The following is not a question: Can something come from nothing?

[Cato]

I like much of the thought in this post, but have a couple comments.

A backward flowing waterfall would violate the law of gravity, so saying no laws of physics are violated is a bit of a stretch.

The last sentence leaves me a bit flat; I'm not sure what you're after. Questions only resemble questions, but only mimic them. I don't understand what this means. It also sounds a little self indulgent.

Despite the fact that our concept of time and causality breaks down at the Big Bang, asking what happened before is a meaningful question. To arbitrarily claim there was no before because we can't see past what we call t=0 does not mean there isn't a t<0. I agree that it would likely be something very different than what we know; however our inability to understand this doesn't mean there is no before. I think it is important to consider, but we may never know. The questioning and pondering may ultimately be fruitless, but I can't support describing the question as meaningless.

[Alex K]

I like much of the thought in this post, but have a couple comments.

A backward flowing waterfall would violate the law of gravity, so saying no laws of physics are violated is a bit of a stretch.

You're wrong here. It does not violate gravity just as a ball flying upwards when you throwing it up does not violate gravity. It is merely unlikely that the thermal vibrations in the creek conspire to push a drop of water upwards with enough force for it to make the trip.

The last sentence leaves me a bit flat; I'm not sure what you're after.
Questions only resemble questions, but only mimic them. I don't understand what this means. It also sounds a little self indulgent.

"What is behind the sound of the color pink?"

It looks like a question, but it isn't

Despite the fact that our concept of time and causality breaks down at the Big Bang, asking what happened before is a meaningful question.
To arbitrarily claim there was no before because we can't see past what we call t=0 does not mean there isn't a t<0.

But now you're effectively saying: possibly our concept of time does not break down

I agree that it would likely be something very different than what we know; however our inability to understand this doesn't mean there is no before. I think it is important to consider, but we may never know. The questioning and pondering may ultimately be fruitless, but I can't support describing the question as meaningless.

[Angrboda]

I think the question as often posed incorporates misunderstandings, but the root question of why or how space-time exists at all seems logical.

[LostLocke]

Despite the fact that our concept of time and causality breaks down at the Big Bang, asking what happened before is a meaningful question. To arbitrarily claim there was no before because we can't see past what we call t=0 does not mean there isn't a t<0. I agree that it would likely be something very different than what we know; however our inability to understand this doesn't mean there is no before. I think it is important to consider, but we may never know. The questioning and pondering may ultimately be fruitless, but I can't support describing the question as meaningless.

I'm thinking that most of those in the science field that are positing that 'before' doesn't work for the big bang, aren't necessarily saying that there is 'no' time before the big bang, just that, like you said, it very likely does not function the same way we understand it here.
From our tiny blip on the radar lifespan, time starts at point A travels in a straight linear line to point B. That's all we really need to know to function in life. However, for those of us paying attention, we know it's been shown that time is a lot more flexible and variable than that. We've already demonstrated that time travels at a different rate in orbit that it does on the ground.

I think all they're trying to do is get our minds set that our normal concept of time won't work when we're dealing with 'before' the big bang. We don't know, but it is a real possibility that there was no time before. Or, another fun one to throw at people and watch their faces, is that something did in fact cause the big bang, but that something hasn't happened yet.

[John V]

Why did the cascade so obviously violate your sense of time, while the other parts of the creek did not? The reason is entropy: the cascade is, from the physics point of view, a very irreversible process which produces lots of entropy. The creek running its course quietly produces entropy as well because of the friction the water experiences, but much less so than the cascade.

The surprising thing is this: nothing in the backwards-running movie violates the laws of physics.

Er, water falling (so to speak) up seems to violate the laws of physics to me.

Note what has happened: we use the words which have meanings in our everyday lives as well as in science, and try to apply them in a scenario so different that none of them retain any meaning. Two things spoil the question: if there is no universe full of particles doing their statistical dance, there is no notion of an arrow of time, even if we assume that time as a continuous parameter exists. However, if we let even go of this, if we feel compelled to talk about the creation of time itself, all meaning is lost, and the questions we utter merely resemble questions, but in reality only mimic them.

In appealing to a time or state or what have you in which the laws of physics as we know them don't apply, you're appealing to the supernatural, like the theist.

[Alex K]

Er, water falling (so to speak) up seems to violate the laws of physics to me.

See my reply to Cato: the opposite of water falling down is water being thrown upwards.

[John V]

See my reply to Cato: the opposite of water falling down is water being thrown upwards.

Your reply to Cato appears to be a false analogy. Yes, an object can go up if a sufficient outside force is applied to it. In the ball example, there is such an outside force. In the waterfall example, there isn't.

[Alex K]

See my reply to Cato: the opposite of water falling down is water being thrown upwards.

Your reply to Cato appears to be a false analogy. Yes, an object can go up if a sufficient outside force is applied to it. In the ball example, there is such an outside force. In the waterfall example, there isn't.

My point: why isn't there such a force? Because it is unlikely that the molecules in the water (which possess enough energy to do so) would conspire to exert such a force. This would correspond to a significant downward fluctuation of entropy, and is therefore unlikely. That's precisely how the arrow of time arises.

Compare this to an idealized bouncing ball bouncing and bouncing up and down on a surface without friction. Look at it backwards and it will be precisely the same process, because Entropy is constant.

[Angrboda]

Your definition of entropy and the arrow of time seems circular. Water falls because there are more possible states it can be after than before, yet this is just the definition of the arrow of time itself, so you haven't really explained the arrow of time, simply shown something that occurs if you assume a specific arrow of time. (Which may be violated, e.g. fluctuation theorem and time-reversal interpretation of QM.)

[John V]

My point: why isn't there such a force?

Because it's against the laws of physics.

BTW, IMO you can make your main point without claiming that a waterfall going up doesn't violate the laws of physics. To me that was unnecessary and destined to cause distraction.

Plus, what do you think of the second part of my initial post? Just because you're not positing an intelligence doesn't mean you're not appealing to the supernatural.