Space: The BIG Picture

The Universe in Broad Strokes

1)Age of the universe: 13.7B years. (Age of the earth:4.5B)
2)Number of stars in the universe: 1BT
3)Number of galaxies in the universe: 100B
4)Number of stars in our galaxy (the Milky Way): 200-400B
5)Size of the (known) universe: 46.4B light years, in any direction. (sol: 186k mps)
6)Closest star to our sun (4.2 ly away, Proxima Centauri)
7)Number of Universes?

Let's look at the big picture. The Universe is 13.7B years old, since the Big Bang. There are a billion trillion stars in the known, observable universe (1BT). Let me say that again. A billion trillion. That's just the known universe. Space, by definition, goes on forever. There could be infinitely MORE "universes" (in our 3-D frame of reference). And I don't even know what the heck is going on with this infinite dimension stuff, with universes "on top of" other ones. This observable, known, 3-D universe has a 92-94B light year diameter, with us (earth) at the center. That's 46.4B light years in any direction, from earth. Light travels at 186,282.397 miles per second (in a vacuum). sol=speed of light. 186k mps, over 94B years. That's pretty inconceivably vast. The circumferance of the earth, at the equator, is only 24,902 miles. Light could circumnavigate the earth about 7.5 times in a single second.

Space doesn't have a boundary. We are not in a box, or a balloon, or whatever. I don't buy this nonsense about an "expanding" universe. Of course, the stars are getting further apart, so the phrase is as good a way of describing the phenomenon as any other. The moon is 1.5 light seconds away. The sun is 500 light seconds away, or 8.3 light minutes, or 92,955,820.5 miles out. People generally round that to 93M miles. That's an AU, or astronomical unit. (In case you haven't figured it out, my number shorthand is k,M,B,T for thousand, million, billion, trillion). Kant said that space and time are a priori concepts, i.e. they don't even exist. So, like, yeah, whatever.

Universe sounds like "one verse." The bible has around 31,273 verses in it. I wonder which verse the universe is. Maybe there are 31,273 universes. The koran has 6,666 verses. So 37,939 might be the total number of universes in existence. I'm just playin'.

If you ever wonder why you took trig, you might be surprised to know that the distance to the sun was calculated using measurements (from radar and atomic clocks) of distances and angles of the sun-venus-earth triangle.

Closest and Farthest: 4.2ly and 14Bly

The nearest known star to our sun, Proxima Centauri, is 4.2 light years away, as part of a triple star system, the other two (Rigil and Kentaurus) being 4.3 ly off. At the highest speed currently attained by a manned vehicle, relative to earth (24,790mph), it would take 32k years to reach it. In 9000 years, Barnard's star will be closer to us than that near Centaur. Using the nuclear pulse propulsion proposed in Project Longshot, it would only take 100 years, though. Once we got there, it would take 4.39 years for the data to reach earth.

The farthest known galaxy, reported in an article in '04, is a small one -only 2k ly across- and was spotted using the limits of our capability, aided by a natural cosmic gravitational lens and the Hubble telescope. It is 13B ly out. I'm sure there's a plus or minus as part of that (!). It was formed only 750M years after the Big Bang. We can tell it's old by the redshift (between 6.6 and 7.1), in which the reddish color is due to the absorption by matter in the universe between us and the galaxy, which suggests it is at a greater distance.

Observations of another distant galaxy reveal gas flowing at nearly 500k mph, "presumably accelerated by energy from supernova explosions going off like a string of firecrackers". Cool stuff.

Youngest and Oldest: Now and Long since perished.

New stars are still being formed. The oldest stars, the originals, composed of just H, He,and Li, are dead (there may have been another universe that collapsed before our Big Bang, though). Anna Frebel discovered "what probably formed as a second or third generation star" on the halo, or outer reaches, of our very own Milky Way, where the older stars lurk, using a different method than redshift because it was so close, looking for a telltale computer-model-predicted chemical signature. It has the exciting name of HE 1523-0901, and is dated at 13.2B years, barely 500M years after the Big Bang. Also, there's a 12.7B year old planet that was discovered, too.

Our solar system, the earth and sun included, formed between 4.5-5B years ago.

Gravity

Our solar system formed by gravity. I had a friend who once said, what if gravity is not a pull, but rather a push? I don't really know what to make of that, either. Gravity, as I understand it, is still not understood. Although I heard on tv 11-dimensional M theory might have something to say about it. I can't conceive of anything past 4 dimensions, with the fourth as time. I really don't know what these people are talking about. I wonder if they do, or if they just have elegant equations.

I read online that our probes throughout the solar system are experiencing anomalies in force upon them that our current understanding of physics cannot account for. Perhaps gravity needs to be rethought? Dark matter is a very grave concern, lol.

