Possibly where he means is the islands of Novaya Zemyla (sp) which at least according to a lot of newspaper clipping research I did many years ago in high school is where the USSR dumped quite a few reactors and other assorted nuclear waste and according to a quick google search they did nuke tests. Not that Ive heard they intend to do this this time.
Personally I'd rather believe an aeronautical/aerospace engineer than a physicist (but then im biased;) ), no offence to physicists but i hardly think that many would have expertise in that area unless it was their special area of research. Similarly i wouldnt think a doctor would have much of a clue about what happens to an aircraft structurally in a depressurisation situation. A doctor would however if they specialised in the area be able to tell you what effects the depressurisation would have on the human body.
For some accident reports on explosive decompressions and their effects on the aircraft you should take a look at some of the following sites or browse around the NTSB (US), AAIB(UK) and BASI (Australia) sites. Some links of direct interest as they cover explosive decompressions include:
As for the medical side there is an excellent article on avweb on the effects of hypoxia. As you can see from this article consciousness can be lost in anywhere from minutes to seconds depending on altitude and how quickly the decompression occurs.
The mach number in flight is not the only factor involved in determining the shock angle. The deflection angle of the body which is being subjected to supersonic flow also plays a role in determining the shock angle. For example if the incident freestream is mach 2 and a wedge with a half angle of 10 degrees was considered then the shock wave angle would be 39.2 degrees. However if we still have mach 2 flow acting on a wedge with a half angle of 20 degrees we end up with a shock angle of 53 degrees. Mach number also affects it as if we take the same wedge with the half angle of 20 degrees and subject it to a mach 5 flow the shock angle becomes 2.9 degrees. (As i cant be bothered grabbing values myself off the graphs these are shamelessly lifted out of examples in John Anderson's book "Fundamentals of Aerodynamics" which is quite a good textbook imho).
My experience is different, in the Australian public school system 5 years ago it was essentially forced (from the point of view of the student), the only way out of not being subjected to some person trying to convince one of the merits of believing in their god was if your parents felt strongly enough about the matter to write to the principal to excuse you. Now whilst my parents felt that it would be a good experience for me to learn a bit about the predominant religion in Australia and hence possibly understand the people who believe in god more, i felt that being subjected to this sort of rubbish was a waste of my time. I didnt feel this because i didnt want to learn about how another group feels regarding religion but more because as a group these people were completely unable to understand why one would want to question them and the bible and lacked any skills to defend their point of view at all. Take for example one guy who came in and thought it would be a good idea to tell a collective group of around 130 final year students that the world is only 5000 years old and yet he could not provide any substantial evidence for his claims other than the bible says so. Hardly the sort of thing which i feel education is about.
I think the only consolation i had in being subjected to this was it was only a couple of times a year.
Just one thing i sorta have a little problem about, i agree that to remotely pilot a combat aircraft you need a lot of data however the data you mention isnt the stuff i would imagine would be the main mass of the data. The amount of instrument data (assuming you send it as data and not video... not really sure why you said a video feed from the cockpit as one wouldnt really expect a cockpit in a ucav) would be pretty small in comparison to the sensor data you would require to engage targets (again i 'spose this makes the assumption that the ucav carries its own sensor suite and doesnt rely on awacs/jstars to do its targetting).
Just going on your comments regarding recognition means being broken by enemy forces reminded me of something i heard a few years ago about some of the supposed capabilities on newer model F-15 Eagle's and their radars. Apparently it had the capability to identify (dont know how reliably) aircraft by the characteristics of the radar return it received from the compressor and fan in the enemy aircraft. Anyone with knowledge of radar systems care to comment on whether this sort of thing is possible? Naturally this sort of approach to identification is rendered much less effective by the use of S-shaped inlet ducts, use of radar absorbent materials and shaping of the external surfaces. However as most current generation aircraft dont have these features and altering the characteristics of an inlet and generally reducing the radar cross section of an existing design would be prohibitively expensive (generally speaking (the F/A-18E/F is one example of an existing system being redesigned for some stealth )). It seems an interesting way to do the ID if it is possible and also a difficult one to spoof(as changing the compressor design wouldnt be an option without a redesign of the propulsion system) if you have accurate data on the returns produced by other aircraft with which to compare your received signal.
