julius2

So, if I understand correctly, "7 pm on the corner of 5th Avenue and 24th Street in NYC" is a point in spacetime, that will never happen again?

It is interesting to see others delving with the fundamentals. Having read quite a few posts I still find it hard to grasp the concept of spacetime. Space is pretty obvious with the three dimensions of length, width and height. The concept of time I can "understand". E.g. The "time" it takes from one end of the road to the other. Or the "time" it takes to boil an egg. In other words you "feel" the time and thus have a concept for it. Or for clocks, it is the count of a pendulum swinging back and forth. I have faith in the concept of spacetime since the empirical evidence is consistent with the theory. And it is used to explain gravity (general relativity). Special relativity is consistent with GPS navigation system operation. So all good there. Combining space AND time is confusing however.

Yes, a very big problem. Who would want "floof" in 100 years.... The thing is what makes us think we have a future in the universe? I blame the science of film-making. Maybe not so much in the world today where the movies are a bit "watery". But the 1980s, where we fed ourselves all sorts of science fiction. As a planet we have to be careful we didn't build a "machine" to spark our own death! In other words were the movies one big psychology machine???

I like the innovative thinking. Does this affect spacetime?

True. It would not be a simple extrapolation. First, we would need to know what sort of environment we are dealing with. For a simple case, the other planet could just be a mining settlement. Earth using it to mine for precious metals / resources such as magnesium, iron ore, oil. But would this just prolong our existence on earth? What is the end goal? If we as a planetary species are imaging a Star Wars like scenario, exchemist made a good point. On all the planets (desert planet, ice planet, Yoda planet etc), humans were freely able to breath the atmosphere. With this reality check, Star Wars is not believable at all. Yes, I know it is "just" a movie.

Why? I guess we would need a planetary vote on it.... But everything we have developed could be "duplicated" on the new planet. The economies of scale would be enormous. For instance, mining. How long has it taken humanity to develop all the science (periodic table), mining methods. We had to have the renaissance before we had the industrial revolution, which allowed us to make the machinery to undertake deep sea drilling etc. Our financial systems could be extended. Not only would we have an earth banking system which we have now, but an interplanetary banking system - depending on what resources are available on the new planet etc.

I guess following this thread, brings to light that is not such a straight forward question. The nature of such an earth-like planet would have a great effect on what we as humans of this world would do with it. For instance, we would not want to contaminate the new planet with stuff from earth, or likewise we would not want to be contaminated by anything living from it's environment. I guess I didn't think this far ahead. I guess it would be "rewarding" for this world to find another planet capable of being developed. But it would not be half as much fun if we were forced to wear space-suits everywhere on the new planet. So I guess we should appreciate the "luxury" of being so well suited to our existing planet.

Contamination would be an important consideration. Who knows what kind of bacteria would exist on the planet. It would depend what kind of vegetation exists on the planet. If the environment was found to be harmful would we try to invent vaccines?

What if we found another earth-like world that we could get to. Obviously that hasn't happened yet and maybe lots of people haven't thought about it yet.. What would you envisage the first steps would be? Exploration I suspect would be top of the list? My point is over the last 2000 years we have developed this world to such an extent. It has been such a voyage of discovery. But if we find another habitable planet would it just be a transfer of knowledge?

Not really.

I did find some stuff on the internet about Bounce Cosmology: https://www.scientificamerican.com/article/the-universe-began-with-a-bang-not-a-bounce-new-studies-find/ My model does not follow the Bounce Cosmology entirely. My model says that a universe - ie planets and stars - form after a Big Bang. But the thing is that this is actually a "mashup" of times from before. Where the times are like vectors - rather than many spherical objects in it. To prove all of this is probably quite difficult because how do we see that far back. Especially since everything has been "mashed up" in the Big Bang. But can anyone think of any possible scenario where we ARE able to see that far back. Hint: think outside of the box.

No, I am building a theoretical model, with the help of your responses. In general, my idea is that science works upon testable assertions. Making experiments to confirm or deny any scientific theory. The question becomes how does one test my theoretical model?

So following on we might have U2 (s = 140), U3 (s = 80) and so on. The question becomes how do these universes come into existence? For our current universe we have done a lot of research and the most accepted explanation is due to a Big Bang which matches most to current empirical evidence. My proposal for universes in general is that they are a "mash up" of previous "times" with "times" yet to defined properly. So this agrees with current theory of the Big Bang for the current universe. So instead of one universe spawning multiple universes I propose that there is a period where there are many different "times". This may contain primitive life very different to what we know. Eventually as these "times" get old they collapse and there is an almighty squeeze and then a big explosion.

Okay, I am happy to support my proposals. Sorry it is taking some time. I will try to do something to eliminate the guesswork ! Unfortunately I am not familiar with any of the mathematical examples with regards to multiverses. My preference is to read about this from books rather than "skatty" sources on the internet. This way the arguments are more coherent ! Bounce cosmology is a new term for me. But it sounds interesting ! Are you able to outline the basic tenets, here in the forum? So if I can add some parameters to my model..... Let us have the set {U1, U2, U3, .........} where U1 - universe 1 in time, U2 - universe 2 in time....... So by having a set this implies that we have multiple universes in time. I suppose for completeness we can call our current universe U0 or just plain U ! Now, what I want to address in my model for time is: - the varying sizes of these universes - so what are the sizes of {U1, U2, U3.....} My proposal is that each of the universes would be of varying size. Given the randomness of our own universe, you would not expect {U1, U2, U3.....} to be exactly the same. So adding a parameter for size (s) U1 (s = 100). might be universe U1 is 100 million light years across. And so on.

Thanks to all the posts on this forum to my posts. This is where I am up to so far.... The pretence is that there was time before the Big Bang. The question is what might this time look like? My proposal is that some of the time might look similar to what we see in the world today. So let's propose that there were earth worlds in the past. What is the model? Well, they would have had their own Big Bang. For the sake of argument let's argue that they there existed a "smaller" time than ours. So a smaller earth world and a smaller universe. Over time an earth world develops. Oceans form and plant life comes on to the planet. Then some form of reptilien life evolves. Reptilien possibly because it is more resilient in a more harsh environment. Then somehow other life forms evolve. And an ape like species evolves (like for us). And eventually humans come on to this earth world. They have a history, starting with tribes etc. Then eventually as society stabilises science develops and they invent engines, electricity etc. Then as time progresses they discover a type of time science. Overall their world dies, the stars in their universe die out and they go in to the Big Freeze. My proposal then is that we are living in a similar way but with a MUCH BIGGER world and universe. Will we go to in to the Big Freeze or will we discover something along the way that will alter our current trajectory in time?