... last time I looked at this, Lithium batteries are around 99% efficient.
Lithium ion batteries are definitely not 99% efficient - wikipedia gives 80-90% range for charge-discharge energy efficiency. The reason is that, despite excellent charge efficiency, the battery's voltage increases during charge and decreases when discharged. For example, 4.2V is the typical charging voltage as the battery approaches full charge, but the open circuit voltage drops below 4.0V after the charge cycle (and a rest period) and the delivered voltage drops significantly lower than that under load.
you'll only get [311 miles] in efficiency mode (0 to 60 in 2 minutes) traveling over flat ground with no AC or accessories.
Aggressive acceleration doesn't reduce efficiency in electric cars the way it does with gas engines, so ahead and step hard on the pedal if you like. Just try to use regen when slowing down as much as possible. Likewise, hills are not really a problem - I live at the base of the Rocky Mountains and find the descents mostly make up for the lowered climbing mileage in my BEV. Hot and cold weather, on the other hand, do reduce range, in some situations very significantly.
hyper-threading... purportedly boosts performance by about 10-20% for multithreaded apps.
10-20% might be the case. I've also read some claims of 30% speed boost from hyperthreading. The boost is highly dependent on workload.
For me, 100% is often the case. I do a lot of tight number theoretic math loops and was astounded to find that one of my typical computations -- with little memory use and essentially no communication -- was 8 time quicker on 4 cores/8 threads compared to the single threaded version. Perfectly efficient! Your mileage will very probably vary, but it works for me.
If they can get most of the Supercharger network off the grid, most electric cars wouldn't be powered by anything other than the sun.
The Supercharges network provides only a small contribution to the lifetime energy use of a Tesla car. You have to include the energy used to build the car and the 80+ percent of charging that is done at home. This study shows 98% of weekday charging occurs at home or work (for car owners with home charging stations). Indeed, I find never having to stop for gas (and very, rarely for electricity) is one of the big perks of plug-in EV ownership.
Also note that point of use generation of renewable energy solves a crucial problem in the renewable energy puzzle: the need to build transmission lines as existing infrastructure reaches capacity. Transmission lines cost about a million dollars per mile and are subject to lots of regional and political considerations.
Kudos to Tesla if they make this work. I'm still trying to wrap my brain around the size of the solar farm needed for a Supercharger station.
I mentioned this association to my doctor. She advised caution in interpreting these results because these PPIs are routinely prescribed to patients at risk for the linked diseases. Anyone know more on this?
Of course, the older H2 blockers can be effective for those who want to avoid PPIs. Better still, some people, including myself, get complete relief by finding a healthy diet that does not trigger acid reflux. (For me, that means cutting down on grains and starchy vegetables, YMMV).
By E. O. Wilson, the myrmecologist/evolutionary biologist, explaining the evolutionary origins of humanity and the inherent conflict between self-promoting and group-benefiting pressures that make us what we are. Fascinating reading filled with tidbits about the variety of life on Earth, finishing with a rebuttal of scientific dogma that demonstrates the vibrant process of science. This book changed my view of the world.
The chapters in The Meaning of Human Existence are collected from earlier writings, giving the book a choppy feel. A longer, more detailed, less anthropocentric, but (at least to me) equally fascinating treatment of the material by the same author is The Social Conquest of Earth.
With manual labor less in demand, the economy will need less people; paying people to not work is pointless and unsustainable.
Hmm... If you want to discuss unsustainable actions, let's talk about fostering an underclass effectively locked into perpetual poverty. What alternatives do you propose?. Note that this sort of approach (negative income tax) has been advocated by free market proponents including Milton Friedman.
My check from Knuth, for finding an arithmetic typo in Vol. 2, is for the amount of $5.16 which includes accrued interest.
Regarding the original question: These books are fantastic, but they are challenging and the bit-miserly focus does not map well to today's typical programming needs. They are frankly too detailed and difficult for many readers. My advice is have a look at them and decide whether you need them to complete your life. If so buy the set and enjoy! If not, you probably won't miss them.
