Slashdot Mirror

Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.

No, they're not the same concept, and the electromagnetic plane launcher that they are building here cannot readily be re-purposed as a railgun.

The EMALS (electromagnetic air launch system) is a Linear Induction Motor which works just like a standard AC motor except it has been laid out flat instead of in a circle. The launch carriage has a set of alternating magnetic poles (the stator) and it is driven by a series of series of coils which are driven with the appropriate AC waveform as the carriage passes overhead.

A Railgun contains no permanent magnets, it uses a current through the projectile (or through a projectile carrier) to create a Lorentz force with the current in the rails which propels the projectile.

In principle one could attempt to design a linear induction motor as a weapon, but since the point of a railgun is to achieve extremely high exit velocity (current Navy efforts have achieved on the order of 2.5km/s, shooting for 5km/s) it will be very challenging to achieve the appropriate rise/fall times in the driving coils. The need for permanent magnets in the projectile are also a problem, and I imagine there would be issues with magnetic fields saturating the projectile unless the magnitudes are limited, meaning the weapon must be longer.

I could see a role for LIM directly as a weapon only if there were some application where you need to launch a relatively very heavy projectile at relatively small exit velocity.

A lot fewer moving parts and better control over the stroke energy

Looks like they've done over 220 test fires of this already in 2010

http://www.navair.navy.mil/NewsReleases/index.cfm?fuseaction=home.view&id=4468

http://en.wikipedia.org/wiki/Electromagnetic_Aircraft_Launch_System#Advantages

You rarely have mail stolen...

This should be emphasized....

And the government sends secret documents by the U.S. Postal Service.

A simple Google search would bring up this.

Hell, I just hit https://www.navy.mil/ and my browser puked because they were trying to us a certificate that was only good for akamai's domain.

I think this particular instance was more a matter of poor security practices in web development than underlying OS or web server, but it does seem a bit odd that a military branch would use Microsoft/IIS vice using a Unix or Linux platform. It appears that the U.S. Navy is also running IIS for their primary public site.

200 OK
Cache-Control: max-age=334
Connection: close
Date: Mon, 08 Nov 2010 16:56:47 GMT
ETag: "8094fdaf44cc81:287"
Server: Microsoft-IIS/6.0
Content-Location: http://www.navy.mil/usnhome.html
Content-Type: text/html
Last-Modified: Thu, 11 Oct 2007 20:24:13 GMT
Client-Date: Mon, 08 Nov 2010 16:56:48 GMT
Client-Peer: 96.17.8.152:80
Client-Response-Num: 1
Header: US Navy
X-Powered-By: ASP.NET

Didn't that lead to a hospital being targeted and destroyed?

Nope, they went there to rescue some medical students. They picked up some heavier resistance than expected, but didn't blow up a hospital.

Problem is that footprint is very important - it is why many helicopters have folding-rotor variants. (Especially naval helos.)

Also, big footprint makes SAR missions like the one impossible - http://www.navy.mil/search/display.asp?story_id=55440 (There's a video on CNN somewhere but it's hard to find, CNN has one of those annoying "automatically moves on to next story" setups that makes sharing videos/finding them later hard.)

Carter was not a nuclear engineer. He was briefly preparing to become an engineering officer of a nuclear sub, but he was never a nuclear engineer.

A better (aka factual) reason for banning reprocessing is nuclear proliferation; reprocessing produces enriched plutonium which had little or no use other than making nuclear bombs. The US essentially promised not to produce enriched plutonium if everyone else would do the same. But in the process we sacrificed a lot of efficiency in the nuclear fuel cycle.

I think it's high time we reevaluated that position and consider allowing reprocessing now that we have well established technology to use plutonium as nuclear fuel.
=Smidge=

There are good technical reasons why FDR data doesn't make sense to upload raw data automatically.

The pure FDR data is sampled at a high data rate, which varies according to model of FDR. The most modern systems also collect hundreds of data points at a time. This is discussed in the article, though I'd challenge some of their bandwidth calculations... the sample rates they quote seem very low (for modern systems), though I don't have my books in front of me.

What DOES make sense (and again, the article does address this), is having computing capability in the FDR (or outside of it, as it wouldn't need to be crash-worthy) that filters the data and ID's in real-time out-of-normal events and reports them.
In fact, most airlines already use a system like this, but not for the purpose of crash monitoring, but to detect aircraft problems in flight and alert ground crew so they can they can be prepared to fix them before the pilots even know there was a problem.

