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Insects, by weight, are many times
stronger than humans, or mammals, or
anything! A whole bunch of insects
pushing or pulling in unison would create
a pretty efficient and powerful engine!
They can create the electricity for your
house while eating your trash! But how do
you get roaches
to all work together?
You stick electrodes in their brain! Like
scientists are already doing. If you could
efficiently and simply find where to place
the electrode in their brain, you can
control them. Epoxy them to the outside
of a drum and put that drum inside
another drum with a slightly larger
diameter. Press the "go" button and watch
them make you some of that electrical
goodness! Let them eat every day, or
they'll die.. But a well-kept cockroach
should keep for maybe a year! Worker
roaches that generate electricity and are a
solution to trash!
When one worker isn't pulling his/her
load, he is rejected and eaten by his fellow
laborers.
UC Berkeley: Cockroach Leg Force
http://jeb.biologis...bstract/198/12/2441
R. J. Full, Yamauchi, and D.L. Jindrich [jutta, May 09 2007]
On Growth and Form
http://www.amazon.c...d=1178753003&sr=8-2
completely discredits "for their size" arguments [bleh, May 09 2007]
Running Bugs
http://ufbir.ifas.ufl.edu/chap39.htm
American Cockroaches are faster when they only use two legs! [elhigh, May 15 2007]
Scientists use Robotic Bugs to Conrol Cockroaches
http://www.physorg.com/news114361311.html
Robo-religious roach leaders. [quantum_flux, Nov 18 2007]
[link]
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Your apparatus needs a bit more design to it. How are you going to accommodate the eating, for example? How do you efficiently swap in replacement roaches to replace the eaten ones? |
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The roaches can eat each other, when necessary. You just need to periodically add more. Anyway, gross. [-] |
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//Epoxy them to the outside of a drum and put that drum inside another drum with a slightly larger diameter// |
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Then put those inside another drum of a slightly larger diameter, etc. and pretty soon the force multipler will exceed the power output of the most powerful engines made. Imagine an supertanker powered by a 490 terraroach engine. |
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Since the actual power output of a single roach is so small, r.p. would have to be measured in at least mega- or gigaroaches. |
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//Insects, by weight, are many times
stronger than humans, or mammals, or
anything! // |
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I think this is a popular myth
perpetuated by the gullible, and I don't
believe it. You can make all kinds of
comparisons like "If an ant was as big
as a human it would be able to carry
Venezuela" - but that is silly. It's just
a natural consequence of the square/
cube law. A human the size of an ant
would be bizarrely strong. |
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So, my question is this. What is the
actual power output per hundred
kilograms of live roaches? And what is
the actual power output of a hundred
kilogram human being? |
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I would bet a week's cheese that the
human has by far the higher power
output, weight for weight. We have a
higher proportion of muscle (by
weight), and a vastly higher oxygen
demand (by weight). |
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In fact, here is a back-of-envelope
calculation. I am guessing that a roach
could pull with a force of maybe 1gram
, and move (whilst pulling that
load) at 1m/s - I think that's a generous
estimate (the roach can probably pull a
bigger load, but at a lower speed).
Hence, the power output of one roach is
1gram m/s or 0.001kg m/s or 0.001W.
