It is a proven fact that we can know what has happened in the past because we know how long it takes for light to travel in a year. So we can tell what the universe looked like X million years ago, XX million years ago, XXX million years ago... But we can't know what is in front of us. Because light travels in one direction (except for refraction etc etc). So next year might be the last year of the existence of the universe.
In the early 1800's a guy by the name of Laplace postulated that if one could know the direction and momentum of every particle in the universe, one could calculate the future. This entity that knows it all is called "Laplace's Demon". This has philosophical implications, as this Demon could calculate your future, thus how could you have free will? There is no "Laplace's Demon", but we do know a lot about how things are progressing into the future.
with this statement you have negated your original post, at least provided a caveat. what are the "things" that could possibly change? perhaps those immutable laws of physics we hold so dear. perhaps the speed of light is not so constant as our limited observations have lead us to assume.
Is time linear? We perceive it as linear but physics suggests it is more complex than that https://www.space.com/29859-the-illusion-of-time.html
What you are saying is meaningless. You will have to do a lot more to specify why we can't know what's in front of his. The correlation you seem to be trying to make does not make sense.
Light has a "shift" if it is coming toward us it is an ultraviolet shift. If going away from us a red shift. But what it say about the future I know not.
Unless, of course, Time (so, I guess, you might say Light, as well) is running backward, in which case you should speculate that we could, unknowingly, be moving into the very FIRST year of the universe!
If time is running backwards, why is the universe expanding? Just to be clear, I am only playing with ideas. The thread isn't meant to be taken very seriously.
That was prophetic. Do you feel up to helping me search for Doc Brown for that DeLorean? I think many of us could do with a do-over.
Just a minute while I reset the town hall clock to where it might rightfully be, unless time has moved on either forwards or backwards. I find the old story about going back in time and readjusting one thing, fascinating. Course Captain Kirk would not allow it...
It has to do with the idea of Negative Space. You see, a vacuum, with nothing in it, is "full," of nothingness. So, as to this idea of how did the first "stuff" of the universe just appear, out of nowhere: really, it was the break down waste, the leftover excrement, after all of the universe's Nothingness, had been "metabolized," if you like. I'm being a bit whimsical, myself.
What a pity we can't do that with nuclear waste, or even plastic. To be serious for a moment, I have never believed space was ever a perfect vacuum. There were always forces we can't see and some which may not now exist.
You sound very scientifically- minded. It is funny, then, that you do not take context into consideration, in evaluating the meaning of a post (for, as you may have heard, "everything is relative"). Will Readmore had ended his post, "we do know a lot about how things are progressing into the future." This was in a post, addressing Laplace's Demon, as it would, theoretically, apply to free will. Therefore, by "things," Will R. should be taken to be mean all sequential processes, of which we are aware. I think it would be clearer, if I were to use an analogy. For this, it will help if, in addition to being scientific- minded, you can also employ some capacity for imagination. So, picture a large lilly pad, with a pancake (or padcake) of water, in its center, which is our universe. And we are microbes within it-- but very smart, microbes. We have studied all the microbacteria, recorded the varying force, which is the subtle movement of water, in our Lilly's pond, even were able to, by combining data from our best telescopes, with advanced mathematics, get a glimpse at the turbulent fluctuations at our universe's outermost edges, where some microbial theoretical physicists, have postulated a phenomenon which they call "breeze." Eventually, from learning so much about it all, we can understand how each force impacts on every other force, which, through their interactions, like so many independent wheels, joined in a clockworks, keep time, in an eminently predictable manner (remember, we are discussing the silly notion of Laplant's Demon, in which nothing but measurable, physical forces, are behind your decision as to what you eat for dinner). So, as I was saying, those microbes have it all figured out, down to an exact science, as we say, when a frog, hops onto their pad, throwing everything askew. In a frenzy, trying to explain this new phenomenon, through their microbial science, they are unaware of the approach, just under the water's surface, of a hungry cayman, which will, momentarily, emerge, open- mouthed, then snap his jaws shut, on the frog & leaf, both. Thus, will begin a new trip, down the cayman's gullet, towards its stomach-- with the microbes, as well, along for the ride.
what i was referring to was this supposedly "known fact" that we could know what happened in the past. if the laws of physics as we know them are not a constant, then our understanding of the past is a hazy guess at best. with all of our theories concerning the origin and age of the universe, the creation of the cosmos and the patterns of energy that direct our reality we are just whistling in the dark.
