Can I Unlock Other People's Cars With My Remote?

iStock/dobok
iStock/dobok

Jason English, our esteemed editor, wonders, "How many other Camrys would my remote unlock? Is it really 1:1, or is there a chance my fob would open a Camry in Phoenix or Toronto?"

When you push a button on your car remote or garage door opener, a radio transmitter inside sends a signal containing a numeric code to a receiver in the car (or in the garage). When it gets the signal, the receiver tells the car (or the garage door controls) to lock or unlock (or open or close)—or whatever it's supposed to do given the button you pushed.

When remote garage door openers first came out in the 1950s, the transmitters in the remotes sent out a single signal. This was all well and good as long as you were the only person on your block with a garage door opener. But as they became more common, you could open any garage you wanted, because all remotes worked on the same signal. A security breakthrough came 20 years later when DIP switches—sets of eight manual electric switches packaged in a group and attached to a printed circuit board—were added. By setting the eight switches to a certain arrangement inside both the transmitter and the receiver, you had some control over the 8-bit code that they shared. The DIP switches could provide 256 possible codes. So while some security was provided, areas with lots of garage door remotes were still prone to code doubling and people opening up their neighbors' doors.

Early remote entry systems for cars were slightly more advanced. The system for each car had a unique code set by the manufacturer and used by that car's transmitter-receiver pair alone. The ratio really was 1:1. Just as my car lock or yours wouldn't open for Jason's key, our receivers wouldn't have responded to his transmitter's signal. These systems had their own problem: while the codes were unique to their cars, the same code was transmitted every time you used the remote. A radio transceiver called a "code grabber" could be used to intercept, store and retransmit the code later on. It was like having your key stolen and copied, without you knowing, while you were putting it in the keyhole and opening the door.

To combat the problem, manufacturers began using rolling codes (or hopping codes) in the mid-1990s. Instead of using a single fixed code, these newer systems use a set of rolling codes that change every time the remote is used. Now when you use the remote, the transmitter sends the current code to the receiver (most systems use 40-bit codes or longer, allowing for more than 1 trillion different combinations). If the receiver gets the current code, it responds; if not, it does nothing. The transmitter and receiver then "roll" the code using the same pseudorandom number generator (PRNG). When the transmitter sends the current code, it uses the PRNG to create a new code and remembers it. After receiving the current code, the receiver uses the same PRNG with the same original seed (the number that initiates the PRNG) to generate a new code. Using this method, the transmitter and the receiver generate matching sequences of codes and are synchronized (and, of course, all the information that's transmitted is encrypted).

What if you press a button on the remote while you're away from the car, generating a new code on the transmitter and desynchronizing the system? The receiver forgives your human error and accepts any of the next X valid codes in the code sequence (the number of "look-ahead" codes the receiver accepts varies among manufacturers). Push the button one too many times, though, and the receiver will ignore the remote and you'll have to resync the system.

Modern remote keyless entry systems are pretty secure, but there is a slight chance Jason could open another Camry if he wants to walk up to one and press the unlock button on his remote (assuming it uses a 40-bit code) one trillion, ninety-nine billion, five hundred eleven million, six hundred twenty-seven thousand, seven hundred and seventy-six times, running through all the possible codes his remote could transmit until one works (assuming he can hit the button once every second without taking any breaks, he'll need just shy of 34,842 years to do so). He'll also have to hope that the Camry he's trying to open has a receiver that uses a 40-bit like his remote, and isn't a newer model that might use a 66-bit code with 7.3 x 1019 possible codes.

Why Do Fruitcakes Last So Long?

iStock
iStock

Fruitcake is a shelf-stable food unlike any other. One Ohio family has kept the same fruitcake uneaten (except for periodic taste tests) since it was baked in 1878. In Antarctica, a century-old fruitcake discovered in artifacts left by explorer Robert Falcon Scott’s 1910 expedition remains “almost edible,” according to the researchers who found it. So what is it that makes fruitcake so freakishly hardy?

It comes down to the ingredients. Fruitcake is notoriously dense. Unlike almost any other cake, it’s packed chock-full of already-preserved foods, like dried and candied nuts and fruit. All those dry ingredients don’t give microorganisms enough moisture to reproduce, as Ben Chapman, a food safety specialist at North Carolina State University, explained in 2014. That keeps bacteria from developing on the cake.

