No evidence of time before Big Bang | Hacker News Reader

No evidence of time before Big Bang

nature.com

50 pointsjapaget40 comments

Isn't time, somehow, a human abstraction?

I mean, what really exists is movement. Earth spins over itself and we call it a day, Earth circles the Sun and we call it a year, a few quartz electronic pulses are called a second, etc. We use these events to measure time.

Before Big Bang there was no movement, therefore, there was nothing to measure time with. If there's nothing to measure time with, there's no time.

If a tree falls in the forest...

I love to see the connection between science and philosophy. I used to see philosophy as useless, and in modern practice it often seems that way, but I think it's fair to say that all science has philosophical roots - in this case, what is time?

Isn't time, somehow, a human abstraction?

What about space? Another dimensional abstraction? It becomes a semantic argument. A valuable one, but still - it is quite possible (probable?) that all human understanding is an abstraction of sorts. The fun part of engineering is learning to build stuff using the abstractions that we have experimented with enough for their behaviour to be predictable to some extent.

Periodic movement is what we use to measure time, yes. But I can't imagine that time is simply a human abstraction. Just because there's nothing to measure time with doesn't mean time doesn't pass, right?

My brain doesn't like the idea of time in the context of relativity. Just because the relative (nominal?) measure of time changes as the forces of the universe may or may not cause it to doesn't mean the absolute (real?) period I wait for the train every day changes. Just because the clock stands still while you're moving away from it at light speed doesn't mean "time" hasn't been spent moving away from it.

(I use nominal and real because, oddly enough, economics is the closest thing I can relate this to.)

Wait, this guy tries to go deep and gets downvoted, while

"Also: no evidence of Pop Tarts either." Gets 5 upvotes?

That makes about as much sense as this article.

True but if I travel away from a clock at light speed, time doesn't move anymore but I'm still moving.

Personally I like the idea that the big bang is a cyclical event - the universe expands until some point, then it collapses again. At some indeterminate point it expands again. Whether or not Earth gets recreated is for someone else to ponder.

Nietzsche did, the concept of Eternal Recurrence is the basis of his philosophy.

I can't agree more. What I see time is as 'infinite now'. That's all that exist.

There is now, now now now now now & now...

We think it's tomorrow in Australia already but it's now. I can imagine that there was 'now' before Big Bang, since Big Bang happened in the now.

Before Big Bang there was no movement

How was the Big Bang triggered then?

Let go your preconceptions; cause and effect, this "trigger" of which you speak, is an idea you have built living in this universe with these physical characteristics.

> Before Big Bang there was no movement

Prove it.

It's possible there were other universes.

> there was nothing to measure time with

There was nothing inside the universe to measure time with.

> It's possible there were other universes. Prove it.

You made the assertion, the burden of proof is on you. I pointed out how your assertion could be wrong.

So what is the consensus about what time is? Is the following a valid understanding of the post title: "No evidence of stuff going on before stuff existed" ?

The "consensus" is that time started at the Big Bang and there is no meaningful referent for "before the Big Bang". However, the consensus is also that the theory that says this is flawed in several known ways, not least of which is the lack of unification between quantum and relativistic gravity that you may have heard about. This is the consensus theory not because it is perfect, but because nobody has yet managed to put together an alternative that does better across the board. Really the upshot is that nobody really knows, even for small values of "know".

>"So what is the consensus about what time is?"

Kant said time is an a priori condition of human experience. This is to say that time is how we structure experience, and not something existing as a thing in itself.

Penrose would be a safer bet if he hadn't written "The Emperor's New Mind". Having completely flamed out on a subject I consider myself competent enough to judge him on, I'm much less willing to bet he's right in an area where I am less confident and knowledgeable.

I have never read "The Emperor's New Mind". What are its flaws?

It's been a while, but if I recall Penrose basically attacks the notion of "stong AI". Others, e.g. Scott Aaronson, have ripped his argument to shreds. But not to dismiss Penrose's argument too quickly, Aaronson did devote an entire university course to presenting the counter argument http://www.scottaaronson.com/democritus/. I think there is a case to be made against strong AI along the lines of "just because a posteriori you can model anything digitially does not make it so", but apparently Penrose failed. (And don't get me wrong, I'm not the guy to make the case either.)

I'm always suspicious of phrases such as "ripped his arguments to shreds" especially in such a young and contested field as AI and doubly when dealing with the difficult issues of sentience and Strong AI...

I'm not accusing you of anything, but as a general comment, without necessarily supporting them, the response to his arguments on this issue often seem to involve overly emotive language.

Normally I regret using inflammatory language, but in this case I think it invokes the fervor I have seen in most every defense of strong AI I have ever read. Personally I am not a proponent of strong AI. Proponents have, however, built a strong case that tends to put opponents in the position of having to prove a negative.

