5 ms·

Spider Silk Can Halt a Train

54 points by geeknik 14y ago

packetslave 14y ago
Former vice president Gore spoke at Google a couple of weeks ago (promoting his new book). One of the research projects he mentioned was "spider-goats", goats that are genetically engineered to secrete spider silk along with their milk. Some details in a news article here: http://www.guardian.co.uk/science/2012/jan/14/synthetic-biology-spider-goat-genetics http://www.guardian.co.uk/science/2012/jan/14/synthetic-biol... Given the value of the silk (and presumably the difficulty in mass-farming spiders), this seems like an attractive idea -- as long as the scientists do the math right and don't end up with spiders the size of goats or something.
- trafficlight 14y ago
  Look on the bright side, we'll have a new sport: Spider Goat Jousting.
- smegel 14y ago
  Sounds like an unacceptable risk to me
  - eksith 14y ago
    Exact line used in criticism of vaccines, air-travel and in-vitro fertilization. All new technology carries unacceptable risk... until they don't. But that's why science needs a constant feedback loop to improve understanding and safety. We can't make safe what we don't understand.
    - marvin 14y ago
      He was making a joke about the risk of goat-sized spiders.
      - Djehngo 14y ago
        I don't think drawing attention to the fact the comment wasn't short sighted, merely inane will gather much more sympathy for the poster.
        adlpz 14y ago
        It might be interesting to introduce you people to the concept of humor.
        nrser 14y ago
        the joke here is that there are no jokes. that's what makes it funny.
- nasir 14y ago
  Having the silk liquid along with the milk is not enough to produce the solid silk. Spiders physical action in turning that liquid to solid is indeed another important part of that. Probably they should produce 8 legged spider goats!
habosa 14y ago
http://what-if.xkcd.com/18/ http://what-if.xkcd.com/18/ So can AK-47s.
- ateev 14y ago
  hahaa good one
- pyre 14y ago
  | air rifle fires [...] at a muzzle velocity of | 100 meters per second | The GE Genesis Series I locomotive [...] travels at | around 45 meters per second | If you bounce a single BB off the front of the | locomotive [...] you slow it down by about a foot | per day Why is everything in meters per second, then we jump to using feet all of the sudden? Isn't this just asking for conversion errors? :P
  - Deestan 14y ago
    > Why is everything in meters per second, then we jump to using feet all of the sudden? Metric is easier to do calculations in, while imperial is used for the "layman terms". The intended audience is mainly american, and feet are more familiar to them than meters.
    - lucian1900 14y ago
      But that's precisely the sort of practice that causes conversion errors. Non-metric units should only ever be used in addition to the metric ones, in parentheses, if at all.
      - Avshalom 14y ago
        If you're trying to stop a train with a BB gun conversion errors are not going to be your primary worry.
  - dbaupp 14y ago
    It's more poetic than "30 cm per day" or "a third of a metre per day".
minopret 14y ago
What about the materials and structure of a train car - can they sustain instantaneous force required to stop a speeding train? RRRIP! Oops, maybe not.
- NamTaf 14y ago
  They mention 300kN in the article, and in the design of trains that isn't a lot at all. For example, the AAR [1] standards require a railway vehicle to take up to 1.8x 1560kN longitudinal force - that is, the force imparted down the length of the train through the couplers in to the body structure - without causing bulk yield [2] of the body material. A second design requirement is for the body structure to take 4450kN 'collision' force without exceeding the ultimate strength of the body structure material. Other design criteria include, for example, crash protection of the driver's cabin if it's a locomotive where the drivers sit at the very front, so that part's often very strong and rigid as it needs to preserve a 'survivability space' for the drivers. For passenger cars, the body structure tends to have a lot of strength against longitudinal loads in order to combat the phenomenon of climbing. That is, in a railway collision with passenger cars, as the vehicles ride in to one another, there is the tendency for one to pop up/down and try to 'ride up/down' on top of/under the one in front. [3] This was demonstrated rather tragically in a particular accident (I can't find its name, sorry) where old wooden passenger vehicles did this. Their comparatively strong underframe simply sliced through the comparatively weak cabins like horizontal blades and caused huge fatalities. This is because old passenger cars used to basically be flat-top wooden vehicles with a cabin placed on top, so the body structure was very strong compared to the weak cabin. Since then, passenger vehicles must be specifically designed not to climb up on one another and do that. So really, in the sense of railway design, 300kN is minimal, especially when placed longitudinally down the length of the vehicle structure. They are far weaker against lateral collision so I guess if you ever want to cause a huge railway accident, hit a train side-on rather than end-on. [1]: Not the standards themselves, as they're not publically available - https://www.aar.org/Pages/Home.aspx https://www.aar.org/Pages/Home.aspx [2]: By 'bulk yield' I mean yielding over a significant portion of the structure. This is a legacy of the AAR standards originally being targeted towards hand calculations, where you couldn't easily inspect every particular section of every particular beam but rather you calculated it as a whole. With the advent of finite element analysis you can now do that, so it's permissible to see slight yield-levels of stress in certain small parts so long as the overall section as a whole remains under it. [3]: This will give a brief example of anti-climbers on rail vehicles: http://www.oleo.co.uk/products/rail/anti-climbers http://www.oleo.co.uk/products/rail/anti-climbers
ateev 14y ago
call the spiderman :)
p1mrx 14y ago
Anything can halt a train, if you put a lot of it in one place.
pyre 14y ago
| We were surprised to find out that the webbing | was portrayed accurately. They are forgetting that in the movie the strands of web were not all connected together. They had Spiderman at their center, holding on to them. It would seem that his body and/or his grip on the web strands would be the weakest link in trying to resist the force of a train.
- maxerickson 14y ago
  There's also some issues with conservation of mass. Poor Peter would at least be thirsty after all that web shooting, if not wildly hungry.
RyanKushner 14y ago
This is related to biomimicry (using nature as the inspiration for design). If you're interested in learning more, I helped start a local group: http://bayareabiomimicry.org/ http://bayareabiomimicry.org/ - Ryan
phreeza 14y ago
The article is a bit misleading in that it states that a spiders web could stop the train. The paper is clearer in this respect. Of course it should say the fictional web in Spiderman could stop the train, if it were made of the material of the actual spiders web. They assume a thread diameter of 5mm, as opposed to probably about .1mm in a real spiders web.
- sageikosa 14y ago
  My take on Spider-Man stopping the train was that the first several anchor points failed as anchor points in the web/anchor/train system (they underwent systemic collapse due to loads past their design tolerances). Therefore, Spidey increased the number of anchor points to more even distribute the load.

