Alt-BEAM Archive
Message #08495
To: beam@sgiblab.sgi.com
From: "Timothy Flytcher" flytch@hotmail.com
Date: Mon, 20 Dec 1999 13:04:44 PST
Subject: [alt-beam] Re: Lets Hypothesise...
>
>i certainly hope you are wrong about this.
>
>otherwise there will be a whole lot of bats that won't find any food
>tonight. and i don't want to step on dead, starved bat bodies tomorrow.
>
Hold on now... Bats use a different system... It's echo location... there
ears tell them which direction ... their brains tell them how far... They
screech then listen... screech then listen... the time it take for the sound
to go out then bounce bake tells them the distance... active system... not
passive...
Timothy...
>
> >I don't think having two ears helps me estimate distance to a noise
> >source. I estimate distance based on the volume of the noise and my
> >expectation of how loud that noise should be at a given distance. I
>can
> >do this fairly well even with one ear covered (or congested with an ear
> >infection).
> >
> >Having two ears does help, however, in figuring out the DIRECTION of a
> >noise source.
> >
> >
> >At 11:37 PM 12/19/99 -0500, you wrote:
> >>In a message dated 12/19/99 11:30:26 PM Eastern Standard Time,
> >>richard@cqc.com writes:
> >>
> >><< When you hear a noise, you can't make
> >> an accurate assessment of it's distance from you. You're lucky if you
>can
> >> even tell the direction it's really coming from. We make no distance
> >> measurements when we hear things. I don't really think that we make
>any
> >> visual measurements unless we're specifically trying to do so.
> >>
> >> The way we navigate through our world is what I call the "Second star
>to
>the
> >> right, and straight on 'till morning" system. We pay little attention
>to
> >> distances and such things. We see something interesting, we go that
>way
> >> until we see it better. There's no real measurement involved. That's
>why
> >> we need maps and such things.
> >> >>
> >>
> >>If any of this was true, then we would all have one eye and one ear.
>The
> >>truth is that distance is quite an important factor in navigating our
>world.
> >>We have two eyes and two ears so we can triangulate distances.
> >>
> >>
> >>Gary
______________________________________________________
8496 Mon, 20 Dec 1999 13:19:27 PST [alt-beam] Re: Frist, let's keep it simple. Lets Hypothesise... beam@sgiblab.sgi.com "Timothy Flytcher" I think it is like the man that asked Leanardo how to carve a statue out of
stone... His reply was "start with a big pice of marble and remove
everything that is not the statue" ... Some times it is good to think
complicated then pair it down till you find the bot underneath... I tend to
think that way... sorry if it confusing to some :) it isn't meant to be...
Timothy...
>In my opinion, things should be kept simple. I know there is the urge to
>build really cool electronic circuits, but if you want robots to
>communicate the location of a really bright source of light, you don't
>need anything fancy. Think about it, were all talking about sound, using
>chirps or IR transmitters. And then talking about triangulation and dead
>reckoning and stuff. It's nice, but in my opinion, we don't need it for
>waht we are trying to do. THink about it. Nature tends to keep things very
>simple. Often many of the most complex mechanisms came about by accident,
>and were more of 'adverse effects' of something else. I have a super easy
>and effective solution for communication between our little photovores.
>
>Paint them white.
>
>See? And if you think about it, it would work marvelously. The brighter
>the light pool the robot sit's in, the more reflected and disperesed light
>will be reflected out in all directions. Any ordinary photovore would be
>easilly attracted to something like a white colored bot. Flocking would
>natural. Then think about the possible predator/prey results. The predator
>bots would chase down the prey bot's because they would know what to look
>for (a bright bot) but then takeing ita step further, if it were in nature
>the prey bots would be colored BLACK so as not to attract predators, but
>the predators would be colored WHITE so the prey is attracted to the
>Predators. Interresting? I know it defeats the purpose of fancy
>electronics. But It works, Mark T's Unicores could tell the difference
>between white and black squares, so bot's would be no problem. Anyway,
>that's enough of my theorizing self.
>
>dennison
>
>
>On Mon, 20 Dec 1999, Timothy Flytcher wrote:
>
> > >I don't think having two ears helps me estimate distance to a noise
> > >source. I estimate distance based on the volume of the noise and my
> > >expectation of how loud that noise should be at a given distance. I
>can
> > >do this fairly well even with one ear covered (or congested with an ear
> > >infection).
