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Comment: Rail gun vs. "Conventional" (Score 2) 517

by slackoon (#48999141) Attached to: The US Navy Wants More Railguns and Lasers, Less Gunpowder
The bullet in this case is just a massive piece of metal. It is accelerated to a ridiculous speed (a Navy weapon capable of hurling 40-pound projectiles at speeds of 4,500 mph to 5,600 mph over 50 to 100 miles (7,240 to 9,010 kilometers per hour over 80 to 161 kilometers). This is the advantage of railguns, very high bullet speeds. This gives the bullet a massive amount of energy.

The weapon works by basically smashing into something else, transferring most of that kinetic energy into whatever it hits which ultimately ends up as heat. This is the same reason brake pads on cars get hot, transfer of kinetic energy into heat.

When the projectile hits something and stops, the bullet and whatever it hits will get very hot. The projectile is probably made of metal which is in fact very flammable if you get enough oxygen to it. So there is a fireball, either because whatever it hits is flammable or because the projectile/whatever it hits is burning.

When you hit something that fast the behavior of metals changes. The speed of sound (see * below) in metal is high but if you hit something fast enough, then you can actually exceed the speed of sound in a metal and the rear of the projectile will carry on moving as though it hasn't hit anything when the front has hit something. This is the same idea of a shock-wave in air but it's in metal. Heres a good youtube video:
http://www.youtube.com/watch?v...

Well needless to say this tends to result in some funky stuff, like the metal bullet tearing it's self apart into lots of small pieces. This is a big driver in some anti-tank weaponry. If you hit the armour just right then you can actually get the inside of the tank to shatter, basically turning the inside of the tank into a shrapnel grenade, killing the operators.

If the projectile shatters then it's going to be hot and have a large surface area and you can get lots of oxygen to it which will result in a fireball, potentially it will burn about as hot as 1000 K. This to me seems like a good thing to design for because the added heat is going to do things like start fires and ignite conventional bullets/warheads and burn through armour.

* The speed of sound refers to the maximum speed at which a mechanical vibration (much like the pressure changes that cause sound. Not like light, RF, or electricity) can travel through a medium. Mach1 refers to that maximum speed of those wave's permeation through air, however different media such as water, metal, and glass will have different values for that maximum speed.
So, as the projectile hits some theoretical immovable object, the front will stop, but the rest will continue collapsing in on the front, faster than the pulse created on initial impact (a mechanical vibration that would otherwise influence the rear of the projectile to slow down) can travel to the rear of the projectile.
A bad, but visual representation of this is if you had a long line off cars driving down the freeway bumper to bumper. The first crashed and was brought to a halt instantaneously. In a normal crash each car behind would generally apply brakes and slow down before impact. However, for this example, everyone is driving faster than their own reaction time, so they are part of the pileup before they have registered an accident happened in the first place.
http://www.reddit.com/r/askscience/comments/22iqo3/why_does_the_us_navy_rail_gun_round_explode_into/

Comment: won't automatically connect to WiFi (Score 1) 120

by slackoon (#48941735) Attached to: Wi-Fi Issues Continue For OS X Users Despite Updates
I have to say that my internet on my MacBook pro still drops once in a while. However it's drastically improved. The biggest thing is that I would have to select the network and re logon every time I woke up the computer. it never did it automatically. Now it does!!

As discussed on this forum

1st World Problems ;)

Comment: introduced species...OH NO!!! (Score 1) 265

The Cane Toad was also a "good idea" with a "proven background" and...well...we all know how that went

"The cane toad is native to South and Central America, but when its introduction to regions of Hawaii, the Caribbean, and the Philippines to fight pests in sugarcane fields yielded impressive results, it was quickly imported to various other regions worldwide.

Unfortunately, cane toads have a nasty habit of not just eating crop pests and insects, but also just about any terrestrial animal that they can fit their grotesquely huge mouths around — which is saying something, given that they can grow to over 30 cm in length. They also secrete toxins capable of killing just about any animal they come in contact with (humans have died after ingesting their eggs), meaning that they tend to be seriously lacking in the natural predator department."
Source here

Comment: what the vaccine actually do? (Score 2) 178

by slackoon (#48885757) Attached to: New Nicotine Vaccine May Succeed Where Others Have Failed
from the article "Though a vaccine wouldn’t be a silver bullet—there would still be withdrawal symptoms—a person may be less motivated to relapse because the brain’s reward system could no longer react to nicotine"

so for all those being critical of this vaccine please keep in mind it's not supposed to "make you quit". It's more like it takes away your reason for doing it. Smokers will no longer get the good feelings from a cigarette so they will be more inclined to quit. If used as a vaccine they will be less likely to start again or start in the first place.

+ - Anonymous claim first victory against jihadists

Submitted by slackoon
slackoon writes: 'Hacktivist' group Anonymous has fired the opening salvo in its online war on terror groups following the Charlie Hebdo massacre.

