The technique you're looking for is called Candling. I used to do this when I made the flu vaccine.
Its basically a light with a rubber cup on it to focus the light into the egg. Works really well.
Here's a random website that seems to have good info:
I was there! It was pretty great actually. Hemispheres was incredible and the crowd really popped for YYZ. Overall very well done, and some very impressive skills on show.
Yes! I'm on my ~20th play though I reckon. I get to the end and go straight back to the start.