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

typodupeerror

## Comment isp "vpn". Social security numbers (Score 1)111

Their ISP would be more than happy to set up each hospital and office building with a "dedicated virtual circuit", which is basically a VPN handled and enforced by the ISP using their carrier-grade equipment. The ISP will ensure that the black network can't access the internet (and the internet can't access the black network). One thing ISPs can do pretty well is take AWAY your internet access. All systems with confidential data are connected only to tge bkack network, which interconnects the various locations.

You do NOT need each workstation to have general internet access in order to connect them to your (virtual) WAN.

Additionally, the various workstations shouldn't have access to social security numbers anyway, even via the local network. Unless you're the social security administration or the IRS, you probably shouldn't be storing social security numbers. If some specific legacy system really has to have social security numbers, isolate that system behind a one-way trapdoor. It shouldn't have general internet accessibility.

## Comment velocity cubed, of course. Thanks. (Score 1)442

Power is actually proportional to velocity cubed. Velocity squared is the amount of energy per unit mass, times the number of units of mass that go by per second (velocity again). This makes your point even stronger...

Thanks for that. Yeah, velocity squared would be the right thing for the energy of an object, such as a car, correct? Or for a cubic yard of air. Also, higher velocity means more cubic yards flow past each minute, so that's the multiplier I forgot. Is that right?

So 25x25x25 = 15,625 but 10x10x10 = 1000.
Meaning, the power at 10 MPH is just 6% of rated capability at 25 MPH.

I actually thought the 10 MPH number in my initial post sounded a little high in comparison.

## Comment Idealist == ignorant? (Score 1)442

I said proponents are often idealists. Do you not know the difference between idealist and ignorant? If not, you may in fact be ignorant.

If you'd care to become less ignorant, here's a good overview of the physical limits of turbines:
https://dspace.lasrworks.org/b...

> and by implication identifying yourself as a renewable energy opponent

Yep, THAT'S why I advocate renewable energy that works, like using the sun as a source of heat. You might have noticed, the sun is really good at making things hot.
Were I an opponent of deploying renewable energy, I'd encourage people to focus on renewable scams that can never work on a large scale, like pretending that the sun is a source of electricity rather than a source of heat.

## Comment We'd do well to stop increasing demand (Score 1)442

> If we reduce the demand for hydrocarbon energy by 30%

For the last 2,000 years or so, the demand has just kept going up, lately at a pretty fast pace. Therefore I don't think a 30% reduction is too likely. If we did some reasonable steps, like solar HEATING rather than wasting all of our time and resources into trying to make the sun a source of electricity, we could get close stabilizing the demand, having the demand stop increasing.

## Comment adiabatic definition: does not get rid of heat (Score 1)62

> From the article:
> "When outside air temperature is too warm for free cooling, the data center’s adiabatic cooling system

Which is funny, because the word adiabatic means something that does not get rid of heat, or draw in heat, from the outside.
An adiabatic system would cool the building by drawing a vacuum, sucking all of the air out of the building. The decreasing air pressure would lower the temperature for a few minutes. Since you can't keep lowering the air pressure below absolute vacuum, the servers would melt after a few minutes.

Perhaps they meant to say "diabatic cooling system". A diabatic system is one that gets rid of heat (or draws in heat). Of course that's also the definition of "cooling", so if that's what they meant, it's a snobbish way of saying "cooling cooling system". With the a prefix, it's "non-cooling cooling system", which is gibberish. Unless of course by "abiatic (non-cooling) cooling system", they mean "cooling system that doesn't col, one that doesn't work". If on 100F days they are relying on a abiatic aka non-cooling aka broken cooling system, I don't think I want my servers there. I had a taste of that when I had servers at Alphared.

## Comment 100+F or 38+C typical annual high (Score 3, Informative)62

In Portland, it's reasonably cool MOST OF THE TIME.
Temperatures reach or exceed 90 F (32 C) on 14 days per year and reach or exceed 100 F (38 C) on 1.4 days per year on average.

I'm thinking this project will last about 350 days.

## Comment edit error. 30MPH = 900 units (Score 1)442

I edited my post from 25 to 30 MPH, but didn't edit the square. 30 would of course be 900 units in that example.

## Comment The opposite. Velocity squared, la weather systems (Score 3, Insightful)442

> the minimum output of variable sources like wind. If you have enough turbines the wind is always blowing somewhere, and the overall output of the entire fleet never drops below some predictable level.

Not at all true, but it doesn't need to be.
The energy in a fluid , such as air / wind, is proportional to the velocity SQUARED. In other words, if a 10 MPH wind has 100 units of energy, a 30 MPH wind has 625 units. A light breeze of 5 MPH, just 25 units. 40 MPH, 1600 units.

