'The open source movement (Down people! It's just an umbrella term, not an excuse to rage about the nuaned differences in licensing) recognized early on that the only way to create reasonably secure code is to publish it and let anyone look at it. '
To make the claim that linux has been never been intentionally weakened in security, you need to know that every single security vulnerability in Linux (to take one example) was due to carelessness, not intended action.
Certainly - some classes of backdoor are trivially obvious 'if(sourceip==NSA)' - but others can be subtle logic errors.
To expand - and put this more in the context of a mobile phone class device say.
Why open-source software works is: Widely available repository of code. Many people able to review it, or sections of it, and understand it. Ease of submitting tested patches.
Hardware has problems that don't really fit well with this. The open schematic is the trivially easy part, and not really a problem. (though in practice, you need a schematic with copious links to design documents, which isn't well solved by open tools).
The number of people who can review it is rather smaller - as you can't open up a c file, and see a clear error or awkwardness in code that can be edited.
For all but the most basic errors, you are going to have to sit down and read several hundred pages of hardware documentation about how the chips in question work, in addition to having in-depth knowledge about the circuit design, and costings of likely changes.
Now, you've done this, and generated a patch that you think (for example) lowers the supply current by 1%.
Compile - test. On a PC, this takes a couple of minutes.
For something of a smartphone class, a one-off PCB may cost several hundred dollars. Then the parts will cost another several hundred dollars in small quantities, as well as being difficult to obtain. Now, you have to solder the parts onto the board, which is a decidedly nontrivial thing - and if you decide you want someone else to do this, it's probably another several hundred dollars.
So, you're at the thick end of a thousand dollars for a 'compile'.
Now, you boot the device, and it exhibits random hangs.
Neglecting the fact that you are going to need several hundred to several thousand dollars of test equipment, you now have to find the bug.
Is it: A) The fact that unlabled 0.5*1mm component C38 is in fact 20% over the designed value, as the assembly company put the wrong one in. B) C38 has a tiny bridge of solder underneath it that is making intermittent contact. C) The chipmaker for the main chip hasn't noticed that their chip doesn't quite do what they say it will do, and the datasheet is wrong. D) You missed a tangential reference on page 384 of the datasheet to proper setup of the RAM chip, and it is pure coincidence that all models up till now have booted. E) Because you're ordering small quantities, you had to resort to getting the chips from a distributor who diddn't watch their supply chain really carefully, and your main chip has in fact been desoldered from a broken cellphone. F) Though the design of the circuit is correct, and the board you made matches that design, and all the parts are correct and work properly, the inherent undesired elements introduced by real life physics means it doesn't work. G) A completely random failure of a part that could occur with even the best design, and best manufacture.
G - may mean that it's worthwhile making two or more of each revision - which of course boosts costs.
Hardware is nasty.
This gets a lot less painful of course for lower end hardware. For very limited circuits, which can be done on simple inexpensive PCBs, and be easily soldered at home - costs of a 'compile' can be in the tens of dollars, or even lower.
The new site has in fact been worked on in the background for several years, ever since a particular incident where a temporary redesign caused lawyers to get in touch and put it back to normal. After long negotiations, the company saw that slashdot was a suitable platform for their outreach beyond their core audience.
They are in fact changing the comments system to 'Comments are Magic' - and slashdot will henceforth be known as 'My Little Slashy'.
That's not quite the point. The two random devices are there not to be alternate sources of randomness, but to be a good source of provably random numbers gained from hardware randomness mixed into the entropy pool, and another source of cryptographically random numbers seeded from the first - but with perhaps orders of magnitude less entropy per output bit compared to input bits. The first source will stop outputting when it runs low on entropy.
Carbon emissions do not make you happy. In order to light to contemporary standards a home would take several tons of wax candles. Even conventional light-bulbs are _way_ more efficient. LED ones enormously so.
My new (larger) monitor that uses half the power my old one did is not in any way inferior.
A well insulated and designed home that uses less power to heat or cool is not any less livable.
Some devices may actually have negative carbon emissions.
Consider the Ipad (or nexus 7, or...). They will use several (3 or 4) watts viewing video or surfing the web. If they displace (by the owners choice) the use of a 'conventional' computer or TV - especially if it's an older one - they can come out strongly negative in total.
