https://docs.aws.amazon.com/whitepapers/latest/aws-fault-iso...

Normal AWS (`aws`) traces to `us-east-1`. AWS GovCloud (US) (`aws-us-gov`) is distinct, based in `us-gov-west-1`. AWS in China (`aws-cn`) is distinct again, based in `cn-north-1`.

The AWS European Sovereign Cloud is implemented as a distinct partition – `aws-eusc` based in `eusc-de-east-1` – so it has exactly as much in common with normal AWS as AWS GovCloud (US) or AWS in China.

https://datatracker.ietf.org/doc/html/rfc7725

https://en.wikipedia.org/wiki/TAMDAR

Observations definitely fell off a cliff as commercial air travel slowed to a crawl. In terms of impact, though… it turned out not to be a big deal.

> Aircraft reports suffered a 75% decline in numbers from mid-March to mid-April 2020; in May the number started increasing again. Despite the loss of data there is no clear signal in the forecast skill—partly because the skill shows considerable variability on daily, seasonal, and interannual timescales (Figures 3 and 4). …

> …

> Overall, we can find no evidence that the decrease in aircraft observations has handicapped numerical forecasts of extreme weather to an extent large enough to incur significant economic impact.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/202...

My last EV used 22 MWh over 6.5 years. That works out to 390W.

My solar array is located at high latitudes (northern Minnesota), the mounting angle isn't great, it's occasionally covered in snow, etc. In these conditions, I need 6.3 solar panels to produce 22 MWh over 6.5 years.

The area used by 6.3 solar panels -- enough PV to cover _all_ my EV's energy needs -- works out to be a parking spot large enough to fit the vehicle but not large enough to fully open any of the doors.

Comments URL: https://news.ycombinator.com/item?id=44474107

Points: 3

# Comments: 0

https://refurbished.minisforum.com/products/minisforum-s100-...

I have zero applications where a Pi5 makes more sense than either a mini PC or a large microcontroller.

> A station authorization shall be automatically terminated in whole or in part without further notice to the licensee upon:

> …

> (d) The failure to maintain 50 percent of the maximum number of NGSO space stations authorized for service following the 9-year milestone period as functional space stations in authorized orbits, which failure will result in the termination of authority for the space stations not in orbit as of the date of noncompliance, but allow for technically identical replacements.

https://www.ecfr.gov/current/title-47/chapter-I/subchapter-B...

_Congress_ can change this, but as written, Federal law compels the FCC to automatically terminate the authorization for failing to deploy half the satellites under 47 CFR § 25.161(d), just as they must automatically terminate the authorization when the license expires under 47 CFR § 25.161(b).

Most manufacturers bolt on IOT functions by dropping an off-the-shelf module onto their device-specific board. It's sometimes possible to replace the factory firmware with ESPHome, sometimes even using over-the-air updates. For example, AirGradient air quality sensors: https://github.com/MallocArray/airgradient_esphome

Even when it isn't possible to commandeer the factory IOT module, the fact that it _is_ a module is still useful, because it's almost always possible to inhibit or remove the factory module and connect your own instead. The factory IOT module controls and senses the device, so your replacement module can too, using the same pins. For example, an IOT air filter: https://github.com/mill1000/esphome-winix-c545#final-assembl...

Some devices are designed around multidrop communication busses. These are usually even easier, since the ability to join the bus is an intended design feature, even if the device you're using is not intended. For example, many Samsung residential HVAC systems: https://github.com/omerfaruk-aran/esphome_samsung_hvac_bus/d...

https://en.wikipedia.org/wiki/Dead_Hand

GFS and IFS are both medium-range global models in the class Google is targeting. These models are spectral models, meaning they pivot the input spatial grid into the frequency domain, carry out weather computations in the frequency domain, and pivot back to provide output grids.

The intuition here is that, at global scale over many days, the primary dynamics are waves doing what waves do. Representing state in terms of waves reduces the accumulation of numerical errors. On the other hand, this only works on spheroids and it comes at the expense of greatly complicating local interactions, so the use of spectral methods for NWP is far from universal.

S3 also supports more complicated cases where the entire object may not be visible to any single component while it is being written, and in those cases, `ETag:` works differently.

> * Objects created by the PUT Object, POST Object, or Copy operation, or through the AWS Management Console, and are encrypted by SSE-S3 or plaintext, have ETags that are an MD5 digest of their object data.

> * Objects created by the PUT Object, POST Object, or Copy operation, or through the AWS Management Console, and are encrypted by SSE-C or SSE-KMS, have ETags that are not an MD5 digest of their object data.

> * If an object is created by either the Multipart Upload or Part Copy operation, the ETag is not an MD5 digest, regardless of the method of encryption. If an object is larger than 16 MB, the AWS Management Console will upload or copy that object as a Multipart Upload, and therefore the ETag will not be an MD5 digest.

https://docs.aws.amazon.com/AmazonS3/latest/API/API_Object.h...

Rust inherits this from `pthread_detach()`:

       The detached attribute merely determines the behavior of the
       system when the thread terminates; it does not prevent the thread
       from being terminated if the process terminates using exit(3) (or
       equivalently, if the main thread returns).

The earth's crust floats on top of liquid rock. This matters at relevant length and time scales; in most places, these effects alone are on the order of millimeters per year. One reason why it's better to use NAD83 over WGS84 in North America is that NAD83 latitudes and longitudes move with the North American plate.

Positions _are_ relative, and the closer you can put your datum, the less drift you'll accumulate.

https://hal.science/hal-04287433v1

https://hal.science/hal-04287433/file/Version%20HALL.pdf

Secondhand can be viable too. Some of my "jellybean" EtherCAT terminals came from eBay. I won't get help from Beckhoff if they break, but given that I already have replacements on hand, I'm really not worried about it.

Beckhoff also lets you download almost all the development tools, runtimes, and PLC libraries without paying. In their words:

> Trial licenses can be generated in the TwinCAT 3 development environment (XAE) for many TwinCAT 3 functions for a validity period of 7 days. This can be repeated any number of times. An internet connection is not required for this. In this way, these TwinCAT functions can be used simply and cost-effectively in laboratory operations, e.g. in the education sector.

This is obviously useful for development and experimentation. It can also be an escape hatch in production if you need to substitute controllers. Beckhoff wants you to pay for what you use, sure, but their licensing scheme goes out of its way to avoid kicking you when you're down.

I have a construction project involving several buildings with overlapping infrastructure. Everything gets connected to EtherCAT as quickly as possible. Electric generation: solar panels, batteries, inverters. Energy management: branch circuit monitoring, weather forecasts, solar forecasts, load control for things like EV charging and water heating. HVAC: heat pumps, buffer tanks, circulation pumps, valves. Building automation: lighting, access control. I just add I/O wherever, connect over Ethernet, and glue all the signals together in software.

I wouldn't dare approach a project like this with Arduino.

https://github.com/willglynn/tempest_exporter

Their central web API is nice too (and the tool above can extract metrics from it) but the local, offline data access is what got me in the door. Tempest could shut down their services tomorrow without breaking my setup.

https://blog.rust-lang.org/2024/03/30/i128-layout-update.htm...

Note also that this involves LLVM, so clang < 18 had the same u128 behavior as Rust < 1.77/1.78.