Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:What an idiot (Score 0) 270

Frederick's letter claims that another employee set up the Google account and made Williams an administrator, but not the controlling administrator. It says the school locked itself out of the admin account through too many failed password attempts.

Sorry, but that account doesn't belong to the school, it belongs to Williams. If the school got themselves locked out of their own account that's their fault.

Comment Re:Burn in... Improvements? (Score 1) 238

how does the TV know the content was originally 1080p24? If you do inverse telecine on stuff which was originally recorded live interlaced you won't get very good results.

It's very easy for a filter to try reassembling fields into frames, then checking if they match, and perhaps outputting the interlaced fields to the next filter unmodified if they do not.

The pulldown pattern of duplicate fields is quite uniform and consistent, with the exception of the occasional edit, so it's obvious after just a few frames if your guess was wrong.

Comment Re:There's a Practical Charging Limit (Score 1) 198

A Gallon of gasoline is estimated to have 33.41 KwH! (A normal gas engine throws a good portion of that energy away as heat.) That gallon of gas is pretty close to what my typical household uses in the entire day for electricity! So to pull down the equivalent of a couple of gallons of gas in 20 minutes is going to take the equivalent power drain of a sub-station transformer.

That's some very bald-faced lying.

You already said that the theoretical energy of a tank of gasoline is mostly wasted, but then you go on to use that same number anyhow, as if EVs must waste just as much energy, for some reason. In fact electric motors and Li-Ion batteries are very efficient, while gasoline engines are very inefficient, so the numbers.

In fact a Tesla Model S battery ranges from 60-100 kWh depending on how much you spend, so your gas tank is only 2-3 gallons of theoretical gasoline, while still transporting you 300 miles.

A 60kWh charge in 20 minutes would be no problem for businesses. It's only 375A@480V (3-phase). Here's what 1200 amp, 3-phase electrical service looks like:
Does that look like a "sub-station transformer" to you?

A typical house doesn't use a 480 volt industrial power feed. You don't want much more current in the hands of consumers.

Why in the world would you need 20 minute charging AT HOME? What kind of emergency would necessitate that? Two people sharing a car, both commuting 100+ miles to work, on different shifts?

Most everyone else plugs-in their car, then GOES TO SLEEP. Who cares whether it charges in 10 minutes, or 10 hours, AT HOME?

Comment Re:Cold weather? (Score 1) 198

Our car batteries get a little cranky w/o either a trickle changer or a battery pad warmer at those temperatures.

Car starter batteries do terribly in cold weather because they are expected to deliver a huge percentage of their power in a few seconds, when cold. An EV will have a huge battery pack, which is only expected to output a small percentage of its available power gradually over the course of your drive.

In short, you'll have less range when the batteries are cold, but they will always work just fine (no start-up problems), and you might even see your range increase while you drive, as the batteries heat-up from being discharged.

And like you said, all cars in cold climates are pluged-in anyhow, so there's really no extra hassle to worry about, and they can be kept in ideal operating temperatures with inexpensive grid power.

Comment Re:Autonomous Date (Score 1) 198

Those "parlour tricks" do a pretty good job of driving already, another 4 years of machine learning and I think they'll do a stupendous job.

Autonomous cars did a pretty good job of driving a decade ago, too. I'm sure they'll do a pretty good job a decade from now, as well, but like today, still not be quite good enough.

Google's self-driving cars have reported higher incidents of accidents than human drivers, and most of them are limited to low-speeds, and still need human operators to occasionally get them out of trouble.

Comment Re:How many charge/discharge cycles? (Score 1) 198

As I understand it, the main ageing mechanism that kills them is oxidation of the graphite anode, which starts when the cell is manufactured and isn't appreciably affected by usage except for being accelerated somewhat by being stored at high temperatures with low (20%) charge.

That's complete nonsense.

