I think Schneier wrote this well before quantum computers were a reality - did he miss something fundamental in regards to them? Quantum computers are relatively new but the theory behind them is nearly a century old.

*One of the consequences of the second law of thermodynamics is that a certain amount of energy is necessary to represent information. To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. (Stick with me; the physics lesson is almost over.)

Given that k = 1.38×10-16 erg/°Kelvin, and that the ambient temperature of the universe is 3.2°Kelvin, an ideal computer running at 3.2°K would consume 4.4×10-16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump.

Now, the annual energy output of our sun is about 1.21×1041 ergs. This is enough to power about 2.7×1056 single bit changes on our ideal computer; enough state changes to put a 187-bit counter through all its values. If we built a Dyson sphere around the sun and captured all its energy for 32 years, without any loss, we could power a computer to count up to 2192. Of course, it wouldn't have the energy left over to perform any useful calculations with this counter.

But that's just one star, and a measly one at that. A typical supernova releases something like 1051 ergs. (About a hundred times as much energy would be released in the form of neutrinos, but let them go for now.) If all of this energy could be channeled into a single orgy of computation, a 219-bit counter could be cycled through all of its states.

These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.*

I’m not a physicist but quantum particles were still considered to be matter the last time I checked.

Looks solid!

Sorry, I’ve been trying to login at least a couple times a week but haven’t seen any notifications that there were new posts. I tried to watch the video but it says the r/DIY community is private. Just based on your description though I was wondering if maybe you need to balance the fan blade. I’ve had that problem with a few cheap fans and was able to get them to run about 90% more quietly by just eyeballing the blades and bending the one that looked “off” back into place. I think Mattias Wandel has a video somewhere on how to get really scientific about it if you want to get down to zero vibration.

Thanks! They only use it for paper, cardboard, and really thin boards, like less than 1/8". Sheet metal would definitely have a sharp edge and the little crescent moon chips it makes would be absolute hell if they ever were to get spilled in the carpet or lawn.

Thanks! They’re not quite as convenient to move around as those foldable lawnchair things everyone uses but they’re far more comfortable.

I added a sink to it over the weekend, now there’s a place to rinse out paintbrushes and wash hands. It’s hooked up to a garden hose, so there’s no hot water. There’s a twist timer at the end of the hose so it will shut the water off automatically after 2 hours in case the 3 year old leaves the sink running. The drain just goes out the back corner and into the lawn. I’ve been dumping my buckets of paint water in the side yard for several years now and it hasn’t killed my grass yet so it should be OK.

It works perfectly! I was able to leave a 6 and 3 year old out there with 50 little paint bottles completely unattended for 45 minutes while I made dinner last night. There’s paint all over the place in the playhouse but none got in their hair or in our house so I call that a win.

Thanks!

I was wondering about this also when I tried to sign up to lemmy.world on Monday and it seemed like it just timed out while I was trying to register and login. It looked like they were getting some traffic but it shouldn’t have been enough to bring everything to a crawl like that.

Did you make the catio too? I was thinking about making one of those with an exit from a basement egress window.

I bet she loves that, good work!

Thanks!

Thanks! I might have used it myself once or twice when I didn’t feel like cleaning up after the jigsaw…