Anybody else amazed by the universe?

backwoods_lex · 09-07-08, 10:40

Ever since my childhood I've always been interested by space and all of the things in it. A few years ago I decided to read Stephen Hawking's book A Brief History of Time. Some of the concepts, theories, and facts absolutely blew my mind. Long story short, in keeping pace with daily life I've forgotten many of the interesting facts that I've learned in the past and figured I'd post some of those facts occasionally when revisiting the subject. Does anyone else share this interest?

Some interesting facts:

1. Time as we know it is affected by both speed and gravity. Time occurs at a different rate (though the difference is not noticeable) for someone sitting in a chair than it does for a person driving on an interstate in their car. Time also occurs at a different rate for someone high atop a mountain than it does for someone closer to the earth's surface and gravity.

2. The universe is filled with billions and billions of galaxies. Each galaxy holds billions and billions of stars.

3. The four forces of the universe (known as strong, weak, gravitational, and electromagnetic) were bonded together prior to the big bang creating a "superforce". Matter and energy were not separate. The big bang evolved from something that was infinitely hot and infinitely dense yet was smaller than the size of an atom.

I'm sure that it can be explained better by others. It's really difficult to wrap my mind around this stuff!

backwoods_lex · 09-07-08, 10:51

Oh, and some physicists believe that there are 11 dimensions

.

Mark77 · 09-07-08, 11:00

I read science magazines all the time so yes it is really interesting to me also. I just get so frustrated about how little we really know about space.

anarchistchiken · 09-07-08, 11:45

Quote:

Originally Posted by backwoods_lex

1. Time as we know it is affected by both speed and gravity. Time occurs at a different rate (though the difference is not noticeable) for someone sitting in a chair than it does for a person driving on an interstate in their car. Time also occurs at a different rate for someone high atop a mountain than it does for someone closer to the earth's surface and gravity.

Actually, the relativistic effect of time don't come into effect until you reach velocities that no human has even gotten close to experiencing.

However, if we ever develop technology to travel near the speed of light, month long trips on a ship could be dozens or even hundreds of years on earth. Physics is nuts.

Here's something to think about; The closest star to us (out of the billions and billions in our galaxy alone) is Alpha Centauri, about 4.4 light years (26 trillion miles). The fastest speed ever recorded by a manned craft was ~25,000 mph on the Apollo 11 mission, so that would be about a billion hours of flying (over 100,000 years, ten times longer than the entire span of human civilization. The closest galaxy, Andromeda, is 2.6 million light years away (59 billion travel years).

todd@bsaw · 09-08-08, 03:58

I, too, am a hobbyist physicist. I actually went to college as a physics major until I realized I hated calculus. I just wanted to do the theoretical stuff.

Hawkings books are great. Also check out The Elegant Universe by Brian Greene.

TortoiseAWD · 09-08-08, 01:09

"It's big and black and inky
And we are small and dinky
It's a big universe and we're not."

Something to give you some perspective about your place in the universe: HubbleSite - NewsCenter - Hubble's Deepest View of the Universe Unveils Bewildering Galaxies across Billions of Years (01/15/1996) - Release Images

Quote:

Several hundred never before seen galaxies are visible in this "deepest-ever" view of the universe, called the Hubble Deep Field (HDF), made with NASA's Hubble Space Telescope. Besides the classical spiral and elliptical shaped galaxies, there is a bewildering variety of other galaxy shapes and colors that are important clues to understanding the evolution of the universe. Some of the galaxies may have formed less that one billion years after the Big Bang.

Representing a narrow "keyhole" view all the way to the visible horizon of the universe, the HDF image covers a speck of sky 1/30th the diameter of the full Moon (about 25% of the entire HDF is shown here). (emphasis mine)This is so narrow, just a few foreground stars in our Milky Way galaxy are visible and are vastly outnumbered by the menagerie of far more distant galaxies, some nearly as faint as 30th magnitude, or nearly four billion times fainter than the limits of human vision. (The relatively bright object with diffraction spikes just left of center may be a 20th magnitude star.) Though the field is a very small sample of sky area it is considered representative of the typical distribution of galaxies in space because the universe, statistically, looks the same in all directions.