Im sure i found this link on/. a few weeks ago but for the life of me i cant find the story it was in. Anyhow the link is here and basically is a paper discussing the secure deletion of data, it goes into a little detail on erasure of information using magnetic fields and according to the paper it is currently not possible to completely erase most magnetic media using current degaussing equipment. Naturally if someone was wanting to read your data after it had been through this process as outlined in the paper they would have to go to considerable trouble but still i guess it depends on what stands to be gained from getting access to the data.
The paper also has an interesting bit on recovering data from RAM after power has been removed.
Anyways food for thought:)
Hiya,
Theres already a host of such brilliant sites around, probably the best i've ever come across was run by Fravia who unfortunately has decided to close it down, if you are very lucky you may be able to find one of the mirrors still alive. In its place he has created a great site which deals largely with search engines and searching the web as well as many other interesting topics. He still has a few links to reverse engineering stuff however. You can find his site here.
Some other sites which are up there with Fravia's site include: Mammon's Site
Crackz r.e site here and here
The Sandman's code reversing for newbies. Greythorne the Technomancer's
These are just a few of the many out there however imho they are the best i have come across.
Cheers, VI
Well if you believe some of the misguided christians who impose their beliefs on young children/teenagers in the public education system of Australia you would find that your last statement was sometimes sadly true. To me one of the most valuable things to my education when i was young was being encouraged by my parents and other individuals to always ask questions about the world around me, however i found that in scripture/religous instruction classes this kind of inquisitive thinking was discouraged and i cant help but think that in some small way this attempt to suppress the natural tendencies of young people to question their environment is partly responsible for the way reverse engineering is often seen as a bad thing.
Cheers,
VI
Ummm you may wanna try micq , dunno if command line interface cranks ya handle but at least it has no ads and runs on many platforms, it covers my needs as far as icq goes.... so long as you dont mind typing instead of clicking and can live without all the fancy crap.:)
On a similar note if you are interested in filtering out some of these 1x1 gifs and ads from sites you can find sample windows hosts.sam files with a list of less than desirable web ad sites etc at Fravia's Searchlores page. Just do a local search on his site for doubleclick and you get quite a few links to lists of addresses you could add to your hosts.sam file(in windoze) or i assume (as I havent tried it yet)/etc/hosts.
A direct link to one of the lists can be found
here
It would put us in a state where most coders and inventors would be legally liable for something...
What is necessarily wrong with an inventor or a coder being responsible for their code or design any more than an engineer being legally liable for his/her designs? There isnt much of a difference between the type of work that an engineer does compared to a coder or an inventor , and as an engineer i believe that i should have some form of accountability for any design i make as those designs could cause a loss of life or loss of income if i make an error through being negligent. I can understand that someone who writes software which they make freely available shouldnt be held liable for damages due to some problem with it so long as it is made clear the software could be buggy and shouldnt be trusted. However for the case where software is purchased i believe that the designers should be held accountable and if that requires a legal liability to ensure that the coders are thoroughly testing their software to comply with their claims for the software's performance then i cant see a problem with that.
