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A growing number of scientists are convinced the future influences the past

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Re: A growing number of scientists are convinced the future influences the past

#371

Post by pixl97 »

theemathas wrote: post #121
nanidin wrote: post #103

Earlier quoted context omitted.

If we reverse time and this implies running everything backwards in physics, do we include gravity in the set of things that are reversed? Then everything would fly off the face of the earth in reverse-time.

Reversing time on an attracting force still gives you an attractive force. Velocity is reversed, but acceleration isn't. Imagine a ball being thrown up and then falling down, in a parabola. Reversing a video of that still gives you a video of a ball in a normal parabola trajectory.

The history of the universe channel on YouTube has an episode called 'what is time' that goes over symmetries like this. Lots of atomic/quantum scale interactions are time reversible like this, but not quote all, and that may be where time arrives from.

Well worth watching that episode as it does far better explaining than I do.

Re: A growing number of scientists are convinced the future influences the past

#372

Post by pyinstallwoes »

wisty wrote: post #3

Human instincts only apply to the systems that they're "evolved" to handle (or the systems we can readily observe and learn from). Think about big systems. The moon is a ginormous rock that's so big it is visible from thousands of km away, but it just hangs in the sky because it's moving so fast it can cheat gravity, but we can barely even see it move. Or think about how a star can somehow explode because it starts r…

Perhaps our gut is right and our conceptual models are wrong

Re: A growing number of scientists are convinced the future influences the past

#373

Post by lupire »

TechBro8615 wrote: post #193
a257 wrote: post #173

Earlier quoted context omitted.

Please elaborate.

I'm neither a mathematician nor a physicist, so I'm not nearly informed enough to elaborate on the subject properly, but I would note that the axiom of choice is not proven, and while you can mathematically divide a continuum into infinitesimally small sets, you cannot do the same to physical matter. From my understanding, many of the contradictions between classical and quantum physics arise at this boundary between…

This whole thread hinges on your not giving credence to the word "practically" , as in "approximately". No countably infinity needed, and Continuum Hypothesis isn't relevant at all in any way, as it is aboit uncountable infinity. Until you explain what you are trying to say, you aren't saying anything meaningful. The one showing hubris here is you, tossing around technical terms don't admit you don't understand.

Re: A growing number of scientists are convinced the future influences the past

#374

Post by MattPalmer1086 »

resource0x wrote: post #169
7thaccount wrote: post #105

Earlier quoted context omitted.

Yep. Someone else already pointed out the well known counterargument to symmetry below regarding thermodynamics. You typically don't see scrambled eggs become whole again. I think that's pretty hard evidence to overcome. Granted, I'm not a physicist and I'm sure any physicist working on this totally understands that. Just wanted to point it out.

If the direction of time is reversed, the eggs become whole again, but your memory of them once being scrambled is reversed, too, so you don't notice anything unusual. (It's like a rollback of database transaction, where not only the database state, but also the state of everything, including your brain, is getting rolled back)

So the conscious experience of the person at each time would be exactly the same as our experience. They would feel as if they were moving forward in time.

Re: A growing number of scientists are convinced the future influences the past

#376

Post by lupire »

dekhn wrote: post #198
a257 wrote: post #168

Earlier quoted context omitted.

A probability of zero does not mean that the event is impossible. When we refer to probabilities we are talking about probability densities. Infinite precision is a useful modeling tool in the same way that approximations of pi are useful.

In a well defined system, a probabiltiy of zero by definition means an event is impossible.

In physics, nothing can be measured exactly, so exact events are in fact impossible. Measurements are approximate, and thus have finite extent, and thus can have nonzero probability.

This whole thread is silly, The 2nd law is about probabilities which are asymptotically 0, so small in practice that we could never do experiments to frequentist probability empirically, using "jars of marbles" with more than 100 marbles", let alone trillions of trillions of particles.

Re: A growing number of scientists are convinced the future influences the past

#377

Post by lupire »

PartiallyTyped wrote: post #182
a257 wrote: post #168

Earlier quoted context omitted.

A probability of zero does not mean that the event is impossible. When we refer to probabilities we are talking about probability densities. Infinite precision is a useful modeling tool in the same way that approximations of pi are useful.

I think I was misunderstood. My comment regarding infinite precision was mostly aiming to argue that any single point has probability zero but an event still occurs. This was then used again when mentioning earth to argue that depending on the definition of "order" here: > And no practical amount of shaking the jar will ever return the marbles to a high order state again. It is entirely possible to reach a state of h…

Define "large", at least in an estimate. Dividing two astronomically large numbers is not easily estimated. And define "entirely possible". Yes, could happen once, maybe, in the entire Universe is entirely possible. Anything is "entirely possible" because humans are not omniscient, so we have to start from Bayesian priors.

Re: A growing number of scientists are convinced the future influences the past

#378

Post by lupire »

RajT88 wrote: post #126
__MatrixMan__ wrote: post #84

Earlier quoted context omitted.

I think of personal growth as a conspiracy between present me, past me, and future me. Where our motives are aligned, good things happen.

Past me leaves future me notes. I often find them insightful, especially if I am reviewing them again years later.

The reverse is the more interesting part. Roko's Baslisk loves you and wants you to be happy, and wants you to create him.

Re: A growing number of scientists are convinced the future influences the past

#379

Post by lupire »

gpuhacker wrote: post #93
theGnuMe wrote: post #61

Earlier quoted context omitted.

I like this concept. Is there any sci-fi based on this premise?

Surely reminds me of Harry Potter and the Prisoner of Azkaban, where Harry is saved by himself as he at some point in the future travels back in time to save himself.

Bill and Ted's Excellent Adventure, but yeah.

Re: A growing number of scientists are convinced the future influences the past

#380

Post by lupire »

taskforcegemini wrote: post #160
pif wrote: post #48

> A growing number of scientists... Beware, getting from one to two is already a growing number!

that's actually a big jump, 100% increase

It's growing exponentially, perhaps even factorially.
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