54 points by geeknik 14y ago

Former vice president Gore spoke at Google a couple of weeks ago (promoting his new book). One of the research projects he mentioned was "spider-goats", goats that are genetically engineered to secrete spider silk along with their milk. Some details in a news article here: http://www.guardian.co.uk/science/2012/jan/14/synthetic-biology-spider-goat-genetics http://www.guardian.co.uk/science/2012/jan/14/synthetic-biol... Given the value of the silk (and presumably the difficulty in mass-farming spiders), this seems like an attractive idea -- as long as the scientists do the math right and don't end up with spiders the size of goats or something.

trafficlight 14y ago
Look on the bright side, we'll have a new sport: Spider Goat Jousting.
smegel 14y ago
Sounds like an unacceptable risk to me
- eksith 14y ago
  Exact line used in criticism of vaccines, air-travel and in-vitro fertilization. All new technology carries unacceptable risk... until they don't. But that's why science needs a constant feedback loop to improve understanding and safety. We can't make safe what we don't understand.
  - marvin 14y ago
    He was making a joke about the risk of goat-sized spiders.
    - Djehngo 14y ago
      I don't think drawing attention to the fact the comment wasn't short sighted, merely inane will gather much more sympathy for the poster.
      - adlpz 14y ago
        It might be interesting to introduce you people to the concept of humor.
        nrser 14y ago
        the joke here is that there are no jokes. that's what makes it funny.
nasir 14y ago
Having the silk liquid along with the milk is not enough to produce the solid silk. Spiders physical action in turning that liquid to solid is indeed another important part of that. Probably they should produce 8 legged spider goats!

habosa 14y ago

http://what-if.xkcd.com/18/ http://what-if.xkcd.com/18/ So can AK-47s.