Li-Ion cells absolutely are severely negatively affected by cycling. (PDF)

That's not to say there isn't calendar fade/degradation of Li-Ion cells. Just that it is far less significant than charge/discharge cycle fade. There is some of both, but that's only a significant concern for long-term standby power applications (not a significant issue for EVs).

Anecdotally, I recently swapped the battery in my cell phone. The replacement unit was new, old-stock. It was 4+ years old, manufactured at the same time as the dying battery it was replacing, but works quite nicely. No doubt it's slightly lower capacity than a newly manufactured battery would be, but not noticeably so.

Comment Re:Unlimited? (Score 3, Insightful) 196

Verizon has been very reasonable about allowing people to remain on unlimited plans, they could simply make everyone on one sign up for a current plan if they wished. But they don't

Verizon hasn't been reasonable at all... They've had their asses kicked by the Obama FCC every time they tried to impose limits or restrictions. They've tried not to piss off the FCC, and now that Trump is about to gut the agency, Verizon no longer has anything to worry about, for the next 4 years at least.

Comment Re:BB, RIP (Score 1) 168

Other devices you have to pay by KILOBYTE
Iphone had the first data plan where they didn't meter you

Apple got extremely lucky that their device was the trendy, up-and-coming smart phone *JUST* before 3G came out. 2G data was painfully slow, incredibly expensive, and just worthless for browsing the web.

If the iPhone came out a few years earlier, the hype would have died down as people realized their flashy and expensive Apple product wasn't very useful with slow and expensive data. If another company had been debuting their new, revolutionary smart phone at the time, instead of Apple, the world would look quite different.

Comment Re:cult of mac (Score 1) 168

What was sorely needed though, was a phone that did mobile web browsing and didn't suck. Internet Explorer Mobile sucked, horridly. Every attempt it made to lay out a page on a 320x240 screen was basically an exercise in shuffling cards - it never, ever worked right...but miraculously, even it was a step up from the Blackberry browser, which couldn't do anything right. Showing a full website and pinching in and out to navigate it? That really was incredible for the time.

Opera did mobile browsing right, many years before the iPhone came out, and it was available on multiple platforms.

"The first version of Opera Mobile Classic was released in 2000 for the Psion Series 7 and NetBook, with a port to the Windows Mobile platform coming in 2004. One of Opera Mobile Classic's major features is the ability to dynamically reformat web pages to better fit the handheld's display using small screen rendering technology. Alternatively, the user may use page zooming for a closer or broader look."

Comment Re:Will they only make car batteries? (Score 1) 201

What you'll probably see is a noticeable drop in the price of 18650 cells. Tesla will be transitioning the Model S and Model X to redesigned packs with the new form factor (whether or not they announced itâ"it's just how they roll). That will significantly reduce worldwide demand for 18650s. Unless some cartel behavior comes into play, prices should fall.

That's not really how supply and demand works at this level. Show me the warehouses full of $1 CompactFlash cards, now that TF/SD have replaced them.

There's no guarantee prices will drop at all. If Tesla only gradually reduces orders, then suppliers will slowly reduce their workforce in tandem and all will remain basically equal. Tesla is a big enough customer that they might have contracts to buy cells below market rate, and the loss of that volume could even push suppliers to demand higher prices for the lower volume of sales to satisfy operating costs. And closing down a line (reducing supply, increasing prices slightly) when demand falls is also an option.

Comment Need another zero in there... (Score 4, Funny) 201

cylindrical '2170 cells,'

You're an order of magnitude off there, chief. That would be a hearing-aid battery. They're actually making 21700 cells. Tesla sometimes calls them "'21-70", but omitting the dash and concatenating the numbers makes no sense.

No big deal, I suppose, just a little typo... I still look forward to buying a $350,000 (3350 eur) Tesla Model 3, with its impressive 21 mile (3460km) range and 1550 mph (25kph) top-speed.

Slashdot Top Deals

I don't want to achieve immortality through my work. I want to achieve immortality through not dying. -- Woody Allen