I dont really want to comment one way or another on his chances of success without knowing more about the guy but just wanted to point out your error when saying he wont have to worry about heat shielding. I think that is something which would be important to his design as at Mach 4 which iirc was the figure mentioned in the article the aerodynamic heating effects are going to be quite noticeable. Take for example the SR-71 Blackbird which travelled at ~mach 3 the figure i remember being about the maximum skin temp was 1400deg F. So obviously you would want to isolate the occupant from those sort of temperatures through shielding and also you would want your material to maintain strength at those temperatures. If you take the blackbird as an example the choice of material (titanium) was pretty exotic at the time (design began in the late 1950s) due to the requirement for a light weight but high strength material able to maintain strength at elevated temperatures... conditions which are not all that different to what this guy has to design for. Other interesting abstracts of tech reports on aerodynamic heating effects on the X-15 can be found on NASA Dryden's web server (the papers themselves should be able to be found in any half decent engineering library with an aeronautical/aerospace department). The X-15 was an experimental rocket powered aircraft flown by NASA iirc in the late '50s/early '60s at mach numbers between 3 and 6 and altitudes approaching those mentioned in the article. Cheers, Village Idiot
Just a couple of points, if by portable launchers you mean small shoulder fired type missiles such as the stinger,sa-7 etc then the problem would be they rely on infra-red detection and with a plane optimised to be stealthy in the infra-red spectrum and which also may be flying above 20000 feet or so(where shoulder launched missiles are often said to become ineffective , i'm not sure whether this is due to the control surfaces becoming ineffective or whether it is their rocket motor doesnt burn long enough to engage above this altitude.... anyone know?). If you are talking mobile as in mobile launch vehicles then i would imagine there is a fair chance that one would be able to pick up the vehicle by its infrared signature, or possibly by airborne radar such as that on the JSTARS aircraft. Second point on the matter of B-52's being used over B-1's and B-2's i believe that at the time of the gulf war most of the B-1's werent capable of dropping conventional munitions and it is only since then that they have been converted. Also if you are hinting that the B-1B isnt a very good replacement then if you believe Ben Rich's book "Skunk Works" the only reason it got built was because Reagan promised the Californian electorate(Rockwell was situated there i believe) he would reinstate the B-1 program which Carter had cancelled due to the development of stealth technologies. Whether improvements to the aircraft have made it useful or not would probably be a better question for a bone driver. On the B-2 i guess the argument could be that if you are going to be able to fly an aircraft that is nearly 50 years old into a certain low threat situation and do the same job as one which is brand new but worth over $1bn which would you choose?
Ive only ever seen one account of this and that was at Farnborough about 2 years ago. The USAF claimed that the reason the British(i think its a british company which makes the Rapier, correct me if im wrong) company involved was able to was because they knew the exact flightpath the aircraft would follow and hence were able to set the radar up so the chance of detection was favourable. If you know anything about other instances it would be interesting to hear.
Im not sure but i sort of read it differently. (im an aero eng student,not elec so i dont really know how commercial radio signals would reflect/distort due to the actual aircraft, rumour has it that some radars with a longer wavelength can detect the F-117 but not actually track it( the missile guidance radar is a much shorter wavelength and ive heard the f-117's facetting is optimised for these wavelengths)) I read the story that it was the air turbulence caused by the aircraft that distorted the radio signals not the actual aircraft however im the first to admit my interpretation could be wrong. My main reason for reading it that way was that there has recently(read 10 yrs or so) been a lot of research into detecting clear air turbulence and windshear and thought this could have been a spinoff from someone's research. If it is then i guess it would be interesting as clear air turbulence cannot be detected by radar and so far the only methods which have to my knowledge been successful are using Lidar(uses a laser beam which will reflect off aerosols and dust hence providing data on the air mass ahead).
Your second idea was very similar to my thoughts on the matter. On simulating falling etc you could probably just move the harness up and down rapidly and providing you made the harness support rigid you could also tilt the occupant in the harness to give them the feeling of moving on sloping terrain ala flight simulators movements which fool the body into perceiving certain motions. The simulation of say climbing a ladder etc could be given by using pressurized pockets in the suit to put pressure on the occupant's hands and feet etc to simulate the rungs of the ladder etc. Cheers
Heck if ya that keen to run UT and it'll take you half a day to download maybe someone could post you a copy of the linux binaries gzipped on a floppy or two. Hopefully someone in the US will be able to help you out but if not email me and ill send it... whats a couple of dollars postage?
Just to make a point about your statement about Quake 3 and Quake 2, why did you decide to choose Quake 2 over Quake 1 when all you had to do was get omicron bots/frogbots etc?:) What is the difference between Q2 and Q1... as i see it not as much as the difference between Q3 and Q2. Although to be perfectly honest the biggest difference i see between versions is in eye-candy value:) and to me that is trivial when compared to the feel of the game. That is why i still run in 320x200 w/out a 3d card and play winquake/netquake instead of quakeworld. But i can understand others points of view that the graphics make the game even if i dont agree. Just my 2 cents:)
Slashdot Mirror
Possibly where he means is the islands of Novaya Zemyla (sp) which at least according to a lot of newspaper clipping research I did many years ago in high school is where the USSR dumped quite a few reactors and other assorted nuclear waste and according to a quick google search they did nuke tests. Not that Ive heard they intend to do this this time.
