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No. 7005 ID: 9bee81 hide watch expand quickreply [Reply]
  So, is this stuff bullsit or not? Also is there a way to produce supercavitation effect in the air, so the bullet flies farther and retains more energy?
9 posts and 3 images omitted. Click Reply to view.
>> No. 7017 ID: 369bd6
File 142283273596.png - (810.73KB , 2000x1688 , 2000px-Phase_diagram_of_water_svg.png )
7017
>>7008
>>7015
I don't know if you noticed but thought I should clarify, I am pretty sure OP meant that question about supercavitating through the air as a secondary thought not related to his video or initial question. The video is about projectiles intended to supercavitate thought WATER to go further without bleeding off energy as quickly. (which is why I mentioned RAMICS which operates on the same idea) Once again, entering water before it supercavitates.



Phase diagram of water.
>> No. 7018 ID: a6b004
>>7015
I should have clarified, the ONLY part of the SR-71 that has any kind of shockwave cavitation is the engine inlet.

The hypersonic scramjet tests haven't been promising. Laminated composites don't hold up to the forces very well.

>>7013
me too.
>> No. 7019 ID: 052639
>>7017
Oh my bad, yeah undersea bullet cavitation is a thing
http://en.wikipedia.org/wiki/SPP-1_underwater_pistol
http://en.wikipedia.org/wiki/APS_underwater_rifle
>> No. 7020 ID: de0bec
  >>7017
>> No. 7023 ID: fb83e7
>>7015
Supersonic air is quite compressable.


File 142181423996.jpg - (118.40KB , 1024x881 , CAST-NASDAQ-halt-red-phone1.jpg )
6973 No. 6973 ID: cbf3af hide watch expand quickreply [Reply]
'Sup Opchan.

I promised this thread when we lost the battle against HR4681. Since that time the authorities, all the way down to your local cops, now have unfettered access to the NSA's illegal datamuhbase of your telephone and online communications. Peachy, huh?

While you may think you have nothing to hide, the point isn't that systems like these are used against ne'erdowells. Rather, when given a list of every phonecall someone has ever made, or every website they've ever visited, it becomes exceedingly easy to paint an innocent person to be guilty of something. Such power is historically used to hammer down any nails that stick up, and just because you aren't important enough to fuck over right now, doesn't mean they won't do something in the future you'll have a mind to speak up about.

So what is the solution? How about AGGRESSIVE PRIVACY.[i][/i]

The NSA's datamining efforts focus on three vectors: Telephone communication, websites you visit, and online communications like emails and IMs. Let's break their toys one by one.

Telephone comms are the hardest, due to issues of both technical ability (you know how to operate a SIM cloner? Me either.) and convenience. If you're encrypting your phone traffic, the poor bastard on the other end of the line has to be able to decrypt it, or your conversation ain't gonna be going anywhere. Looking at the simplest approaches to the problem lead me to one particular app:

Redphone. https://ssd.eff.org/en/module/how-use-redphone-android

Its free, runs on any android phone, works over WiFi or your data link so it doesn't eat your normal minutes, and does a pretty good job.
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>> No. 6994 ID: e02c14
File 142220740466.png - (13.60KB , 500x500 , logo.png )
6994
>>6993
Here's a little bit about other full disk encryption options that I looked at. I'm no computer security expert, but this is sort of a high level overview from what I remember.

Truecrypt 7.1a - Last real version. (AFAIK) Open source, different encryption options (AES Twofish Serpent), option to encrypt containers, partitions, or whole disks. Encrypts free space too. Takes ~16 hours to do 1 TB on a HDD. Works fine with SSDs, HDDs, external HDDs, and USB sticks. Works on Windows and Linux operating systems. (So if you dual boot, you can still get into your shit.) Uses it's own bootloader for full disk encryption, so I don't know how that works with your GRUB windows/linux/mac loader.

* Does not work on GPT partitioned drives, as mentioned above. Windows 8, I believe, is GPT partitioned by default. Also there's the detail that it was developed by some anon, who seems to have been partyvan'ed.

Truecrypt 7.2 - Bullshit decrypt only version. (Do not use!)

Cyphershed - The spiritual successor to TC with a stupid name. Last I checked, they're 2 weeks away from a release, 5 months ago. Developed by some Swiss fuckers, or something like that.

http://www.truecrypt.ch
https://ciphershed.org/

Symantec PGP Encryption - Closed source, costs money, my work laptop is going to this. Seems ok. Except that it's closed source, so there's no way to know if it's backdoored, and Symantec is shit. (Their anti-virus program drags my work laptop down to Pentium 1 windows 98 emulating a playstation 1 kind of load times.)
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>> No. 6995 ID: d4df2e
File 142224384048.jpg - (52.45KB , 500x502 , 1421424355524.jpg )
6995
>>6977
>Seriously who will realistically go without a phone?
I would if my job would let me.

I so fucking would.

>TOR is compromised
[citation needed]

>>6979
>>6984
These. Very well put.

>>6980
AFAIK, your only hope is statutes of limitations. Sorry, brah.
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>> No. 6996 ID: 8e6484
>>6995
>TOR is compromised

>[citation needed]


>The Tor Project Still Doesn't Know How Authorities Compromised Its Anonymity

>Nearly a week after government officials seized hundreds of Tor hidden services, the Tor Project is still unsure as to how the takedown was accomplished.

>Tor is an open source privacy network that encrypts messages through multiple network nodes. It’s supposed to keep users’ identities and locations discreet, but that has been called into question after Operation Onymous, a successful Europol effort that apparently infiltrated Tor and led to the arrests of 17 people operating vice-related sites on the network.

>In a Sunday blog post, Tor volunteers noted they were “as surprised as most” to hear about the seizures and were continuing to assess the damage after Europol seized hundreds of URLs hosted on about 27 websites, including the black market site Silk Road 2.0:

http://readwrite.com/2014/11/11/tor-privacy-post-takedown-vulnerability
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>> No. 6997 ID: 052639
>>6996
I think that was explained as an exploit in a completely different system, namely hushmail
>> No. 7000 ID: d7c33f
>Ever believing Tor is safe


File 142160878666.jpg - (2.78MB , 1780x3144 , Warded rim lock with bit key.jpg )
6960 No. 6960 ID: 0a2b37 hide watch expand quickreply [Reply]
Before pin-tumbler locks became commonplace most structures were secured using warded locks. Many old houses still use warded locks, there are two basic types:
Mortise locks which fit inside the door and door frame are mostly encountered on exterior doors as they offer greater security against forced entry by being part of the door structure.
Rim locks Mount onto the door and door frame using screws and thus are not as secure but are also much simpler to install, making them practical for interior doors where the lock is used simply for privacy rather than security.
I don't generally recommend the use of a warded lock to secure an exterior door, while it might befuddle the burgler armed with bump keys to attack a pin-tumbler lock the deadbolts are usually too short and the strike plates too weak to resist forced entry very long.(Though the same can be said of most common pin-tumbler locks as well.)
But for interior doors where privacy is the primary concern a warded rim lock is quite adequate. If you find yourself living in an old house you might just get stuck with them either from lack of finances to replace them or because a landlord simply can't be bothered with such a triviality. So lets go over the basics of their operation:
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>> No. 6985 ID: e880db
intredasting.
>> No. 6990 ID: cd49aa
Thanks for the info, man. I don't have much experience with warded locks. Except for what Master Lock tries to pass off as warded locks nowadays with their cheap padlocks.
>> No. 6991 ID: ddcf9f
>went to a meeting
>making locks
>see this thread
Fuckin' surreal man
>> No. 6992 ID: 06f96c
Thanks a bunch Ulfhunden.

I have a bunch of these in my house, now I can get keys and get them working again.
>> No. 6999 ID: 0a2b37
>>6990
>>6992

Glad to be of service gentlemen, I woke up feeling the motivation to do something that day and that's what I decided on. If you have any questions shoot them my way, This thread is just a rough draft.

>>6990

They are warded locks, They just also happen to be Master locks, it's like being born with downs syndrome, they can't help it. Warded Master locks are useful because they're highly weather-resistant and super-cheap, perfectly adequate for keeping kids out of your garden shed and if you lose your key and have to use the bolt cutters you're not going weep over the loss.
The quality of the lock should match the quality of your overall-security. No point in putting a high-quality lock into a flimsy door or vice-versa. Extremely high-security can be counter-productive too. Recently my lady-friend bought an electronic pistol safe, it was push-button only, having no redundant means to open it which was touted as a safety feature, but then her teen daughter shut the thing with her pistol and ammo in it before she had a chance to program the code. I told her if Customer service can't help her then she can work a hammer and pry-bar as well as I can. I haven't heard about it since so I assume the issue has been resolved one way or the other.


File 141983609541.jpg - (30.12KB , 289x320 , PC293026a.jpg )
6874 No. 6874 ID: f9c80b hide watch expand quickreply [Reply]
pic related

how can i cut a slot/groove into a bolt and nut without damaging the threads.
dont have a mill/drill press
1 post omitted. Click Reply to view.
>> No. 6876 ID: b5332d
>>6874
1. What the hell is this for?

2. What tools do you actually have or are willing to buy?
>> No. 6877 ID: f9c80b
>>6876

duct tape and a extension cord
>> No. 6880 ID: 8f9280
does the groove need to be like pic related?

You can do the nut with a saw. Vice would make life much easier.

For the bolt, if the groove can't go all the way through one side, I would suggest filing a flat face, using a prick punch to mark a series of holes, then go to harbour freight and buy a cheep drill press. Drill blind holes that almost just touch each other, then clean up with a file.

Lots of elbow grease. The threads will have burrs at the cutting edge, but if you run the cut nut over the bolt, the burrs shold be nocked off without cuasing further damage.

You'll want a vice. It is by far the most important thing, and a drill press. Baring a drill press, get an electric drill and just eyeball it since this is for roughing out stock and not anything percise. If you can't for what ever reason get these items, then you will be stuck with trying to make a bow drill. It works, but god is it slow and tiring.
>> No. 6886 ID: bdae0c
I'd say bolt in a vice, cut with a hack saw, file down with rat tail or flat as needed.

Then use die to cut the threads clean again. That way the damage that will be cased doing it on the cheap will be fixed. Small shitty tap and die kits go for like 20 dollars give or take.

All of these items baring maybe the vice can be bought cheap. If you can't get a vice then a couple of cheap c clamps could be used to improvise.
>> No. 6998 ID: bdc075
>>6886
Probably what I'd do as well

Sit on the couch with beer and clean the edges.


File 141298503256.png - (196.07KB , 749x472 , 1412718627060365.png )
6563 No. 6563 ID: e8f72b hide watch expand quickreply [Reply]
...

>Current projections for Mars-ready habitats put their weight at roughly 31 tons for a 4-person crew. With a torpor statis habitat, according to SpaceWorks, the same crew could be housed at a comparatively feathery 15 tons. Thus, the crew size of a Mars mission could be theoretically doubled without increasing the weight of the craft. A lightweight spaceship means less powerful rockets are needed to launch it, which further reduces fuel weight and cost.

>Of course, SpaceWorks mentions the psychological benefits of being asleep for 180 days instead of slowly descending into space madness. However, the chief advantage of deep sleep during space travel is likely cost and resource savings.

>As you might expect, there’s a ton of research that still needs to be done before astronauts can be made to hibernate for months at a time. RhinoChill has so far only been used in therapeutic scenarios—and most importantly, only here on Earth. It remains to be seen whether the technique can be used in orbit, but the potential savings on a flight to Mars could just be motivation enough for NASA to try it out.
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>> No. 6971 ID: 95f3d6
>>6959

If my time with KSP taught me anything, it's that we should assemble the final rocket in space. In orbit around earth, or maybe the moon. Not sure if the extra Delta V of a moon orbit justifies the complication.

