Comments on: Why can't Godfrey work the trackpad?

Question: Why can't Godfrey work the trackpad?

Dr. Wu — Thu, 15 May 2008 20:50:06 -0800

Why, when I drag the fleshy (i.e., not furry) part of my cat's paw across the trackpad on my MacBook, does the cursor not respond?

No, seriously.
What is it about the difference between his paw and my finger that makes the cursor move?

No cats have been harmed in the formulation of this question.

By: Mr. President Dr. Steve Elvis America

Mr. President Dr. Steve Elvis America — Thu, 15 May 2008 21:04:41 -0800

They work by sensing the human operator's soul.

Seriously, though, it's explained on Wikipedia. I don't really get it, though.

By: Dipsomaniac

Dipsomaniac — Thu, 15 May 2008 21:04:56 -0800

Try dragging something larger than the tip of your finger across the trackpad. When I do that to my MBP, it doesn't respond. The pad depends on a small locus of input.

(I liked the first answer better, though).

By: jamaro

jamaro — Thu, 15 May 2008 21:06:07 -0800

His paw pad isn't moist enough. I have the same problem w/ my trackpad, however, I'm not a cat.

By: Class Goat

Class Goat — Thu, 15 May 2008 21:06:27 -0800

Touchpads take advantage of the fact that the human is a capacitor. Since a cat weighs far less than a human, it will have a much smaller capacitance and will fall below the activation threshold for the circuit.

By: danb

danb — Thu, 15 May 2008 21:07:17 -0800

jamaro: In that case, how come I can use the trackpad with my knuckle or my elbow?

By: loiseau

loiseau — Thu, 15 May 2008 21:15:10 -0800

My cat's paw moves the trackpad on my iBook. Maybe it's just more sensitive than yours.

By: loiseau

loiseau — Thu, 15 May 2008 21:15:28 -0800

(The trackpad, not the cat.)

By: jamaro

jamaro — Thu, 15 May 2008 21:17:07 -0800

danb: it would be impolite for me to speculate why you have oily knuckles. Excessively dry hands + trackpads are a PITA, though I can't maintain they are the only reason why a trackpad would not work.

For small values of interest, I have the same problem with fingerprint scanners. I have to lotion up before they register my touch.

By: katemonster

katemonster — Thu, 15 May 2008 21:30:27 -0800

My cat's paws work too, much to my frustration. For point of reference, the computers i question are a Fujitsu Lifebook and a Toshiba Satellite; she can control both.
However, unlike loiseau, I am fully prepared to speculate that my cat is more sensitive than yours.

By: turgid dahlia

turgid dahlia — Thu, 15 May 2008 21:47:48 -0800

Not enough pressure/density/texture/moisture? This sounds like something for The Straight Dope!

By: bmalicoat

bmalicoat — Thu, 15 May 2008 22:57:19 -0800

I'll add that my cat's paw easily operates my iPhone, no doubt due to its multitouch abilities. Since most trackpads don't have that I'm siding with Dipsomaniac, needs smaller contact point.

To add to the moisture issue, I had a ton of trouble using my trackpad in Florida during some humid summer days. No contact necessary, just hover anywhere near the pad and the cursor slides all over.

By: stefanie

stefanie — Thu, 15 May 2008 23:06:52 -0800

I just tried this with my (exceedingly patient) cat, and it seems to work with a single locus of input, regardless of size. We were able to use the trackpad using single "fingers" or with the pad, but we were not able to get any trackpad movement if there was more than one bit of input (two "fingers", or finger + pad/palm area).

I will now use his paw to navigate to and click the "Post Comment" button...

By: moonmilk

moonmilk — Thu, 15 May 2008 23:21:37 -0800

Because this is for SCIENCE, I tested my dog's paw on this Thinkpad's trackpad and it worked just fine.

By: Dipsomaniac

Dipsomaniac — Thu, 15 May 2008 23:26:02 -0800

In the interests of Science, I grabbed one of our cats and tried it on the MBP. Her paw doesn't move the cursor but she can scroll pages with it, likely because multi-touch can register larger/multiple inputs.

Then she ran away. Damn Luddite.

By: markovich

markovich — Thu, 15 May 2008 23:28:11 -0800

I can confirm that the hoof of a horse does not work on the trackpad. I'm not sure why though.

By: peacheater

peacheater — Thu, 15 May 2008 23:52:44 -0800

Try wearing a pair of gloves and trying to move the mouse on your keypad. That won't work either. I guess it needs a small locus of pressure to work.

By: peacheater

peacheater — Thu, 15 May 2008 23:53:08 -0800

By gloves I meant woolen mittens.

By: tim_in_oz

tim_in_oz — Fri, 16 May 2008 01:15:46 -0800

Wolfhound paws won't activate the trackpad on my iBook either. They will, however, mash leaf litter and dirt into the keyboard. The things I do in the name of science...

By: MadMage

MadMage — Fri, 16 May 2008 02:44:14 -0800

My cat's paw works the touchpad on my Toshiba Satellite without a problem.

I recommend the experimental protocol specify a sleeping test subject and handy can of tuna.

By: googly

googly — Fri, 16 May 2008 04:33:14 -0800

Additional data point:

Computer: Dell Latitude X1 laptop.
Input device: trackpad.
Organism: cat, black, short-hair.
Limb: paw.
Result: Success.
Conclusion: this explains all the cat-scanner sites in my browsing history.