Personally I'd rather believe an aeronautical/aerospace engineer than a physicist (but then im biased ;) ), no offence to physicists but i hardly think that many would have expertise in that area unless it was their special area of research. Similarly i wouldnt think a doctor would have much of a clue about what happens to an aircraft structurally in a depressurisation situation. A doctor would however if they specialised in the area be able to tell you what effects the depressurisation would have on the human body.
For some accident reports on explosive decompressions and their effects on the aircraft you should take a look at some of the following sites or browse around the NTSB (US), AAIB(UK) and BASI (Australia) sites. Some links of direct interest as they cover explosive decompressions include:
Air accident investigation board (UK)
NTSB - Inspired improvements in transportation safety - PDF file(do a search for decompression to find relevant bits)
As for the medical side there is an excellent article on avweb on the effects of hypoxia. As you can see from this article consciousness can be lost in anywhere from minutes to seconds depending on altitude and how quickly the decompression occurs.
The mach number in flight is not the only factor involved in determining the shock angle. The deflection angle of the body which is being subjected to supersonic flow also plays a role in determining the shock angle. For example if the incident freestream is mach 2 and a wedge with a half angle of 10 degrees was considered then the shock wave angle would be 39.2 degrees. However if we still have mach 2 flow acting on a wedge with a half angle of 20 degrees we end up with a shock angle of 53 degrees. Mach number also affects it as if we take the same wedge with the half angle of 20 degrees and subject it to a mach 5 flow the shock angle becomes 2.9 degrees. (As i cant be bothered grabbing values myself off the graphs these are shamelessly lifted out of examples in John Anderson's book "Fundamentals of Aerodynamics" which is quite a good textbook imho).
My experience is different, in the Australian public school system 5 years ago it was essentially forced (from the point of view of the student), the only way out of not being subjected to some person trying to convince one of the merits of believing in their god was if your parents felt strongly enough about the matter to write to the principal to excuse you. Now whilst my parents felt that it would be a good experience for me to learn a bit about the predominant religion in Australia and hence possibly understand the people who believe in god more, i felt that being subjected to this sort of rubbish was a waste of my time. I didnt feel this because i didnt want to learn about how another group feels regarding religion but more because as a group these people were completely unable to understand why one would want to question them and the bible and lacked any skills to defend their point of view at all. Take for example one guy who came in and thought it would be a good idea to tell a collective group of around 130 final year students that the world is only 5000 years old and yet he could not provide any substantial evidence for his claims other than the bible says so. Hardly the sort of thing which i feel education is about.
I think the only consolation i had in being subjected to this was it was only a couple of times a year.
Just one thing i sorta have a little problem about, i agree that to remotely pilot a combat aircraft you need a lot of data however the data you mention isnt the stuff i would imagine would be the main mass of the data. The amount of instrument data (assuming you send it as data and not video ... not really sure why you said a video feed from the cockpit as one wouldnt really expect a cockpit in a ucav) would be pretty small in comparison to the sensor data you would require to engage targets (again i 'spose this makes the assumption that the ucav carries its own sensor suite and doesnt rely on awacs/jstars to do its targetting).
Just going on your comments regarding recognition means being broken by enemy forces reminded me of something i heard a few years ago about some of the supposed capabilities on newer model F-15 Eagle's and their radars.
Apparently it had the capability to identify (dont know how reliably) aircraft by the characteristics of the radar return it received from the compressor and fan in the enemy aircraft. Anyone with knowledge of radar systems care to comment on whether this sort of thing is possible?
