Re: USA urges scientists to block out sun

On Feb 3, 3:45 pm, Ian Stirling <r...@xxxxxxxxxxxxxxxxx> wrote:
Willie.Moo...@xxxxxxxxx wrote:
On Feb 2, 2:31 pm, Ian Stirling <r...@xxxxxxxxxxxxxxxxx> wrote:
steve <stephen.colbou...@xxxxxxxxxxxxxxx> wrote:
Well the good news for you is that at one tonne per sqkm = 1 gram per
square metre.

That should make your space shield much more practical- Hide quoted text -

- Show quoted text -

Doh! You're right. I slipped a digit and a factor of 1,000! .

The plastics from which GBO is made are 1.2 metric tons per cubic
meter, so 1 gram per square meter is a thickness of 0.83 mm - that's

No, it's not.
There are a thousand litres in a cubic meter.
A thickness of a milimeter with an area of 1m has a volume of one litre,
which has a weight of one kilogram.



830 um - far larger than I was thinking. - Two layers 100 um thick -
one transparent, the other refletive, filled with a veyr low pressure
gas - to create a pressure stabilized structure. At 1/2 gram per sq
meter. A 3 km diameter mirror would then weigh 7 tonnes. 70 tons
would be 16.5 km in diameter. 660 tons 29.1 km diameter. 191,440 of
the larger mirrors would be needed to cover the entire surface of the
Earth. 1,915 mirrors would intercept 1% of the sunlight. Over a 5
year period that's 1 launch per day. With a 30 day turn around,
that's a fleet of 30 of the more massive vechicles.

At $6 billion each that's $180 billion - a far far smaller program.

The system could still beam 300 TW to Earth, which could pay for it
all.- Hide quoted text -

- Show quoted text -

Yes, I listened to you and was confused! lol. So, is your original
point correct or not?

<sigh>

Well, lets figure it out - haha..

1000 gram = 1 kg
1000 kg = 1 tonne

1,000,000 grams = 1 tonnes

1 mm = 1/1,000 meter
1 um = 1/1,000 mm
1,000,000 um = 1 m

At 1.2 gams per ml or 1.2 tonnes per cubic meter for the types of
plastics used for GBO then layers 1 square meter in are are;

830 nm = 1 gram per sq meter
830 um = 1 kg per sq meter

haha.. SO, MY ORIGINAL NUMBERS ARE THE CORRECT ONE!

And your original point in error.

To obtain the sorts of masses you were putting out there, and which I
wrongly agreed to, by assuming I missed 3 digits, we'd have to use
nano-scale structures like butterfly wings - which i originally said.
It may be possible to attain these weights, but we won't be able to
use gases to create the structures. We'd have to use electet type
charges between the transparent and reflective sheets.


Sheez


haha..

.