bathat

> What he didn't say was whether or not the car can be normally "partially charged" after a "charging complete" status posted on the car (yes? no?)

The reporter actually touched on this in his rebuttal. He claims that no one ever told him to set the charge mode to max range, instead of "normal," so the car stopped charging when it got to 90%. However, he stops short of actually saying that he wasn't aware of the existence of "max charge" mode.

He also says that nobody told him to have the car charge while he was sleeping. Personally, I see this as complaining that your interior is wet because Ford didn't tell you roll the windows up before driving through the car wash--it ought to be common sense. Maybe it can be forgiven in a new and unfamiliar car, but it sure seems like the author didn't go out of his way to figure out how to operate it.

In the HN thread about the original story, someone noted that he only mentioned he speed after Tesla told him to slow down. It seems that that was a rather prescient comment in light of the recent claims by Musk that the author was driving well in excess of the speed limit and driving briskly.

You ask if the review is "faked." I don't think "faked" is quite the right word, but there were certainly some omissions in the original write-up. By omitting certain facts, I think the author presented the story in a way that isn't the shining pinnacle of honesty. The Model S may very well not be capable of successfully making the trip the author wanted to make. However, if that is the case, the author shouldn't need hide behind technicalities and loaded language in his review.

Look, electric cars are great, and I'm looking forward to the day when I can buy one, but this is BS.

First, the power the run the fan is minuscule. On the order of a few Watts. Maybe a few tens of Watts at most. It's an order of magnitude less than what is needed to run seat heaters (and those have almost no measurable effect on a Model S's range, which is why "range mode" uses seat heat in favor of air conditioning). The energy use you're talking about is enough to move the car an extra few hundred feet after a multi-hundred mile drive.

Second, every ICE has a thermostat on the radiator. It greatly reduces coolant flow to the radiator when the car is warming up, or any other time that the coolant is below optimal temperature. I spent many years in the northern (continental) United States and never encountered a situation where the coolant temperature gauge on an ICE car failed to show normal operating temperature after 10-20 minutes of warm-up time.

The cold-weather fuel economy difference in a conventional car mostly comes down to greater air density.

Since the false water container on top isn't going to be used anyway, what about just filling it with something hostile to microbes, like dilute hydrogen peroxide? If you wanted to get really fancy, you could even add a couple lines marked "max" and "min" and add some plumbing to make the fluid level vary between them.

The current pricing for the different size batteries that Tesla offers implies a cost of ~$500 per kWh (the cost differential between the 40 kWh, 60 kWh and 85 kWh packs is $10k). I read "somewhere" (random stranger on the Internet alert) that the cost of raw materials is in the ballpark of $80 per kWh. Now, I'd think that the current scale of battery production (certainly at least millions of units in the 18650 form factor that Tesla uses) doesn't leave much room to handwave the magic "scale effect" wand. On the other hand, it does seem like there is quite a bit of headroom between $80 (if that is realistic) and $500.

If a large chunk of the delivered cost of a battery is attributable to fixed costs, like R&D, rather than the process of turning the raw materials into a finished battery, then maybe it isn't too implausible that the price could drop by a factor of two (or four). You might be able to glean some that information about that from carefully reading the SEC reports from public battery manufacturers.

Compressed natural gas (ie, not liquefied) is the runner-up to purely battery electric vehicles. The problems are short range (go read the reviews of the Honda Civic GX: the range is comparable to the middle battery option in a Tesla Model S) and lack of natural gas stations.

The second problem can be partially ameliorated by filling at home with a high-pressure compressor (runs on electricity) fed by the same pipe that brings natural gas for your furnace and stove. Unfortunately, that still requires you to plug in the car overnight, just as you would with an electric, because fast high-pressure compressors are still very expensive. The compressor, by the way, costs more than an 80A EVSE for an electric car and adds range more slowly. There are a few public stations that store high pressure gas, but they tend to be at places like airports and taxi maintenance yards, where fleet vehicles congregate (check out Edmund's review of the Civic GX for refill times, though, they aren't nearly as fast as with gasoline). And compressing the gas still requires electricity. It is comparatively easier (and cheaper) to set up an EVSE (the "charger" stand, although it isn't really a charger) for an electric car than to run a gas line and install a gas compressor.

