Time travel

[MildredHubble]

Another oops....North Korea got to Mars first.

"For All Mankind"....quite a departure from Earth's timeline when it came to the space race.

Oh wow! That was tense! Are you trying to make me buy an apple TV subscription?! Lol! I kinda need to watch that series now!

 

[Judge]

Oh wow! That was tense! Are you trying to make me buy an apple TV subscription?! Lol! I kinda need to watch that series now!

It's on only in pieces on YouTube. But it was so weird when I watched the first piece, having to do with a nearly fatal moon landing. At the time this infuriated me, wondering why anyone would want to malign such history. Then I started to notice all the recognizable actors, and that this was a serious production. Took a while to understand that it was deliberately intended as an alternate universe and timeline relative to our Earth's history of the space race.

A weird concept...but I couldn't stop watching...lol. Too bad, much of anything Apple TV stays on Apple. So these bits and pieces are all they are likely to allow on YouTube. But there are quite a few of them. Watch the one about the first American moon landing. Yikes...

The Space Race was always very close to my family in the 60s, given a fellow Naval Academy Midshipman my father used to double-date with, who went on to become one of the first Mercury astronauts- Wally Schirra. A picture my father took while they were out boating. Circa 1944-45.

 

[AndyFBlues]

Unless there are scientific laws that are unknown us, time travel is not possible. It is highly likely that there is intelligent life elsewhere in the universe. Intelligent life would have the same difficulty traveling to Earth as we would have traveling to them; space is just too vast for such journeys to be realistic. Even if one could move at the speed of light, it would still take many lifetimes to travel to some of the more distant planets.

It's possible that somewhere in the universe there is a species so far more advanced than us that they could overcome the distance and travel to our planet. Of course if they are that smart, I doubt they'd want to.

 

[Misty Avich]

I don't think time travel can be physically possible. My husband says that smart phones seemed like science fiction back in the previous century, but we were working towards something like that, as technology was advancing even then, and also it's tangible.
Time travel is way too complicated. It is always the present. The past was once the present, and it is only accessible through memories, photos, videos and legacy. You can't physically travel back.
Unless you get on a plane and go to the US from the UK? Then you'd be travelling back in time, of like 10 hours?

 

[MildredHubble]

Unless there are scientific laws that are unknown us, time travel is not possible

I can absolutely guarantee you we barely know any scientific laws. The human race just barely got started figuring them out! We know basically nothing at this stage compared to what is likely knowable.

That doesn't mean we haven't figured out a hell of a lot, but we have just begun to scratch the surface when it comes to understanding the universe. We don't even have a complete model of gravity yet and time is definitely affected by gravity.

 

[Crossbreed]

The CGI was a bit uhm, clunky, but it shows that even at that stage they could fairly easily put the same person in the scene twice.

Before CGI, double exposure "twins" goes back to, at least, 1961's The Parent Trap.

trailer

~​

The Patty Duke Show used that effect on TV in 1963.

 

[Crossbreed]

Here is a "making of" video,...

The Parent Trap, 1961

 

[Outdated]

I've been travelling through time for nearly 60 years now at what seems like a fairly steady rate. I'm not looking forward to the sudden stop at the end though.

 

[Crossbreed]

I'm not looking forward to the sudden stop at the end though.

It is not a stop.
It is a cross-dimensional jump.

 

[AndyFBlues]

I can absolutely guarantee you we barely know any scientific laws. The human race just barely got started figuring them out! We know basically nothing at this stage compared to what is likely knowable.

I agree, there is a lot we don't know yet. Things like quantum entanglement and the time-space continuum are fascinating subjects. At this point, we barely understand what we don't understand

 

[tazz]

Unless you get on a plane and go to the US from the UK? Then you'd be travelling back in time, of like 10 hours?

Well, you're still travelling forward in time, just to a different location where they have their clocks set differently.

 

[RemyZee]

I don't know what to make of it all. There's so much we don't know yet, which is both scary and exciting. (1) I am of the idea that our senses are not calibrated to perceive certain frequencies of light and sound, and so there is a lot going on right in front of us that we are just not able to perceive. Sometimes you may view video online of small children or family pets perceiving an entity in a room or out in the yard, yet the camera and the adults are unable to perceive it. Infants and small children do have differences in their perception of light and sound. I've actually helped design medical equipment on this very concept, that is make it perceptively inaudible to a premature infant. (2) I have heard stories of people having "out of body experiences" shared amongst our healthcare team. Very accurate. The types of phenomenon that definitely challenges your understanding of this world and gives you pause. (3) "Ghosts", well, there's enough people over the years that have experienced this sort of phenomenon to give you pause. Too many case reports all over the world and throughout time. Again, obviously, something is going on here we don't understand. Are the theories of multiverses and dimensions just outside our own that, when specific conditions are met, they can cross over each other. Are these the "ghosts"? (4) From my understanding of time, time always moves forward. We don't have control over time. Time controls us.

Hypothetically, in some future age of understanding of multiverses and dimensions, one may be able to visit different timelines or dimensions, but for safety, the rule would be observe only and not interact, if that were even possible given the potential for the "butterfly effect". In other words, even if the technology were to exist for time travel, or even visit some other timeline, you would have to be virtually invisible and undetectable to that other timeline,...or else. Your simple presence could set off an alternate chain of events.

Yes, the idea being if someone were to go back in time it would change things, even on an infinitesimal bit; because there wouldn't be the same continuity of events.

 

[Dagan]

The new season of Loki is quite interesting, at least. It takes liberties but also presents questions regarding many previous theories, even Hawking's work.

