# A Meritable Veritable Time Paradox?

• B
So I stumbled upon this paradox and was wondering what cosmologists had to say about it. For the most part, I take an instrumental view of science. Of course, I accept all scientific histories and truisms as rational touchstone, though I also think we can never be too precocious about the fate of things. A century or so ago, Lord Kelvin commented on the physics of the era without foresight of quantum mechanics. And centuries before that, Aristotle took a teleological perspective of evolution, whereas we flank back on natural selection at the differential level of the gene today. So we can never be too precocious about nature's ethic, though it usually does happen that the quantitative theory of anything wins out. And inasmuch as string theory or other QFTs extrapolate the fate of the universe, I do not coincide them with the fate of things in general. Can physical law churn the ethics of social norms? Could we jot down all the variables behind our decisions on a finite list, Freudian and biological rhythms and all? Stuff like that.

All that aside, it occurred to me that if someone were conveniently placed 2000 or so light years away from Earth, they could possibly observe the Crucifixion. Maybe with a phantasmagorical lenses or maybe with something as simple as an optical lens. At the moment, we flourish a number of modes of historical investigation. Cliodynamics, numismatics, prosopography vs biography, historiography, studies of archaeological cultures, linguistic cultures, philology... Not to mention, we even make use of supplemental sciences such as carbon dating or dendrology when examining tree rings to get a rough date for the Minos eruption. So it occurred to me that if we had the above mentioned lens through time, we would definitely add it to the list.

Should time be sacred? Are our future selves farming our fates? What does our current theory of relativity and optics have to say about it?

weirdoguy

PeterDonis
Mentor
2019 Award
Where? Can you give a reference?

if someone were conveniently placed 2000 or so light years away from Earth, they could possibly observe the Crucifixion
In principle, yes, if they had a sufficiently powerful telescope. However, that someone could not just go there now. They would have to have been there already when the light rays from the Crucifixion arrived, which means they would have to have left Earth more than 2000 years ago in order to be 2000 light-years away from Earth in time to see those light rays (since they would have to travel slower than light).

Maybe with a phantasmagorical lenses
I don't know what these are.

if we had the above mentioned lens through time, we would definitely add it to the list
We can't. There is no way to go faster than light, so there is no way for us to send an observer out to "catch up" with light rays emitted from past events on Earth.

Ibix
Yes, someone two thousand light years away could in principle observe the crucifixion, although it would only be possible to see parts of it (or maybe all of it at a very steep angle) as the Earth turns and it would turn away from the viewer. Also, there'd be no particular reason for them to be interested in the execution of a preacher in a provincial Roman town, since they wouldn't have any way to know his followers would become what they are today. They would need an unbelievably large telescope, though, on the order of hundreds of thousands of kilometres in diameter at least.

This doesn't do us any good, though, since there's no way for us to build a telescope 2000 light years away without travelling there, which would take more than 2000 years. So you wouldn't even be in time to see your own departure, let alone things that happened millenia ago. Much easier to build cameras closer to home.

Ibix
I don't see what's paradoxical about this either, by the way. It's just the same as hearing thunder and knowing that the lightning discharge happened seconds earlier. It's just that you're imagining distances so large that even light takes a while to cross it.

In principle, yes, if they had a sufficiently powerful telescope...
Yes, someone two thousand light years away could in principle observe the crucifixion...
Well you know, what with worm holes and whatnot. Oh and a link for phantasmagoria and magic lanterns and etc.

Ibix
Well you know, what with worm holes and whatnot. Oh and a link for phantasmagoria and magic lanterns and etc.
Well, wormholes we can pass through remain under the heading of "there are only a couple of things that seem to be impossible stopping us from doing that". And even if we did that we'd still be faced with the challenge of building a mirror larger than most planets - and that's just to get the resolution. I've no idea if an image would be bright enough to see at that distance.

I don't see the relevance of magic lanterns (projectors, basically). You need a telescope.

DaveC426913
Gold Member
Well, wormholes we can pass through remain under the heading of "there are only a couple of things that seem to be impossible stopping us from doing that". And even if we did that we'd still be faced with the challenge of building a mirror larger than most planets - and that's just to get the resolution. I've no idea if an image would be bright enough to see at that distance.