> > >
> > >Having two ears does help, however, in figuring out the DIRECTION of a
> > >noise source.
> > >
> >
> > but yes it dose... if you know the db's (sound level) of the source...
>like
> > finding your pager or phone... two ears gives you direction... the rest
>is
> > reasoned... this can be duplicated in a bot... especially if they are
> > talking/listening to one another(fixed sound level)...
> >
> > ______________________________________________________
> > Get Your Private, Free Email at http://www.hotmail.com
> >
> >
>
______________________________________________________
8497 Mon, 20 Dec 1999 13:22:05 PST [alt-beam] Re: Lets Hypothesise... beam@sgiblab.sgi.com "Timothy Flytcher" >Echolocation is specific to bats (non-aquatic beasties). Exception, not
>the
>rule.
>
>8^P 2U2!
>
What about dolphins????
______________________________________________________
8498 Mon, 20 Dec 1999 13:27:23 -0700 [alt-beam] Re: Lets Hypothesise... beam@sgiblab.sgi.com Senior I'm not educated in this subject, but I have to say, I fully disagree
with you! :)
We need to know where the cup is, right? Well, we live in a 3D world! To
know where something is, we need THREE coordinates! From the image your
eyes see, we get two co-ords, and the third is the distance away from
you!
Now, let me give you an example: If you had no idea how far the cup is
away from you, you'd have to reach out very slowly, otherwise, you would
knock the glass over! Maybe I'm odd, but I can reach out and grab that
glass real quickly if I need, without knocking it over. Your mind NEEDS
to know the distance to be able to do this. NOTE: Notice, also, that I
didn't first think "Okay it's three feet away" and then think "I'll move
my hand three feet out."
Another example: If we are not constantly measuring distance in whatever
units our mind uses, then how does my mind subconciously know I can walk
down a never before seen hallway without bumping into the wall at the
end?!! If I didn't know the end was much farther than where I am, I
would think I couldn't go any further!
Kyle
Richard Caudle wrote:
>
> > Ok, here's a little experiment to try:
> >
> > Place an object on your desk.
> > Look at it.
> > Look away.
> > While looking away, reach out and grab it.
>
> Is that really calculating distances or just remembering where the cup is?
> I can give you very specific information as to where several things are in
> my house, car, and office. I can't tell you how far away my oscilloscope
> that sits on my desk at work is, but I can tell you what it looks like where
> it's sitting. Look away and grab it just tells me that your memory, like
> mine, is photographic. Are we just trying to embue ourselves with
> computerlike qualities? Thinking and doing are totally different things.
>
> I'm not saying that I'm not wrong, just not convinced.
>
> Oh yeah, I love a good arguement! No, you don't! Yes, I do!
>
> Richard, the Bullheaded
8499 Mon, 20 Dec 1999 17:10:13 -0500 [alt-beam] Re: Lets Hypothesise... "Richard Caudle" I wasn't talking about aquatic beasties, only non-aquatic!
Richard the Misunderstood
8500 Mon, 20 Dec 1999 15:15:27 -0800 (PST) [alt-beam] Re: Lets Hypothesise... beam@sgiblab.sgi.com Iv Clarence Harper
On Mon, 20 Dec 1999, Senior wrote:
> I'm not educated in this subject, but I have to say, I fully disagree
> with you! :)
> We need to know where the cup is, right? Well, we live in a 3D world! To
> know where something is, we need THREE coordinates! From the image your
> eyes see, we get two co-ords, and the third is the distance away from
> you!
>
the 3rd point isn't actually the distance, but rather, the feedback your
brain recieves from the muscles which control the position your eyes and
lens. the brain is set
to understand that, if left eye is at x degrees from center and right eye
is x degrees from center, and the resulting image is in focus, then the
object is y distance away. Of course, y isn't expressed as a literal
foot/ meter/ AU measurement, but rather, as a relative positioning away
from the body.
On this note, I have been experimenting with the range finding units from
video cameras. The camera has an IR emiter that is set at a particular
angle, and then a reciever which has a variable angle. The variable lens
is atached to the camera's lens housing and controls the auto focus motor.
when the rangefindeer cannot make out it's own signal, it refocuses the
camera till its own lens is positioned properly.
-Clarence
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