I can't be the only person who can already hear these things...
Maybe you can, but the friends I drove up to today didn't. They were in the roadway in a shopping center parking lot, walking across at a shallow angle. I slowed until it was safe to pass. I pulled up and joked: "watch out for maniacs driving silent cars!" They said they had not heard me driving up.
I'm definitely in favor of requiring these cars to be audible.
Technically the NSA was not doing anything illegal with it's efforts to collect call meta data because they were not specifically barred from doing so.
The problem here is that NSA is a foreign intelligence agency, specifically prohibited from domestic intelligence collecting. So, it actually takes a great deal of effort to justify wholesale collection of data on US citizens by the NSA. The way they did it was by redefining the meaning of "collected" so that it no longer refers to data acquired through surveillance. Only data viewed by an NSA analyst is consideder "collected" under this scheme. Brilliant!
Of course, our foreign partners at GCHQ are said to have unfettered access to this trove of data, which remain conveniently uncollected until NSA sees it.
To make matters worse, this Orwellian justification for extra-legal domestic surveillance was kept secret from both the public at large and most of Congress. And top intelligence officials (I'm thinking about DNI James Clapper) lied to Congress about it when asked.
"Until they became conscious they will never rebel, and until after they have rebelled they cannot become conscious."
And for the record, the Arial Atom is a production car that costs less then 150K that's faster. But since ass hats like yourself
Sorry, but saying "for the record" does not make it true. The Conditions of Sale for an Atom purchased from Sector111 (California dealer) include this: Ariel Atom 3s Are Not Considered To Be Federalized, Production Vehicles And Do Not Necessarily Meet Applicable FMVSS Criteria. Therefore, Ariel Atom 3s Are Not Available With 17-Digit VIN Or PIN Numbers.
Go ahead and try running Autodesk Fusion360 virtualized, if you are so inclined. I run a different Windows only 3D CAD system under VirtualBox (2011 MacBook Pro host) with no problems, performance or otherwise, on small to medium sized models. My Windows CAD VM has no network and I like it that way!
Games are different story, Game performance and compatibility suck with VirtualBox. Parallels is better, with acceptable performance on a monster MacPro for those games that run reliably. VMWare fusion should be even better. In any case, I'm booting native Windows, using BootCamp, to run the latest Windows games.
E-Bike laws in the US vary from state to state, but in general throttle controlled electric motors are allowed for speeds up to 20mph. For example, the new California Electric Bicycle Policy explicitly provides a "type-2" category for this sore of e-bike.
No disrespect intended, but I don't know where GWX Control Panel comes from or what it might do to my system so I followed Microsoft's official instructions: How to manage Windows 10 notification and upgrade options. For those affected by this GWX malware, the process includes downloading and installing a not-automatically-distributed update (KB 3065987 or 3065988), setting a newly available group policy, and adding registry values.
The article is not exactly easy to follow - I do not recommend this approach to my non-techie friends and relatives - but it works, is officially sanctioned, and requires no extension of trust to a third party.
... link it shows the "enviro-left" IPCC predictions vs actual temperature measurements. Not even close.
The Guardian addresses several of your errors interpreting this graph in this article. Perhaps the biggest error is the implication that the models predict specific temperature rises over time. In reality, the projections all included error bounds which, if included, would have show a very different picture.
I will note that those error bounds were pretty broad back in 1990. And that newer models are narrowing those bounds.
Last, a quotation from the article: "The 1990–2012 data have been shown to be consistent with the [1990 IPCC report] projections, and not consistent with zero trend from 1990"
So, my understanding is that Apple is refusing to create a version of iOS that would allow FBI to crack encryption on this one phone because then it can be used to do the same on other phones, right?
