0
$\begingroup$

There is a question that goes:

Suppose you are told that the linear size of everything in the universe has been doubled overnight. Can you test it by using the fact that the speed of light is a universal constant and has not changed? What will happen if all the clocks in the universe also start running at half the speed?

My doubt is with the approach that whether this can this be answered using Mass? Since that remains unchanged? If so, how? And if not, Why not?

Improve this question
$\endgroup$
4
  • $\begingroup$ Possible duplicates: physics.stackexchange.com/q/721 , physics.stackexchange.com/q/47259/2451 and links therein. $\endgroup$
    – Qmechanic ♦
    Commented Mar 16, 2023 at 7:03
  • $\begingroup$ The linked questions don’t answer the doubt about mass which seemed like a good approach to me. The answer below by Naveen V clarifies that directly. $\endgroup$
    – YPS
    Commented Mar 16, 2023 at 8:41
  • $\begingroup$ I suppose the sudden change overnight you mentioned has to do with the magic spell that is to be broken at midnight. Usually this sort of cosmic phenomenon would leave some kind of experimentally measurable traces such as a glass slipper. $\endgroup$
    – MadMax
    Commented Mar 16, 2023 at 14:34
  • $\begingroup$ @MadMax Maybe something from MCU lol, the glass slipper’s too basic. $\endgroup$
    – YPS
    Commented Mar 16, 2023 at 17:46

1 Answer 1

Reset to default
0
$\begingroup$

The question is very vague to use it with mass , first case everything is doubled and the mass of an object remains the same and is more widely distributed decreasing density ( highly unlikely sometimes this breaks the object because bonds could be weak) , hence the second case is If an object doubles its length it must acquire some new mass , it cant be unchanged through the doubling of sizes is what I think. You can check it via the speed of light because it is an universal constant and doesn't change in any reference frame and we can use that to measure the doubling of sizes overnight , and if clocks also run at half speed no difference is found as due to special relativity the reference frame with which light travels a greater distance than normal , its time must increase to compensate. When the increased time is compensated by the decreased clocks , we wouldn't notice anything

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.