Other founders of the "Golden Age" of Sicience Fiction

[rkomar]

You're right, you're not going to convince me with the "We don't know everything, therefore anything is possible" argument. We have reasons for believing the things that we do, even if they don't cover everything in the universe. And, if you were honest, you would admit that you don't follow that philosophy you are espousing in your everyday life either. You don't know everything, so do you believe that anything goes? Do you go around prepared for things that fall up, for phone calls that arrive before the caller makes them, for leprechauns with pots of gold? You don't, and scientists don't either. I'll say it again: just because you don't know everything, it doesn't mean that you don't know anything.

[mbovenka]

Originally Posted by AnotherCat

An example is, if the current model of the universe's expansion is correct, that galaxies sufficiently far away from us are traveling at speeds greater than that of light. Furthermore, despite their speed being faster than that of light, we can still see some of them.

That's because space itself is expanding at FTL speeds. That is not prohibited by relativity (this is why the Alcubierre 'warp drive' isn't impossible right off the bat), just FTL movement through space is.

And we can only see them because they weren't yet being pushed apart at FTL speeds when the light we see now was sent.

[MikeB1972]

Originally Posted by rkomar

The assumption that if, no matter how hard you try, nothing you see ever goes faster than the speed of light, then that's the maximum. And that's still the case, over 100 years after Einstein came up with special relativity to describe what they saw before that. There are many ways we create stuff that gets up to or near the speed of light, without going over. Included in that are particles in accelerators, that just keep getting heavier as you add energy rather than go faster than the speed of light, in agreement with special relativity. The universe is a big place with all kinds of stupendously energetic processes taking place in it. If none of them produce anything that moves faster than the speed of light, you have to start thinking that that's the limit. It's not just a matter of no imagination.

Quantum Entanglement doesn't seem to care about the speed of light though, experiments are continuing with instantaneous communications.

This has been measured at distances proving it's effect is faster than light.

[fjtorres]

Interesting sidebar discussion.
Just the kind of thinking the "founders" of the Genre wanted to foster.

Btw, among the "impossibilities" bedeviling the physics establishment is the EM Drive and it's kin. Very unlikely to lead to a practical reactionless drive but there is some weird physics going on in those gadgets.

https://en.m.wikipedia.org/wiki/RF_r...avity_thruster

The whole thing strongly echoes this Lee Correy story:

https://www.goodreads.com/book/show/549128.Star_Driver

Fun one.

[Cinisajoy]

Originally Posted by HarryT

Both electricity and batteries were well known a couple of centuries ago: the first electric telegraph, for example, was invented in 1816. Hence my disagreement with your comment that a flashlight would have been "hard to imagine".

Didn't they have batteries as far back as the 9th century?

[AnotherCat]

Originally Posted by mbovenka

...And we can only see them because they weren't yet being pushed apart at FTL speeds when the light we see now was sent.

You need to leave the word "only" out because there is at least one other reason why photons emitted by galaxies far from us and travelling faster than (Edit: deleted "at" sub's "faster than") the speed of light can be seen.

As the photons travel towards us they eventually enter the region of spacetime where the expansion of the universe is less than c (expansion velocity being a function of distance from us) and so are then able to reach us and become visible.

All assuming current models are correct.

[AnotherCat]

Originally Posted by rkomar

You're right, you're not going to convince me with the "We don't know everything, therefore anything is possible" argument. We have reasons for believing the things that we do, even if they don't cover everything in the universe. And, if you were honest, you would admit that you don't follow that philosophy you are espousing in your everyday life either. You don't know everything, so do you believe that anything goes? Do you go around prepared for things that fall up, for phone calls that arrive before the caller makes them, for leprechauns with pots of gold? You don't, and scientists don't either. I'll say it again: just because you don't know everything, it doesn't mean that you don't know anything.

You seem to be extrapolating your argument light years away from anything I have said.

Furthermore you now accuse me of being dishonest .

[barryem]

Originally Posted by rkomar

How do you who think we could be wrong explain how these mistakes don't manifest themselves in what we see of the universe? Does the speed of light hold in all cases except in some few that conveniently explain some macguffins used in some sci-fi novels?

How can you be so sure that our mistakes don't manifest themselves? We might have failed to spot it, or we might have misinterpreted their manifestations. Or maybe we don't know where to look yet. Or maybe they don't manifest themselves.

The old joke "I can't think of anything I've ever forgotten" sort of applies here in an offhand way. How can we claim to know anything about what we don't know yet?

All we really know about faster than light travel is that we don't know how it could possibly be done. We have no reason to expect it to happen but we don't really know enough to say that it won't.

Barry

[barryem]

Originally Posted by HarryT

Both electricity and batteries were well known a couple of centuries ago: the first electric telegraph, for example, was invented in 1816. Hence my disagreement with your comment that a flashlight would have been "hard to imagine".

Okay so change what I said to 3 centuries ago. I was making an illustration. The time period doesn't matter.

Barry

[Cinisajoy]

Originally Posted by barryem

Okay so change what I said to 3 centuries ago. I was making an illustration. The time period doesn't matter.

Barry

Batteries were around in about 200BC.

[arjaybe]

There are no galaxies traveling faster than the speed of light.

[mbovenka]

Originally Posted by AnotherCat

As the photons travel towards us they eventually enter the region of spacetime where the expansion of the universe is less than c (expansion velocity being a function of distance from us) and so are then able to reach us and become visible

How would that work, precisely, when space is expanding FTL? Light would be unable to reach the 'non-FTL' regions. I stand by my 'only'. Any light that is sent when the source is being pushed away from us at FTL speeds by expanding spacetime will never reach us. Period.

[MikeB1972]

Originally Posted by Cinisajoy

Didn't they have batteries as far back as the 9th century?

Older than that
https://en.wikipedia.org/wiki/Baghdad_Battery

[Cinisajoy]

Originally Posted by MikeB1972

Older than that
https://en.wikipedia.org/wiki/Baghdad_Battery

See post #115 for the finally remembered post. Thanks for the link.

[AnotherCat]

Originally Posted by mbovenka

How would that work, precisely, when space is expanding FTL? Light would be unable to reach the 'non-FTL' regions. I stand by my 'only'. Any light that is sent when the source is being pushed away from us at FTL speeds by expanding spacetime will never reach us. Period.

You need to take your argument to the advanced cosmologists, not to me.

Unlike yourself I cannot claim to be one of the few in the world who have a thorough understanding of General Relativity and consequently of spacetime, but as it is a topic that interests me (and I have a physics background) I take my lead from them. I do have enough general understanding though to see the basics of their case and acceptance of the observations that support that. You, of course, are entitled to disagree with them.