Dave Head's "Space Shield" DEBUNKED

Dave Head,

I'd like to present some numbers relating directly to the feasibility
of your space shield global warming "cure". These calculations assume
impossibly light materials that most likely do not exist. A real shield
would require much heavier and stronger materials to withstand all the
forces acting on it including micrometeorites.

If we were to build a 2.5 million km^2 area space shield (see my
previous posts), with a thickness of, say 100 cm (yes, that thin!), and
material at a density of 10 kg/m^3 (yes, that light!), we have a volume
of (0.1 m) * (2,500,000 km^2 x 1,000,000 m^2/km^2) = 250,000,000,000
m^3. Total mass: 2,500,000,000,000 kg. Launch cost: $22,000/kg [1]
giving a total of $55,000,000,000,000,000! Holy crap!

Since this is obviously an impossibly light shield, the actual price is
much higher. At a more reasonable but still very low 100 kg/m^3 the
cost of the panel jumps to 550 quadrillion dollars. At the density of
iron, 8000 kg/m^3 the cost becomes a staggering 44 *Quint*illion USD!!!
The total gross domestic product of the entire planet is only around
$55 *tr*illion [2], a thousandth of the minimal price and 1/800,000th
the price with iron. There is simply not enough money in the world to
do the job. Not by a long shot.

Ie. your idea simply cannot work. Not with present spacelaunch
technology and economy, that's for sure, and I don't see the technology
being developed any time soon without massive spending and even then I
don't know if it would be in time.

Those are the hard numbers. Do with it what you want.

SOURCES:

[1] http://www.msfc.nasa.gov/news/news/r...00/00-237.html

[2] http://en.wikipedia.org/wiki/Orders_...tude_(currency)

mike3 wrote:
> Dave Head,
>
> I'd like to present some numbers relating directly to the feasibility
> of your space shield global warming "cure". These calculations assume
> impossibly light materials that most likely do not exist. A real shield
> would require much heavier and stronger materials to withstand all the
> forces acting on it including micrometeorites.
>
> If we were to build a 2.5 million km^2 area space shield (see my
> previous posts), with a thickness of, say 100 cm (yes, that thin!), and
> material at a density of 10 kg/m^3 (yes, that light!), we have a volume
> of (0.1 m) * (2,500,000 km^2 x 1,000,000 m^2/km^2) = 250,000,000,000
> m^3. Total mass: 2,500,000,000,000 kg. Launch cost: $22,000/kg [1]
> giving a total of $55,000,000,000,000,000! Holy crap!
>
> Since this is obviously an impossibly light shield, the actual price is
> much higher. At a more reasonable but still very low 100 kg/m^3 the
> cost of the panel jumps to 550 quadrillion dollars. At the density of
> iron, 8000 kg/m^3 the cost becomes a staggering 44 *Quint*illion USD!!!
> The total gross domestic product of the entire planet is only around
> $55 *tr*illion [2], a thousandth of the minimal price and 1/800,000th
> the price with iron. There is simply not enough money in the world to
> do the job. Not by a long shot.
>
> Ie. your idea simply cannot work. Not with present spacelaunch
> technology and economy, that's for sure, and I don't see the technology
> being developed any time soon without massive spending and even then I
> don't know if it would be in time.
>
> Those are the hard numbers. Do with it what you want.
>
> SOURCES:
>
> [1] http://www.msfc.nasa.gov/news/news/r...00/00-237.html
>
> [2] http://en.wikipedia.org/wiki/Orders_...tude_(currency)

You needed wiki to tell you that many zeroes made a quadrillion?

Lewzer.

