Tag Archives: engineering

Epic engineering: It still lives

hooverThis Arizona Republic item put me in mind of William Gibson’s early story “The Gernsback Continuum,” a rumination on the golden age of mega-construction. I saw this engineering marvel on a recent drive to Vegas (bookie, debt, showgirl–long story) and it’s an awe-inspiring sight.

A quarter-mile downstream from Hoover Dam, two fingers of concrete stretch toward each other from sheer cliffs, suspended nearly 900 feet above the Colorado River.

In a month, the fingers will meet, an 80-foot gap will close and the longest concrete arch in the Western Hemisphere will be complete.

The union will mark a major milestone in the nine-year construction of the Hoover Dam bypass bridge, scheduled to open in late 2010.

But even incomplete, the overpass, officially known as the Mike O’Callaghan-Pat Tillman Memorial Bridge, evokes a sense of wonder. Towering columns perch on naked rock. The arch is held by tendons of steel cable…

The $114 million bridge project has been a challenge. Accidents delayed it by two years and claimed one life, as workers battled intense heat, dangerously high winds and perilous heights…

Work crews had to build foundations for the arches midway up two sheer cliff faces, hundreds of feet above the river.

Temperatures as high as 120 degrees strain workers and heat up wet concrete. Crews use liquid nitrogen to keep the concrete cool so blocks don’t develop fatal cracks.

[Nevada side of the Mike O’Callaghan-Pat Tillman Memorial Bridge under construction at the Hoover Dam. Taken May 3, 2009 by squeaks2569]

Predicting future technologies with Eric Drexler

chipEric Drexler describes how you can apply scientific methods to assess the lower bounds of the capabilities of future technologies:

A subset of the potential capabilities of future levels of technology can be understood by means of a design process that can be described as exploratory engineering. This process resembles the first phase of standard design engineering (termed conceptual engineering, or conceptual design), but it serves a different purpose

In the early 20th century, a missing fabrication technology was the combination of engineering expertise and metalworking techniques (among others) that were required to build large aerospace vehicles. The physics of rocket propulsion, however, were well understood, and the strength and weight of large, well-made aluminum structures could be estimated with reasonable accuracy.

On the basis of exploratory engineering applied to this kind of knowledge, engineers who studied the matter were confident that orbital flight could be achieved by means of multistage chemically fueled rockets.

This was an element of Drexler’s Engines of Creation I found especially compelling: that we should base our ideas of future technologies not on what we already have, but what lies within the bounds of what is possible by physical laws as we understand them.

[image from quapan on flickr]

Science vs. engineering: Drexler waxes philosophical

engineering_scienceEric Drexler discusses the hinterland between two of the great pillars of human endeavour – science and engineering – and what they are:

Inquiry and design are seldom separate, so how can it be meaningful to call some activities “science”, and others “engineering”? I think it’s best to look beyond the mixture of inquiry and design in a project, and to consider instead its purpose. If the intended result is knowledge — a better model of what exists in the world and how it works — I think of it as science. If the intended result is a new product, process, or design methodology, I think of it as engineering.

This epistemiological discussion is with a serious goal in mind, to consider how emergent nanotechnological developments might be engineered to create products and processes we can all use:

Unlike high-energy particle physics or space science, nanotechnology springs from fields (surface science, materials science, chemistry, biology) that have no tradition of developing conceptual designs for complex systems, debating the knowns, unknowns, costs, benefits, alternative objectives, alternative solutions, and so forth, to eventually converge on objectives that coordinate the work of hundreds or thousands for a decade or more.

Without a tradition of this sort, large opportunities can go unrecognized — and in part because they are large. This will change, but I doubt that the change will be led from within.

It’s an interesting point. At what point does scientific research transfer into engineering development, and thence into entrepreneurial opportunity?

[image from jenny downing on flickr]

New resin for growing flesh

biodegradable_resinResearchers at the University of Twente have developed a biodegradable resin that can be used to create precise replicas of forms within the body around which new tissues can be grown:

The resin can be given different properties depending on where in the body it is to be used. Cells can be sown and cultured on these models, so that the tissues grown are, in fact, produced by the body itself. The new resin has been developed by Ferry Melchels and Prof. Dirk Grijpma of the UT’s Polymer Chemistry and Biomaterials research group. An article on this breakthrough will be appearing in the authoritative specialist journal, Biomaterials

The method used to recreate the specific forms is called stereolithography, the improvement in this system is that the resins have hitherto not been biodegradable. This means:

If, for example, a child has a heart valve disorder, a 3D digital image of the heart valve can be created using a CT scanner. The model in the stereolithograph can be copied exactly with the new resin. If the structure is made porous, the child’s own cells can be placed on it. This porosity also gives nutrients access to the cells. Ultimately, after the carrier structure has broken down, only the natural tissue remains.

Which is a rather wonderful development.

[from Physorg]

RepRap creates circuits

just-finishedA moment of history. The RepRap project has created circuits for the first time:

Ed and I have a final-year student – Rhys Jones – who’s working on RepRap for his MEng research project. He’s been taking the old idea of depositing metal in channels and an observation of Forrest’s and Nophead’s (that you don’t need a low-melting-point alloy because the specific heat of metals is so low that they shouldn’t melt the plastic anyway).

Also worth a look: Bruce Sterling points to Darwinian Marxism as a means of ensuring the proletariat gain possession of the means of production sans revolution.

[via the Yorkshire Ranter][image from the Reprap blog]