In A Message to Our Customers Apples Tim Cook described the software ordered by the judge as a "backdoor" and explained that "once created, the technique could be used over and over again". What exactly he means by "technique" is unclear: It seems to suggest that any weakened version of iOS Apple supplied to the FBI might be installed on other phones. Some observers have suggested that even if the software checks the phone's hardware ID, it might still be compromised. There is merit in this argument given the difficult job of designing and verifying highly secure software coupled with at least one new potential channel (hardware ID spoofing) for attacking these iPhones.
However, I think Cook's argument is actually broader: That the larger risk is the Pandora's box opened by setting a precedent forcing them to undermine the security of their product. If the United States succeeds here, how long will it take for other countries to demand the same access? I find the international implications on the privacy of journalists, dissidents, etc. acting in (even more) repressive countries very worrisome indeed.
OK. Three more things. First, we have good reason to believe that the US National Security routinely lies to the American people and our elected representatives about the value of their security intrusions. "Terrorism!", "think of the children", never mind that the FBI acts illegally (spying on congress, anyone?, Stingray surveillance?) and openly desires to routinely thwart our electronic security. Second, Apple has a lot to gain by proving the security of its products through this fight. Trust in products from US electronics companies is falling due to revelations of pressures to add backdoors (among other things), and the FBI's failure to access this phone is the best kind of evidence that Apple has not compromised it. Third -- and this is complete speculation on my part -- it is entirely possibly that Apple has previously received even worse orders to compromise security, but secretly, under the auspices of a National Security Letter, and that this is really a proxy fight against a secret court with no appeal process.
You just happen to be a member of the crowd to which Bernie is playing. And, obviously, he is doing a good job of it.
Don't ever make the mistake of trusting him. Every action he takes that is not subject to public scrutiny will be a betrayal, as is true of every politician (that succeeds).
Nonsense. Sanders has had a remarkably open and public political career. He has answered questions from the public for an hour every Friday for years on the Thom Hartmann Show and his answers are reassuringly consistent and are backed up by his voting record. Plenty of Republicans in Vermont trust him because he does what he says he will. With regards to the surveillance state, Sander's has been outspoken in his opposition to pervasive data collection, voicing support for Edward Snowden's whistleblowing. Here's and article comparing his stance on NSA spying to that of Secretary Clinton.
I have observed that Sanders has generally narrowed his message in his campaign rhetoric, and specifically seems to avoids nuances of electronic security and privacy during the debates.
I respect the source you quoted (Union of Concerned Scientists). Here are some key findings from that paper:
"Nearly half (45 percent) of Americans live in BEST regions—where an EV has lower global warming emissions than a 50 mpg gasoline-powered vehicle, topping even the best gasoline hybrids on the market."
"Some 38 percent of Americans live in BETTER regions where an electric vehicle has the equivalent global warming emissions of a 41 to 50 mpg gasoline vehicle, similar to the best gasoline hybrids available today."
"About 17 percent of Americans live in GOOD regions—where an electric vehicle has the equivalent global warming emissions of a 31 to 40 mpg gasoline vehicle, making some gasoline hybrid vehicles a better choice with respect to global warming emissions.
Assuming constant miles per person driven across different regions, the average global warming contribution of BEVs works out to be equivalent to cars with 43-53 MPG fuel efficiency - significantly better than your original numbers, and good enough to legitimize green claims for BEVs in the US market.
It's true about electric cars in general, where I live in the USA they get about 35-40 mpg equivelant.
Source?
My i3 is rated at 138 MPGe (that's city driving which is 90+% of its use). As I said, carbon generated when recharging from a coal-burning power plant is far worse than that MPGe number suggests, but 35-40? Maybe in India (which burns mostly coal). Doubtful in the US.
City mileage for Teslas run about 2/3 that of the best BEVs. Still good mileage by most people's standards, and off the charts when compared with similar performance gas powered cars. The i3 vs. Tesla numbers turn around on the highway, with Tesla slightly outperforming the boxy BMW due to lower drag and stable speed (less acceleration of its extra mass).