Naturally this sort of approach to identification is rendered much less effective by the use of S-shaped inlet ducts, use of radar absorbent materials and shaping of the external surfaces. However as most current generation aircraft dont have these features and altering the characteristics of an inlet and generally reducing the radar cross section of an existing design would be prohibitively expensive (generally speaking (the F/A-18E/F is one example of an existing system being redesigned for some stealth )). It seems an interesting way to do the ID if it is possible and also a difficult one to spoof(as changing the compressor design wouldnt be an option without a redesign of the propulsion system) if you have accurate data on the returns produced by other aircraft with which to compare your received signal.
Im sure i found this link on /. a few weeks ago but for the life of me i cant find the story it was in. Anyhow the link is here and basically is a paper discussing the secure deletion of data, it goes into a little detail on erasure of information using magnetic fields and according to the paper it is currently not possible to completely erase most magnetic media using current degaussing equipment. Naturally if someone was wanting to read your data after it had been through this process as outlined in the paper they would have to go to considerable trouble but still i guess it depends on what stands to be gained from getting access to the data.
:)
The paper also has an interesting bit on recovering data from RAM after power has been removed.
Anyways food for thought
Hiya, .
Theres already a host of such brilliant sites around, probably the best i've ever come across was run by Fravia who unfortunately has decided to close it down, if you are very lucky you may be able to find one of the mirrors still alive. In its place he has created a great site which deals largely with search engines and searching the web as well as many other interesting topics. He still has a few links to reverse engineering stuff however. You can find his site here
Some other sites which are up there with Fravia's site include:
Mammon's Site
Crackz r.e site here and here
The Sandman's code reversing for newbies.
Greythorne the Technomancer's
These are just a few of the many out there however imho they are the best i have come across.
Cheers, VI
Well if you believe some of the misguided christians who impose their beliefs on young children/teenagers in the public education system of Australia you would find that your last statement was sometimes sadly true. To me one of the most valuable things to my education when i was young was being encouraged by my parents and other individuals to always ask questions about the world around me, however i found that in scripture/religous instruction classes this kind of inquisitive thinking was discouraged and i cant help but think that in some small way this attempt to suppress the natural tendencies of young people to question their environment is partly responsible for the way reverse engineering is often seen as a bad thing.
Cheers, VI
Ummm you may wanna try micq , dunno if command line interface cranks ya handle but at least it has no ads and runs on many platforms, it covers my needs as far as icq goes .... so long as you dont mind typing instead of clicking and can live without all the fancy crap. :)
On a similar note if you are interested in filtering out some of these 1x1 gifs and ads from sites you can find sample windows hosts.sam files with a list of less than desirable web ad sites etc at Fravia's Searchlores page. Just do a local search on his site for doubleclick and you get quite a few links to lists of addresses you could add to your hosts.sam file(in windoze) or i assume (as I havent tried it yet) /etc/hosts.
A direct link to one of the lists can be found
here
It would put us in a state where most coders and inventors would be legally liable for something...
What is necessarily wrong with an inventor or a coder being responsible for their code or design any more than an engineer being legally liable for his/her designs? There isnt much of a difference between the type of work that an engineer does compared to a coder or an inventor , and as an engineer i believe that i should have some form of accountability for any design i make as those designs could cause a loss of life or loss of income if i make an error through being negligent. I can understand that someone who writes software which they make freely available shouldnt be held liable for damages due to some problem with it so long as it is made clear the software could be buggy and shouldnt be trusted. However for the case where software is purchased i believe that the designers should be held accountable and if that requires a legal liability to ensure that the coders are thoroughly testing their software to comply with their claims for the software's performance then i cant see a problem with that.
I dont really want to comment one way or another on his chances of success without knowing more about the guy but just wanted to point out your error when saying he wont have to worry about heat shielding. I think that is something which would be important to his design as at Mach 4 which iirc was the figure mentioned in the article the aerodynamic heating effects are going to be quite noticeable. Take for example the SR-71 Blackbird which travelled at ~mach 3 the figure i remember being about the maximum skin temp was 1400deg F. So obviously you would want to isolate the occupant from those sort of temperatures through shielding and also you would want your material to maintain strength at those temperatures. If you take the blackbird as an example the choice of material (titanium) was pretty exotic at the time (design began in the late 1950s) due to the requirement for a light weight but high strength material able to maintain strength at elevated temperatures... conditions which are not all that different to what this guy has to design for. Other interesting abstracts of tech reports on aerodynamic heating effects on the X-15 can be found on NASA Dryden's web server (the papers themselves should be able to be found in any half decent engineering library with an aeronautical/aerospace department). The X-15 was an experimental rocket powered aircraft flown by NASA iirc in the late '50s/early '60s at mach numbers between 3 and 6 and altitudes approaching those mentioned in the article. Cheers,
Village Idiot
Either that or he finds the shooting down of a Korean Airlines 747 funny.
