Today's post, Timeless Beauty was originally published on 28 May 2008. A summary (taken from the LW wiki):

 

To get rid of time you must reduce it to nontime. In timeless physics, everything that exists is perfectly global or perfectly local. The laws of physics are perfectly global; the configuration space is perfectly local. Every fundamentally existent ontological entity has a unique identity and a unique value. This beauty makes ugly theories much more visibly ugly; a collapse postulate becomes a visible scar on the perfection.


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This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Timeless Physics, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.

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4 comments, sorted by Click to highlight new comments since: Today at 1:04 PM

Namely, I have no problem with discarding time and keeping causality.

Why would you? If you have time, the universe has laws and a boundary condition at t = 0. Causality arises from this. If you don't have time, the universe has laws and a boundary condition at configuration = big bang. Why wouldn't causality arise from this?

I have never been good at math and a high percentage of content discussed here is over my head. However, I am hoping this does not exclude me from a sincere attempt to grasp the general concepts and discuss them as best I can. In other words, I'm hoping my enthusiasm makes up in some way for my total ignorance.

My take on this is that, within a mathematical equation, if a specific variable does not have a discernible impact on the resulting value, it is irrelevant to the equation. Such a variable may exist merely as a conceptual "comfort" to the human method of perceiving the universe, but that doesn't mean it serves any meaningful/rational purpose within the equation. If pure rationality is the ideal, then all "truths" should be reduced to their absolute smallest value. In other words, trim the fat no matter how damn tasty it is.

If all possibilities exist at all times as variable probabilities, I can begin to grasp the irrelevance of time as being necessary to arrive at meaningful insights about the universe. If time always exists as an infinite quantity, it may as well be zero because along an infinite timeline, all possibilities, even those with extremely finite probability, will exist.

I am wholly new to all of these concepts and as I stated, math might as well be a rapid-fire auctioneer speaking a foreign language. The above thoughts are the best I could solidify and I would love to know if I'm even in A ballpark... not THE ballpark, but at least A ballpark that is somewhere near relevant.

if a specific variable does not have a discernible impact on the resulting value, it is irrelevant to the equation. Such a variable may exist merely as a conceptual "comfort" to the human method of perceiving the universe, but that doesn't mean it serves any meaningful/rational purpose within the equation.

The variable may be meaningful but redundant. A database programmer would say that you don't have to keep a value in a column of the table, if you can calculate it from the other columns.

If all possibilities exist at all times as variable probabilities

Amplitudes, not probabilities. They are complex numbers, which is why they do the weird quantum things, such as two nonzero numbers making a zero sum. -- If you have 5% chance to win a lottery A, and 5% chance to win a lottery B, you cannot as a result have 0% probability to win either A or B. But a photon can have 5% chance to hit you if it goes through slit A, 5% chance if it goes through slit B, and 0% chance if both slits are open, if the amplitudes happen to be antiparallel.

What we see as probabilities, that's just a ratio between the squares of the absolute values of the amplitudes. (I don't fully understand why, so I can't tell you more about this.) On large scales those amplitudes give results consistent with our knowledge of probability, which is somehow related to the mathematical fact that if you take two complex numbers a and b, then |a|^2 + |b|^2 on average equals |a+b|^2 (the equation is true when vectors a and b are perpendicular to each other).

Your second paragraph is pretty accurate. Your third one, I don't really understand.

all possibilities, even those with extremely finite probability, will exist.

Possibilities with probabilities that decrease over time can be finite. Thanks to the expansion of the universe, the probability of a mind exist will likely approach zero, causing this to happen.