The Origin of Henge Monuments

The following is a comment I posted on mathstodon.xyz:

My personal theory for the origin of henge monuments and stone circles is that they evolved from the rituals performed by seminomadic people during the mesolithic when they returned to their summer camp site in the spring (or to their winter camp site in the autumn). All they find left of their previous home is the circle of wooden posts which held up the walls and the circular drip trench outside them. They repair the posts where necessary and then construct the framework of a conical roof above the posts and cover it and the walls with hides. They also clear out any foliage from the drip trench and redig it where necessary. They then go around and tend to the graves of those who died on previous visits to that camp. At the end of the season they dismantle the roof and pack up the hides and take them with them to their alternate camp site. After thousands of years of this, the people settle down at a permanent camp site, but they keep up the rituals ("because that is what we've always done!"). After a few more thousand years of rivalry between neighbouring families you end up with something like Stonehenge.

Although I haven't seen this theory mentioned anywhere, it does seem to explain several of the key features of henge monuments: the circle of wooden posts (stone posts only came later); the circular ditch outside the posts; the association with graves; and the association with processional ways.

This idea was partly inspired by memories of a childhood visits to an excavated Iron Age famstead on the North York Moors, near where we lived. The farmstead consisted of three or four round-houses of which only the base of the stone walls and central hearth-stones remained. The excavators had scooped out the drip-trenches around the walls, leaving only the entry path in front of the door-ways. As a child, I was fascinated by the thought that I was running in and out of the door-ways in the same way that children must have done two thousand years before.

Books

I am currently reading:

• The Buried Giant by Kazuo Ishiguro
• Doomsday Book by Connie Willis
• The Sorcerer's Apprentice by David Bronstein and Tom Fürstenberg (a chess book)

Simula 67 as a successor to Algol 60

From "Software Engineering: As it was in 1968" by Brian Randall:

In the more rarified ALGOL world in which I moved, 1968 was something of a watershed. The IFIP ALGOL Committee (Working Group 2.1) which had been set up following the publication of the original ALGOL 60 Report, met in Munich not long after the Software Engineering Conference. A week-long debate of remarkable intensity culminated in a majority decision to approve the ALGOL 68 report that had been prepared by van Wijngaarden, Mailloux, Peck and Koster (41). In response, a renegade group (of which I was a member) produced a brief Minority Report (18), in which we stated that "it will be required from an adequate programming tool that it assists, by structure, the programmer in the most difficult aspects of his job, viz. in the reliable creation of sophisticated programs. In this respect we fail to see how the language proposed here is a significant step forward". My own recollection in fact is that several of us felt even then that the recently proposed SIMULA 67 Common Base Language (12) came closer to our ideal, and would perhaps turn out to have at least as much impact as an officially promulgated ALGOL 68.

I have known a long time (mainly from the writings of Edsger Dijkstra) about how in 1968 the Algol Committee split over the decision to approve van Wijngaarden's Algol 68 language, with a significant minority issuing their own report saying it was too complex to create reliable software with. I had always assumed that the minority would have preferred something like Wirth's Algol W, but from what Randall says above they might have actually gone for Simula 67. Now that would have been something. It would probably have brought forward the flourishing of object-oriented programming by over a decade

How to connect to WH-1000XM3 Headphones from Ubuntu 20.04

The Bluetooth connection to WH-100XM3 headphones from Ubuntu 20.04 can be a bit hit and miss. This seems especially so if you use the headphones on more than one machine. Here is a command line session record of me using bluetoothctl (the commands I entered are shown in underlined bold):

$ bluetoothctl
Agent registered
[bluetooth]# scan on
Discovery started
[CHG] Controller E0:D4:64:02:D3:88 Discovering: yes
[NEW] Device 94:DB:56:18:25:5D LE_WH-1000XM3
[CHG] Device D8:FC:93:42:60:A7 RSSI: -35
[CHG] Device D8:FC:93:42:60:A7 TxPower: 10
[bluetooth]# devices
Device 8C:EA:48:5B:E5:D3 [TV] Samsung AU7100 43 TV
Device D8:FC:93:42:60:A7 IVYSAUR
Device 94:DB:56:18:25:5D LE_WH-1000XM3
[bluetooth]# connect 94:DB:56:18:25:5D
Attempting to connect to 94:DB:56:18:25:5D
[CHG] Device 94:DB:56:18:25:5D Connected: yes
[CHG] Device 94:DB:56:18:25:5D Name: WH-1000XM3
[CHG] Device 94:DB:56:18:25:5D Alias: WH-1000XM3
[CHG] Device 94:DB:56:18:25:5D Modalias: usb:v054Cp0CD3d0422
[CHG] Device 94:DB:56:18:25:5D UUIDs: 00000000-deca-fade-deca-deafdecacaff
[CHG] Device 94:DB:56:18:25:5D UUIDs: 00001108-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 0000111e-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 94:DB:56:18:25:5D UUIDs: 7b265b0e-2232-4d45-bef4-bb8ae62f813d
[CHG] Device 94:DB:56:18:25:5D UUIDs: 81c2e72a-0591-443e-a1ff-05f988593351
[CHG] Device 94:DB:56:18:25:5D UUIDs: 931c7e8a-540f-4686-b798-e8df0a2ad9f7
[CHG] Device 94:DB:56:18:25:5D UUIDs: 96cc203e-5068-46ad-b32d-e316f5e069ba
[CHG] Device 94:DB:56:18:25:5D UUIDs: b9b213ce-eeab-49e4-8fd9-aa478ed1b26b
[CHG] Device 94:DB:56:18:25:5D UUIDs: f8d1fbe4-7966-4334-8024-ff96c9330e15
[CHG] Device 94:DB:56:18:25:5D ServicesResolved: yes
[CHG] Device 94:DB:56:18:25:5D Paired: yes
Connection successful
[CHG] Device 94:DB:56:18:25:5D RSSI: -54
[CHG] Device 94:DB:56:18:25:5D Name: LE_WH-1000XM3
[CHG] Device 94:DB:56:18:25:5D Alias: LE_WH-1000XM3
[WH-1000XM3]# exit
$

If the connection fails then you might need to remove the LE_WH-1000XM3 entry from the device list by entering remove followed by its MAC addess, for example: [bluetooth]# remove 94:DB:56:18:25:5D, and then rerun the scan and connect commands.

Otter

On my morning walk this morning I saw an otter (Lutra lutra). It was under the Great Western Railway bridge at Kennet Mouth, Reading. I think this is the first wild otter I have ever seen (at least I don't recall having seen any on our holidays in the Lake District, Pennines or the Isle of Arran when I was young).