On 15/04/2011 16:35, Darren New wrote:
> On 4/15/2011 5:57, Invisible wrote:
>> That's kind of my point. You only need to be slightly wrong about one
>> tiny thing, and it's game over.
>
> Not really. Look up thorium salt reactors. They don't go critical, the
> wastes are not very radioactive, you can't blow them up, etc etc.
> They're much safer.

As I understand it, normal nuclear reactors are incapable of a *nuclear* 
explosion. That doesn't mean that the cooling system can't overload and 
explode. Or freak weather conditions level the building. Or somebody 
flies a passenger jet into it. Or...

>> Fires can be put out, even oil spills can be mopped up [eventually]. But
>> radiation is forever. [Or rather, "for such a huge time period that it
>> might
>> as well be forever".]
>
> Depending on the radiation, oil spills probably last longer than lots of
> kinds of radiation problems.

Uranium-235 has a halflife is 700 million years. That's /halflife/, not 
the time it takes to degrade completely, just the time for *half* of it 
to go away. 700 million years is longer than that oil has been in the 
ground. ;-)

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On 15/04/2011 16:28, Darren New wrote:
> On 4/15/2011 2:21, Invisible wrote:
>> Nuclear power works in theory. In practise, if you make even the tiniest
>> mistake, just once, everything is ruined forever.
>
> It's possible (in theory) to build a plant where such isn't the case.
> It's just that afaik nobody is doing that, because nobody has already
> done it.

I'd be rather surprised if you can build a system powered by radiation 
such that it doesn't use much radiation.

>> Harnessing the [...] sun [...]. This stuff doesn't grow on trees.
>
> Well, technically...

I said /land area/ doesn't grow on trees! :-P

>> People have tried to make cars that run on electricity rather than fossil
>> fuels. But that just means that you burn the fuel at the power plant
>> rather than in the car.
>
> The advantage is it's far more efficient to generate the power centrally
> and distribute it than it is to generate it locally.

Is it?

I mean, I'm sure a generator that runs at optimal speed 24/7 can be way 
more efficient than the clapped out old engine in your car. But doesn't 
the inherent inefficiency of distributing the power more than negate the 
advantage?

>> when they do. Yes, they're more efficient, but this really looks to me
>> like people passing a law before the technology is ready.
>
> I think the idea is more to drive up the demand in order to get people
> to invest in the research for making them better.

In that case, just ban *all* forms of lighting! That should create a 
market demand alright...

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On 4/15/2011 8:49, Invisible wrote:
> That doesn't mean that the cooling system can't overload and explode.

Right. But if you knock down a thorium salt reactor, it just gets cold. It's 
basically a big stack of pool-ball sized balls that heat up if you get a 
bunch of them close enough. So if something goes wrong and knocks down the 
wall, it cools off and you send in people in lead-lined bulldozers to scoop 
the stuff up.

 > Or somebody flies a passenger jet into it. Or...

They're designed to resist that one.

> Uranium-235 has a halflife is 700 million years.

U-235 isn't that dangerous, tho, unless you pile up enough to interact.

What it also means is that if you spill 100 pounds of U-235 somewhere, it's 
going to take 700 million years for even 50 pounds of it to have emitted 
radiation. That's a very low level of radiation.

The actual chemical properties are probably more dangerous than the 
radioactive properties if you spread it out widely enough.

 > That's /halflife/, not the
> time it takes to degrade completely, just the time for *half* of it to go
> away. 700 million years is longer than that oil has been in the ground. ;-)

Which tells you that it isn't *that* dangerous or there wouldn't be any life 
in the ground.

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."

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On Fri, 15 Apr 2011 10:21:37 +0100, Invisible wrote:

> Wind power is great. But... do you really want the whole country to go
> black every time the wind stops blowing? Similarly, solar power. You
> realise that the sun is below the horizon for hours at a time, right?
> And some days, it's just not very sunny. For either of these things to
> work, you seriously need high-efficiency power storage, so you can
> collect power when it's there, and store it for when it's not.

And most solar collection and all wind powered systems I've seen actually 
include that storage subsystem.

Jim

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On 4/15/2011 8:52, Invisible wrote:
> On 15/04/2011 16:28, Darren New wrote:
>> On 4/15/2011 2:21, Invisible wrote:
>>> Nuclear power works in theory. In practise, if you make even the tiniest
>>> mistake, just once, everything is ruined forever.
>>
>> It's possible (in theory) to build a plant where such isn't the case.
>> It's just that afaik nobody is doing that, because nobody has already
>> done it.
>
> I'd be rather surprised if you can build a system powered by radiation such
> that it doesn't use much radiation.

I didn't say that. I said a mistake doesn't leak dangerous radioactivity.

If I said "it's possible to build a car that can hit a wall at 100MPH 
without the passenger getting hurt", would you say "I'd be rather surprised 
you can build a car that won't run into walls."

> I said /land area/ doesn't grow on trees! :-P

I know. It was just amusing.