The issue is that this uplink capability can't replace the on-board FDR recording capability. That black box must still be there, as during the crash sequence, there is a good chance your satcom/etc systems will fail before the final crash. So this can augment, but not replace.

They also discuss adding a capability to comb through the complete raw data (you can just download it on landing as another route). Yep, great idea, but already being done by many airlines.
See http://www.boeing.com/commercial/aviationservices/brochures/Airplane_Health_Management.pdf

And in fact, the military is using the FDR data to check their pilot's proficiency as well as the aircraft performance:
See http://www.navair.navy.mil/PMA209/_Documents/MFOQA_101_20090224.ppt

Would that be before or after the US blows up said country to hell and shoots everyone? Seriously dude, when the fuck has the US ever parked a "hospital ship" or did you get that mixed up with "hostile ship"?

No, he meant "hospital ship". And it has been used without US blowing up a country, but you probably think US caused the earthquake to occupy Haiti.

Well, seems that PlanetAll was launched November 16, 1996 according to this, while the original patent application dates back to November 2, 1997.

The clocks in orbit are either Rubidium or Cesium based. The US Primary Time Standard is a Cesium Fountain.

http://tf.nist.gov/cesium/fountain.htm

The GPS clocks are synchronized to the Master Clock.

http://tycho.usno.navy.mil/clocks.html

http://tycho.usno.navy.mil/mc_to.html

The clocks in orbit are either Rubidium or Cesium based. The US Primary Time Standard is a Cesium Fountain.

http://tf.nist.gov/cesium/fountain.htm

The GPS clocks are synchronized to the Master Clock.

http://tycho.usno.navy.mil/clocks.html

http://tycho.usno.navy.mil/mc_to.html

Interesting. Yeah, "abandoned" does mean up for grabs so far as I know.

The law on what is abandoned is complicated and I don't know it; I do know that maritime and international law are very weird and difficult. There's even an "Abandoned Shipwreck Act." But I'm not so sure the fisherman's rule is the law. I bet you wouldn't have boarded OR scavenged a sinking U.S. Navy ship .....

Who owns U.S. Navy ship and aircraft wrecks?

The Department of the Navy retains custody of all its ship and aircraft wrecks unless specific, formal action is taken to dispose of them. The administrative act of striking an aircraft or ship from the active list does not constitute disposal. Even aircraft and ship wrecks that are stricken from the active list remain the property of the United States until such time affirmative action is taken to dispose of these properties, such as sale, or other action in accordance with law.

http://www.history.navy.mil/faqs/faq28-1.htm#anchor74432

More to the point, civilian boats, I don't think that's the law but I don't know much. It definitely is not abandoned at the moment the crew flees (cowards!). Here is a Wikipedia entry you might like: http://en.wikipedia.org/wiki/Shipwreck#Salvage_of_wrecks ("As a general rule, non-historic civilian shipwrecks are considered fair game for salvage." -- but the Shipwreck Act says "The law specifies that any wreck that lies embedded a state's submerged lands is property of that state and subject to that state's jurisdiction if the wreck is determined as being abandoned.")

How was it, being a fisherman? Sounds like a tough life. THEY get their own set of laws, too (as seamen, for taxation, etc.).

it did say

Submarine Type
All self-propelled submersible types regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability.
  Attack Submarines
      Submarine SS
      Submarine SN (Nuclear-Powered)
CURRENT US NAVY SHIP CLASSIFICATIONS

so I suppose the SS refers to Self-propelled Submersible as apposed to non-self-propelled submersibles.

Maybe this will help you.

List of US Navy ship and service craft classifications

Correct. However the link in the summary is incorrect - dazzle camouflage was widely used in WWII. Some of the schemes used by the USN can be seen here.
 
It's worth pointing out however that proper studies of the effectiveness of dazzle camouflage seem to have never been carried out.

Now, there is a wholly different issue of value: a lot of the wrecks are potentially worth millions of dollars and at least some of the issues that have arisen where the armed forces attempt to reclaim a warbird by claiming it's their property are because it's the last of a kind and an armed forces museum wants it, and the one I read about specifically, was a case where the Air Force wrote a contract specifying that it was a loan to one organization, and that organization then tried to sell it to another organization, which is when the AF stepped in and attempted to reclaim it.

Very considerably indeed...

