Where Did Time Come From, and Why Does It Seem to Flow?
nautil.us
nautil.us
I can't figure out if they are reputable sources that dabble in more abstract concepts, or if they are some kind of pseudo-science platform for crazy founders.
I think it's just generic post-modernism.
The flow of time is an illusion, and I don’t know very many scientists and philosophers who would disagree with that, to be perfectly honest.
So while I tend to side with you that the philosophy bit is probably unnecessary, I would contend that there may be surprising usefulness in the nonsense solutions (or they're just nonsense; it's hard to tell looking at the future work that hasn't been done yet).
What was frustrating for me was that he didn't seem define "the flow of time". I would have defined it as the idea that the universe is not translation invariant along the axis measured by clocks. The truth of that statement is practically tautological, as he already agreed that clocks do measure intervals and that measurement inherently breaks the translation symmetry. Then again, cosmology isn't my field so maybe I'm missing something.
While the implications and meaning of time in a cosmological sense are certainly interesting, the piece's angle of debunking naive common-sense views of time is a bit too aggressive. In daily life, the common-sense view of time is perfectly rational.
Perhaps the audience is physics grad students, I dunno.
Huh? The flow of time, and "time passing" is the most universal and common understanding (and feeling) of time.
I kind of suffered through Physics in undergrad but this makes me wish I took more as an elective.
I see this repeated to point that "hence we are not really conscious" or not really in control of ourselves.
But, to me, an obvious answer is that our "thought" is not just the "talk-to-myself" like thought, but also faster unconscious processes, that still weights things and combines our memories and "personality" biases in the decision making, it's just not like an 'inner-dialogue'
Well, isn't there a common time for the entire universe? If we ignore being near massive objects, then observers travelling with the expansion of the universe - i.e. those those who don't see a dipole in the cosmic microwave background (CMB) - then the redshift of the CMB acts as a kind of clock. With the usual cosmological assumptions of isotropy and homogeneity, then there's a big clock for everyone to use.
According to relativity, isn't the view that the universe is rotating just as valid as the view that you are rotating? It all depends on your perspective, and there is no privileged (absolute) vantage point or perspective.
Isn't that so? And if it is so, how can this physicist be ignorant of this?
[Update: Oops. I missed the "and stop" bit. That's what I get for reading HN while I'm half asleep. Sorry!]
The same applies to rotation. Accelerometers placed on my floor and on my body will detect the difference, and both will agree.
Of course, I may be ignorant of his actual intent.
To put it differently, if I pass someone on the train moving at constant velocity, there's no experiment that I can perform which proves that I'm moving while the other person is standing still, or vice versa.
However, if I'm in a centrifuge, instead of on a train, then I can figure out which one of us is moving by measuring who is pressed up against the wall and making funny faces.
http://en.wikipedia.org/wiki/Mach's_principle
An important implication of relativity is that when you push something, you do not change it's velocity. You change it's acceleration. It's a small but important distinction. Acceleration is more fundamental.
"Events occurring in sequence" is the same thing as "the flow of time", in my understanding at least. What else does "the flow of time" refer to? I fear there's a subtle point being made that I don't quite grasp.
He gave a good explanation of time. Right before the big bang, the universe was in a 'perfectly' ordered state. Since the big bang the universe has become less and less 'perfect'. What we think of as Time is really just things getting less and less organized.
All our "time" measures are based on cyclics movements.
Make yourself a question, if ALL movement stop (include atoms), will time pass? will the arrow of time advance?
It is generally not useful to consider the consequence of falsehoods.
http://en.wikipedia.org/wiki/Thought_experiment
I think this one runs some risk of begging the question, though, so unless we make it significantly more precise we're unlikely to get anything useful out of it.
Sure, but that doesn't describe "What if radiation and quantum noise stopped moving?". That's just a dumb question. We can't really derive anything interesting from its consideration. It's along the lines of "What if you dropped a rock and it didn't fall?" What if?
In any event, I agree that the question is not likely to be useful, but as I said I think that is because it subtly begs the question in a way that isn't likely to be clear without it being stated quite a bit more formally.
"That's just a dumb question."
While "there are no dumb questions" is an overstatement, I think your tone throughout this has been unnecessarily hostile (not toward me, mind you). You could have done more to educate, you chose to abuse, and in a way that stepped into inaccuracy to boot.
Perhaps my example was not appropriate, because I described something that could happen (which is what might allow us to have a useful thought experiment). I couldn't think of anything to match the irrelevance or off-basedness of the radiation-stopping question.