For a 55" screen - the reason is clear - if you're sitting fairly close to it - the edges are noticably further away from you. For a 5.5" screen - the most obvious reason would be to protect the screen. If, instead of a flat phone, you have one with a light curve on it - it will somewhat protect the screen from scratches due to laying it down wrong. I could also see that certain ways of holding it it would make long swipes easier. (With the thumb only)
Swallowing capsules containing a terabyte (about 12mm in diameter, and 15mm long of microSDs) is quite plausible. You can easily swallow a hundred of these, and it'll come out over the next 2 days. 100TB/2 days = 600 megabytes a second.
To be fair - this is in some ways a much, much easier task than navigating through a building. The rocket does not have to navigate in a more advanced way that remembering one point, and doing a simple manouever. Sure - the propulsive hardware is about eleven million times harder - but the navigation aspects could be implemented on an arduino, without straining it.
This isn't a GPL thing. This is a general IP thing.
If you are not - as a buisness selling software (even if in embedded hardware) requiring your suppliers to state that all software used is compliant with relevant licences, with appropriate penalty clauses or indemnification if they are not - then your lawyers don't deserve to be employed.
Exactly the same happens if you ship unlicenced windows on your systems.
'A german court thinks so'? Under very few legal codes is it OK to distribute something that you do not have the appropriate copyright/licence. Even if you don't investigate properly to find out if you do or don't, that doesn't get you off the hook. It may alter the penalties, but the fundamental legality isn't really in question, pretty much anywhere.
Raising 'GPL' is a red-herring here - 'Oh - I diddn't realise that machine had an unlicenced copy of windows on it' - is exactly the same case.
The 'walls' were thin sheets of metal - yes - this is an interesting breakthrough, but will not help much for thick walls. The effect is strongly frequency dependant, and relies on tuned membranes. It will not work for signals such as voice.
Or at least - it will not work as well as it would for tuned signals. It is unclear if you can get a useful effect with a large number (say 50) of tuned membranes covering the voice band. You can perhaps also do interesting novel things with tuning, if this is possible. You can have a 'transparent' wall - that mutes certain tones - for example if you want to notch out a train whistle that goes past every day.
Audio prisms are another application that springs to mind.
On closer reading, I find that it does indicate she fabricated the capacitor - which is noteworthy, and an achievement for someone of her age - but unless she has achieved actual breakthroughs in the field, this is again not nearly as newsworthy as the headline suggests.
Quite. Supercapacitors have been around for a couple of decades, getting a lot cheaper recently. Tens, or hundreds of millions of dollars have been spent on their development. At the moment, they lag _considerably_ behind cellphone batteries in terms of energy storage per unit volume, and cost.
Sure, you can make a supercapacitor battery for your phone and it will charge in 10s. But it may only run the phone for several minutes.
The above article gives absolutely no information whatsoever that indicates the student in question has overcome this barrier, which is absolutely key. Otherwise, this is just a 'student invents flying car' - when the proof given is a balloon tied to a toy car.
A very cynical person might say that the reason for the award was in the photo.
I am not saying that the student has not done work beyond simply sticking a $7 capacitor in a box with an LED, but that is all the article can lead one to guess.
Apart from the obligatory xkcd, the only way to simulate the brain is at a relatively high level.
You can use really, really detailed simulations of tiny parts - detailed simulations of neurons and their parts, synapses and the various signalling molecules to derive a higher level model. This higher level model does not need to be perfect - it only has to be as accurate and repeatable as the natural variation between neurons under various conditions. For example, we accept that both 7 year olds, drunk people, and people in early stage dementia are sentient - yet the properties of their neurons differ markedly.
If this brain is not to be somehow scanned from a real brain (which seems questionable, even from a technological point of view - the arrangement of the neurons does not tell you everything, you also need the strengths of their interconnections at each interconnection.) you are basically going to end up with a blank slate.
This will need basically teaching - from early development in the womb to adult state in a virtual environment. There has been fascinating work done that even if shown and moved around the same way as other animals are, if the animal is not in control of movement - it doesn't get any understanding of the world.
'It's the extended mission (to 2016) that may be cut short. The primary mission is already over, in 2012' - this is true, and somewhat false.
One of the things that was discovered early on was that the sun was not a sun-like star. It is unusually quiet - with little variation in brightness. Most of the population of stars observed by Kepler turn out to be lots noisier. This unfortunately made the primary mission - which was to detect earth like planets in earth like orbits - not achievable in the original timescale.