Anyway, most people that are into stars aren't astronomers- they watch Access Hollywood and Entertainment Tonite. I'm just a fuddy duddy. I want to be a fada daddy. VH1 said it costs between 184,320-269k to raise a child to the age of 18, in America. I still have that third world perspective, so I'm going to say it's less. My last name, Teshara, anagrams to 'he a star'. I want my next generation star. A sun would be nice. I want him or her bright, not dim, so he/she lives long and prospers, with golden years, like our 5B year old (or years young) sun.

Back to the brilliance. The sun has an estimated lifetime of 10 to the tenth years. That's 10B years. I.e. 10,000,000,000. It's 5B (4.57B, actually) years old already. It will become a red dwarf, eventually. Small stars, called red dwarfs, burn slowly and last tens to hundreds of billions of years. They simply become dimmer and dimmer, fading into black dwarfs. There are no black dwarfs yet, though, we think, because their lifespan is greater than the age of the universe.

The real black dwarfs, though, (maybe they're not dwarfs, they're pygmies), the Africans, specifically the Mbuti in the now Democratic Republic of the Congo, I read about in college in 'The Forest People', live a shorter lifespan. I read about the age difference in National Geographic, I think.

Galaxies:
Total in known universe: 100B (10M-1T stars each)
Ours (the Milky Way): 200-400B stars

It is estimated that there are probably more than 100B galaxies in the observable universe, with typical galaxies ranging from 10M stars to 1T stars. Our Milky Way galaxy has anywhere between 200-400B stars. It's around 80k light years from edge to edge. The sun is situated 25k light years from the galactic core. The bulge at the center is 10k light years thick, while at the rim, it's 3k l.y.'s thick. In perspective, that's 80 miles in diameter, and 2 mm's thick. The smaller stars in our galaxy are hard to spot; thus the uncertainty in the total number. Dark matter is thought to compose most of the galaxy's mass. The sun is made of plasma, or ionized gas. Our sun is an average star, a 4th magnitude, class M=4.83, main sequence, class G2V, 3rd generation, T Tauri Pop I star. Phew. That's a mouthful. Even Ra would be confused. So far, the sun has converted 100 earth-masses to energy through fusion. Our planet receives 1/2 of one billionth of the sun's Energy output. The surface temperature of the sun is 5780K and the core is 13,600,000K. The sun rotates faster in the core. Photons take an estimated 10k -170k years to get from the core to the surface (the photosphere) of the sun. The sun is brighter than 85% of the galaxy's stars. There are 100M G2's in the galaxy. The sun moves at a speed of 1AU every 8 days in it's orbit around the galactic center.

The earth's fate is tied to that of the sun's. In 5B years, the core will collapse, the temperature will increase, it will fuse He to C, and the sun's mass will extend out possibly to the current orbit of the earth or mars, as it becomes a red giant, although some research says as the sun loses mass, the planets will get further out and escape engulfment. In 900M years, the surface of the earth will be too hot for life as we know it. Earth's water will be boiled away, and the atmosphere will escape into space. We've got other problems to worry about though, for now.

I'm getting into this space stuff. It's fun. Binoculars, I am told, are a good way for beginners to start exploring the sky. I have two astronomy books: 'Exploring the night sky' by Terence Dickinson (winner of an '87 children's science book award) and 'Astronomy: A visual guide,' by Mark A. Garlick. Both are Firefly books. I have a telescope. I haven't yet checked out the rings of Saturn. Online, though, I've looked at the Helix Nebula, referred to as "the eye of God" and the Eagle Nebula (M16) in the constellation serpens. They are both quite beautiful.

Here's a powerful factoid on mortality and time: Stars, like fireflies, are born and die. They, like people, dim with age. Firefly. I loved that show (the 2002 Fox Joss Whedon tv series set in 2517, in space). I watched it at home with Sara. I heard there was going to be a movie... She likes River Tam (so do I). I think my favorite is Jayne Cobb, the mercenary. Jayne is a guy. I know a female Michael. Grave of the fireflies is a great movie.

Did you know there are more than 2k species of fireflies? And there are diurnal, non-luminescent species. They are found in marshes and wet, wooded areas where their larva can feed. They are state insects of Pennsylvania and Tennessee. They can synchronize their flashes in large groups, such as in SE Asia. Firefly is a subsidiary of Malaysia airlines. In Mayan mythology, they are associated with stars. Fireflies are also associated with cigar smoking. The light has two functions. In larva, it's a warning to predators (they are distasteful or toxic). In adults, it's used for mating. The ancient Chinese used them in lanterns. They are efficient energy users. 90% of the energy used to create their light is converted into actual light, (unlike, say, an incandescent light bulb, which converts only 10%). Take heed, science. We can learn from them.

Firefly is also a G.I. Joe character (a mercenary), a Batman enemy, a Uriah Heep album, and part of the title of that great sad animated anti-war film I mentioned. I was turned on to that movie with the book, 1001 movies to see before you die. So much to do, as I grow the database of my TOE. Busy, busy.