By: catlet

catlet — Fri, 16 May 2008 06:15:04 -0800

Cat resident #1, 15-pound British Shorthair tabby: cannot operate trackpads. Dislikes all computers except warm laptops that have just been closed.

Cat resident #2, 11-pound Abyssinian: can operate trackpads and mouse buttons, and is really good at turning on the horrific zoom "feature" of my wireless keyboard. Also involved in intimate nuzzle-relationships with the monitor and likes to join conference calls.

Computer tested: HP work laptop with trackpad, and the Logitech wireless input devices on an HP Pavilion desktop. If I could find the power cord to my accursed iBook, I would test Cat #2 on that, but I suspect he ate the power cord.

By: Dr. Wu

Dr. Wu — Fri, 16 May 2008 06:36:39 -0800

Hi, all, and thanks for the answers! (Sorry for the delay - I posted just before going to sleep, and have only now had a moment to return to this thread.)

Godfrey is right here, tucked between my arm and the laptop, and he agreed to another trackpad-testing session, based on your answers above.

1. We adjusted his capacitance (using a Flux Capacitor, of course), and this had no effect.
2. I cleaned all oil, moisture, and Gritty Kitty™ brand kitty litter from his paws, and this had no effect.
3. BUT! When we used one of his "fingers," the cursor DID move! It wasn't a perfectly smooth movement, and it was sort of intermittent, but it did work. I think it was the "too many inputs" problem, simply enough. So it was a simple solution to a silly question, but I'm glad I posted it, as this turned into a fun thread.

Thanks!

By: desjardins

desjardins — Fri, 16 May 2008 15:18:30 -0800

I can't wait to go home and try it with my two non-declawed cats.

I'll be sure and post an update from the ER.

By: ericb

ericb — Fri, 16 May 2008 15:53:22 -0800

Why can't Godfrey work the trackpad?

Easey-peasey. He's not a dog!

By: Luddite

Luddite — Fri, 16 May 2008 16:54:59 -0800

Then she ran away. Damn Luddite.

I swear, I haven't been anywhere near your cat.

By: Susurration

Susurration — Fri, 16 May 2008 17:14:27 -0800

My dog's furry chin works on the trackpad - she scrolls back and forwards in my browser quite deliberately, when she thinks that I am spending too much time on the PC. It may be because that part of her is slobbery. I suspect that the capacitance required depends on moisture to make a contact. Try again after she has been licking her paws.

By: DU

DU — Fri, 16 May 2008 18:03:36 -0800

Relatedly: Why don't my kids come running when I run the can opener?

By: Horace Rumpole

Horace Rumpole — Fri, 16 May 2008 19:43:26 -0800

Thanks to Horace's curiosity about whether I could use the trackpad or not, I have now become fully conversant in the operation of his computer. I'd chat more, but I have to go "borrow" his credit card and visit www.wildpacificsalmon.com.
--Perseus (Discourse Marker and Horace Rumpole's cat)

By: Merik

Merik — Sun, 18 May 2008 21:38:25 -0800

1. We adjusted his capacitance (using a Flux Capacitor, of course), and this had no effect.

I believe its called a Fluff Capacitor.

By: togdon

togdon — Sun, 18 May 2008 21:41:33 -0800

I just tried with my polydactyl cat, and she is fully capable of multi-touch gestures, which given her nature was to be expected. The non-polydactyl cat looked at me like I was fucking crazy and ran away.

I'm pretty sure that Horace Rumpole's answer was better, but I figured we needed a polydactyl cat data point for completeness sake.

By: Fuzzy Skinner

Fuzzy Skinner — Sun, 18 May 2008 21:54:29 -0800

It relies on the electrical reaction with human skin. Try using your fingernail, flat on the trackpad. It won't work either. Kitty pads are mostly dead tissue.

(I'm splainin' this from memory of stuff I read one time in the bathroom, and reserve the right to disown this answer by saying my cat posted it from my MacBook. She uses a USB mouse.)

By: nat

nat — Sun, 18 May 2008 23:10:40 -0800

Items which cannot work my Dell Inspiron trackpad, despite having small cross section:

the end of my watch
the base of my webcam
my fingernail
a nearby allen wrench

Areas of future research:
Can a hamster turn on a touch-fan?
(Actually this is past research; my sister and I were trying to figure out how the fan worked. You touched on its grate to turn on or off. The hamster, held in insulating gloves, could not turn on the fan. I should scan in that picture...)

By: you're a kitty!

you're a kitty! — Mon, 19 May 2008 21:58:04 -0800

I can get the top of my fingernail to control the trackpad (iBook G4). Good to know if I develop onychogryposis.

By: Vindaloo

Vindaloo — Mon, 26 May 2008 10:59:00 -0800

I just tried with my polydactyl cat, and she is fully capable of multi-touch gestures, which given her nature was to be expected. The non-polydactyl cat looked at me like I was fucking crazy and ran away.

Do you hear that Mefites? That is the sound of ultimate suffering. My heart made that sound when the six-fingered cat killed my father.

By: disillusioned

disillusioned — Mon, 07 Jul 2008 00:29:09 -0800

Clearly, we need to compile a gallery of people manipulating their animals to see if they work their computer's trackpads. We'll call it... pawpads.com or something that's available...