There have been no hacks for the UK Sky system for many years. Since they last changed the encryption system several years ago, nobody has produced a working hack. So what makes you think that every system is inherantly hackable and has a hack already waiting to be released? It's obviously perfectly possible to make an uncrackable system as otherwise someone would have cracked it by now. Bollocks sir, pure bollocks.
Not exactly revolutionary... This is just list seeding.
You shove in one-time known fake name into a mailing list (postal or e-mail) that you sell and then if any mail arrives at that address sent by someone you didn't sell the list to, then you know that they've been abusing their terms for use of the list. I do the same thing with websites... I register for websites I write with sitename_seed@mydomain.com and if any of the 'seed' addresses get mail, then I know that someone's been harvesting addresses from that site. Thankfully this has never happened (yet!).
Yeah but on most OS's you can't change every single font size, and even if you can, it doesn't stop things like icons being tiny and webpages having hard-coded font sizes set in pixels.
I don't know what Linux is like, but Windows doesn't cope very well with very high resolutions. Try reading the text on BBC News with your monitor in 2048x1564 - it's almost impossible even on a fairly large 19" screen.
Isn't that called microfiche?! Can you actually read any text at that resolution?
> They also went back to the slower (though higher capacity) 4200rpm drive > (instead of the 5400rpm drive in the 5105).
How do you know it's slower? RPM doesn't equal speed unless every single other parameter is identical. It could be they've stored the data more densely so that this disc is actually faster than the old one but uses less power. The clue to this is that it's higher capacity. Usually higher capacity drives are faster than lower capacity drives of the same type.
You kind of missed my point - I'm not blaming Western Union, I'm blaming eBay for making it so incredibly easy to hijack an account. They should have their security as tight as online banking systems, but it's actually less secure than most public forum systems including this one!
Western Union is just a handy aide they use to almost anonymously get the cash -it's not actually a problem with Western Union - just a problem for the prosecutors and buyers who've lost their money and can't track who's got it.
This is the absolute least of the problems with eBay!
Unless eBay can sort out the massive amount of fraud [msnbc.com] that's going on right now then I'm never using it again.
There seems to be an absolutely massive problem at the moment with people hijacking eBay accounts and their associated e-mail addresses and eBay don't seem to want to anything about it.
Anyone who uses eBay and has a weak password on their e-mail account (or an obvious answer to their secret question) is vulnerable to having their eBay account taken over (complete with e-mail account and credit card details) and used by a Western Union scammer.
What's a Western Union scammer? Someone who asks to be paid though Western Union (who offer zero buyer protection or tracking of funds) and then simply never ships the item. Western Union seem happy to dish out funds to anyone so the fact that the account is in the wrong name doesn't seem to cause any problems.
eBay should make it so it's impossible to take over an account by changing the password/and/or e-mail address unless you know lots of personal information (D.O.B., mothers maiden name, etc etc).
I'm finding it very difficult to get eBay to reply or for any news agencies to give this any publicity.
Over the weekend I saw about 30 Sony plasma screens advertised (usually "pre-approved bidders only") - almost none of which were legitiate. When you contact the seller - you get a similar message every time - "The item will be shipped from and I would like you to pay though Western Union". They remove them eventually if you complain, but the point is, the fact that more are appearing means that they're still finding it very easy to hijack your account.
> Even "classic" mode is a bear, because the control panel is all munged up. Erg!
Well put the control panel into classic mode too then! Duh!...and the start menu too if you want. No-ones stopping you. You can make it almost identical to 2K if you want - it's quite easy (which is the whole point of Windows).
Unless eBay can sort out the massive amount of fraud that's going on right now then I'm never using it again anyway.
There seems to be an absolutely massive problem at the moment with people hijacking eBay accounts and their associated e-mail addresses and eBay don't seem to want to anything about it.
Anyone who uses eBay and has a weak password on their e-mail account (or an obvious answer to their secret question) is vulnerable to having their eBay account taken over (complete with e-mail account and credit card details) and used by a Western Union scammer.
