# swaha

Senior Members

159

1. ## can anybody show me the proof of fourier series?

well i didnt find it anywhere, please help me with sites where to find the proof if u wont like typing. well its easy to understand that if the rhs is true the lhs will be a periodic function for the lcm of the period remains same not the vice versa. plese give me the proof.
2. ## The Uncertainty Principle

did u mean that we are uncertain not by laking instruments but shall always be? but why cant we measure correctly if we can make an errorfree instrument? please explain.
3. ## Through which medium does light travel.

electric & magnetic fields oscillate so it's got a frequency.
4. ## SFN User Award Winners 2008

isnt there a best questioner category? i mastered it probably, making others really sick with my questions. but y was mr swanshot's name not included?
5. ## what was there?

ooops. it's point. sorry, dont ban me please.
6. ## Photon

how do we know the math & models are correct then?
7. ## a problem regarding interference.

ok. what if we dont allow them to interfere instead let them fall on two different points so that we may observe the pts. now how can the same light make two things visible at different places at the same time? does it mean if light diverges from a pt all photons it carried do travel simultaneously in all beams? what's wrong in supposing half of the photons in one beam & the other half in other beam? after all the intensity does reduce the same way. it wasnt clear sir. please explain & send me the links, name of books what i should study regarding this.
8. ## why is time called 4th dimension?

thanks. i get it. we probably cant imagine it geometrically.
9. ## Photon

pls dont mind but if we really cant visualize something how can we explain? how do we know?
10. ## what was there?

if universe was a pt at the time of bigbang what was outside that pt? what was before that time?
11. ## why is time called 4th dimension?

we can see only three mutually perpendicular st line in space at a pt. if time was another dimension either we have to imagine it only or we must shrink the angles. but what is the reason of shrinking the angle? infact what is the significance of another dimension? pls explain.
12. ## what is a quark & lepton?

actually wen i first entered the forum i saw a name appear lepton now its quark? well i think its got 2 do soth with atomic physics. can somebody tell me what those are? both in reality as well as wht we are meant here?
13. ## Escape the earth

what is hoghmann transfer orbit? can anybody give me the deduction for minimum energy? or tell me where to find it pls. i am a 1st yr stdnt of physics only.
14. ## Which dries faster ?

black one of course if there is light around otherwise same.
15. ## a problem regarding interference.

how can u say light has quantized energy? what is localized light? i think it never stops. Merged post follows: Consecutive posts mergedeven if light is quantised being a wave how can a photon interfere with itself? if it has to do so it must be present in both the beams simultaneously. bt how can 1 thing be at 2 different palces at the same time?
16. ## A Universe without Time

how can u observe time without light? light signals from a pt where an event occurs reaches u & u can start measuring time. otherwise how do u understand the interval? i think light's velocity is more fundamental.
17. ## how was speed of light measured?

no problem. we can still try to know what light would itself observe.
18. ## what do you observe?

a light particle/ soth moving in speed of light must be at rest wrt itself. nothing can say that its really moving. i just wanted to understand its observation.
19. ## what do you observe?

is there any problem in assuming that mass is infinite for the frame of reference regarding my question? Merged post follows: Consecutive posts mergedif we can really measure the relative velocity of 2 photons approaching each other whats the problem in supposing that light itself is the observer?
20. ## a problem regarding interference.

i didnt understand. pls explain. i am a 1st yr student in physics.
21. ## how can this happen?

if relative speed of light is constant for all reference frames- suppose there are two light sources one moving with a speed of light itself. now light emitted from them fall on a shooter simultaneously & gets reflected to a stationary observer now since the velocity of light was c wrt the person moving with the speed of light it must be 2c wrt the stationary 1. if not the stationary observer can calculate the vel of light as 0 for the source moves with velocity c itself. again if the vel is 2c for him he can observe the same event the shooter firing twice. for one of the lights travel f
22. ## what do you observe?

we suppose some events are occuring outside a reference frame which is moving with speed of light. what will the person inside the frame observe? everything occuring simultaneously or nothing occuring? both cases relate to 0 time interval. pls reply.
23. ## how was speed of light measured?

let us suppose there are two particles travelling with speed of light toward each other. now one cant see the other till they collide. say there is a mirror behind the 1st 1 at a distance d from the pt of their meeting in a stationary reference frame. can the 1st 1 see the 2nd reflecting back to it & then measure the relative vel? bt that cant also be possible for in the reference frame of the 1st d=0 & time taken by the 2nd particle to move the distance 2d is also 0. how do we know the relative speed?
24. ## black hole mystery

can u suggest me the expression of singularity? isnt it where some of derivatives dont exist? pls explain.
25. ## a problem regarding interference.

why all books call photon a particle if its a wave? photons r actually passing through the slits, doesnt deflect. so y those r obstacles. pls explain.
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