As a layperson, time travel seems impossible to me. Prove me wrong!

There can't be civilizations "billions of years older than ours". That is not how the evolution of the universe works.

To see this, look into "Stellar Population". The earliest are "Population I", almost entirely hydrogen and helium. They were large, burned hot, and exploded into massive supernova that left behind the first heavier elements like carbon. This phase of the galaxy maturing was the longest, lasting until around a billion years ago. These stars took the elements like Oxygen and Nitrogen, and through more "stellar cooking" started to convert them into the heavier elements like Iron, Phosphorus, and the like.

Most stars are "population II", also known as "metal poor stars" simply lack the kinds of elements needed to create life at all. And their planets are more commonly gas giants around a small rocky core.

And the first population III stars (like our sun) are only around 7 billion years old (or sun is actually an early "pop 3 star" at 5 billion). So that only gives around 7 billion years for a star to be created, planets form, then one of those planets to become stable in the right location to allow for life in the first place, let alone intelligent life and a civilization to grow on it.

As we know from observations on our own planet, that is not much time at all. It took most of the life of our system to arrive at humans.

If the history of the universe is a single year (the "Big Bang" midnight New Year Eve), our sun formed on 9 September and our planet formed on 14 September. The first life on around 25 September. Oldest fossil algae, 9 October. 1 December is when oxygen began to be found in significant percentages in our atmosphere. The Trilobite dominated the planet on around 18 December. The K-T event was 28 December. On 29 December the first primates (barely more advanced than squirrels) evolved. Humans in the form of homo sapiens? Literally 1 second to midnight on 31 December.

And remember no life could have formed more than a billion or so years before on our planet, because that requires population III stars. To put that into the same scale, population III stars were just not possible until around the end of August. And we know that the universe is a very hostile place, even seeing comet collisions less than 30 years ago which would have been as bad or worse than the K-T event. Almost every hundred million years or so life on our planet was largely wiped out, and had to evolve all over again.

Your hypothetical would have to evolve in one of the absolute first pop 3 stars. From a large metal rich pop 2 supernova, that did not develop a black hole. Then exist in the perfect location, and never have an ELE. Just not possible.

 

I've wondered why these light sabers are so powerful up to a distance of 3' or so, and then they have absolutely no effect. Did the photons just stop?

If an object can emit such a powerful beam, I'd guess that all you would need to do is point it at an adversary. If the adversary can repulse that, then surely they can also repulse other "hits".

 

Because it was entirely fictional. Sadly, a lot of people have a serious issue with separating fantasy and reality.

Hell, for decades now the real "War Room" of the US President has been this:



Literally a large storage room in the basement of the White House.

However, people seem to believe that in reality it looks like this:







You can't reason logically with those who have no basis in reality.

 

Of course it's fiction, and I think people will agree with that when asked.

I'm just amazed at the idea the writers clearly had - the idea that this combination of stupendous weapons, the "force", and swordplay with "light sabers" would be such an attractive combination.

And, I totally agree with your last sentence.

 

Ours is not the only universe. Your exclusive logic is not absolute.

 

Two or three billion years is entirely possible.

Hundreds of millions is a gimme. Your point is trivial.

 

https://www.scientificamerican.com/...t stars did not,darkness to light come about?

QED

 

You have a lot of good points, but you’re overlooking a few things.

One is that you assume life as being similar to what we have here on Earth. You are correct that it is highly improbable for Earth-like life to form much less evolve that long ago. We are tn the right time and the right place for our form of life to evolve…but are we certain that we are the only sort of life that can exist? Yeah it’s a popular trop of Science Fiction, but we might well go out there some day and find that there’s a rock trying to sell us a fake Rolex or rent us his sister.

That said however, the concept of the billions of years old civilizations is a bit of a stretch often for artistic license. Millions of years is more likely and more plausible. Especially when you factor in the five massive extinction events the Earth has gone through. Had any of those not have happened, there could have been a civilization that’s millions of years old here on Earth now.

 

What kind of life could evolve that uses no elements higher on the periodic chart than hydrogen, nitrogen, oxygen, and helium?

A life that is composed entirely of gasses at temperatures found on our planet?

Sorry, going to call BS there. Even carbon was not produced in quantities until part way through the life of Pop II stars. Then you have to get much later to begin to see even heavier elements like iron or copper, which are capable of transferring oxygen as hemoglobin.

Even the most primitive forms of "life" needed elements that could only come from late pop II stars.

 

I don't believe anyone is making the assumption that life would be like Earth life. But, there are requirements in order to have any kind of life.

First life on Earth was 3.7B years ago. That is amazingly soon after the existence of our solar system. And, our solar system came relatively early, as I understand it. From there, the advance of life on Earth to today has required thousands of millions of years.

Let's be careful about the extinction events. They may well have been an advantage. For example, mammals may not have progressed as rapidly if the dinosaurs continued to prevail. Extinction events created space for explosions of evolution.

 

"Amazingly soon"? Yea, only a billion years or so, give or take a couple of hundred million years.

And we do not even know what the status of life was like on Earth before that, as the planet was destroyed around 4 billion years ago and then had to reform a second time.

We already know that once the conditions are met, life can evolve amazingly quickly. The only problem is having the exact conditions needed..

 

I wasn't disagreeing with you.

I think the point is that there still isn't a very large window for advanced civilizations.

We should keep looking. But, it certainly wouldn't shock me if we found no signs of life at least for a very long time.