Imaginary Velocity?

[NegativeGPA]

So, according to my understanding,

m= m_o/√(1-(v^2/c^2 ))

gives the mass of an object in respect to the object's original mass and its velocity. I wondered what happened if the mass of an object became lower than the rest mass? [I have no idea how this would happen, but it was a, what if it did? kind of question]

I made the substitution m=m_o-a for some arbitrary amount lower than the rest mass. After solving the equation for velocity, i got

v=c√(1-(m_o^2/(m_o-a)^2 )

in the equation, you can see that,
(m_o-a)^2 < m_o^2

thus,
(m_o^2/(m_o-a)^2 > 1

so we would end up with the square root of a negative number, giving the object with an imaginary velocity.

This matched my predictions because the reason I wondered this was because I wanted to know what was so special about the rest mass of an object. Why is that amount of energy in that amount of space a particle, and why does additional energy cause what we call velocity? So i assumed that a lower amount of energy would do somehow the opposite of velocity, but what is that?

[Kevin_Axion]

I'm not sure exactly what your asking but this could help:
When the rest mass of an object becomes imaginary this is the description of a Tachyon: http://en.wikipedia.org/wiki/Tachyon
The Tachyon's velocity would hence be super-luminal.

[NegativeGPA]

Haha thanks, but I'm talking about an imaginary velocity, not an imaginary mass.

I'm asking what would happen if an object's mass became lower than its rest mass, and apparently it has an imaginary velocity. I'm asking if anyone has any idea what that means

[Kevin_Axion]

A simple Google Search would suffice: http://sci.tech-archive.net/Archive/sci.physics/2008-04/msg00062.html