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  • Marcus Huber: Time and time again

Marcus Huber is Associate Professor at the Technical University of Vienna, and group leader at the Institute for Quantum Optics and Quantum Information (IQOQI), which is part of the Austrian Academy of Sciences (ÖAW). He studied at the University of Vienna and gained professional experience at the University of Geneva, the Universitat Autonoma de Barcelona and the University of Bristol.

Keywords: IAF Information Fuel TWCF, IAF 2019, Huber

Good video! My comments are:

  1. I don't understand why it's thought that just because you can reverse the sign of the time variable in mathematical equations that this means that time can be reversed in the actual physical universe.

  2. From my layperson's view time is not fundamental. It's just a function of physical things happening (e.g., physical change). If there were absolutely no physical change in the universe, there would be no time. This explains why time is moving irreversibly from past to future: because things keep happening. To go from future to past, there would have to be a reduction in the number of things, or events, that have already happened in the universe. This doesn't occur. Even if the events of a process look like they're happening in reverse, like if a broken cup spontaneously reassembles, this doesn't mean that time is going backwards; it just means that additional physical events have happened that reassemble the cup and that happen to look like the previous events. But because physical change is still happening as the cup is reassembled, and the number of events is still increasing, time is still moving forward.

  3. If time is related to entropy or the amount of disorder in a system and because entropy increases in the universe as a whole with time, physicists wonder why there would be very low entropy (disorder) at the beginning of the universe. This makes sense to me, though, because if the universe started from a single existent entity which then proliferated to produce our current universe, there would have been initially a very low amount of disorder. Additionally, if time is based on physical change, or events happening, in this model, time would start with 0 and move constantly forward as the number of physical changes in these entities, or events happening, increases in the universe.

  4. I think a good way of visualizing entropy at the macro level is to imagine a bunch of oxygen atoms in the corner of a box containing no other atoms. As the oxygens bounce around, they'll push against each other and cause the atoms to move throughout the box. There aren't any atoms outside the original bunch of oxygens, so there's no bouncing around coming from the outside to keep the oxygens as a bunch.

5 days later
  1. Agree
  2. The movement of time, common to all physical changes, must be the basis for all physical things and changes.
  3. Time cannot start from zero. For the movement of time to begin, time must already be.
  4. Poor rendering - the box creates a border.
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