Rovelli: "Reality is interaction" we understand the world better not thru how things are but how things interact with other things. Like a kiss
The permanence of things is dependent on the time horizon we are comfortable with.

Pointer from: FT article on entropy >> Learning about Carlo Rovelli >> Always a good match on On Being
Place digested: Driving with Hardy
Time digested: May 20, 2018

Related: rovelli science is process of discovery on being. New addition: some beautiful things can be wrong
  • "Reality is interaction" we understand the world better not thru how things are but how things interact with other things. Like a kiss
  • Permanence of things is dependent on the time horizon we are comfortable with. For stone in our spacetime seems like a thing but over a billion years could be happenstance

For rovelli can have different perspectives of time. Eg spacetime vs emotion of time and human understanding of life (eg Einstein as getting older / upon friends death) talking about time

[ME] A stock is a history of changes (a la D Meadows). What is the stock of kisses (ie ephemeral happenings?) How does this relate to the emotion we feel towards others?

Stable subsystems is how learn and be understand. Work to stabilize subsystems so can build on top.

MN: I can't distinguish between what I do and art

The higher you go the faster time pasts
Up and down makes sense on Earth but not in space

When description team and no heat cannot determine past and present
Only when heat around the direction of time exists
Direction of time deals with presence of heat
What is heat, molecules moving fast
Microstructure we don't see
We talk about heat bc simplication in world as we perceive it

Heat is clear that link is time
But How come time energrs when degrees of freedom not under our control

straddle physics and philosophy

Here and now always subjective

Physics struggles to give objective perspective (as much as possible) but look from outside miss perspective of inside

Words like here and me that have meaning depends on who says it

Aspect of reality connected to relational aspect. Perceive from inside. Difference between all of us.

Top layers hold the importance. Focus on the top layer. Ends up with the importance (for good and bad) et epicenter plaque

Memory palace: friction of the brain process new places extra heat time holds more importance


MS. TIPPETT: Right, so you’ve said somewhere — you wrote, "The passage of time is internal to the world, is born in the world itself." So here’s one very intriguing thing you say — again, as a physicist — to the question of what explains that, for us, time seems to pass, or to "flow." And you say, you believe this is connected to the "connection between time and heat" — that the "difference between past and future exists only when there is heat." That is such a baffling and fascinating idea. Can you just explain that a little bit?

MR. ROVELLI: Oh, yes. Oh, this is something that, curiously, has not been said enough, and the known physicists don’t know it; but it’s not something new, and it’s something well-established. In fact, since not the last century but the previous century, every time we give a description of the world, of phenomena where there is no heat, we cannot distinguish the past from the future. Every time there is something that distinguishes the past from the future, there is heat.

So take a movie or something, and you run it backward. Imagine you take a movie of the moon going around the earth. You run it backwards, and you see a moon going around the earth the other way. It’s completely consistent with the laws of physics, and there’s no heat there. But if you throw a pen on the table, and it stops, and you take a movie of that, if you run the movie backward, you see something totally absurd — a pen that starts moving from nothing; and in fact, when the pen stops, it heats the table because there’s friction, and there is heat. So only when there is some heat around, the phenomena are different in one direction of time from the other. So the direction of time is deeply connected to the existence of heat. That doesn’t explain the direction of time but is a first step toward understanding it. The direction of time has to do with the presence of heat.

MS. TIPPETT: Is there a way that we experience this unconsciously in our daily interactions or our sense of time? Or is that just a separate experience?

MR. ROVELLI: I think our own experience of the world — our thinking, our being, our emotions — are so much produced by our brain, our body, which are full of heat, [laughs] a deeply thermodynamical thing, so we cannot get out from this presence of heat when we think about our experience. When you think, your brain produces heat. When you wake up in the morning, your body produces heat. When you have an emotion, there is heat producing. And so we, in our experience, are children of the presence of heat in the world. I think that in a world completely without heat, we wouldn’t make sense. We wouldn’t be able to think. We wouldn’t have memory. Memory requires heat.

MS. TIPPETT: So because there’s so much heat in us and that we generate all the time — time — [laughs] all the time — time seems to be this dynamic, rapid —I think we experience time as a bully for much of our lives; at least, the way we live now. [laughs]

MR. ROVELLI: Yes, there’s something we did understand about heat, a little bit after having understood this relationship between heat and time. We see that has to do with the microstructure of space; and that what is heat? Heat is the fact that there are many molecules, moving fast. So the second step is to understand that heat has to do with the fact that there is a microstructure we don’t see. A hot glass of water is a glass of water where the molecules move very fast, a cold glass of water is the same glass of water where the molecules don’t move much. But we don’t see the individual molecules. So we talk about heat, because there is a sort of defocusing. There’s a big simplification in the world as we perceive it. There is a coarse graining —

MS. TIPPETT: As we perceive it.

MR. ROVELLI: As we perceive it; exactly. And that’s one of the things, I think, we should understand better and we haven't, yet, understood well. So the relationship between time and heat is clear, but the next step, which is, how come time, in some sense, emerges when there are many, many degrees of freedom which are not under control? That’s something we should understand better. It’s one of the mysteries of the — against which physics is striving right now, I think.