>>211916495What doesn’t make sense about it? Imagine there’s only one timeline. At some point, time travel gets invented, and the person who invented It decides to go back 10 years. The simple act of going back 10 years creates a new timeline branch. Everything in the past is the same as the first timeline, but everything going forward is subject to change. The original time line continues to exist and move along without the person who travelled back in time. Why would it suddenly collapse? It would just exist without them as if they died. If they then decided they wanted to go back to the future, they wouldn’t return to their old timeline. They’re no longer part of it. instead they would jump to a future date in their current timeline, as if they’d frozen themselves in an iceberg and remerged years later. If while travelling forward through time, other people engaged in time travel, then they too would create new timeline branches. If someone wanted to go back to their original timeline, then they’d have to jump between dimensions as opposed to time travel. Each timeline is free to have there own ‘present’ as well. The logic is sound if you think about it carefully.