Though he never made a major scientific discovery or set foot on the moon, few people expanded the universe the way radio host Art Bell did.

Bell, who died at age 72 on Friday (the 13th, no less), helped make the paranormal accessible — and acceptable — for millions with his nationally syndicated radio show “Coast to Coast AM” beginning in 1988, years before “The X-Files” or the countless ghost-hunting pseudo-reality series brought it to the forefront of pop culture. 

Bell’s favorite topics included conspiracy theories, hauntings and alien abductions with stories so bizarre and captivating they kept many a…