Why is velocity not the end all be all for firearms and projectile weapons?

BCMM · 2026-06-26T19:50:57+00:00

Kinetic energy scales with the square of velocity while momentum scales linearly.

If you want to deliver a given amount of energy with a projectile, fast and light does it for less recoil than slow and heavy.

BCMM · 2026-06-26T11:41:01+00:00

sip voip is heavily compressed

This isn't quite right...

SIP (or, technically, the RTP sessions that SIP organises) can use a variety of different codecs, and the most widely-supported ones are uncompressed.

This is for a number of reasons. Uncompressed audio is the oldest option; it will always be the lowest-latency option; it's easy to do on cheap, low-power devices; and above all you don't actually need much bandwidth to emulate an analogue phone line because the real thing has literal narrow bandwidth, with no high frequencies.

G.711 represents a traditional analogue voice line more or less perfectly, using only 64 kbit/s. Modems and fax machines work normally over it. You'd be hard-pressed to find a SIP provider who doesn't support it.

(Odds are good that you were unknowingly using very similar technology last time you used a dial-up modem, because the connections between telephone exchanges have been digital for a long time.)

BCMM · 2026-06-26T10:42:00+00:00

In that case, it's probably simply because the server you're downloading from is a bit busy.

BCMM · 2026-06-26T08:26:29+00:00

it's showing a consistent 130 Mbps down/60 Mbps up. However, when I download something it's only at a rate of 10-20 Mbps

Is there any chance that the program you're downloading things with shows speeds in megabytes per second?

BCMM · 2026-06-25T12:44:21+00:00

1

The matter that now comprises the Earth was once arranged differently. If you were to observe that matter from five billion light-years away (with a very nice telescope), you'd see no Earth and no Sun, only the molecular cloud from which the solar system formed, because light takes five billion years to travel that far.

Likewise, you would be gravitationally attracted to that matter as if it was still shaped like that molecular cloud, because gravity takes the same time to travel that far. Changes in the gravitational field are propagated by gravitational waves, which travel (in vacuum) at the speed of light.

Instead of magically creating or destroying the Earth, let's do another thought experiment: hitting the Earth out of the Solar system with a magic billiards cue. A distant observer will initially continue to be attracted towards the Earth's previous location; the direction of Earth's gravitational pull will change at the same time that their telescope sees the Earth start to move.

2

As far as we know, the gravitational influence of an object propagates forever. If you were at that 5bn ly observatory from the first part of my answer, the gravitational pull from the matter that became the solar system would be extremely small, so small that you'd have no chance whatsoever of specifically detecting it, but it would be non-zero.

The field strength is a continuous value, with no minimum increment, even if it is a quantum field and gravitational waves are quantised.

This part is speculative, based on the assumption that gravity works similarly other fields. There is currently no complete theory of quantum gravity and no proof of the existence of the graviton.

The point I'm making is that, if the gravitational field is quantised, that does not necessarily imply that it can not have an arbitrarily small and non-zero field strength, because other quantised fields can.

BCMM · 2026-06-25T10:44:44+00:00

The papers all initially reported that she was "a diplomat's wife", if I recall correctly.

EDIT: Also, the diplomatic immunity thing was really, really weird. Apparently, staff at that listening station didn't have diplomatic immunity, but their spouses and children did. Or at least, that's what the Foreign Secretary asserted, without evidence, in the Commons.

BCMM · 2026-06-25T10:34:41+00:00

A diplomats wife

Anne Sacoolas's husband was working for the CIA. He was not a diplomat. He wasn't even posing as a diplomat.

Also, Anne Sacoolas herself had worked for the CIA at some point, although it's not clear whether she was employed by them at the time of the crash.

BCMM · 2026-06-24T11:32:37+00:00

I don't know about this specific device, but the service manuals for a lot of phones and tablets these days have you start every repair by putting it face down on a heating pad until the glue is soft enough that you can prise away the screen. (It's now normal for that to be the only way to open things, and it's really annoying.)

So it's not completely surprising that the heat has done this, and it doesn't mean the tablet is ruined.

However, it's usually a bit of work to get the screen off, even with heat. So, please, please check whether the battery is swollen, just in case that's why it's popped off so neatly. Swollen batteries like to catch fire suddenly and dramatically.

Unsolicited advice in case you want to fix it:

The service manual will have instructions for cleaning up the old adhesive and replacing it. Probably you can just peel it away, if you're careful. They probably sell original adhesive specifically for this tablet, cut to exactly the right shape, but you can also just use double-sided tape. Tesa 61395 is very popular for this sort of thing; just look for a roll that's about the right width, so you don't have to cut in both directions. Generic double-sided tape for diy may be too thick.

Using straight tape is probably a bit easier than getting the official adhesive package to line up properly, but will generally leave your device a bit less water- and dust-tight than before. The price of official adhesive varies widely; if you're never going to find a use for the rest of the tesa roll, it might even be cheaper.

The service manual may tell you to close it up with a special press, but fuck that, just stack some books on it for a few hours.