The first problem I mentioned doesn't really have a solution with a short time horizon: You need either more volume (a bigger car) or a tank that can hold more pressure (you think that everyone from SCUBA divers to NASA hasn't been working on that one for the last fifty years?).

Liquefied natural gas has it's own set of problems: people complain about the Tesla Model S losing a few miles of range while parked overnight, but the boil-off from a cryogenic container would be far worse (an uncovered dewar of liquid nitrogen boils off in "a few" hours; a big 150L dewar at 1 bar will last maybe two or three weeks).

It's not that I think natural gas is "bad," it's that as a physicist I can see that we already have technologies that work better (albeit slightly more expensively for now). The only thing natural gas seem to have going for it at the moment is that it is slightly cheaper[1] than a battery-powered car. Unless there is a new and obviously-practicable way to greatly improve the inferior technology in a short amount of time, I don't understand why it is worthwhile to spend money developing it.

[1] The Civic GX seems be to only available in jurisdictions (like California) that require a manufacturers to sell a certain number of "zero emissions" vehicles. Thus, it is probable that Civic GX's are "compliance cars" and that Honda takes a loss on each one sold. If you want to know this for sure, wait a few years until the full restrictions kick in and all "zero emissions" cars are required to actually have zero emissions: If the GX is still sold by then, I'll concede that it is a viable product (though I'd still rather spend my money on a something like a Leaf at that price point).

> One item to consider, Tesla is only going the route of battery powered cars. The majors are investigating multiple different sources, hydrogen, natural gas, compressed air, battery only, simple hybrid, and series hybrids. So as for stepping up their game I am not sure what you think they need to do.

I don't see how that benefits the incumbents. Unfortunately, the realities of physics and economics (to say nothing about total pollution generated) mean that there are really only two choices: Burn liquid hydrocarbons; or store electricity in a battery (or some combination of the two). Tesla is currently pursing the second option and traditional auto manufacturers are using both. Hydrogen, natural gas and compressed air have all the limitations of batteries and more: The technology that goes in the car is more expensive, the infrastructure is more expensive and exists in fewer places (excluding natural gas), range is short, and 'refuling' times are long.

About ten years ago, as an undergrad, I worked on an NSF- and DOE-funded project to use single-walled carbon nanotubes both as a catalyst in hydrogen fuel cells and for hydrogen storage. Unfortunately, the efficiency gains were minimal, and I'm not aware of much[1] progress that has been made since (but I now work in a different sub-field). That means that a practical fuel cell, big enough to power a lightweight vehicle still costs hundreds of thousands to millions of dollars (mostly due to the requirement for large amounts of platinum to catalyze the H2 in to 2H). Frankly, there has been enough money wasted on pie-in-the-sky projects when there is already-existing technology that works (lithium-ion batteries).

If you don't trust a random stranger on the Internet, then please trust the managers of auto companies. Honda has effectively abandoned their FCX Clairity project because it is cheaper to meet CARB (CA Air Resources Board) requirements by buying zero-emissions credits from Toyota, Tesla, or GM. The FCX, by the way, was a hybrid that only used a fuel cell to meet the average load for electricity and batteries to meet the peak load.

[1] You need at least an order of magnitude better catalyst performance before you can even consider using PEM fuel cells in a mass-produced car. Every time I've seen a press release about better fuel cells, they seem to mention a few percent. At the current rate of improvement, it will take a quarter of a century before we even solve one of the show-stoppers for hydrogen cars.

While it may be true that jamming a VOR signal is unlikely to cause a crash without other co-incidental bad luck, consider this: The localizer portion of ILS operates on those frequencies, too.

