Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
×

Comment Not suprising (Score 2, Informative) 205

On a trip to Florida, I found a neat clump of shells in shallow water. I picked it up and put it in a bucket along with some other shells thinking it was interesting. A few moments later I had a pile of shells and an octopus looking up at me angrily. So if it's smart enough to roll itself in shells, using it's suckers to keep them on, it’s not too surprising to me that these ones decided to use coconuts.

Funny thing is that split coconuts probably aren't too common unless people or animals split them.

Science

Aussie Scientists Find Coconut-Carrying Octopus 205

An anonymous reader writes with this excerpt from an AP report: "Australian scientists have discovered an octopus in Indonesia that collects coconut shells for shelter — unusually sophisticated behavior that the researchers believe is the first evidence of tool use in an invertebrate animal. The scientists filmed the veined octopus, Amphioctopus marginatus, selecting halved coconut shells from the sea floor, emptying them out, carrying them under their bodies up to 65 feet (20 meters), and assembling two shells together to make a spherical hiding spot. ... 'I was gobsmacked,' said Finn, a research biologist at the museum who specializes in cephalopods. 'I mean, I've seen a lot of octopuses hiding in shells, but I've never seen one that grabs it up and jogs across the sea floor. I was trying hard not to laugh.'"
Space

Big Dipper "Star" Actually a Sextuplet System 88

Theosis sends word that an astronomer at the University of Rochester and his colleagues have made the surprise discovery that Alcor, one of the brightest stars in the Big Dipper, is actually two stars; and it is apparently gravitationally bound to the four-star Mizar system, making the whole group a sextuplet. This would make the Mizar-Alcor sextuplet the second-nearest such system known. The discovery is especially surprising because Alcor is one of the most studied stars in the sky. The Mizar-Alcor system has been involved in many "firsts" in the history of astronomy: "Benedetto Castelli, Galileo's protege and collaborator, first observed with a telescope that Mizar was not a single star in 1617, and Galileo observed it a week after hearing about this from Castelli, and noted it in his notebooks... Those two stars, called Mizar A and Mizar B, together with Alcor, in 1857 became the first binary stars ever photographed through a telescope. In 1890, Mizar A was discovered to itself be a binary, being the first binary to be discovered using spectroscopy. In 1908, spectroscopy revealed that Mizar B was also a pair of stars, making the group the first-known quintuple star system."

Comment WMD not yet, but perhaps someday? (Score 1) 314

I don't doubt the science behind the LHC or the scenarios presented. But I wonder if it is possible to make a device (probaby insanely expensive and massive like the LHC) whereby the MHB could be accurately force fed like a veal calf untill it hit a critical point (tons - ktons - Mtons) of mass and would be a worthy earth destroyer. Nuclear weapons just destroy a little area and make the world far less habitable. A good size black hole could

Comment Re:Electric cars are not better for the enviornmen (Score 1) 392

You are wrong...

I am always interested in the CO2 output of these pure electric vehicles. After all, right now we power most of the electric grid with coal and until that changes it dosen't make sense to wish or just assert what things out to be instead of just doing some simple research and high school physics calculations.

Let's look at the real data from the real sources...

According to Tesla motors official specifications [teslamotors.com] the motor has a output of 248 peak horsepower (185kW) and 276 ft/lbs (375 Nm) of torque. Also, for full charge it takes "3.5 hours using the Tesla Motors Home Connector at 240 Volts and 70 amps" which for simplicity and because they have neglected to disclose the actual kwh of full empty to full charge at room temperature (capacity will degrade with use) lets assume is 3.5hrs * (240V * 70A) = 58.8 kwh. Most likely this is an overly conservative estimate because of the constant current constant voltage nature of charging lithium batteries. This is more important than battery capacity because it is the load the power plant feels to charge your car and is the important quantity of interest. This will take you 244 miles on average (from same site) of course flat straight stretches will get better but it is the average that is most important. Total is 58.8 kwh/ 244 miles or about .241 kwh/mile. You can do the math on charging, but it should be obvious at this point that it is much cheaper than gasoline since electricity costs from around 7-20 cents/kwh in the US depending on numerous factors.

Now go look at EPA official website for determining CO2 emissions [epa.gov] (in the US) and you can see that generating one kwh gives you 7.18x10^-4 metric tons of CO2. In addition, they also state on the same page you generate 8.81*10-3 metric tons of CO2 per gallon gasoline.

Lets do some simple math. At .241 kwh/mi this gives you (.241 kwh/mi * 7.18x10^-4 metric tons CO2/kwh) = 1.73 x 10^-4 tons of CO2/mile. At 8.81 x 10^-3 metric tons of CO2/gallon (from EPA) then you have the Tesla getting 50.91 MPG equivelant CO2 pollution. Note that hybrid vehicles and diesels both come close to or exceed this value making the CO2 pollution for a pure electric not as rosy as some have been led to believe.