Just a couple of points, if by portable launchers you mean small shoulder fired type missiles such as the stinger,sa-7 etc then the problem would be they rely on infra-red detection and with a plane optimised to be stealthy in the infra-red spectrum and which also may be flying above 20000 feet or so(where shoulder launched missiles are often said to become ineffective , i'm not sure whether this is due to the control surfaces becoming ineffective or whether it is their rocket motor doesnt burn long enough to engage above this altitude.... anyone know?). If you are talking mobile as in mobile launch vehicles then i would imagine there is a fair chance that one would be able to pick up the vehicle by its infrared signature, or possibly by airborne radar such as that on the JSTARS aircraft.
Second point on the matter of B-52's being used over B-1's and B-2's i believe that at the time of the gulf war most of the B-1's werent capable of dropping conventional munitions and it is only since then that they have been converted. Also if you are hinting that the B-1B isnt a very good replacement then if you believe Ben Rich's book "Skunk Works" the only reason it got built was because Reagan promised the Californian electorate(Rockwell was situated there i believe) he would reinstate the B-1 program which Carter had cancelled due to the development of stealth technologies. Whether improvements to the aircraft have made it useful or not would probably be a better question for a bone driver. On the B-2 i guess the argument could be that if you are going to be able to fly an aircraft that is nearly 50 years old into a certain low threat situation and do the same job as one which is brand new but worth over $1bn which would you choose?
Ive only ever seen one account of this and that was at Farnborough about 2 years ago. The USAF claimed that the reason the British(i think its a british company which makes the Rapier, correct me if im wrong) company involved was able to was because they knew the exact flightpath the aircraft would follow and hence were able to set the radar up so the chance of detection was favourable.
If you know anything about other instances it would be interesting to hear.
I read the story that it was the air turbulence caused by the aircraft that distorted the radio signals not the actual aircraft however im the first to admit my interpretation could be wrong. My main reason for reading it that way was that there has recently(read 10 yrs or so) been a lot of research into detecting clear air turbulence and windshear and thought this could have been a spinoff from someone's research. If it is then i guess it would be interesting as clear air turbulence cannot be detected by radar and so far the only methods which have to my knowledge been successful are using Lidar(uses a laser beam which will reflect off aerosols and dust hence providing data on the air mass ahead).
Cheers
Your second idea was very similar to my thoughts on the matter. On simulating falling etc you could probably just move the harness up and down rapidly and providing you made the harness support rigid you could also tilt the occupant in the harness to give them the feeling of moving on sloping terrain ala flight simulators movements which fool the body into perceiving certain motions. The simulation of say climbing a ladder etc could be given by using pressurized pockets in the suit to put pressure on the occupant's hands and feet etc to simulate the rungs of the ladder etc.
Cheers
Would it be too much to hope that that person was actually a disgruntled worker at Redmond trying to undermine the Linux community? ;)
Cheers,
V.I
(e4gle_ttc@yahoo.com)
Just to make a point about your statement about Quake 3 and Quake 2, why did you decide to choose Quake 2 over Quake 1 when all you had to do was get omicron bots/frogbots etc? :) What is the difference between Q2 and Q1 ... as i see it not as much as the difference between Q3 and Q2. Although to be perfectly honest the biggest difference i see between versions is in eye-candy value :) and to me that is trivial when compared to the feel of the game. That is why i still run in 320x200 w/out a 3d card and play winquake/netquake instead of quakeworld. But i can understand others points of view that the graphics make the game even if i dont agree. Just my 2 cents :)