Astronomy/cosmology questions...

[Geo]

Looks a beautiful gadget. But quite expensive.
It does reminds me of a Kickstarter Project (i-Brix) where with similar technology they wanted to produce wirelessly Powered Lighting.
It was funded, test sets were sent out to reviewers, and some backers accually received their order, but the thing appearantly didn't come off the ground.

[Buster's Uncle]

Lori, what's going on with your space career these days?

---

And you're familiar with the season ender of Doctor Who, I assume, when 12 Dr. was trapped in the Panopitcon and something something TARDIS destroyed all the stars in the visible universe in 1066 or something, avec little whirlpool spirals faintly showing...  And the next season began with child Amy Pond in the new timeline w/ a starless sky, and people didn't believe there used to be stars in the sky up to a thousand years ago, naturally.  (TARDIS in the Sun's position w/ some 'splody effect exactly replacing the Sun.)

SO - that's a LOT of rubber comic book "science" to unwrap.  I can neatly rationalize all visible stars in the sky going out simultaneously from earth POV by postulating an anti-time effect traveling back at lightspeed, ignoring the instant impossible whirlpools.  How it puts out the stars, fusion and glow/heat, no.  The whirlpools visible at a minimum of 4.something LYs, never.  -And that's even if we were shown the southern hemisphere view, which would account that much for one.-  Where the mass of the Sun went, no.  Maybe it was still there, lit by the Tardis, but why no whirlpool?  Something something origin point, never mind the Sun.

I've been idly trying to work out this into something that makes ANY sense for YEARS.  Yes, I know.

Lori, how much of the universe, we're assuming a minimum case for naked-eye visibility for people on Earth's surface, had to destruct to achieve the minimum?

-The rest is less brain-straining stuff about alternate history and sailing-ship navigation but I'll post this much now.  I really want your thoughts.  -And everyone's who wants to play, of course.

[Lorizael]

I don't regularly watch Doctor Who, just catch bits from time to time, so I've never heard about this. But, uh, naked-eye visibility of stars doesn't even cover the whole galaxy. A smattering of very big, very nearby extragalactic objects are visible in very good conditions (Andromeda, the Magellanic Clouds). So, say, you'd need to wipe out the Local Group.

[Buster's Uncle]

Answered, makes sense,  thanks.



I do wonder about how huge the handwave would have to be to have history unfold the same way since 1066.  Very huge, obviously, but I wonder about how much one could fudge the sea navigating by the position of the moon and planets w/ very good almanacs and such.

No, seriously; there ought to always be a few planets naked-eye visible in the night sky, and much easier to use for that w/o any stars.  We'd actually tend to know a lot more about the planets w/o all the stars making them hard to distinguish/ find, astronomy still developing for all the same reasons, QED..

[Buster's Uncle]

-But any Astronomy worth mentioning would make Amy's mom and teachers not believing in stars REALLY hard to handwave - and VERY hard to believe nobody invented telescopes in that timeline for, again, all the same reasons...

[Lorizael]

Without the fixed stars for reference, I think tracking planetary motion would probably be a lot harder. But as far as navigation, we can look to Polynesian wayfinding techniques that involved detailed records of ocean and wind currents and the migratory paths of birds and such. (A few years back I was working on a story set in a fantasy world with no stars or moon, so I looked bit into how navigation might work.)

[Buster's Uncle]

Great!  I didn't really expect your astronomy expertise to be that particularly helpful in this part of the fanwanking...

Since we're already assuming minimum of the universe destroyed for naked-eye visibility -and that's all it takes for ignorant people to not believe in stars, arguably- you could probably make out a star/galaxy or two w/ as little as a good sextant -and they could well have invented stronger/bigger ones for just that reason- and I think working out that really good almanac I mentioned makes sense for the same reason, I don't see why the Copernican planets -and the Moon in the night sky half the time- wouldn't work reasonably well for navigation.

What you say about the Polynesian stuff is also invoking something like almanacs to work, surely.

[Geo]

Great!  I didn't really expect your astronomy expertise to be that particularly helpful in this part of the fanwanking...

Since we're already assuming minimum of the universe destroyed for naked-eye visibility -and that's all it takes for ignorant people to not believe in stars, arguably- you could probably make out a star/galaxy or two w/ as little as a good sextant -and they could well have invented stronger/bigger ones for just that reason- and I think working out that really good almanac I mentioned makes sense for the same reason, I don't see why the Copernican planets -and the Moon in the night sky half the time- wouldn't work reasonably well for navigation.

What you say about the Polynesian stuff is also invoking something like almanacs to work, surely.

But even all the stars in the Local Bubble (except for the Sun of course) would be wiped out, would't the light of those obliterated stars still travel to Earth, and thus said stars still be visible until the extinction event progressed through space towards the Solar System? It would mean that the brighest stars in the Local Bubble (and there are a number of those, since at the edges there's star formation clouds and high-mass stars) would still be visible up to say 500-1000 years in the future.

[Buster's Uncle]

Billions of years for the Local Group, surely.

That's why I invoked an anti-time wave of stellar destruction radiating from the TARDIS in the sun, as it did, traveling back in time at lightspeed.  It's Dr. Who, man.

[Geo]

Billions of years for the Local Group, surely.

That's why I invoked an anti-time wave of stellar destruction radiating from the TARDIS in the sun, as it did, traveling back in time at lightspeed.  It's Dr. Who, man.

No no, the local bubble!