Talk:Spider silk
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[edit] Inaccurate text
Removed the following block of text since I think it's inaccurate:
- By comparison of size and density, spider silk is 5 times much stronger than steel and possesses an elastic property, thus giving it a very high energy-to-break ratio. In fact, the biopolymer structure of the silk is so strong, it is true to imagine the likes of a strand the size of a pencil being able to easily stop and hold a fast Boieng747 commercial jet in flight! To date, spider silk is the strongest known material to man and synthetic materials cannot hope to even come close. The protein- and biopolymer-based material differs across the over 35,000 species of spiders, and is easily recyclable.
Mark Foskey
"The proteins in the silk are complex molecules of amino acid. " Correct me if I'm wrong, but isn't all proteins complex molecules of amino acid? Bong 11:47, 8 Nov 2004 (UTC)
I have a few questions about the subject:
- How thick is spider silk and what is the volume of a spider web of, for example, about 20 cm in diameter? What I'm getting at is: what if a spider is starving, how much of its body mass can go into making a web?
- If the builing of a web si destroyed, is that a huge loss of body mass for most spiders or are their metabolism set up to build a few in a row wihout ingesting food. (I'm sure it depends on species, but does someone have an idea?)
- How long does a piece of spider last last in good conditions? How long do spiders use them for? I'm sure it depends on what it is meant for, but is it possible to have more information about each use? Can a spider in a good location keep the same web for months or are all varieties of silk meant to degrade after a relatively short time?
I also second the question on the spider web discussion page.
Eje211 16:56, 13 October 2005 (UTC)
- With regard to the "how much mass does a spider use up when creating a web" question, this is what I calculated:
- According to this page, the density of spider silk is 1.3 g/cm3, and according to this page, the diameter of spider silk is 0.15 microns, and in this research they used a silk fiber with diameter of 2 microns. Let's be generous and use the 2 microns estimate. A typical web is roughly circular, is 10 cm across, and includes maybe 5 lines that run along a diamter, and maybe 20 that act as rings. Let's estimate then that the total length of silk is about (5*10 + 10*(3.14*10))cm = 364 cm. The volume of this is then (3.64 m)*( 3.14 * (1*10-6m)2 ) = 1*10-11m3 ! That's not a whole lot of volume, when you consider that a spider has a volume of, say, 1cm*1cm*1cm = 1*10-6m3. It doesn't seem that the mass used up in creating a web is very much compared to the mass of the spider itself. The amount of bio-energy used up to make all that protein and spin it out and weave it is possibly more significant.
I removed the 'citation needed' from the first paragraph, based on the above, another page I found, and math: Even using the biggest number I have seen, 7 μm, as a thread diameter:
Weight of a strand long enough to encircle the earth = Thread density * Thread cross-sectional area * Earth circumference
= δt * At * RE
= 1.3 g/cm3 * ( π * (3.5 μm)^2 ) * 6378.137 km (equatorial)
= 1.3 g/cm3 * 3.84 × 10-11 m2 * 6378.137 km
= 1.3 g/cm3 * 245.45927 cm3
= 319 g
But, since we only started with one significant digit, the best answer is "about 300 g". Certainly less than 400 g though. --208.99.195.54 18:14, 18 May 2007 (UTC)
[edit] More Inaccurate Text
I didn't remove any text, but there is a statement that Nexia has given up research on producing artifical spider silk, and this is not true. Nexia, in collaboration with the University of Wyomming, is producing mass quantities of goat milk that is already enriched with the spider proteins (ADF 3 and ADF 4).
You may have read an old souce... the goats owned by Nexia did indeed produce the silk dope that they were hoping for; however, they found it impossible to spin the liquid into actual threads of silk. The silk dope requires the spinnerettes to properly weave and fold the silk so that it has the correct properties. Nexia, without enough funding, simply could not work it. The project was dropped, and the goats were killed. PETA (people for the ethical treatment of animals) was upset by the incident, claiming that the slaughter of innocent goats who HAD DONE WHAT THEY WERE EXPECTED TO DO, was inhumane, especially seeing as how genetically altered goats are illegal to sell as a food product, so their death was a waste of life with no benefit to humanity. Of course, to defend Nexia, I must agree that taking care of goats for several years after the funding had been cut and simply waiting for them to die would be an economical hardship on such a business. Nexia is not very good at resource management. -Tillie
I do have a problem, however, with the following: "Spider silk, normally that of the golden orb spider, is occasionally harvested and spun into usable textiles. Due to the difficulty of the process, the resulting fabric is invariably extremely expensive, and is generally utilized in fine couture." I have never heard of "fine couture" but I think "haute couture" may be what is meant. However, seeing as there are very few haute couture houses and spider silk is not massed produced, you would think there would be something, somewhere in the world to agree with this text. I cannot find anything, and I believe this information is incorrect and should, perhaps, be removed. I would do it myself, but perhaps instead someone could find a source? -tillie —Preceding unsigned comment added by 68.8.32.139 (talk) 10:04, 26 October 2007 (UTC)
[edit] Do all spiders make such hard silk?
I occasionally have spiders (small ones) in my house, but I can ruin their webs with a simple wave of my hand (though I try not to, since they eat insects). Do only some species of spiders make strong silk, or are those webs only weak because they are so thin (I can sometimes not even see them under certain lighting conditions, surely an advantageous trait for trapping insects) and they would be tough indeed if woven into a thicker thread or fabric?
The thickness and strength of spider silk varies between spider species. It also depends on the type of silk being produced, dragline silk is strong and rigid, while eggsac silk has a much lower strength, allowing the young to emerge.
Typically Argiope and Nephila (St andrews cross and Banana spider respectivly) dragline silks are studied for structural applications. These are both large tropical spiders, the larger size makes them easier to work with, and they produce strong webs to catch larger prey. In contrast lycosa (wolf spiders)dont create an orb style web, and are largely a hunting spider, So they produce less types of silk, none with the dragline qualities of an Argiope or Nephila
[edit] Thickness and density of silk strand
How thick is a strand of silk, and what density does the material have? IMHO, this is more interesting than the factoid about the weight of a strand around the earth, which answers none of the questions. —The preceding unsigned comment was added by 83.181.2.44 (talk) 07:30, 5 December 2006 (UTC).
[edit] Pencil?
A strand of spider silk with the thickness of that of a pencil (roughly) is so strong that it is believed to be able to stop a Boeing 747 aircraft in flight.
Can anyone give some references here? How much force is needed to stop a 747 in flight? What type of 747(the weight of the 747 differ by type: Boeing 747#Specifications)? Stopping it meaning be able to just stop it, or actually hanging it up and supporting its weight? It is very strange to see a sentence like this since the force required varies with different stopping time(i.e. deceleration) and is not a good example. Normally wouldn't it be a sentence like a strand of silk with the thickness of X can support a weight of Y? MythSearchertalk 08:09, 20 June 2007 (UTC)
[edit] Unclear meaning
"Argiope argentata has five different types of silk, each for a different purpose:[2][3]
dragline silk: Used for the web's outer rim and spokes, as well as for the lifeline. As strong as steel, but much tougher. "
What is the difference between strength and toughness? Am I missing a subtle distinction?DBSouthwell 09:44, 28 July 2007 (UTC)
In case anyone is still wondering, strength is a measure of how much stress at failure point, toughness of how much work to get there —Preceding unsigned comment added by 131.215.220.132 (talk) 21:55, 11 April 2008 (UTC)