With an extended mission, you can dig through more data, and get enough signal from multiple planet crossings to bring it up out of the noise, getting you back to where you would have been had the original mission assumptions been correct. Unfortunately, the wheel failure seems to have constrained this. At best the degraded pointing mode they may end up in will have much more noise in the signal, making it much less useful for many purposes. (It will likely still be able to detect very large far out planets)
Another unfortunate fact is that the data from the cameras is very 'cooked' onboard - most of the data is thrown away automatically. This would make doing clever things to fix the problem in software on the returned data hard. How flexible the on-craft pipeline is is an interesting question.
A quick google reveals that phosphorus is about 1/10th of the total mass of DNA. Or, for an 80Mbase pair genome, about 160M atoms of phosphorus per cell. Randomly assuming the cells are 10um in size, and cubic leads to a volume of 10^-15m^3, or a mass of 10^-15 tons ish. 10^-9 grams. Working out the mass of potassium in DNA comes out to 10^-15 grams.
Or around one ppm, perhaps 20 if considering only dry matter.
This would seem to indicate my initial thought it might be due to elemental phosphorous deficiency making DNA manufacture unreasonably expensive in a potassium constrained environment unlikely. Nitrogen?
this presumes that the algorithms of the task in question are tractable, and in the brain in a aensible order.
in the cases of some tasks, it's looking like that's not really true. There is a sea of randomly interconnected neurons that get wired together by correlated inputs into the random sea.
These neurons learn they are associated, and wire together.
This may not lead to an extractable algorithm. I_highly_ recommend the brain science podcast.
It's not possible. Radio waves go both ways. If the signal from the real transmitter reaches the location of your jammer, the signal from your jammer reaches outside.
Slashdot Mirror
Unless your industry has lobbyists.
How many children does the alcohol or tobacco industry kill every year?
'The open source movement (Down people! It's just an umbrella term, not an excuse to rage about the nuaned differences in licensing) recognized early on that the only way to create reasonably secure code is to publish it and let anyone look at it. '
To make the claim that linux has been never been intentionally weakened in security, you need to know that every single security vulnerability in Linux (to take one example) was due to carelessness, not intended action.
Certainly - some classes of backdoor are trivially obvious 'if(sourceip==NSA)' - but others can be subtle logic errors.
Mine pluto!
To expand - and put this more in the context of a mobile phone class device say.
Why open-source software works is:
Widely available repository of code.
Many people able to review it, or sections of it, and understand it.
Ease of submitting tested patches.
Hardware has problems that don't really fit well with this.
The open schematic is the trivially easy part, and not really a problem.
(though in practice, you need a schematic with copious links to design documents, which isn't well solved by open tools).
The number of people who can review it is rather smaller - as you can't
open up a c file, and see a clear error or awkwardness in code that can be edited.
For all but the most basic errors, you are going to have to sit down and
read several hundred pages of hardware documentation about how the chips in question work, in addition to having in-depth knowledge about the circuit design, and costings of likely changes.
Now, you've done this, and generated a patch that you think (for example) lowers the supply current by 1%.
Compile - test.
On a PC, this takes a couple of minutes.
For something of a smartphone class, a one-off PCB may cost several hundred dollars. Then the parts will cost another several hundred dollars in small quantities, as well as being difficult to obtain.
Now, you have to solder the parts onto the board, which is a decidedly nontrivial thing - and if you decide you want someone else to do this, it's probably another several hundred dollars.
So, you're at the thick end of a thousand dollars for a 'compile'.
Now, you boot the device, and it exhibits random hangs.
Neglecting the fact that you are going to need several hundred to several thousand dollars of test equipment, you now have to find
the bug.
Is it:
A) The fact that unlabled 0.5*1mm component C38 is in fact 20% over the designed value, as the assembly company put the wrong one in.
B) C38 has a tiny bridge of solder underneath it that is making intermittent contact.
C) The chipmaker for the main chip hasn't noticed that their chip doesn't quite do what they say it will do, and the datasheet is wrong.
D) You missed a tangential reference on page 384 of the datasheet to proper setup of the RAM chip, and it is pure coincidence that all models up till now have booted.
E) Because you're ordering small quantities, you had to resort to getting the chips from a distributor who diddn't watch their supply chain really carefully, and your main chip has in fact been desoldered from a broken cellphone.
F) Though the design of the circuit is correct, and the board you made matches that design, and all the parts are correct and work properly, the inherent undesired elements introduced by real life physics means it doesn't work.