What's a Western Union scammer? Someone who asks to be paid though Western Union (who offer zero buyer protection or tracking of funds) and then simply never ships the item. Western Union seem happy to dish out funds to anyone so the fact that the account is in the wrong name doesn't seem to cause any problems.
eBay should make it so it's impossible to take over an account by changing the password/and/or e-mail address unless you know lots of personal information (D.O.B., mothers maiden name, etc etc).
I'm finding it very difficult to get eBay to reply or for any news agencies to give this any publicity.
Over the weekend I saw about 30 Sony plasma screens advertised (usually "pre-approved bidders only") - almost none of which were legitiate. When you contact the seller - you get a similar message every time - "The item will be shipped from and I would like you to pay though Western Union". They remove them eventually if you complain, but the point is, the fact that more are appearing means that they're still finding it very easy to hijack your account.
You're right - I haven't actually tried, I was just repeating what I'd been told by our firewall supplier (who may or may not be particularly knowledgeable).
The other criteria which I forgot to mention is that we also need VPN support. Can a bridging firewall support VPNs when, it doesn't actually have an external facing IP of it's own? Presumably it would have to create a virtual IP address and use that for the VPN?
I don't really want to try building one myself using BSD, as then it would be my fault if it didn't work:)
While it's on topic, I've always wondered how many people use transparent firewalls. I work for a small web development company in the UK and as such we have about 30 IP which host a few public facing webservers as well as our mail and stuff. We decided to use a transparent firewall (ie, one that lets us keep our 30 real IP addresses on the machines which are public facing - rather than 192.x or 10.x addresses) so that if there were any problems with it, we could just remove it (physically) and everything would still work. No network reconfiguration required.
But it seems that it's quite uncommon for firewalls to even support this feature and even less common for people to actually use it in this mode. Is there a reason that more firewalls don't support this functionality, or are there good reasons not to configure your network like this?
A major problem we would have if we used something like a Cisco PIX is that we wouldn't be able to see the websites we are hosting. The domain would map to a normal internet facing address, yet we can't see those addresses from the LAN (they don't seem to apply the port mapping to connections that have come from the LAN - so we'd need to look at them on their internal IP or something).
How many people actually use transparent firewalls? Or how do you get round the problems above if you're a web hosting company and you don't have a transparent firewall? Do any decent firewalls (apart from Sonicwalls) actually support this?
OK, I probably didn't explain myself very well: A simple NAT firewall, such as that built into Windows XP and quite a few routers, will allow all outbound traffic by default. From the outside however, all ports that don't have an outbound connection will appear to be closed (as opposed to open, or non existant/stealth). "Closed" meaning that the computer actively sent back a packet saying that it doesn't accept connections on that port. Meanwhile, you can happily run games/P2P/ICQ etc without noticing that you're even behind a firewall - without SPI.
SPI works on another level - rather than forwarding connections, it actually analyses the raw packets and decides whether or not to forward them. It can even be set to be completely unresponsive on the ports that are not in use meaning that if no ports are open, there is no way to tell that there is a computer at that IP address. It can also do some clever stuff, like inspect the contents of packets and conditionally allow the traffic or perhaps open another port based on it's contents.
All I was trying to point out was that you don't need SPI to get the ease of use you were talking about.
Certainly some routers may require you to manually open outbound ports before something will work, but this isn't because they are (or aren't) SPI firewalls - it's more to do with the default configuration. Netgears allow all outbound traffic by default, but they could easily have been shipped to only allow HTTP, POP3 and IMAP4 by default, and block everything else.
The BEST feature of SPI firewalls is that *some* of them can be transparent. Meaning that if your firewall is protecting 30 machines, those machines can keep their real internet IP addresses and you just insert the firewall in the middle - no network reconfiguration required. eg, the Sonicwall Pro 230 does this. As far as I know, no NAT type firewalls can do this, meaning your internal servers all need to be moved to a private IP (eg 192.168.*.*) in order to work behind the firewall. If it breaks and needs to be removed, you need to either quickly replace it, or remove it and reconfire the IPs on every single machine behind the firewall.