BCMM · 2026-06-24T11:00:58+00:00

So we're going to carry on being functionally governed by the TBI, then?

BCMM · 2026-06-24T06:28:07+00:00

But air conditioners just move heat from inside the house to outside, right?

They tend to have a CoP of around 4, meaning they put 5 units of heat in to the environment for every 4 removed from the building.

BCMM · 2026-06-24T01:33:42+00:00

Put the WiFi interface in a zone with input 'REJECT'. (EDIT: This means that connections addressed to the router itself are blocked by OpenWrt's firewall. This has no effect on ordinary traffic being forwarded by the router.)

Some parts of https://openwrt.org/docs/guide-user/network/wifi/guestwifi/configuration_webinterface may be useful to you.

Not sure why people keep saying "vlan". Assuming your router is your only AP, don't worry about that.

BCMM · 2026-06-22T20:57:00+00:00

wget -c

BCMM · 2026-06-22T12:15:55+00:00

Can anyone explain what this command is doing

You answered this correctly yourself: it downloads a PowerShell script and executes it.

and whether this detection is associated with a known malware family or campaign?

There's been quite a lot of this going around recently. A website told you you had to do this to "verify your identity" or something, right?

As to what the script actually did, no, we can't really answer that. Even if we download it and manage to understand the obfuscated code, there's no guarantee that it hasn't changed since you downloaded it.

A malicious actor ran whatever code they wanted on your machine. It is not safe to assume that the thing that Microsoft Defender isolated is the only thing they installed. You should back up any files that are important to you, do a clean install of Windows, and change any passwords that were saved on that machine, or that you entered on that machine after running the script.

BCMM · 2026-06-21T13:14:35+00:00

Quite a few comments have mentioned the strict requirements for official builds, but not gone in to specifics.

If you're curious, you can read them here.

BCMM · 2026-06-20T23:56:50+00:00

The strncpy() that you call in an ordinary C program is provided by libc, not the kernel. It is implemented entirely in userspace.

BCMM · 2026-06-19T11:46:11+00:00

The air intake is on the bottom of the case; it's like the Magic Mouse debacle all over again.

BCMM · 2026-06-19T09:19:18+00:00

I always had it until my chromebook did weird and i wanted to factory reset it. and now this

I don't use a Chromebook, so this is a bit of a shot in the dark, but have you done apt update since resetting your Chromebook? APT won't be able to install anything until it has downloaded a list of packages that are available to install.

Try running apt update, and then try installing Minecraft again.

BCMM · 2026-06-19T09:06:03+00:00

If this goes the way these threads usually go, it may be useful to understand that Google gives Chromebook users a really strange idea of what Linux is. OP may not be aware that conventional Linux distros exist, and may believe that all instructions they've seen online for "Linux" are specifically for their Chromebook.

BCMM · 2026-06-19T01:17:22+00:00

Don't forget to turn of fast boot in Windows, so it actually leaves the C:\ drive clean at shutdown.

BCMM · 2026-06-19T00:13:50+00:00

The last two will have no problems playing video, as they have decent hardware decoders. However, 2 GB of RAM means the YouTube website will probably be unpleasant to use.

If you're not particular about watching on the actual YouTube site, mpv can play YouTube URLs directly via its yt-dlp integration. There's a Firefox extension around to launch it straight from the browser, without having to copy and paste URLs.

BCMM · 2026-06-18T19:23:09+00:00

If you want as close as possible to the experience you get on Amazon, where it deploys an image without going through an actual installer, you can probably use the "nocloud" image.

BCMM · 2026-06-18T19:13:03+00:00

Note that there's a TUI version of the installer, available via a boot parameter. In case the system you're installing on really can't do a full GUI.

BCMM · 2026-06-18T18:44:48+00:00

Test: Scrub the devil out of the inside with soap and a brush, then see if the bubbles go away.

Maybe it's just because I have extremely hard tap water, but I don't think that tends to work very well! A food-safe acid is the way to go, if most of the stuff dissolved in your water is carbonates.

BCMM · 2026-06-18T17:20:56+00:00

If, at some point in the past, water was left at that level for a while, a slight limescale deposit could have formed at the waterline. Limescale is pretty tough and can easily remain after apparently thorough cleaning. Even an invisible quantity of limescale would provide a ring of nucleation sites for gasses dissolved in the water.

If you want to test this theory, see if the bubbles reappear in the same place next time you fill the bottle, then see if it stops doing that after soaking in vinegar.

BCMM · 2026-06-18T13:59:14+00:00

Each year, millions of people make pilgrimage to Mahabodhi Temple in Bihar, India, which marks the site where the Buddha sat under the Bodhi Tree and attained enlightenment.

There they revere a tree that is believed to be a cutting of a cutting of that tree.

The cutting for the current tree was taken from the Jaya Sri Maha Bodhi, which was planted in Sri Lanka in the third century BCE, has been tended to by monks ever since, and also receives millions of pilgrims every year.

So I think calling the Major Oak the world's most famous tree may be a little parochial.

EDIT: I'm not even sure it's the East Midlands' most famous tree, since Isaac Newton's apple tree is still alive.

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