Outer Space

[dwarf]

Well there's no such thing as nothing. If there was a black space beyond everything in the universe then we can assign a colour or something to it and then it becomes something.

[Slaggis]

Well there's no such thing as nothing. If there was a black space beyond everything in the universe then we can assign a colour or something to it and then it becomes something.

 

No, that's not right. Just because as humans we can't fathom the idea of nothingness, that doesn't mean it can't or doesn't exist.

[dwarf]

No such thing as nothing for us simpletons then? I don't think there can be some different being that has such intelligence or clear-mindedness (this is BS I know) that they can envisage 'nothingness'. It doesn't exist for us, anything we see is something.

 

I don't know. There's probably some page that details all the philosophy behind it, like Wiki.

[Gizmo]

Well, I'm not at all trying to "quiz the Giz on phys". But I've learned that entropy is the level of "chaos" in a system, and that the entropy will never decrease, only increase. Like, for instance, if you drop an ice cube into a glass of water, the ice cube will eventually melt and become one with the water, thus making the system more chaotic. It will never re-materialise as an ice cube because that would lower the entropy of the system, which is impossible on this scale. But I've also read that on very large scales and very small scales (galactic and quantum scales, that is), drops in entropy are possible. The Big Bang is an example hereof.

 

My question is, then, would quantum physics allow for all air to suddenly manifest in the corner of a room? Or does that go against the law of thermodynamics, as it would lower the entropy of the combined system of the air and the room?

 

(I'm sorry if this is totally noob talk. I researched it myself on the Internet.)

 

I think you've misunderstood what entropy means. All the air molecules squeezing into the corners of the room is simply another state that the air molecules could be in. It's just as uncertain that they will all be in the corner as if they are spread out in a particular way. On a small scale, think of it like this: technically, the lottery numbers *might* be 1 2 3 4 5 6. Its ridiculously unlikey. But the chances of it happening are equal to the odds of any other number of numbers appearing - it's just a very unusual combination. The air all being spaced out in the middle is just like the numbers appearing random: 1, 13, 23, 35, 37, 44 appears just as random as 2, 17, 26, 31, 44, 45. But because they are both well spread out, you think of them as more likely to appear. In the same way, the odds of the air molecules being located in the exact places that they are at any given moment is ridiculously low, but the air is evenly distributed enough as to be basically the same. The only reason the air going into the corners is special is because it will cause something to happen - we will notice it. In the same way that nobody pays attention to the combination of lottery numbers - but I bet it would make the news if it was 1 2 3 4 5 6.

 

Isn't the universe both infinite and expanding at the same time?

 

The universe isn't infinite; that would cause a paradox with the night sky. If the universe extended endlessly filled with stars, its safe to say that every single part of the sky that a human eye could look at would eventually reach a star, and so light would be received. Every where in the sky would have a form of light being sent, and so the whole sky would be lit.

 

As for the universe expanding thing: I read about this, but it was as a sort of tangent to something else, and so didn't go into much detail and was bypassed quickly, so I can't remember too much about it.

 

One way I've considered thinking about it in the past is that the universe is expanding in that as time passes, more exists; the future is not certain until it has happened, etc. But this is wrong, and ties into aspects of time travel and particle behaviour which I could explain in depth but won't, because I'm lazy, and it's complicated enough that it will likely make my overactive brain confuse itself when I try to express it, and it will help nobody unless I take my time over it. If anybody wants, I can do, but nobody does, so whatever.

 

(re-reading that paragraph I see that my brain did fumble a bit even with explaining why I can't explain it, which is proof that I probably shouldn't)

 

I shall try and find the thing that I read, and if I do I'll post an explaination. I don't want to try and give my understanding of it now, because it may be inaccurate.

 

What is 'nothing' though?

The universe isn't expanding into anything as it's space itself expanding. For it to expand into something would imply space outside of space. So basically beyond this universe is....nothing.

No, that's not right. Just because as humans we can't fathom the idea of nothingness, that doesn't mean it can't or doesn't exist.

