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

Infinite mass and energy.

  1. Nov 23, 2011 #1
    If a photon is traveling at the speed of light, wouldn't infinite mass and energy be a condition?
     
  2. jcsd
  3. Nov 23, 2011 #2
    It has no mass therefore zero mass times infinite mass still equals zero mass. However you would be correct in the case of an electron even though its mass is very tiny, when it is accelerated in a particle accelerator then it also would require infinite energy and acquire infinite mass if it travelled at the speed of light, so it can be accelerated to 99.9999% the speed of light and it takes more an more energy to keep getting it closer and closer, but as it's mass increased it requires more and more energy for smaller and smaller increases approaching but never attaining c.
     
  4. Nov 24, 2011 #3
    Makes you wonder what light really is.
     
  5. Nov 24, 2011 #4

    russ_watters

    User Avatar

    Staff: Mentor

    Light is light. As with anything, it is the compilation of all of its properties.
     
  6. Nov 24, 2011 #5
    This is precisely what I was investigating in this thread which has now been locked because someone put a very strange connotation on my "prove me wrong", which merely expressed a hope rather than a challenge. I have asked that the thread be reopened.
     
  7. Nov 24, 2011 #6

    russ_watters

    User Avatar

    Staff: Mentor

    Sorry, but those questions really don't have anything to do with science.
     
  8. Nov 24, 2011 #7

    Dale

    Staff: Mentor

    The thread was pretty useless, the lock was reasonable and re-opening it would surprise me greatly. Any time you have to use a "really" or "actually" in your question it is probably a non-scientific question, especially if you feel that you have to italicize or otherwise emphasize the word in order to properly ask the question.

    In my experience threads with titles of the form "What is X?", where X is a single word basic physics concept, generally wind up being locked with one or more of the participants being banned. I am glad that the moderators locked it before it got to that point.
     
  9. Nov 24, 2011 #8

    Dale

    Staff: Mentor

    We know exactly what light is. Quantum electrodynamics completely describes every aspect of light.
     
  10. Nov 24, 2011 #9
    better to get it nutted out once and for all in one thread otherwise this forum will have endlessly questions like

    ceaselessly posted by lay persons.
     
  11. Nov 24, 2011 #10
    QED explains interactions, not photons.

    I guess you subscribe to the idea of; "shut up and calculate." Or "light is light", or "gravity is gravity."

    Keep on calculating, have fun.
     
  12. Nov 24, 2011 #11
    How would you know that?
     
  13. Nov 24, 2011 #12
    When an investigation into 'what is matter', which had some good replies and to which I was about to offer a considered response, is deemed unsuitable for a physics forum as it is beyond the abilities of the moderators to stop such a contentious question collapsing into peace shattering conflagration, then one may wonder what the point is of allowing the general public to participate at all. This is most disappointing.
     
  14. Nov 24, 2011 #13

    Matterwave

    User Avatar
    Science Advisor
    Gold Member

    Since observations are interactions, and all of physics is about interactions, I'm not sure what kind of an explanation you want if the one offered by QED is not acceptable.
     
  15. Nov 24, 2011 #14
    "Makes you wonder what light really is."

    I think scientists are those who dare ask such questions.

    How this forum can inspire young people to go into science is in my opinion not by putting down those who ask such questions even if they are laymen.
     
  16. Nov 24, 2011 #15

    Dale

    Staff: Mentor

    QED explains everything about light. There is not one single behavior or experimental observation about light which is not accurately predicted by QED.

    If you can predict in detail what a given thing will do in every possible situation or interaction or relationship then you know what that thing is in the fullest sense of the word. Hence, we know exactly what light is.
     
  17. Nov 24, 2011 #16
    But this is an answer to a classical question but a photon is a quantum object. This in essence is the problem is it not.

    So in answer to 'what is a photon' the answer is that it is an electomagnetic wave, that may set off detectors that see it as a wave or as a particle depending on what type of detectors are used.

    Which brings us right back to the real problem, which is comparing a quantum object to a classical object. To ask what a classical object is, is a perfectly acceptable question. What is a baseball, or what is a mountain. Most people will be satisfied with the answer. However the scientist is willing to answer the question, 'what is a baseball REALLY', by saying that REALLY, it is in fact a collection of up and down quarks and electrons, plus a couple of forces that hold them all together.

    There is no problem with the word 'really' in this case.

    It only gets the mentors all hot and bothered if one asks, but what is a quark 'really', this 'really' is really a pain and causes all sorts of huffing an puffing.

    Ironically, because one of the foundations that all science is built on it the principle of relativity. What is relative and what is absolute needs to be considered when using the word 'reality'.

    This is why it is preposterous for a science advisor on these boards to complain about being asked 'what is matter, or what is a photon, really (even if the 'really' is not italicised).

    You see the concepts of 'relative' and 'absolute' are also applicable to terms like 'reality' or 'real'. Is a photon 'real'. No one seems to consider the question is really about what is meant by 'real'. I think what we mean by real in this context is, what is 'absolutely' real.

    That is for example if I use a photon. Is a photon absolutely real. Asked like this it is a perfectly acceptable question. I suppose the next question is what does it mean to be absolutely real. And that would be as the speed of light is absolutely real because it's speed is not dependent on anything else, then for something to BE absolutely real, then 'be' means 'exists', so the question is, does a photon exist absolutely, or does it's existence depend on the existence of something else.

    That's what we really want to know, when we ask 'what is matter'. Science reduces atoms to protons and protons to quarks, so atoms depend on the existence of protons and protons depend on the existence of quarks, and I suppose electromagnetic radiation may or may not depend on the existence of something else in order for itself to exist.

    No I'm trying my best to keep this out of the realm of metaphysics because then I'll get a slap. However, the scientists started it all by reducing objects to things that are dipping their toes into the pool of metaphysical notions in fact maybe even wading in to the deep end.

    Is there anything that is absolutely 'real', meaning that exists independently of anything else. Surely that's an OK question here. Otherwise why don't you put up a big disclaimer that says... "look we really don't have the faintest clue what any of this stuff that we study is, we can predict how it behaves and that enables us to build this big a55 five story high detectors and it's pretty much a lot of fun but in the end we are just amusing ourselves with the amazingness of it all, and you people out there should be content with your cars and computers and digital painting programs and microwave background plotting, that enrich your lives and which are the final products of our investigations.
     
    Last edited: Nov 24, 2011
  18. Nov 24, 2011 #17

    Dale

    Staff: Mentor

    If one good thread were enough to end a topic "once and for all" then we wouldn't continue to see the daily thread on a photons rest frame, the weekly thread on the twin paradox, the monthly thread on FTL communication with a rigid rod, or the quarterly thread on something fast turning into a black hole.
     
  19. Nov 24, 2011 #18

    Dale

    Staff: Mentor

    Thank you for illustrating my point so completely.
     
  20. Nov 24, 2011 #19
    If we know what light is then surely it's OK to ask, 'what is light made of'. QED predicts how it interacts and behaves, but what is it made of. That's what the general public wishes to know. Are you going to tell people. "you can't ask what's it made of, it's a stupid question". To which one could postulate that there are no stupid questions, only stupid people.
     
  21. Nov 24, 2011 #20
    Ok Dale, draw a line in the sand for me. Where does science end and metaphysics begin. Are virtual particles metaphysics or science. Is 11 dimensional space, simply mathematics, metaphysics or science. Is asking what is a gluon made of allowed or not allowed.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Infinite mass and energy.
  1. Infinite mass (Replies: 2)

  2. Infinite mass? (Replies: 12)

Loading...