...that I never realized until the other day. With the Earth, space and the universe constantly moving, time traveling 5 minutes ago to the same place you are standing would cause you to end up in space and die. You’d have to factor where the Earth was for the period you want to go.
That version of time travel was solved by Mr. Peabody's Wayback (WABAC?) machine. Mr. Peabody would have his young friend Sherman set the machine for a specific time and place - like the charge of the light brigade, or whatever. He and Sherman could then fix some problem with that history in a Rocky and Bullwinkle sort of way before coming back home.
The corollary... Time does not exist. Everything that ever happened or ever will happening is happening. It is merely a matter of being in the correct space. That is, time does not exist. Only space exists along with those effects observable because of mass. Since only space exists any given point in "time" is merely the observation impact of an object with measurable mass interacting with the space around it.
...and, there certainly are problems with how we could use time travel even if such travel were possible. It's fun to think about. I've heard that the "many worlds' cosmology has some rather startling ideas about how change can simply cause a new universe to split off. So, one could think about how that folds into the problem of time travel changing past events.
Could be. And that's why bringing the dinosaurs back to life if we figure out time travel wouldn't work because it would be a far too big distance to travel. Millions of years in space and time.
Time travel doesn't make sense to me. To travel anywhere, it has to exist, where it is you are going to. but, wait a minute, the past only exists as memories, and the future only exists as imagination. both are in the mind, and exist only in the abstract, so how does one travel to them? Now, some posit that the past and future are concurring dimensions. Well, if that is true then if you go somewhere, it's a place that only looks like the past, because wherever you are, it is "now". "now" is never the past, It might look like your past, but it cannot be your past, only a particular in the now that looks like it. But, it doesn't make sense, really Why would such a thing exist? concurring dimensions that look like our past and future? I suppose it's possible, but, I'll file it under "I'll believe it when I experience it". Moreover, there are no absolutes. How do you go to an absolute point, when, at the atomic clock level, is shifting at the very moment of arrival. Additionally, our clocks and dates are completely arbitrary. When I think it about it, time really doesn't exist. It only exists in the abstract. Like numbers, they don't exist. But, they do exist in the abstract. You say, well numbers do exist. take a car, for example, it's 'one' car. No, it's a car. The number 'one' is a mental value we project upon the object. the number 'one' only exists in the mind. Similarly, 'time' is a 'mental value' projected on reality. the only thing that does exist is 'now'. But, absolute now is unobtainable. So, at the heart of this conundrum, is a mystery.
'You'd have to factor where the Earth was' relative to what? Is there any point in the universe that is 'fixed'? I think this is another reason that time travel, if possible, would just collapse everything. It would all fall apart. Which probably means it isn't possible.
~ Time travel is too expensive for the average person - even if you go coach. However there is always the Magic Mushroom Express .
Dadoalex, could you please explain the phrase about mass being important in the comprehension of the fiction of time? Please try to refrain from using any specialized physics words to the extent possible. I have a History graduate degree, so be gentle.... I am trying to get a grasp of this but have virtually no math and physics knowledge. I failed 11 of the 13 math exams in high school 50 years ago, (except for Geometry and Trigonometry which miraculously I grasped), and the President of my college had to explain sets to me in baby language. I asked for help in a Physics forum, but they wouldn't provide any. One person blew me off as incapable of understanding. I responded that they were incapable of, or reluctant to transmit important knowledge to those hungry for it.
Patricio Da Silva, I have the same difficulty as you accepting that people speak of time travel and places in the universe, yet they presumably do not exist. I also cannot grasp why science tell us Time can be warped, curved if you will by gravity, but yet Time is not real. I furthermore cannot grasp how a forest I observe is not real, yet the person next to me sees the same forest. How could it be a fiction to two different observers, or a thousand, etc....? If tens of thousands of people go to see the Grand Canyon every year, what is the explanation that all of them are observing something different and/or something which is not real? I wish I understood what they mean, but it appears the vocabulary and composition of the languages they use to explain these things are not quite adequate. By the way, if you are Portuguese, (or even Brazilian-Portuguese, you may be interested in the fact that there is a large boulder in Massachusetts near the shore which has the coat of arms of Portugal and the name Manuel Corte Real carved upon it. Samuel Elliott Morrison wrote about Portuguese explorations by the Corte Reals in North America, but for some reason a professor at Brown University I told about the carvings refused to believe they visited the northeastern coast of North America! I saw the boulder several times over the years and it is not a fiction.
I should have written "Miguel" Corte Real, not Manuel. (I automatically associate Manuel or Manoel with the Portuguese and Miguel with Spanish. Anyway, it makes sense that it is Miguel, one of the sons of Gaspar Corte Real, because perhaps he wrote this marker during his quest to find his father who was lost on a voyage of exploration. Ironically, that area of Massachusetts attracted a lot of Portuguese immigrants from the Azores a few hundred years later who worked in the fishing industry. It is still one of the few places left in New England where one can purchase bacalao prepared in the authentic manner: the greater Fall River/New Bedford area. Fall River was traded to Massachusetts for Cumberland by the State of Rhode Island and Providence Plantations, where I was born. It is on the southeast side of Narragansett Bay, which was explored by Guiseppe Verrazanno. It is said by one historian the local native tribe which he described as tall and handsome, either the Narragansetts or one of their subject tribes such as the Wampanoags, made him an honorary chief. I also forgot to close my parentheses, something I am sure someone will notice.
