Re: Dark matter/energy question
"Is there a reason there can't be multiple experimental facilities at multiple locations?"
Provided the money can be found, none what so ever - on the other hand, finding enough suitably qualified people to staff them all and run them in a productive manner might be a different story.
I suspect that having all the people of different nationalities working with this sort of technology in one place also puts a brake on any thoughts regarding the potential of weaponizing it - such thoughts come easier to individual governments when the facilities and staff are all in-country and under their control.