obvious mistakes. And just to quote one part of the article:

"Dr Price is also the first to admit that translucency is a far cry from transparency. His aim is to champion the idea in the hope that fully transparent concrete will eventually become possible.

The Mafia

[scheming daemons]

The mob won't like it. Where would they hide the things like Jimmy Hoffa's body?

Ewww....

[scheming daemons]

Think of all the creepy-crawly things that would be seen through concrete sidewalks and driveways. Or through the walls of your basement? Yuck....

I don't want to even think about mausoleums.

Too bad Enron didn't use transparent concrete

[LM741N]

Then everybody might know what really happened there!

Clear Concrete - Very Scary!

[kninja]

Is anyone else afraid of something like this? using plastic instead of steel to reinforce a building made of some new kind of concrete. I for one will not set foot in such a building... I have visions of galloping gerdie... (the bridge in Washinton state that wasn't tested enough)

"We"

[jabber01]

"We" by Yvegeny Zamyatin, written in 1927, is a precursor of Orwell's 1984. It's a classic dystopic novel, which features, among other things, transparent dwellings for exactly the purpose you suggest.

Re:"We"

[bishma]

You beat me to it. I just got done rereading We a couple weeks ago, and I find this article a little scary... especailly with some of the Orwellian stuff happening these days.

Hmm....

[Restil]

Glass houses that are golf-ball resistant.

And tornado resistant.

Heck, even crowbar resistant. That's right Milo, keep whacking on that window, we'll get in eventually!

-Restil

Re:I may as well say it....

[Explo]

Sounds more like light pollution ensuring that no-one will ever see any stars within cities...

Re:transparent aluminum exists; used for rockets

[Nonillion]

Can you provide any links? I'd like to check this out...

rm -r windows

aha

[Hadlock]

i just thought of a neat idea for translucent "concrete".... a big long line of white (superbright, maybe?) LED's, spaced about 18" apart, much like lane dividers of old. add in some refraction properties (the aggrigate substance), and you have an illuminated lane marker....oh wait, you could do that with clear epoxy resin. isn' t that just what "transparent concrete" is going to be? maybe apple should hire his marketing rep.

She said her love for me was concrete...

[cburley]

...but I could see right through it.

Re:I may as well say it....

[wsloand]

He has visions of cities that glow from within...

Perhaps he has never seen the city glow that comes from normal light pollution.

Speaking of which... a mystory

[SONET]

I know this is a little off-topic, but here's an unsolved trivia question I've had for a few years that nobody has been able to answer...

If you have ever been to Disneyland (Calif, USA) and been to the Star Tours attraction, when you get about half-way through the line inside the building, as you go around this right-turn, there is this special glass on the right that has parts of it that change rapidly from clear to translucent. I think C3PO is working behind it. This is one of the details they added to the attraction in the past few years.

Anyway, I always wondered how they did that. The entire piece of glass doesn't change at once, only a few squares of it at a time. The piece of glass appears to be one single solid piece (maybe 8 feet tall by 6 feet wide or so if I remember correctly) with no wire leads going to the squares visable (some of the squares are in the middle). The squares don't change to black, but to white translucent, looking much like frosted glass.

I have asked several imagineers about it, but as usual the answer was simply 'it's just magic' followed by 'I can't disclose any of our secrets'.

Has anyone else noticed this piece of glass, and better yet does anyone know how they did it?!

--SONET

Re:Speaking of which... a mystory

[Hal-9001]

My guess is that it's a liquid crystal panel. It might also be possible to make a electrochromic material that turns light and opaque as well as dark and opaque.

Re:Transparent aluminum - correction

[tartley]

I think you mean an array of void *.
--
There are 10 kinds of people in the world, those who think in binary, and those who don't.

Re:Blend of two transp. materials is not always .

[mamba-mamba]

Yeah.

And as the article says, concrete is normally re-inforced when it is used for any type of load-bearing structure. So technically it's sort of a composite material. A bit like fiberglass-epoxy composite. And, despite the fact that both glass and epoxy are transparent, any reasonably thick layer of fiberglass/epoxy is merely translucent. (Unless you paint it or put dye in the epoxy, of course, in which case it is opaque.) I think this proves your point rather well.

If they want transparency they will have to find some way to adjust the index of refraction of the cement (or glue, as they call it), aggregate, and rebar to all match closely, and they will need a reasonably smooth surface finish as well.

Frankly, I think using glass (or clear plastic) aggregate, epoxy and steel rebar would make for a pretty cool-looking structure even if it weren't remotely transparent. The building cost would be out of control, however, and UV radiation is not good for epoxy. Epoxy exposed to sunlight turns yellow pretty quick, and is significantly weakened, at least near the surface.

MM
--

Super Bowl, Superchurches

[Mittermeyer]

I see this being used in stadium domes as a cheap way to light the dome without paying the electricity. Depending on it's insulation, location and gametime it may or may not save money on heating/cooling too over normal domed stadiums.

