Ok, let's assume the hydrazine tank is made of titanium and that the titanium tank would not melt during reentry. Accepting TripMasterMonkey's assertion that hydrazine boils at...what was it? 118 degrees C?...and that reentry temperatures reach 1400 C, you still have a problem. What happens to a liquid when it boils? Pressure increases, right? So you have a tank that is designed to hold a liquid propellant in space, but now it is heated to 1400C. The hydrazine inside, heated to *over ten times its boiling point*, causes a rapid and drastic increase in the pressure inside the tank. Can you guess what happens next?
Steel aerosol cans have the warning "do not dispose of in fire" printed on them for a reason.
Looks to me like the terrorists have landed a grand slam on/., then. I'm just guessin', so I could be wrong, but did your parents *really* name you "Daimanta"? It might be a last name, but it sounds more like a pseudonym to me. FWIW, no, element-o.p. is not my real name either (although you can probably find it with a bare minimum of effort if you follow the links to my website):P
it's refusal to hear this case swings the door wide open to allow the Executive branch to operate without any regard to Constitution in the areas where Constitutional review is most needed.
I couldn't agree with you more. This is a most depressing ruling from the Supreme Court. Sigh...
Yeah, that's pretty much it. When I first figured that out in high school civics, I thought it completely unfair, but think about it...it's the Supreme Court. If you think a law is unconstitutional, you have to break the law, get arrested, then have your day(s) in court. Basically, nothing gets changed unless you are willing to take a stand.
While it kinda sucks for the activist, I guess it's one way to keep from having to hear cases from every stupid schmuck who wants to challenge a law that doesn't personally affect him/her from wasting the court's time with trivial lawsuits.
emerge exiftool did the trick -- it returns lot's more info than my script above. BTW, forgot to escape a couple of special characters in the one-liner I posted. It should have been "cat ...
I've got a perl script on my linux box that uses Image::Magick to convert the images to other sizes (for example, for creating thumbnails for web pages), and I was surprised to see the Exif data even in my thumbnails as well as the original. Good to know just in case you don't want an image being possibly tracked back to your camera...
Very cool...I wrote a one-liner script** on my linux box to look at some JPEGs I recently took with my Canon Powershot. It looks like it is definitely recording make and model of the camera, and a time/date stamp, but I don't see any thing in the Exif data that is *obviously* a serial number. However, that could just be a limitation of my script, since I'm throwing away all of the binary data. Now I'm gonna have to go look for an Exif reader program to see for sure
**Here's my one-liner for anyone who's interested in parsing your own Exif data:
cat | sed "s/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\:\;\'\"\,\<\.\>\/\?]//g" | grep Exif
Hmmmm...interesting idea, but I'm not sure it would work, since the (arguably) most common format for such pictures is JPEG, which is a lossy format. Obvious watermarks (like those you see on many web pages) will work, of course, but isn't there a risk that a watermark that was sufficiently slight to prevent a human from noticing also be sufficiently slight to be erased by the JPEG compression algorithm? I don't know that it wouldn't work; just askin':)
My dad and younger brother played with BeOS for a while, but I never did give it a try. About the time I was ready to install it on one of my machines, they pulled the plug on the project:(
IIRC, one of the big selling points of BeOS was that it was designed to be used for multimedia applications. I remember seeing pro/serious-amateur hardware recording gear on Musician's Friend that was compatible with BeOS. If Haiku picks up where BeOS left off -- and people like M-Audio or MOTU make gear that is compatible with Haiku -- I'll *definitely* put Haiku on one of my machines...hmmmm...maybe my new Athlon x2:D
GILA: American765 please turn right heading...Windows error 0x345d339e0942faa
System error...please contact your system administrator.
Abort, retry, ignore?
American765: WTF???
I call B.S. on that. Have you ever heard of a vapor lock? You take regular 80-proof alcohol (I forget what kind, offhand, but 80 proof is ~40%), pour it into a tall glass, light it with a match, then cup your hand over the opening to smother the flame. Then you quickly remove your hand and take a deep breath. The flame vaporizes the alcohol, and when you inhale the vapors, you get the alcohol into your bloodstream very, very quickly. /.'ers forgetting to make sure the flame is out before trying a vapor lock>
I've never seen anyone make a Molotov cocktail, so I won't claim to know that 80-proof alcohol is strong enough for that, but I *have* seen someone light a vapor lock, so I know that 80-proof alcohol will burn easily enough to be lit with a single match -- no preheating required.
