Recent content by cronnin

So what happens with orbital and spin magnetic moment? How does iron stay magnetic if all valence electrons roam free without unified momentum?

Theory explains magnetism in iron as a combined effect of magnetic moments of electrons. Now, what is confusing me is that valence electrons in iron are supposed to be free. The valence band and conduction band overlap. So, what kind of orbital and spin-ular momentum do these free electrons...

Yes, that was also my mistake in thinking. It seemed for a moment that 2D owl (from the first post ) would get compressed into a single point, but that's not the case since a whole owl cannot fit in there. Thanks for all the input ppl. It's all much clearer now.

It was just me, thinking loud, and I agree that my comment was a bit redundant. I'm trying to understand magnification and how projector lens zooms the picture on the wall, and I first had to be sure about what seems trivial for the rest of you :) so that I could read further about it. Oh, so...

At the moment I think I'm having a problem understanding what this actually means? Are the images at 5:00 and 5:20 cases of focusing object at infinite distance or not?

1. Let's put a lens beside the white wall and fix the distance to be same as the lens' focal distance . If we turn on a huge LCD screen at large distance, it should form a sharp image on the wall? The rays coming from infinity should converge at focal distance? 2. If we move LCD closer to the...

Yes, the focal plane should be where parallel rays converge into point. The distance between the lens and that plane should be the focal distance? Why won't it form an image? If it focuses to infinity it must form some kind of image somewhere on the right side? That's the only thing we ever...

I've made a drawing of what is confusing me here. 1. This should be a case of focusing into infinity or not? 2. Can anyone explain what happens with the owl?

My problem was/is with keeping synchronized clocks in sync when you're moving them. For example (just one of the many), you and I synchronize clocks in Florida, and then go same distance but different speed. You go Concord to France, and I go same distance to Africa but in an ordinary airplane...

Ok, now we're getting somewhere :) But does this mean that you can never get synchronized clocks, because they go "desynced" as soon as you move some of them to different location? Or at least, if you want them to be in sync, you should calculate the dilation, and calculate it in before...

Oh, this is getting cumbersome, writing one thing on paper, different in Word, and third in here :) Brother's time dilation factor is 5/3, which means that he'll see our 12.5 years as 7.5 years. Sister's time dilation factor is 1.0911, which means that he'll see our 25 years as 22.91 years. So...

Oh, sorry, my mistake. So, they should cover the distance of 10 light years. It was pretty much stupid of me to say that they travel slower than light and are there years before the light is :) Brother is traveling at 80% speed of light, and he'll do it in 12.5 Earth's years. Sister is...

Yes I know that, but where does it get them time wise. At first all triplets are stationary and synchronized. Then the two start accelerating compared to Earthling, but not to one another. Then the second one stops accelerating, which leaves only the third one accelerating for some time. Then...

I'm assuming they are both accelerating when they start from Earth, and decelerating when they arrive on asteroid. It's more like a triplets problem, where one stays on Earth, and second and third are traveling but with different speeds. I'm assuming that the (Earth - first triplet - asteroid)...

OK, twins start from Earth, and go to the asteroid 10 LY away. Brother is traveling at 80% speed of light and sister is traveling at 40% speed of light. gamma(brother) = 5/3 gamma(sister) = 1.0911 So, they will be arriving on asteroid after: t(brother) = 6 years t(sister) = 9.165 of their...