Recent content by Delzac

Is this for real? Sounds pretty impossible. http://www.wired.co.uk/news/archive/2012-03/09/230-percent-efficient-leds?p=2

Got it! Thanks. Was careless.

My bad edited.

Homework Statement An astronaut makes a round trip at 0.80 c to a star 20 light-years away, while her husband remains on Earth. Each sends the other a signal once a year by his or her own reckoning. Assume that the period of acceleration when the astronaut turns to head back home is small and...

Anomalies sometimes do surface. Or why not take it that you have done a wonderful work explaining the concept to me.^^

Okay thanks, got it.

Homework Statement Usually in physics problem on special relativity, the state that this particular spaceship is traveling at, say, 0.6c. Question is, where does this 0.6c come from? If the speedometer in the cockpit reads 0.6c, does it mean that the observer will look and think that it...

But, then how dose one use Inverse Lorentz Transform to get length contraction formula? Since t' is not the same, so we use the lorentz transform for t'?

Ah, i see. Thanks, got it.

Homework Statement From Lorentz Transform, x^{\prime} = \gamma (x - vt) From textbooks and wikipedia, L_0 = x'_2 - x'_1 = \gamma (x_2 - x_1 ) Where x_1 and x_2 = L Thus, \L_0 = \gamma L Question is this: If i take the same method and us the Inverse Lorentz transform, i seem to...

Oh, got it. Thanks eczeno. It was mentioned in the previous post, but the subtlety was lost to me.

So now we make it an infinitely long solenoid, an ideal perfect solenoid. The situation will still be the same. There is no magnetic field outside the solenoid, but the wire loop some how knows that there is a flux going through it. Why is this so?

In this case, we take an ideal solenoid, infinitely long. In this case, there should be zero, not even small, magnetic field outside the solenoid. If we were to put a compass immediately outside the solenoid, it would not be deflected. How then can the wire loop know that there is a changing...

Homework Statement I understand that if we have a solenoid with AC current running through it, it will create a changing magnetic flux. Suppose now we place the solenoid in the centre of the a single loop wire, according to faraday's law of induction, that single loop wire will have a...

I understand that there will be a force generated to brake the plate. But, from the picture, based on the circular pattern in the current flow, wouldn' there be a magnetic field generated. So, base on the right hand corkscrew rule, the pole on the top is north and the bottom part is south, thus...