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Cake day: June 17th, 2023

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  • A semi related but enlightening (thought) experiment.

    There is a theory that our universe isn’t actually 3D is actually a projection/simulation on the 2D surface of a black hole (aka the big bang). If this were the case, then the practical differences would be almost nonexistent. The exception is the planck length. This is the smallest length that is meaningful. If our universe is 3D, we are extremely far from being able to measure effects anywhere close to the planck length. If it is 2D however, that length appears FAR bigger. It wouldn’t be that far below what our current gravity wave detectors can see.

    The effects of this would be similar to a simulation running near its limit. It would be the equivalent to floating point rounding errors.


  • That’s one of the things we are looking for with particle accelerators, like CERN.

    Quantum Mechanics is ridiculously accurate, within its domain. However, it doesn’t predict, or allow for General Relativity.

    GM is ridiculously accurate, within its domain, but doesn’t allow for quantum mechanics.

    Therefore we know both must be wrong (or at least incomplete).

    Unfortunately the overlap is when gravitational forces become significant on quantum scales. There’s 4 ways to study this.

    • We can pack a ridiculous amount of energy into a tiny space, in a controlled manner. This is the best method. We also can’t do it.

    • We can pack a ridiculous amount of energy into a tiny space, in an uncontrolled, brute force manner. We can then hope to get lucky, or do it enough to beat the odds. This is what particle accelerators like CERN do. We can’t control what hits when accurately, but we can do enough collisions that 1 in a trillion is useful, then sift through the data looking for it.

    • We can use tricks to ‘stretch’ the quantum realm. This method is limited, but interesting. Gravity wave detectors effectively do this. They can use a laser to create an effect quantum object measured in meters or more.

    • We can look for places where quantum gravity is dominant, and see what happens. This is what things like the web space telescope are good for. We can look closely at black holes, and neutron stars, and see what they do to space time. Unfortunately, we are also stuck with whatever the universe happens to have done.

    In short, the problem is being chipped at. It’s painfully slow, and buried in ever more complex maths, but it’s being done. I would love to see this “solved” in my lifetime. It’s unlikely, but could happen.


  • You can transmit something, but it has a noise added to it. To decode it, you need to send the readings to the other end, via normal means. Basically, the receiver can tell, in hindsight, that a message was sent, but only once its other half has been received via normal means. The best you can do is get a timestamp of when the message was sent, as well as a message channel that is impossible to intercept.

    The problem comes when QM meets relativity. With instant communication, you can send information into its own past. E.g. A and B are 2 planets. C is a ship, passing planet B at relativistic speeds. Planet A sends a message to B, over the FTL link. B then sends it to C, over a normal link. C, finally sends it back to A over FTL. Due to the ‘tilt’ of C’s light cone, the “now” of A-C is behind the “now” of A-B. This allows for paradoxical situations. The maths of Relativity implies that you can’t form a closed time loop like this. Such behaviours tend to imply some deeper rule, even if we haven’t found its cause yet.

    Quantum mechanics has a lot of strangeness. It also seems to play fast, but not loose with causality. E.g. objects can move backwards in time, but still obey causality. Others can be smeared over time space, but still collapse to a causality obeying state. Etc


  • cynar@lemmy.worldtoAsklemmy@lemmy.mlHome automation - why?
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    8 months ago

    Ironically, IKEA of all companies has done it right. Their smart lighting is price comparable to dumb lighting, and works out of the box. Even pairing an additional bulb to an older controller is fairly painless.

    Under the hood, however, they are using ZigBee. This means they are cross compatible. You’re not locked into their ecosystem.

    Basically, you can have something as simple as a drop in lamp bulb, that can be turned off or on with a little remote. If you want more capabilities, it will scale with your desires, including playing nicely with other brands.

    Most heavily advertised home automation is a steaming pile of shit. It’s mostly to try and lock you into their ecosystem and either sell your data, or show you adverts. Hobbyists can go DEEP. There is a useful middle ground however. It just gets quite buried in the noise.


  • cynar@lemmy.worldtoAsklemmy@lemmy.mlHome automation - why?
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    8 months ago

    Unfortunately, a lot of appliances have jumped on the IoT bandwagon, but have missed the wood for the trees. They all want you to use their own proprietary app to control it. This cripples the biggest advantage of IoT, synergies.

    A tumble dryer that you can turn on and off from an app is fairly useless. A tumble dryer that can sync its load with the other appliances, and the current solar panel output is a different story. Even with simpler setups there are synergies. Having a light pulse when the washing is done could be extremely useful to some people. Particularly if the appliance is in another part of the house.

    As for smart locks… The less said about them, the better. Unfortunately, the “S” in IoT stands for security. That’s fine for a lightbulb etc, but not for a critical door lock. It’s frustrating. I would love a decent smart, well made, door lock, with a viable open protocol. They just don’t exist yet.

    As for why a smart lock would be good? Dynamic access control. With a normal lock, if you give someone a key, they have full access, whenever. They can also copy your key, and so taking it back isn’t always reliable. A smart lock lets you authorise and de-authorise people on the fly. E.g. it works normally for you, but your mother in law’s login (keycard, dongle, app, fingerprint etc) sets off a warning on your phone. You might also want to let a delivery driver open the door, while watching them through a camera. Your package is now secured, and even the driver can’t get back to it.


  • cynar@lemmy.worldtoAsklemmy@lemmy.mlHome automation - why?
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    8 months ago

    In short, enlightened laziness.

    I can turn the bedroom lights on and off, from my bed.

    I can turn the bathroom light off, after my young daughter left it on, in the middle of the night.

    My livingroom lights colour shift, to keep my family’s sleep cycle in vague check.

    I can turn my heating down room by room, if it’s not needed. Conversely, I can preheat the house, on the way home.

    While the setup took a bit of prep work, it’s now highly reliable, and makes my life a lot easier.



  • cynar@lemmy.worldtoPeople Twitter@sh.itjust.worksKarens come to mind
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    8 months ago

    As a white person, I’m fine with jokes at my expense, so long as they are actually funny, and not delivered maliciously. This struck true, and doesn’t seem to be malicious.

    I would love a world where “racist” jokes are a non-issue for everyone. Unfortunately there are enough racists who hide behind “it’s just a joke”. Till then, I will continue to fight for equality.



  • One of the funnier ones is that the matrix actually did hacking right. It was also so quick you don’t notice it.

    When Trinity hacks into the power station, it’s legit. She checks the software version, which shows an out of date version. She then uses a known flaw in that version to reset the password.

    It’s the only bit of actual hacking in the movie. They obviously knew that geeks would be checking it frame by frame, so they actually did their homework on it.


  • Not all PIP are that bad. Unfortunately it’s mostly a final chance type situation. Most decent managers try and sort problems out long before it gets to PIP levels. When it happens, it’s a final chance to turn things around. It also formalises the evidence gathering that they tried to fix it, but couldn’t.

    Unfortunately, some companies abuse it. They also tend to be the ones with high staff turnover however, so it looks a lot common.





  • If you’ve not done so, look into replacing/getting replaced the electrolytic capacitors in the TV. They are one of the only parts that truly suffers from aging. By the sound of it, some of yours are on their last legs. If you replace them before they go completely, you can limit the damage. A failed cap can often cause damage to other components.

    The caps will generally have their value and tolerances printed on them. They are ¢ each, so it’s fairly cheap, parts wise.