(TFA gives no real sense of how much power is involved in their setup, so it is hard to say how much accelerating it could be made to do; but magnetic accelerators in general are capable of impressive velocities. Though, much to the dismay of science-fiction fans everywhere, they require vast amounts of electricity, so handheld versions of any practical use are awaiting the invention of some treknobabble power source.)

I had a mild headache from Avatar Imax 3d with polarized glasses. With the Digital 3d with LCD glasses version, I did not have a headache, but my left eye/visual cortex wigged out and started dropping information. My laser correction surgery changed my eye dominance(from left eye to right eye due to my right being 20/20 and my left being 35/20) and the Dig3d seemed to screw something up in my brain more then my eye. It was truly weird and persisted for 2 days. I went to CES and no system seem to be ok. I tried a few LCD 3d versions, and got sick to my stomach. I stopped looking at LCD, and tried a few direct view, but when you were at the correct distance, it was a small picture. I like to sit CLOSE to a tv, and 3d w/out glasses limits you to a SPECIFIC distance. Also without glasses you see the grating/lenses in front of the image and it is much poorer quality. I guess that it doesn't help that IN avatar they have perfect flat and curved 3d and the large holographic table that shows what 3d should look like. It should be doable with a head tracking "display" with a laser putting 2 separate images on the back of each retina kinda like a stereoscopic version of this. http://www.cs.nps.navy.mil/people/faculty/capps/4473/projects/fiambolis/vrd/vrd_full.html

You'd be astonished how badly sextants work in fog or in a rainstorm.

In September 1923 in pre-Loran days, the US Navy ran seven destroyers onto the rocks at Honda Point in California. http://www.history.navy.mil/photos/events/ev-1920s/ev-1923/hondapt.htm Those ships had plenty of sextants and navigators that knew how to use them. ... and they did not know where they were.

I have a classmate who is a major in the US Navy...

He is a major... in the US Navy... hmm.

http://www.navy.mil/navydata/navy_legacy_hr.asp?id=266

Here's how. All government procurement has special programs for buying from small business, and in fact are required to spend a certain percentage at small businesses. Congress mandates it, 'cause it makes good press with the voters.

Oh, for the lazy curious, here's a couple links:

http://www.navy.mil/navydata/cno/n87/usw/issue_34/one.html
http://navysite.de/ssn/ssn575.htm

and while looking at the wikipedia article (http://en.wikipedia.org/wiki/United_States_Naval_reactor), I noticed that the Soviets did try some liquid metal cooled (not sodium, but bismuth-lead) submarine reactors. Crazy Ivan indeed.

Hot sodium and water don't get along well, and there's plenty of water to be had around a submarine, in the event of a coolant leak, things go from bad to worse. Call me Captain Obvious.

[Sigh] Though that page repeats the (completely false) urban legend that Blueback was used in The Hunt for Red October...
 
There's also the Submarine Museums page from the USN, which links not only to submarines on display, but to other museums with submarine exhibits.

How has this been modded informative? Do you understand nothing about code breaking? (and cryptogeeks, I am talking about codes, not ciphers). You match up codewords with their meaning through observation or trickery. A classic example was the use of an in the clear message about a desalination plant to identify Midway as target AF during WW2. http://www.history.navy.mil/faqs/faq81-3.htm

How about the other type of tether - the long one. (gravity-gradient) There were supposed to be 3 shuttle experiments with tethers, and at last report I think they'd done the first and smallest, and had trouble with the second. (snarling/breakage?)

http://adsabs.harvard.edu/abs/1989fmet.symp..149L
http://www.satobs.org/tss.html
http://code8100.nrl.navy.mil/programs/tips.htm

The actual shuttle experiments seem to be concerned with "dropping" a probe into the very upper atmosphere for measurments and observation. The third reference, non-shuttle deployed, seems to be materials/duration research.

None seem interested in generating effective gravity or skyhooks/pinwheels.

I can't read the article due to Slashdot effect, but if shuttle launches are contributing to or causing (big difference there!) the formation of the noctilucent clouds then there should be a correlation to check for.

They did and there was - http://www.nrl.navy.mil/pressRelease.php?Y=2003&R=35-03r

warriors/ship-driver-wannabes here:

http://blog.marport.com/2009/06/

http://www.fas.org/man/dod-101/navy/docs/swos/eng/64b7-205.html
(read the Bleed Air section and the Prairie Air section beneath it...)

good views are in:

http://www.globalsecurity.org/military/systems/ship/systems/prairie.htm

http://www.fas.org/man/dod-101/navy/docs/swos/eng/index.html

To add to the good comments that prop is the noise introducer from other components in the shaftline, readers (who read, that is) might be interested to see this:

http://www.gibbscox.com/nsv.htm

Shock mounting in the hull helps absorb certain frequencies of noise that otherwise would be emitted.

