Can relativistic mass be treated as rest mass?

It seems clear, pointed, and of broad interest. I doubt most introductory students of physics could answer it without thought.

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    $\begingroup$ Your question got one downvote, and since you posted this it has attracted one upvote so its net score is zero. Was that one downvote worth a Meta post? $\endgroup$ Jul 5 '16 at 5:22
  • $\begingroup$ It got a negative reception because of the long chain of comments. $\endgroup$
    – Will
    Jul 6 '16 at 4:50
  • $\begingroup$ @Will try not to get discouraged Will. Some of us understand that ot can take some time and discussion to become convinced or learned of a topic that was previously misconcieved by you. All of us at some point have had the wrong understanding of something or other $\endgroup$
    – user122066
    Jul 7 '16 at 19:26
  • $\begingroup$ @Will i also think a meta post is apropros for this as a discussion like we're having is not appropriate in the physicsSE. Dont let fussy people get you down or discouraged and please continue asking questions and focus on your education and personal growth! :D $\endgroup$
    – user122066
    Jul 7 '16 at 19:28
  • $\begingroup$ @Will there are lots of different cultures here and hence disagreements on a variety of of methods people use in their personal questfor education. Dont sweat it. Maybe ask some simple questions or answers to start out with in order to build your repuration? $\endgroup$
    – user122066
    Jul 7 '16 at 19:31
  • $\begingroup$ Also, i up voted for you simply because this is meta and i dont see any reason why you shouldnt be allowed or punished for asking this qiestion. I dont get it /shrug $\endgroup$
    – user122066
    Jul 7 '16 at 19:33

I've just added another (just second) negative vote to the original question once my suspicion was confirmed: It is not really a question, it is an attempt to promote obvious misconceptions about relativity.

Dmckee gave an answer (which I upvoted). Some of its general lessons are:

  • One should discuss the energy-momentum vectors, not just "masses and velocities" to meaningfully describe collisions in relativity.
  • The final motion of products of elastic collisions is determined from the dispersion relations; and from the energy-momentum conservation law.
  • The rest masses of composite systems aren't additive as you demonstrably kept on assuming.

He also added technicalities but these three key observations should have been enough for you to try to refine your wrong "derivations". But you, Will, just ignored everything in the answer and continued to promote your misunderstandings. When I realized that you ignored the answer, my suspicion was confirmed and I downvoted your question.

I also downvoted your "answer" to your own question because it doesn't answer the original question what happens in the collision. The answers should answer the original question. When they don't, they may be reasonably downvoted, even if we ignore the "awkward" fact that the author of the answer and the author of the question are the same person.

Here on the meta-website, I downvoted your question because I find it absolutely unacceptable for users to complain about every single negative vote they receive, especially when it must be pretty much obvious to them that there are very good reasons to downvote these questions and answers. That's how spoiled brats, not constructive users of a questions-and-answers website, behave.

By these negative votes (for which I sacrifice -1 of my reputation, so it's not for free), I am giving the system some information which is service to the community, too. One of the reasons of the negative vote is that I want you to discourage from posting additional questions and answers to this server because I am gradually concluding that additional contributions of yours won't lead to anything positive.

  • $\begingroup$ But the whole point of asking a question or posting about a topic is to obtain an answer is to address and remove misconceptions! Learn and grow. I seriously doubt a person is on stack exchange in order to create or spread misconceptions. Most likely this person was obviously confused on this topic and people more capable on the subject fixed his/herisunderstandings. $\endgroup$
    – user122066
    Jul 7 '16 at 19:21
  • $\begingroup$ i.e. sometimes people have different ways of communicating due to different cultures/languages. Id be more concerned if they were providing answers to questions but that is where the whole voting process comes in. If soeone is downright wrpng about an answer itll be downvoted into oblivion. Im personally not convinced there are ever bad questions :D $\endgroup$
    – user122066
    Jul 7 '16 at 19:23
  • $\begingroup$ Furthermore, it often takes some people quite a while to become convinced on something theyd previously known to be different. We can mever expect someone to agree immediately with an answer. Just my perspectives on it all. I dont want people to be discouraged here $\endgroup$
    – user122066
    Jul 7 '16 at 19:25
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    $\begingroup$ @user122066 : Nobody fixed Will's misconceptions. As Lubos pointed out, he is not listening to the Answers and comments, he is not "learning and growing". He posted almost the same question 2 days later (physics.stackexchange.com/q/266601). $\endgroup$ Jul 8 '16 at 4:18
  • $\begingroup$ @user122066 - I agree with Sammy. What you, user, write is a desire, it's how things should be. Except that in many cases, it's obvious that it's not how things actually are. I think it's essential for every rational person - and user of SE - to distinguish a wishful thinking from the reality. In some cases, users are extremely unlikely to "grow" either because their background/intelligence is hopelessly bad or because they aren't willing to listen - and prefer to argue, or both. In those cases, it's good if they get downvoted or questions closed to save the constructive users' energy+time $\endgroup$ Jul 8 '16 at 8:57

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