I think at this point we wouldn't have any issue with the whole concept of assembly in space.
>> No. 6972 ID: 003f83
>>6970
>reusable rockets

we need a space elevator to the moon
>> No. 6981 ID: a6b004
>>6971
Stuff can be electromagnetically launched from the moon, there's no atmosphere. The moon has iron, aluminum, titanium, everything we'd need for really good alloys and metals except carbon, and we could do things there that we never could on Earth just because there's no environment to pollute.

Think about it: any gas, from pure O2 to uranium hexaflouride would just float away. There's no groundwater to pollute if your foundry explodes, or if your rocket fuel plant leaks.

As long as we shipped a few chemicals there, it would be the ideal place to build components, which then get put into orbit, assembled, and send Out.

Plus, with the moon being so stable tectonically, we could do a lot more underground. Farms, cities, etc. Better than the surface, actually, because of the radiation.
>> No. 6982 ID: aec606
>>6981
All that, and the gravity would be better to work in. It's what, 1/6th earth normal?

No fear of floating away, normal tools would work fine, and heavy stuff that would normally require a machine could be carried by hand (albeit carefully because mass.)
>> No. 6987 ID: 3681a8
>>6982
>All that, and the gravity would be better to work in. It's what, 1/6th earth normal?

Slightly less than that. A pound on earth is about .1 pounds on the moon.

This is cool, you can compare how much you'd weigh on different planets/moons and other celestial bodies.
http://www.exploratorium.edu/ronh/weight/

Surprising that Europa's gravity is so low and Neptune's is so high.


File 14198680465.jpg - (25.51KB , 425x481 , Spice_Must_Flow.jpg )
6881 No. 6881 ID: 13dbd1 hide watch expand quickreply [Reply]
Well, since piratebay is gone, what are some good torrent sites now?
23 posts and 9 images omitted. Click Reply to view.
>> No. 6924 ID: cd49aa
>>6921
Thirding.
>> No. 6926 ID: 885afe
>>6921
fourthing.
>> No. 6927 ID: cd49aa
>>6926
Seconding this fourthing.
>> No. 6928 ID: 49b231
>>6924
Seconding the thirding

>>6927
Thirding the fourthing.
>> No. 6931 ID: 5b49f3
Who still uses sourceforge? Get on github.


File 141454081531.jpg - (68.94KB , 240x300 , J528%20Lift%20off%20index%20small.jpg )
6640 No. 6640 ID: 802705 hide watch expand quickreply [Reply]
How do you operators feel about sugar rockets?
22 posts and 3 images omitted. Click Reply to view.
>> No. 6844 ID: db7b1c
>>6843
cant hear anything, why the fuck are they banging pans like baboons in the background?
>> No. 6855 ID: ca62af
>>6824
Because hybrid motors suck, unfortunately.
>> No. 6923 ID: 5f2bf8
>>6750
When I was younger, I was really into developing a smoke grenade mixture for airsoft, and I used sodium bicarbonate to slow the reaction. The smoke mixture is identical to the rocket candy fuel mixture besides the sodium bicarbonate.

All that being said, I was *really* into model rocketry when I was a kid, I built them to use the off-the-shelf Estes engines. You could get bulk engines for an order-of-magnitude cheaper at Toys R Us, but they stopped carrying them, so I kind of fell out of the hobby. I found the rocket candy recipe online not too long ago, and planned to get back into rocketry, but couldn't find a proven design for a nozzle. I have a hunk of Graphite that I planned to make it out of. If anyone is holding onto a nozzle blueprint, it would be most excellent if you could post it. What do you use as an ejection charge for sugar rockets?
>> No. 6929 ID: 06970f
File 142083230389.gif - (4.61KB , 565x294 , k-det4.gif )
6929
>>6923
http://www.nakka-rocketry.net/kappadx.html
>> No. 6930 ID: 06970f
File 142083234020.gif - (7.85KB , 730x365 , nozdwg1.gif )
6930
>>6923
http://www.nakka-rocketry.net/epoch.html


