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Comment Re:Iron Man's Suit Defies Physics -- Mostly (Score 2, Interesting) 279

Hydrogen peroxide powered rocket packs fly for around 30 seconds, because they have a specific impulse of around 125, meaning that one pound of propellant can make 125 pound-seconds of thrust, meaning that it takes about two pounds of propellant for every second you are in the air. Mass ratios are low for anything strapped to a human, so the exponential nature of the rocket equation can be safely ignored.

A pretty hot (both literally and figuratively) bipropellant rocket could manage about twice the specific impulse, and you could carry somewhat heavier tanks, but two minutes of flight on a rocket pack is probably about the upper limit with conventional propellants.

However, an actual jet pack that used atmospheric oxygen could have an Isp ten times higher, allowing theoretical flights of fifteen minutes or so. Here, it really is a matter of technical development, since jet engines have thrust to weight ratios too low to make it practical. There is movement on this technical front, but it will still take a while.

John Carmack

Comment Re:$14,000 too high? (Score 2, Informative) 575

The Smart "pure" model starts out at "under $12,000" according to their site. Also, to test your theory, I went to toyota.com and configured a Corolla. Once I added in an automatic transmission and power windows/door locks (which is a $500 option on the Corolla!), my MSRP was $16,325. I would imagine that the Corolla will still be a more popular car -- but it's certainly not cheaper.
Google

Google's Best Perk — Transport 342

Reverse Gear writes "The New York Times has an interesting article about how different kinds of fringe benefits are starting to count more in the fight for the best brains in Silicon Valley. The article mainly focuses on Google's high-tech shuttle-bus system, which is quite extensive, covering a majority of the San Fransisco Bay area. The article quotes a transportation expert opining that Google's may be the largest such private system anywhere. One-quarter of the headquarters employees are now using it. A Google software engineer said: 'They could either charge for the food or cut it altogether... If they cut the shuttle, it would be a disaster.'"
Quickies

Submission + - Running Late and Wasting Billions; Punctuality...

Ant writes: "ABC News reports a recent survey found 15 to 20 percent of the United States/U.S. population is "consistently late," especially when it comes to work. Chronic lateness isn't just annoying — it's expensive. American Chief Executive Officers/CEOs are late to eight out of every 10 meetings, according to a 2006 survey by Proudfoot Consulting. And when CEOs are late by 10 minutes every day, it costs the U.S. economy $90 billion in lost productivity. This Reuters article say Peruvians are mostly late that made punctuality program organizers to make campaigns to resolve this issue. Seen on Digg and in one of its Digg comment."
Windows

Submission + - It's official: Vista copy protection 100% cracked

Slinky Sausage writes: "There's been a steady stream of 'sort of' cracks for Vista coming out of the piracy groups, but a crack has been released this morning by "Pantheon" which is doesn't avoid Vista's activation — it exploits it! Apparently despite the requirements for everyone including volume licence customers to activate, Microsoft built in the capability for OEM system builders to pre-install copies of Vista without activating it over the internet. The crack works on any Acer, HP, Lenovo, Hewlett Packard or custom machine (as long as you have the BIOS of that machine available)."
Portables

Submission + - big ram laptops? (beyond 4gb)

Fubari writes: Anybody know when laptops over 4gb might be coming out? Some of the devtools I want to run are just obscene ram-pigs. On the desktop I'm using now (win2003), it sucks up 1.6gb just to boot. By the time I log in and start doing work, it is stretching 2gb.

Move that to vista, add a vm-ware session or two, and I'm worried I'll be pushing 4gb.

I'm torn between buying a 4gb-max laptop now, or some mini-desktop that can fit in a set of luggage wheels. A friend of mine suggested something like this, but my first choice would be something designed to be portable.
Data Storage

Toshiba Touts 51GB HD DVD 236

srizah writes to mention that Toshiba plans to launch a 51 GB HD DVD, with a 1 GB advantage over Sony's Blu-ray disc. From the article: Toshiba has submitted a triple-layer, 51GB HD DVD-ROM disc to the standard's overseer in the hope the technology will be adopted as a standard by the end of the year. If approved, it allow the format to exceed the 50GB storage capacity of rival medium Blu-ray Disc. The HD DVD standard currently defines single- and dual-layer discs capable of holding 15GB and 30GB of data, respectively."
Networking

Submission + - Should a new LAN be entirely wireless?

massysett writes: "I'm in the brand new public library in Rockville, Maryland. Of course there is Wi-Fi for patrons who bring their own laptops. There are also about two dozen Windows PCs throughout to provide catalog and Internet access. I was surprised to notice that all of these public access machines are connected wirelessly, using D-Link expansion cards. The Ethernet jacks on the backs of the machines aren't connected to anything. I'd understand networking the machines wirelessly in an old building, to save the cost of pulling Cat 5. However, this is a brand new building built just for this library, and there is obviously room for cables — the power cords for the computers are coming out of the floors. I would think the low bandwidth of wireless, coupled with the headache of troubleshooting interference and performance issues, would rule out a deploying wireless like this — it's relatively easy to wire a brand new building. I'd also think Cat 5 is more future-proof. Obviously library staff disagreed. How do you think the advantages of wireless would outweigh the disadvantages in a setting such as this?"

It's OK to keep AIMing 305

fooby12 writes "According to the Univeristy of Toronto instant messaging does not hurt the grammar of the people who use it. From the article: "With 80% of Canadian teenagers using instant messaging and adopting its unique linguistic shorthand, many teachers and parents are concerned about the medium's potential to corrupt kids' grammar. But instant messaging doesn't deserve its bad reputation as a spoiler of syntax, suggests a new study from the University of Toronto.""

Dueling Network Neutrality Commentary on NPR 390

cube farmer writes Wednesday National Public Radio featured a commentary by telecom representative Scott Cleland in opposition to Network Neutrality legislation. Thursday Craig Newmark, the Craig behind craigslist, countered that Network Neutrality is essential for consumers. Who made the stronger case?

The Rise and Fall of Corba 304

ChelleChelle writes "Chief scientist of ZeroC, Michi Henning, has an interesting look at the story behind CORBA a once-promising distributed computing technology. Henning provides more than a brief history, in addition to several reasons pinpointing why CORBA fell short, focusing specifically on the OMG's technology adoption process itself. Most interesting is the final discussion on what we can learn from CORBA's decline, particularly in reference to web services."

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