Technology
Use bread to remove crayon marks from the wall

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Hackszine reader Keith Hanshaw sent in a tip for a safe way to remove scribble marks from your walls. Just grab a piece of bread, roll it into a tight ball, and start rubbing. It looks like it takes a bit of elbow grease, but it’s a cheap and chemical free way to clean up after the kids – Link.

12 thoughts on “Use bread to remove crayon marks from the wall

  1. The usual theory, after you get past the “RF waves are somehow being amplified by water and bone” stage, is that you hold the remote a little higher when you’re in the experimental condition than when you’re in the control condition. This is true for both videos: original tests had them with arms outstretched, whereas when they held the remote to the head, the elbow was bent and the remote was, as you saw, at head height.

    It’s been my informal experience that holding the remote higher does help, though I’ve not gone to the edge of remote control range to try to do anything particularly sophisticated by way of an experiment.

  2. I’m a physicist and this seems a bit hokey (By physicist I mean Ph.D Student). What Ntolnry said seems most likely, by increasing the height by half a foot, not only is the line of sight better, but the RF waves can bounce off of Earth’s surface a bit to complete the distance.

    The unlikely theory that is more cool is as follows: Most remote key fobs operate at up to and around 1 GHz. This corresponds to a wavelength of ~30cm. Whenever you have a confined cavity on the order of an integer multiple wavelengths (here 30, 60, 90cm,…), a very strong resonance can build up due to constructive interference as it bounces around. A little more or less, and a smaller resonance builds up. So theoretically, without knowing much about the skull’s ability to reflect 1GHz waves or the dielectric effect of the brain and its fluids, it seems possible that the skull (~20cm average) is enhancing the signal marginally.

    It’s worth actually jotting down some notes to see if it is possible, but more easily, just try it out. I’ll risk looking like a fool to see if it could work.

    -James M

  3. I’ve known about this for years. It creeps me out every time I do it, but I can tell you that it does work.
    If you’re too far away, you can jump up and down and point it in every direction and it still won’t work. Then you touch it to your head and your car beeps. I use the chin technique without the open mouth thing. Works great.

  4. I’m hearing a lot of people say this is legit. Here’s a simulation model and explanation of why it works. From the article:

    We found that holding the key to the chin greatly increased the currents flowing in the hand and chest regions compared with other positions, these currents then radiating a signal roughly four times as powerful as with the key in other positions.

  5. This is partially legit…

    My understanding is that the real way this works is by reorienting the transmitter….

    The signal emits from the transmitter at a right angle to the “face” of the remote. When you “point” the car remote at the car acutally the majority of the signal goes up and down NOT forward.

    If the battery is low and signal is weak by reorienting the remote vertically this transmits the signal outward and more efficiently…this is mimicked by holding it to your chin but I’ve found that the same signal “amplification” happens if I hold it upright away from my body.

    Give it a shot yourself…..no chin involved.

  6. The following is a repost of my comments on LifeHacker, as well as some additional information clarifying some of the misconceptions written here:

    You’re not amplifying the signal, nor are you using your body as a bigger antenna. You’re tuning (detuning?) the antenna to a slightly different frequency.

    The planar antennas used in hand-held devices (keyfobs being the most ubiquitous example) are designed for a frequency range that is slightly off of the desired frequency. The intent is they will be held when used, and the user’s body will detune the “manufactured” frequency to the desired frequency.

    Receiver sensitivity is heavily based upon a specific frequency being used, but frequency tolerance of mass-produced items is sloppy, at best, typically towards the range of “We need a beluga whale-sized body next to this antenna to tune it correctly”. Placing the keyfob against your head detunes the transmitter even more than just being in your hand, most often towards the desired frequency. The receiver sees a frequency that is closer-than-usual, which increases its sensitivity, hence you get a longer range.

    Reorienting the transmitter can actually make things worse, depending upon how you orient it. The strongest signal comes (roughly) out of the loop antenna in the same plane as the board the antenna is etched on (the edge of the fob, not the face). Holding the keyfob up to your mouth or head by lifting your hand straight up will actually reduce the signal strength reaching the car (unless you twist the fob so that it is parallel with the ground again).

    Fob frequencies are typically in the 315 MHz range, not Ghz, due to FCC regulations on output power within that band and the lack of licensing requirements. As you approach the GHz range, the water in your body is going to have an effect on signal strength (decrease).

  7. Haha wow. This is big among German car owners. My friend, who at the time had a VW Passat, showed me this for my Audi A4. I’d say I use this daily. My friend now has a Mini and he probably uses it more than I do. We were standing right behind the car and he could not even unlock the trunk with the remote.

    Most people I know hold it under their chins.

  8. I’ve done this and it works, but I’ve not strenuously tested it. An alternate-theory for those of us willing to reach out to alternate theories… Is the idea that the brain is not a storage organ, but a receptive organ. I.e, a transmitting-receiving antenna, not a hard drive. (Perhaps, both.)

    Although a bit far-fetched, the truth is the brain is really very complicated and we don’t know 100% of how it works. The article said that it helped explain concepts like deja vu, coincident thoughts, instinct, and other stuff like that.

    Perhaps what these wild thinkers need to do is more keyfob testing to lend support to their brain-mind theories.

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