ateev 14y ago
hahaa good one
pyre 14y ago
| air rifle fires [...] at a muzzle velocity of | 100 meters per second | The GE Genesis Series I locomotive [...] travels at | around 45 meters per second | If you bounce a single BB off the front of the | locomotive [...] you slow it down by about a foot | per day Why is everything in meters per second, then we jump to using feet all of the sudden? Isn't this just asking for conversion errors? :P
- Deestan 14y ago
  > Why is everything in meters per second, then we jump to using feet all of the sudden? Metric is easier to do calculations in, while imperial is used for the "layman terms". The intended audience is mainly american, and feet are more familiar to them than meters.
  - lucian1900 14y ago
    But that's precisely the sort of practice that causes conversion errors. Non-metric units should only ever be used in addition to the metric ones, in parentheses, if at all.
    - Avshalom 14y ago
      If you're trying to stop a train with a BB gun conversion errors are not going to be your primary worry.
- dbaupp 14y ago
  It's more poetic than "30 cm per day" or "a third of a metre per day".

minopret 14y ago

What about the materials and structure of a train car - can they sustain instantaneous force required to stop a speeding train? RRRIP! Oops, maybe not.

NamTaf 14y ago
They mention 300kN in the article, and in the design of trains that isn't a lot at all. For example, the AAR [1] standards require a railway vehicle to take up to 1.8x 1560kN longitudinal force - that is, the force imparted down the length of the train through the couplers in to the body structure - without causing bulk yield [2] of the body material. A second design requirement is for the body structure to take 4450kN 'collision' force without exceeding the ultimate strength of the body structure material. Other design criteria include, for example, crash protection of the driver's cabin if it's a locomotive where the drivers sit at the very front, so that part's often very strong and rigid as it needs to preserve a 'survivability space' for the drivers. For passenger cars, the body structure tends to have a lot of strength against longitudinal loads in order to combat the phenomenon of climbing. That is, in a railway collision with passenger cars, as the vehicles ride in to one another, there is the tendency for one to pop up/down and try to 'ride up/down' on top of/under the one in front. [3] This was demonstrated rather tragically in a particular accident (I can't find its name, sorry) where old wooden passenger vehicles did this. Their comparatively strong underframe simply sliced through the comparatively weak cabins like horizontal blades and caused huge fatalities. This is because old passenger cars used to basically be flat-top wooden vehicles with a cabin placed on top, so the body structure was very strong compared to the weak cabin. Since then, passenger vehicles must be specifically designed not to climb up on one another and do that. So really, in the sense of railway design, 300kN is minimal, especially when placed longitudinally down the length of the vehicle structure. They are far weaker against lateral collision so I guess if you ever want to cause a huge railway accident, hit a train side-on rather than end-on. [1]: Not the standards themselves, as they're not publically available - https://www.aar.org/Pages/Home.aspx https://www.aar.org/Pages/Home.aspx [2]: By 'bulk yield' I mean yielding over a significant portion of the structure. This is a legacy of the AAR standards originally being targeted towards hand calculations, where you couldn't easily inspect every particular section of every particular beam but rather you calculated it as a whole. With the advent of finite element analysis you can now do that, so it's permissible to see slight yield-levels of stress in certain small parts so long as the overall section as a whole remains under it. [3]: This will give a brief example of anti-climbers on rail vehicles: http://www.oleo.co.uk/products/rail/anti-climbers http://www.oleo.co.uk/products/rail/anti-climbers

ateev 14y ago

call the spiderman :)

p1mrx 14y ago

Anything can halt a train, if you put a lot of it in one place.

pyre 14y ago

| We were surprised to find out that the webbing | was portrayed accurately. They are forgetting that in the movie the strands of web were not all connected together. They had Spiderman at their center, holding on to them. It would seem that his body and/or his grip on the web strands would be the weakest link in trying to resist the force of a train.

maxerickson 14y ago
There's also some issues with conservation of mass. Poor Peter would at least be thirsty after all that web shooting, if not wildly hungry.

RyanKushner 14y ago

This is related to biomimicry (using nature as the inspiration for design). If you're interested in learning more, I helped start a local group: http://bayareabiomimicry.org/ http://bayareabiomimicry.org/ - Ryan

phreeza 14y ago

The article is a bit misleading in that it states that a spiders web could stop the train. The paper is clearer in this respect. Of course it should say the fictional web in Spiderman could stop the train, if it were made of the material of the actual spiders web. They assume a thread diameter of 5mm, as opposed to probably about .1mm in a real spiders web.

sageikosa 14y ago
My take on Spider-Man stopping the train was that the first several anchor points failed as anchor points in the web/anchor/train system (they underwent systemic collapse due to loads past their design tolerances). Therefore, Spidey increased the number of anchor points to more even distribute the load.