Thanks for correcting me, and I have been out of touch with Physicists from Institute where I worked for 20 years, and then there were no Synchrotron, at least not at this Institute.........

I also wrote Neutron when I thought of Positron, and that was in the middle of the night so I was tired, sorry.....

Anyhow, long and short of my discussion is that mass do not change with speed, and that energy is just added to mass, so it would be more correct to have some unit of measurement like Kg * v where must be v > 0 but since Kg is always 1 it could be written as Kgv, but then problem is that 1Kg is weight unit and is same only at 1G, but I think it should be treated to be same >>as it is at 1G<< even in weightless condition, as it is manifested as inertia. But we have problem because Inertia is considered to be force, right? But then also there is two kind of inertia, Inertia of position which opposes to forces that would move mass, and Inertia of movement where it opposes forces that would stop movement of the mass......

At least, that is what I was taught long ago, if I still remember it correctly.....

Now, is it same Inertia, positive in movement and negative when there is no movement, or it is case of two different forces?

Since speed v cannot be negative, adding positive and negative force cannot create movement, but we have such case where inertia overcome force of impact and energy rebound, changing direction, but some of it would be added to mass raising its energy level trough temperature........

So, to describe mass, we have to know its dimensions, specific weight, speed of movement, temperature, gravity influencing it, gravity produced by it, and direction it is traveling if it moves.

From this we would then be able to calculate its inertia and impact energy, which is actually equal to positive Inertia.

So, I would say that accelerating mass produce positive inertia which grows with speed, and is equal to impact energy in direction in which mass is traveling.

At same time, we have negative Inertia in diametrically opposite direction, exactly of same size, and resultant force of interaction of mass and external force is calculated through Vector arithmetic between forces in interactions.

But we have >>conditional<< calculations if we would like to calculate outcome of impact, or in fact we can or cannot calculate, that is, there is interaction between force and mass, or there is not......

For instance, mass and force on same vector and going in opposite direction can interact only if there is some point on this vector that both would reach in some future time unit, or if mass and force travel in same direction and force is behind mass and has greater speed.

Opposing forces would create product equal to difference of energy, and this difference would be changing energy of mass and its direction of traveling.

Equal forces opposed would cancel movement, so we should in any case just add energy of Inertia as positive and energy of force as negative.

If results is positive (including zero) then it is simply replacing mass inertia forces in same amount on positive and on negative side of vector. Then, it seems we don't need to have two forces, as one amount of Inertial energy should be considered positive in direction of movement and negative in opposite vector, and when there is no movement, inertia is equal to weight, treated as positive in direction of applied force, and applied force as negative, because any impact on one side that has greater energy than inertia of mass would push mass in negative direction, away from impact, right?

All other cases where mass with smaller speed is following greater force (and therefore speed) or smaller force is following mass with higher speed result in no interaction...

From this could be seen that faster spaceship is going more energy should be applied to produce reactive force that would push ship still faster in opposite direction, and since even with greatest possible speed in reaction drive, one that would emit light, speed cannot be greater than speed of light, and practically it would be smaller.

With proper energy source, therefore Light Speed can be almost reached, and for faster than light travel, we would have to have Neutrino drive :-))

So, what it all has to do with E = mc2 formula?

It is obviously atomic energy formula, or total energy of atom, so there should be atomic weight as a mass to be correct :-)

Also, there c must be speed of light and cannot be any other speed.........

If applied this way, then we can see that greater atomic mass is, greater energy is contained in that atom, or that greater energy is used in fusion reaction, greater atomic mass would be produced, but only with limitless energy can limitless atomic mass be produced, and that look to me as >>primal atom<< of >>Big Beng<<........

So, there is no way that mass can grow with speed of its traveling, and Einstein formula would be useful to know how much energy we can convert to Photons, once we would be able to do conversion and use this process as photonic drive, or even produce Neutrinos and travel faster than light, if we can live at such speed, and if atoms of spaceship would not be >peeled< off layer by layer.........