I don't think it's all that far-fetched to imagine that an unfiltered transmitter like the one described could generate signals which 'trick' the localizer receiver and guide a low-flying airplane into an obstruction which is technically outside, yet near, the approach path. (The wikipedia page on ILS describes how it works, so I won't repeat it here.) AMing the right carrier with 150 and 90 Hz tones (which really means generating carrier + and - 150 Hz and carrier + and - 90 Hz) would cause the localizer to show the plane centered on the glide path, even if it isn't.

Depending on the spectrum of the phone camera's flash LED, you might be able to get away with just putting a diffraction grating in front of the camera. I recall, from reading a TI app note about pulse oximeters a while back, that these work by comparing the relative intensity of IR and a visible-red light transmitted through the finger (and that there was also some way to do it with reflected light). I wonder if there is a clever way to calibrate the grating without any extra hardware?

I think a lot of sites have caught on to the + trick, though, because more are more disallow the + character in the email validator.

It does not appear to me that the second gyro is intended to add reliability. Watch how the gyros move in the video: the rotors rotate in opposite directions and the frames twist in opposite directions to apply force to the vehicle chassis. That is necessary so that vehicle pitch motion is not coupled into vehicle roll motion by the gyro. So if one gyro were to fail, the vehicle would rock side-to-side every time it went over a speedbump.

Now granted, I'm still in (probably) the first third of my life, but one thing I've come to realize is that there is too much stuff for me to learn. Even if all I ever did was sit in a room and learn stuff, I would never learn it all. Not just that, but if I sat in a room and learned only the interesting stuff, I'd still probably croak from natural causes before finishing. And even if that was all I did, why would I want to just sit in a room learning stuff if I never had time to apply it and build interesting things?

Maybe you learn faster than me. So be it. But, given all that--that I don't even have enough time in my life to learn all the interesting, no, fascinating, things that are so boring as to be considered the current scientific consensus--why should I want to waste my time listening to things that are likely to be bullshit? I don't. I don't have time for bullshit, and neither should you. But the thing is this: Just because you exclude the bullshit it doesn't follow that you can't have talks that cover the cutting edge of research in science and the humanities.

Valid point. Question: When congress makes infringement a criminal matter, do you think false and fraudulent copyright claims should be treated a criminal matter (since they would be, essentially, false police reports)?

That is an interesting and difficult problem. What if it were framed a little differently, though: Suppose there were a federal licensing tax. You'd pay, say, 5% of licensing revenue to the IRS for the first 20 years, 25% for the next 20 years, 60% for the 20 years after that, and so on. Obviously these are made-up numbers, but the idea would be that an increasing fraction of the license revenue would go to government.

Can you point to a single instance of someone or some organization being successfully prosecuted for issuing a false or fraudulent DMCA take-down request? Yes, such requests are illegal under current law, but that law is never enforced. Part of the problem (in my, possibly uniformed, opinion) is that the legal standard is too high: you have to "knowingly" issue a false DMCA request, and that is a tough standard to prove in court. There is no penalty for shotgunning take-downs every which way and seeing what sticks (and saying "oops, my bad" for the ones that don't).

Why does issuing a DMCA counter-notification not automatically trigger an investigation by the FBI?

Then there is the problem that DMCA is woefully inadequate to deal with Fair Use. Fair Use is often cited inappropriately to justify unauthorized copying that does not rightfully fall under Fair Use exceptions. However. DMCA makes no such distinction, and it is up to the entity hosting the allegedly-infringing content (i.e., the one to which the DMCA notice is sent) to determine whether the content is actually infringing. Even when an unauthorized copy of a work passes each of the four parts of Fair Use test with flying colors, the DMCA takedown requester is still not in violation of the law you cited. So there is no disincentive to issuing spurious take-down requests.

