Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is the difference between Boost and Translation?

  1. Apr 10, 2014 #1
    As we face in Poincaré Transformation, there are boost and translational symmetry.What is the difference between these two terms?
  2. jcsd
  3. Apr 10, 2014 #2


    User Avatar

    Staff: Mentor

    A "boost" changes an object's velocity. A "translation" merely changes its position.
  4. Apr 10, 2014 #3
    Thanks for the reply. So basically boost is a change position with acceleration?
  5. Apr 10, 2014 #4

    Filip Larsen

    User Avatar
    Gold Member

    I always read "boost" as short for "Lorentz boost" and simply meaning the Lorentz transformation for a given velocity (speed and direction). For what it is worth, Wikipedia [1] seems to agree with this, with the addition that a boost is a rotation-free Lorentz transformation.

    [1] http://en.wikipedia.org/wiki/Lorentz_transformation
  6. Apr 10, 2014 #5

    Meir Achuz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    No- with constant velocity
  7. Apr 10, 2014 #6


    User Avatar

    Staff: Mentor

    We're simply changing coordinate systems. No acceleration of the object is involved.

    In a translation, the initial and final coordinate systems simply have different origins. There is no relative velocity between these two coordinate systems.

    In a boost, the final coordinate system has some velocity relative to the initial coordinate system. The origins of the two coordinate systems often coincide at t = 0.
  8. Apr 11, 2014 #7
    Thank you jtbell,Filip and Meir. :)
  9. Dec 4, 2015 #8
    More generally "boost'" can be a change in acceleration or in force or in power.
  10. Dec 4, 2015 #9
    More generally a "boost" can be a change in acceleration or in force or in power.
  11. Dec 4, 2015 #10

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    No. As stated before, it's a change in velocity.
  12. Dec 5, 2015 #11


    User Avatar
    Science Advisor
    Gold Member

    Putting the term in context: Mostly, the engines of a spacecraft are off and acceleration from them is zero. Boost, involves turning them on, (often for a short time) which will change the velocity almost instantaneously (compared with the time period of the orbit). If you're lucky, the acceleration will be constant during the period of the boost but, for a long burst, the mass of the craft will be reduced and so the acceleration may well increase during the burst time.
    It strikes me that the context of the passage where the term is used will give a clue as to the details of what is meant.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook