asharp

First off no, nature doesn't thrive off solar power alone. At the very least hydrothermal vents provide energy to most aquatic life past the thermocline.

I'd also like to point out that the sun produces more radioactivity then anything likely to be found on earth, and fusion as a whole accounts for all the heavy metals ever created in the universe. (just some food for thought).

There are large quantities of fissable materials which are not uranium. For example take thorium, which is roughly as common as lead.

That's a non sequitur.

Look up the first nuclear pile experiments and you'll find out just how primitive you can be and still produce a functioning nuclear reactor.

That makes no sense.

You create some random key K.

You encrypt k using the public key of the recipient, ie. e(k).

You encrypt the message using K.

You send both of those to the recipient. A cyphertext only attack can recover K from your message M. It is not then possible to recover a private key from K.

In neither case do you ever have the private key, as such it cannot ever be recovered from a core dump. In this script it seems like they are simply doing this twice, for some unknown reason.

The problem is that we have fewer IPV4 addresses then we have consumers who wish to consume IPv4 content.

Take our current situation: We still have large swaths of china and india without Internet connectivity, yet we are basically entirely allocated with demand for ipv4 addresses increasing.

V6 used to be hard to implement because older routers/switches implemented their support in software rather then in ASIC. This is now no longer an issue, which is why you see ipv6 connectivity sprouting up around the place. I would expect that when push comes to shove, we will see a fast v6 transition when it becomes a large enough deal for there to be > 0 consumer demand for it.

Interesting, do you have any links as to how they work/how they are constructed/etc?

On the other hand, you can always use thorium deposits, use nuclear waste from other nations as fuel, pull uranium from seawater, etc.

Yeah, there are a few different types. One sits on shore and uses wave power to compress air, which then runs turbines. This is probably the most efficient method i've seen. There are a few others though, like the buoy method, etc.

Solar is about the most reliable solution you can come across, aside from an RTG mostly because it has no real moving parts and as such has no real way to fail.

What will be interesting is if they manage to up the energy density to the point where it is economical to build.

* We currently have massive political pressures blocking the production of nuclear reactors. There is no problem in building it, the problem is in the politics.

Why don't you use the standard openssl RSA encryption function to encrypt the entire file, rather then encrypt a plaintext passphrase?

I don't know of an implementation that uses RSA encryption that doesn't use RSA to encrypt a (heavily padded, very random) key which they then use to encrypt the final payload using say AES or IDEA (in the original PGP).

Starting a rebuttal with the word "wrong" seems rather counter-productive. If you have a reasonable point that disproves mine, then anybody reading it would notice this and as such the "wrong" is not required. If on the other hand, your point does not in fact counteract mine, then making such a strong statement seems rather foolish.

To begin: * Uranite (U3O8) is a major ore of uranium https://secure.wikimedia.org/wikipedia/en/wiki/Uraninite and is in fact mostly uranium by weight. * "Uranium mining is the largest business in Niger and the life expectations is not much about 50 years there." Is an example of 'correlation does not imply causation'. To give you an example, the number of pirates have gone down over the last few hundred years. Global temperatures have gone up over the last few hundred years. From that information alone you cannot say that the lack of pirates causes global warming.

* I'd also mention here that there are large amounts of diamonds sourced from africa. A trade that is very profitable, yet leaves the people themselves with very little money nor increased standard of living.

* From the wikipedia article you specified: "Because uranium ore emits radon gas, uranium mining can be more dangerous than other underground mining, unless adequate ventilation systems are installed.". Assuming these safeguards are met, I fail to see how it would be 2,000,000 times as dangerous as coal mining.

I will, however, correct my previous statement. -Natural uranium has an energy density of 443,000MJ/kg -Coal has an energy density of 32.5MJ/kg.

Hence to produce the same amount of energy as you can produce using one KG of natural uranium you require 13630kg of coal.

Assuming the risk of coal mining is measured in a certain number of fatalities per kilogram mined (equivalent to a certain m^3 mined, given a constant density of the mined material) is R_C and R_U for coal and uranium respectively then the expected number of fatalities per "1kg of uranium equivalent energy" is then R_U and 13630R_C.

As such for coal to be "safer" 13630R_C needs to be < R_U, a statement I consider unlikely.

Eh.

Fossil fuels will destroy the biosphere. They regularly and fairly brutally destroy rather large swaths of it (see nigeria/etc.).

Hydroelectric plants destroy parts of the biosphere. They massively damage aquatic life and fish species and they have the rather nasty fact that if they fail they wash away a good portion of whatever is downstream (read: that city.).

Renewables tend to be very energy disperse, require large amounts of energy/land to produce and generally can't provide baseload power except for hydro power.

At the end of the day, there isn't any perfect answer, but all the effort directed at stopping nuclear power research seems very short sighted, seeing as it is currently the best answer to baseload power that we have.

Nuclear power reactors can be produced without any real proliferation risk, see for example thorium reactors.

Similarly the thorium fuel cycle is a lot clearer, ie. assuming that you can recycle actinide wastes, there is very little radioactivity after the first few hundred years: http://hal.archives-ouvertes.fr/docs/00/04/14/97/PDF/documen...

Finally, if you have waste of any sort that you want to keep away from humans (A large amount of chemical waste would also seem to fit this bill), where else would you put it, aside from the centre of the most geologically stable continent on earth? Thousands of kms from habitation, far from any groundwater, and most likely on a large sheet of granite given the geology of the outback. Assuming it was properly built underground, I can't think of a better place to put it.

