Identity and philosophy · experts disagree
The teleporter problem
Derek Parfit, Reasons and Persons (1984), building on earlier fission cases by David Wiggins and others.
A teleporter scans your body and brain down to the last atom, destroys the original, and sends the pattern to Mars, where a machine builds an exact copy from local matter. The person who steps out on Mars has your memories, your plans and your character, and feels like you. Most people, after some thought, say they would use it. Now the machine is upgraded. It still scans you and sends the pattern to Mars, but the new scanner no longer destroys the original. You step out of the booth on Earth, feeling fine, and are told that your copy is already walking around on Mars, and that the scan has damaged your heart: you will die within a week. The copy will carry on with your life.
Should you regard this as roughly as good as ordinary survival, since someone with your psychology continues, or as your death?