I performed an experiment to see what the differences were between semi-automatic pistols and revolvers. The advantage of shooting under water is that you can see the boundary of the gas flow fields almost perfectly.
Category Archives: Tech
No Cats Were Harmed in the Making of this Animation
Mars Science Laboratory (Curiosity Rover) Mission Animation
Not Coming Soon: the iPhone Workout
Dot Physics: Can You Charge Your Phone by Typing?
The feasibility of charging a phone by typing, and by other means.
When Sand Castles are Not Enough
Billionaire sheikh carves his name in desert so big it can be seen from SPACE
The name is two miles across — with letters a kilometre high. It is so huge that the “H”, the first “A” and part of the “M” have been made into waterways.
That Other Thing That Causes One to Envy 007
Driving 007: A History of Bond Cars
Detailed breakdown of the tricked-out Aston Martin DB (imagining Q saying “Pay attention, 007!” optional) and a timeline of the cars.
Tea, Earl Grey, Hot
Not quite there yet. But we have chocolate printing, and now 3D printing can make moving parts.
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable and easier to use than other additive manufacturing technologies.
A Wonderful Discovery
Did We Go With the Best, or the Most Convenient?
Fukushima: Nuclear power’s VHS relic?
A brief history of nuclear power and the politics that goes along with it, in an attempt to determine whether we opted for designs we use because they were the best, i.e. did the US opt for light water reactors just because we had developed enrichment technology.
There is at least one omission, though.
The top US priority was to develop a reactor capable of powering submarines. A naval officer with a reputation for getting things done, Hyman Rickover, was appointed to lead the task.
Submarine reactors need to be small and compact, and avoid the use of materials such as hot sodium that could prove an explosive hazard.
The light water reactor, with the water under pressure to prevent it from boiling and turning to steam, was Rickover’s choice. It quickly entered service powering the Nautilus, the world’s first nuclear submarine.
The article fails to mention that the USS Sea Wolf (SSN-575), the second nuclear submarine in the US navy, had a sodium-cooled reactor. This kind of reactor has to have a secondary loop to make steam, and that means you run the risk of a primary-to-secondary leak. Sodium + water. As pointed out, and as any chemist or physicist who hangs out with those liberal alkali metals (way over on the left of the periodic table), or anyone who has seen a video knows, bad things™ can happen when you mix them. But the technology wasn’t simply ignored, which puts this account on a bit of shaky ground.
It's not Five Joe Biden Sound Bites
That would be a pentagaffe
Meet Your Sponsor: Metro Diverse Service’s Panterragaffe: A Pedal-Powered Walking Machine
Panterragaffe is a pedal powered two person walking machine, a walking bicycle. The name has a few elements to it. It’s a play on pantograph, which is a mechanism for copying drawings, since it’s similar to the leg mechanism. Also; Pan – all or spanning. Terra – earth. Gaffe – an unintentional act causing embarrassment to it’s originator or just goofy-ness. A bit of goofy-ness for everybody. To most people the name doesn’t mean anything, therefore its meaning is flexible.
The Good, the Bad and the Misleading
EIA Report: Renewables Surpass Nuclear Output
Let’s start out with the bad and misleading.
Looking at all energy sectors (e.g., electricity, transportation, thermal), production of renewable energy, including hydropower, has increased by 15.07 percent compared to the first quarter of 2010, and by 25.07 percent when compared to the first quarter of 2009. Among the renewable energy sources, biomass/biofuels accounted for 48.06 percent, hydropower for 35.41 percent, wind for 12.87 percent, geothermal for 2.45 percent, and solar for 1.16 percent.
Biofuels, unfortunately, includes ethanol. In fact, it’s probably mostly ethanol and if ethanol production represents a net gain in energy over the energy used to make it, it’s by a very slim margin. Not only do we mandate its production and inclusion in gasoline in the US, it’s also subsidized (the good news is that the subsidy is scheduled to end, and there’s a chance it won’t be renewed) and diverting land use to corn for ethanol has driven food prices up. Touting a huge increase in the production of ethanol is not good, and it really shouldn’t count as energy production.
I’m not sure where all the additional hydro power is coming from, though. If it’s a rebound in areas that were previously seeing droughts and production is just a return to the norm (or a spike from e.g. above-average snowmelt) then it’s a little misleading as well.
But there is good news:
In terms of actual production, renewable electrical output increased by 25.82 percent in the first three months of 2011 compared to the first quarter of 2010. Solar-generated electricity increased by 104.8 percent, wind-generated electricity rose by 40.3 percent, hydropower output expanded by 28.7 percent, and geothermal electrical generation rose by 5.8 percent. Only electricity from biomass sources dropped — by 4.8 percent. By comparison, natural gas electrical output rose by 1.8 percent and nuclear-generated electricity increased by only 0.4 percent while coal-generated electricity dropped by 5.7 percent.
We are installing solar and wind, and coal use went down. Yay!