# The Naked Scientists Forum

### Author Topic: What is "Gravitoinertial Force"?  (Read 2314 times)

#### Alinta

• Jr. Member
• Posts: 14
##### What is "Gravitoinertial Force"?
« on: 05/03/2013 06:23:46 »
Can anyone explain to me what "Gravitoinertial Force" is? I am about to read a paper who's title is "Gravitoinertial Force Magnitude and Direction Influence" (for head-centric auditory localization) and I'd like to be clear at the outset what it is that I am looking at :( the internet isn't giving me much help in terms of a simplified definition of gravito-inertia nor any force that may come from it.

Thanks for helping out a beginner!

Cheers
Alinta

Mod edit: Please phrase post titles as questions.
« Last Edit: 05/03/2013 15:31:48 by JP »

#### evan_au

• Neilep Level Member
• Posts: 3949
• Thanked: 228 times
##### Re: "Gravitoinertial Force"
« Reply #1 on: 05/03/2013 11:03:46 »
The paper sounds like it is about human hearing, and how people work out which direction sounds are coming from.

As well as its familiar role in hearing, the inner ear has additional role in maintaining balance. It is capable of determining which way is "up" and "down"=gravity; when you turn your head to localise a sound, the inertia of fluid in the semicircular canals tells you how far your head has turned, so you can compare which direction the sound is now coming from.

I assume that this is where they coined the term "Gravitoinertial" - nothing as complex as the Higgs Boson!

« Last Edit: 05/03/2013 11:59:25 by evan_au »

#### lean bean

• Guest
##### Re: What is "Gravitoinertial Force"?
« Reply #2 on: 05/03/2013 18:43:10 »
Can anyone explain to me what "Gravitoinertial Force" is?

It seems to be the sum of gravitational and inertial forces acting on someone.
Quote
Sensory systems often provide ambiguous information. For example, otolith organs measure gravito-inertial force (GIF), the sum of gravitational force and inertial force due to linear acceleration.
From
http://jn.physiology.org/content/89/1/390.abstract

And, just in case… inertial force
Quote
A famous example for an inertial force is the centrifugalc force, an observer riding a merry-go-round needs to introduce that force to explain why he and all other riders are pulled away from the axis of rotation.
From http://www.einstein-online.info/dictionary/inertial-forces

#### Pmb

• Neilep Level Member
• Posts: 1838
• Physicist
##### Re: What is "Gravitoinertial Force"?
« Reply #3 on: 05/03/2013 22:24:05 »
Can anyone explain to me what "Gravitoinertial Force" is? I am about to read a paper who's title is "Gravitoinertial Force Magnitude and Direction Influence" (for head-centric auditory localization) and I'd like to be clear at the outset what it is that I am looking at :( the internet isn't giving me much help in terms of a simplified definition of gravito-inertia nor any force that may come from it.

Thanks for helping out a beginner!

Cheers
Alinta

Mod edit: Please phrase post titles as questions.
Einstein deduced that gravity and inertia are the same thing. This means that inertial forces, such as centrifual forces and Coriolis forces, forces that arise from choosing to view things from an accelerating frame of reference, are of the same nature as gravitational forces. Now they both fall under what is referred to as "inertial forces."

http://home.comcast.net/~peter.m.brown/gr/inertial_force.htm

For the mathematically inclined see
http://home.comcast.net/~peter.m.brown/gr/grav_force.htm

#### Alinta

• Jr. Member
• Posts: 14
##### Re: What is "Gravitoinertial Force"?
« Reply #4 on: 06/03/2013 01:55:42 »
Thanks for these replies guys! Sorry for being painstaking about definitions!

I've never thought of inertia as a force before - more of a tendency or a resistance. But seeing it's ties to gravity, it becomes more clear (though I have just been reading about whether gravity itself is a 'force' or not *doing my head in*).

Is this inertial force related to what I've seen read as the 'moment of inertia' - a sort of inertia in spin?

Cheers
Alinta

#### Pmb

• Neilep Level Member
• Posts: 1838
• Physicist
##### Re: What is "Gravitoinertial Force"?
« Reply #5 on: 09/03/2013 04:05:49 »
Quote from: Alinta
Thanks for these replies guys! Sorry for being painstaking about definitions!
No need to be sorry for that. In fact I highly admire that kind of attitude. Bravo! :)

#### The Naked Scientists Forum

##### Re: What is "Gravitoinertial Force"?
« Reply #5 on: 09/03/2013 04:05:49 »