The most cited scientific support for the idea that consciousness creates reality comes from quantum mechanics — specifically from the observer effect. In quantum mechanics, a particle does not have a definite position or momentum until it is measured. Before measurement, it exists in a superposition of all possible states. The act of measurement — observation — collapses this superposition into a definite outcome.
This has been interpreted by some physicists and many spiritual teachers as evidence that consciousness literally creates physical reality — that without observers, there is no definite physical world. John Wheeler's "participatory anthropic principle" makes this claim at its most serious: the universe brought forth observers because observers are necessary to make the universe real.
However, the mainstream physics interpretation is more cautious. The "observer" in quantum mechanics does not require a conscious being — any physical interaction that records information about the system constitutes a "measurement." A detector, a photographic plate, a particle collision — all count as measurements in the quantum mechanical sense. The collapse of the wave function does not require a mind; it requires an irreversible physical interaction. The quantum observer effect is real and strange — but it does not straightforwardly establish that human consciousness creates physical reality.
What quantum mechanics does establish, more carefully, is that the physical world is not independent of observation in the classical sense — that there is no "view from nowhere," no God's-eye perspective on an independently existing reality that our observations merely track. The physical world and the observation of it are entangled in ways that classical physics never imagined. This is philosophically significant even if it does not directly support the strong claim that "I create my reality."