Anyone Into Astronomy/Physics/Anything Related To Outer Space?

[haploid]

Don't think there is a thread about this yet, but I love this kind of stuff.

Discuss?

I'll start with an interesting little fact: The Sun accounts for about 99.8% of the matter in the Solar System. All of the other planets (Earth included, complete with all of it's passengers) and every comet and asteroid and speck of dust flying around the Sun adds up to be less than 1%.

[carlosreynolds]

Hmm. And most of that .2% is Jupiter and Saturn.

How about this: Unlike the planets, the Sun is great big sphere of hydrogen gas. Because of this, different parts of the Sun rotate at different speeds.They can track how fast the surface is rotating by tracking the movement of sunspots across the surface. Parts at the equator take 25 days to complete one rotation, while parts at the poles can take 36 days.

[Vampyrvargfesten]

1) Do White holes exist?

2) If so, was the Big Bang a white hole?

3) If an astronaut could somehow avoid the deadly X-rays and other shit, could he successfully travel through a supermassive black hole? Because the tidal forces would be minimal, what would be his fate?

[haploid]

As far as I know, black holes (past the event horizon) do not occupy "space" (3D) as we know it... Right? So how could the matter that he/she is made up of exist in such an area?

You raise very interesting questions.

[thirteengrand]

http://en.wikipedia.org/wiki/Quantum_eraser_experiment

careful guys, the photons are watching you

[Dijonnaise]

Most stars' masses are calculated in binary systems, from the orbits of the 2 stars, and the mass of single star systems is often deducted from these observations. It might sound dumb, butI'm always amazed at these kind of facts, of how astrophysics discoveries are made. It's so intricate.

I also read Stephen Hawking's book during the summer, I really enjoyed his theories on black holes, but by the end, with virtual realities talk and all that, I was completely lost.

[dopefresh]

If you were falling towards a black hole's gravity field, and were upright, your feet would be closer to the black hole than your head. As the force of gravity is stronger the closer you are to the source, the forces of gravity would be greater upon your feet than the forces that act upon your head. On Earth, this effect is negligible, as Earth's gravity field isn't strong enough to create noticeable differences. However, next to a black hole, the gravitational pull is so strong that your feet would fall towards the black hole faster than your head, effectively stretching your body vertically. This process is called 'spaghettification'. No shit.

More interesting stuff - we are not sure of the rate of expansion that the universe will follow in the future. One theory states that after a certain point of expansion has released, the forces of gravity will intervene and cause the universe to contract again to a point. Another suggests that the rate of expansion will slowly decrease until it reaches an equilibrium, and the universe can steadily remain in such a position indefinitely. The third, and in my opinion, most scary theory, is that the universe will never stop expanding - the spaces between particles will continue to expand indefinitely. As the universe expands, the distances between atomic particles will also increase, and it would eventually get to the point where the particles in an atom are so far apart that the nuclear strong force fails to hold them together. Basically, the universe would get so far spread out that atoms break up and the universe simply consists of redonkulously large amounts of desolate, spread out sub-atomic particles.

EDIT: most of you probably know about this, but astronomy picture of the day is a pretty cool website, check it out if you haven't seen it

[haploid]

But what happens if you go inside a black hole?! It's so strange to think about.

[dopefresh]

A black hole is not a hole, or a wormhole - this is a common misconception. It is just matter that is so densely compacted and has such a high gravitational force that it compresses matter to a point, where it has no dimensions. The escape velocity of an object is how fast you have to be travelling away from said object to escape it's gravitational field - on earth it is 11.2km/s (you have to be travelling at 11.2 km/s to take off from earth and enter space). The escape velocity of a black hole is higher than the speed of light - so photons do not have the speed to escape it's gravitational field, which explains why they appear black - no light can escape.

So, if you get sucked into a black hole, you don't really go anywhere. The matter that composes your body is just crushed to infinite compression, until it has no dimensions.

[Dijonnaise]

A black hole is not a hole, or a wormhole - this is a common misconception. It is just matter that is so densely compacted and has such a high gravitational force that it compresses matter to a point, where it has no dimensions. The escape velocity of an object is how fast you have to be travelling away from said object to escape it's gravitational field - on earth it is 11.2km/s (you have to be travelling at 11.2 km/s to take off from earth and enter space). The escape velocity of a black hole is higher than the speed of light - so photons do not have the speed to escape it's gravitational field, which explains why they appear black - no light can escape.

So, if you get sucked into a black hole, you don't really go anywhere. The matter that composes your body is just crushed to infinite compression, until it has no dimensions.

dot

an hypothesis that is also worth noting is the one suggesting that the dimensions of a black hole are indeed zero, thus making its mass infinite, bringing the black hole to the status of singularity. This would mean that at this point, the fabric of space-time is infinitely distorted (whatever that means to you). Hawking somewhat argues for and against this theory in his book

[haploid]

Wait, how can it have infinate mass if it has no dimensions? If there are no dimensions present, how can any mass exist?

