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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

#111

Post by jandrewrogers »

paulusthe wrote: post #38
marcus_holmes wrote: post #37

Interesting because it messes with the school of thought that everything is determined already and we're just following a sequence of actions that arise from the starting conditions of the universe. If causality is broken then maybe we have free will?

That's a very lazy school of thought though. It's just atheistic Calvinism, a tautology masquerading as a "philosophy". Calvin believed in pre-destination (your fate and every decision you make is decided before you exist) on the grounds that, because God exists and is omnipotent, what you are doing must therefore be what God wants to happen, both good and bad. After all, God is omnipotent, so there you go. Today's C…

I don't follow this argument. The coexistence of probability theory and strict determinism create no issues in modern mathematics.

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

#112

Post by icegreentea2 »

Apocryphon wrote: post #69
kwhitefoot wrote: post #18

Earlier quoted context omitted.

The block universe: https://plus.maths.org/content/what-block-time

Is it the same thing as the holographic universe theory that was in vogue a couple of decades ago? https://i.pinimg.com/originals/27/d7/8c/27d78c9c3ee93c13eda4...

No. The block universe is that 3+1D spacetime "exists all at once". We just happen to experience travelling through it in one way.

Holographic universe is that the physics and information in a 3+1D space time could be encoded into a 2+1D universe (with it's own physics).

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

#113

Post by entropicdrifter »

nanidin wrote: post #103
whatshisface wrote: post #85

Earlier quoted context omitted.

It is because in both cases, you can work out that you'll never make an observation that really proves it one way or the other, but you might come up with some laws of physics that are more conveniently expressed in one way than another. They're both ultimately questions about your coordinate system, and in fact it is easier to invert time than it is to work out how everything's supposed to function in a rotating+sun…

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.

Gravity is a universal constant. If you reverse time, you just reverse the order of cause and effect, not what the effect is.

Does that make more sense to you?

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

#114

Post by whatshisface »

sidlls wrote: post #108
whatshisface wrote: post #85

Earlier quoted context omitted.

It is because in both cases, you can work out that you'll never make an observation that really proves it one way or the other, but you might come up with some laws of physics that are more conveniently expressed in one way than another. They're both ultimately questions about your coordinate system, and in fact it is easier to invert time than it is to work out how everything's supposed to function in a rotating+sun…

It isn't because we have the observations we have. It might be mathematically easy to invert time, but empirically it's not so simple. Mathematical symmetries and expressions are nice, but then the actual physical consequences and requirements (e.g., material, time, energy inputs) sort of force one's hand. Also, geocentrism is actually disproven by numerous observations, which in fact guided the mathematical formulat…

>Also, geocentrism is actually disproven by numerous observations, which in fact guided the mathematical formulation of our current physics.

The validity of a coordinate system with the earth stationary at the center is guaranteed by the general principle of relativity. To get the stars to circle around it you would add a radially increasing potential in classical mechanics, or some coordinate shenanigans in GR. These coordinate systems are used in aerospace engineering to get convenient expressions of L1 points, etc.

I know it sounds hard to believe, but if you're willing to bite the bullet that "the center of the universe" has no physical meaning, then earth can't be not the center of the universe any more than it can be.

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

#115

Post by QuercusMax »

dietrichepp wrote: post #20
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…

I used to work at camp. You didn’t need to tell kids about fire; they could figure it out. Don’t touch the fire. Flashlights were too complicated. It’s night, a kid turns on their flashlight, points it in their eyes, says “ow” and can’t see where they’re walking until their eyes readjust. Flashlights are beyond our instinctual understanding of how the world works.

Maybe this is just because the kids had prior experience with fire (touch it = ouch), but no experience with flashlights?

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

#116

Post by weknowbetter »

seydor wrote: post #106
jonny_eh wrote: post #77

> It may seem eerie to our brains, which process events sequentially, but the history of science is also littered with examples of human biases leading to bad conclusions, such as the Earth-centric model of the solar system. Slow down. Assuming that time moves in one direction is not comparable to geocentrism.

Assuming that time "moves" kinda is

Nothing actually moves according to Zeno's paradox.

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

#117

Post by kridsdale1 »

7thaccount wrote: post #105
jonny_eh wrote: post #77

> It may seem eerie to our brains, which process events sequentially, but the history of science is also littered with examples of human biases leading to bad conclusions, such as the Earth-centric model of the solar system. Slow down. Assuming that time moves in one direction is not comparable to geocentrism.

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.

Scrambled eggs can become whole again by being consumed by insects, who are then consumed by chickens, who then lay eggs.

The biological processes enabling that sequence can be said to have negative entropy.

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

#118

Post by whatshisface »

nanidin wrote: post #103
whatshisface wrote: post #85

Earlier quoted context omitted.

It is because in both cases, you can work out that you'll never make an observation that really proves it one way or the other, but you might come up with some laws of physics that are more conveniently expressed in one way than another. They're both ultimately questions about your coordinate system, and in fact it is easier to invert time than it is to work out how everything's supposed to function in a rotating+sun…

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.

Let's check.

F = ma

F = m dv/dt

u = -t dv/dt = -dv/du

- F = m dv/du

If you stop there it looks like you're right, but you also must change the definition of velocity to account for the new time.

v = dx/dt = -dx/du

+F = m dx/du

So the direction of gravity (the force F) stays the same when you flip time. I can explain that without the math by pointing out that if you took a video of a ball being thrown up and caught and played it in reverse, it would still depict a ball being thrown up and caught.

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

#119

Post by kridsdale1 »

causality0 wrote: post #98
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…

The sun being classified as a yellow dwarf does not mean it's "only yellow hot". You can observe that by going outdoors and holding up a white piece of paper and noting it is not yellow in sunlight. powered by a nuclear explosion Not quite accurate. The nuclear fusion going on inside the sun's core is not an explosion. In a nuclear explosion, a significant fraction of the fuel in a given area is consumed in an instan…

The sun is the color it is because its surface is 5500 Kelvin, which we have defined as white. The sun is cooler than most visible stars, so it can be called yellow by comparison.
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