In my experience efficiency for BEVs has a very different feel than gas powered. Regenerative braking is a small player in the overall efficiency of a car in real world driving - BMW claims about 3% energy savings. Academic papers show savings of up to 10% (presumably in repeated start-stop conditions) for normal electric cars, and better with special purpose vehicles. Getting back to my main point, an electric car's efficiency is far more dependent on drag and road incline than other factors. Quick acceleration kills a gas car's mileage, but barely affects my EV's range.
Watch this video of BMW's I3 factory building new tech vehicles in a new tech factory. Now read TFA and learn that Divergent Technologies process doesn't use 3D-printing for the bodies (too heavy) or even the vast bulk of the chassis - the hyped 3D-process is for glorified lugs (they term them "nodes") used to build a tube frame. Consider the relatively tiny contribution of lugs to the assembly of a fully equipped car and it makes very little difference how those lugs are produced.
Then there's the claim that by printing different styles of lug (and some other parts, but not the bulk of the car) they can easily switch from building one type of car to another. If this is not wishful thinking intended to attract gullible investors, I don't what it is. To make effective use of this, they would need a super-agile assembly line stocked with most of the parts needed for all the vehicles they will possible build. The article admits that 3D-printing doesn't solve the majority of parts needs.
There's also the notion that by 3D-printing parts, replacement parts can be made on demand without special tooling. This is a very good point, and undoubtedly one that traditional car manufacturers are starting to look into, even for parts that may have been cast or otherwised conventionally produced for vehicle production.
Lastly, there's the anti-EV nonsense from Kevin Czinger, Divergent's CEO. Let me say that I believe his 1500lb natural gas-powered concept car has a lower environmental impact a Tesla SUV recharged off today's power grid. Today's electric cars are not a clear win when charged with coal generated electricity. Especially when you consider a heavy EV with very large batteries like that Tesla. The real promise of electric vehicles is their ability to use - and drive the development of - renewable sources of electricity. Green cars of the future will have to be both light and shun fossil fuels.
I agree that posture has significant effects on well being and how we are perceived, but the images I had as a kid of good posture were misguided. Military attention and finishing school book-balanced-on-your-head stiffness are not good example of ideal posture. They are too tense, stressing shoulders and lower back, among other things.
Good posture is balanced and flexible. Imaging partially hanging from a string attached to a point straight above the spine on the top of your head, with relaxed (not slouched) shoulders and back. Instead of rigidly holding a position and pivoting the body at one point, allow the hips and back, legs, shoulder, etc to adapt like an inverted pendulum to maintain balance -- not wiggly, just adaptable.
I hope this doesn't come off as too didactic, but it took me 50 years to begin to learn to move properly and it makes a big difference. At least for me.
... the 132 gallons of water for a single cow... Surely lots of it goes back in to the system.
Good point! A lot of the 132 gallons used for processing a cow should be recoverable. That leaves just 999686 gallons per cow of harder to recycle water. Assuming 4,000,000 gallons of water per ton of beef and 500lbs of beef per "cow" (heifer/steer), that is.
This article has answers for you. Roughly, beef takes 40-80 times the water per pound than crops, but that the total water use. Pork requires roughly 11 times the "blue water" (from lakes, rivers, and aquifers) than veggies, beef about 13 time (in California).
The resonance of the bridge wasn't involved at all. For resonance, the wind would have to match the resonant frequency of the bridge.
From the bridge's perspective, this was most certainly resonance! The air pressure field at the bridge's surface exerted force on the structure with a fundamental frequency very close to the bridge's resonant frequency.
Of course, flutter is a more complete explanation which considers the system of wind+bridge, rather than just the forces acting on the bridge. But isn't that obvious?
Slashdot Mirror
... last time I looked at this, Lithium batteries are around 99% efficient.