I don't see the relevance of magic lanterns (projectors, basically). You need a telescope.
If we could build (or find) a stable wormhole, we wouldn't need to observe, we could go there. (I think. By moving them around, they can be used to make time machines, although I don't know if you can go back in time beyond when they're built.)

Also works if we can build a toroidal black hole. They can be used to travel in a timelike direction and emerge again.

But I like the phrase "there are only a couple of things that seem to be impossible stopping us from doing that".

BWV
Anyway why go back 2000 years? just go 1 light year away and train the telescope on the ticker display outside the NYSE, then you publish the prices and everyone gets rich!

phinds
Ibix
If we could build (or find) a stable wormhole, we wouldn't need to observe, we could go there.
I seem to recall a story about time travel tourism, which featured a trip to the time when Pilate release Barabas (or was it Wodewick...?). At some point the protagonists realise it's the Sabbath, all the Jews are at home, and the entire crowd is time travellers calling for Barabas' release because they knew that's what happened...
Anyway why go back 2000 years? just go 1 light year away and train the telescope on the ticker display outside the NYSE, then you publish the prices and everyone gets rich!
That would give you last year's prices, unless you invoke time travel, in which case you don't need to bother with the mirror.

PeterDonis
Mentor
2019 Award
unless you invoke time travel
Which is, of course, another one of those things that there seem to be only a couple of impossible things stopping us from doing.

Ibix
BWV
That would give you last year's prices, unless you invoke time travel, in which case you don't need to bother with the mirror.
I packed another fallacy in there as well

Ibix
DaveE
Gold Member

DaveE
Gold Member
How an engineer (me) reads this, the second time:

So I stumbled upon this paradox and was wondering what cosmologists had to say about it. For the most part, I take an instrumental view of science. Of course, I accept all scientific histories and truisms as rational touchstone, though I also think we can never be too precocious about the fate of things. A century or so ago, Lord Kelvin commented on the physics of the era without foresight of quantum mechanics. And centuries before that, Aristotle took a teleological perspective of evolution, whereas we flank back on natural selection at the differential level of the gene today. So we can never be too precocious about nature's ethic, though it usually does happen that the quantitative theory of anything wins out. And inasmuch as string theory or other QFTs extrapolate the fate of the universe, I do not coincide them with the fate of things in general. Can physical law churn the ethics of social norms? Could we jot down all the variables behind our decisions on a finite list, Freudian and biological rhythms and all? Stuff like that.

All that aside,
it occurred to me that if someone were conveniently placed 2000 or so light years away from Earth, they could possibly observe the Crucifixion. Maybe with a phantasmagorical lenses or maybe with something as simple as an optical lens. At the moment, we flourish a number of modes of historical investigation. Cliodynamics, numismatics, prosopography vs biography, historiography, studies of archaeological cultures, linguistic cultures, philology... Not to mention, we even make use of supplemental sciences such as carbon dating or dendrology when examining tree rings to get a rough date for the Minos eruption. So it occurred to me that if we had the above mentioned lens through time, we would definitely add it to the list.

Should time be sacred? Are our future selves farming our fates?
What does our current theory of relativity and optics have to say about it?

The answer, "not much". Since we don't know what "conveniently" means in this scenario. Also, the field of optics doesn't have much useful information about phantasmagorical lenses.

Staff Emeritus
2019 Award
I am puzzled by the suddent spate of threads that start from not understanding something to "it's a paradox I tells ya! A paradox!"

I am also wondering what this has to do with cosmology.

It's hard to extract meaning from the OP, with all those words in the way, but it seems to be saying in effect that if someone had thoughtfully put a giant mirror up 1000 light years away, one could use it to study 1st century earth. Sure.

DaveE
DaveC426913
Gold Member
...wondering what this has to do with cosmology.
Considering the OP asked five questions in the last two paragraphs, and all of them are philosophical in nature, I'd say this is binned wrong. But we don't have a Philosophy Forum...

Staff Emeritus
2019 Award
Philosophy is not flinging words against a wall hoping some will stick.

diogenesNY and weirdoguy
PeterDonis
Mentor
2019 Award
I'd say this is binned wrong
There is a physics question in the OP, so it isn't entirely philosophical. However, that physics question has been answered, so this thread is now closed.

phinds, weirdoguy and DaveE