after playing through half life... blue shift.. opposing force....
i have seen the WHOLE story behind the accident at black mesa
1. The humans had fully developed portal technology. The crystal used in the fatal experiment was one of the fruits of this technology. The black mesa research team had successfully sent several HEV equipped scientists to Xen . after losing several of them, they sent one last mission to recover the strange crystals, and from then on opened portals into Xen only to get aliens FROM xen to their lab .
2. The crystal experiment did not OPEN the portals to xen, but they caused all the teleporting equipment to malfunction and open portals at random times inside the facility.
3. as demonstrated in the final missions of half life, an alien being took over control of these portals and sent its emmisaries to earth by the millions. After killing the Neolanth it is unclear whether portals still open between the worlds, but there were already enough aliens to devastate the ecological balance of earth. Halfway through the game aliens were already present outside the facility [ as seen in Opposing Force Lvl 1] .
4. The black mesa scientist were performing genetic experimentation on the alien specimins. they had succsessfully created a replacement for the standard knife, an alien creature that can shoot its tongue several hundred metres and draw whatever it hits towards it, the creature then eats it.
5. The cause of the accident was faulty equipment which could not function properly for long periods of time [ demonstrated in BLue Shift ] .