>>> People have tried to make cars that run on electricity rather than fossil
>>> fuels. But that just means that you burn the fuel at the power plant
>>> rather than in the car.
>>
>> The advantage is it's far more efficient to generate the power centrally
>> and distribute it than it is to generate it locally.
>
> Is it?

http://www.scientificamerican.com/article.cfm?id=electric-cars-cost-per-charge

How come I do your googling for you? :-)

> In that case, just ban *all* forms of lighting! That should create a market
> demand alright...

Well, banned for everyone but essential legislative services, of course.

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."

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On Fri, 15 Apr 2011 09:31:48 +0100, Invisible wrote:

>>> I think it's more controversial what to do about it.  And at least
>>> there's something that remotely *sounds* controversial about it, if
>>> you actually read the original source stuff.
>>
>> Certainly for those who believe science stands still - and that our
>> understanding hasn't changed (or should I say 'evolved'? ;) ) since
>> Darwin wrote about it.
> 
> Apparently Darwin didn't even *invent* the idea of evolution. He just
> made it popular by presenting a well-researched and compelling case for
> it, in a single large, self-contained document.

Of course he didn't invent it.  Things that happen in nature aren't 
invented, they're discovered. ;)

Similarly, Newton didn't invent gravity.  Aristotle didn't invent 
displacement.

Jim

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On Fri, 15 Apr 2011 09:34:13 +0100, Invisible wrote:

>>> The other Americans I've worked with have all been similarly dense.
>>> Perhaps this is a reflection not of America, but of upper management.
>>> :-P
>>
>> That would be the laziness and "partisanship" showing. One of the Faux
>> elite, who imagine they need know nothing, understand nothing, and do
>> nothing, except make sure other people know, and do things. The logic
>> is, "Why should I have to know that, as long as someone else does, and
>> it works?"
> 
> As an intelligent person, I find this attitude obnoxious.
> 
> This _should_ be the point where I say "ah well, their loss..." Except
> that... well... it isn't, is it?

Where it becomes problematic is when they say "I don't need to know how 
this works, as long as someone else does and it works" and then argue 
with the science of how it works with no understanding of it.

Jim

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>> That doesn't mean that the cooling system can't overload and explode.
>
> Right. But if you knock down a thorium salt reactor, it just gets cold.
> It's basically a big stack of pool-ball sized balls that heat up if you
> get a bunch of them close enough. So if something goes wrong and knocks
> down the wall, it cools off and you send in people in lead-lined
> bulldozers to scoop the stuff up.

If it's so simple and easy, why isn't everyone doing it?

>> Uranium-235 has a halflife is 700 million years.
>
> U-235 isn't that dangerous, tho, unless you pile up enough to interact.
>
> What it also means is that if you spill 100 pounds of U-235 somewhere,
> it's going to take 700 million years for even 50 pounds of it to have
> emitted radiation. That's a very low level of radiation.

How do you work that one out?

> The actual chemical properties are probably more dangerous than the
> radioactive properties if you spread it out widely enough.

Well, yeah, that's probably true enough.

>> That's /halflife/, not the
>> time it takes to degrade completely, just the time for *half* of it to go
>> away. 700 million years is longer than that oil has been in the
>> ground. ;-)
>
> Which tells you that it isn't *that* dangerous or there wouldn't be any
> life in the ground.

It's also an extremely rare element. Not like a reactor core, which is 
make out of pure Uranium...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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>> I'd be rather surprised if you can build a system powered by radiation
>> such that it doesn't use much radiation.
>
> I didn't say that. I said a mistake doesn't leak dangerous radioactivity.

So it's full of radiation, but if you smash it up, it somehow doesn't 
release any radiation? How would *that* work?

> If I said "it's possible to build a car that can hit a wall at 100MPH
> without the passenger getting hurt", would you say "I'd be rather
> surprised you can build a car that won't run into walls."

I *would* be surprised if you can make a car that can withstand a 100MPH 
crash. :-P

>>> The advantage is it's far more efficient to generate the power centrally
>>> and distribute it than it is to generate it locally.
>>
>> Is it?
>
> http://www.scientificamerican.com/article.cfm?id=electric-cars-cost-per-charge
>
> How come I do your googling for you? :-)

And now we have to sit down and figure out who funded them to publish 
that, where they got their data from, what methods they actually used, 
etc. It's not as simple as "it's true, because this random website says so".

>> In that case, just ban *all* forms of lighting! That should create a
>> market
>> demand alright...
>
> Well, banned for everyone but essential legislative services, of course.

LOL. Yeah...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 15/04/2011 05:01 PM, Jim Henderson wrote:
> On Fri, 15 Apr 2011 10:21:37 +0100, Invisible wrote:
>
>> Wind power is great. But... do you really want the whole country to go
>> black every time the wind stops blowing? Similarly, solar power. You
>> realise that the sun is below the horizon for hours at a time, right?
>> And some days, it's just not very sunny. For either of these things to
>> work, you seriously need high-efficiency power storage, so you can
>> collect power when it's there, and store it for when it's not.
>
> And most solar collection and all wind powered systems I've seen actually
> include that storage subsystem.

Last time I heard, storing electricity efficiently is an unsolved problem.

(Apparently current battery solutions aren't very efficient.)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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