Craig Callender is a philosopher of science at UC San Diego, who has written a lot about the nature of time, including a fun illustrated book. He’s more than a bit skeptical of the multiverse idea, and somewhat contrarian about the low-entropy nature of the early universe: he thinks it’s just a fact we should observe and accept (“nomological”), rather than a feature that cries out for a better explanation.
Here we’re having a chat on the recently launched Philosophy TV, sort of Bloggingheads for philosophers. Craig’s head obviously looms much larger than mine, so I had to use my wiles to bob and weave, intellectually speaking.
Callender and Carroll from Philosophy TV on Vimeo.
Pingback: Tweets that mention The Arrow of Time and the Multiverse on Philosophy TV | Cosmic Variance | Discover Magazine -- Topsy.com
I tried to listen to this, hoping against hope that Callendar would eventually get around to saying something, but I just couldn’t stand it any more after 20 minutes or so. Can anyone direct me to a point in the recording where he actually has something substantive to say?
I would love to see you chat up John Carroll, a philosophy prof at NCSU. He taught a metaphysics course when I was there that dealt with metaphysical problems related to time travel.
Floating heads tv is more like it. Big and bigger floating heads.
I thoroughly enjoyed the discussion and although it was difficult to follow Prof. Callendar at times, his thoughtfulness was much appreciated. It was apparent that he carefully considered his words and the logic leading up to them.
If I understand correctly (big caveat here), I found two thoughts most interesting. That the so-called fine-tuning of the constants may not be so remarkable absent any real understanding of underlying principles and was somewhat perplexed at Sean’s statement that the mulitverse is not a theory but a prediction based upon the “hope” that one day the physical laws will be understood. Reaching on that one I think. Thanks again, good stuff.
I really enjoyed one side of the conversation. I got the impression that the philosophy prof was trying to avoid an overly technical discussion so let everything slide, but the video served me as a nice companion piece to Sean’s book.
The smallness of initial entropy is described by Sean as 1/10^(10^120).
Craig described a natural reduction in entropy as resulting from 6 dimensions in phase space reduced to 5, due to conservation of energy.
I wonder how these smallnesses compare? e.g. If some other condition reduced the phase space to 4 dimensions, would that change be larger or smaller than Sean’s factor?
I also pondered what Craig described,”phase space reduction”? It does open up some aspects of if Entropy is factored greatly by dimension number, the less dimensions the lower the Entropy, 2-Dimensional space is more Quantum than 3-Dimensional space when viewed from 4-D spacetime, thus it could be we are viewing Entropy in a dimensional backwards frame of ref?
There is also the factor of multi dimensionality, could have extra Entropic values (entropy shifts), based on actual dimension number, some extra dimensions will have entropy variations, because they are not standard 3-D, a simple Hydrogen Atom (3-D stable) will not exist in 5-Dimensional space, thus will not contribute to the keeping tidy of student rooms!..simplistically you do not need cleaners in extra dimensional space, entropy cannot function chaotically.
If students rooms had just 2 extra dimensions, then there would be more space to hide all the clutter, the 3-D room would look tidy, while the extra dimensions absorb the clutter!
A Thermal Fluctuation in 3-Dimensional space does not have equality in 5-Dimensional space.
Dear Sean,
who can seat and watch 2 heads talking for an hour, merci.
In 30 minutes, the most, anybody can communicate the point of his/her ideas. After that it gets tiring.