Well, ok, so 30% thermal efficiency at the power station[1], and 10% loss in the transmission lines[2]? That gives us .3 * .9 * 2.5 = .68, or 68% thermal efficiency. That compares favorably to the manufacturer-claimed 62% efficiency of the gas heater I cited above. I can even imagine a scenario where an architect could design a house so that heat source of the water heater is near the heat sink of the fridge. In that case, the coefficient of performance of both devices would improve.

In case this wasn't obvious before, let me state this very clearly: Over 30% of the energy content of the natural gas used by your water heater goes up the chimney and is not used to heat the water. Gas water heaters and furnaces are NOT 100% efficient.

[1] Wikipedia claims that conventional external combustion (i.e., steam) power plants have a thermal efficiency of 33%.

[2] Wikipedia claims that transmission and distribution losses nationally averaged 6-7% in recent years.

Sorry to go off on a tangent, but,

>Not to mention that gas heaters are simply more efficient for heating to begin with.

Are you sure about that? A heat pump with a COP of, say, 2 is 300% efficient (it is said to have an Energy Factor, EF, of 3). That is, for every Joule of electrical energy supplied to the pump, 3 Joules are added to the water tank. On the other hand, the combustion products of a natural gas heater need to be exhausted outside the building. Unless they are first cooled to the temperature outside, the heater is less than 100% efficient.

Where I live, a Joule from the electric company costs about 2.5 to 3 times as much as a Joule from the gas company. A quick Google search indicates that this type of water heater typically has an EF of 2 to 2.5. The cheapest gas heater I could find on the Home Depot website was over $300 (twice your Mexican one) with an EF of 0.62. So it wouldn't surprise me if the energy cost of an electric is on par with the energy cost of a gas heater, and it would surprise me if the electric actually used more energy. I don't see how you would save thousands of dollars in energy with a gas heater: Even in the worst case (a 2 EF electric heat pump vs. a 0.62 EF gas in a location with a 3x energy cost ratio), the gas only just breaks even.

It's been a while since I was in high school, but aren't students still required to write long-form reports? I recall writing book reports and essays about historical events. In college I distinctly remember having to write a least one multi-page document for most courses (and for virtually all courses outside the hard sciences). Most people stop there, but those continuing on to grad school (even in the hard sciences) will need to write many 5- to 15-page documents, as well as a 50- to 100-page thesis.

I don't doubt that most people will not need a keyboard most of the time, but not needing a keyboard in the house seems more likely to be the niche. The niche will be 23 to 30 year-olds who have finished school but don't yet have kids in school, and the 55's, and up, whose kids have finished secondary school. Perhaps the computer will again be relegated to the spare bedroom / home office, but I can't imagine a scenario for the majority of middle-class households that doesn't have some sort of physical keyboard.

>Fortunately this is counterbalanced by the Oberth effect. Getting to 20% of your orbital velocity requires expending 20% of your rocket's delta-V. And since delta-V is logarithmic in your propellant mass (rocket equation) that could easily translate to needing half as much fuel.

Well, that doesn't really address my point, which was that you need to compare the weight of the hybrid engine to the weight of the extra fuel. The first problem is that an air-breathing engine is going to be something like 3 to 5% of the initial mass, and you have to carry it with you to orbit[1]. The second problem is how the fuel scales:

v_hybrid = 0.8 * v_conventional

Assume both have similar engines:

ln(m_hybrid-initial/ m_hybrid-final) = ln((m_conventonal-initial / m_conventional-final)^0.8)

m_hybrid-intial = (m_conventional-intial / m_conventional-final)^0.8 * m_hybrid-final

let delta equal the expression in parenthesis

m_h-i = delta^0.8 * (m_payload + m_engine) = delta^0.8 * (m_payload + m_h-i * 0.05)

m_h-i * (1 - 0.05 * delta^0.8) = delta^0.8 * m_payload

So the fuel load in a hybrid is going to be:

m_final = delta^(1-0.2) / (1 - 0.05delta^(1-0.2)) m_payload,

The factor in the denominator is what really kills you, and the hybrid is only going to give you a net benefit for deltas less than about 15. So, not only is there not a factor of 2 fuel savings, there isn't any fuel savings at all! Even if you assume an engine weight of only 3% of initial mass, the benefit is only for delta < 35, which is better than just about all actual (as opposed to paper) launchers. By the way, the Shuttle had a delta of about 85-90 for LEO precisely because its designers made the decision to bring wings (which we neglected above) along for the ride to orbit. That also contributed to the 1 in 50 accident rate of that launch system.