Oh, and the booze helps. A good fruitcake involves plenty of alcohol to help it stay shelf-stable for years on end. Immediately after a fruitcake cools, most bakers will wrap it in a cheesecloth soaked in liquor and store it in an airtight container. This keeps mold and yeast from developing on the surface. It also keeps the cake deliciously moist.

In fact, fruitcakes aren’t just capable of surviving unspoiled for months on end; some people contend they’re better that way. Fruitcake fans swear by the aging process, letting their cakes sit for months or even years at a stretch. Like what happens to a wine with age, this allows the tannins in the fruit to mellow, according to the Wisconsin bakery Swiss Colony, which has been selling fruitcakes since the 1960s. As it ages, it becomes even more flavorful, bringing out complex notes that a young fruitcake (or wine) lacks.

If you want your fruitcake to age gracefully, you’ll have to give it a little more hooch every once in a while. If you’re keeping it on the counter in advance of a holiday feast a few weeks away, the King Arthur Flour Company recommends unwrapping it and brushing it with whatever alcohol you’ve chosen (brandy and rum are popular choices) every few days. This is called “feeding” the cake, and should happen every week or so.

The aging process is built into our traditions around fruitcakes. In Great Britain, one wedding tradition calls for the bride and groom to save the top tier of a three-tier fruitcake to eat until the christening of the couple’s first child—presumably at least a year later, if not more.

Though true fruitcake aficionados argue over exactly how long you should be marinating your fruitcake in the fridge, The Spruce says that “it's generally recommended that soaked fruitcake should be consumed within two years.” Which isn't to say that the cake couldn’t last longer, as our century-old Antarctic fruitcake proves. Honestly, it would probably taste OK if you let it sit in brandy for a few days.

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What’s the Difference Between Crocheting and Knitting?

djedzura/iStock via Getty Images
djedzura/iStock via Getty Images

With blustery days officially upon us, the most pressing question about your sweaters, scarves, hats, and mittens is probably: “Are these keeping me warm?” If you’re a DIY enthusiast, or just a detail-oriented person in general, your next question might be: “Were these knitted or crocheted?”

Knitting and crocheting are both calming crafts that involve yarn, produce cozy garments and other items, and can even boost your mental well-being. Having said that, they do have a few specific differences.

To knit, you need needles. The size, material, and number of those needles depends on the project; though most traditional garments are made using two needles, it’s also possible to knit with just one needle, or as many as five. But regardless of the other variables, one or both ends of your knitting needles will always be pointed.

While crocheting calls for a similar long, thin tool that varies in size and material, it has a hooked end—and you only ever need one. According to The Spruce Crafts, even if you hear people refer to the tool as a crochet needle, they’re really talking about a crochet hook.

crotchet hook and garment
jessicacasetorres/iStock via Getty Images

Part of the reason you only use one hook brings us to the next difference between crocheting and knitting: When crocheting, there’s only one “active loop” on your hook at any given time, whereas knitting entails lining up loops down the length of your needles and passing them between needles. The blog Darn Good Yarn explains that since each loop is attached to a long row of stitches, accidentally “dropping” one off the end of your needle might unravel the entire row.

Of course, you have a better chance of avoiding that type of manual error if you’re using a knitting machine or loom, which both exist. Crocheting, on the other hand, has to be done by hand. Since machines can create garments with extremely small stitches, some knit clothes can be much more lightweight or close-fitting than anything you’d be able to crochet—and knitted clothes can also be mass-produced.

When it comes to what the items actually look like, crochet stitches characteristically look more like knots, while knit stitches seem flatter and less bulky. However, materials and techniques have come a long way over the years, and now there’s more crossover between what you’re able to knit and crochet. According to The Spruce Crafts, socks and T-shirts—traditionally both garments that would be knitted—can now technically be crocheted.

knitting needles and garment
Sedan504/iStock via Getty Images

And, believe it or not, knitting and crocheting can even be used to depict complicated mathematical concepts: see what a crocheted hyperbolic plane, Lorenz manifold, and more look like here.

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