Follow Slashdot stories on Twitter


Forgot your password?

Comment: Re:Seems he has more of a clue (Score 1) 700

by DanielRavenNest (#49581867) Attached to: Pope Attacked By Climate Change Skeptics

> Why don't you show how the current climate changing has anything to do with mankind. The burden of proof of that is on you.

That the concentration of CO2 has risen by 40%, and that CO2 prevents heat from escaping the Earth, thus warming it, are facts that don't need proving. The issue is where is the CO2 coming from? Along with the total concentration going up, the ratio of Carbon-13 to Carbon-12 is changing. Plants slightly prefer the lighter isotope, because it diffuses and reacts faster. The only sources of enough plant-based carbon to account for the 120 ppm added added to the atmosphere are fossil fuels (which were plants once), and deforestation. Both of those are human caused changes. Inorganic sources of CO2, like volcanoes, don't care about isotopes. They don't cause a shift in the ratio, and thus are not the source.

Ice cores keep a record of volcanic eruptions (dust gets trapped), and CO2 levels (trapped bubbles), and the respective isotopes. The oxygen component also has isotopes, that let you measure temperature (water with Oxygen-16 evaporates faster than Oxygen-18). Trees record weather patterns in their growth rings, and solar activity in their Carbon-14 content. Combine all of these, and we have a good historical record going back about a million years and four ice ages. The current changes look nothing like the natual cycles in the past.

Comment: Re:Seems he has more of a clue (Score 1) 700

by DanielRavenNest (#49581785) Attached to: Pope Attacked By Climate Change Skeptics

> These guys deny science because of greed.

Oh, the fossil fuel industry believes in science when it comes to geology and chemistry, that's where they make their money. I think deep in their hearts they believe in climate change too, but push the anti- view simply because it will give them a few more years to sell their product. The writing is already on the wall. India just raised their solar target to 8% of electric capacity in the next few years. China is installing 20 GW this year. Dubai for fuck's sake is installing massive amounts of solar panels, and they are a middle Eastern oil state. Courtesy of their sunny climate, the newest solar farms are coming in cheaper than fossil fuel. Renewable energy is being put in for the most unstoppable reason - it's becoming cheaper than the alternatives.

Comment: Re:Seems he has more of a clue (Score 1) 700

by DanielRavenNest (#49581659) Attached to: Pope Attacked By Climate Change Skeptics

> Contrary to all the theories that – that they are expounding, there should have been warming over the last 15 years. It hasn't happened," said Cruz."

Being from a hot state, Cruz should know that a drink doesn't warm up while the ice is melting. Melting ice takes the equivalent of raising water temperature by 70C, that's why it is so effective in your cold drinks. Well, the world's ice is melting - the Arctic ocean, Greenland, northern permafrost, mountain glaciers, and in the last few years Antarctica. That's soaking up a lot of the heating. And what he's talking about is air temperature, while a 5000 times larger heat sink, the oceans, are being ignored. They are also warming, as evidenced by ocean temperature measurements, but also by global average sea level rise as the water warms and expands. Once the atmosphere warmed a few degrees, which it has, on balance heat is flowing from the air to the water and ice. But the atmosphere is the smallest heat sink. The heat is going elsewhere.

Comment: Re: Do not (Score 1) 133

by DanielRavenNest (#49556879) Attached to: Liquid Mercury Found Under Mexican Pyramid

> I know, right? It wasn't aliens that built the pyramids, or anything supernatural. It's stupid to think that.

Exactly. A civil engineer wanted to figure out how the pyramids were built, so he went around asking the experts - Egyptian stonemasons (modern ones). The most plausible answer they came up with is the "shadouf" - the lever and water bag device for raising water from the Nile to irrigate fields. Pretty much everyone at the time would have been familiar with it. To raise stones for the pyramids, just build a bigger, sturdier version. A 5:1 leverage ratio makes a 2 ton block an 800 lb lift. A bunch of workers hanging their body weight on the lever end would raise the stone a foot or two. You prop the stone with some timbers, shorten the lifting rope, and repeat. When the stone gets to the next level of the pyramid, you rotate the lever arm horizontally and pivot the stone to the next step. A series of shadoufs like this could raise a stream of stones step by step up the pyramid.

In comparison to dragging the stones up a giant dirt ramp (which there is no evidence for), levering the stones up is immensely easier. You merely climb up one step, put your foot in a rope loop, and let gravity do the rest.

Comment: Re:Solar is here to stay (Score 2) 533

by DanielRavenNest (#49505313) Attached to: Utilities Battle Homeowners Over Solar Power

> Now they're just waiting for the products to arrive en masse.

For the Phillippines, that was 2014. They went from 3 MW installed in 2013 to 117 MW in 2014 ( ).

Worldwide, installations are expected to increase from 44.2 GW last year to 57 GW this year ( ). I think we have reached en masse.