Superchurches (the 7000+ seating variety) could also use this, which might make for requests for stained glass varieties of Dr. Price's new material (whatever it is).

Microsoft developing transparent concrete??

[LuckyPhil]

It's a conspiracy I tell you!!!

Microsoft have been developing transparent concrete for a while now..

fine aggregate = Windows CE
course aggregate = Windows ME
binding agent = Windows NT

Mix them all together and you get

Microsoft CE-ME-NT

Environmental Impact Should be Foremost Concern

[mr_don't]

He is also keen for transparent concrete to be an environmentally friendly material that can be recycled--though that, too, seems a tall order.

Even though it is a tall order, it should be the most important order...!

I'd rather have sustainability than transparent buildings!

Transparent Aluminium - The Real Reason

[dupper]

Before I get started, I stress that this is NOT OFFTOPIC, as it addresses a ST:IV nit that's been posted many times to this discussion.
Okay, here it is: Scotty presumably chose to use transparent aluminium rather than steel or some other substance because he had no way to obtain any other substance. He had to give away something significant, which he had access to in either his knowlege or the Bounty (the B'rel in the movie), in order to gain access to to a material. Rather than give away the secret for, say, Duranium, which would have enabled humans to build things so strong that they would change humanity's future drastically (e.g. allowing inpenetrable (by the weapons of the day) armour, or disaster (think terrorism) -proof buildings, etc.), he chose to do the least possible timeline damage as possible by giving away a trivial secret, only useful for aesthetics. Thus, transparent aluminium was the correct choice.

Oh, it has to be said! Obligatory references:

[Magius_AR]

We don't have to invent it, we just have to wait for someone to return to the past and show us how its made.
After all, how do you know *insert arbitrary name here* didn't invent the bloody thing?

*while holding mouse to mouth*
Computer? Hello, computer?

Magius_AR

glass and Mr. Wizard

[_avs_007]

I remember on Mr. Wizards World a long time ago, he said glass actually isn't a solid but a VERY viscous liquid. He even showed this old pane of glass from a cathedral, and the bottom had a noticable buldge. He said it was because over the 300 years that this glass was standing up, the glass slowly flowed down....

Re:glass and Mr. Wizard

[Nicolas MONNET]

That's just untrue, glass IS a solid, which happens to have some property of liquids. Proof? It can be melted!

Now there are materials that are almost impossible to classify, I don't remember the name, but it looks like clay, but is hard when you touch it, and breaks when you try to fold it. However, if you leave for a couple hours on a table, it will flow like goo.

Re:glass and Mr. Wizard

[pennsol]

it's called water and cornstarch..take 1 handfull of cornstarh add abit of water and nead it till it feels like dough..then stop moving it..it turns into a runny goo..pretty cool

Re:glass and Mr. Wizard

[_avs_007]

Well, I just spent some time researching it... Like I said, it was on Mr. Wizards World like 15 years ago....

Anyways, nobody seems to have a clear answer either way.... So who cares, I guess...

And in regards to your answer... That doesn't prove anything... Did you really melt it? There is no first order phase transition.... Besides... Take a high viscosity oil, like a 50wt oil. It is very thick, yet if you heat it up, it will get thinner. You could apply the same to glass...

Also, on this planet... Look at carbon dioxide... namely dry ice... That is a solid by every definition of a solid. Yet you cannot melt it to form a liquid. Since you cannot "melt" it, does that mean it is not really a solid? No...

As for the "goo" you are talking about. You mean corn starch and water right? Well, technically speaking that substance is still classified as a liquid. Also it is not hard when you touch it... If you slowly put your finger in it, it behaves like a liquid, but if you were to quickly touch it, or pound it, it behaves like a solid...

Would help the crime rate.

[WyldOne]

I can see it now...
Burgler1: Oh man this place has barred doors.
Burgler2: Just brek a window man.
Burgler1: *SMAACK* *SMACK* *SMACK*.. Hey! what the...I bent my crow bar!
Burglur2: Here let me try...moron. *SMAACK* *SMACK* *SMACK*.. Hey! what the...I beusted my fist
Burgler1: HA HA HA HA, Whos the mon now?
Burgler2: It aint worth it lets go next door.

Could be a fire problem thou.
Builder: Um... emergency exits?

Bigger reason why not transparent

[WyldOne]

Have you ever looked at concrete? Its filled with lots of air pockets. It's like the fractal sphere packing problem.

The problem is agravated by the material itself. As concrete cures it generates gas. most of it never reaches the surface to disapate. Therefore; causing voids to apear in the final material. Vibrating the concrete before it's fully cured helps but is never perfect.

Even if you used rosin as the glue and glas beads as the aggregate, you would still have bubbles. As any POVRAY user would tell you you can never get a perfect merge like that in real life.

Who cares? Transparent tanks are not a plot point

[NanoGator]

I don't think "Why was the tank transparent??" is on the same level as "How can a Macintosh computer talk to an alien computer, give it a virus, and disrupt the defensive shields on every single alien ship attacking?"

