Sprague's law on material properties

"Whenever you first hear about a new material, that's the best properties you'll ever have." Paired with Williams's corollary on cost.

One of the problems with this edge-defined film growth — I was out there at that lab, and they have nice machines and it works, but it's really slow. When you're pulling something that thin and that light, you don't make very many pounds per hour. This is where you get to Sprague's law: whenever you first hear about a new material, that's the best properties you'll ever have. And Williams's corollary: whenever you first hear about the cost of a new material, that's the lowest cost it'll ever have.

Bob Sprague (GE Aircraft Engines, 1970s): "When you first hear about the properties of a new material, write it down — those are the best properties the material will ever have."

Thinking statistically, it's going to be weak. A chain is as strong as its weakest link. If I go to higher temperatures, it becomes weaker with more vacancies. If I have lots of nanotubes — yes, ten nanotubes are probably ten times stronger than one nanotube, but that doesn't mean it'll be 3 million PSI, because it's still per unit area. And if I still have a flaw — there was a guy, head of materials at GE aircraft engines in Cincinnati, Bob Sprague back in the 1970s. He was the one who said: when you first hear about the properties of a new material, write it down — those are the best properties the material will ever have. And there's the Jim Williams corollary. Jim Williams was Dean at Ohio State and department head at Carnegie Mellon, and is an expert on titanium. He became head of materials at GE aircraft engines in the 1990s, after Sprague. Jim's corollary: whenever you first hear about the cost of a new material, write it down, because that's the lowest cost the material will ever have.

Which brings me back to another Robert Sprague quote — I didn't bring the overhead for it. Sprague's law: anything with anything tensile, in compression — the biggest use of any composite in the world is Portland cement, mortar and rock. That's a composite material, but you design it for compression, and you put steel rod in when it has to be in tension. So I'm not knocking composites completely. I'm just saying when people talk about high-performance composites, they're often not worrying about the cost. That's where you get Jim Williams' corollary: whenever you first hear about the cost of a new material, write it down, because that's the lowest cost you'll ever have.

Robert Sprague, head of materials at GE Cincinnati: "whenever you first hear about a new material, write it down, because those are the best properties that material will ever have."

Materials and new materials, or whatever you read in the MIT news and see on the screens at MIT — most of this is oversold. Ninety-eight percent of it is a sales job, and it's not really quite that great. There's a quote that I like. There was a guy at General Electric in Cincinnati where they make aircraft engines, head of materials, name was Robert Sprague. And Robert Sprague had a quote: whenever you first hear about a new material, write it down, because those are the best properties that material will ever have. And then there's Jim Williams' corollary. Jim Williams was a titanium metallurgist who became department head at Carnegie Mellon and Dean at Ohio State, and then he replaced Bob Sprague at General Electric. Jim Williams says his corollary to Bob Sprague's quote is: whenever you first hear about the cost of a new material, write it down, because that's the lowest price the material will ever have.

Bob Sprague (head of materials, GE aircraft engines, Cincinnati): first reported properties of a new material are the best it will ever have. Corollary (Jim Williams): first price is the lowest it will ever have.

That brings up this slide. I've quoted this before, from Bob Sprague, who was head of materials for General Electric aircraft engines in Cincinnati for many years: whenever you first hear about the properties of a new material, write it down — those are the best properties the material will ever have. This is actually Jim Williams' slide; he gave this to me once after he heard me quote Bob Sprague. He calls it Sprague's first law: whenever you first hear about the material, write it down. His corollary: whenever you first hear about the price of a new material, write it down, and that's the lowest price it will ever have. Materials scientists tend to oversell their materials big time, because they want you to believe they just discovered the Rosetta Stone of materials and everything will be made out of their material next year. Doesn't quite work that way.