Ooops, mistake after mistake, Gaspar was one of the sons. He and Miguel were looking for their father, Joao Vaz Corte Real. Okay, last correction, I give up. If anything else was mis-stated, I can only plead old age.
Another problem with time travel is with going back to a time before you built the machine. Since for time travel to work, it would mean that every event past and future has to "exist" and be set at their fixed position, then there's no past that exist where you can use your machine before you created it and, on the other hand, this would mean that we don't really have free will or destiny since to go to a set time in the future would mean that this future is already existing and available for us to travel to thus meaning that no action that we take today can alter the future...
Time travel if possible, could mean one could go back into the past. Where history has been written and events happened. But impossible to go into the future, it hasn't been written yet, it has yet to happen. It's like having six sheets of paper where you written your story on the first 5 pages. You can go back to revisit what you have written, perhaps make corrections or not. That I'm still debating. But you can't go to the 6th page to visit or make corrections. Nothing has been written on it yet. It has yet to happen. What will be written on the 6th page hasn't taken place yet. So if I made myself clear, one would be able to go back in time, but not forward. Now if one could go forward, that would mean we're all living in the past and the future has already happened, we just don't know it. But considering we think we're living in the present, then the future remains a blank page which doesn't exist yet.
There's no past where you or your machine exist either. You'd either failed, get destroyed or invalidate all that came after the point in time you visited, including you creating your time machine...
Didn't Roger Penrose have some sort of time-viewpoint where this whole problem was handled by not having the "dimension" of duration exist within time at all? And no, I can't even begin to explain that, just to say that if all the notes of Beethoven's 9th were to be all played at once we would still have the symphony, though it would sound like just one explosive sound, (or sorta kinda, you tell me.) And didn't Philip K. Dick have something like this in his "VALIS" where he thought that we were still living in the First Century? https://dorseteye.com/the-empire-never-ended-philip-k-dick-valis-and-the-psychopathology-of-war/
"Patricio Da Silva" is my Brazilian alter-ego, as I'm a big fan of the Samba/Boss Nova and Brazilian Jazz. My name is Patrick, and I picked 'Da Silva" as it is to Portuguese what Smith is to English, i.e., one of the most common surnames, noting that my Avatar is Antonio Carlos Jobim, one of the founders of the Bossa Nova style (He, Joao Gilberto and Vinicius De Moraes) FYI, for those that don't speak Portuguese, in Brazil, 'Corte Real' would be pronounced 'Corche Hayow' whereas most people assume it's more like Spanish, 'cortay rayahl'. Not so. Not sure of the pronunciation in Portugal, though. I've heard, briefly people from Portugal Speak, but I love the 'sotaque' ( the accent ) of the 'Carioca' ( someone from Rio De Janeiro).
Wherever you are, it is now. The past exists only in memory. How does one travel to one's memory? If you travel somewhere that looks like your past, it is still now. See? It makes no sense. Memory makes time seem real. But, it's an illusion. There is no time. There is only the continuum of 'now', and even that, is dubious, the closer you scrutinize it. And, if time travel is mastered in the future, where are the time travelers who would have visited us in the present? And, if they visited us in our past, where are the memories and records of those events? Surely, at least one time traveler would have made him or herself known. It makes no sense. But, I'm no physicist .
Another way to look at it, A good one. In my hypothesis, since the future hasn't happened, hasn't been written yet, time travel has not yet come into existence. So no one from the future could come back in time to the past or present since the future doesn't exist. It is yet to be written. Only the here and now exist, the past existed, but the future is non-existent. It has happened yet, so no one or anything presently exists in the future. Which brings up another thought caused by you. Perhaps once the past has happened it too goes into non-existence. Ceases to exist as you put in your memory and in history books. So if true, time travel to what was would also be impossible as it ceased to exist once it happened. Thanks for the post. Which brings up another question, is time linear? Or is time like a big wheel and repeats itself?
I seriously doubt time travel. But, I can't accept your notions of memory and time here. The immediate result seems to be that there are HUGE numbers of "pasts" as no two people's memeories compare at all well. We know we can't even trust eye witnesses to important events. There really was ONE past. And, there are billions of people with different impressions of that past. There are also documents of all types, including recorded images that contradict the memories of individuals. There weren't billions of pasts.
I think you were giving credence to the memories of individuals as evidence of multiple pasts or of pasts not being real. Our capabilities in documentation suggest to me that there really is ONE past and it is the memory failures that are very human that lead to different "pasts". Maybe I didn't get what you mean. That could certainly happen! But I see no indication of multiple pasts or of pasts being unreal in some way.
No, I was simply stating that the past only exist in memory, i.e, the mind, which is to to say, the past does not exist, and, as such, there is no where that can be traveled to because the only place one can travel to is a place that exists. Therefore, time travel is a myth. But, I'm no physicist, and maybe I'm missing something.