I am also guessing that a roach weighs
maybe two grams; hence the power
output of bulk roach is about 0.5W/kg. |
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A human (estimated weight 100kg) in
good condition is (according to a variety
of websites) able to generate about
300W of power, in a bicycle-style
system, or about 3W/kg. |
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No contest. Any of my figures could be
out by a factor of 10, but it's certainly a
myth that insects are "many times"
stronger than humans (or even, heck,
mammals). |
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Not a bad estimate. The roaches in the study to the left weighed about 3g and were running at about 28cm/s. (It was hard to measure, because they scurried.) They exerted maximum force while righting themselves - around 0.14 N per leg - and they're probably doing it with reasonable speed (although they're pretty unpredictable about it), but they're not lifting themselves all that far when they do that. |
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Let's assume a cockroach turning itself upside down is pushing with three of its legs to lift itself 5mm off the ground for 0.5s; that would amount to (3 * 0.14N) * 0.005m / 0.5s, or a stupdendous 0.19 W, or 63.5W for 333 of them (1kg bulk roach) pushing simultaneously! |
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I've probably screwed up somewhere in this calculation, and I don't think roaches can *sustain* this kind of load - but hey. Welcome to the roachtrix. |
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And of course all these calculations are based on wild roaches. Selective breeding could generate a much more powerful breed of draft roaches that could pull even more weight. And with a 100 day lifecycles breeders could easily produce four or more generations per year. |
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According to Jutta's calcs, 3,933 roaches would be required to generate 1 h.p. Thus to produce the 20,000 h.p. (15M watts) necessary to power a supertanker, you would require +/- 78 million roaches. |
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Taking into account frictional losses, time spent sleeping, eating, roaches trampled to death, epoxy failure, etc., it seems reasonable that a 100 to 125 megaroach engine would be sufficient for the task. |
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I don't think roaches are the ideal insect as they are quite well armoured and winged which are both a waste of weight for our purposes, what you need is a something muscular and soft. Worms would be ideal if you could find a way of using their strength. Crickets would be better than roaches although they are also armoured and winged. |
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[Jutta] I don't think you should invest. |
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A 3g roach exerting a force of 0.14N x
3 legs (or 0.42N) against gravity for
0.5s will acheive an upward velocity of
65m/s, or about 145mph. Since self-
righting cockroaches do not routinely
attain this speed, it is probably safe to
assume that they do not apply 0.14N
per leg for the 0.5s that you assume. |
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A better estimate would come from
measuring the speed of a cockroach (of
known weight) running up a rough wall
- preferably under duress. |
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145mph? I guess that explains the holes in my ceiling... |
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There's some weird anatomical difference between the "righting" mechanism and the walking mechanism for roaches - that's why I figured that sticking with the first would be advantageous. |
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I guess my time estimate was off by a few orders of magnitude, then. For how long does a 3g roach have to exert pressure with three 0.14 N legs to jump 2cm into the air? |
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(I can see this turning into a physics test that yields lots of concerned phone calls from parents.) |
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//For how long does a 3g roach have to
exert pressure with three 0.14 N legs to
jump 2cm into the air? // |
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OK, just for you. But this is not what
the Research Division of Maxwell
Industries is meant to be doing..... |
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We first make several simplifying
assumptions. We assume that the
roach is a rigid jumping body, and that
it is the centre of mass that has to rise
2cm. We also assume that no energy is
used in generating rotation, and that air
resistance can be ignored. |
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Now, from first principles. Let the
roach leave the ground with velocity Vo
(we assume that, once it has left the
ground, no forces other than gravity
act). Let the time taken for it to reach
the peak of its trajectory be T. Let the
height to which it ascends be S, and let
acceleration due to gravity be g. |
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T=Vo/g (time of ascent is initial speed
divided by rate of deceleration due to
gravity) |
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During this time, the roach goes from
its initial velocity (Vo) to zero (at its
apogee), hence its mean velocity, Vm,
will be given by: |
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Hence, the distance S risen will be
T*Vm, ie: |
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S=[Vo/g] * [Vo/2] = Vo" /2g (I'm using
" to indicate squared) |
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Hence, given that g=10m/s/s and S in
this case = 0.02m, we get |
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In other words, the roach must leave
the ground at 0.63m/s in order to
ascend 2cm. |
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So, how long will 0.42N (0.14N on each
of three legs) have to act on a mass of 3
grams to accelerate it to 0.63m/s? |
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We will have an acceleration of:
A=F/M (force/mass), or in this case: |
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A=0.42/0.003 = 140m/s/s
but this ignores the effect of gravity
acting during the launch phase; gravity
will reduce the upward acceleration by