The loose-knit collection of hackers said it would shut down jihadist websites in retaliation for the terror attacks on the Paris-based office of the French satirical newspaper and a subsequent attack on a Jewish deli on Friday.

Now it has emerged that the group, which holds freedom of speech sacred, claimed on Twitter that it had struck ansar-alhaqq.net, a French terror-mongering website.

The Twitter account, @OpCharlieHebdo, also posted '#TangoDown', a reference to a military term meaning a terrorist has been eliminated. Source

+ - Thermocouple technology

Submitted by slackoon
slackoon writes: The lantern’s operation is based on a phenomenon known as the Seebeck effect, using thermocouple technology to generate an electrical current by exploiting the temperature difference between the inside of the lantern and the cooler outside air. As long as the candle inside the lamp housing is burning, the LEDs will continue to emit light.

Source

This thing actually works, question is, how can we use this tech in a proper /. kinda way?

Comment: Re:Study debunks nothing at all, move along (Score 1) 19

by slackoon (#48765643) Attached to: Study Casts Doubt On Mammoth-Killing Cosmic Impact
I could not agree more. It's the widespread layering of strata that leads researchers to believe there was an impact. As you said "Those scoria were indeed local and made in fires - like the vast fires that spread everywhere after the airburst" So unless there were BILLIONS of fires lit over an ENORMOUS area then it wasn't "Stone age house fires".

In addition I'd like to point out that there are countless studies that support the conclusion that a cosmic impact triggered the Younger Dryas cold period and only a handful that support otherwise.

Comment: What result are they looking for? (Score 1) 448

by slackoon (#48610647) Attached to: Virtual Reality Experiment Wants To Put White People In Black Bodies
So there should be a fundemental research question that this research will answer, what exactly is that question?
"What’s most exciting about this channel of research is that it gets at the kind of complex, subtle prejudices that most people can’t even articulate if asked directly."
in other words...

They are going to try to find racism where none actually exists and then call white people racist.

Comment: Newfanese (Score 3, Funny) 99

by slackoon (#48609179) Attached to: Skype Unveils Preview of Live English-To-Spanish Translator
If you're from Canada you'll understand when I say

Let's see it handle Newfaneese!!!!
examples here
“Who knit ya?”
Translation: Who’s your mother/parents?
This one doesn’t need too much explanation, but try telling your mother that all she was doing for nine months was “knitting.”
“I’m gutfounded. Fire up a scoff.”
translation "I'm hungry, make some food" Translation: I’m hungry. Make me some food.

Comment: A++ & MCP (Score 3, Funny) 276

by slackoon (#48401293) Attached to: World's Youngest Microsoft Certificated Professional Is Five Years Old
I used to work tier 2 tech support for RoadRunner. People, usually from Florida, would call in complain their internet wasn't working. I would always get people trying to let me know just how smart they were.

Customer: "Hi, I'm A++ and MCP certified and I have a certificate from Devry so I know my stuff but I can't get my internet working"

Me: "What makes you say it isn't working Sir, what exactly is going on?"

Customer: "I can't load any websites except ones I've seen before, I tried restarting but it's just doing the same thing"

Me: "...type ipconfig, what do you see?"

Customer: "...static IP..."

Me: "Sir, do you have a kid who uses your computer for gaming? You have a static IP, that's the issue. follow these instructions and it will work..."

Customer: "No, I certainly don't have a static IP. I looked for that. The issue must be on your end"

Me: *FACEPALM!!!!!!!

comclusion: MCP MEANS NOTHING!!!!!!

Comment: recruit based on potential (Score 2) 253

Recruiting based on potential is kinda like the hoy grail I suppose but there are ways. Almost any coder can get a decent mark in JAVA 101. That doesn't mean much in an interview. What you want is to know if the person has the ability to learn quickly, think critically etc. so HOW THE @#&$@ do you test that??

One example came from the language training I took. The training was for English speakers to learn French so they spent 30 minutes teaching us a few words, counting and the alphabet in Kurdish. WTF right?...wrong!! it was brilliant. None of us had a clue about Kurdish so when they tested us they found out what we learned in that 30 minutes. That let them know our potential to learn, motivation etc.

SO WHAT? In a job interview you already know they have a certain base of knowledge from their resume. Now give a quick 5-10 minute talk on some obscure programming language, database concept...whatever. Then ask the interviewee questions on it, ask them to expand concepts that were taught. How they react and the quality of their answers will give you great insight into their potential.

Comment: NRA is everywhere (Score 2) 43

by slackoon (#48301371) Attached to: Japan's Annual Nuclear Drill Highlights Problems
"Some 3,700 people took part, including about 1,000 residents near the plant and participants from a variety of government agencies, including the Cabinet Office, the NRA, the Defense Ministry and the National Police Agency."

It's always a problem when the NRA and Charlton Heston are mixing up the long gun debate and nuclear watchdog drills

my 3 year old can unlock the ipad, swipe to the next screen, load an app and have fun, why can't the PhD I work with?

Hacking's just another word for nothing left to kludge.

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