File 141108283813.jpg - (72.98KB , 640x427 , 1411065243985728.jpg )
6499 No. 6499 ID: e8f72b hide watch expand quickreply [Reply]
http://motherboard.vice.com/read/this-smart-super-stretchy-spacesuit-is-like-a-second-skin

>Spacesuits have come a long way since the 1960s. But they're still bulky spacewear, if you will, limiting the astronaut's range of movement. But, MIT researchers are working on a “second skin” spacesuit that is flexible, lightweight, and lined with “tiny, muscle-like coils.”

>“With conventional spacesuits, you’re essentially in a balloon of gas that’s providing you with the necessary one-third of an atmosphere [of pressure,] to keep you alive in the vacuum of space,” said Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT. “We want to achieve that same pressurization, but through mechanical counterpressure — applying the pressure directly to the skin, thus avoiding the gas pressure altogether. We combine passive elastics with active materials.”

>Newman has been working on a flexible, form-fitting spacesuit for the last decade. In that time, she and colleagues have engineered “active compression garments” that use “small, springlike coils that contract in response to heat.” The coils are built out of shape-memory alloy (SMA), which essentially creates a smart spacesuit that (after heating) “remembers” its engineered shape after being bent or deformed by an astronaut's body.

...

>“You could [also] use this as a tourniquet system if someone is bleeding out on the battlefield,” Holschuh said. “If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it.”

I wounder how they would account for accidental hardons?
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>> No. 6863 ID: 385f49
File 141914915587.jpg - (87.70KB , 448x650 , 0032.jpg )
6863
>>6860
>Isn't it enough that the suit is airtight and doesn't stretch and expand like a balloon?
Not really. Of course, you don't need as much space as you have in modern space suits, because they've been made for entirey different purpose - reliability, and reliability only.

Of course, this might be way to go, new materials and technology that will allow to secure both shape and pressure - which is what this design needs. But of course, two-layer structure is essential, and there will be nothing "skin-tight" in this design.
>> No. 6866 ID: 385f49
File 141915040184.jpg - (2.33MB , 3471x2311 , Expedition_16_suit_up.jpg )
6866
>With conventional spacesuits, you’re essentially in a balloon of gas that’s providing you with the necessary one-third of an atmosphere [of pressure,] to keep you alive in the vacuum of space
This is entirely wrong concept. You will need a protection from both vacuum and temperature, and also there are sun rays and micro meteorites. This is the difference between "space suit" and "pressurized suit". I'm not really sure if this confusion is intentional, but such design would be only useful for modern concept of "space tourism", which is actually just a "thermosphere jumping".

http://en.wikipedia.org/wiki/Advanced_Crew_Escape_Suit

http://en.wikipedia.org/wiki/Sokol_space_suit
Detailed technical specifications:
http://suzymchale.com/ruspace/sokol.html
>> No. 6871 ID: 68aa6b
>>6866
Correct. In addition to being a vacuum suit it needs to provide at least minimal protection against radiation and have a cooling system.
>> No. 6878 ID: 294081
  Man how sad is it that this technology has changed so little in so long...
>> No. 6925 ID: cfafa0
I can't wait for this:

>3 Our spacesuit design is finally coming together and will also be unveiled later this year. We are putting a lot of effort into design esthetics, not just utility. It needs to both look like a 21st century spacesuit and work well. Really difficult to achieve both.

https://www.reddit.com/r/IAmA/comments/2rgsan/i_am_elon_musk_ceocto_of_a_rocket_company_ama/cnfq5qf


File 142016118679.png - (157.08KB , 1291x2228 , Demons - lesser.png )
6899 No. 6899 ID: 5b9651 hide watch expand quickreply [Reply]
Working on getting my other laptop up to speed for daily use and the WiFi is driving me nuts.