The great thing about stateful packet inspection is that you don't have to configure it. If you want to play some new game that does multiplayer play on the Internet through some wacky port, it will just work
You're very confused. This behaviour is absolutely nothing to do with stateful packet inspection. *ALL* routers will behave like this if you enable routing of all outbound traffic - even really cheap and simple NAT firewalls (not really even a firewall). Allowing all outbound traffic means that any trojans you get though e-mail/floppy/open HTTP port etc etc mean that the trojans can phone home and start sending out personal information or attacking other systems. Hardly secure...
The particular Netgear firewall you mentionned (FM114P/FR114P) is one I've used at home. It's probably the least stable and most annoying piece of hardware I've ever used. If you read the forums on dslreports.com you'll see that most users are plagued with problems ranging from random lock ups (mine needs rebooting every couple of days) to it's inability to handle long URLs (causes lock ups) and it's susceptability to the common ping of death attack, which means anyone on the internet can lock up your router with a simple ping command. I've had most of these problems myself, and if you combine them with the poor performance (especially if WEP is enabled) and power supply problems, you end up with a pretty poor product where the only redeeming factor is it's price. I think Netgear have resolved a few of these issues with the latest firmware, but they should have got it to this stage BEFORE releasing it, not a year or two afterwards! Why it takes 12 minutes to copy a 100mb file across the network - when both machines are in line of sight with the router and have full signal strength is beyond me! That's only 135k/sec which is almost exactly 1Mbit - and it's supposed to be an 11Mbit network - not exactly fast!
You can't. And no-one's saying they will. They're talking about eBay themselves collecting the VAT - not the *sellers* on eBay! You never pay eBay for the items - you pay the seller. The seller then pays eBay a listings fee and this is what will be taxed - not the item.
The exception perhaps would be new goods, but that would be up to the selling vendor to ensure they charge people the appropriate tax for their region.
G is already a measurement of acceleration. Ie 1G = 9.80665m/s/s if my memory serves me correctly.
You can't damage something more by subjecting it to the same acceleration for less time! The only affect that would have, would be to leave the object at a lower speed - it has not been any more 'stressed' because the acceleration lasted less long.
If we're talking about something like metal fatigue, then the magnitude, combined with the frequency of oscillation of the accelleration, *might* then correlate to the *time* taken to break the metal concerned (but not necessarily the probability). But that's about as close as I can come to making sense of your post...
Measuring G per second is silly.. that means you're measuring in meters per second per second per second! A totally nonsensical measurement for anything!
It sounds like you made that up and you're not actually basing your hypothesis on any facts... I wish there was a "-1, Wrong" in the moderating list.
15G is nothing - that's like dropping the card onto carpet from about 2ft. Not exactly stressful for some solid state hardware - even a hard drive could probably cope with that while running. The duration doesn't make much difference - providing they don't exceed the amount of G required to break something (probably more like 80+G). The vibrations might cause the G level to peak much higher than the overall accelleration of the rocket however.
I would have thought that vibrations are much worse than the overall acceleration of the rocket; Anyone ever taken a computer out of the back of a car (which probably never exceeds 1.5G) only to find that some screws have come loose or a PCI card has fallen out? (cos I have!).
It's a television - not a monitor (hence the words "television" in the article and on the manual) but you can use it on a PC. 1024 is easily enough to view PAL TV (720x582 lines) or even the lower resolution American system (NTSC) which I think is effectively 640x480 maximum. No wonder TV looks fuzzy when you go to America - I hadn't realised there was such a difference until I checked the stats.
If you want a monitor, there are much higher resolution LCD displays available. It's only 21" but the Eizo L985EX is very well reviewed.
I didn't think there was any guarantee that with SA on, it would always average out to be zero over a certain unit of time? ie, can't they leave SA strayed in one direction for a very long amount of time and therefore mess up the results?
There aren't two types so to speak, but there are a number of options available if you need a more accurate fix.
First of all, all GPSs take a short while (10-300 seconds) to work out where they are when you first turn them on. How long it takes depends on a number of things:
How long it is since it was last switched on; More than a few hours and all the satellites will be in a different place, meaning the almanac (the orbital postitions of the satellites) will be out of date.