I'll be...I guess 1000 feet isn't out of the question after all. From this guy's description, it's really, really hard and takes a long time (he said seven hours), but it's possible. If you factor in that Al Qaeda has proven many times over that they are willing to blow themselves up for Allah, then I'd guess they could go even deeper if they chose.
Whether or not Paul or Huckabee have a snowball's chance is irrelevant *if* the fact that they are running forces other candidates to change their race. If we follow your logic, then we probably shouldn't be discussing Republicans at all this year, considering how many Republicans were recently removed from Congress, and that our (Republican!) president has such a staggeringly low approval rating.
I'll keep backing Huckabee -- regardless of what the polls say -- until *he* either wins or loses the nomination or decides to pull out of the race on his own.
Very insightful, and I think you are probably right.
For what it's worth, despite the fact that I tend to be politically conservative, *I too* am sick of what's happened to this country in the last several years, and I believe that HRC will be more of the same, only with a leftist bent. Obama makes me nervous because I just don't know enough about him, but I believe that HRC would be yet another disaster for our country. If I had to pick a Dem this year, it would definitely be Obama.
I think that the problem both in UK and in US is that people don't truest their government. I don't know if this is because of history of wrong doing in part of the government, or because of television and movies...
Unfortunately, I think that in the U.S. at least, most people *do* trust the government. I don't, and a lot of people here on/. don't, but I think that is more because history has shown again and again that governments that are not kept in check by their constituents tend to become abusive. In fact, the relative freedom that western societies have enjoyed for the last several generations are an historical aberration; one that I *don't* want to see corrected.
You're right, of course. There are ways to ensure that all your users are using secure passwords. The problem is, for the layman, secure passwords aren't something you can remember, so your average customer doesn't *want* a secure password, and gripes to Tech Support every chance they get. Then Tech Support complains to their manager that the customers are complaining about these impossible-to-remember passwords, the Tech Support manager complains to the Sys Admin manager (who tries to explain the need for secure passwords to the TSG manager), and eventually some PHB says to relax the restrictions on passwords.
In our case, it was just easier to turn off SMTP-auth altogether.
The problem with an ISP using SMTP-auth for connections outside their network is that SMTP-auth is only as secure as the least secure password used in your customer base. Given that people are generally lazy and prioritize convenience over security, that means odds are that any decent sized ISP *will* have at least one (and probably very many more) weak passwords, and *that* means that the ISP's mail server *will* be an open relay as soon as the spammers figure it out.
This isn't just theory -- at an ISP I used to work at, we saw this happen. We started getting UCE complaints from other ISP's, but couldn't figure out how spammers were relaying through our server. We traced it down to one customer's e-mail account, but couldn't figure out how hosts from outside our netblock were relaying through our server. Finally, one of the admins noticed that SMTP-auth was turned on (it wasn't supposed to be). I've lost all faith in SMTP-auth on an ISP server since.
Short answer -- a jet uses outside air as the oxidizer. A rocket carries an oxidizer with it. These devices carry H2O2 in a tank to use as an oxidizer. Therefore, this is a rocket pack, not a jet pack.
I suspect they are using rockets rather than jets because a jet requires a series of turbines to compress the air for combustion, but the (liquid) fuel and oxidizer are pumped into the rocket engine, making the rocket engines simpler and lighter.
Even wings just big enough to hold a 200lb person are pretty big. Assuming a coefficient of lift of 1.6 (fairly reasonable for a typical wing design), a density of 0.007...ummm...slugs, IIRC, and a landing speed of 25mph (still pretty fast for your feet, but we'll go with it for now), your wing area is...:
lift = 1/2*0.007*velocity^2*coefficient of lift*area
and therefore, wing area is 200 / 7.53 which is 26.6 square feet.
Assuming an aspect ratio (wing span / wing chord) of 6 (typical for light aircraft), that means your wing is 12.6 feet from wingtip to wingtip and just over 2 feet from the leading edge to the trailing edge. Okay, that's big, but not impossible. Unfortunately, that's just for the glider. If you now strap a 180lb rocket pack on, your wing gets even bigger -- now your wing is 17.4 feet from wingtip to wingtip and just under 3 feet from l.e. to t.e. That's getting pretty awkward:(
Slashdot Mirror
Ok, let's assume the hydrazine tank is made of titanium and that the titanium tank would not melt during reentry. Accepting TripMasterMonkey's assertion that hydrazine boils at...what was it? 118 degrees C?...and that reentry temperatures reach 1400 C, you still have a problem. What happens to a liquid when it boils? Pressure increases, right? So you have a tank that is designed to hold a liquid propellant in space, but now it is heated to 1400C. The hydrazine inside, heated to *over ten times its boiling point*, causes a rapid and drastic increase in the pressure inside the tank. Can you guess what happens next?
