00:49 13-05-2012

Pete

Thank you Gabriel!
Oh, I'm sad to hear about Nereus... =(

00:01 13-05-2012

SN

Yes, the Nereus site is gone through no fault of Evan/Empyrion, but reliable sources (those would be Evan) inform me that he is thinking about a solution...

I'll get back to the subject of revolving rings later...

22:01 11-05-2012

Anthony

Good news and Bad news: http://projectnereus.blogspot.com/2012/05/cataclysm.html

21:32 11-05-2012

Anthony

Nereus is gone? (i clicked the link, and was told the website no longer exists)

21:18 11-05-2012

Gabriel

I think there are two possible ways to create propulsion with a ring-shaped creature that turns inside-out. One way, is to have fins all-around. preferably along the inner and outer rims of the "doughnut" structure. The fins may be connected with a skin-membrane, like the webbed feet of a duck. As the long flesh rolls inside-out, the fins are extended when they are pushed backwards in water, creating propulsion. When they pass through the inside and move forward, they are folded and offer little resistance to water. This asymmetry between the front-moving fins and the back-moving ones is what creates the net propulsion.

The second way uses the body without the fins. However, the doughnut does not have a round cross-section, but the cross-cut is rather flattened. It would be rather complicated to create a "net" propulsion, i.e. the difference between the forward-propelling rim and the backward-propelling rim would be small, and that means wasted energy.

I thought of one way to solve this problem, if you think of a Möbius strip. However, the strip I think about has two opposite quadrants facing the water at 90 degrees, like a knife laid on its side on the table (therefore "paddling", and the two remaining quadrants are at a zero angle with the water, like a knife in position to cut through butter. (Therefore "cutting" forward through the water)
The idea is that the ring bends in a way that the two paddling quadrants push the two cutting quadrants forward. At the end of each stroke, the paddling and the cutting sides switch roles and then start a new cycle.
It is still a problem, because the tissue connecting the paddling and the cutting quadrants are neither at zero nor at 90 degrees angle. This creates side-forces which tend to stretch the structure and a strong muscular system needs to hold it especially if moving fast. The use of fins seems more efficient.

23:01 03-05-2012

Pete

Hallo! I am intrigued by the concept of an animal turning "inside out" to move based on the Festo's floater.
I was thinking if this is the only "design" that works this way, or if it would work with either more or less "segments" in the game. Is the machine the "middle way" of having just enough "segments" to work right and allow for a smooth movement while not having a needless ammount of failure points (joints)?
Also, I was also wondering if the present shape of the "segments" is the only one that works a "vertical" joint on one end and "vertical" joint on the other end of an individual segment... I was also thinking if a ring with triangular fins starting in the middle of the ring and probably even filling the entire inside of the ring couldn't do just the same, pushing the animal forwards by turning around.

Also, If I stay closer to the original shape, is the "four assembled triangular faces" a nexessary shape, or would a "twisted rectangle" (Like if you take a long ruler and twist it so the surfaces are horizontal on one end but vertical on the other).

On a totally unrelated note, could a mechanical floater move like this "origami kaleidoscope:" http://www.youtube.com/watch?v=fOOPRtVqej4&feature=BFa&list=HL1336077856 - by pushing on the fluid by its many surfaces? Such a "multi-facetted" shape might not be a plausible one for an animal, but it still makes me wonder...

Those are my thoughts and ideas, I don't deman an answer, but It would be cool to see your opinions on this.

14:03 30-04-2012

SN

The Festo solution seems to be exactly what Thomastapir had in mind. I wonder whether it would work with a torus, as I mentioned earlier. The points at the inside of the torus would lie on the outside after half a rotation (I cannot place images here, or I would post one to explain it with more ease). Adding flaps on the surface would provide it with an easy way to obtain propulsive force. All its tissues would have to be very elastic, though, so it would probably work better for a gelatinous jellfish-like organism than for a bone-and-muscle organism. The question is why it would evolve this particular mode of locomotion instead of a more conventional one, probably easier to achieve.

Spugpow: I do not think that a reversible creature like that corresponds well to a jellyfish with a hollow in the middle: it would look like a ring, but would not go rotate around the circular toridal axis. Or was that what you meant?

11:07 30-04-2012

Spugpow

It occurred to me while watching this video http://www.youtube.com/watch?v=mHyTOcfF99o&feature=related that a reversible creature might be able to create toroidal vortices to carry it forward through the fluid medium. I don't know enough about fluid dynamics to say whether that would work or not.

10:52 30-04-2012

Spugpow

I don't think it's too hard to justify a biological version in the water. A its most basic, it's really just a jellyfish with a centrally placed hole in the bell (it might even have greater propulsive efficiency than a jellyfish due to its flow-thru design).

06:40 30-04-2012

Spugpow

Thomastapir actually designed a creature along those lines before the Festo robot even came out: http://thomastapir.deviantart.com/gallery/?q=moebius#/d1mt1tq

19:49 29-04-2012

Evan Black

It's actually reminiscent of thomastapir's moebius fish. I question the plausibility too, but find it such a fascinating concept that I'd love to find a way to justify it scientifically.

19:01 29-04-2012

SN

Spugpow and Evan, thank you for the feedback on the importance of being whimsy. I will keep it in (probably can't stop myself anyway).

It is funny that you both found the Festo thingy at the same time. As soon as I saw it I thought that someone might turn it into a swimming organism. A donut-shaped organism could use a similar type of rotation. It would work, but would be too implausible for my tastes. But as a technical achievement it is brilliant.

03:12 29-04-2012

Spugpow

Here's a better video of the Festo device: http://www.youtube.com/watch?v=BDiTicX8HRU&feature=relmfu

19:31 28-04-2012

Evan Black

Also, a must see:

http://www.popsci.com/technology/article/2012-04/video-flying-shape-thing-propels-itself-flipping-inside-out

19:25 28-04-2012

Evan Black

I've always seen whimsy as one of the things that gives meaning and joy to life, and fictions that incorporate even a subtle form of whimsy emulate reality in that sense. I think your mixture of the two has been well balanced (so far as we've seen it), and if you were to remove it in favor of a more serious tone then some of the amusement I find in the project might be gone.

From a marketing standpoint, I think whimsy is a very important element. Even a wry sense of humor can turn a stale, colorless treatise on some scientific subject into something that people other than scientists will want to read.

Last night I had an opportunity to attend a presentation given by Philip Plait (of Bad Astronomy fame). Imagine if he had gone on for an hour spouting raw facts about asteroids and comets, then walked step by step through the math to illustrate implications of possible impacts with Earth. The demographic of the audience was such that, had he done so, perhaps a dozen would have listened with rapt attention, another few would stay out of politeness, but the hundreds more in the auditorium would have walked out due to boredom. Instead, Dr. Plait was his usual whimsical self, and the whole room was on the edge of their seats as he described to them REAL science.

In the case of Furaha, pursue plausibility as much as you can, but if you find that the whimsy of the project is hurting as a result, find a way to preserve it. There are those of us in the world who would read a book about Furaha even if it had the same sense of humor as Grey's Anatomy (the book, not the show), but more people are likely to be interested in the book if it has its light and amusing parts as well. For some reason, publishers like that.

Berichten: 106 t/m 120 van de 930.
Aantal pagina's: 62
Nieuwer5 6 7 [8] 9 10 11Ouder

Free guestbook of MyGB.nl