Thermocouples are generally made out of non-novel materials because they don't need to be efficient. (In fact, any pair of dissimilar metals joined correctly will form a thermocouple, but some are better suited than others.)
...the TSA has awarded an indefinite delivery / indefinite quantity (IDIQ) contract, worth up to $245 Million...
Headline says "spending" $245 million. An IDIQ contract is not at all the same as spending -- it is a vehicle through which money *can* be spent. TSA could use it to purchase between $0 and and $245 million in scanners. It doesn't even mean that there's money allocated in their budget for this.
As previously reported, Jonathan Corbett proved that TSA's current nude-o-scopes are incapable of actually detecting hidden objects.
No, he demonstrated that it is possible to conceal an object from the scanners. There are still plenty of hidden objects (in practice, most) that they can detect, so they are capable of actually detecting hidden objects. Just not all of them.
If you're going to be inflammatory, at least get your facts half-right.
We can see that temperatures are cyclical, but on which side of the slope are we?
It doesn't really matter, since the cyclical changes are, at their fastest rates, an order of magnitude slower than the recent changes described as "global warming".
This is actually one of the fundamental observations that led to relativity (and why the speed of light is the fastest information or energy can travel).
Light moves away from you at exactly the speed of light, regardless of what your velocity is. If you're travelling at 0.99c (relative to a "stationary" observer) and you shine a light forward, it looks like it's moving at speed c away from you. Shine a light backwards, looks like it's moving speed c away from you. To the stationary observer, both beams of light *also* look like they're travelling at exactly speed c (and you look like you're travelling at 0.99c). So the stationary observer's perception of how you and the beams of light are moving relative to one another is different from your perception of the same thing. (However, both are equally valid.)
Also, realize that that is the only reason for all Apple proprietary connectors. So you can't easily switch to a competitors device.
People are going to balk at switching to another device because of the power/data cable that comes free with every device? It's more of a hassle to transfer your contacts.
You didn't know what I was referring to, so you went and found something, assumed that's what I was referring to, and then criticized me for that thing not being relevant? I hope you see the error in logic here.
No shit. They don't have magic spy software on their own laptops that can provide absolute proof. How's someone at the FBI going to determine, without a doubt, that none of the laptops the FBI uses was hacked? How are they going to determine that absolutely zero agents requested or managed to get their hands on the information being discussed? They can't.
So, while they're using weasel words, it's also the correct way to respond: They can't be absolutely sure of their statement, but they have no evidence that would lead them to believe otherwise.
I imagine a sufficiently clever hacker could think of a way to bypass the guest OS and the hypervisor and do wacky things,
Can and has. The sufficiently clever hacker that has been behind most incidences of piercing the guest-hypervisor veil is one Joanna Rutkowska, CEO of Invisible Things Lab.
Sorry, I was unclear -- I agree with you. You should *keep* *every single* zero-length file. They take up virtually no space (only space for the file metadata) and are usually important.
For this purpose, there's really no point in using CRC32 at all. The disk-access cost so far outweighs any computational cost (at least on this guy's hardware) that you might as well use SHA-512.
As you mention, CRC32 has much too high a chance of collision. MD5 has essentially no chance of collision unless files are specifically designed that way. But since you have plenty of free computational time, you might as well use SHA-512, since it has the smallest chance of an accidental collision and no known way of creating intentional collisions.
b) Looking at the first few bytes of files with the same size.
Note that there's no reason to only look at the first few bytes. On spinning disks, any read smaller than about 16K will take the same amount of time. Comparing two 16K chunks takes zero time compared to how long it takes to read them from disk.
You could, for that matter, make it a 3-pass system that's pretty fast: a) get all file sizes; remove all files that have unique sizes b) compute the MD5 hash of the first 16K of each file; remove all files that have unique (size, header-hash) pairs c) compute the MD5 hash of the whole file; remove all files that have unique (size, hash) pairs
Now you have a list of duplicates.
Don't forget to eliminate all files of zero length in step (a). They're trivially duplicates but shouldn't be deduplicated.
Because when a person is arrested for a crime, it's the duty of law enforcement to collect and examine available evidence that could support or refute the theory that the person committed the crime. An iPhone can contain a lot of useful evidence. (My favorite is a text message to a girlfriend: "Hold on, I'm about to go rob the Dunkin Donuts.")
Have they not spoken with the hackers that discovered Jailbreaking? They are well known and can be reached rather easily.
