Fusion a suicidal power source?

[Janus]

This is exactly what I mean.
Janus, what was your final number, you did not make it explicitly clear.

Rerunning the numbers through a spreadsheet, with the following data;

World yearly energy usage: 404 quads. (1 quad = 1 x 10^15 BTU or 1.054 x 10^18 joules.

volume of the oceans : 317,000,000 cubic miles.

percentage of mass converted to energy by hydrogen fusion : 0.4%

The fraction of the mass of water due to hydrogen: 1/9

World energy usage: 404 * 1.054e+18 = 4.258E+20 J

Amount of water needed to provide this much energy via fusion:

4.258E+20 J/ (3e8m/s)² * 9/ .004 = 10,645,400 kg.

(compare this to the 4 billion tons of coal alone the world burns in one year. )

Oceans' volume


317,000,000 * 4.09 = 1296530000 km³
* 1000³ = 1.297E+18 m³
* 1000 = 1.297E+21 Liters

converted to kg:

= 1.297E+21 kg.

1.297E+21 kg/10,645,400 kg = 8.211E-15
or
0.0000000000008211% of the world's oceans used a year.

 

[Pengwuino]

Omg we can only survive for 1.22 trillion years on fusion :(

 

[Bjørn Bæverfjord]

I am not sure where you got that number from, I think it is off by orders of magnitude.

That was the original number that you accepted, I just tried to point out that you were happy to choose suicide instead of any of several sustainable paths.

The corrected number puts everything in a different light as it does not point to a rapid disaster.

 

[MonstersFromTheId]

Janus;
Thanks for the numbers, makes it easier to get a grip.
What was worrying me about the original 1/1000,000ths of the planet's water supply per year was that relatively tiny changes in the amount of over all water could possibly have signifigant effects on things like weather.
1/10,000th of all water gone in a century seemed a bit of a cause for concern seeing as how:
1) Once the water is gone it ain't NEVER comin back. This isn't like polluting water, it's out and out destroying it permanently.
2) As we're learning now, once you're addicted to a particular power source it can be a very difficult habit to kick.
3) Increases in energy useage don't look likely to flatline anytime soon, so basing calculations on *current* needs is certainly debatable.

All of which, for me at least added up to an "EEEK!"

But... "0.0000000000008211% of the world's oceans used a year." is one heck of a lot less scary number. With a rate of loss that low, a deadly attack by five headed space aliens would be a lot more likely to keep me up nights.

 

[Pengwuino]

Yah and come on, in a trillino years (the inverse of that number), we'll have figured something out lol.

 

[Danger]

Yah and come on, in a trillino years (the inverse of that number), we'll have figured something out lol.

I can probably arrange to be elsewhere by then.

 

[Janus]

Yah and come on, in a trillino years (the inverse of that number), we'll have figured something out lol.

Don't get too cocky, after all, we need deuterium, which makes up only 0.02% of naturally occurring hydrogen. That'll drop us down to 200 million years of fuel.

 

[Danger]

That'll drop us down to 200 million years of fuel.

So you're half-way through your theoretical lifespan?



edit: Oh crap... cancel that last remark. I just looked at your profile. You're younger than me .

 

[MR. P]

we already have a fusion reactor! It's so powerful it has to be 93,000,000 mi away...the reason we have so much water here is for heat transfer...being a refugee from the nuc industry has taught me that if your solution is complicated then some man or men made it! Nature is much more elegant ...the energy contained in the water vapor surrounding the planet is ubiquitous and replenished continulualy 24-7 if we spent more of our gray matter trying to make simple machines to transform this energy reservoir into the forms we currently use ie mechanical electrical etc the value of that simple atom would become much more manifest...just an opinion in favor 0f monstersfromtheid's musings

frank MR. P

 

[mios76]

Jupiter and Saturn consist of hydrogen. I believe it is not going to be a problem to extract it even from those places in the year 3000.
An interesting question is: how much energy we get by fusing those planets?

 

[Danger]

how much energy we get by fusing those planets?

Jupiter is considered by many to be a 'proto-sun'; ie a planet who is just a bit too small for its gravity to compress it to the point of fusion ignition. If you could manage to smack it and Saturn together, we'd have 2 suns in our solar system. I don't think that they make a SPF formula strong enough to handle that.

 

[EvilEyeGuy]

Is no one taking into account that world energy consumption annually increases?
Because of this by the time fusion is adopted, wouldn't energy usage be at least some what higher, then accounting for yearly increase I believe the number would be somewhat smaller then 50 million.
(I do not actually know the percentage of the increase, might be important I don't know *sarcasm*)

 

[russ_watters]

Considering that the world has only been generating electricity for 150 years, it is tough to make projections out to 50 million years...

Besides, we aught to fix the immediat problems immediately and save the ones that won't affect us for millions of years for later.

 

[bassplayer142]

If we have Fusion power we could easily establish a base on the moon. And then easily get Hydrogen from compounds on the moon. It would take a lot of mass loss on the moon to actual see real results on earth. I'm excited for Fusion though!

 

[vanesch]

Don't get too cocky, after all, we need deuterium, which makes up only 0.02% of naturally occurring hydrogen. That'll drop us down to 200 million years of fuel.

For the moment, we need deuterium from water. Nevertheless, with enough neutron irradiation, we can turn light hydrogen into deuterium (the fusion equivalent of a fission breeder reactor). So enough water in the blanket of a fusion reactor will turn it into deuterium...

 

[EvilEyeGuy]

If we have Fusion power we could easily establish a base on the moon. And then easily get Hydrogen from compounds on the moon. It would take a lot of mass loss on the moon to actual see real results on earth. I'm excited for Fusion though!

From where, the Moon's oceans? I'm pretty sure that theory is a bit in-accurate.

 

[keinve]

other elements can be used. the elements you have stated are simply the eaisest.