How far away from the previous location it is; again, if you go a few hundred miles when it's switched off, it'll try and lock to the same satellites it previously had a fix on, but if you're in a different place, these will have changed.
So turning it on for the first time in the last few weeks is bound to take a while - but that's the same for all GPS positions... it just takes time to download the new orbital position information from a satellite it can 'see', before it knows which ones it should be able to see and try and lock on to.
BUT, to increase the accuracy of GPS, many countries have also implemented a DGPS system (Differential GPS or other similar systems designed for use by aircraft on final approaches). This greatly increases the accuracy of a GPS receiver by letting it receive information from fixed base stations about the error imposed by environmental conditions, satellite mis-alignment or SA (Selective Availablity) and allows the unit to correct for these and maintain it's full accuracy to a very high level (perhaps a few centimeters instead of several feet). This system though, is pretty much useless in the context of the article as the base stations are going to be moving as well.
What I expect happens in this context is a GPS is left in a fixed position for a very long time and is therefore able to average out it's readings over a long period of time so that the errors are virtually eliminated. Because the land moves so slowly - it doesn't matter if it takes a really long time to get an accurate reading - and reading averaged over the period of several months is going to be really accurate (perhaps to centimeter level, or close to the resolution of the GPS).
None of this will work however, if the US switches SA back on (Selective Availability) which is an artificially imposed error designed primarily to prevent other nations from having access to a very reliable signal that could be used to build highly accurate GPS guided bombs. However, SA has been turned off for quite a while now and has only been turned on again (I think) during the Iraq conflict for security reasons. Allied military units can easily correct for this error, but other nations won't have the hardware or codes required to decrypt it.
There are a couple of new GPS systems due to come online soon that are going to be even more accurate than the existing US system. Hopefully this will be available to civilians worldwide and will mean that extra DGPS hardware isn't required for things like navigation close to cliffs and rocks.
Slashdot Mirror
There have been no hacks for the UK Sky system for many years. Since they last changed the encryption system several years ago, nobody has produced a working hack. So what makes you think that every system is inherantly hackable and has a hack already waiting to be released? It's obviously perfectly possible to make an uncrackable system as otherwise someone would have cracked it by now. Bollocks sir, pure bollocks.
Not exactly revolutionary... This is just list seeding.
You shove in one-time known fake name into a mailing list (postal or e-mail) that you sell and then if any mail arrives at that address sent by someone you didn't sell the list to, then you know that they've been abusing their terms for use of the list. I do the same thing with websites... I register for websites I write with sitename_seed@mydomain.com and if any of the 'seed' addresses get mail, then I know that someone's been harvesting addresses from that site. Thankfully this has never happened (yet!).
Yeah but on most OS's you can't change every single font size, and even if you can, it doesn't stop things like icons being tiny and webpages having hard-coded font sizes set in pixels.
I don't know what Linux is like, but Windows doesn't cope very well with very high resolutions. Try reading the text on BBC News with your monitor in 2048x1564 - it's almost impossible even on a fairly large 19" screen.
Nick...
> 15 inch display with 1600x1200 resolution
Isn't that called microfiche?! Can you actually read any text at that resolution?
> They also went back to the slower (though higher capacity) 4200rpm drive
> (instead of the 5400rpm drive in the 5105).
How do you know it's slower? RPM doesn't equal speed unless every single other parameter is identical. It could be they've stored the data more densely so that this disc is actually faster than the old one but uses less power. The clue to this is that it's higher capacity. Usually higher capacity drives are faster than lower capacity drives of the same type.
Nick...
You kind of missed my point - I'm not blaming Western Union, I'm blaming eBay for making it so incredibly easy to hijack an account. They should have their security as tight as online banking systems, but it's actually less secure than most public forum systems including this one!
Western Union is just a handy aide they use to almost anonymously get the cash -it's not actually a problem with Western Union - just a problem for the prosecutors and buyers who've lost their money and can't track who's got it.
Nick...
Oops - I missed out the link - see here for MSNBC coverage
This is the absolute least of the problems with eBay!
Unless eBay can sort out the massive amount of fraud [msnbc.com] that's going on right now then I'm never using it again.
