It’s still possible we all live inside a hologram

Credit: TU Wien

Credit: TU Wien

Jamie Lendino via ExtremeTech:

Mathematicians are already familiar with the holographic principle, which the famous physicist Leonard Susskind first proposed. It asserts that a volume of space can be thought of as encoded on a boundary to it — such as an observer-dependent gravitational horizon — and therefore needs one less dimension then it appears to need. By extension, since our universe seems three-dimensional to us, it could actually be a two-dimensional structure that’s overlaid onto an incredibly large cosmic horizon.

Back in 1997, Juan Maldacena first postulated the theory of a holographic universe, saying that gravity arises from thin, vibrating strings that exist in 10 dimensions. Other physicists have been working with the concept since.

“The work culminated in the last decade, and it suggests, remarkably, that all we experience is nothing but a holographic projection of processes taking place on some distant surface that surrounds us,” wrote physicist Brian Greene, from Columbia University, in 2011. “You can pinch yourself, and what you feel will be real, but it mirrors a parallel process taking place in a different, distant reality.”

Now physicists at TU Wien (Vienna) are proposing that the holographic principle works even in a flat spacetime, and not just in theoretical regions with negative curvature. As a general rule, gravitational phenomena are described with three spatial dimensions, while quantum particles are described with just two dimensions. It turns out that you can map the results of one onto the other–a stunning finding that has led to over 10,000 scientific papers in theoretical physics on negatively curved spaces thus far. But it hasn’t seemed at all related to our own, flat, positively curved universe until now.

Read the entire article here.