This one has nice pretty colors for those who are visually-oriented.

http://metocph.nmci.navy.mil/KBay/backgroundnoise.htm

Now, for those wanting to know what a ship looks like under the stresses of the sea, and you think it's a huge honkin' piece of unbending steel, look at page 13 in:

http://www.mscsoftware.com/support/library/conf/wuc94/p01994.pdf

But, for all of you having wet dreams about the 16% fuel savings, keep in mind it is "UP TO", it's by NO means guaranteed. Considering volatility in fuel prices and potentially unstable regimes providing oil, some circles see smaller lightweight nuc plants as a viable alternative.

(From above: http://blog.marport.com/2009/06/ )

Thinking about it a bit more, in comparison, the ideal temperature for DT fusion is 15 keV = 174,000,000 K. I don't know what the pp fusion cross section vs temperature looks like, but since it's not in the tables of the NRL Plasma Formulary it's probably not worth pursuing.

The old US Naval Observatory was located in Foggy Bottom, just across from where the Kennedy Center is now. If you are coming in from Virginia across the Roosevelt Bridge, you can see at one point the old dome for the 26 inch telescope, where Hall discovered the moons of Mars.

This site is now the Bureau of Medicine and Surgery for the Navy. I bet that the article is referring to a bunker at Observatory Circle.

From the Navy textbook:

(c) Applications Software. Ensure that procedures are in place for routine backup of programs and documentation after any change or update. In addition to the working copy, it is recommended that three backup copies of all software be made to support a Contingency Plan. One backup copy is maintained at the working site. A second on-site copy is stored in a fireproof container in an area away from the normal processing area. A third backup copy is stored at an off-site location. It is recommended that a rotational backup system be used to ensure that no magnetically recorded file remains in a stored status for more than six months. Comparisons of files should be made prior to rotation. Verify any discrepancies to assist in preventing the introduction of viruses into backup copies.

(d) Data files. Data files required to support recovery operations (master files or data bases) must be maintained similarly to applications software. Implement procedures to ensure data files are backed up after each update. Maintained files in a manner which facilitates easy restoration of the system at the backup site.

http://www.cs.nps.navy.mil/curricula/tracks/security/AISGuide/navch09.txt

Way back when, I would access the Naval Research Lab's websites for copies of OPIE (a one-time password suite), their IPSec code, their IPv6 code and their IPv4/IPv6 multiprotocol suite.

These days, they have some nice stuff in the areas of multicasting, wireless routing and network testing tools.

Even the DoD's Office of Information Security Research has done Open Source work before, publishing one of the early IPSec implementations publicly through MIT.

So other than the DoD finally putting onto a more official level a practice that has been commonplace for decades (the sharing of source under true open source licenses), what exactly is new here? That the politicians at the top of the food chain figured something out? That's just a freak event, a result of the statistical nature of quantum mechanics.

What did I do first with Linux? Install it.

I gave yggdrasil a go, I guess that it was early to mid 90s. To be honest, I wasn't all that impressed with yggdrasil so I abandoned it fairly quickly. You've got to remember that I was used to Micro-Port Unix (a port of Sys V for the PC), which was more stable. It didn't have the X Windowing System on it but that wasn't a real problem for me back then.

My next stop along the Linux trail was Redhat, circa version 5. That was a keeper. What did I do with it? Learn its web and database server capabilities. Learn how it differed from the various flavors of Unix that, as a software developer, I was already familiar with. I remember being pretty happy with the -R command line switch which Unix didn't have.

I was in the navy and trained extensively in ASW operations. They don't use active sonar that is sonar that emits sound much

The US Navy doesn't use active sonar? "Spr08_Training With Active Sonar While Protecting Marine Life [pdf]".

Falcon

I was in the navy and trained extensively in ASW operations. They don't use active sonar that is sonar that emits sound much

The US Navy doesn't use active sonar? "Spr08_Training With Active Sonar While Protecting Marine Life [pdf]".