Note that this is bested by emissions from diesel vehicles at this point. Untill fission or fusion or solar or whatever comes on line, and given the cost of these vehicles, it dosent make sense. Even if the battery were somehow cheap *now* it still wouldn't make much enviornental sense over a efficent chemical fuel based design. the best bang for the buck, since CO2 polluters aren't all rich, is to utilize efficent fossil fuel vehicles

Comment Re:The truth is available with high school physics (Score 1) 392

You neglect that electric vehicles cost several times what an efficent chemical vehicle costs. Given that the bulk of CO2 polluters aren't rich, you can get the best effect now with the best $ to effect approach. People can't afford the high monthly payments and would rather pay more for thier fuel (about 6x cheaper for electricity over gasoline).

Also, you may not be aware, but electric motors are well over a hundred years old and have had about the same gains as chemical engines. There haven't been any big changes in the last 20 years compared to batteries - which have had substantial change.

I did not say that enviornmentalsts did ban nuclear power, just that they 'wanted' to do it for enviornmental reasons we now know are not scientfically sound.

Comment Re:The truth is available with high school physics (Score 1) 392

you just cant use that argument now, or for the next decade, or perhaps even for the next 20 years. Wish thinking about what might or is likely to be is not the same as stopping pollution *now* which is what anyone in the field of enviornmental science would say is necessary to make the most positive change now.

you want a quicker end to enviornmental change? Start the masses on efficent chemical power - it is the most cost effective solution for the next decade at least and this is easy to show scientifically.

We could solve so many of these problems if people used rationality, evidence and the scientific foundation provided to us through centuries of effort instead of emotion, hopefulness and 'good intent'. A good analogy is the 'enviornemntalists' who tried to get nuclear power banned, accelerating global climate change and radiological pollution (through coal byproducts).

Comment The truth is available with high school physics (Score 1) 392

I am always interested in the CO2 output of these pure electric vehicles. After all, right now we power most of the electric grid with coal and until that changes it dosen't make sense to wish or just assert what things out to be instead of just doing some simple research and high school physics calculations.

Let's look at the real data from the real sources...

According to Tesla motors official specifications the motor has a output of 248 peak horsepower (185kW) and 276 ft/lbs (375 Nm) of torque. Also, for full charge it takes "3.5 hours using the Tesla Motors Home Connector at 240 Volts and 70 amps" which for simplicity and because they have neglected to disclose the actual kwh of full empty to full charge at room temperature (capacity will degrade with use) lets assume is 3.5hrs * (240V * 70A) = 58.8 kwh. Most likely this is an overly conservative estimate because of the constant current constant voltage nature of charging lithium batteries. This is more important than battery capacity because it is the load the power plant feels to charge your car and is the important quantity of interest. This will take you 244 miles on average (from same site) of course flat straight stretches will get better but it is the average that is most important. Total is 58.8 kwh/ 244 miles or about .241 kwh/mile. You can do the math on charging, but it should be obvious at this point that it is much cheaper than gasoline since electricity costs from around 7-20 cents/kwh in the US depending on numerous factors.

Now go look at EPA official website for determining CO2 emissions (in the US) and you can see that generating one kwh gives you 7.18x10^-4 metric tons of CO2. In addition, they also state on the same page you generate 8.81*10-3 metric tons of CO2 per gallon gasoline.

Lets do some simple math. At .241 kwh/mi this gives you (.241 kwh/mi * 7.18x10^-4 metric tons CO2/kwh) = 1.73 x 10^-4 tons of CO2/mile. At 8.81 x 10^-3 metric tons of CO2/gallon (from EPA) then you have the Tesla getting 50.91 MPG equivelant CO2 pollution. Note that hybrid vehicles and diesels both come close to or exceed this value making the CO2 pollution for a pure electric not as rosy as some have been led to believe.

Note that this is bested by emissions from diesel vehicles at this point. Untill fission or fusion or solar or whatever comes on line, and given the cost of these vehicles, it dosent make sense. Even if the battery were somehow cheap *now* it still wouldn't make much enviornental sense over a efficent chemical fuel based design.

Earth

Submission + - New research uncovers possible improvements in sol (sciencedaily.com)

burtosis writes: Challenging conventional wisdom, new research finds that the number of sunspots provides an incomplete measure of changes in the Sun's impact on Earth over the course of the 11-year solar cycle. The study, led by scientists at the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) and the University of Michigan, finds that Earth was bombarded last year with high levels of solar energy at a time when the Sun was in an unusually quiet phase and sunspots had virtually disappeared. New analysis of climate change models suggests that while there is a strong scientific consensus that there is a man made environmental problem, are we spending enough money on research in order to justify efficiently funding efforts to ameliorate the problem? How do we deal with a serious problem over decades to centuries when our scientific consensus changes on a decades to yearly timeframe and how does that influence public support necessary for change?
Earth

Submission + - World's climate could cool first then warm later

burtosis writes: According to this article Forecasts of climate change are about to go seriously out of kilter. One of the world's top climate modellers said Thursday we could be about to enter one or even two decades during which temperatures cool. "People will say this is global warming disappearing," he told more than 1500 of the world's top climate scientists gathering in Geneva at the UN's World Climate Conference. It makes one wonder if we, as a global society, really are spending enough money on global warming research to justify the efficient expenditure of resources and garner of support necessary to ameliorate the problem.

Slashdot Top Deals

Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky

Working...