The truth is, I don't think "why does this need to be transparent?" was much of a plot point. They needed materials to build a tank, and plexi-glass suited their needs. It really doesn't need to be more complex than that. I don't think anybody was on the edge of their seats going "Why do they need plexi-glass!?!?!? Yeesh, what a crappy movie.".

This type of detail sounds more like you were fishing for an inconsistency in the movie so you could make yourself look more observant. It seems like everybody nowadays is looking for flaws in movies so they can appear smarter to everybody else. The problem with doing this is that you ruin the movie for youself. What's embarrasing is that both Star Trek and Star Wars fans do this alot.

One of my favorite examples of these ludicrous debates is "Turbo Lasers aren't lasers! They don't act like lasers, they can't be lasers!" I actually watched a forum grow out of control over this topic about Star Wars. People got upset! There was name calling and everything. This type of behaviour makes people say "Damn dudes, get a life!!". This makes me afraid to admit I like any of these shows/movies for fear that I might get grouped along with these people.

It's fun to have discussions about it, but to get heated about it is absurd.

Anyway, it's not my intention to flame you, btempleton. I just thought it'd be right of me to bring to your attention the way I interpreted your post.

Re:Who cares? Transparent tanks are a plot point

[btempleton]

The tanks, as I said, are not the plot point. In fact they have no real need for them.

The plot point is the time they spend hunting around for money and other means to get the tanks. Kirk sells his glasses and Scott hands over a major new piece of chemistry.

That's the part that was bogus. They didn't need transparent tanks. And frankly, I'm amazed the Klingons didn't have a waterproof hold anyway, or one that could be made waterproof enough for the trip. But if they didn't, they would have affected the past far less by just transporting plates from a yard, stealing though it would be. They just wanted to have a cute scene where Scott tries to talk to a mouse.

(And yet somehow is able to then handle a molecular modelling package like a master.)

Should be fairly easy.

[Mr. Piccolo]

All you need is clear large aggregate, clear small aggregate, and adhesive, all with the same index *(&#*&$^*00==0== NO CARRIER

Re:Warning

[Spock the Baptist]

Methinks -- that he confused moral decay with exponential decay...

If it saves just one life...

[Bob_Robertson]

If it saves just one life, it's worth it!

Only an idiot would argue against such a common sense safety measure.

Do it for the children.

Re:Who cares? Transparent tanks are a plot point

[btempleton]

Indeed. But one of the reasons people read science fiction, and go to SF movies, is because they like seeing an interesting and coherent imagined world presented. And sure, Star Trek could do a far better job at it, but back in 1967, it was actually way ahead of most of the other media SF, so it got its fans.

This is not just SF. With a mystery, the clues and resolution need to be consistent or the viewers will be annoyed. You can't tell them it's just a story.

So it is just a movie, but viewers want it to be a better movie, so when it does something stupid, something not just outside of the rules of its own imagined world but outside the rules of reason, expect people to be annoyed, even if it's just a movie.

Aye Scotty...

[Emperor BMA]

'tis'nt long 'til we'll be beamin' up whales into our starships!

a great idea..

[pennsol]

i live in a place that where part of the year we need to put up boards or shutters for hurricanes.. if all the windows were concrete like the rest of the structure it sure would save alot on things like insurance(i.e. no windows to break for the 150 mph+ winds) and would be awful cool to accually see outside during a storm..since i've been through 6 in the past 5 years spending 20+ hrs in a very dark room is not the funnest thing i've ever done ..but hey i can go to the beach any day of the year....

Re:Fire resistant? Or toxic smoke as it burns?

[Derek Pomery]

Site is short on information, but it appears this is a mineral/polymer composite, and unfortunately, one that isn't transparent.

Don't know what minerals they are using. Wonder if they could use silicates...

For that matter, the transparent columns, any reason the aggregates couldn't be glass? I think glass would even be cheaper to produce in mass quantities.

What About Rebars?

[SlipJig]

If (and it's a big if) they can get this stuff to a workable state, you still have other things to deal with. For example, concrete has little appreciable tensile strength and elasticity, which is why engineers place steel reinforcing bars (rebars) all through the concrete. Seeing the rebars kills the illusion of transparency.

This stuff would need to expand/contract with temperature at a similar rate to the steel, otherwise you run into problems. You could pre- or post-tension the structure with steel cables run through sleeves in the concrete, but the sleeves also need the same thermal expansion/contraction ratio.

Here in the U.S. concrete is most often used as a structural material anyway, not as a cladding system (though these exist). People don't usually make walls out of it; for these purposes, if you want translucency or transparency, it seems far easier to use any of the myriad varieties of glass block, assuming you don't need a whole lot of structural strength.

Disclaimer: I studied architecture for 4 years and my wife is an architect, but I've been out of the loop for 10 years or so. Civil engineers or architects, please correct me if I'm wrong about any of this.