>You could have done more to educate, you chose to abuse
"Abuse" is quite hyperbolic in this situation. And you're right, I could have done more to educate, but I also don't have infinite time to give helpful and constructive corrections to every stupid comment on the internet. Sometimes you just make it clear that the comment is stupid, so no one else accidentally takes it as reasonable, and leave.
I certainly didn't mean it in its strongest sense.
"I also don't have infinite time to give helpful and constructive corrections to every stupid comment on the internet."
But you have time to give poor responses. I suggest you reorganize your time.
"Sometimes you just make it clear that the comment is stupid, so no one else accidentally takes it as reasonable, and leave."
I don't think that's what it tells people. You didn't explain, in a useful way, why it was unreasonable. So all people know is 1) someone on the internet thinks this comment sucks (which is almost tautological), and 2) comments are more likely to be met with negativity than assistance (which is harmful to our community).
That's pretty much asking "If time stops, will time pass?" - which doesn't really answer anything. Stopping all movement is not something we ever see in the universe (well, we couldn't see or experience it anyway). And yet we see movement - we see everything changes.
I think time may be a human construct to order these changes, but it is also a property of the universe (whether fundamental or emergent) which allows such change to happen in the first place.
If on the other hand it is the opposite (and based on the way we experience universe, I'd rather think it is the opposite) - then "movement" would be the emergent property of space and time; and both space and time would be more fundamental properties.
In either case I don't think "illusion" is the right word, as it implies something non-existent or unreal. And even if it is an emergent property, it would still emerge from some more fundamental properties and thus would be quite real.
If it isn't conscious thought and motor signals, then what is it?
For example, our mind processes thousands (or millions) of signals coming from our senses without us needing to "think" about it.
https://news.ycombinator.com/item?id=8519764 ("We Are All Confident Idiots")
Memory is reconstructive. Memory is aspirational. Memory is an evolutionary adaptation. Memory is lossy and iterative. Memory is an unconscious advantage-seeking collaborator.
People are (for whatever reasons) given more credit for conscious decisions than for unconscious reflexes, so it is in their interest to make it seem as if their actions were under conscious control. So memory does that for them.
I highly recommend this documentary as well. Thanks for posting it, I will be listening to it again today.
This would also be the only way to simulate consciousness in AI. Makes total sense. We're AI.
Isn't time (like darkness) merely a description of a state of space / matter?
It was/wasn't here, now it's here?
The operative phrase here being "you don't see". Of course, seeing is a matter of perception and perspective. It could very well be that time is flowing "backwards" and eggs are in fact reassembling themselves, but we are just perceiving time in reverse.
You know, when I hear physicists try to tackle philosophical problems, it's usually kind of embarrassing. These guys are rarely trained in philosophy and are out of their depth.
As Feinman famously said to his own students, "Shut up and calculate."
I wish more physicists would follow his advice, and leave philosophy to philosophers.
Having the background of being extremely well-trained in one field gives a different perspective than the typical "echo-chamber" of the elite in any specialty.
If you know something they don't, why not try to start a dialog instead of criticizing and dismissing?
Well, that wouldn't be so bad if they stuck to explaining the results of their experiments, but when they stray from that on to philosophical subjects, they're really no more suited to talking about that than any other non-philosophically trained layman.
It might help if they toned down the rhetoric a bit and make it clear that they're speaking about something that they have no training in.
On the other hand, I suppose I should be grateful that they're exposing the general public to ideas they might not have otherwise thought about, even if they do so clumsily and their conclusions are highly suspect.
Of course being an amateur doesn't lend a high degree of credibility, but certainly more than the average Joe.
Being neither a philosopher nor physicist by training, I'm probably unqualified to arbitrate that debate. But it is worth noting that when qualitative approaches meet quantitative approaches, the quant guys seem to pretty persistently come out on top (e.g. Google with programmatic advertising vs. the good old boys selling ads by taking the client out to a steakhouse. Which model overwhelmed the other in mere months?)
One could certainly make the argument that the practice of science and the creation of technology "gets results" (though there are counter-arguments having to do with human agency or free will, with causality, and with our perception of the world and whether what we perceive is real and whether what looks like obvious cause and effect is actually what's going on here).
But whether something "gets results" may have little bearing on whether it is true or an adequate explanation of the world.
However, if you could break an egg and then unbreak it, that would be remarkable (and observable), whether you did it tomorrow or yesterday.