Re: [Phys-l] Invariant mass and relativist mass...

[carmelo@pacific.net.sg]

Quoting "LaMontagne, Bob" <RLAMONT@providence.edu>:
> The problem with using "relativistic mass" is a matter of which   
> "relativistic mass" you are going to use: longitudinal, or   
> transverse. The usual formula with the square root in the   
> denominator is really for forces perpendicular to the motion. To   
> correct a pendulum, and use the concept of force and mass, requires   
> a 3/2 power in the denominator - better to stick with non-scalar   
> momentum, total relativistic energy, and rest mass.


The fact is many Nobel Laureates amd prominent physicists have adopted  
Relativistic mass. Just to mention a few...

1. Leon Lederman (Nobel Laureate 1988) The God Particle: If the  
Universe Is the Answer, What Is the Question? (Houghton Mifflin, 1993)  
p. 205 “When the particle is accelerated its energy, E, and hence its  
mass increase.”

2. Robert Laughlin, (Nobel Laureate 1998) A Different Universe:  
Reinventing Physics from the Bottom Down (Basic Books, 2005) p. 119  
“the weight gain acquired by objects moving at high speeds and the  
equivalence of mass and energy, are now routinely verified in  
laboratories all over the world”

3. Martinus J.G. Veltman (Nobel Laureate 1999) Facts and Mysteries in  
Elementary Particle Physics (World Scientific Publishing Company,  
2003) p. 137 “Take a car, weighing, say, 1000 kg. Bring it to a speed  
of 100 km/h. The weight of the corresponding energy..."

4. Gerard ‘t Hooft, (Nobel Laureate 1999) In search of the ultimate  
building block (Cambridge University Press, 1997) p.17 “Mass and  
energy in this theory also depend on velocity.” "Modern physics  
teachers prefer to redefine mass such that it is velocity independent."

5. Julian Schwinger (Nobel Laureate 1965) Einstein's Legacy: The unity  
of space and time (Dover, 2002) p. 84 “But, when the speed has reached  
a value near c, and can no longer increase very much, the momentum  
still continues to grow because the mass gets larger.”

6. Richard Feynman (Nobel Laureate 1965) Perfectly Reasonable  
Deviations from the Beaten Track, (Basic Books, 2005) p. 283 “It was  
successful, the necessary consequential phenomena (like mass changing  
with velocity) were ultimately observed experimentally.”

7. George Smoot (Nobel Laureate 2006) Physics 139 Homework, url:  
http://aether.lbl.gov/www/classes/p139/welcome.html

8. Stephen Hawking, A Brief History of Time (pg 20-21) “Because of the  
equivalence of energy and mass, the energy which an object has due to  
its motion will add to its mass. In other words, it will make it  
harder to increase its speed.”

9. Michio Kaku (2004) Einstein's Cosmos “For example, Einstein could  
show that the mass of an object increased the faster it moved. (Its  
mass would in fact become infinite if you hit the speed of light—which  
is impossible, which proves the unattainability of the speed of  
light.) This meant that the energy of motion was somehow being  
transformed into increasing the mass of the object. Thus, matter and  
energy are interchangeable!”

10. John W. Luetzelschwab (2003) "Apparatus to measure relativistic  
mass increase", American Journal of Physics, 71(9), 878.

11. Gerald Gabrielse (1995) "Relativistic mass increase at slow  
speeds", American Journal of Physics, 63(6), 568.

12. Olson, D. W. & Guarino, R. C. (1985). “Measuring the active  
gravitational mass of a moving object,” American Journal of Physics,  
53 (7), 661.

Recently, I have purchased some textbooks written for IB Diploma such  
as K.A. Tsokos or Tom Kirk, also adopt relativistic mass. The syllabus  
of University of Cambridge Local Examinations Syndicate's still  
includes relativistic mass. And as John Denker mentioned earlier, this  
is not a technical issue.


Alphonsus