Pretty much all of the tools that extract data from iPhones (and there are many) are based directly off of the techniques used by jailbreakers. People in the field know this. The problem is that these techniques are not particularly reliable when used to pull data off of a properly-secured phone. Sure, they work just fine in the context of jailbreaking, where you have the assistance of the owner of the phone (who can arbitrarily change its settings to be more amenable to jailbreaking). They are not particularly reliable in the context of forensics.
I can't help but wonder the purpose of a DOJ statement like his being made public.
It was a higher-up in the DoJ (specifically, Ovie Carroll) discussing challenges in digital forensics (at a conference on digital forensics). It was a brief mention in a larger talk and a fact that does not surprise anyone in the field. It's well-known that pulling data off of an iPhone can be a real pain in the ass. (IMO, I would consider Android worse, as there is not yet a reliable technique that can pull data off of an unrooted phone without modifying the phone's data, and data modification -- even when justified and documented -- is a big problem in some jurisdictions.)
There is a problem when the definition of 'climatologist' is effectively 'someone who studies the effects of AGW and recommends policy to mitigate it'.
There would be, but that's not the definition of a climatologist. It's also not the selection criteria to be a peer reviewer for a climatology journal. (And, for that matter, climatology journals are not the only places to publish peer-reviewed climatology papers.) It's just what you imagine the selection criteria to be, which is very different.
I really doubt anything useful can be taken from such a model
It's a real shame we don't have a systematic way of investigating the accuracy of a model and are forced to rely on the gut feelings (I mean, doubts) of random people on the Internet.
Regardless of one's opinion on the Wall Street Journal...
This is a WSJ Online article in the Opinion section. So, it's one of many blogs, essentially, under the WSJ name. The standards for the real Wall Street Journal and for their online-only content (particularly the Opinion section) are dramatically different. The online-only content is absolutely terrible.
Slashdot Mirror
No, you only need to remove it with a suction cup if you want the thing to stay in one piece. Not a problem if it's already broken.
Thermocouples are generally made out of non-novel materials because they don't need to be efficient. (In fact, any pair of dissimilar metals joined correctly will form a thermocouple, but some are better suited than others.)
...the TSA has awarded an indefinite delivery / indefinite quantity (IDIQ) contract, worth up to $245 Million...
Headline says "spending" $245 million. An IDIQ contract is not at all the same as spending -- it is a vehicle through which money *can* be spent. TSA could use it to purchase between $0 and and $245 million in scanners. It doesn't even mean that there's money allocated in their budget for this.
As previously reported, Jonathan Corbett proved that TSA's current nude-o-scopes are incapable of actually detecting hidden objects.
No, he demonstrated that it is possible to conceal an object from the scanners. There are still plenty of hidden objects (in practice, most) that they can detect, so they are capable of actually detecting hidden objects. Just not all of them.
If you're going to be inflammatory, at least get your facts half-right.
We can see that temperatures are cyclical, but on which side of the slope are we?
It doesn't really matter, since the cyclical changes are, at their fastest rates, an order of magnitude slower than the recent changes described as "global warming".
This is actually one of the fundamental observations that led to relativity (and why the speed of light is the fastest information or energy can travel).
Light moves away from you at exactly the speed of light, regardless of what your velocity is. If you're travelling at 0.99c (relative to a "stationary" observer) and you shine a light forward, it looks like it's moving at speed c away from you. Shine a light backwards, looks like it's moving speed c away from you. To the stationary observer, both beams of light *also* look like they're travelling at exactly speed c (and you look like you're travelling at 0.99c). So the stationary observer's perception of how you and the beams of light are moving relative to one another is different from your perception of the same thing. (However, both are equally valid.)
Also, realize that that is the only reason for all Apple proprietary connectors. So you can't easily switch to a competitors device.
People are going to balk at switching to another device because of the power/data cable that comes free with every device? It's more of a hassle to transfer your contacts.
You didn't know what I was referring to, so you went and found something, assumed that's what I was referring to, and then criticized me for that thing not being relevant? I hope you see the error in logic here.
No shit. They don't have magic spy software on their own laptops that can provide absolute proof. How's someone at the FBI going to determine, without a doubt, that none of the laptops the FBI uses was hacked? How are they going to determine that absolutely zero agents requested or managed to get their hands on the information being discussed? They can't.
So, while they're using weasel words, it's also the correct way to respond: They can't be absolutely sure of their statement, but they have no evidence that would lead them to believe otherwise.
...finding the names of agents is pretty easy...
