Time - the fourth dimension (2013 Flame Challenge) from Ira Glickstein on Vimeo.

My entry for Alan Alda's 2013

*Flame Challenge*was submitted last week. It is in the form of a short video answering the deceptively simple question "What is Time?" (click above to view the video).

Alan Alda is on a mission to help youngsters become interested in science. In conjuction with the Center for Communicating Science at SUNY Stony Brook, he started the

*Flame Challenge*in 2012 with the question "What is Flame?" They received some 800 entries.

I expect they will get even more this year with the question "What is Time?"

**ABOUT MY ENTRY**

I think I've come up with a unique way of viewing "

*Time*- the fourth dimension". Due to a strict limit on the length of the video, and the fact that it is aimed at 11-year old students, I have had to greatly simplify the material. This Blog posting includes additional material that will be useful to adult readers and science teachers who wish to know more about my way of viewing

*Time*.

There are three big ideas here:

is NOT a clock (any more than Space is a ruler or Heat is a thermometer), nor is it rotation of the Earth or motion or the order of events, etc.**TIME**is**TIME**, plain and simple. It appears different to us because the whole Universe is speeding along the*the fourth dimension**Time*axis at the speed of light.slows down when we move in Space because nothing can move faster than the speed of light, so any motion in Space must take away from the speed in**TIME***Time*such that the vector sum of the Space and*Time*velocities exactly equals the speed of light.

**WHAT**

*TIME*IS NOT*Time*is not the tick, tick, tock of a click, click, clock, any more than Space is a ruler or Heat is a thermometer!

*Time*the rotation of the Earth on its axis that gives us day and night divided into 24 hours. Nor is it the movement of the tilted Earth in orbit around the Sun that gives us the seasons, nor any other kind of motion. Nor is it the spontaneous decay of certain atoms that give radioactive materials a half-life. Nor is it simply the ordering of events.

**WHAT TIME IS**

*Time*, plain and simple, is the fourth dimension, very much like the first three dimensions of Space.

*Time*dimension appears different to us because you and I and the whole Universe are hurtling along it at very nearly the speed of light as a consequence of the “Big Bang” expansion some 13.7 billion years ago, in which our Universe, along with the dimensions of Space and

*Time*, originated.

Since

*Time*itself originated with the "Big Bang" it may not be meaningful to even ask the question "What happened

*before*the Big Bang?" In any case, we may never know what caused it.

*Time*axis, or at very tiny angles with respect to that axis. You and I, along with everyone and everything else, are still moving along or near that dimension at very close to the speed of light,

*, which is as fast as anything can go.*

**c***Time*dimension as motion because the whole Universe is moving along with us. Therefore, we notice only

*relative*motion between ourselves and other people and between ourselves and other things.

**WHY**

*TIME*CAN BE SLOWED A BIT*Time*where everything must move at the speed of light,

**, either along the**

*c**Time*axis, along a Space axis, or in a combination of

*Time*and Space at an angle,

**, to the**

*Θ**Time*axis. If movement is totally aligned with the Time axis,

**and we are said to be “at rest” in Space, and we move along the**

*Θ = 0**Time*axis at the normal rate (

*, about one foot per nanosecond).*

**c****, and we move through Space**

*Θ > 0**Time*in a combination of Space and

*Time*such that the vector sum of our Space and

*Time*velocities is exactly

*. Since nothing can go faster than*

**c***, any movement in Space must slow down our movement in*

**c***Time*. This was recognized over 100 years ago by Lorentz, Minkowski, and Einstein, who use the terms "Dilation of Time" and "Contraction of Space". This is usually expressed in terms of the Lorentz factor:

*is the velocity of light and*

**c****is the velocity of an object in Space.**

*v*

*As an engineer, I found that way of expressing relativistic effects of travel at significant fractions of the speed of light not to be "understandable" from my physical (and perhaps anal) point of view.**knocking my head against the wall*over an inordinate amount of

*Time*, I finally realized that I could get an exactly equivalent Lorentz factor by considering the angle

*, between the Time axis and the velocity vector of an object through SpaceTime.*

**Θ**[above image modified 12 April 2013]

*(the velocity of the object in Space) divided by*

**v****is equal to the**

*c***, and that 1/**

*Sin Θ**, the Lorenz factor, is equal to the*

**ϒ****.**

*Cos Θ***WHAT ARE DIMENSIONS?**

**SUMMARY**

When movement is a combination of

*Time*and Space, and the velocity in Space is

*, an object is moving through Space*

**v***Time*at an angle

*, such that:*

**Θ****, and 1/**

*v/c = SinΘ***(the Lorentz factor)**

*ϒ***.**

*= Cos Θ*The figure below shows the situation for seven different values for the angle of travel through Space