There seems to be an absolutely massive problem at the moment with people hijacking eBay accounts and their associated e-mail addresses and eBay don't seem to want to anything about it.
Anyone who uses eBay and has a weak password on their e-mail account (or an obvious answer to their secret question) is vulnerable to having their eBay account taken over (complete with e-mail account and credit card details) and used by a Western Union scammer.
What's a Western Union scammer? Someone who asks to be paid though Western Union (who offer zero buyer protection or tracking of funds) and then simply never ships the item. Western Union seem happy to dish out funds to anyone so the fact that the account is in the wrong name doesn't seem to cause any problems.
eBay should make it so it's impossible to take over an account by changing the password/and/or e-mail address unless you know lots of personal information (D.O.B., mothers maiden name, etc etc).
I'm finding it very difficult to get eBay to reply or for any news agencies to give this any publicity.
Over the weekend I saw about 30 Sony plasma screens advertised (usually "pre-approved bidders only") - almost none of which were legitiate. When you contact the seller - you get a similar message every time - "The item will be shipped from and I would like you to pay though Western Union". They remove them eventually if you complain, but the point is, the fact that more are appearing means that they're still finding it very easy to hijack your account.
Nick...
> Even "classic" mode is a bear, because the control panel is all munged up. Erg!
...and the start menu too if you want. No-ones stopping you. You can make it almost identical to 2K if you want - it's quite easy (which is the whole point of Windows).
Well put the control panel into classic mode too then! Duh!
Unless eBay can sort out the massive amount of fraud that's going on right now then I'm never using it again anyway.
There seems to be an absolutely massive problem at the moment with people hijacking eBay accounts and their associated e-mail addresses and eBay don't seem to want to anything about it.
Anyone who uses eBay and has a weak password on their e-mail account (or an obvious answer to their secret question) is vulnerable to having their eBay account taken over (complete with e-mail account and credit card details) and used by a Western Union scammer.
What's a Western Union scammer? Someone who asks to be paid though Western Union (who offer zero buyer protection or tracking of funds) and then simply never ships the item. Western Union seem happy to dish out funds to anyone so the fact that the account is in the wrong name doesn't seem to cause any problems.
eBay should make it so it's impossible to take over an account by changing the password/and/or e-mail address unless you know lots of personal information (D.O.B., mothers maiden name, etc etc).
I'm finding it very difficult to get eBay to reply or for any news agencies to give this any publicity.
Over the weekend I saw about 30 Sony plasma screens advertised (usually "pre-approved bidders only") - almost none of which were legitiate. When you contact the seller - you get a similar message every time - "The item will be shipped from and I would like you to pay though Western Union". They remove them eventually if you complain, but the point is, the fact that more are appearing means that they're still finding it very easy to hijack your account.
Nick...
1 release != 1 generation
ISA = 1st gen
Vesa Local Bus and PCI are essentially just different versions of the same thing = 2nd gen
So PCI express will be 3rd Gen.
AGP is a bit different as it's graphics only.
Scientists have also found a way to remove Dihydrogen Monoxide from water in a process called "deaquificiation".
Actually I've only got the Cisco PIX 501, so maybe that doesn't support bridging mode. I can't find anything in the docs about how to configure this.
You're right - I haven't actually tried, I was just repeating what I'd been told by our firewall supplier (who may or may not be particularly knowledgeable).
:)
The other criteria which I forgot to mention is that we also need VPN support. Can a bridging firewall support VPNs when, it doesn't actually have an external facing IP of it's own? Presumably it would have to create a virtual IP address and use that for the VPN?
I don't really want to try building one myself using BSD, as then it would be my fault if it didn't work
Nick...
While it's on topic, I've always wondered how many people use transparent firewalls. I work for a small web development company in the UK and as such we have about 30 IP which host a few public facing webservers as well as our mail and stuff. We decided to use a transparent firewall (ie, one that lets us keep our 30 real IP addresses on the machines which are public facing - rather than 192.x or 10.x addresses) so that if there were any problems with it, we could just remove it (physically) and everything would still work. No network reconfiguration required.
