Nope. "Right now, over there" is a phrase which has no meaning on astronomical scales. There is no defined order for events which don't have a causal connection.
There exists a frame of reference in which the state that we see in that image takes place at the same time as we read about it today. There's another frame of reference where it happens billions of years ago, before the formation of the Earth; another in which it happens in our future, long after our Sun has evaporated into nothingness (Ed: There isn't actually, see below). All of these perspectives are literally, completely equally valid. They're all real.
Your parent's point was simple and practical, not bound up in relativity. Parent was merely observing that even though we see it (please do not launch off into a metaphysical discussion about "what is seeing"), if we were to go visit it, it could no longer be there for use to "use".
You seem to think I'm quibbling over pedantry. I want to make it clear I'm not talking about wacky theoretical physics here, let alone metaphysics— this is hard science. You can't avoid getting "bound up in it"; relativity is, definitely is, how our world works.
In our universe, "It could all be gone by now" not only isn't true, it doesn't even make logical sense. There is no one such thing as "now".
Now, "It could all be gone by the time we get there" is a different, totally practical and valid statement. But that's just because of the amount of time it would take us to cross that distance; it has nothing to do with the distance that light has already traveled.
While I agree you are not talking about wacky unproven theory, I am not sure I agree that you are not being a pedant. Your parent's assertion is most definitely plausible from the right frame of reference, and mainly written to elicit amusement, but you insist on getting bogged down in the details discussing how it is NOT plausible in other frames of reference, which is quite frankly, besides the point.
I guess I disagree it's beside the point. You say my parent's assertion is plausible from the right frame of reference— what frame of reference are you assuming my parent was referring to? Certainly not the one we're all in, where we can see there remains plenty of water.
I'm inferring you understood it as something like "a frame of reference which agrees with the theoretical frame of reference of a spaceship we launch today, at the time it arrives at the reservoir". That seems far from obvious to me— I find it much more likely that xhuang (like many other commenters on this article, I should add, not to mention the public at large) has been misled by pop-science into the thinking that something being twelve billion lightyears away means that right now, whatever we're seeing is actually twelve billion years in the past.
But that's exactly wrong! There is no actually, and what we see is as valid to call "right now" as anything else. And this is the universe we live in! Maybe I am a pedant, but this stuff is mind-bogglingly amazing when you can actually wrap your head around it, so I try not to miss out on a relativity teaching moment.
Anyhoot, we obviously both get it, so I'll wait on xhuang to say whether my comment was relevant to his point or not.
I would take the frame of reference of an observer at the location of the water because that is your goal - it's what is meant by "over there".
Could you resolve the "right now" issue if you took a picture of the event to said observer, who then compared it to a history of images and then said "oh yeah, 5 minutes later it was all gone, never to return"?
These seem like a closer representation of what people mean when they say "it's all gone now."
It's fine to get excited about strongly relativistic arguments but I don't think they have a place in talking about events at distant celestial objects.
The amount of distortion you can have between distances and times is bounded by the amount you let your reference frames differ. Between stars there is not all that much velocity, so time is a relatively stable concept. Sure it'll wander a few percent but nothing nearly as drastic as having no sense of 'now'.
Don't forget that when you bring relativistic speeds into the mix you can't agree on distances either. Are you prepared to argue that it's actually one billion light years away?
I fail to see how "right now, over there" fails to have any meaning when at this very moment that point in space does exist, the assumption is that we are moving between there and here without any lag (instantly) when comparing the sets of areas.
In our minds, where the comparison is taking place, we need not account for how long it takes light to travel. We can simultaneously hold the thought that we are here on Earth, and way over there, there once was a giant cloud of water vapor.
First you should read the Wiki article I linked, since it goes over it much more thoroughly than I can, and then maybe I can help if you still have questions. Here's the introductory paragraph to get you started:
Where an event occurs in a single place–for example, a car crash–all observers will agree that both cars arrived at the point of impact at the same time. But where the events are separated in space, such as one car crash in London and another in New York, the question of whether the events are simultaneous is relative: in some reference frames the two accidents may happen at the same time, in others (in a different state of motion relative to the events) the crash in London may occur first, and in still others the New York crash may occur first.
I emphasize again that this is the actual way the universe works, not theoretical physics. What you say about our brains holding the two ideas simultaneously in our head is true; our brains are wrong, and the statement "There once was a giant cloud of water vapor" is untrue, or rather, undefined.
Also: I fail to see how "right now, over there" fails to have any meaning when at this very moment that point in space does exist, the assumption is that we are moving between there and here without any lag (instantly) when comparing the sets of areas.
To move "instantly" from one place to another presupposes there is such a thing as "over there, right now", which there isn't. Your definition thus has no meaning. Isn't this stuff wild?
So what I take that relativity of simultaneity is showing, is that there is no "universal time" everywhere.
But this is all dependent on the positioning of the observers. The observers painted on the universal graph are all ones waiting for light to reach them. This is what is causing the confusion as to when is "now", as all the observers or points of awareness are separated in space. And I take it that, their separation in space is also what separates them in time... and thus each have different notions of when now is.
But can we not conjure an omniscient observer as our frame of reference? One who exists at all points, at all times.
Would he not be able to observe both the Earth on July 24, 2011 and what exists in the space of the water vapor cloud as Earth time is still July 24, 2011?
But can we not conjure an omniscient observer as our frame of reference?
Yes. We can not. In fact, that is precisely what the theory of relativity states: There is no privileged reference frame.
There is literally, actually no such thing as "what exists in the space of the water vapor cloud as Earth time is still July 24, 2011". As I look at my clock at noon on July 24, I see water. Someone at the reservoir will not see my clock strike noon for twelve billion years, my time, and they'll look around and maybe see no water. We disagree, but we're both right in our own frame of reference. Both perspectives are true.
Which makes sense if you think about it; your omniscient observer would have to agree with one or the other (or some other) disagreeing perspective. What criteria could you possibly use to choose between them?
Tip: "I'd love to explain it, but (I won't)" comes across as extremely elitist, and to some people, quite repugnant. If that's not how you mean to come across, simply omit that first bit before the comma, and you will come across much more amicably.
Whoops, I forgot my own rules. Relativity doesn't violate causality; Obviously no one will observe us to see the reservoir it before it happens.
Okay, so there's a frame of reference in which what we'll observe to happen to the reservoir tomorrow has already happened. It was much punchier the other way, though :(
I am no expert on this, but if you assume the cosmological principle which states that our universe is roughly isotropic, there is a natural set of observers called comoving observers who are at rest with respect to the expansion of the universe. One can define a universal time using the clocks of these observers. Presumably, this is what gives meaning to statements like the universe is 14 billion years old.
Well, again, relativity doesn't violate causality. No one sees an effect before a cause. That translates into the cosmological principle in that all observers will see the big bang happen before anything else, all observers will see stars form before planets, et cetera, so it all comes out in the wash.
Nothing about that privileges a comoving observer with relation to unrelated events, though; they'll have their perspective just like everyone else, and that will be that. There's nothing "universal" about comoving time.
http://en.wikipedia.org/wiki/Relativity_of_simultaneity
There exists a frame of reference in which the state that we see in that image takes place at the same time as we read about it today. There's another frame of reference where it happens billions of years ago, before the formation of the Earth; another in which it happens in our future, long after our Sun has evaporated into nothingness (Ed: There isn't actually, see below). All of these perspectives are literally, completely equally valid. They're all real.
There was a good discussion about this last time it came up here: http://news.ycombinator.com/item?id=1907271