What is an Observer? A Panel with James Hartle, Susanne Still, David Wallace, and Alan Guth

A panel discussion at FQXi's 5th International Conference with James Hartle, Adrian Kent, Susanne Still, David Wolpert, David Wallace, Alan Guth, and Adam Brown.

[jacobvandijk]

IF SEVEN physicists MUCH DISCUSS A TOPIC LIKE THIS THAN YOU KNOW HOW FAR WE HAVE SUNK IN physics!

[username-izel]

Man I love Alan's face at 30:00 I can't tell if he's thinking "wtf?" Or "this so much fun!" 😆

[Frohicky]

Q: Give a definition in two sentences
A: My answer will be in three parts. I'll start with some introductory remarks, lay out the argument, and then add some caveats at the end.

[SandipChitale]

(Macroscopic) Conscious entities are Observers not because they are conscious, but because macroscopic.

[saskueify]

its really funny that a bunch of bonified, smart, paid observers struggle to define their very nature. Unless they want an alien life form to some day treat them as if their experience is not real, they should start to consider this not so philosophical question.

[ErnestoEduardoDobarganes]

Listening now, but it seems weird to me that the universe would need a minimum of 3 elements to generate viable interactions : object 1 + object 2 + observer ?

[username-izel]

The volcano is just following a path from geology it didn't take a direction change then come back and say let's build a vent right here. It happens because it just happens to be the easiest way for the pressure to be released.

[cubefox]

Possible definition:
Being an observer := being conscious

[blitherbox]

Everything you can observe has already happened.  That's how flip books work.

[david_porthouse]

An observer is normally any entity heavier than the Planck mass for which the Heisenberg Uncertainty Principle can be replaced by classical Brownian motion on the same scale. Extraordinarily, an observer is a chain reaction like that induced by an alpha particle in nitrogen tri-iodide for which tachyonic Brownian motion does the job of collapsing the wave function. 2 sentences.

[Grrrnthumb]

I was a little disappointed they approached so many of the questions in a cowardly way, blathering on and hedging their bets without saying much. I was *very* disappointed at the plethora of "I think blah, blah..." compared to the dearth of facts. I really wish they had answered every question with "this experiment gave this relevant result" or disagreed about how to interpret specific experiments; not so much tedious esoteric opinions which obviously don't have enough experimentation behind them to have much relevance yet.

[saskueify]

in order to define observation you must be able to observe observation, as both a 3rd person and a 1st person experience. I wonder if its possible to Fully observe observation and if so, what context could possible sum it up?

[zero]

The measure problem strikes me as odd. You don't need to measure probabilities for the entire universe/multiverse throughout all time. If you select a finite inflationary patch at a specific time that you define as t=0, you can take a finite measure of the space that patch has expanded into within a finite time. As you expand that time forward, I imagine that most measures would approach specific values depending on specific parameters selected as t increases (in other words, there's a limit as t approaches infinity). This doesn't mean that you have a measure at infinity, but it does mean that you can make a prediction for any finite region, continuous region in a finite, continuous timeframe. Do you actually need more than that?

[schmetterling]

The concept of observer has never produced a single scientific result. It can be safely sent back to the philosophy department, where it came from.