But it seems that it's quite uncommon for firewalls to even support this feature and even less common for people to actually use it in this mode. Is there a reason that more firewalls don't support this functionality, or are there good reasons not to configure your network like this?
A major problem we would have if we used something like a Cisco PIX is that we wouldn't be able to see the websites we are hosting. The domain would map to a normal internet facing address, yet we can't see those addresses from the LAN (they don't seem to apply the port mapping to connections that have come from the LAN - so we'd need to look at them on their internal IP or something).
How many people actually use transparent firewalls? Or how do you get round the problems above if you're a web hosting company and you don't have a transparent firewall? Do any decent firewalls (apart from Sonicwalls) actually support this?
Nick...
OK, I probably didn't explain myself very well: A simple NAT firewall, such as that built into Windows XP and quite a few routers, will allow all outbound traffic by default. From the outside however, all ports that don't have an outbound connection will appear to be closed (as opposed to open, or non existant/stealth). "Closed" meaning that the computer actively sent back a packet saying that it doesn't accept connections on that port. Meanwhile, you can happily run games/P2P/ICQ etc without noticing that you're even behind a firewall - without SPI.
SPI works on another level - rather than forwarding connections, it actually analyses the raw packets and decides whether or not to forward them. It can even be set to be completely unresponsive on the ports that are not in use meaning that if no ports are open, there is no way to tell that there is a computer at that IP address. It can also do some clever stuff, like inspect the contents of packets and conditionally allow the traffic or perhaps open another port based on it's contents.
All I was trying to point out was that you don't need SPI to get the ease of use you were talking about.
Certainly some routers may require you to manually open outbound ports before something will work, but this isn't because they are (or aren't) SPI firewalls - it's more to do with the default configuration. Netgears allow all outbound traffic by default, but they could easily have been shipped to only allow HTTP, POP3 and IMAP4 by default, and block everything else.
The BEST feature of SPI firewalls is that *some* of them can be transparent. Meaning that if your firewall is protecting 30 machines, those machines can keep their real internet IP addresses and you just insert the firewall in the middle - no network reconfiguration required. eg, the Sonicwall Pro 230 does this. As far as I know, no NAT type firewalls can do this, meaning your internal servers all need to be moved to a private IP (eg 192.168.*.*) in order to work behind the firewall. If it breaks and needs to be removed, you need to either quickly replace it, or remove it and reconfire the IPs on every single machine behind the firewall.
You're very confused. This behaviour is absolutely nothing to do with stateful packet inspection. *ALL* routers will behave like this if you enable routing of all outbound traffic - even really cheap and simple NAT firewalls (not really even a firewall). Allowing all outbound traffic means that any trojans you get though e-mail/floppy/open HTTP port etc etc mean that the trojans can phone home and start sending out personal information or attacking other systems. Hardly secure...
The particular Netgear firewall you mentionned (FM114P/FR114P) is one I've used at home. It's probably the least stable and most annoying piece of hardware I've ever used. If you read the forums on dslreports.com you'll see that most users are plagued with problems ranging from random lock ups (mine needs rebooting every couple of days) to it's inability to handle long URLs (causes lock ups) and it's susceptability to the common ping of death attack, which means anyone on the internet can lock up your router with a simple ping command. I've had most of these problems myself, and if you combine them with the poor performance (especially if WEP is enabled) and power supply problems, you end up with a pretty poor product where the only redeeming factor is it's price. I think Netgear have resolved a few of these issues with the latest firmware, but they should have got it to this stage BEFORE releasing it, not a year or two afterwards! Why it takes 12 minutes to copy a 100mb file across the network - when both machines are in line of sight with the router and have full signal strength is beyond me! That's only 135k/sec which is almost exactly 1Mbit - and it's supposed to be an 11Mbit network - not exactly fast!
Nick...
Well, some guy in California has bought laos.com and he will probably sell them subdomains for a thousand dollars. :)
> How can you collect sales tax on a used item?
You can't. And no-one's saying they will. They're talking about eBay themselves collecting the VAT - not the *sellers* on eBay! You never pay eBay for the items - you pay the seller. The seller then pays eBay a listings fee and this is what will be taxed - not the item.