Its running Ubuntu, which I can normally make do about anything, but this is a fucking mystery.

Last time I booted this thing, WiFi worked just fine.

So I start Wicd and connect to my access point. It authenticates fine and gets an IP. Then the internet works for about fifteen seconds. If I go to www.google.com say, it will start to load the page and about halfway through the connection will drop and I'll get a "could not connect to server" error.

If I ping my router at 192.168.1.1 right after connecting, it will ping fine for about 7 pings at ~40ms each, then go Destination Host Unreachable. Wicd however, still shows the AP as properly connected with no errors.

I've fixed plenty of issues where you couldn't connect to WiFi at all, but I've legit never seen one where the WiFi loses connection after a set time. The only thing that seems to change is that the AP signal strength will be 100% when I connect (laptop is right beside the AP) and after it drops the strength will be in the 60-70 range.

Wifi card going bad maybe? Never seen anything like this.

Or do I have a pic related in there somewhere?
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>> No. 6908 ID: cbf3af
>>6907

Its a refurb laptop. Originally from 2009 but rebuilt by some company online. I got it early last year.
>> No. 6909 ID: 39d4a6
>>6908
Do you have a USB wireless adapter to test?

>>6899
>If I ping my router at 192.168.1.1

Maybe try changing it to the 10.X.X.X address space? You never know.
>> No. 6913 ID: d4df2e
File 142027830092.jpg - (895.33KB , 3000x1688 , 1404192716621.jpg )
6913
Gonna second testing this with another wireless device. Get a cheap ass USB wireless adapter and try that. This will help determine if your crap is crap.

If it works, then your WiFi chipset is probably at EOL. Good thing is that you can pretty easily replace it in some laptops. Anyways, if you cannot connect to your home base, then try with some other WAP. If it still doesn't work, then something is wrong with your comp/OS and we can go from there. If it does work, then it's probably the router and we can check that out.

Which wireless chipset are you working with on your comp?

Also...
>using Ubuntu
Enjoy your Amazon spyware.
>> No. 6914 ID: 8f9280
>>6913
>derail into distro pissing match

oh god yes go get some #!
>> No. 6920 ID: 06a0fb
>>6914
#! best distro, all years.


File 141601266185.png - (234.49KB , 591x445 , CustomPCBuild.png )
6711 No. 6711 ID: e6f4f7 hide watch expand quickreply [Reply] [Last 50 posts]
Currently looking at options.

Budget: Less than $800 not including monitor.

No ASUS motherboards.

No Nvidia chipsets, please. Bad experiences with them. Would like a card that has HDMI options to use with TVs and the like.

Haven't decided Intel or AMD. Leaning AMD, but am open to using Intel is the price/performance of it in gaming is worth it.
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>> No. 6873 ID: 097fc9
>>6870
See that big opening on the motherboard mount piece? Back in the day when ever you need to change the CPU back plate you will have to dismount the motherboard to gain access to the under side. Modern cases now has a big opening so you can change the back plate with ease.
>> No. 6879 ID: 392726
Most airflow problems, IMO, have little to do with the actual wiring in the case and much more to do with wanting to stick too large and powerful components into a cheapass, too small a case, with no extra fans added.
>> No. 6890 ID: 7fcde8
>>6879

Someone didn't learn on computers with IDE or SCSI cabling.....
>> No. 6891 ID: 26a501
>>6890
This. Not everything was so easy and small as SATA cables.

IDE cables were fucking huge and to make matters worse few cases back then had wiring options. To make matters worse, most IDE cables were also long as fuck.
>> No. 6892 ID: 392726
>>6890
>>6891

I don't know about you two noobs, but when I was using ATA or IDE cables, I remember the case being pretty sparse inside. What were you doing where your 333 computer was overheating in 1997? Or where an IDE cable would choke off all airflow?


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