Lithium ion batteries are definitely not 99% efficient - wikipedia gives 80-90% range for charge-discharge energy efficiency. The reason is that, despite excellent charge efficiency, the battery's voltage increases during charge and decreases when discharged. For example, 4.2V is the typical charging voltage as the battery approaches full charge, but the open circuit voltage drops below 4.0V after the charge cycle (and a rest period) and the delivered voltage drops significantly lower than that under load.
you'll only get [311 miles] in efficiency mode (0 to 60 in 2 minutes) traveling over flat ground with no AC or accessories.
Aggressive acceleration doesn't reduce efficiency in electric cars the way it does with gas engines, so ahead and step hard on the pedal if you like. Just try to use regen when slowing down as much as possible. Likewise, hills are not really a problem - I live at the base of the Rocky Mountains and find the descents mostly make up for the lowered climbing mileage in my BEV. Hot and cold weather, on the other hand, do reduce range, in some situations very significantly.
hyper-threading ... purportedly boosts performance by about 10-20% for multithreaded apps.
10-20% might be the case. I've also read some claims of 30% speed boost from hyperthreading. The boost is highly dependent on workload.
For me, 100% is often the case. I do a lot of tight number theoretic math loops and was astounded to find that one of my typical computations -- with little memory use and essentially no communication -- was 8 time quicker on 4 cores/8 threads compared to the single threaded version. Perfectly efficient! Your mileage will very probably vary, but it works for me.
And, FWIW, I usually prototype in oCaml :-)
If they can get most of the Supercharger network off the grid, most electric cars wouldn't be powered by anything other than the sun.
The Supercharges network provides only a small contribution to the lifetime energy use of a Tesla car. You have to include the energy used to build the car and the 80+ percent of charging that is done at home. This study shows 98% of weekday charging occurs at home or work (for car owners with home charging stations). Indeed, I find never having to stop for gas (and very, rarely for electricity) is one of the big perks of plug-in EV ownership.
Also note that point of use generation of renewable energy solves a crucial problem in the renewable energy puzzle: the need to build transmission lines as existing infrastructure reaches capacity. Transmission lines cost about a million dollars per mile and are subject to lots of regional and political considerations.
Kudos to Tesla if they make this work. I'm still trying to wrap my brain around the size of the solar farm needed for a Supercharger station.
I mentioned this association to my doctor. She advised caution in interpreting these results because these PPIs are routinely prescribed to patients at risk for the linked diseases. Anyone know more on this?
Of course, the older H2 blockers can be effective for those who want to avoid PPIs. Better still, some people, including myself, get complete relief by finding a healthy diet that does not trigger acid reflux. (For me, that means cutting down on grains and starchy vegetables, YMMV).
By E. O. Wilson, the myrmecologist/evolutionary biologist, explaining the evolutionary origins of humanity and the inherent conflict between self-promoting and group-benefiting pressures that make us what we are. Fascinating reading filled with tidbits about the variety of life on Earth, finishing with a rebuttal of scientific dogma that demonstrates the vibrant process of science. This book changed my view of the world.
The chapters in The Meaning of Human Existence are collected from earlier writings, giving the book a choppy feel. A longer, more detailed, less anthropocentric, but (at least to me) equally fascinating treatment of the material by the same author is The Social Conquest of Earth.
With manual labor less in demand, the economy will need less people; paying people to not work is pointless and unsustainable.
Hmm... If you want to discuss unsustainable actions, let's talk about fostering an underclass effectively locked into perpetual poverty. What alternatives do you propose?. Note that this sort of approach (negative income tax) has been advocated by free market proponents including Milton Friedman.
My check from Knuth, for finding an arithmetic typo in Vol. 2, is for the amount of $5.16 which includes accrued interest.
Regarding the original question: These books are fantastic, but they are challenging and the bit-miserly focus does not map well to today's typical programming needs. They are frankly too detailed and difficult for many readers. My advice is have a look at them and decide whether you need them to complete your life. If so buy the set and enjoy! If not, you probably won't miss them.
