EROEI -- still not a reason to believe in Limits to Growth (was The Limits)

--- In spacesettlers@yahoogroups.com, sraj wrote:
> such issues as EROEI

Please tell us about it. How much of the 200 trillion tonnes (32.4 billion years' worth) of fission fuel in the earth's crust is above-unity?

Answer: 100%
http://nuclearinfo.net/Nuclearpower/UraniuamDistribution

> global warming.

What be the relevance of that given that it can't be stopped, whatever costs it might have seem to be virtually zero, and that it seems to be helping (by, for example, melting sea ice, thereby removing a hindrance to sea traffic)?

> getting the first 1000 people out into space.

Do you think 450+ mm silicon wafers shouldn't be fabricated in micro-g environments?:
http://www.hlcas.com/en/html/1345.htm

Notice the thickness keeps growing:

1 inch.
2 inch (50.8 mm). Thickness 275 m.
3 inch (76.2 mm). Thickness 375 m.
4 inch (100 mm). Thickness 525 m.
5 inch (127 mm) or 125 mm (4.9 inch). Thickness 625 m.
150 mm (5.9 inch, usually referred to as "6 inch"). Thickness 675 m.
200 mm (7.9 inch, usually referred to as "8 inch"). Thickness 725 m.
300 mm (11.8 inch, usually referred to as "12 inch" or "Pizza size" wafer). Thickness 775 m.
450 mm ("18 inch"). Thickness 925 m (expected).

Can you guess why?: "Wafers grown using materials other than silicon are generally not available in sizes over 100 mm, and will have different thicknesses than a silicon wafer of the same diameter. Wafer thickness is determined by the mechanical strength of the material used; the wafer must be thick enough to support its own weight without cracking during handling.

The larger the wafer, the less space on the edges as a percentage of total space. This means, less of the wafer is un-etched, and in theory should have higher productivity. This is the basis of shifting to larger and larger wafer sizes."

So, the industry wants larger wafers, but the only way to accomplish that is by making the wafers thicker -- which is inefficient -- because "the wafer must be thick enough to support its own weight".

Hmmm. I wonder what could be a solution to that? Hmmm.

The current move to 450 mm is being funded by $100 billion from an industry consortium, by the way. I wonder how much they'd be willing to pay to develop a method to produce 1-meter wafers at same thickness that was used for 2-inch wafers? A trillion?