The exception perhaps would be new goods, but that would be up to the selling vendor to ensure they charge people the appropriate tax for their region.
G is already a measurement of acceleration. Ie 1G = 9.80665m/s/s if my memory serves me correctly.
You can't damage something more by subjecting it to the same acceleration for less time! The only affect that would have, would be to leave the object at a lower speed - it has not been any more 'stressed' because the acceleration lasted less long.
If we're talking about something like metal fatigue, then the magnitude, combined with the frequency of oscillation of the accelleration, *might* then correlate to the *time* taken to break the metal concerned (but not necessarily the probability). But that's about as close as I can come to making sense of your post...
Measuring G per second is silly.. that means you're measuring in meters per second per second per second! A totally nonsensical measurement for anything!
It sounds like you made that up and you're not actually basing your hypothesis on any facts... I wish there was a "-1, Wrong" in the moderating list.
15G is nothing - that's like dropping the card onto carpet from about 2ft. Not exactly stressful for some solid state hardware - even a hard drive could probably cope with that while running. The duration doesn't make much difference - providing they don't exceed the amount of G required to break something (probably more like 80+G). The vibrations might cause the G level to peak much higher than the overall accelleration of the rocket however.
I would have thought that vibrations are much worse than the overall acceleration of the rocket; Anyone ever taken a computer out of the back of a car (which probably never exceeds 1.5G) only to find that some screws have come loose or a PCI card has fallen out? (cos I have!).
It's a television - not a monitor (hence the words "television" in the article and on the manual) but you can use it on a PC. 1024 is easily enough to view PAL TV (720x582 lines) or even the lower resolution American system (NTSC) which I think is effectively 640x480 maximum. No wonder TV looks fuzzy when you go to America - I hadn't realised there was such a difference until I checked the stats.
If you want a monitor, there are much higher resolution LCD displays available. It's only 21" but the Eizo L985EX is very well reviewed.
I didn't think there was any guarantee that with SA on, it would always average out to be zero over a certain unit of time? ie, can't they leave SA strayed in one direction for a very long amount of time and therefore mess up the results?
You realise that the UK doesn't use the Euro don't you?
First of all, all GPSs take a short while (10-300 seconds) to work out where they are when you first turn them on. How long it takes depends on a number of things:
So turning it on for the first time in the last few weeks is bound to take a while - but that's the same for all GPS positions... it just takes time to download the new orbital position information from a satellite it can 'see', before it knows which ones it should be able to see and try and lock on to.
BUT, to increase the accuracy of GPS, many countries have also implemented a DGPS system (Differential GPS or other similar systems designed for use by aircraft on final approaches). This greatly increases the accuracy of a GPS receiver by letting it receive information from fixed base stations about the error imposed by environmental conditions, satellite mis-alignment or SA (Selective Availablity) and allows the unit to correct for these and maintain it's full accuracy to a very high level (perhaps a few centimeters instead of several feet). This system though, is pretty much useless in the context of the article as the base stations are going to be moving as well.
What I expect happens in this context is a GPS is left in a fixed position for a very long time and is therefore able to average out it's readings over a long period of time so that the errors are virtually eliminated. Because the land moves so slowly - it doesn't matter if it takes a really long time to get an accurate reading - and reading averaged over the period of several months is going to be really accurate (perhaps to centimeter level, or close to the resolution of the GPS).
None of this will work however, if the US switches SA back on (Selective Availability) which is an artificially imposed error designed primarily to prevent other nations from having access to a very reliable signal that could be used to build highly accurate GPS guided bombs. However, SA has been turned off for quite a while now and has only been turned on again (I think) during the Iraq conflict for security reasons. Allied military units can easily correct for this error, but other nations won't have the hardware or codes required to decrypt it.
There are a couple of new GPS systems due to come online soon that are going to be even more accurate than the existing US system. Hopefully this will be available to civilians worldwide and will mean that extra DGPS hardware isn't required for things like navigation close to cliffs and rocks.
Nick...
...you tell me this *after* I've just bought a house in Southampton. Bummer. I knew the must be *one* good reason to live in Scotland...
Nick...