Steel aerosol cans have the warning "do not dispose of in fire" printed on them for a reason.
Looks to me like the terrorists have landed a grand slam on /., then. I'm just guessin', so I could be wrong, but did your parents *really* name you "Daimanta"? It might be a last name, but it sounds more like a pseudonym to me. FWIW, no, element-o.p. is not my real name either (although you can probably find it with a bare minimum of effort if you follow the links to my website) :P
I couldn't agree with you more. This is a most depressing ruling from the Supreme Court. Sigh...
Yeah, that's pretty much it. When I first figured that out in high school civics, I thought it completely unfair, but think about it...it's the Supreme Court. If you think a law is unconstitutional, you have to break the law, get arrested, then have your day(s) in court. Basically, nothing gets changed unless you are willing to take a stand.
While it kinda sucks for the activist, I guess it's one way to keep from having to hear cases from every stupid schmuck who wants to challenge a law that doesn't personally affect him/her from wasting the court's time with trivial lawsuits.
Can't be bad music -- the RIAA would never allow someone to listen to their music without paying the royalty :P
emerge exiftool did the trick -- it returns lot's more info than my script above. BTW, forgot to escape a couple of special characters in the one-liner I posted. It should have been "cat ...
I've got a perl script on my linux box that uses Image::Magick to convert the images to other sizes (for example, for creating thumbnails for web pages), and I was surprised to see the Exif data even in my thumbnails as well as the original. Good to know just in case you don't want an image being possibly tracked back to your camera...
Very cool...I wrote a one-liner script** on my linux box to look at some JPEGs I recently took with my Canon Powershot. It looks like it is definitely recording make and model of the camera, and a time/date stamp, but I don't see any thing in the Exif data that is *obviously* a serial number. However, that could just be a limitation of my script, since I'm throwing away all of the binary data. Now I'm gonna have to go look for an Exif reader program to see for sure
**Here's my one-liner for anyone who's interested in parsing your own Exif data:
cat | sed "s/[^a-zA-Z0-9\!\@\#\$\%\^\&\*\(\)\:\;\'\"\,\<\.\>\/\?]//g" | grep Exif
Hmmmm...interesting idea, but I'm not sure it would work, since the (arguably) most common format for such pictures is JPEG, which is a lossy format. Obvious watermarks (like those you see on many web pages) will work, of course, but isn't there a risk that a watermark that was sufficiently slight to prevent a human from noticing also be sufficiently slight to be erased by the JPEG compression algorithm? I don't know that it wouldn't work; just askin' :)
My dad and younger brother played with BeOS for a while, but I never did give it a try. About the time I was ready to install it on one of my machines, they pulled the plug on the project :(
:D
IIRC, one of the big selling points of BeOS was that it was designed to be used for multimedia applications. I remember seeing pro/serious-amateur hardware recording gear on Musician's Friend that was compatible with BeOS. If Haiku picks up where BeOS left off -- and people like M-Audio or MOTU make gear that is compatible with Haiku -- I'll *definitely* put Haiku on one of my machines...hmmmm...maybe my new Athlon x2
Aw, nuts...forgot a
and didn't preview the post.
"American765: WTF???" was supposed to be on a new line...
GILA: American765 please turn right heading...Windows error 0x345d339e0942faa
System error...please contact your system administrator.
Abort, retry, ignore? American765: WTF???
I call B.S. on that. Have you ever heard of a vapor lock? You take regular 80-proof alcohol (I forget what kind, offhand, but 80 proof is ~40%), pour it into a tall glass, light it with a match, then cup your hand over the opening to smother the flame. Then you quickly remove your hand and take a deep breath. The flame vaporizes the alcohol, and when you inhale the vapors, you get the alcohol into your bloodstream very, very quickly./.'ers forgetting to make sure the flame is out before trying a vapor lock>
I've never seen anyone make a Molotov cocktail, so I won't claim to know that 80-proof alcohol is strong enough for that, but I *have* seen someone light a vapor lock, so I know that 80-proof alcohol will burn easily enough to be lit with a single match -- no preheating required.
I was all set to argue with you about how deep you can go with SCUBA gear, but decided to check my facts first and found...http://www.inspired-training.com/depth_record.htm.