I apologize to all that know more Physics than me, and if there is mistake in my reasoning please correct me.........

So, to describe mass, we have to know its dimensions, specific weight, speed of movement, temperature, gravity influencing it, gravity produced by it, and direction it is traveling if it moves.

I would suggest you read again the basics of physics or at least of classical mechanics: mass is an independent property of mater!

Weight is a force and depends on the acceleration field in which the mass is present, for instance the SAME MASS will have different WEIGHTS on the Earth, on the Moon, on Saturn or in other attraction field. The fact that there is no field does not change the amount of mass. In space the mass is not modified only the attraction forces are less. The "kg" is the unit of MASS in today's metric system it is a basic unit, force has as unit the "N"(ewton) defined as the force which will give to a mass of 1kg an acceleration of 1m/s².

The POSITRON is the mirror of the ELECTRON same mass but the charge is + in stead of -

There are more corrections to make but so many that it will be better you read again before making such discussions, you mix notions and meanings you invent notions as "negative inertia" which does not exist inertia is a scalar property and has no direction being not a vector.

An impact can be calculated if you take care of the kind of bodies coming to a dynamic contact and how energy is exchanged between participants. A force cannot "follow" a mass at higher or lower speed.

The definition of a force is the time first derivative of the product "mass*speed" in the case of a space ship in general the speed is a constant (of ejected gases) and the ship mass decreases versus time.

The Neutrino is a particle with a mass of same order of magnitude as electron or positron but with no charge as the neutron.

So, there is no way that mass can grow with speed of its traveling, and Einstein formula would be useful to know how much energy we can convert to Photons, once we would be able to do conversion and use this process as photonic drive, or even produce Neutrinos and travel faster than light, if we can live at such speed, and if atoms of spaceship would not be >peeled< off layer by layer.........

Before you criticize Einstein and others you should first understand the basics of the theory.

Yes, You are right and i am rusty all over........

I am also not Physicist nor Engineer for mechanical systems, and my knowledge is 50 years old, nearly........

Of course that force cannot by itself go in front or behind a mass, and usually force is tied to some mass even if this are Photons.....

But one example of weaker force following mass would be motor boat with wind blowing from behind, or aeroplane flying down the wind, obviously kinetic force contained in air movement cannot influence mass going in same direction faster, right?

I must confess You confuse me, as we were taught that weight is a property of mass, as is volume, temperature, speed....

Ah, that modern time....... Everything has changed!

Till now I lived using Kg as unit of weight, and I never used Pounds and other English measures like Foot, Yard.......

I thought Newtons were units for measuring work done, that replaced HPs, that is Horse Powers......

But from way You define them, they are what I wanted to name Kgv.........

We were taught that there is two kinds of Inertia: one that resist to movement of body from present position and one that resist change of direction of movement, like for instance gyroscopic force that resist change to plane of rotation (if it is still called this way, that is).

So if by using my concept of positive and negative Inertia we can unify this to be just one force depending on direction, and if we can get same results in calculations as they are in reality, then such concept would be practical, no?

As you see, I managed to make same explanation why it is hard to reach speed of Light, without introducing concept of growing mass.....

I did not want to criticize Einstein, but tell what I think, and all started with that remark that mass is growing with speed......

But if mass is imaginary property that is just result of calculations, where one element is speed, then inevitably mass would seem to grow with growing of speed.

I seems to remember now that we have two kind of mass: Physical and Mathematical or something like this.

If You have read carefully, You would see that I mentioned that weight depend on Gravity, counted as 1 on our planet, so I agree that weight change on the Moon, or in orbit around the Earth.

With this >>Acceleration Field<< You really beat me, and I see I would have to learn things all over, as I first time hear about it.

But then also, English in not my Native language, so I lack proper words, specially such as used in some specific trade as each has its jargon, right?

Thanks for comments, I appreciate your efforts to help me understand things better!

Thank you, thank you.