(Not debating, just a question)

[dopefresh]

It doesn't have infinite mass, I don't know who said that but that's stupid, it would mean they'd have infinite gravity.

They have a fixed amount of mass corresponding to what has been sucked into the black hole. But because they don't have any dimensions, they have infinite density, and this is true of black holes of all masses.

[Vampyrvargfesten]

When I was in fourth grade, I read the Hitchhiker's Guide to the Galaxy

Thought this was interesting

For a mass as small as a human being, the gravitational radius is of the order of 10^-23 cm, much smaller than the nucleus of an atom

So if somehow a dude was compacted into smaller than an atomic nucleus, du would collapse into a black hole?

Mars Science Lab "Curiosity" is gonna b dope...

[dopefresh]

Yeah, but small black holes can't sustain themselves very well. So he'd probably explode after imploding.

At least, I think so. Haven't studied astrophysics in like a year.

[haploid]

Question: space-based arguments for 2012 true? (None of that Mayan bullshit) Personally, I've never been one to believe prophecy of any sort as it's all so vague you can place any meaning onto it that you wish but apparently we'll be passing through the galactic equator. I don't know how this is "bad" other than maybe there will be more space debris but I can't really see anything negative coming from it. People forget just how enormous the space between planets in the solar system is, let alone the space between objects in our area of the galaxy. If anyone has any astronomy-based facts about the 2012 argument, please provide them.

[thirteengrand]

Question: space-based arguments for 2012 true? (None of that Mayan bullshit) Personally, I've never been one to believe prophecy of any sort as it's all so vague you can place any meaning onto it that you wish but apparently we'll be passing through the galactic equator. I don't know how this is "bad" other than maybe there will be more space debris but I can't really see anything negative coming from it. People forget just how enormous the space between planets in the solar system is, let alone the space between objects in our area of the galaxy. If anyone has any astronomy-based facts about the 2012 argument, please provide them.

http://www.nasa.gov/topics/earth/features/2012.html

"Q: Could a phenomena occur where planets align in a way that impacts Earth?

A: There are no planetary alignments in the next few decades, Earth will not cross the galactic plane in 2012, and even if these alignments were to occur, their effects on the Earth would be negligible. Each December the Earth and sun align with the approximate center of the Milky Way Galaxy but that is an annual event of no consequence."

[haploid]

So why are all these pseudo-buddhist dickheads in my town claiming that the "stellar vibrations will tear apart the planet Earth"?

[Dijonnaise]

It doesn't have infinite mass, I don't know who said that but that's stupid, it would mean they'd have infinite gravity.

They have a fixed amount of mass corresponding to what has been sucked into the black hole. But because they don't have any dimensions, they have infinite density, and this is true of black holes of all masses.

oh, density, pardon me. I just wrote this off the top of my head.

As for your last statement, I'm pretty sure that's still an hypothesis, not fact. I clearly remember an argument that said quantum physics could possibly explain black holes in a different way that would show singularities do not exist in the hole.

Which would suck imo cause singularities sound cooler.

[dopefresh]

infinite mass = infinite matter = infinite energy = i dunno what, universe exploding or some shit

tru dat, we know fuck all

[AL-9000]

when i took the ACTs there was a reading section about neil degrasse tyson with questions at the end. i wrecked that part so hard from watching so much history channel/pbs

vioZf4TjoUI

[Vampyrvargfesten]

Hey guys this is pretty cool.

no LAWKI boo

what might be a potentially possible method to detect earth-sized rocky planets?

oh and this thread needs more pictures

[dopefresh]

The gravitational pull of an orbiting planet can cause a star to wobble slightly. By measuring these wobbles you can predict the existence of an extrasolar planet.

Also pretty recently I I think some method was made up where you can look at the actual planets using infra-red.

[haploid]

Damn that's really cool. But apparently the ocean on this new planet is extremely deep and extremely hot so chances of life are probably low :/. Wish we could visit, it would be incredible.

[thirteengrand]

i'm the prez of the science club at school (king of the nerds); currently in the process of planning a trip to see the one of the world's largest private relay scopes

will be wild to look through the device that the owner uses to observe gamma ray bursters in his free time

someday i'll spend my free time the same way

someday

[Vampyrvargfesten]

anyone been watching Through the Wormhole ?

posting it here because it doesn't belong in the "TV show thread" cesspool.

morgan freeman's voice + outer space =

[dfaus]

i wish i would have studied this stuff in college. i remember reading some ian thorpe book in highschool and finding it fascinating.