The chronology protection conjecture might prevent time travel effects.

Evidence

This says that the laws of physics conspire to prevent macroscopic bodies from carrying information into the past. — Hawking, Stephen, A Brief History of Time, 305

Categorization

• corroborated: 2 independent passages support this claim — Hawking, Stephen, A Brief History of Time, 305
• XREF: connects to: Classical laws previously ruled out any time travel possibility. — Hawking, Stephen, A Brief History of Time, 290; Forgotten chart pop can function as time-travel triggers into a past era — Mark Fisher (edited by Darren Ambrose), K-Punk: The Collected and Unpublished…, 223

Related

• Classical laws previously ruled out any time travel possibility. (similarity 0.87)