And none of this addresses the fact that you are optimizing the f*ck out of one of the least expensive components of launch cost by introducing all sorts of unnecessary complexity.

[1] Ok, I suppose you don't, but then you have to have some way of recovering it, and that adds an enormous amount of complexity to the system.

Using the new L2C signal will require a new receiver, but the current L1 (C/A) signal will continue to be broadcast. So you will not need a new receiver to continue the same level of service.

>LEO requires about 7.8 km/s, Skylon's jet engines can go around 1.7 km/s. You are reaching 20% of your orbital velocity without reaction mass.

Unfortunately, kinetic energy scales as speed squared, so 20% of your orbital speed represents less than 5% of your orbital kinetic energy. To put this in perspective, the difference in gravitational potential energy between LEO and the earth's surface represents about 15% of your total on-orbit energy.

Now, it's true that an air-breathing engine doesn't need to carry reaction mass (and, sometimes, oxidizer), but the air engines add considerable complexity (which is always a bad thing) as well as weight (because you still need to carry a conventional rocket to finish orbit insertion). So what you need to do is ask how the weight penalty of the air engine compares to the weight penalty of carrying extra fuel in a conventional rocket (bearing in mind, of course, that there a pernicious positive feedback loops when scaling a booster).

It might be a good idea to read the Wikipedia article on air rights that kordless linked (the GP of your post). IANAL, but it seems like flying an RC plane in the way you describe is just the moving version of a 'spite poll,' which are not considered a 'reasonable' use of the airspace above the land you own. You can operate an RC drone above your property, you just don't have any particular right to use it to get in the way of anyone else who wants to operate an aircraft above your property.

I'm sure it's mentioned in Moon Shot[1]. Most books about the space race mention it. Houston was just one of several proposed locations which met NASA's official specifications for a mission control site.

One of those specifications was the minimum distance between mission control and the launch site. That specification was revised upward so that it just barely excluded the then-leading site after Rice University agreed to donate the land. It doesn't take a Von Braun to figure out what happened.

[1]http://en.wikipedia.org/wiki/Moon_Shot

The first time I tried to write this comment, I was a little flip, because I'm not sure if you're trolling.

Purging the container is very easy and requires nothing more than fire (which I think Africans have), water (I am sure they have this), a vessel for boiling the water (ditto), and a moment's thought (the linked article seems to suggest this is locally available too). It does not require any vacuum pumps.

Step 1: Fill the vessel with water and start a fire Step 2: Fill the hydrogen container with water and invert (so the open side is down) Step 3: Hold the hydrogen container so that the opening is just below the surface of the water-to-be-boiled Step 4: Wait for water vapor to fill the hydrogen container.

You now have a hydrogen container filled with water vapor and trace amount of atmospheric gases (the ones dissolved in the water and the ones adsorbed to the surface of the container). Since the urea electrolysis process produces only "dryish" hydrogen gas (the borax stage is used to remove water vapor from the as-produced hydrogen), it does not matter that the hydrogen container initially contains water vapor.

At this point, the user can either cap the hydrogen container (which will produce a poor vacuum as the water condenses) or immediately start filling it with hydrogen.

If conservation of borax is important (probably not, since I suspect that it can be dried fairly easily) one could prime the system by purging the hydrogen container with as-produced hydrogen to reduce the water content to an acceptable level before connecting it to the borax stage.

Any pipe to the US would have challenges on the northern end as well. The connection has to connect to something, after all, and the US government could just as easily apply pressure at the point of presence to any backbone provider who peers with "MegaPipe".