Bigpoppa3346 · 09-08-08, 01:22

Yeah, it's crazy (and almost uncomfortable) to think about, hard to wrap one's mind around. Sorta like the meaning of life, what happens to you when you die, etc.

It's just hard to perceive that space is infinite, we are so used to statistics and numbers, you can't put a number on how far the universe reaches.

TortoiseAWD · 09-08-08, 01:42

Quote:

Originally Posted by anarchistchiken

Actually, the relativistic effect of time don't come into effect until you reach velocities that no human has even gotten close to experiencing.

As I understand it, the time dilation effect is always present; however, it only becomes noticeable to you and me at significant portions of [i]c[/]. A sensitive enough clock, though, will show a difference for any two clocks in motion relative to one another, or when one is affected by a larger gravitational force than the other. For example, an atomic clock on the International Space Station runs slightly slower than an atomic clock of earth (approximately 0.0000000014% slower). GPS satellites must adjust for this effect, too . . . their on-board atomic clocks must be adjusted to account for their speed relative to earth's surface (about 7000 nanoseconds a day).

More info: relativitytimefly

Gobs more info with a Google search, too; that's just the first concise explanation I ran across.

Tort

TortoiseAWD · 09-08-08, 01:50

Quote:

Originally Posted by Bigpoppa3346

It's just hard to perceive that space is infinite, we are so used to statistics and numbers, you can't put a number on how far the universe reaches.

Problem is, we're not sure the universe *is* infinite, and that's just as difficult to wrap your head around. If the universe has a boundary, what's the boundary like? Inflation, dark matter, and (weirdest of all to me) dark energy make my head hurt.

NOVA Online | Runaway Universe | How Big is the Universe?

And then there's the other "ow, my head" branch of physics . . .

Tort
"It's turtles all the way down."

anarchistchiken · 09-08-08, 02:06

Quote:

Originally Posted by TortoiseAWD

As I understand it, the time dilation effect is always present; however, it only becomes noticeable to you and me at significant portions of [i]c[/]. A sensitive enough clock, though, will show a difference for any two clocks in motion relative to one another, or when one is affected by a larger gravitational force than the other. For example, an atomic clock on the International Space Station runs slightly slower than an atomic clock of earth (approximately 0.0000000014% slower). GPS satellites must adjust for this effect, too . . . their on-board atomic clocks must be adjusted to account for their speed relative to earth's surface (about 7000 nanoseconds a day).

More info: relativitytimefly

Gobs more info with a Google search, too; that's just the first concise explanation I ran across.

Tort

Fascinating, I guess I was wrong. Thanks. And I'm with you, quantum physics is just, like, woah. I want a wormhole machine.

Does anyone have an explanation as to why the earth and the other planets are relatively horizontal (orbitally) to each other?

stiffdogg06 · 09-08-08, 02:07

Quote:

Originally Posted by Bigpoppa3346

Yeah, it's crazy (and almost uncomfortable) to think about, hard to wrap one's mind around. Sorta like the meaning of life, what happens to you when you die, etc.

It's just hard to perceive that space is infinite, we are so used to statistics and numbers, you can't put a number on how far the universe reaches.

I agree. I look into the sky all the time thinking if there is other life like us and such. Just crazy to think about. I think about how everything works in uniform in space such as orbits and things LoL.

TortoiseAWD · 09-08-08, 02:12

Quote:

Originally Posted by anarchistchiken

Fascinating, I guess I was wrong. Thanks. And I'm with you, quantum physics is just, like, woah. I want a wormhole machine.

Does anyone have an explanation as to why the earth and the other planets are relatively horizontal (orbitally) to each other?

Not so much wrong; I'm just pedantic.

As for your question, ask, and Google provides: Why do most of the planets orbit the sun fairly on the same plane?

That also explains why Pluto's orbit isn't on the elliptic . . . IIRC, current theory is that it's just a particulary large asteroid that got caught in the sun's orbit sometime after the major planets formed.

Tort
(wishes Carl Sagan was still around)