# The Naked Scientists Forum

### Author Topic: What are multiple dimensions?  (Read 3735 times)

#### thedoc

• Sr. Member
• Posts: 511
• Thanked: 12 times
##### What are multiple dimensions?
« on: 21/03/2012 09:07:01 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
« Last Edit: 21/03/2012 09:07:01 by _system »

#### Soul Surfer

• Neilep Level Member
• Posts: 3345
• keep banging the rocks together
##### Re: What are multiple dimensions?
« Reply #1 on: 22/03/2012 09:00:37 »
We are so used to our three dimensions of space and one of time that it is very difficult to think of more than these so let me give you a simple example. suppose I have a particle that is moving through space at a particular speed and there are other things in this space that allow be to say where it is using standard cartesian co ordinates( up/down  left right and forwards/backwards ) it is moving with a particular velocity in a particular direction so I can think of it as having at a particular instant in time  a position in three dimensions and a velocity resolved in three dimensions.  that makes seven independent dimensions so far.  Dimensions in mathematical terms are really just the number of different things you need to describe what something is doing.

#### Ęthelwulf

• Sr. Member
• Posts: 358
##### Re: What are multiple dimensions?
« Reply #2 on: 22/03/2012 10:01:41 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
The word ''dimension'' is really another way of saying ''degrees of freedom''. If I was walking in my living room, I would have three dimensions I could walk. Forward, left or right.

We live in a world with multiple dimensions. Three obvious dimensions, length, width and height.

#### imatfaal

• Neilep Level Member
• Posts: 2787
• rouge moderator
##### Re: What are multiple dimensions?
« Reply #3 on: 22/03/2012 10:43:28 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
The word ''dimension'' is really another way of saying ''degrees of freedom''. If I was walking in my living room, I would have three dimensions I could walk. Forward, left or right.

We live in a world with multiple dimensions. Three obvious dimensions, length, width and height.
Um - no.  In your living room whilst walking you have only two degrees of freedom; forward (backward is negative forward) and right (left is negative right).  The third degree of freedom requires stairs, a ladder, or jumping; and is up (down is negative up).  Our natural world really only requires two dimensions (longitude and latitude) - although sometime you will need to specify height above ground (depth below being negative height) which would be a third dimension.  To describe a concrete object in our world would normally require 3 dimensions although many object have mathematical concepts that allow you to lower that

#### Airthumbs

• Hero Member
• Posts: 958
• Personal Text
##### Re: What are multiple dimensions?
« Reply #4 on: 22/03/2012 19:40:39 »
Call me anything you like but I thought time was a dimension?

#### Ęthelwulf

• Sr. Member
• Posts: 358
##### Re: What are multiple dimensions?
« Reply #5 on: 23/03/2012 01:20:03 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
The word ''dimension'' is really another way of saying ''degrees of freedom''. If I was walking in my living room, I would have three dimensions I could walk. Forward, left or right.

We live in a world with multiple dimensions. Three obvious dimensions, length, width and height.
Um - no.  In your living room whilst walking you have only two degrees of freedom; forward (backward is negative forward) and right (left is negative right).  The third degree of freedom requires stairs, a ladder, or jumping; and is up (down is negative up).  Our natural world really only requires two dimensions (longitude and latitude) - although sometime you will need to specify height above ground (depth below being negative height) which would be a third dimension.  To describe a concrete object in our world would normally require 3 dimensions although many object have mathematical concepts that allow you to lower that
I was in a rush when I typed that. Assured, your explanation is correct. I was just trying to demonstrate how easily we can move in three dimensions.

#### Ęthelwulf

• Sr. Member
• Posts: 358
##### Re: What are multiple dimensions?
« Reply #6 on: 23/03/2012 01:21:28 »
Call me anything you like but I thought time was a dimension?

Minkowski's relativity is. Einstein's original formulation did not have this feature.

Personally I think it is good as a calculational tool but nothing more.

#### Airthumbs

• Hero Member
• Posts: 958
• Personal Text
##### Re: What are multiple dimensions?
« Reply #7 on: 23/03/2012 02:50:26 »
Call me anything you like but I thought time was a dimension?

Minkowski's relativity is. Einstein's original formulation did not have this feature.

Personally I think it is good as a calculational tool but nothing more.

Hey thanks for that Aethelwulf, I am a little confused which is a good thing otherwise I would know everything!!  :)

#### yor_on

• Naked Science Forum GOD!
• Posts: 11993
• Thanked: 4 times
• (Ah, yes:) *a table is always good to hide under*
##### Re: What are multiple dimensions?
« Reply #8 on: 24/03/2012 13:35:46 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
The word ''dimension'' is really another way of saying ''degrees of freedom''. If I was walking in my living room, I would have three dimensions I could walk. Forward, left or right.

We live in a world with multiple dimensions. Three obvious dimensions, length, width and height.

Very true. 'Degrees of freedom' is a concept widely used in physics, but its definition is, as far as I understand, exactly as you described it. (As long as we agree on that what you meant there is length, width and height)
« Last Edit: 24/03/2012 13:37:45 by yor_on »

#### Pmb

• Neilep Level Member
• Posts: 1838
• Physicist
##### Re: What are multiple dimensions?
« Reply #9 on: 24/03/2012 14:17:39 »
Tim DiGennaro  asked the Naked Scientists:

Can you explain to me, a 6th grader, how multiple dimensions exist, if they even do?

What do you think?
The word ''dimension'' is really another way of saying ''degrees of freedom''. If I was walking in my living room, I would have three dimensions I could walk. Forward, left or right.

We live in a world with multiple dimensions. Three obvious dimensions, length, width and height.
One should be very clear on that point. A two dimentional curve can exist in a three dimentional space. So the first thing you need to distinguish is what they mean by "multiple dimention. 3D means that it takes at leae three numbers to uniquely specify a point in 3D space.

#### Pmb

• Neilep Level Member
• Posts: 1838
• Physicist
##### Re: What are multiple dimensions?
« Reply #10 on: 24/03/2012 14:19:07 »
Call me anything you like but I thought time was a dimension?

Minkowski's relativity is. Einstein's original formulation did not have this feature.

Personally I think it is good as a calculational tool but nothing more.
To be precise; time is one of the dmensions in spacetime not in space.

#### yor_on

• Naked Science Forum GOD!
• Posts: 11993
• Thanked: 4 times
• (Ah, yes:) *a table is always good to hide under*
##### Re: What are multiple dimensions?
« Reply #11 on: 25/03/2012 17:27:45 »
True Pete. SpaceTime is not as four dimensions put together, it's one whole description of where we live.

#### Bill S

• Neilep Level Member
• Posts: 1826
• Thanked: 12 times
##### Re: What are multiple dimensions?
« Reply #12 on: 25/03/2012 22:00:30 »
For those of us who grew up with the idea that a dimension was something that had to lie at right angles to any and every other dimension; an impression that comes from the fact that in every day speech a dimension is almost exclusively one of the three dimensions of space; it can be difficult to escape from the angular connotation.  However, if, for example, we talk of the dimensions of speed as being length and time, there are no angles involved.  So it is quite important to broaden our understanding of dimensions, and to think of them as those qualities or factors that are essential in defining whatever we are talking about.   Admittedly this does not tell you what 5 spatial dimensions would look like, but if you can find someone/something capable of doing that, PLEASE let me know.

#### The Naked Scientists Forum

##### Re: What are multiple dimensions?
« Reply #12 on: 25/03/2012 22:00:30 »