On Using an 'O'-ring Part II

After a useful piece of advice on the RTCUK group that said you should clip to an 'O'-ring on your bridge rather than directly onto the bridge, I started to do exactly that. The rationale was that a carabiner will wear in the same place and abrade the bridge quicker than a ring that will wear uniformly all round it. Fair enough.

Well yesterday I was putting up a high hammock and had set up a Y-rig with two doubled ropes off the bridge. One was on my ring, but the other was clipped straight to the bridge. Because each leg was attached to anchors quite far apart, the tie-in points migrated to the ends of the bridge - but the directly-clipped one went beyond the bridge-end fittings.

This is not a good thing. Lesson learned. I'm buying a second 'O'-ring.

Tree Chilling

Thanks Jos for the great picture! An oak that can't help but make you happy.

My Funeral

At my funeral, this is the piece to which everybody leaves.

Mastodon - Open Source Decentralized Facebook/Twitter Alternative

Read all about it.

"Mastodon is a decentralized social network that uses standard interoperability protocols and is completely [FOSS]. What this means is that anyone can run a Mastodon server, and the users of those servers can talk to each other. More than that, non-Mastodon servers are also part of this network if they conform to the same protocols. This means that Mastodon is more future-proof than Facebook or Twitter: Even if Mastodon-the-software falls out of fashion, the network can be simply continued by other interoperable software. You don't have to tear out your entire social graph to have all friends migrate to something new if that happens. Furthermore, Mastodon allows self-determination and control. When you run a server, it's yours. Your rules, your community, hosted on your hardware... you don't depend on anybody, definitely not on a [Silicon Valley headquarters]."

from BoingBoing

Find me at @collapsibletank@mastodon.social

Nadal

Rafael Nadal looks like Tom Cruise with his face smushed against a window.

Think Twice

There are a number of great maths channels on YouTube, such as Numberphile and Mathologer - but the most beautiful and elegant is Think Twice, where smart and smooth animation visualises otherwise complex formulae or theorems. For example, here's the derivation and properties of the Dragon Curve.

(Mr Puzzle has a nice review of some laser-cut puzzles including a Dragon Curve one here.)

Ancient Beech in Ill-considered Leggings

A return to a tree in Danes' Wood I'd only seen out of leaf, and which was hard to find with the wood in its summerwear. Turns out it's a beech and I can't tell my arse from my arbour.

Surprisingly tricky, requiring quite a lot of repositioning in order to get a good enough line for several of the re-pitches, but each stage was quite short.

The tree branches considerably all the way up, so there are a lot of choices to make, but once at the top you can move from place to place relatively easily with a long lanyard to play with. Also - great for limbwalking.

Inevitably I'd climbed about one metre higher than my rope would allow for a return to ground, and because of being too lazy to climb up and move my anchor point, I ended up using my lanyard to unclip from my zig-zag and drop to earth with my foot ascender still attached. Getting cramp in your supporting leg while trying to detach from a foot-ascender is both hilarious and agonising in equal measure.

Summertime

Aw yiss... 

Noah Lee - "Julie-O"

The whole of this is great, but Noah Lee's piece is really special.

BETTER Dancing in Movies

There's a video doing the rounds this week called Dancing in Movies, and it's proving to be impossible to avoid. 1.5 million plays on Vimeo. Virality huh... But it's no good. The tracks he chose are agonisingly undanceable and it doesn't match satisfyingly with any of the actual dancing, much of which is amorphous. It's just random clips of dancing with a weak musical backing.

This one, on the other hand, from three years ago, is an absolute classic. Every clip is achingly skillful, the track (Uptown Funk) is the most leg-twitchingly danceable track ever produced, and the dancing actually fits the rhythm of the song, which you'd think would be fundamental to a project of this type.

Raising Sophisticated Young Ladies

Shaldon Ness

A beautiful day on Shaldon Ness this afternoon. First up a handsome Copper Beech on Ness Drive with the sun coming through the leaves.

This one is definitely a contender to house a couple of hammocks. Fairly quiet and easy to hide in, but very leafy so not much view; which is a shame because in winter you can see right along the coast. Then up a tall oak that overlooks the car park in one direction, but in the other direction - open sea! This is fantastic.

Trees at the top of cliffs are a real treat. I was up a different tree on the same headland last week and a helicopter flew past beneath me!

Today, I was waving at paddle-boarders. There's not a lot of cover in this oak...

Really special.

Five Old Blokes and a Million Kids

AC/DC in their still-rocking dotage. Worth it if only for the jumping crowd at 2m27s.

Shaldon Ness climbing

Too much new growth for a hammock these days, sadly. Still lovely though.

The Poor People's Campaign

This is a good introductory (to me at least) piece on the Poor People's Campaign. I wanted to say something like "and so it begins", but it has been actively running for five weeks with little in the media to show for it. This article asks why.

It ends with this excellent photo-essay.

DEET and Climbing Ropes

There was an interesting conversation at the RTCUK Sleepover about DEET maybe degrading climbing ropes. It was scary enough to make you think twice about risking Lyme's or a nasty fall. After all, as a solvent DEET will melt plastic and denature your sunglasses, camera and so on.

I couldn't find anything definitive online, but everything you can find points to this quote from a report which now seems to be unavailable:

“Summary of Nylon, PET and Spectra Chemical Resistance to DEET

Many climbers have in the past worried about the effects of accidentally spilling bug repellent on their climbing ropes. The following is the result of preliminary testing of deet and other bug repellent chemicals.

Samples of nylon, polyester, and spectra were submitted for chemical resistance testing for DEET (N,dimethyl-m-toluamide). The three samples were immersed separately in “CUTTER” and “OFF” brand insect repellent for a period of twenty-four hours at room temperature. “OFF” contains 95% Deet (N-dimethyl-m-toluamide) while “CUTTER” contains only 7% Deet and probably some oil based solvents as well. The results of the testing indicate no loss of strength as measured by tensile strength retention in any of the three samples.

There was one interesting anomaly that occurred only in the case of Nylon and the “CUTTER” brand insect repellent. As mentioned before there was no loss of strength for any of the samples but here there was a 25% increase in the elongation and a decrease in modulus. This basically means that a rope made entirely or mostly out of Nylon may become “rubbery” with a significant amount of exposure to “CUTTER” or other insect repellents with large amounts of oil based solvents.

However, with regard to the chemical in question, DEET, there appears to be no effect on any of the physical properties of the three samples. Hence as “CUTTER” contains only 7% DEET the change in the Nylon elongation and modulus must come from the other solvents in the product. It is suggested that if a rope has significant amounts of Nylon to use insect repellents with 95-100% Deet instead of ones with some Deet and large amounts of other oil based solvents.

Please keep a major factor in mind in regards to this study/testing. The only two brands tested were OFF and Cutter and were specific formulas of those brands. So we can’t necessarily say that all bug repellent products with DEET will not harm the stated materials. Other brands and other formulas could contain a substance other than what was in the two formulas tested. In other words, it is probably safe to say DEET itself has no effect but there can be other chemicals in other repellents that may.”

— Honeywell Performance Fibers

Personally, I'm taking this as permission to not worry. The most up-to-date forum discussion about this I could find was this one, and there seem to be no accounts online of rope failure after DEET contact. Your mileage may vary, but for me avoiding the relative certainty of again having to extract gangs of voracious parasites from my nethers beats the theoretical risk of equipment failure.

Hit Like a Girl - Yokoya

Yaaaaaaaaaaaaaaaay!