I don't think it's fair to say that Aaronson's course was devoted to debunking Penrose. It just happens that Penrose is very good at explaining these concepts, so his (wrong) book on consciousness (which contains a lot of physics) was used as the "textbook".

Yes, devote was too strong a word. He could have covered everything in the course without using Penrose as his straw man. The point I meant to make is Aaronson builds a considerable intellectual and theoretical case before he uses it to knock down Penrose.

as another poster mentioned, Aaronson has done a great job of covering this -- waay better than I ever could. But the TL/DR is that Penrose believes there's something quasi-magical about thinking that can't be done with Turing machines, and therefore needs all kinds of special physics to get going. It' just so patently naive and absurd to a working computer scientist that it makes me suspect his ego/judgment ratio is a bit high.

Is your claim that we understand consciousness and thus we are certain that it can be implemented algorithmically or that it can be implemented algorithmically no matter what or something else entirely?

pretty much "it can be implemented algorithmically no matter what". There is just no evidence that the physical brain takes advantage of subtle quantum effects to do what it can do; it's extremely unlikely that any machine could do so at normal body temperature.

Intuitively, I don't see any vital need to introduce special types of computation to explain consciousness. It seems very likely to be a phenomenon that emerges from the right kind of information processing, regardless of the physical nature of the computation.

Given a large enough sample of random noise, you can find any finite pattern in it, akin to the infinite monkey theorem. The human mind is biased toward patterns.

I asked my astronomy teacher about this a week ago and told him the same thing you said- I asked him if it would be any harder to find concentric pentagons (if that's what they're called) in the WMAP since it is such a huge data set. My teacher told me that he didn't read the paper, but one of his grad students read it and pointed out that the man doing the analysis of the data didn't account for the probability that those patterns would be there anyway, apparently a common mistake. I wish I knew the proper term that he used, but the semester is already over.

"No prior" is, I guess, the term he used. There's some prior probability of finding circles in "normal" noise. It's only news if there are more circles than that. And there weren't.

True, but if the first humans on Mars were to find the complete works of Shakespeare buried under the Martian soil, it probably wouldn't be prudent to dismiss it as a cosmological fluke.

Not least because of the astoundingly small number of monkeys found on Mars ...

True, but try sampling the CMB for long enough and you would find a few lines of Shakespeare in some encoding somewhere.

Honestly, we have the statistical techniques needed to figure out whether a given pattern in the CMB is real or not. I'm no statistician, but folks that are can do this kind of thing for breakfast.

if you choose the encoding such that each letter in the alphabet encodes some Shakespearian paragraph, then you can find many lines of Shakespeare on this very discussion.

The summary says they are just disputing that concentric rings of uniform temperature in the cosmic background radiation are caused by oscillations of the universe, that is, multiple big bangs.

That's not to say that there aren't oscillations, just that these aren't a reflection of them. At least that's what I got from skimming, didn't bother to read the whole thing.

It'd be a little arrogant to say with certainty what happened before the big bang. I think the headline is misleading, very misleading.

>"Penrose, however, thinks that the Universe's great uniformity instead originates from before the Big Bang, from the tail end of a previous aeon that saw the Universe expand to become infinitely large and very smooth. That aeon in turn was born in a Big Bang that emerged from the end of a still earlier aeon, and so on, creating a potentially infinite cycle with no beginning and no end.

...Penrose's idea is being challenged by three independent studies..."

Did that idea (turtles all the way down) really require a scientific challenge?

http://en.wikipedia.org/wiki/Turtles_all_the_way_down

I thought the Big Bang theory ONLY dealt with what happened right AFTER the universe was created.

I always thought that cosmologists have been trying to correct the popular notion that the Big Bang also describes what happened before the universe was created.

The jury is still out.

Gurzadyan dismisses the critical analyses as "absolutely trivial", arguing that there is bound to be agreement between the standard cosmological model and the WMAP data "at some confidence level" but that a different model, such as Penrose's, might fit the data "even better" " — a point he makes in a response to the three critical papers also posted on arXiv5. However, he is not prepared to state that the circles constitute evidence of Penrose's model. "We have found some signatures that carry properties predicted by the model," he says.

My money's on Penrose.

I only read the BC paper (Moss et al, [3]), because I knew one of the authors (and he's a smart guy). Anyway, they show that you can find triangles just as easily, and that you can find similar circles in computer-generated random data with the same properties as the background.

At the same time, Penrose likes to be controversial.

So I guess I'm saying that I'm willing to take your money...

From an Bayesian/Occam's Razor standpoint, Penrose's data could fit the data "even better", but as it's (arguably) a more complicated model, still have a lower posterior probability.

Would a universe with infinite time extent be easier to believe than one with a definite start point? I have enough trouble merely comprehending the possibilities, much less assigning prior probabilities to them.

Also: no evidence of Pop Tarts either.

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