Just don't ask for mine. I'm keeping these books.
I can't be the only person who can already hear these things...
Maybe you can, but the friends I drove up to today didn't. They were in the roadway in a shopping center parking lot, walking across at a shallow angle. I slowed until it was safe to pass. I pulled up and joked: "watch out for maniacs driving silent cars!" They said they had not heard me driving up.
I'm definitely in favor of requiring these cars to be audible.
Technically the NSA was not doing anything illegal with it's efforts to collect call meta data because they were not specifically barred from doing so.
The problem here is that NSA is a foreign intelligence agency, specifically prohibited from domestic intelligence collecting. So, it actually takes a great deal of effort to justify wholesale collection of data on US citizens by the NSA. The way they did it was by redefining the meaning of "collected" so that it no longer refers to data acquired through surveillance. Only data viewed by an NSA analyst is consideder "collected" under this scheme. Brilliant!
Of course, our foreign partners at GCHQ are said to have unfettered access to this trove of data, which remain conveniently uncollected until NSA sees it.
To make matters worse, this Orwellian justification for extra-legal domestic surveillance was kept secret from both the public at large and most of Congress. And top intelligence officials (I'm thinking about DNI James Clapper) lied to Congress about it when asked.
"Until they became conscious they will never rebel, and until after they have rebelled they cannot become conscious."
-- George Orwell, 1984
And for the record, the Arial Atom is a production car that costs less then 150K that's faster. But since ass hats like yourself
Sorry, but saying "for the record" does not make it true. The Conditions of Sale for an Atom purchased from Sector111 (California dealer) include this: Ariel Atom 3s Are Not Considered To Be Federalized, Production Vehicles And Do Not Necessarily Meet Applicable FMVSS Criteria. Therefore, Ariel Atom 3s Are Not Available With 17-Digit VIN Or PIN Numbers.
Go ahead and try running Autodesk Fusion360 virtualized, if you are so inclined. I run a different Windows only 3D CAD system under VirtualBox (2011 MacBook Pro host) with no problems, performance or otherwise, on small to medium sized models. My Windows CAD VM has no network and I like it that way!
Games are different story, Game performance and compatibility suck with VirtualBox. Parallels is better, with acceptable performance on a monster MacPro for those games that run reliably. VMWare fusion should be even better. In any case, I'm booting native Windows, using BootCamp, to run the latest Windows games.
E-Bike laws in the US vary from state to state, but in general throttle controlled electric motors are allowed for speeds up to 20mph. For example, the new California Electric Bicycle Policy explicitly provides a "type-2" category for this sore of e-bike.
No disrespect intended, but I don't know where GWX Control Panel comes from or what it might do to my system so I followed Microsoft's official instructions: How to manage Windows 10 notification and upgrade options. For those affected by this GWX malware, the process includes downloading and installing a not-automatically-distributed update (KB 3065987 or 3065988), setting a newly available group policy, and adding registry values.
The article is not exactly easy to follow - I do not recommend this approach to my non-techie friends and relatives - but it works, is officially sanctioned, and requires no extension of trust to a third party.
... link it shows the "enviro-left" IPCC predictions vs actual temperature measurements. Not even close.
The Guardian addresses several of your errors interpreting this graph in this article. Perhaps the biggest error is the implication that the models predict specific temperature rises over time. In reality, the projections all included error bounds which, if included, would have show a very different picture.
I will note that those error bounds were pretty broad back in 1990. And that newer models are narrowing those bounds.
Last, a quotation from the article: "The 1990–2012 data have been shown to be consistent with the [1990 IPCC report] projections, and not consistent with zero trend from 1990"
So, my understanding is that Apple is refusing to create a version of iOS that would allow FBI to crack encryption on this one phone because then it can be used to do the same on other phones, right?
