3 ms·

So, the wave of light is actually 3d? then if it is 3d, why don't we see the vertical bars in the interference pattern like this ? - - - -.

• abdullahkhalids 8y ago
  1. Yes, light is always 3D but the description in popular science is always simplified. Also experiments usually measure along a line across the screen and don't build up a 2D pattern on the screen that you usually see in popular science. For instance Fig 4. here [1] . 2. Because the light does not diffract up and down too much, only horizontally. So, for instance, the light emerging from the middle of the left slit stays at the middle level and does not interfere with the light emerging from the bottom of the right slit. Imagine looking somewhere on the screen at middle height where the path lengths are so that its a dark point. The light here is coming from the middle of both slits. Now move down a bit. The light here is coming from the bottom of the two slits here, and the path lengths are still the same. So you still get a dark point. I hope this makes it clear. [1] http://elib.bsu.by/bitstream/123456789/154548/1/1991-066%20PRL%20Carnal%20%26%20Mlynek%20-%20Young%E2%80%99s%20double-slit%20experiment%20with%20atoms%20-%20a%20simple%20atom%20interferometer.pdf http://elib.bsu.by/bitstream/123456789/154548/1/1991-066%20P...