I'll be...I guess 1000 feet isn't out of the question after all. From this guy's description, it's really, really hard and takes a long time (he said seven hours), but it's possible. If you factor in that Al Qaeda has proven many times over that they are willing to blow themselves up for Allah, then I'd guess they could go even deeper if they chose.
Silly me -- I fat-fingered that one, didn't I?
NAK.
Whether or not Paul or Huckabee have a snowball's chance is irrelevant *if* the fact that they are running forces other candidates to change their race. If we follow your logic, then we probably shouldn't be discussing Republicans at all this year, considering how many Republicans were recently removed from Congress, and that our (Republican!) president has such a staggeringly low approval rating.
I'll keep backing Huckabee -- regardless of what the polls say -- until *he* either wins or loses the nomination or decides to pull out of the race on his own.
Very insightful, and I think you are probably right.
For what it's worth, despite the fact that I tend to be politically conservative, *I too* am sick of what's happened to this country in the last several years, and I believe that HRC will be more of the same, only with a leftist bent. Obama makes me nervous because I just don't know enough about him, but I believe that HRC would be yet another disaster for our country. If I had to pick a Dem this year, it would definitely be Obama.
I stand corrected; you are, of course, correct. Even though I try not to, I still sometimes fall victim to a U.S.-centric point of view :)
Unfortunately, I think that in the U.S. at least, most people *do* trust the government. I don't, and a lot of people here on
Sweet!!! Although the landing skids in the back make me think you'd better keep your face elevated when landing
You're right, of course. There are ways to ensure that all your users are using secure passwords. The problem is, for the layman, secure passwords aren't something you can remember, so your average customer doesn't *want* a secure password, and gripes to Tech Support every chance they get. Then Tech Support complains to their manager that the customers are complaining about these impossible-to-remember passwords, the Tech Support manager complains to the Sys Admin manager (who tries to explain the need for secure passwords to the TSG manager), and eventually some PHB says to relax the restrictions on passwords.
In our case, it was just easier to turn off SMTP-auth altogether.
But by the time you detect the spew, how many sites have already blacklisted your server?
The problem with an ISP using SMTP-auth for connections outside their network is that SMTP-auth is only as secure as the least secure password used in your customer base. Given that people are generally lazy and prioritize convenience over security, that means odds are that any decent sized ISP *will* have at least one (and probably very many more) weak passwords, and *that* means that the ISP's mail server *will* be an open relay as soon as the spammers figure it out.
This isn't just theory -- at an ISP I used to work at, we saw this happen. We started getting UCE complaints from other ISP's, but couldn't figure out how spammers were relaying through our server. We traced it down to one customer's e-mail account, but couldn't figure out how hosts from outside our netblock were relaying through our server. Finally, one of the admins noticed that SMTP-auth was turned on (it wasn't supposed to be). I've lost all faith in SMTP-auth on an ISP server since.
Short answer -- a jet uses outside air as the oxidizer. A rocket carries an oxidizer with it. These devices carry H2O2 in a tank to use as an oxidizer. Therefore, this is a rocket pack, not a jet pack.
I suspect they are using rockets rather than jets because a jet requires a series of turbines to compress the air for combustion, but the (liquid) fuel and oxidizer are pumped into the rocket engine, making the rocket engines simpler and lighter.
Even wings just big enough to hold a 200lb person are pretty big. Assuming a coefficient of lift of 1.6 (fairly reasonable for a typical wing design), a density of 0.007...ummm...slugs, IIRC, and a landing speed of 25mph (still pretty fast for your feet, but we'll go with it for now), your wing area is...:
:(
lift = 1/2*0.007*velocity^2*coefficient of lift*area
therefore, 200 lbs = 1/2 * 0.007*(25mi/h * 5280ft/mi * 1h/3600s)^2 * 1.6 * area
and therefore, wing area is 200 / 7.53 which is 26.6 square feet.
Assuming an aspect ratio (wing span / wing chord) of 6 (typical for light aircraft), that means your wing is 12.6 feet from wingtip to wingtip and just over 2 feet from the leading edge to the trailing edge. Okay, that's big, but not impossible. Unfortunately, that's just for the glider. If you now strap a 180lb rocket pack on, your wing gets even bigger -- now your wing is 17.4 feet from wingtip to wingtip and just under 3 feet from l.e. to t.e. That's getting pretty awkward
Just don't buy the Micro(cket-)soft version of the jetpack and you'll be fine :D (laugh, it's a joke!)