So suppose you build a turbine with a design speed of 25 MPH (625 units). You don't want it to fall apart in higher winds, so the blades, bearings etc need to be big and heavy enough to handle over 1,000 units. That means you'll have friction and other losses of about 25 units. Notice the loss is the same as 5 MPH of wind - you get zero energy production at 5 MPH. At 10 MPH, energy output is negligible. At much above the design speed, the force on the structure quickly becomes much higher than the 625 it's designed for, so the blades are rotated and such to work AGAINST the wind, to avoid having the turbine tower blown over or spin apart. These facts combine to mean turbines produce a useful amount of power only within a narrow range of wind speeds. Unfortunately, the rule power = velocity squared is a fundamental fact of physics. You can't change that by inventing a new type of battery chemistry or something.

If you look at a radar map of the US, you'll see one or two weather systems covering nearly a million square miles moving across the country. Missouri may be on the north end of a system while the southern wind of the system is in central Texas. That's pretty typical that the radar will show one or two systems for the whole country. So it's simply not true that the country as a whole always has "average" weather, that the wind is always 25 over much of the country. The fact is, a windy system will move across the country one week, then the next week heat wave will tour the country.

If you wanted to use wind as your "stable" primary energy source, you'd need a week of storage.

Fortunately not all energy needs to be a stable primary supply. If wind produces good power 10% of the time, you can reduce the use of natural gas generators 10% of the time. That's a good thing! If solar heating heats just your hot water, just 30% of the time, that's a lot of natural gas that doesn't need to be burned.

Since they are often idealists, it's not surprising that advocates of renewable energy always have their eye on renewables as a complete replacement for primary electrical generation, but it's sad because it means we've almost completely missed some great opportunities to make a big difference. Th syn is REALLY good at heating things up. If you've left water in your garden hose in the summer, you know making an effective solar water heater is dead simple - so simple most of us have done it on accident. Yet, most of us heat our water by burning fossil fuels. Why? Because we've ignored the obvious, simple, effective wins as we focus on the holy grail. We've spent tens of billions of dollars on solar electric and a workable solution is always five years and two billion dollars away. For half that money, we could have converted all homes to solar water heating AND mostly solved world hunger with the billions left over.

## Comment Trademark. Anyone can call their browser IE (Score 1)426

The name Firefox was chosen specifically to avoid describing the product, because a descriptive name like Internet Explorer or Office cane be trademarked, thereby meaning anyone can make a browser and call it Internet Explorer, or Browser.

There was another browser before Microsoft's that was called Internet Explorer. When the guy who made the original Internet Explorer sued for copyright infringement, Microsoft pointed out that's just a description, not a protectable name. I don't recall if the judge agreed in that particular case, but certainly we have Star Office, Open Office, etc. - there's nothing preventing other companies from selling office software called Office, so in that regard. Microsoft chose a terrible name - it's a name Apple can use too, selling a competing application suite.

If you've ever wondered why cars have such weird names, mainly being named after animals and other random shit, that's why. Chevrolet can't sell a sports car and call Mustang, because where cars are concerned, Mustang means Ford. Had Ford used the name Power rather than Mustang, every other car company could also call their muscle car a Power.

## Comment file handles aren't chrooted (Score 1)166

There are several ways. Some use the fact that file handles aren't chrooted. You can, for example, call fchdir() with handle inside the chroot, then chdir(..) several times. If the wrapper changed the working directory of the process before chroot, the escape code needs to fchdir to a directory other than the chroot root, so it'll mkdir first.

There IS some level of inconvenience to escaping chroot, so there is a degree of security against an unsophisticated attack. I guess it could be compared to locking a window - that'll make the window less convenient to open, but simply throwing a rock at it will do the trick.

## Comment I just did it, 2 ways. Click Drive. Drive == docs (Score 1)68

Have you tried that recently? I just did it on my wife's Chromebook two different ways. It's slightly EASIER than with a regular computer. I didn't try a third way that should also work.

The file picker dialog has two main folders, called Drive and Downloads. Google Docs has been merged with Google Drive, so tat icon labeled Drive is her Google Docs. I just tried that and it works. One could also do what you'd do on a regular computer - download from Drive and upload via the browser.

If she had Dropbox installed, that would also appear as a folder I think. But really the extremely easy way is to click "Upload" then choose "Drive".

## Comment chroot is for cross-compiling, not security (Score 1)166

It's trivial to step out of chroot. Chroot was not designed for security. It's very similar to cd and getting out basically consists of making a symlink and doing cd. Chroot is for cross-compiling, installing grub, etc. - changing the DEFAULT. value of / that your session uses.

AMD's virtualization is much more appropriate for security, as it's designed to make it such that a guest can't even KNOW whether it's a guest or not, much less escape and access the host system.

# Slashdot Top Deals

A right is not what someone gives you; it's what no one can take from you. -- Ramsey Clark

Working...