Last Day Of Junior Year 2023-01-07

[Dave]

https://wapsisquare.com/comic/last-day-of-junior-year/

[Opus the Poet]

Scarlet needs to put her sweater on, that blouse looks a mite... drafty.

[lake_wrangler]

Scarlet needs to put her sweater on, that blouse looks a mite... drafty.

Reminds me of the movie Down Periscope...

Lt. Comd. Dodge: Lt. Lake... you're... almost out of uniform. Now, either you have miscalculated your dress size, or there has been some foul play!

[Opus the Poet]

OK we have a setup, where is this arc going, last summer before Senior year? Sexy encounters? More ghost chasing? More eggnog with Iowa bourbon? Another encounter with the wisdom of Auntie Nudge? Or something totally out of left field? Discussion. Will Timothy survive the enlarged Scarlet?

[Alkarii]

Discussion. Will Timothy survive the enlarged Scarlet?

He won't, but it's how he always wanted to go.

[Opus the Poet]

Just leaving this here:

[Opus the Poet]

Now the other question is can Pickle's girlfriend survive her?

[Storel]

I can't remember -- who is Pickle's girlfriend?

[Dave]

I can't remember -- who is Pickle's girlfriend?

Shawna, the Pixie.

[Opus the Poet]

OK what is that sign behind them? It's either in Russian or some other Cyrillic alphabet language, or maybe it's a reflection of the sign for the Paranormal club (because of the ghost).

[Leak]

OK what is that sign behind them? It's either in Russian or some other Cyrillic alphabet language, or maybe it's a reflection of the sign for the Paranormal club (because of the ghost).

I'm 99,9% sure it's the sign for the paranormal club, just mirrored because we're looking at it through the window in the door it's taped to...

[lake_wrangler]

OK what is that sign behind them? It's either in Russian or some other Cyrillic alphabet language, or maybe it's a reflection of the sign for the Paranormal club (because of the ghost).

I'm 99,9% sure it's the sign for the paranormal club, just mirrored because we're looking at it through the window in the door it's taped to...

Confirmation found here, as I was looking for something else...

https://wapsisquare.com/comic/different-directions/

[Opus the Poet]

OK what is that sign behind them? It's either in Russian or some other Cyrillic alphabet language, or maybe it's a reflection of the sign for the Paranormal club (because of the ghost).

I'm 99,9% sure it's the sign for the paranormal club, just mirrored because we're looking at it through the window in the door it's taped to...

Confirmation found here, as I was looking for something else...

https://wapsisquare.com/comic/different-directions/

Now the question becomes was the sign printed on a transparent sheet that we can see the printing on the other side?

[lake_wrangler]

Now the question becomes was the sign printed on a transparent sheet that we can see the printing on the other side?

I remember a movie in French (or, at least, I watched it in French), made at least some 40 years ago or so, where scientists discovered that there was a planet orbiting the sun, on the same orbit as the earth, in a position exactly diametrically opposed as earth's position. Plans were made to send a rocket to explore. Much to everyone's surprise, said rocket landed back on Earth. People considered the mission a failure.

Once home, the astronaut happened to go to the bathroom at some point, and noticed that he could read the label of the after-shave bottle in the mirror...

[lake_wrangler]

Apparently, I got some details wrong... It was an unnamed cologne, not after-shave...

https://en.wikipedia.org/wiki/Doppelg%C ... 1969_film)

(I was right about the movie being at least 40 years old, but it was definitely not made in French...)

Here's the IMDB page for it.


And I had completely forgotten about the trial, and the astronaut being sent back...

Here's the trailer on YouTube:


Here's a short documentary about the film:


And here's a video relating the story of an engineer in Britain who tried to "fix" an error he saw in the print of the movie...

[Typeminer]

I'm not an orbital mechanic, but the whole premise of a hidden planet on the opposite side of the sun is physically impossible, at least for a planet of equal mass. Resonance with the greater masses of the sun and the earth is what keeps small stuff parked at L1. A full-size planet's another condition entirely.

Never seen the movie, so no opinion on whether it's any fun.

[Warrl]

Resonance with the greater masses of the sun and the earth is what keeps small stuff parked at L1.

Actually, not quite.

I believe that the five Lagrange points are pretty-much-equal stable solutions to the three-body problem in orbital mechanics... but the solar system is not a three-body problem. (For the specific Lagrange points under discussion, the additional body of most interest is Jupiter, and Venus is probably next after that.)

