• 0 Posts
  • 20 Comments
Joined 1 month ago
cake
Cake day: June 6th, 2024

help-circle




  • No one has given a real answer yet, and I’ve worked with these before, so I’ll explain. The short answer is it has to do with the logistics of cooling something to near absolute zero.

    The main component of a quantum computer is a tiny microchip, maybe a few centimeters across. The big chandelier is for cooling and interacting with the quantum computer. (Compare to a desktop computer which has a small CPU chip but most of the computer is for cooling, powering, or otherwise supporting that CPU).

    Towards the center of the chandelier thing there is a mechanism called a “dilution refrigerator” which uses weird properties of liquid helium to cool the quantum chip to about 15mK above absolute zero. There are often other refrigeration techniques at work and the dilution fridge does the last step of cooling.

    The twisting golden tubes are microwave waveguides. Essentially they are wires that carry signals to and from the quantum computing chip. The twists are there because there is a lot of thermal contraction that happens when cooling from room temperature to near absolute zero, and the loops give the tubes some slack to contract.

    Not shown in pictures as often because it’s less exciting, but the whole chandelier thing is put in a big metal cylinder, and that cylinder is within another cylinder, like a Russian nesting doll. Sometimes there may even be a 3rd layer. The air gets pumped out of the cylinders so it’s a vacuum inside. The multiple layers of cylinders are needed because the black body radiation from the outermost layer (which will be at room temperature) would be too much incoming energy to keep the qubits cold enough.

    Also not shown is this whole thing is connected to an elaborate system of vacuum pumps, other refrigeration machines, usually a box of electronics for signal generation, and a classical computer (a standard desktop computer) used to control everything.

    Note that not all quantum computer types use this kind of chandelier thing, only ones that need the near-absolute-zero temperature, such as superconducting qubits (trapped ion, neutral atom, and photonic quantum computers use very different setups).









  • Honestly, if it’s just a small, personal project, just use common sense and take some basic precautions (e.g. use a firewall, use NGINX instead of serving Wordpress directly, etc.).

    Note that CloudFlare doesn’t protect you from everything either - it only provides some very specific services. A rudimentary level of caching images being the most common one a free account level would be able to use.


  • If the worst thing Apple ever did was sell some optional components no one needs to buy to use their core products for more than you think is reasonable, Apple would be a fantastic company.

    I’m not shilling a mega corp, I’m calling out petty bullshit. You’re the one making Apple look good by complaining about petty bullshit. Find something real to complain about.




  • WolfLink@sh.itjust.workstoPrivacy@lemmy.mlWhy don’t you like Apple?
    link
    fedilink
    arrow-up
    4
    arrow-down
    8
    ·
    edit-2
    27 days ago

    Sure, if I didn’t have 100 compatible chargers already from a variety of other products, and wasn’t willing to purchase 3rd party products, I’d have to buy a $20 adapter from Apple.

    Also, I just checked and the latest Pixel comes with a cable but not a brick, same as the iPhone. Also Google’s cheapest power brick is $25, so it’s actually worse than Apple.

    Got any real complaints?