That is well said. It, however, relies on the idea that the physical laws are (significantly) in flux, as opposed to having remained constant, or immutable, for most of "time." If I may speculate, you seem to mix up our understanding of physical principles, at any given point, with those "laws," themselves. Or are you suggesting that physics is the study & application of a thing which, in its own nature, is unpredictable?
They get called laws, because they are relationships that haven't ever been detected to be broken, even though they get used all the time. In fact, laws don't explain any mechanism, which is the difference between law and theory. If there is a law for which it is found that the law has changed over time, then that would get a lot of study toward understanding how much, why did it change, etc. and there would be work to identify what bearing that has on other results that could possibly be affected by that change - is the universe a different age, etc., etc. Depending on what changed, it would be a big deal. Humans failing to detect or understand something doesn't mean that the thing, or physics itself is unpredictable. It just means there are limits to the most advanced understanding that we have today. There are questions for which humans have no answer. Throughout history, that's been the challenge of science. I think it's not known the degree to which physicists want to BREAK physics. That is a dream which physicists the world over strive to achieve. When even small pieces break, it means whole new areas to study, whole new opportunities for finding answers to questions that have no answers. The fact that the largest, most complicated piece equipment ever built, the facility at CERN, CONFIRMED ideas held by theoretical physicists, ideas like the Higgs particle bringing those ideas into the realm of experimental science, was seen as shockingly disappointing. The prayer of physicists everywhere was that something significant in the standard models of physics would simply crumble. By confirming what was already strongly suspected, it really didn't even identify where to go next to try to find answers!!
Another Readmorian lecture-- surprise, surprise! You'll try to force one of your symposiums in, anywhere you think you see a crack. Well thanks, but I do not need a class from you, on why science calls certain principles, "laws." If you had misread my question to undertheice-- as seems to happen quite a bit, when you read my words (I cannot speak to any interpretation difficulties, you may have with other posters, as well)-- I had only been asking for her to clarify her own statement. So it might be best for you, like me, to just wait for that reply, for your opportunity to go to LectureTown.
Of course Heisenberg proved this isn't possible. It is impossible to know precisely the momentum and position of any particle.
A law is just a theory that is virtually beyond question. I noticed that the online definition is WRONG. "What Is a Scientific Law? Like theories, scientific laws describe phenomena that the scientific community has found to be provably true. Generally, laws describe what will happen in a given situation as demonstrable by a mathematical equation, whereas theories describe how the phenomenon happens." Firstly, we don't prove things in physics. We disprove them. And theories that have stood the test of time become defacto laws. For example, energy is conserved - cannot be created or destroyed. That was first proposed as a hypothesis that became a theory and eventually was called a law. But it isn't really a law. In fact we have found that violations can occur for very short periods of time - ala Heisenberg!
Absolutely. The daemon would have to be supernatural in various ways. But, it still gets used in making various arguments where that fact doesn't matter.
Yes, that definition was really bad! I agree with what you've said with one exception. Since a law doesn't describe a mechanism, one can't really turn a theory into a law. One would have to remove all the mechanism, which is really what a theory is - a description of a mechanism. I think laws come about by observation that no exceptions have been found. Your conservation of energy example is clearly a law, as it includes no description of a mechanism. Your case where the law may not be true is interesting. There are other laws that have limits on where they are true. I imagine it's possible to have laws that are closely associated with theories. I haven't heard of Einstein's famous equation that is part of his relativity theory being called a law, but perhaps it could be. Have you heard it referenced as a law?
our understanding of physical principles? we have nothing else to go on but our "understanding" of just about everything. such principles may exist outside of our "definitions", either unchanged or wholly different from our understanding, or they may not exist at all. do we alter those principles by our mere observation of them or are we simply altering our perceptions of them to suit our restricted frame of reference? the older i get (and i'm pretty damn old), the less i take for granted. in a world where nothing is taken for granted even the wind becomes a source of wonder. is it really the play of elements, high and low pressures and the rotation of this sphere or is it perhaps the breath of god, maybe even millions of invisible pixies imitating the motion of our atmosphere? yes - i've had a great deal to drink today, but doubt is at the very heart of the scientific method and doubt is what rum brings out in me. perhaps rum is science.