In the N-body problem, L4 and L5 become depressions - gravity wells. Things in *almost* the correct position and orbit will fall into them, possibly even into orbit around them. In fact there are quite a number of asteroids orbiting the Sun-Jupiter L4 and L5 points, named after figures in the Trojan War - thus these points also being known as "Trojan Points." And a much smaller number of asteroids in the Sun-Earth L4 and L5 points.

(An extreme case: an object in sufficiently distant orbit around L4 will *also* orbit around L5. While staying fairly close to the orbital path of the #2 body in the system, and never passing the #2 body. Saturn, Jupiter, and Earth are known to have asteroids in the resulting "horseshoe orbits." Cruithne, the one associated with Earth, has an orbital period - as seen from Earth - of about 800 years, even though its orbit around the sun necessarily takes one year plus or minus some small change.)

L1 through L3, however, become tiny pinnacles. Things that aren't precisely in the right location and velocity tend to fall off them. Oh, and with the number of bodies in the solar system, I believe the points move around a tiny bit. (However, it's still a lot easier - you need less station-keeping - to stay on the straight line between Sun and Earth at these points than elsewhere.)

(On the other hand, station-keeping an Earth-size planet would take a LOT of reaction mass.)

L1 and L2, in the Sun-Earth view, contain only man-made probes. No asteroids. And L3... well, it's kind of hard to observe, being directly opposite us in solar orbit, but we're pretty sure there's nothing to speak of there.

[Dave]

Actually, not quite.

(...)
L1 through L3, however, become tiny pinnacles. Things that aren't precisely in the right location and velocity tend to fall off them. Oh, and with the number of bodies in the solar system, I believe the points move around a tiny bit. (However, it's still a lot easier - you need less station-keeping - to stay on the straight line between Sun and Earth at these points than elsewhere.)

More than a bit.

L3 is perfectly stable, only for a perfect three-body solution (e.g. Sun, and two Earths of identical mass, traveling in exactly opposite positions in a perfectly circular orbit, with no other objects present in the Universe). It's hard to find such perfect solutions - heck, I can't even find a physicist's spherical chicken when I want to cook one properly.

For anything less ideal than that, L3 is a "quasi-stable" solution. As you note, anything which perturbs one of the Earths out of exact opposition with the other will push the perturbed object into an orbit which oscillates around L3.

Things become really complicated (and eventually chaotic) when you add the gravitational influence of the other planets. For example, there are parts of the year when Venus is closer to Earth than the anti-Earth would be, and thus has more gravitational effect on Earth's orbit. Jupiter's gravity is a big factor, as well.

So, eventually, anti-Earth would peek out from "behind the sun" into view. Even if it didn't, its presence would have been detected a long time ago through its effect on the orbits of Earth, Mars, and Venus.

L1 though L3 can potentially be interesting places to hang a research satellite, or (as some have suggested) a fuel depot, as the station-keeping requirements are quite modest compared to other orbits. (Flash back to Maude, tossing the coin she'd just received as a gift from Harold, into the river. He looked horrified. She smiled, and reassured him "I'll always know just where it is.")

(On the other hand, station-keeping an Earth-size planet would take a LOT of reaction mass.)

Oh my, yes. Consider how much energy we have to expend, using chemical rockets, in order to loft a kilogram of mass into low-Earth orbit, and how much more it takes to get it to reach escape velocity. The mass-and-energy efficiency is awful.

A super-civilization with the ability to tap into vaccum energy (if that's even possible) and access to a reactionless "space drive" (likewise) might be able to pull it off for a while, but anything short of that seems infeasible. And, in the end, motivation would probably be lacking... like the coffee-house term for a tall decaf non-fat latte (a "Why Bother").

Also, the impact of an "oops!" could make for a very impressive display... from a safe distance... a few light-months, perhaps.

[Opus the Poet]

We've got the setup down, but what about the summer before senior year? sexy interactions? Yet another ghost hunt? With more bourbon from Iowa, please. Another chance to hear Aunty Nudge's advice? Or perhaps something really unexpected? Discussion. Will Timothy make it through the expanded Scarlet?

That... sounds familiar.

[Dave]

That... sounds familiar.

Quite right... sorry, I missed seeing that it was a near-exact copy of your message when I approved it as a new-user posting.

Spammer or bot, posting through a server in Pakistan.

Account and posting deleted with extremely prejudice.