 

[Cryptid]

The oddly predictable thing about discussions on time-travel is that they always veer off into fantasy, science-fiction, and the entertainment industry.

I guess factual science just isn't enough for some people.

 

[MildredHubble]

The oddly predictable thing about discussions on time-travel is that they always veer off into fantasy, science-fiction, and the entertainment industry.

I guess factual science just isn't enough for some people.

To be fair, I think most people's concept of time travel is influenced by movies. The old trope that you can't interact with yourself has a plausible sounding explanation in Back to The Future 2. But as I said earlier they simply weren't going to blow the film budget on small scenes that would have either looked pathetic if done on the cheap, or would have swallowed a huge chunk of the budget for a 2 minute scene. So come up with an "in universe" explanation and people will kinda adopt the idea because it kinda sounds reasonable.

The explanation given in Back to The Future is that the same matter can't occupy the same space. But in reality your future or past selves would be made of almost completely different matter.

We can't be sure that causal paradoxes exist, if the many worlds interpretation of quantum physics is correct then you could go back in time and change as much as you like and all you would do is trigger the creation of an alternate universe in which you made the changes but they don't cancel out you going back in time because that happened in a different universe.

We can certainly go forwards in time quicker if we built the technology. All we'd need is a space vehicle travelling as fast as possible, then double back and time dilation will occur and you will arrive back on earth hundreds of years after you set off.

Then we have things like closed time like curves. The creation of these would mean you could travel backwards and forwards in time. Professor Mallet is working on a device that uses this principle, he seems very convinced that it will allow information or warnings to travel back in time from the future.

The main issue with real time travel science is that it's not very sensible to dedicate much time to it's study as it generally can be detrimental to scientist's careers. So what we have left, in the main, is Hollywood science fiction.

 

[tazz]

The oddly predictable thing about discussions on time-travel is that they always veer off into fantasy, science-fiction, and the entertainment industry.

I guess factual science just isn't enough for some people.

It appears that there are some extremely smart people on this forum. But unless you're a career physicist doing research at the forefront of this stuff, it's impossible to have a meaningful conversation based on factual science.

In general, the gap between the understanding that the Nobel prize-type physicists have and what the rest of us have is so large it makes anything we can say pretty much science fiction from the outset.

The predictable thing about humans is that they will over-estimate what they know, and veer off into fantasy and science fiction without even realising it.

On a more positive note, this definitely seems like one of those areas of study where the phrase "standing on the shoulders of giants" would seem appropriate. My sense from a basic understanding of the principles and a little math is that we need far more information and experimentation before anyone could realistically make a career out of researching time travel itself. Our body of knowledge needs to expand in many different areas first. And eventually, some bright spark(s) will piece it all together and come up with an experiment that has a real chance of proving/disproving time travel. They'll win a Nobel prize for it, but it will be the accumulation of knowledge from so many different people that gets them there. Aspirational, fantastical visions such as a unifying model of classical and quantum physics, the search for the origins of the universe, wormholes and so on informs the direction of research in some way - but at it's heart, physics research is about incremental steps. And I feel like there are a whole lot of little steps we have yet to make before we can meaningfully have a conversation about time travel.

 

[tazz]

Remember folks: Just because we don't know everything does not mean that anything is possible. Keep an open mind, sure. But don't go spending any time trying to find out if the world actually is round.

 

[Judge]

Who is to say of the science of other worlds or dimensions we have yet to know about, let alone understand? Which may have their own laws of physics, independent of our own.

It seems rather ethnocentric and dismissive to assert that the physics of this world automatically default to all others that we don't even know about. As well the possibility of other dimensions which may be able to penetrate or overlap into our own without necessarily adhering to our laws of physics.

And in the event one recognizes such possibilities, how would they go about "proving" such things if the only metrics they have are those that work only relative to this dimension, and not necessarily others?

Logic dictates that there is more in play than what science can yet account for.

 

[Dagan]

There isn't much that we may want to fully trust beyond theories or the documented interviews with astrophysicists or even the many Bob Lazar videos and podcasts specifically, per time travel. That John Titar guy (I think I got the name correct) was a nut, apparently, so he's out of the mix. Outside of those few sources that "one wants to trust," it really just leaves fiction and entertainment for everyone to talk about (but those are prime areas where actual theories and some experiments were first born).

 

[lovely_darlingprettybaby]

I have been binge-watching Dr. Who. Anyone think time travel is possible?...... A. With the right tech? B. Possible in theory? C. No way--gimme a break. D. Take me to the times when people only eat pasta. E. One day it will be normal. F. I'm working on a machine right now.

No I do not think it as possible. I think maybe there could be wormholes in the universe no one could ever access like falling through a black hole but you would never access it because you would die straight away probably.
However it is fun to imagine, sometimes I hope and pray for a time machine to undo mistakes or miscalculations I have made.
Seems like everything is my fault when I have a lot of time alone to think, do not have often a great deal of insight days just melt into the next and have been through a lot of abuse in my life.
Though it is fun to think of going in a time machine where you could go into another time however I am not sure I would want to, you can also dress up and imagine though sixties, 70s and 80s would be cool. Just for the fashion, milkshakes and drive thrus and dance nights or like parking a car somewhere putting on a radio and laying on the hood of the car and looking at the stars or putting a blanket somewhere and having a picnic under stars.
I think it is cool but it would be a bit weird and scary as well.
Also like back to the future if you touch one thing you can change the fabric of time. So it can change for the worse so that is a scary prospect in itself. No one would want that amount of power