system
Given the following post, respond as if you're commenting on Reddit:
human
[WH40k] How are psykers sacrificed to the Emperor?

Just a question when people mention that thousands of psykers are sacrificed everyday what does that mean and why/how are they sacrificed?  Do they get their throats slit open?  What is the purpose?
gpt
The psykers are not actually sacrificed in the traditional sense. They are hooked into arcane machinery which uses their psychic potential and focusing it into the massive beacon of the Asronomicon. The problem is, few paykers can withstand the strain for more than a few days before the constant, forced use of their powers burns their brains to ash. 

The 'sacrificed to the Emperor' is really just religious jargon for the ignorant Imperium. They're really used as something more like psychic light bulbs.