G) A completely random failure of a part that could occur with even the best design, and best manufacture.
G - may mean that it's worthwhile making two or more of each revision - which of course boosts costs.
Hardware is nasty.
This gets a lot less painful of course for lower end hardware. For very limited circuits, which can be done on simple inexpensive PCBs, and be easily soldered at home - costs of a 'compile' can be in the tens of dollars, or even lower.
The new site has in fact been worked on in the background for several years, ever since a particular incident where a temporary redesign caused lawyers to get in touch and put it back to normal.
After long negotiations, the company saw that slashdot was a suitable platform for their outreach beyond their core audience.
They are in fact changing the comments system to 'Comments are Magic' - and slashdot will henceforth be known as 'My Little Slashy'.
That's not quite the point.
The two random devices are there not to be alternate sources of randomness, but to be a good source of provably random numbers gained from hardware randomness mixed into the entropy pool, and another source of cryptographically random numbers seeded from the first - but with perhaps orders of magnitude less entropy per output bit compared to input bits.
The first source will stop outputting when it runs low on entropy.
Carbon emissions do not make you happy.
In order to light to contemporary standards a home would take several tons of wax candles.
Even conventional light-bulbs are _way_ more efficient. LED ones enormously so.
My new (larger) monitor that uses half the power my old one did is not in any way inferior.
A well insulated and designed home that uses less power to heat or cool is not any less livable.
Some devices may actually have negative carbon emissions.
Consider the Ipad (or nexus 7, or ...).
They will use several (3 or 4) watts viewing video or surfing the web.
If they displace (by the owners choice) the use of a 'conventional' computer or TV - especially if it's an older one - they can come out strongly negative in total.
It curves around your moobs.
For a 55" screen - the reason is clear - if you're sitting fairly close to it - the edges are noticably further away from you.
For a 5.5" screen - the most obvious reason would be to protect the screen.
If, instead of a flat phone, you have one with a light curve on it - it will somewhat protect the screen from scratches due to laying it down wrong.
I could also see that certain ways of holding it it would make long swipes easier.
(With the thumb only)
Actually check the iplayer, and watch new epsisodes.
Swallowing capsules containing a terabyte (about 12mm in diameter, and 15mm long of microSDs) is quite plausible.
You can easily swallow a hundred of these, and it'll come out over the next 2 days.
100TB/2 days = 600 megabytes a second.
It's well known that they do this sort of stuff - not regularly sweeping it out to a bank account is a really bad idea.
Sarbones-oxley - and similar laws can mean that you are required to log buisness transactions.
To be fair - this is in some ways a much, much easier task than navigating through a building.
The rocket does not have to navigate in a more advanced way that remembering one point, and doing a simple manouever.
Sure - the propulsive hardware is about eleven million times harder - but the navigation aspects could be implemented on an arduino, without straining it.
They provide you the means of complying with the licence though - it's just that it involves actual cash, rather than required actions.
This isn't a GPL thing.
This is a general IP thing.
If you are not - as a buisness selling software (even if in embedded hardware) requiring your suppliers to state that all software used is compliant with relevant licences, with appropriate penalty clauses or indemnification if they are not - then your lawyers don't deserve to be employed.
Exactly the same happens if you ship unlicenced windows on your systems.
'A german court thinks so'?
Under very few legal codes is it OK to distribute something that you do not have the appropriate copyright/licence.
Even if you don't investigate properly to find out if you do or don't, that doesn't get you off the hook.
It may alter the penalties, but the fundamental legality isn't really in question, pretty much anywhere.
Raising 'GPL' is a red-herring here - 'Oh - I diddn't realise that machine had an unlicenced copy of windows on it' - is exactly the same case.
The 'walls' were thin sheets of metal - yes - this is an interesting breakthrough, but will not help much for thick walls.
The effect is strongly frequency dependant, and relies on tuned membranes.
It will not work for signals such as voice.
Or at least - it will not work as well as it would for tuned signals.
It is unclear if you can get a useful effect with a large number (say 50) of tuned membranes covering the voice band.
You can perhaps also do interesting novel things with tuning, if this is possible.
You can have a 'transparent' wall - that mutes certain tones - for example if you want to notch out a train whistle that goes past every day.
Audio prisms are another application that springs to mind.