*Time*, from

*Θ =***to**

*0*⁰**.**

*Θ = 90*⁰

*Θ = 0*⁰ [*Sin**Θ = 0.0000, Cos Θ = 1.0000*] AT REST IN SPACE**For an object that is "at rest" in Space,**

**. Even when an object is not moving along the Space axis, it is moving along the**

*Θ = 0*⁰*Time*axis. Since everything in Space

*Time*must have a speed of

**, an object "at rest" in Space must be moving at speed**

*c***in**

*c**Time*. Note that for this condition,

**and the Lorentz factor**

*v/c = 0***. Note also that, for this case**

*ϒ = 1***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*Even the fastest rockets and satellites developed so far go only a tiny, tiny fraction of c. Therefore, for all practical purposes, the angle,

**, is ≈**

*Θ*

**0****⁰**(approximately equal to ZERO degrees).

**For example, the Earth is travelling around the Sun at a speed of 67,000 miles per hour, faster than any rocket, but that is only 0.001 % of the speed of light. At 67,000 miles per hour,**

*v/c*= 0.00001 and*Θ*= 0.0000017**⁰.**

*Θ = 15*⁰ [*Sin**Θ = 0.2588, Cos Θ = 0.9659*] MOVING 26% OF*c*IN SPACE**An object is moving through Space**

*Time*at an angle of

**. It moves through Space at 26% of**

*Θ = 15*⁰**and through Time at 97% of**

*c***. Note that for this condition,**

*c***and the Lorentz factor**

*v/c = 0.2588***. Note also that, for this case**

*ϒ = 0.9659***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*

*Θ = 30*⁰ [*Sin**Θ = 0.5000, Cos Θ = 0.8660*] MOVING 50% OF*c*IN SPACE**An object is moving through Space**

*Time*at an angle of

**. It moves through Space at 50% of**

*Θ = 30*⁰**and through Time at 87% of**

*c***. Note that for this condition,**

*c***and the Lorentz factor**

*v/c = 0.5000***. Note also that, for this case**

*ϒ = 0.8660***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*

*Θ = 45*⁰ [*Sin**Θ = 0.7071, Cos Θ = 0.7071*] MOVING 71% OF*c*IN SPACE**An object is moving through Space**

*Time*at an angle of

**. It moves through Space at 71% of**

*Θ =45*⁰**and through**

*c**Time*at 71% of

**. Note that for this condition,**

*c***and the Lorentz factor**

*v/c = 0.7071***. Note also that, for this case**

*ϒ = 0.7071***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*

*Θ = 60*⁰ [*Sin**Θ = 0.8660, Cos Θ = 0.5000*] MOVING 87% OF*c*IN SPACE**An object is moving through Space**

*Time*at an angle of

**. It moves through Space at 87% of**

*Θ = 60*⁰**and through**

*c**Time*at 50% of

**. Note that for this condition,**

*c***and the Lorentz factor**

*v/c = 0.8660***. Note also that, for this case**

*ϒ = 0.5000***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*

*Θ = 75*⁰ [*Sin**Θ = 0.9659, Cos Θ = 0.2558*] MOVING 97% OF*c*IN SPACE**An object is moving through Space**

*Time*at an angle of

**. It moves through Space at 97% of**

*Θ = 75*⁰**and through**

*c**Time*at 26% of

**. Note that for this condition,**

*c***and the Lorentz factor**

*v/c = 0.9659***. Note also that, for this case**

*ϒ = 0.2558***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***.**

*ϒ*

*Θ = 90*⁰ [*Sin**Θ = 1.0000, Cos Θ = 0.0000*] TIME STANDS STILLLight (and other forms of electro-magnetic radiation) move through Space

*Time*at an angle of

**. Light moves through Space at 100% of**

*Θ = 90*⁰**and, therefore, since nothing can go faster than**

*c***,**

*c**Time*stands still. Note that for this condition,

**and the Lorentz factor**

*v/c = 1.0000***. Note also that, for this case**

*ϒ = 0.0000***is equal to**

*Sin**Θ**and*

**v/c****is equal to 1/**

*Cos Θ***. Anything with mass cannot achieve this speed in Space because it would take an infinite amount of energy to get it up to this speed in Space.**

*ϒ***[ADDED 11 March 2013]**In response to some skepticism about my contention that the whole known Universe is speeding along the

*Time*dimension at nearly the speed of light, I did more research and found support from Brian Greene, Professor of Physics and Mathematics at Columbia U, who has been featured on the PBS Nova series. He writes:

**[Excerpt From: Greene, Brian. “The Fabric of the Cosmos.” Vintage Books, 2007. See http://www.pbs.org/wgbh/nova/physics/fabric-of-cosmos.htm for his PBS series.]**

*“Special relativity declares a similar law for all motion: the combined speed of any object’s motion through space and its motion through time is always precisely equal to the speed of light”*I have provided more detail in the first comment below.

*Ira Glickstein*