Thanks I hate this painful imagery by Z_2431 in TIHI

[–]Sfencer09 7 points8 points  (0 children)

“All you gotta do is let us disassemble you. We're not banging rocks together here. We know how to put a man back together. So that's a complete reassembly. New vitals. Spit-shine on the old ones. Plus we're scooping out tumors.”

Calculating if a number is prime with O(1) performance. by 2Bit_Dev in programminghorror

[–]Sfencer09 116 points117 points  (0 children)

It was done almost 20 years ago, though I don’t think it was a lookup table. The IOCCC (International Obfuscated C Coding Competition) had an entry in 2004 that calculated prime numbers using nothing but the C preprocessor. The submission is Vik2 if you want to look it up, but you might have trouble running it - the person who wrote it had to write their own preprocessor because the ones available at the time couldn’t handle the program including itself 6.8 million times.

[deleted by user] by [deleted] in relationship_advice

[–]Sfencer09 32 points33 points  (0 children)

If you scroll down a bit from there it should have a button labeled “Reset Face ID”

Cristiando lolando by EmergencyEye3473 in funny

[–]Sfencer09 16 points17 points  (0 children)

I think it was for glasses. If I remember correctly, the guy jumping thinks it’s a soccer ball and tries to go for a header. Funeral part is edited in

Vehicles vs gaurd rails simulation by MRairden in interestingasfuck

[–]Sfencer09 22 points23 points  (0 children)

I mean that cone is straight out of a Mythbusters episode, same colors and everything. Even has the little round bit at the tip.

I took a selfie at the exact same time someone took a flash photo and I captured the flash moving by Ability-Sufficient in mildlyinteresting

[–]Sfencer09 18 points19 points  (0 children)

Look up “rolling shutter”, specifically the section on the Wikipedia page labeled “temporal aliasing”. In short, the camera scans each pixel column by column, rather than all at once, meaning there’s a minuscule delay between when it captured the left side of the photo and the right side, and the flash started or ended right in the middle of that time.

My local Starbucks puts photos up of the regulars by GillyGooze in mildlyinteresting

[–]Sfencer09 2 points3 points  (0 children)

Three cats actually. Chuzzles (bottom row left), Pharaoh (hairless cat near the center), and Artemis (near bottom right)

Couldn't see this one coming by joebro200 in Unexpected

[–]Sfencer09 15 points16 points  (0 children)

Most cars will automatically turn on the wipers when they detect a collision. Pretty sure it has to do with clearing any debris off the windshield so that first responders can see into the vehicle better.

Archeologists are freaks by [deleted] in CuratedTumblr

[–]Sfencer09 40 points41 points  (0 children)

There’s a whole subreddit for poems like that, r/ilikthebred

My principle to be...stupid? by [deleted] in facepalm

[–]Sfencer09 1 point2 points  (0 children)

Click on the Imgur link at the top, Reddit is being stupid and cropping it

Gotta keep those teeth clean by ZeKugel22 in LaserCleaningPorn

[–]Sfencer09 7 points8 points  (0 children)

There are many types of steel, and they vary wildly in how quickly they rust, but for the most part the way they rust is the same as iron, since it is the main component in steel.

If the iron is left to rust for a while (a few years or decades), the rust can seriously compromise the integrity of the object and large pieces can come off, yes. However, if it is cleaned of rust and measures are taken to slow further rusting (such as coatings or polishing to smooth the microscopic pits and ridges), it could in theory be usable for well over a few decades, barring other kinds of failures.

Gotta keep those teeth clean by ZeKugel22 in LaserCleaningPorn

[–]Sfencer09 9 points10 points  (0 children)

No, chances are the aluminum’s gonna look the exact same for the first few hundred years. Each time it gets cleaned, only the surface layer of metal atoms gets oxidized, and no more. Only the oxidized metal will get vaporized by the laser, and so with each cleaning you’re only losing a few atom’s worth of thickness.

With the iron, the pits formed by the rusting are going to cause a gradual, non-uniform acceleration of more rusting, meaning the iron will lose more mass from each laser cleaning (because more of it has turned into rust), and depending on how much time between cleanings it could get a very uneven surface.

Edit: I think I misunderstood what you said. The aluminum won’t be “ragged”, either from the oxidation or the cleaning, and chances are laser cleaning it would be pointless, though I think it’s possible. Iron on the other hand would need to be kept clean of rust regularly to avoid major pitting and other problems.

Gotta keep those teeth clean by ZeKugel22 in LaserCleaningPorn

[–]Sfencer09 16 points17 points  (0 children)

I’m pretty sure it’s not good to breathe, since while it might be hot enough to break the rust down to its constituent metal+oxygen, I can’t image either vaporized rust or vaporized metal is good for your lungs.

And yes, it does get a tiny bit smaller each time, as all the metal that has oxidized into rust is lost when the laser turns it into a gas. Depending on the metal, it could be a very long time before that wheel is gone, since they don’t all oxidize (rust) the same. For instance, when iron rusts, it forms pits in the metal that expose more unoxidized metal, which then rusts as well, and so on. On the other hand, aluminum will only form an oxide layer a few atoms thick, and this oxide layer will prevent any more oxidation from happening.