1. Home
  2. UK Do-It-Yourself Forum
  3. OT: Fantastic engineering ..

OT: Fantastic engineering ..

Hi All,

I was in Mums back garden this morning and there was the most amazing feat of engineering on display in the form of a spiders web. ;-)

It had about a 1m horizontal span on the top guys and about .5m down to a plant at the bottom. If you examined the anchor points closely they were multiplied over maybe 2 or 3 points. The 'web' itself was very concentric, about 30 cm diameter but the actual circles were no more than 2mm apart (nothing was getting past this baby!).

The builder ( brown / white and about 1" long) was sat in the middle waiting for his breakfast ;-)

It semms a shame that although very strong (in a materials sense) it is very weak and be so easily wrecked by us just brushing past (all that effort and no breakfast) ;-(

Is the spider the ultimate d-i-yer? (how many of us could build something that large and that quickly without a crane!) ;-)

(waits for Mary with stories of Bees putting up her shed) ;-)

All the best ..

T i m

Reply to
T i m
Loading thread data ...

Probably a female cross spider.

It's how they get the thing started/anchored that amazes me.

I flaming well hope not. There are many other more suitable newsgroups. Why not bog off to those.

Reply to
Chris Bacon

Almost certainly /Araneus diadematus/, the cross spider, so called because it has a cross shaped white marking on the back of its abdomen. Not at all rare in the UK. They can do webs of at least a metre, this depends on windage, it would appear, they sit on one vantage point and let the silk drift downwind to another. From there on in, it is relatively simple. A bit of penduluming about and the radial fibres are in place. Then the orb is run, and the spider generally takes the optimal position to get to the prey, the centre. Typical behaviour is to eat the web in the evening and renew it the next day. I once, while waiting for my o-level (that dates me) results watched AD putting up a web. It didn't take more than an hour. As for the engineering fibroin is stronger than steel. The spiders use things called spinnerettes to produce their silk, and use it for various other purposes including wrapping their prey and encapsulating their eggs.

A dirty trick I played on a spider was to use a water spray on its web to photograph it. The water dried off quickly, though and it was having afternoon tea when I next passed the web.

There are three basic types of spider, orb-web as in AD, sheet-web as in Tegenaria atrica, the house-spider (The big hairy brown ones which dash across floors causing some women to freak, the poor thing is harmless) and the wolf spiders which hunt actively. For spiders their eyesight is exceptional and the edge up to their prey until they are in range and pounce. ISTR there is also a spider which fires silk ont its prey to immobilise it before it moves in for the kill. Certainly arachnids are survivors, but not all are as adept at web-making.

John Schmitt

Reply to
John Schmitt

Horrible way they feed isn't it?

I just hate those butchers shop BBC Natural History programmes that purport to be both educational and scientific. What they are really, is quasi autonomous, religious broadcasts for viewers to be indoctrinated into the belief of evolution.

"Each to his own gods" I suppose (if I may be forgiven for quoting a little of the bible.)

What gets me with these marvels is the way they deal with stretching and strain. There are nodes built into the strand that act like coil springs. How did they accidentally mutate to invent that? All of them.

I should just love to hear that old fart Attenborough try to explain it. Once again the devil is in the detail there too. As he merely states facts; logic and reasoning are nothing to do with him (or the BBC.)

One poster here asked about the spider that shoots its prey. It doesn't squirt gossamer or whatever the proper name for it is called. That is reserved for human mutants that get bitten by web spinning spiders.

(Don't ask.)

I believe the species you are referring to, fires hairs at its prey, stunning it with utric acid, the same stuff as in nettles.

Reply to
Weatherlawyer

See also Bolas Spider as in

formatting link
't think you get any in the UK, but ISTR Durrell reporting them on Cyprus.

Andy

Reply to
Andy Champ

You could indeed.

A news group should be mainly on topic but does also attract a community of contributors, whereby other topics are occasionally discussed.

The whole thing becomes rather boring if it is just a simple Q&A list, so having a broad range of contribution adds to the interest.

This one was marked as OT from the outset.

In comparison with some NGs which contain only spam and complete nonsense, this one strikes a good balance between valuable content and contribution from those with the experience of life.

In that sense, Mary has a lot to contribute. Some of it may be distinctly "alternative", but I think that that is to be applauded. Nobody is asking you to agree.

You have the option not to read posts on a given thread or from a given author but not to deny that to others.

Reply to
Andy Hall

Oh dear.

Creationists usually do (quote the Bible).

Reply to
Bob Eager

More likely her :-)

Oh, it's no problem, she'll make another very quickly.

I was standing by an internal gate in our garden yesterday and felt something brushing my bare arm. I moved and looked round but I was nowhere near the gate frame so I moved back and felt it again. I reliased that it must have been a web and looked more closely, I was right. They really are VERY strong. This web was undamaaged by my brushing against it.

It must have just been brushing against the hairs on my arm. Which brings me to another Interesting Fact. An Official one.

The lightest touch which can be felt by a human is a bee's wing falling onto the cheek from a distance of 3cm.

None of us.

Sorry to disappoint you, I typed the above before getting as far as this :-)

Honeybee comb is very strong in terms of containing large weights of honey and brood but in mechanical terms wasp comb (the inside of a wasp nest) is much stronger.

Mary

Reply to
Mary Fisher

Any one of them is welcome in my house. I hate flies.

Dave

Reply to
Dave

A recent tabloid reports that 50% of Americans are convinced that the world suddenly came into being 10,000 years ago. Show them a fossil or two and they go all quiet. :-)

Reply to
Andy Luckman (AJL Electronics)

In my experience (and I've met a fairly major exponent of creationism) they just says that the fossils are fakes, manufactured to support the evolutionists' claim!

I did once go to a lecture by him (I actually organised it, but *that's* another story). very high-tech, slick and convincing - except to the group of academics in the audience...

Reply to
Bob Eager

The big fault with the creationist argument is that it answers nothing; who made the creator, or the maker's maker? Thus it can only appeal to the sort of person who when as a child asked 'why?' was content to be answered with 'because I said so'. Not something of appeal to the curious or the DIYer.

Reply to
DJC

Scary - they're gradually receding back to the 18th Century....

Reply to
Steve Walker

This is from someone posting as "*lawyer" ?

Reply to
Andy Dingley

Even more so if they decide they want to rejoin the Empire.

Reply to
Andy Hall

And maybe spiders build their own houses to keep away from estate agents! ;-)

T i m ;-)

Reply to
T i m

Why is it scary? They're not threatening you.

Mary

Reply to
Mary Fisher

The Americans are threatening the whole world - including me and you and the OP.

Reply to
Geoffrey

Not because of creationist beliefs.

Reply to
Mary Fisher

It's a smallish step from "My God created the universe", to "My God created the universe for his believers".

Reply to
Ian Stirling

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.