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

 



Forgot your password?
typodupeerror

Comment: Not to mention the slippery slope (Score 1) 392

by Late Adopter (#37670606) Attached to: Amazon Pushes For National Internet Sales Tax
If Amazon concedes that states and localities have enforcement powers beyond their borders for taxing purposes, will Amazon also need to be subject to ALL of the sales regulations imposed by their customers' jurisdictions? Will I get a big pop-up saying that a switchknife of the length I've chosen isn't legal in my city? Will they have to check ID for M-rated games?

Comment: Re:BS taxes (Score 1) 639

by Late Adopter (#37343816) Attached to: Amazon Folds In California Sales Tax Deal
It's all a wash as long as total revenue as a percentage of GDP remains the same, right? You're just collecting it from somewhere else (incentivizing/disincentivizing different things).

That said, all the taxes you've listed are probably better for society than sales tax. Disincentivizing consumption and targeting the poor are two things that generally aren't great for an economy.

Comment: Re:Data Security Anyone? (Score 1) 339

by Late Adopter (#37279404) Attached to: Is Tablet Success Bound To Their Crackability?
But what about in a corporate environment, where the OWNER is distinct from the person in physical possession of the device? Can we at least have some basic infrastructure to ensure that when a device is going to be permitted to access sensitive resources/material, it has some verifiability of its state?

Comment: Re:Does anyone (Score 1) 127

by Late Adopter (#37236686) Attached to: Google Is Grooming Chrome As a Game Platform

If you only allow a subset you don't get native speed, you get the speed that your subset of instructions allows.

The inner sandbox uses static analysis to detect security defects in untrusted x86 code. Previously, such analysis has been challenging for arbitrary x86 code due to such practices as self-modifying code and overlapping instruc- tions. In Native Client we disallow such practices through a set of alignment and structural rules that, when observed, insure that the native code module can be disassembled reliably, such that all reachable instructions are identified during disassembly. With reliable disassembly as a tool, our validator can then insure that the executable includes only the subset of legal instructions, disallowing unsafe machine instructions. The inner sandbox further uses x86 segmented memory to constrain both data and instruction memory references. Leveraging existing hardware to implement these range checks greatly simplifies the runtime checks required to con- strain memory references, in turn reducing the performance impact of safety mechanisms.

As long as you weren't trying to write self-modifying code (and note most compilers won't do this), your performance impacts are basically restricted to checking non-local jumps. Not strictly native, but close enough.

not native speed as to sandbox you must create a vm like system.

That's provably untrue. See AppArmor and SE-Linux, both of which operate without creating a virtual machine (only implementing replacement system calls).

Comment: Differential Geometry is the key (Score 1) 358

by Late Adopter (#37236526) Attached to: Ask Slashdot: Math Curriculum To Understand General Relativity?
Differential Geometry will give you the mathematical foundation for expressing non-flat spaces. From there, GR is "just" the Einstein Field Equations and the implications thereof. And compared to, say, quantum mechanics, there's very few solvable exact solutions to make case studies out of (black holes and possible evolutions of the universe, really).

Springer has an OK book on Differential Geometry, and then you want to move on to Gravitation, by Misner, Thorne, and Wheeler.

Comment: Re:Pure LOL (Score 1) 542

by Late Adopter (#37088146) Attached to: What's the Carbon Footprint of Bicycling?

(I am reminded of the time in college when as a grader in a physics class, the students were asked to find how high a pressurized leak on a water tank would shoot into the air. Two student's answers had the water at escape velocity speeds, sending them into orbit the earth.)

I get your point re: reality checking, but as an aside, any velocity straight up without a sustaining acceleration will eventually come back down. Escape velocity is the speed tangential to the surface of the earth (i.e. on the least energetic orbital trajectory) that is in excess of what gravity can keep pulled to the surface (g $lt; v^2/r). And you still have to fight against air resistance trying to decelerate you while you're inside the atmosphere.

Comment: Re:There is no obscenity exemption (Score 1) 397

by Late Adopter (#36635706) Attached to: Court on Video Games: Less Cleavage, More Carnage
That's the "strict constructionist" point of view. Many people (most?) hold a more moderate point of view that the Constitution shouldn't be interpreted in such strict black and white, and that if the Constitution held every exception to the rule the framer's had in mind, and WOULD have had in mind if they could predict all new situations, it would be as long as some of the bills congress passes, printed on 7000 sheets of paper.

I've got all the money I'll ever need if I die by 4 o'clock. -- Henny Youngman

Working...