In 1993, the Dutch Nobel prize-winning physicist Gerard t’Hooft suggested that all the information in a region of space can be represented as a hologram, an idea that implies that the laws of physics that govern our universe are somehow encoded on its (higher dimensional) boundary.
This idea, known as the holographic principle, has a certain elegance and so has received widespread attention from some theorists although nobody knowns whether it is a true description of the universe or not.
If it is true, Jae-Weon Lee from the Korea Institute for Advanced Study in Seoul and some pals, say that this boundary should emit Hawking radiation.
Hawking originally dreamt up this radiation idea to describe a process that might occur near the event horizon of a black hole. When pairs of virtual particles pop into existence (as they do all over the universe), they normally annihilate each other and disappear again. But near a black hole, one of these particles can cross the event horizon while the other makes its escape and this gives the impression that the black hole is emiting radiation.
Lee’s team say a similar thing may happen at the holographic boundary and that the energy this creates might be responsible for making the expansion of the universe accelerate.
They also explain why this radiation does not interact with ordinary matter and so is not seen in other ways: it’s wavelength, being universe-sized, is too long.
Seems as good an explanation as any other at this stage, after all the competition is ideas like quintessence, k-essence and quintoms.
Two things though: if this radiation exerts a force, why would it act to accelerate the expansion of the universe and not decelerate it? Lee and co are not convincing on this point. And, I wonder whether t’Hooft, who has some exotic ideas of his own about quantum determinism, would say that this kind of cosmic Hawking radiation is not compatible with the holographic principle and therefore bunkum.
Ref: arxiv.org/abs/0803.1987: Is Dark Energy from Cosmic Hawking radiation?
Oooh, you *almost* spelled his name right. It’s
‘t Hooft
And while we’re nitpicking: “say that this boundary should [emit?] Hawking radiation.”
best,
Bruno van Wayenburg
‘t Hanks
The Cosmic Microwave Background (CMB) has the temperature 3 K, which roughly corresponds the temperature of Hawking radiation of tiny black hole, whose lifetime is about 150+GYears, i.e. the life time predicted for our generation of Universe. This can serve as an indicia, the CMB is the Hawking radiation of our universe, which is evaporating itself by increasing speed like common black hole. This behavior can be perceived as an increasing of the Universe expansion from inside perspective – from this the dark energy phenomena follows.
The holographic principle is not just about the laws of physics being encoded on a boundary surface (not a higher dimensional space – a lower dimensional one) but about all physics, meaning all events, actually happening there, and not in the three dimensional arena we think of as reality. If the boundary surface emits Hawking radiation it must be an event horizon. That means, according to Special Relativity, no information can be received here from there. It follows that no physics, or information about events, from there can be known here. It is a self-defeating hypothesis.
Neil, there is a flaw in your argument. Hawking radiation is a phenomenon that results from the splitting of pairs of virtual particles. Thus, if we can observe particles on our side we can deduce what particles are on the other side. The information of what the particles are on the other side does not pass through to our Universe but from the information we do obtain we can get useful (?) results. I believe that to be a moot point myself. The holographic boundary would encode information of time and position of particles in our Universe but on the other side of the boundary, the physics must be different, else it wouldn’t be the boundary. This might entirely preclude the posibility of Hawking radiation, after all, who says that our Universe is going to exert a gravitational pull on things outside of it? Let’s assume that there is Hawking radiation. When it crosses the boundary, it has to become information encoded as position and time but what combination thereof? I see no reason that it must become a particle that fits in our Standard Model. Maybe all we get is a gravity wave.
Seems needlessly complicated. Occam’s razor would shave this one off.