Comment: Re:How this should have been prevented... (Score 1) 150

by DanielRavenNest (#49501573) Attached to: Incorrectly Built SLS Welding Machine To Be Rebuilt

> An alternate, plausible chain of events is that NASA originally, disagreed with ESAB and felt the floor fix was unnecessary in the first place

That's not plausible if you understand where the Michoud Assembly Facility is. It's next to New Orleans, and all of the ground around there is soft and swampy. If you are building anything heavy or that needs to be rigid, it needs heavy foundation reinforcement (thick slab, pilings, etc.).

Comment: Re:It would speed up.. (Score 1) 365

by DanielRavenNest (#49474483) Attached to: Can Civilization Reboot Without Fossil Fuels?

> While they'd be intermittent

Solar thermal with hot-rock storage can be nearly around the clock, and modern vacuum-powder insulation can keep the rocks warm a long time.

Also, everyone seems to forget that big hydroelectric dams are massive structures. They aren't going anywhere for centuries. Replacing the generators and water turbines is a small job compared to pouring a million cubic yards of concrete. So even if you lost the tech level to run the dams, you could regain it relatively easily, and have lots of power to work with.

Comment: Re:Economics would be the problem (Score 1) 365

by DanielRavenNest (#49473975) Attached to: Can Civilization Reboot Without Fossil Fuels?

> the forward looking saudis will do what they have to do to be able to compete in the world

The Middle East and Africa are rapidly deploying solar panels ( ) They have an excellent climate for it, and they know the oil won't last forever. The Sun will.

Comment: Re:We have already figured most of this out. (Score 2) 365

by DanielRavenNest (#49473847) Attached to: Can Civilization Reboot Without Fossil Fuels?

Solar cement kilns have been demonstrated. The limestone and shale that are calcined to make Portland Cement don't care how they are heated, They just need to reach a high enough temperature for a while. We mostly use fossil fuels today for the process, but concentrated sunlight works fine.

Comment: Re:False Dichotomy (Score 2) 365

by DanielRavenNest (#49473807) Attached to: Can Civilization Reboot Without Fossil Fuels?

A combination of solar furnaces (mirrors and a steering mechanism to track the Sun), and thermal depolymerization ( ) can break down most anything organic into crude oil type feedstocks. That includes items like paper and animal byproducts. There is lots and lots of feedstock buried in landfills. So to reboot that part of civilization, you can use those ingredients.

Comment: Re:forking and "merging" hardwar designs (Score 3, Insightful) 46

by DanielRavenNest (#49473695) Attached to: The Makerspace Is the Next Open Source Frontier

In the aerospace industry, we had metadata around the actual design documents, and a process for incorporating changes. Some examples are:

* A drawing tree. A complete airplane or other complicated product had a top level drawing, that called out major assemblies (wings, landing gear, engine installation, etc). The major assembly drawings then called out sub-assemblies, in a tree structure, until you get to the parts level. Documents tied to a particular drawing (like engine installation procedure) got the same number as the drawing with a -002, -003, etc added, so you could track what they go with.

* Interface drawings and documents. Between assemblies you defined the interfaces between them - mechanical, dimensional, electrical, etc. You can't change your side of the interface before first consulting the people on the other side, and updating the interface data. That's how you ensure the pieces go together later.

* Requirements tracking. For example, the 747 landing gear has to support a takeoff weight of 880,000 pounds. Therefore there has to be a weights tracking process that assigns weight budgets to the various parts, and reports status back up the tree. Otherwise you can end up with a plane that's too heavy for the landing gear. Anywhere else there is a critical design value with contributions from various parts, you use this method.

All this metadata has to be passed around along with the actual parts drawings and software code. If you don't, then anything too complicated for one person to design is likely to need rework when the pieces of the design are merged.

Comment: Re: Makerspace Utility (Score 2) 46

by DanielRavenNest (#49473565) Attached to: The Makerspace Is the Next Open Source Frontier

Most makerspaces are hobbyist-level workshops. They don't usually have industrial grade software or fabrication machines available, because those are expensive. I'm working on the idea of a "MakerNet", where instead of a converted warehouse space with hobbyist tools and home-made workbenches, you have more commercial-grade machines spread around, either run as small businesses, or owned by groups of more serious hobbyists. For example, a $6,000 lathe might be split among half a dozen people. When you have a more serious project to do, you send the files for the various pieces to the respective machines that can make them. You also send payment, or deduct from a network account, to pay for the raw materials and other items you use up.

So higher quality machines, and people who regularly use them, therefore better output. But networked and distributed cost, so it is affordable on a hobbyist budget, and you have access to machines you can't afford on your own. Makerspaces can certainly be part of such a network. They would just need to have some machines and people that are able to do the better quality work.

It is better to live rich than to die rich. -- Samuel Johnson