In A Message to Our Customers Apples Tim Cook described the software ordered by the judge as a "backdoor" and explained that "once created, the technique could be used over and over again". What exactly he means by "technique" is unclear: It seems to suggest that any weakened version of iOS Apple supplied to the FBI might be installed on other phones. Some observers have suggested that even if the software checks the phone's hardware ID, it might still be compromised. There is merit in this argument given the difficult job of designing and verifying highly secure software coupled with at least one new potential channel (hardware ID spoofing) for attacking these iPhones.
However, I think Cook's argument is actually broader: That the larger risk is the Pandora's box opened by setting a precedent forcing them to undermine the security of their product. If the United States succeeds here, how long will it take for other countries to demand the same access? I find the international implications on the privacy of journalists, dissidents, etc. acting in (even more) repressive countries very worrisome indeed.
OK. Three more things. First, we have good reason to believe that the US National Security routinely lies to the American people and our elected representatives about the value of their security intrusions. "Terrorism!", "think of the children", never mind that the FBI acts illegally (spying on congress, anyone?, Stingray surveillance?) and openly desires to routinely thwart our electronic security. Second, Apple has a lot to gain by proving the security of its products through this fight. Trust in products from US electronics companies is falling due to revelations of pressures to add backdoors (among other things), and the FBI's failure to access this phone is the best kind of evidence that Apple has not compromised it. Third -- and this is complete speculation on my part -- it is entirely possibly that Apple has previously received even worse orders to compromise security, but secretly, under the auspices of a National Security Letter, and that this is really a proxy fight against a secret court with no appeal process.
You just happen to be a member of the crowd to which Bernie is playing. And, obviously, he is doing a good job of it.
Don't ever make the mistake of trusting him. Every action he takes that is not subject to public scrutiny will be a betrayal, as is true of every politician (that succeeds).
Nonsense. Sanders has had a remarkably open and public political career. He has answered questions from the public for an hour every Friday for years on the Thom Hartmann Show and his answers are reassuringly consistent and are backed up by his voting record. Plenty of Republicans in Vermont trust him because he does what he says he will. With regards to the surveillance state, Sander's has been outspoken in his opposition to pervasive data collection, voicing support for Edward Snowden's whistleblowing. Here's and article comparing his stance on NSA spying to that of Secretary Clinton.
I have observed that Sanders has generally narrowed his message in his campaign rhetoric, and specifically seems to avoids nuances of electronic security and privacy during the debates.
Li-air batteries gain mass as they discharge because the process consumes atmospheric oxygen.
I respect the source you quoted (Union of Concerned Scientists). Here are some key findings from that paper:
"Nearly half (45 percent) of Americans live in BEST regions—where an EV has lower global warming emissions than a 50 mpg gasoline-powered vehicle, topping even the best gasoline hybrids on the market."
"Some 38 percent of Americans live in BETTER regions where an electric vehicle has the equivalent global warming emissions of a 41 to 50 mpg gasoline vehicle, similar to the best gasoline hybrids available today."
"About 17 percent of Americans live in GOOD regions—where an electric vehicle has the equivalent global warming emissions of a 31 to 40 mpg gasoline vehicle, making some gasoline hybrid vehicles a better choice with respect to global warming emissions.
Assuming constant miles per person driven across different regions, the average global warming contribution of BEVs works out to be equivalent to cars with 43-53 MPG fuel efficiency - significantly better than your original numbers, and good enough to legitimize green claims for BEVs in the US market.
It's true about electric cars in general, where I live in the USA they get about 35-40 mpg equivelant.
Source?
My i3 is rated at 138 MPGe (that's city driving which is 90+% of its use). As I said, carbon generated when recharging from a coal-burning power plant is far worse than that MPGe number suggests, but 35-40? Maybe in India (which burns mostly coal). Doubtful in the US.
