user62511

@parisa: yep i understand.

Peter is not present. really eerie.

These are sons of Banach and Tarski: kevincarmody.com/humor/1213orig.gif

Let $a_n$ denote the maximum number of people in year n (eg. 2013). Finite future will not determine whether $\sum_{n=1}^\infty a_n$ is convergent. So is there any way to prove or disprove its convergence! ? ( What I tried: I tried epsilon delta definition but i failed)

that's also arbitrary.

yep. arbitrary set.

two sets have intersection iff they have a common point.

Hi, Let A be a set. what's your suggestion to create a set B with cardinality |A| such that B and A have no intersection.

@BySymmetry: What if the other end is connected to the positive end of the battery?

Let me ask another question about a battery. Suppose a thick very long (10^10000 meters for example) wire is connected to a lamp and the other end of the lamp is connected to the negative end of the battery. Will the lamp light and will it use up the battery? The other end of the wire is free.

@BySymmetry " so everyone must agree on that" well I think a single electron will decide if a contant is open and if it pass through a toucher.

Let me ask a question about the battery. Is the negative end of the battery a place with crowded electrons? So when they see a wire they fill it?

@BySymmetry: What's wrong with this argument?

2) Suppose the negative end of battery is connected to the right toucher. When left touchers link, right toucher are not connected for the battery so electrons do not do anything noticable. When right touchers connect, electrons enter set 1 and keep going until they reach the other end, which is linked wrt set 1. and this process keeps working for 2 seconds after which left touchers disconnect. So both lamps will be on (each for 2 seconds).

1) Suppose the negative end of battery is connected to the left toucher. When left touchers link electrons enter set 1 and keep going until they reach the other end, which is linked wrt set 1, so the electrons reach the positive end of the battery. and this process keeps working for 2 seconds after which left touchers disconnect. So both lamps will be on (each for 2 seconds).

@BySymmetry People have different opinions about what happens next, I cannot accept them axcept they have scientific reasons. What do you mean by pulse? After the circuit is closed for set 1 a continuous flow of electrons from the battery will keep the lamps on until set 1 lose the links. correct?

so if the simultaneous link for set 1 last for 2 seconds both lamps will be on for 2 seconds? correct?

btw, I enjoy this discussion, but I think that answer, answers a different question (about too sharp touchers)

It seems you did not know this main question while you wrote this anwser: physics.stackexchange.com/a/130083/56257. If so, isn't it better to edit that answer (if you have a better one more compatible with the question)?

On the other hand the battery will never feel any closed circuit. Why should it lose energy if lamp 1 is to be on for 2 seconds.

Let me rephrase: lamp1 can feel the closed circuit for 2 seconds if the sizes are changed appropriately. Why won't it remain on during the 2 seconds-long link?

@BySymmetry you said they will flash. But lamp 1 can feel the closed circuit for while and it seems it should remain on until the circuit is open again.

I do not say that "electricity only flows in a closed circuit" but I believe "electricity flows in a closed circuit" and for lamp 1 the circuit is closed. why do you say that lamp 1 will not light?

@BySymmetry: Is there anything vague in the experiment describe? The comments show many people have problem with it!

I have some experiences with circuits. see this eg: electronics.stackexchange.com/questions/124230/…. btw I think relativity plays the main role in the question. I asked a question: lamp 1 will feel 2 ends of a battery for a while. What will happen? Jim said something interesting: The electrons from the battery will not feel the closed circuit so why should they move towards lamp 1? How do you describe this closed circuit for set 1?

Really the answer seems more suitable for set No. 2 where there is no closed circuit. For set No. 1 I cannot imagine clearly.

I read again. Still a vague situation. I have asked this question that which lamp will light several times on the internet. Everyone has a different scenario about which lamp will light (e.g. see this answer for example). Really confusing. btw, the argument about flashing and electrons seems reasonable (=I cannot claim anything is wromg with it although it is vague for me). you transformed the question for me to "How electrons move in this situation in each frame?". I should read more about how electrons move in relativistic situations.

I should re-read your answer tomorrow. It seemed to be reasonable. btw, it seems strange: for set 1 the circuit is closed for an interval of time (which can be elongated if the numbers change appropriately) but the lamp will just flash. I thought one of these will happen: 1) no lamps will light, 2) both will light, 3) just one will light. But flashing was not something I could imagine

btw, I don't understand why electrons pass throught a wire (=set 2) when only one toucher is connected to it.

"you don't need a closed circuit for an electric current to flow and transmit energy" OK, this seems to be a start of a scientific answer. Suppose your are in Set 2. you'll see a wire coming with a high velocity which is too short to close the circuit. But it closes. That seems reasonable. Can you explain this with formulas or with more convincing details about how this can happen? (a silimar well-known experiment, a wikipedia page, a paper, etc can be convincing).

Why will lamp 2 flash while in frame No. 2 there has been no closed circuit? How can it light in an open circuit?

@BySymmetry: Can you tell me which lamps will turn on in the situation described?

"That drastically changes" No. As noted numbers are unimportant. The situation is the question. change numbers if they are not good as you wish as long as the situation described persists,

@KyleKanos "by enlarging" $10$ m to $10^5$ m and using larger touchers it may.

"Your problem is that you are assuming that the information about the circuit being closed is transmitted instantaneously to all point" this is correct but it is marginal. the touchers are not a sharp point. Also by enlarging the lengths it may be possible to let the closed circuit persist for 10 seconds for example. So please ignore it. The question is about sources of energy.

Probably only English has official nicknames!

I'm not Chinese but I think so. But they may be immigrants. I want to know why Bruce Lee is Bruce!?

that's interesting. I thought Bill is his real name. No. I'm Asian.

@Cerberus How about Bill Clinton. Is his official name William Clinton?

I also want to know: Which nickame is used? When can we use a nickname? Can nicknames be offical names e.g used in an ID card? etc.

So it must be too common because you never thought about it. btw, I don't think all Richards like their name! ;)

But you don't say Richard! :) That's too strange. Isn't it a shame for Richards!?

en.wikipedia.org/wiki/Dick_Tracy.

How can you use a taboo as a man's name? That's strange. Isn't that bad!?!

Use C++! ;)

Unfortulately SE has not PM. Note however by PM one can mean "Prime Minister" or "Private Message". btw. the problem is PM. which does not mean Public Media. or public chat room. OK, it's 21:00 pm. It's time to sleep. goodnight everybody! (In this episode of my dreams Imna send another mechanical dog to catch Chobin so please don't send me any messages I'm too busy). ;)

OK. mamnun. Or anything you like, However I'll catch Chobin!

Echo: hi

hi

@DanZimm: it seems a too long discussion for a too trivial equality ;)