Dave

Tell it to these guys:

http://dsc.discovery.com/news/2006/1...061107 105030

and

https://ssl.catalog.com/~ultimax.com...s/2001_3a.html

There's lotsa hits on google for 'global warming solar shield'

Dave Head

On 4 Jan 2007 22:40:19 -0800, "mike3" > wrote:

>Dave Head,
>
>I'd like to present some numbers relating directly to the feasibility
>of your space shield global warming "cure". These calculations assume
>impossibly light materials that most likely do not exist. A real shield
>would require much heavier and stronger materials to withstand all the
>forces acting on it including micrometeorites.
>
>If we were to build a 2.5 million km^2 area space shield (see my
>previous posts), with a thickness of, say 100 cm (yes, that thin!), and
>material at a density of 10 kg/m^3 (yes, that light!), we have a volume
>of (0.1 m) * (2,500,000 km^2 x 1,000,000 m^2/km^2) = 250,000,000,000
>m^3. Total mass: 2,500,000,000,000 kg. Launch cost: $22,000/kg [1]
>giving a total of $55,000,000,000,000,000! Holy crap!
>
>Since this is obviously an impossibly light shield, the actual price is
>much higher. At a more reasonable but still very low 100 kg/m^3 the
>cost of the panel jumps to 550 quadrillion dollars. At the density of
>iron, 8000 kg/m^3 the cost becomes a staggering 44 *Quint*illion USD!!!
>The total gross domestic product of the entire planet is only around
>$55 *tr*illion [2], a thousandth of the minimal price and 1/800,000th
>the price with iron. There is simply not enough money in the world to
>do the job. Not by a long shot.
>
>Ie. your idea simply cannot work. Not with present spacelaunch
>technology and economy, that's for sure, and I don't see the technology
>being developed any time soon without massive spending and even then I
>don't know if it would be in time.
>
>Those are the hard numbers. Do with it what you want.
>
>SOURCES:
>
>[1] http://www.msfc.nasa.gov/news/news/r...00/00-237.html
>
>[2] http://en.wikipedia.org/wiki/Orders_...tude_(currency)

On 4 Jan 2007 22:40:19 -0800, "mike3" > wrote:

>Dave Head,
>
>I'd like to present some numbers relating directly to the feasibility
>of your space shield global warming "cure".

It's idiocy.

>These calculations assume
>impossibly light materials that most likely do not exist. A real shield
>would require much heavier and stronger materials to withstand all the
>forces acting on it including micrometeorites.
>
>If we were to build a 2.5 million km^2 area space shield (see my
>previous posts), with a thickness of, say 100 cm (yes, that thin!), and
>material at a density of 10 kg/m^3 (yes, that light!), we have a volume
>of (0.1 m) * (2,500,000 km^2 x 1,000,000 m^2/km^2) = 250,000,000,000
>m^3. Total mass: 2,500,000,000,000 kg. Launch cost: $22,000/kg [1]
>giving a total of $55,000,000,000,000,000! Holy crap!
>

55 quadrillion? Interesting. I suppose he plans to have the
federal reserve just print the money?

>Since this is obviously an impossibly light shield, the actual price is
>much higher. At a more reasonable but still very low 100 kg/m^3 the
>cost of the panel jumps to 550 quadrillion dollars. At the density of
>iron, 8000 kg/m^3 the cost becomes a staggering 44 *Quint*illion USD!!!
>The total gross domestic product of the entire planet is only around
>$55 *tr*illion [2], a thousandth of the minimal price and 1/800,000th
>the price with iron. There is simply not enough money in the world to
>do the job. Not by a long shot.
>
>Ie. your idea simply cannot work. Not with present spacelaunch
>technology and economy, that's for sure, and I don't see the technology
>being developed any time soon without massive spending and even then I
>don't know if it would be in time.
>
>Those are the hard numbers. Do with it what you want.
>
>SOURCES:
>
>[1] http://www.msfc.nasa.gov/news/news/r...00/00-237.html
>
>[2] http://en.wikipedia.org/wiki/Orders_...tude_(currency)

Dave Head wrote:

> Tell it to these guys:
>
> http://dsc.discovery.com/news/2006/1...061107 105030
>

You consider the Discovery Channel to be an authoritative source ?


