fandomhigh | Astronomy 101, Moons and Planets -- Class 2 [9/13]

Week 2 -- September 13: The Sun

Syllabus | Class Roster

Handouts:
Starmaps: North | South | East | West | Overhead

Today Ellie is wearing a black t-shirt with "Astronomers like it Messier" on it, and They Might Be Giants song "Why Does the Sun Shine?" is playing.

"The Sun is by far the brightest object in the sky," Ellie began the lecture. "It's so bright that during the day its light drowns out virtually everything else in space. The Sun is so powerful that even from the Earth, its light can damage your eyesight. So never look at the Sun directly or through a telescope.

"Life on Earth is totally dependent on the the energy it receives from the Sun. This energy is produced when hydrogen atoms inside the Sun fuse to form helium. The Sun consumes four million tons of hydrogen every second. Even so, it's so vast that our star has enough fuel to keep it shining for another five billion years. The Sun's energy output is estimated to be 386 billion, billion megawatts. So in 15 minutes our Sun radiates as much energy as mankind consumes in all forms, during an entire year.

"The Sun has been given many names over the course of history. The Greeks named it 'Helios,' the origin of the adjective 'heliocentric' (meaning centred around the Sun). The Romans referred to the Sun as 'Sol,' which is where we get 'Solar System.' Until the Middle Ages it was generally assumed that the Sun orbited the Earth. In the 16th century, Nicholas Copernicus argued that it was the Earth that travelled around the Sun. However, he was not the first person to suggest this -- the Greek Philosopher Aristarchus beat him to it by nearly 2000 years. Copernicus's view of the Solar System wasn't accepted for many years until Newton formulated his laws of motion.

"The Sun is about 4.6 billion years old and is about halfway through its main-sequence evolution, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than 4 million tons of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation. In about 5 billion years, the Sun will evolve into a red giant and then a white dwarf, creating a planetary nebula in the process."

She went on to talk about the solar winds and solar flares and sunspots, then assigned the ~~handwavey~~ homework assignment.

[ooc: Thanks to

socksofcool for the song! SP is love for me today, since I'm in DC with my family and have no idea what my computer access will be.]

Flat | Top-Level Comments Only

Discuss, pass notes, whatever you wish.

Shawn actually looks like he might be concentrating during the lecture. Considering his short attention span when it comes to class that could be an illusion though.

Marie waved to Shawn when he happened to glance in her direction.

But really, she was taking notes. Honest.

Shawn smiled when he caught Marie's eye, and sent her a quiet, "Hey," in greeting. "How're you doing?"

"I'm dealing," Marie replied. "Getting used to things. How about you?"

"Well good..." Shawn shrugged, "I'm doing pretty okay. It's been a quiet week, which is great... Although I hear that around here it's a sign that we're about to be invaded or something. Calm before the storm and all."

"Well, I can't imagine anything being worse than those creepy floaty guys who stole our voices," Marie said.

Shawn nodded, "Yeah, Peter was telling me 'bout those on friday. Makes me pretty glad I was home for that part."

"Not being able to talk was very scary," Marie confirmed. "In comparison, the Jello dragons weren't that bad."

Re: Talk during class

justmisplaced.livejournal.com - 2006-09-13 16:00 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 16:04 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 17:00 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 17:16 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 17:38 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 17:41 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 20:32 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 20:35 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 22:21 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 22:24 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 22:28 (UTC) - Expand

untouchableskin.livejournal.com - 2006-09-13 22:30 (UTC) - Expand

justmisplaced.livejournal.com - 2006-09-13 23:23 (UTC) - Expand

Kaylee was taking notes. And possibly doodling.

Gwynn took a seat next to Kaylee and smiled as she took notes.

Kaylee smiled and waved at Gwynn.

Gwynn waved back. "Hi, Kaylee."

"Hi Gwynn. How are ya?"

"I'm doing well. You?"

"I'm mostly well, too," Kaylee replied.

notafairmaiden.livejournal.com - 2006-09-13 13:39 (UTC) - Expand

enginegirl.livejournal.com - 2006-09-13 14:00 (UTC) - Expand

Teddy was listening intently and barely looking up during his constant note-taking.

Or at least that's what it looked like. If one looked closer, they would notice the stick figure cartoon involving a tiny spaceship slowly moving toward a tiny sun, being drawn in the corner of his notebook.

Luke leaned over and grinned. "The wings need to be longer."

Teddy eyed the spaceship critically before responding. "It'd look all disproportional if i gave it longer wings."

Luke pursed his lips. "Maybe," he agreed. "Add more weapons to it and no one'll notice."

Teddy nodded and started adding random cannons on the sides of the previously peaceful spaceship.

"There, now it can fight other spaceships with tiny tiny wings."

"For peace and justice, of course," Luke pointed out, smiling.

Teddy raised his head up haughtily, "Are there any other reasons for such a noble ship to fight?"

He started drawing an enemy ship, identifiable as such by the angry eyebrows having been drawn on it. An artist, Teddy was not.

tatooine-doofus.livejournal.com - 2006-09-13 19:25 (UTC) - Expand

Parker's doodling suns, in between her notes. Coronas, stars, solar flares, in between facts and electrons and protons. She's half-paying attention, and half writing code for the website down the margin of the page.

Billy was taking notes, only instead of the actual age of the sun, he wrote really, REALLY old. He found himself distracted by Parker's artwork though.