It seems like the idea here is to prevent Mega's "legally challenged" (as another commenter put it) servers from being disconnected by going all the way up the 'chain of command' and creating his own backbone. He intends to give the backbone legitimacy (to forestall any funny business at the PoP) by providing free internet to New Zealanders, thus generating large amounts of 'legitimate' traffic on the link.

Edit: Just to be clear, like rdl, I don't actually think this is a worthwhile thing to do.

Obviously breaking it into 1000 mini-comcasts, like AT&T, wouldn't, by itself, do anything useful. I think the unstated assumption is that in addition to breaking up Comcast, you'd also break the franchise agreements in order to allow competing cable companies within each territory.

It's very difficult for a start-up cable company or ISP with an innovative product, say, a la carte pricing, to get going because Comcast can undersell them (or offer the same innovative product) for as long as it takes for the start-up to burn through their capital. They can do this because 1) The start-up's limited capital prevents them from opening in every market at once; and 2) Comcast's national presence allows them to use the profits from one region to subsidize service in the region where the start-up is competing. It's probably cheaper to just buy Comcast than to try to beat them in a race to the bottom.

They probably don't. Just as there is a critical temperature, Tc, at which superconductors stop superconducting, there is a critical current density, Ic, at which they stop superconducting. That places a limit on the amount of energy you can store in a superconducting loop. Then there is also the consideration that Ic scales as approximately 1/Tc, so high-temperature superconductors have a lower critical current density than low-temperature ones.

Indium is only used for the clear ITO electrode, though. So if scarcity of Indium were the only concern, then only the "front" carbon electrode would be relevant--the rest of the photovoltaic structure could be anything you wanted (including Si).

>At risk of being callous, why should they? If an employee already dislikes a company to the point that a recruitment letter angers them, why should the company go out the way to accommodate them?

So that they don't write blog posts like the one we are commenting on? So they don't actively try to convince other (possibly talented) potential employees to ignore your recruiting efforts?

The entire comments section here seems to be "is Google a horrible company to work for and does Google+ suck, or are they merely ok?" If you're looking for new talent, wouldn't you rather have prospective employees asking "is Google a fantastic company to work for or an outstanding company to work for?"

>Given the tax implications, I would also bet the 110v plug-ins will be made illegal for electric cars for "safety" reason ("safety of a state's road tax revenue").

Meh, I don't think they'll need to. Somewhere on the Tesla website there is a cute little calculator that will tell you how long it takes to fully charge the Model S with the various charging adapters. As I recall, the 110V / 12A outlet takes something like 4 or 5 days. That's fast enough that most people could probably keep their drive-to-work car at a mid-range SoC by charging all night and while at work. But that doesn't leave any room to really use the car for any errands. I have a feeling that very few owners would consider that a viable option for long-term ownership.

I opt out, too.

>"So wait, 3oz of fluid in a 3oz container is okay.. but 3oz in a 5oz container is not? Is it more dangerous for some reason?"

As much as I dislike the current set of rules, I feel that if you going to have rules, then you need to make rules which are enforceable. "Containers 3 oz or less" is an enforceable rule[1]. Is it dumb? Yes, because a 3.1 oz container is no more dangerous (certainly not more than around 3% more dangerous) than a 3.0 oz container. "Containers with less than 3 oz of liquid" is not not an enforceable rule. How can the TSA person quickly assess the volume of liquid in the container? He or she can't, which is the problem. You could, of course, give the TSA agent the discretionary authority to allow larger containers with "about 3 oz of liquid," but that's just begging for an equal-protection lawsuit.

[1] Actually, it's not, because, as far as I can tell, the TSA determines the volume of a container by the declared volume on the label. If you really want to bring 5 oz of shampoo, you could probably just make a funny-shaped bottle with a label that says "Shampoo, 2.9 fl oz". Though it would be pretty easy to measure the volume of the entire container via water displacement ("Mr. President, we cannot allow... a thick-walled-container gap!")