0
votes
1answer
55 views

Scanning Electron Microscopy: Explanation of Numerical aperture and Extraction Field

I am trying to understand what numerical aperture and extraction field means in a scanning electron microscope. From what I understand numerical aperture is used to set the Depth of Focus which is ...
0
votes
0answers
320 views

holographic projection in thin air?

from where I come from ,they taught us in high school that it is possible to project holograms in thin air simply by illuminating the hologram with the "correct light" , and having a semi transparent ...
14
votes
3answers
196 views

Why and how will we be able to image extraterrestrial planets in the next two decades?

According to a recently published article, a well-established Cambridge astrophysicist stated that: the “origin of life, where it exists, and whether aliens exist, is going to be crucial over ...