Up Next
Back to Show
PBS Space Time
Why Do You Remember The Past But Not The Future?
Season 7
Episode 1
The laws of physics don’t specify an arrow of time - they don’t distinguish the past from the future. The equations we use to describe how things evolve forward in time also perfectly describe their evolution backwards in time. Why does the brain and the conscious experience that emerges from it, see the arrow of time so clearly? In other words why do we remember the past and not the future?
Support Provided By
14:42
Gödel found a time-travel solution in General Relativity, revealing spacetime can loop on itself.
18:46
Tardigrades can survive almost anything—even most of Mars. But one Martian chemical stops even them.
18:18
The Higgs boson may open a portal to hidden particles that could explain dark matter.
19:02
The universe expands faster. “Dark energy” may not be constant after all.
16:26
There’s a new generation of experiments that may unlock the gravity particle.
18:33
The universe thrums with quantum fields, except something may be missing: the sterile neutrino.
18:42
Gravitons, the particle of quantum gravity, may be impossible to detect.
25:02
2025 was the international year of quantum science, but today we examine its origins.
21:17
We’ve found lots of “habitable” worlds but we don’t know what factors are needed for life.
19:52
Antimatter drives sound like science fiction, but they may not be as far as you think.
23:22
Does quantum mechanics allow the future to retroactively influence the past or not?