City mileage for Teslas run about 2/3 that of the best BEVs. Still good mileage by most people's standards, and off the charts when compared with similar performance gas powered cars. The i3 vs. Tesla numbers turn around on the highway, with Tesla slightly outperforming the boxy BMW due to lower drag and stable speed (less acceleration of its extra mass).
In my experience efficiency for BEVs has a very different feel than gas powered. Regenerative braking is a small player in the overall efficiency of a car in real world driving - BMW claims about 3% energy savings. Academic papers show savings of up to 10% (presumably in repeated start-stop conditions) for normal electric cars, and better with special purpose vehicles. Getting back to my main point, an electric car's efficiency is far more dependent on drag and road incline than other factors. Quick acceleration kills a gas car's mileage, but barely affects my EV's range.
Watch this video of BMW's I3 factory building new tech vehicles in a new tech factory. Now read TFA and learn that Divergent Technologies process doesn't use 3D-printing for the bodies (too heavy) or even the vast bulk of the chassis - the hyped 3D-process is for glorified lugs (they term them "nodes") used to build a tube frame. Consider the relatively tiny contribution of lugs to the assembly of a fully equipped car and it makes very little difference how those lugs are produced.
Then there's the claim that by printing different styles of lug (and some other parts, but not the bulk of the car) they can easily switch from building one type of car to another. If this is not wishful thinking intended to attract gullible investors, I don't what it is. To make effective use of this, they would need a super-agile assembly line stocked with most of the parts needed for all the vehicles they will possible build. The article admits that 3D-printing doesn't solve the majority of parts needs.
There's also the notion that by 3D-printing parts, replacement parts can be made on demand without special tooling. This is a very good point, and undoubtedly one that traditional car manufacturers are starting to look into, even for parts that may have been cast or otherwised conventionally produced for vehicle production.
Lastly, there's the anti-EV nonsense from Kevin Czinger, Divergent's CEO. Let me say that I believe his 1500lb natural gas-powered concept car has a lower environmental impact a Tesla SUV recharged off today's power grid. Today's electric cars are not a clear win when charged with coal generated electricity. Especially when you consider a heavy EV with very large batteries like that Tesla. The real promise of electric vehicles is their ability to use - and drive the development of - renewable sources of electricity. Green cars of the future will have to be both light and shun fossil fuels.
I agree that posture has significant effects on well being and how we are perceived, but the images I had as a kid of good posture were misguided. Military attention and finishing school book-balanced-on-your-head stiffness are not good example of ideal posture. They are too tense, stressing shoulders and lower back, among other things.
Good posture is balanced and flexible. Imaging partially hanging from a string attached to a point straight above the spine on the top of your head, with relaxed (not slouched) shoulders and back. Instead of rigidly holding a position and pivoting the body at one point, allow the hips and back, legs, shoulder, etc to adapt like an inverted pendulum to maintain balance -- not wiggly, just adaptable.
I hope this doesn't come off as too didactic, but it took me 50 years to begin to learn to move properly and it makes a big difference. At least for me.
... the 132 gallons of water for a single cow... Surely lots of it goes back in to the system.
Good point! A lot of the 132 gallons used for processing a cow should be recoverable. That leaves just 999686 gallons per cow of harder to recycle water. Assuming 4,000,000 gallons of water per ton of beef and 500lbs of beef per "cow" (heifer/steer), that is.
This article has answers for you. Roughly, beef takes 40-80 times the water per pound than crops, but that the total water use. Pork requires roughly 11 times the "blue water" (from lakes, rivers, and aquifers) than veggies, beef about 13 time (in California).
The resonance of the bridge wasn't involved at all. For resonance, the wind would have to match the resonant frequency of the bridge.
From the bridge's perspective, this was most certainly resonance! The air pressure field at the bridge's surface exerted force on the structure with a fundamental frequency very close to the bridge's resonant frequency.
Of course, flutter is a more complete explanation which considers the system of wind+bridge, rather than just the forces acting on the bridge. But isn't that obvious?