Falcon

I believe this is extremely slow, and usually only done if you're becalmed or have no sails/masts left. I recently read 'Six Frigates', about the original U.S. Navy frigates, and apparently it was occasionally used to get a bit of extra speed, as when Constitution escaped a British squadron.

Interesting, when checking to make sure I had my facts straight for this post, I found this:
The Captain's writings about the incident. Very interesting if you like this sort of thing.

My own guess is that the writers for Star Trek took 'warp' more from physics or other science fiction, rather than nautical usage, but who knows?

Sadly, its primarily Aircraft Carriers that are aflicted with this cursed disease. If I ever come to power, the Navy will not get a dime until it renames the Reagan, Bush, Vinson, and Ford as Yorktown, Lexington, Saratoga and Hornet, the next one after that had better damned well be named Enterprise!

Why would you want to rename USS FORD? http://www.ford.navy.mil/default.aspx You're unhappy about the convention of naming carriers for people who fund the Navy, and then you rename a frigate.

What I've read about the Jan. 2005 X-class flare event, the energetic proton burst arrived at only 15 minutes after visual detection of the flare, telling me that (A) 15 minutes is a historically realistic value for "least amount of warning from Earth-based optical sensors", and (B) protons from a very energetic flare can get accelerated to .33C, which is scary*. I'd hate to be in a spacecraft or on ISS when that happens. It'd be like standing in a particle accelerator beam tuned up to 100MeV.

*Actually, accelerated faster than .33C. This paper seems to be saying that there was about a 2-3 minute delay from start of flare to particle injection. I think. As I've said elsewhere, I'm not a space physicist or a geosolar meteorologist, just a long-time kibitzer.

The system relies on sending sound waves that locate objects by bouncing off of them.

Thank you! Simply saying it relied on SONAR would have left us all completely befuddled.

Well yes and no. Typical military SONAR operates in the 2 kHz to 10 kHz range or sea floor mapping SONAR at 5 kHz, while OAWRS is significantly lower from 300 Hz to 1.5 kHz. It is also different than typical SONAR in that there is a transmitting vessel and a separate receiving vessel. Using separate transmit and receive locations that are a significant distance from each other also differentiates it from conventional long range SONAR which operates at 500 Hz. Here's a link that describes OAWRS in more detail if you're interested: http://www.onr.navy.mil/sci_tech/32/reports/docs/08/oamakris.pdf

Yeah:
Here's #1 and
#2 and
#3.

Yeah:
Here's #1 and
#2 and
#3.

Yeah:
Here's #1 and
#2 and
#3.

Just so nobody starts thinking this is real again:

http://www.navy.mil/navydata/navy_legacy.asp?id=174

It's still funny though!

http://www.navy.mil/navydata/navy_legacy_hr.asp?id=174

There are better pictures courtesy of the US military
http://www.nrlmry.navy.mil/~cannon/medports/Faslane/HMNB_picture.html

http://www.nrl.navy.mil/

this lab also tends to prefer a particular type of orange.

From TFA:

So, what if we really wanted to find Atlantis? We probably couldn't do it with satellites — man-made structures simply aren't big enough to be measured that way. But we could map the whole ocean using ships. A published U.S. Navy study found that it would take about 200 ship-years, meaning we'd need one ship for 200 years, or 10 ships for 20 years, or 100 ships for two years. It costs about $25,000 per day to operate a ship with the right mapping capability, so 200 ship-years would cost nearly two billion dollars. That may seem like a lot of money, but it's not that far off from the price tag of, say, a new sports stadium.

The water belt-line of the Iowa class Battleships are 12.2 inches of SOLID steel. They were designed to take more kinetic energy than any anti ship missile can dish out. The Yamato http://www.history.navy.mil/photos/sh-fornv/japan/japsh-xz/yamato.htm had double that armor thickness and was firing projectiles over 18 inches in diameter that had HUGE amounts of kinetic energy in them that would make the largest non nuclear anti-ship missile look like a firecracker.

Honestly we have went backwards in firepower because the ships at sea right now are very easy to sink compared to what we had during WW-II in the world.

yes airstrikes work very well, plus the Yamato was taken out simply because we overwhelmed the Japanese navy. We basically did a berlin firebombing on the Japanese naval fleet in that battle.

Note: The battle off Samar where the Yamato was sunk is known as one of the absolute largest naval battles in history. we also almost lost that one even though we had 16 carriers and 400 aircraft fighting.

the Yamato did not go down easily. WE had to pound it pretty darn hard.