Yeah, especially when the agent stated his name in a well-known FBI PR video targeting hackers.
Really? Most schools don't have AC?
I imagine a sufficiently clever hacker could think of a way to bypass the guest OS and the hypervisor and do wacky things,
Can and has. The sufficiently clever hacker that has been behind most incidences of piercing the guest-hypervisor veil is one Joanna Rutkowska, CEO of Invisible Things Lab.
Interesting how that works, don't you think?
Sorry, I was unclear -- I agree with you. You should *keep* *every single* zero-length file. They take up virtually no space (only space for the file metadata) and are usually important.
For this purpose, there's really no point in using CRC32 at all. The disk-access cost so far outweighs any computational cost (at least on this guy's hardware) that you might as well use SHA-512.
As you mention, CRC32 has much too high a chance of collision. MD5 has essentially no chance of collision unless files are specifically designed that way. But since you have plenty of free computational time, you might as well use SHA-512, since it has the smallest chance of an accidental collision and no known way of creating intentional collisions.
Fortunately, you actually only need about 2^16 files to get collisions on a 32-bit CRC.
b) Looking at the first few bytes of files with the same size.
Note that there's no reason to only look at the first few bytes. On spinning disks, any read smaller than about 16K will take the same amount of time. Comparing two 16K chunks takes zero time compared to how long it takes to read them from disk.
You could, for that matter, make it a 3-pass system that's pretty fast:
a) get all file sizes; remove all files that have unique sizes
b) compute the MD5 hash of the first 16K of each file; remove all files that have unique (size, header-hash) pairs
c) compute the MD5 hash of the whole file; remove all files that have unique (size, hash) pairs
Now you have a list of duplicates.
Don't forget to eliminate all files of zero length in step (a). They're trivially duplicates but shouldn't be deduplicated.
on the moon
On Mars. On Mars. That's what I get for switching the order of Slashdot and coffee.
It just looked unprofessional to me.
They landed a robot on the moon. Maybe we should be taking tips on professional dress from them. It seems to have worked out.
Never view a stock graph with a linear axis.
they may not be available in your country
Is there another country with a Denver and a San Francisco?
Because when a person is arrested for a crime, it's the duty of law enforcement to collect and examine available evidence that could support or refute the theory that the person committed the crime. An iPhone can contain a lot of useful evidence. (My favorite is a text message to a girlfriend: "Hold on, I'm about to go rob the Dunkin Donuts.")
They changed the laws to allow the export of much stronger encryption. This was quite some time ago.
I know, it's weird that the government made the right decision, but it happened.
Have they not spoken with the hackers that discovered Jailbreaking? They are well known and can be reached rather easily.
Pretty much all of the tools that extract data from iPhones (and there are many) are based directly off of the techniques used by jailbreakers. People in the field know this. The problem is that these techniques are not particularly reliable when used to pull data off of a properly-secured phone. Sure, they work just fine in the context of jailbreaking, where you have the assistance of the owner of the phone (who can arbitrarily change its settings to be more amenable to jailbreaking). They are not particularly reliable in the context of forensics.
I can't help but wonder the purpose of a DOJ statement like his being made public.
It was a higher-up in the DoJ (specifically, Ovie Carroll) discussing challenges in digital forensics (at a conference on digital forensics). It was a brief mention in a larger talk and a fact that does not surprise anyone in the field. It's well-known that pulling data off of an iPhone can be a real pain in the ass. (IMO, I would consider Android worse, as there is not yet a reliable technique that can pull data off of an unrooted phone without modifying the phone's data, and data modification -- even when justified and documented -- is a big problem in some jurisdictions.)
There is a problem when the definition of 'climatologist' is effectively 'someone who studies the effects of AGW and recommends policy to mitigate it'.
There would be, but that's not the definition of a climatologist. It's also not the selection criteria to be a peer reviewer for a climatology journal. (And, for that matter, climatology journals are not the only places to publish peer-reviewed climatology papers.) It's just what you imagine the selection criteria to be, which is very different.
I really doubt anything useful can be taken from such a model
It's a real shame we don't have a systematic way of investigating the accuracy of a model and are forced to rely on the gut feelings (I mean, doubts) of random people on the Internet.
Regardless of one's opinion on the Wall Street Journal...
This is a WSJ Online article in the Opinion section. So, it's one of many blogs, essentially, under the WSJ name. The standards for the real Wall Street Journal and for their online-only content (particularly the Opinion section) are dramatically different. The online-only content is absolutely terrible.