> and
>
> https://ssl.catalog.com/~ultimax.com...s/2001_3a.html
>
> There's lotsa hits on google for 'global warming solar shield'

Google hits don't really mean very much.

Graham

Scotius wrote:

> "mike3" > wrote:
>
> >Dave Head,
> >
> >I'd like to present some numbers relating directly to the feasibility
> >of your space shield global warming "cure".
>
> It's idiocy.

It certainly is.


> >These calculations assume
> >impossibly light materials that most likely do not exist. A real shield
> >would require much heavier and stronger materials to withstand all the
> >forces acting on it including micrometeorites.
> >
> >If we were to build a 2.5 million km^2 area space shield (see my
> >previous posts), with a thickness of, say 100 cm (yes, that thin!), and
> >material at a density of 10 kg/m^3 (yes, that light!), we have a volume
> >of (0.1 m) * (2,500,000 km^2 x 1,000,000 m^2/km^2) = 250,000,000,000
> >m^3. Total mass: 2,500,000,000,000 kg. Launch cost: $22,000/kg [1]
> >giving a total of $55,000,000,000,000,000! Holy crap!
> >
>
> 55 quadrillion? Interesting. I suppose he plans to have the
> federal reserve just print the money?

LOL.

That's only about 5,000 years worth of the entire US GDP.

Those armchair astronauts who popularise this nonsense don't have to worry
themselves about such trifles though. Nor the feasibility of 'energy beams'
either come to that.

Graham

On Fri, 05 Jan 2007 17:57:26 +0000, Eeyore
> wrote:

>
>
>Dave Head wrote:
>
>> Tell it to these guys:
>>
>> http://dsc.discovery.com/news/2006/1...061107 105030
>>
>
>You consider the Discovery Channel to be an authoritative source ?

Do you like the Astronomical Society fo Endinburgh any better?

http://www.astronomyedinburgh.org/pu...48/page3.shtml

>
>
>> and
>>
>> https://ssl.catalog.com/~ultimax.com...s/2001_3a.html
>>
>> There's lotsa hits on google for 'global warming solar shield'
>
>Google hits don't really mean very much.
>
>Graham

On Fri, 05 Jan 2007 17:57:26 +0000, Eeyore
> wrote:

>
>
>Dave Head wrote:
>
>> Tell it to these guys:
>>
>> http://dsc.discovery.com/news/2006/1...061107 105030
>>
>
>You consider the Discovery Channel to be an authoritative source ?

And here's some NASA thinkers on the subject:

http://forum.nasaspaceflight.com/for...ts=200&start=1

>> and
>>
>> https://ssl.catalog.com/~ultimax.com...s/2001_3a.html
>>
>> There's lotsa hits on google for 'global warming solar shield'
>
>Google hits don't really mean very much.
>
>Graham

Dave Head wrote:

> Eeyore > wrote:
> >Dave Head wrote:
> >
> >> Tell it to these guys:
> >> http://dsc.discovery.com/news/2006/1...061107 105030
> >
> >You consider the Discovery Channel to be an authoritative source ?
>
> Do you like the Astronomical Society fo Endinburgh any better?
>
> http://www.astronomyedinburgh.org/pu...48/page3.shtml

I don't doubt it would work.

They don't however address the issues of practicality or cost.

Graham

Dave Head wrote:

> Eeyore > wrote:
> >Dave Head wrote:
> >
> >> Tell it to these guys:
> >> http://dsc.discovery.com/news/2006/1...061107 105030
> >
> >You consider the Discovery Channel to be an authoritative source ?
>
> And here's some NASA thinkers on the subject:
>
> http://forum.nasaspaceflight.com/for...ts=200&start=1

No sign of taking the practicalities into consideration again.

Apparently one guy says the reflectors will be made in a factory on the *MOON* ! Get real Dave !

It's pure poppycock.

Graham