10m/s/s - hence in fact: |
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hence, the roach will reach the
necessary launch velocity of 0.63m/s in
time Tv given by: |
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Tv=Vo/A
= 0.63/130
= 4.8 x 10e-3 |
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In other words, the roach needs to push
for about 4.8 milliseconds (with three
legs, at 0.14N each) in order to launch
itself 2cm vertically. |
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Either get your calculations right or just switch to ants, which are widely known to be the strongest insects, capable of carrying 25 to 50 times their own weight. |
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I do like the idea of making roaches useful for *something*. |
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//which are widely known to be the
strongest insects// This is where I came
in. |
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Yeah, sigh. For what it's worth, the paper points to some beetles who are known to be very strong. |
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Thanks for the beautiful calculations! My only problem is that with those assumptions, the resulting Wattage comes out even higher - (3 * 0.14 N * 2cm) / 0.005s = 1.68 W (!?) |
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There's a book out there from the early
1900's by D'arcy Wentworth Thompson
called On Growth and Form in which he
discusses in great detail the scaling
limits of certain animals physical
properties. He shows (both
conceptually and mathematically) how
birds can only attain a certian size with
their current design, and how the
mechanisms of insects are designed
ideally for their size. All in all, it totally
discredits all those "for their
size/weight" claims. |
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//the resulting Wattage comes out even
higher// |
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True. However, the total flight-time of
the jumping roach is about 120msec
(takeoff to landing), so it is only
acheiving this power output for
5/120ths of the time - even if it is
constantly jumping to right itself. This
would give an average power of 70mW,
and I doubt if the typical roach could
keep even this up for long. |
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There's no problem with having a peak
power output in the low Watts (or even
more), as long as it's not sustained. |
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You might be able to get a constant few
milliwatts out of a roach as rotary
power, if only someone would devise a
very small piece of buttered toast and a
suitable means of attachment. |
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I chose roaches for the reasons: |
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- There's LOTS of 'em.
- The eat LOTS of things. (why do you
think they hang around the trash, they
aren't waiting for you to open the
fridge.)
- They are simple. (I haven't heard of
any other prominant/successful brain
control with electrodes than with the
cockroach)
- Using larger animals might insight
"cruelty to animals". |
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Ants lifting argentina? never heard of
it.. I HAVE heard of lifting cars though.
Muscle efficiency certainly isn't the only
factor here. |
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//But this is not what the Research Division of Maxwell Industries // I honestly read this as "Roachsearch"! |
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What you need is a big roach waterwheel. Get about a billion of them and let them carry their own weight up there and then ride the wheel down. manipulate them with the food source, which is also the fuel. |
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Yick. I'm grossing myself out. |
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oh, oh, I've thought of an insect that produces a measurable sustained force which can be used in a useful way :D |
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The mighty dung beetle. All you need is a load of crap at the bottom of a slope, the beetles push balls of it up hill where it drops into a chute with some kind of wheel with your electricity generating doohickey. The ball 'o poop is them expelled at the bottom of the slope in a poetically dantesque version of insect hell. |
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Dung beetles don't take care of the trash
problem, but if you needed to power a
dairy farm, maybe. In my experience,
roaches are by far the most indestructable
insects on the planet. |
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OK, so the roaches can't lift Venezuela. Sounds like they could only manage Rhode Island, and even then only for brief periods. |
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So what we have is cockroaches juggling Rhode Island. |
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I've always perceived the land speed of the bug to be pretty significant, not on a raw-speed basis but on a body lengths per second basis. If it's an American Cockroach, which adult measures ~1.5 in (about 3.8 cm), then you're looking at nearly 40 body lengths per second. I'd have to break 300 mph to do that. |
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It would be even more relevent to include the leg length of the critter in question when calculating body lengths per second, but I'm not going to get intimate enough with the cockroach to measure his inseam. |
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Found an interesting link talking about land speed of some bugs. |
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// so the roaches can't lift Venezuela.// |
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How about those African Beetles? On steroids!? Those thinks are huge, they're like small army tanks. When I was little, I tried to squish one under my bike tire, and to my dismay it did a freaken push-up against my bike tire, completely unharmed and unscathed, the thing just got up and went away. |
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Also, check out the above link about how scientists changed the behavior of cockroaches using a robot. I guess this might be doable, but wouldn't it be easier to train horses though!? Anyhow.... [+] |
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