Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×

Comment Re:Political/Moral (Score 1) 305

No, it's basic human nature to kick the can down the road, nothing exclusive to politicians. Look at things like IPv4 space exhaustion - we're still kicking the can down the road right now and we'll continue to do so until it becomes so painful we reluctantly start transitioning stuff to IPv6. Same for fossil fuels, "conventional sources" have already peaked and the cost of energy is just going to go up, but we will do the minimum possible and kick the can down the road until it becomes so painful we're forced to change.

Comment Re:Political/Moral (Score 2) 305

Lots of people predicted it. I'm not entirely familiar with the US housing bubble, but in the UK the bubble collapse could be seen from a mile off. I remember yelling pointlessly at the radio when someone from one of the demutualized building societies was trying to justify lending an even more stupidly massive amount of money to people charging interest only "because we want to make property affordable" when it was doing the exact opposite (fuelling the bubble and making it more unaffordable). I also remember discussing it with my Dad on numerous occasions who had got caught up in all the hype. The problem is people got so greedy (both banks and customers alike) with the banks breathlessly falling over themselves to give people mortgages on ever more unsustainable and ridiculous terms, and customers falling over themselves to take them including lying on mortgage application forms, it was obvious that it would only take a slight upset in the economy to make the whole thing come crashing down. It was so blatantly unsustainable. Anyone who wasn't one of the breathless banks or customers could see it coming. The only thing that wasn't entirely predictable was the timing of the burst or the cause of the burst. That upset at least here was skyrocketing energy prices causing all the people who had got mortgages so big they were living paycheque to paycheque with nothing left over to begin defaulting as increased fuel and food costs demolished their non-existent reserves.

Comment Re:What evidence do you have of Gates intelligence (Score 1) 198

No, Microsoft's domination is down to pure luck.

If Compaq hadn't cloned the PC BIOS, or the IBM PC been a flop, Microsoft would have been just a page in history now along with Lotus, Ashton-Tate and various other software houses that got borged by IBM and other large companies. With no IBM PC, MS-DOS would never have sold much, and would never have been the "Microsoft tax" that bankrolled the first versions Windows and Microsoft Office. Even Intel might be a secondary player today, it may have been Zilog who became Chipzilla as they became the preferred supplier for CP/M machines and their 16 bit (and later 32 bit) follow ons, with companies like NEC or SGS or possibly Mostek being where AMD is now as they were Zilog second sources. And Digital Research (CP/M vendor) would be the big bad monopolist instead of Microsoft.

Comment Re:FM (Score 1) 101

The size and construction of the head probably makes quite a lot of difference. I have an old Dallas D banjo ukulele (a George Formby branded one, no less) and the head had an inner hoop in it which makes the effective area of the head a bit smaller than the entire diameter. As such the overtones are softer and it sounds less "banjoey" (but still very different from a standard ukulele). The other consequence of the banjo uke head is that if you play a chord like F# where one string is not strummed, you need to mute the string that's not played otherwise the head will cause the string to vibrate and make the chord sound awful.

Comment Re:Seems plausible... (Score 2) 104

You can buy hardware from a factory a la carte. I've done it. There are quite a few companies doing prototyping services where you can do this for easily affordable sums of money.

I've had a small run (100 units) of an ethernet board I designed made in a factory. The board was a 100mm x 60mm 4 layer PCB. I supplied the gerbers and a BOM and a month later I had 100 boards back (I did put on the through hole parts myself). It cost me a couple of grand to do, they could do it cheaper than I could if I had ordered the parts off Farnell and soldered them onto the boards myself. Hardware is much easier to do today on a shoestring budget than it was even 5 years ago.

Now it's different if you're needing an ASIC - then you're looking into spending a couple of million. But off the shelf BTLE SoCs already exist.

The thing I find implausible about this Kickstarter is that they are attempting to break the laws of physics, not that you can't make a pretty decent sized prototype run on the funding they had.

Comment Re:Seems plausible... (Score 1) 104

They say their device requires an average of 36 microamps. Even if the chip they use only runs on 1 volt, that would be 36 microwatts (it's going to be more than that, I expect their chip is more like 1.8v). They claim the tag will just run on the typical ambient signal from things like WiFi access points. Their antenna at most is going to be half an inch on each side, and the most they can possibly harvest will be less than 1 microwatt even with 100% efficiency.

The antenna won't be much use for getting power off broadcast radio signals. It's far too tiny. Don't forget a crystal set requires not only a very long antenna suitable for the AM radio band, but a good connection to ground, too, so that it can make enough current to run the crystal radio. This thing doesn't have a ground connection.

Comment Re:This fake too? (Score 2) 448

They plan to power a dogtag sized Bluetooth device by harvesting typical WiFi signal power.

The antenna will be at most about half an inch on each side (0.0125 meters, for a total area of 0.00015625 square meters.
Near a wireless network station used in homes and offices, the field intensity is typically below 0.5 mW per square meter.
Further upthread, someone posted the power required by a modern, low power Bluetooth chip, in its lowest powered sleep mode it requires a current of 900nA and 1mA when idle. Let's say it operates on 1 volt (it's probably 1.2v) so we will actually underestimate its power requirements by saying in its lowest powered sleep mode it requires only 900nW (that's 0.0000009 watts).
At 0.5mW (or 0.005 watts) per sq. m, the maximum energy a dogtag sized device, assuming 100% efficiency (not possible) will be able to harvest is 0.005 * 0.00015625 watts of power. This will work out to about 780nW.
780nW is less than 900nW. QED.

And that's giving them the benefit of the doubt (100% power efficiency, and a lower working voltage for the Bluetooth chip that it probably uses, and only considering the chip being in sleep mode, its lowest possible power mode, and not considering at all any other circuits the device will need - it will need more than just a bluetooth module, it'll need at least a minimal microcontroller of some sort).

Comment Re:Imagine a bike that only needs tires and brakes (Score 1) 345

You'd not want a hub motor because it increases unsprung weight which has an adverse effect on handling. Same with electric cars - Tesla for instance doesn't use hub motors but the traction motor for the Model S is attached to the structure of the body.

Then again, we are talking about a Hardly Rideable rather than a motorcycle...

Mars

Elon Musk: I'll Put a Human On Mars By 2026 275

An anonymous reader writes Elon Musk says that he'll put the first human boots on Mars well before the 2020s are over. "I'm hopeful that the first people could be taken to Mars in 10 to 12 years, I think it's certainly possible for that to occur," he said. "But the thing that matters long term is to have a self-sustaining city on Mars, to make life multiplanetary." He acknowledged that the company's plans were too long-term to attract many hedge fund managers, which makes it hard for SpaceX to go public anytime soon. "We need to get where things a steady and predictable," Musk said. "Maybe we're close to developing the Mars vehicle, or ideally we've flown it a few times, then I think going public would make more sense."

Slashdot Top Deals

He has not acquired a fortune; the fortune has acquired him. -- Bion

Working...