On closer reading, I find that it does indicate she fabricated the capacitor - which is noteworthy, and an achievement for someone of her age - but unless she has achieved actual breakthroughs in the field, this is again not nearly as newsworthy as the headline suggests.
Quite.
Supercapacitors have been around for a couple of decades, getting a lot cheaper recently.
Tens, or hundreds of millions of dollars have been spent on their development.
At the moment, they lag _considerably_ behind cellphone batteries in terms of energy storage per unit volume, and cost.
Sure, you can make a supercapacitor battery for your phone and it will charge in 10s. But it may only run the phone for several minutes.
The above article gives absolutely no information whatsoever that indicates the student in question has overcome this barrier, which is absolutely key.
Otherwise, this is just a 'student invents flying car' - when the proof given is a balloon tied to a toy car.
A very cynical person might say that the reason for the award was in the photo.
I am not saying that the student has not done work beyond simply sticking a $7 capacitor in a box with an LED, but that is all the article can lead one to guess.
http://xkcd.com/876/
Apart from the obligatory xkcd, the only way to simulate the brain is at a relatively high level.
You can use really, really detailed simulations of tiny parts - detailed simulations of neurons and their parts, synapses and the various signalling molecules to derive a higher level model.
This higher level model does not need to be perfect - it only has to be as accurate and repeatable as the natural variation between neurons under various conditions.
For example, we accept that both 7 year olds, drunk people, and people in early stage dementia are sentient - yet the properties of their neurons differ markedly.
If this brain is not to be somehow scanned from a real brain (which seems questionable, even from a technological point of view - the arrangement of the neurons does not tell you everything, you also need the strengths of their interconnections at each interconnection.) you are basically going to end up with a blank slate.
This will need basically teaching - from early development in the womb to adult state in a virtual environment.
There has been fascinating work done that even if shown and moved around the same way as other animals are, if the animal is not in control of movement - it doesn't get any understanding of the world.
I strongly recommend the brain science podcast.
http://brainsciencepodcast.com/bsp/neuroplasticity-a-review-of-its-discovery-bsp-10.html - is one episode on how the brain changes over time, in massive and significant ways, driven by practice and other factors.
'It's the extended mission (to 2016) that may be cut short. The primary mission is already over, in 2012' - this is true, and somewhat false.
One of the things that was discovered early on was that the sun was not a sun-like star.
It is unusually quiet - with little variation in brightness. Most of the population of stars observed by Kepler turn out to be lots noisier.
This unfortunately made the primary mission - which was to detect earth like planets in earth like orbits - not achievable in the original timescale.
With an extended mission, you can dig through more data, and get enough signal from multiple planet crossings to bring it up out of the noise, getting you back to where you would have been had the original mission assumptions been correct.
Unfortunately, the wheel failure seems to have constrained this.
At best the degraded pointing mode they may end up in will have much more noise in the signal, making it much less useful for many purposes.
(It will likely still be able to detect very large far out planets)
Another unfortunate fact is that the data from the cameras is very 'cooked' onboard - most of the data is thrown away automatically. This would make doing clever things to fix the problem in software on the returned data hard. How flexible the on-craft pipeline is is an interesting question.
A quick google reveals that phosphorus is about 1/10th of the total mass of DNA.
Or, for an 80Mbase pair genome, about 160M atoms of phosphorus per cell.
Randomly assuming the cells are 10um in size, and cubic leads to a volume of 10^-15m^3, or a mass of 10^-15 tons ish.
10^-9 grams.
Working out the mass of potassium in DNA comes out to 10^-15 grams.
Or around one ppm, perhaps 20 if considering only dry matter.
This would seem to indicate my initial thought it might be due to elemental phosphorous deficiency making DNA manufacture unreasonably expensive in a potassium constrained environment unlikely.
Nitrogen?
this presumes that the algorithms of the task in question are tractable, and in the brain in a aensible order.
in the cases of some tasks, it's looking like that's not really true. There is a sea of randomly interconnected neurons that get wired together by correlated inputs into the random sea.
These neurons learn they are associated, and wire together.
This may not lead to an extractable algorithm.
I_highly_ recommend the brain science podcast.
http://brainsciencpodcast.wordpress.com/2007/11/16/brain-science-podcast-24-reading-and-the-brain/
This is a highly accessible discussion of various topics in neuroscience.
It's not possible.
Radio waves go both ways.
If the signal from the real transmitter reaches the location of your jammer, the signal from your jammer reaches outside.