Solar power is interesting, but it has two properties which make it less useful then it would first seem.

* First you need to find a place that is very hot and very dry. That generally requires that you move far inland and far north and away from the coastline. This then means that you somehow need to transfer the power to the major cities, which are built almost entirely on the coastline, causing massive amounts of energy loss.

* Secondly on any non-equitorial latitude you have the problem of seasons affecting your baseload capacity. This then means that trying to manage any power grid that derives a substantial amount of its power from solar thermal plants is going to be, well, an interesting problem.

* Finally you will always have the problem of trying to manage these types of power plants, ie. you can't simply "turn up" a solar thermal or photovoltaic plant like you can a gas fired or coal fired plant. This then causes issues when you have a sudden need for power.

Overall though, it is a very interesting source of renewable energy.

Stating that air travel is safer then cars doesn't mean that I wish myself to be strapped upon an early glider and hurled off a cliff.

The fact that one such glider still exists and is apparently in use has no bearing to the current state of the art of aeroplane design. Similarly that one old, outdated and utterly inferior reactor can fail when provoked says nothing of the current state of the art of reactor design.

Strangely enough it takes very little money, nor energy to produce nuclear power. It's very simple at its core. Have a look at the first research reactors and you'll find that you need basically no technology to produce reactors that produce useful amounts of energy.

On the other hand solar power, especially photovoltaics is stupidly complex. Photovoltaics requires semiconductor processes, arguably one of the most complex things ever reliably harnessed by man to create.

Saying that you want to power your computer from a solar cell seems green, until you think of all the energy that went into building that solar cell. All the waste materials, the toxic waste produced in fabrication, the pollution, etc. Then it seems decidedly less green then, say, plugging it in to the wall socket.

It's interesting, but from what i've seen of it (albiet not all that much), it has two major issues.

* It has a low power density, hence requiring large arrays of collectors/etc. this makes it costly to build at scale.

* It generally either takes up valuable land (land by the sea is costly), or it requires lots of engineering to try and build/maintain these things out to sea.

It is very cool tech though.

There are plenty of other designs, most of which get built as test plants, work nicely then never get built again due to political pressure to stick to "safe" designs.

I would have a look at pebble bed reactors, molten salt reactors and heavy water moderated reactors.

long story short, the designs exist, we just can't seem to get rid of the old ones that are currently built and we can't seem to get the new designs built in any sort of scale.

As a quick bit of thought.

Lets say that you need to mine, say 2,715,384x the amount of coal to produce the same amount of energy as you would uranium. (From https://secure.wikimedia.org/wikipedia/en/wiki/Energy_densit...).

Now if mining uranium is less then 2,000,000x more dangerous as mining coal, then per unit of energy generated it is actually safer.

Hence yes, I do think that coal mining is more dangerous then uranium mining, per unit of energy generated.

We just need to build newer reactors.

The problem isn't that we don't have designs that can deal with these sorts of problems. The problem is that we don't have the political strength of will to decommission the older, unsafe plants and replace them with newer, safer plants. Similarly we don't have the political strength of will to do what is required to ensure uncompromised safety, ie. moving spent fuel into secured areas away from power plants, breeding fuel to dramatically reduce the amount of radioactive waste created and burning that waste out to make it less radioactive before it ever needs to be stored, etc.

fusion development hasn't been stopped, especially not for fear of proliferation.

Do you have any information about this subject that I do not?

Also, the major problem with putting solar power plants in deserts is that you lose most of your power trying to get it somewhere useful. Expect this to change when we have commercially viable room temperature (ish) superconductors.

#startups on irc.freenode.org?

What would you suggest? Keeping in mind that basically all renewable sources sans hydroelectric can't be used to provide baseload power and hydroelectric power both has very few potential locations (most of which are in use) and has the nasty failure condition of washing away a good portion of the countryside.

If memory serves, the problem is that it is politically impossible to create some area to place the waste fuel. ie. it would be much safer to move the spent fuel out of the reactor, however there is nowhere for it to go to.

As per point #3, remember that you amortize the cost of r&d along some payback period. As such it does effect your margins.

I do agree with your point though. Decreasing development time is the means to the end of making more money out of the product and making a greater return for your (money/time) investment.

http://www.icsi.berkeley.edu/pubs/networking/onix10.pdf Link, as the internal page viewer is, well, claustrophobic.

I think point 7 needs a slight bit of expansion. -> Don't allow anything sensitive to be accessed from the outside world.

Creating a vpn takes seconds and provides a very strong wall between everybody who isn't you and your vulnerable services (ie. sql server/etc.)

Interesting, and very close to the implementation of Etags.

On the upside, it means that files that haven't been changed won't ever be rerequested without needing a round trip to the remote server.

On the downside, you clutter up caches with "dead" but not yet expired files, and you have to deal with scripts every time you change files, which is likely to decrease the reliability of your site and provide a new point of failure.

Well, no.

Think about it this way: Speed is the number of requests/second a single server can process.

Scalability is the amount of computing power you lose when splitting a job amongst multiple machines.

Intuitively you can think of it like asymptotic complexity. You can have a really fast implementation of quick sort, but at a large enough input size it will be flattened by a very slow version of radix sort.

Similarly you can have the fastest web server on the planet, but if you scale poorly, at some number of nodes even the slowest albiet well scaling system will out perform you.

From what I remember, the problem isn't producing something that parses (for the emitter), the problem is producing something that could still be considered human readable and/or not horribly ugly.