There’s a web post from the Nature website going around entitled “Simulations back up theory that Universe is a hologram.” It’s an interesting concept, but suffice it to say, the universe is not a hologram, certainly not in the way people think of holograms. So what is this “holographic universe” thing?
It all has to do with string theory. Although there currently isn’t any experimental evidence to support string theory, and some evidence pointing against it, it still garners a great deal of attention because of its perceived theoretical potential. One of the theoretical challenges of string theory is that it requires all these higher dimensions, which makes it difficult to work with.
In 1993, Gerard t’Hooft proposed what is now known as the holographic principle, which argued that the information contained within a region of space can be determined by the information at the surface that contains it. Mathematically, the space can be represented as a hologram of the surface that contains it.
That idea is not as wild as it sounds. For example, suppose there is a road 10 miles long, and its is “contained” by a start line and a finish line. Suppose the speed limit on this road is 60 mph, and I want to determine if a car has been speeding. One way I could do this is to watch a car the whole length of the road, measuring its speed the whole time. But another way is to simply measure when a car crosses the start line and finish line. At a speed of 60 mph, a car travels a mile a minute, so if the time between start and finish is less than 10 minutes, I know the car was speeding.
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