 

I'm afraid Haggis that Dwarf is closer to the current general consensus (which may be wrong also; we just can't be certain with these things because of your point that we as humans may be unable to truly understand. The best we can do is use analogies, which are usually wrong when we have a closer look. For example, when the electron cloud was first hypothesized, it was compared to the planets revolving around the sun, but thats quite an inaccurate analogy now that we know more)

 

The easiest way to think about it is like a balloon being blown up. The amount of material (mass) that the material is made of doesn't change, but it gets bigger. The universe is stretching in much the same way; in order to prove this theory I believe there are many measurements being made about the density of materials in the universe. I think they are finding results to support the theory, but I'm not certain on that. If this is the case, there are three possible outcomes ("The End of the Universe"). Either:

 

1) The universe will gradually stop expanding, and begin to collapse in on itself, eventually ending in a second big bang, only the other way around. (like a rubber band pulling itself back into place)

2) The universe will gradually stop expanding, and eventually expand at a rate of 0 after infinite time (basically, exponential decay, like the half life of a radioactive isotope)

3) The universe will expand forever.

 

Another analogy I was taught: it's like a rocket leaving the Earth. Either it doesn't have enough energy, slows to a stop, and then decelerates back to the surface; it has the precise energy required, and so reaches equilibrium, effectively hanging in the air; it has more than enough energy, exits the atmosphere and continues infinitely in a frictionless environment. The rate of the change in the density of the (of the of the of the)universe will tell us which of these is most likely, when we have enough data.

 

But don't get hung up on that balloon analogy, as it is inaccurate in many ways (not least the fact that the air has to come from an outside source, implying that mass (and therefore energy) is not being conserved, which is scientific blasphemy)

 

 

------------

 

This post ended up longer than intended. I hope at least one person reads it and understands it.

 

TLDR: Physics is complicated.

[weeyellowbloke]

The universe isn't infinite; that would cause a paradox with the night sky. If the universe extended endlessly filled with stars, its safe to say that every single part of the sky that a human eye could look at would eventually reach a star, and so light would be received. Every where in the sky would have a form of light being sent, and so the whole sky would be lit.

 

I thought that was because only a tiny fraction of the universe is actually visible to us. There are billions of galaxies and stars whose light will never ever reach us as they are moving away from us at beyond the speed of light. Although nothing can go beyond the speed of light literally they can relative to one another. I.e.

 

O<----------------------- ------------------------------>O

 

If the left hand and right hand planet were moving at the speed of light then the combined speed relative to each other would be twice the speed of light.

 

As for the concept of nothing, I don't know how you'd define nothing really. But I guess the universe is time and space, but anything beyond the universe cannot contain time or space otherwise it would be part of the universe. Ugh confusing.

[Dannyboy-the-Dane]

I think you've misunderstood what entropy means. All the air molecules squeezing into the corners of the room is simply another state that the air molecules could be in. It's just as uncertain that they will all be in the corner as if they are spread out in a particular way. On a small scale, think of it like this: technically, the lottery numbers *might* be 1 2 3 4 5 6. Its ridiculously unlikey. But the chances of it happening are equal to the odds of any other number of numbers appearing - it's just a very unusual combination. The air all being spaced out in the middle is just like the numbers appearing random: 1, 13, 23, 35, 37, 44 appears just as random as 2, 17, 26, 31, 44, 45. But because they are both well spread out, you think of them as more likely to appear. In the same way, the odds of the air molecules being located in the exact places that they are at any given moment is ridiculously low, but the air is evenly distributed enough as to be basically the same. The only reason the air going into the corners is special is because it will cause something to happen - we will notice it. In the same way that nobody pays attention to the combination of lottery numbers - but I bet it would make the news if it was 1 2 3 4 5 6.

Ah, yes, I've heard about this. So the entropy of the system wouldn't change if the air molecules suddenly ended up in one corner of the room?

 

This post ended up longer than intended. I hope at least one person reads it and understands it.

I did read it, and I think I understand it.

 

I can't comment much on the infinity discussion, but I just know my physics teacher told me something along the lines of the universe (or maybe it was space itself?) being both infinite and expanding, possibly exponentially, at the same time. I remember this in particular because I found it hard to understand that some infinities are bigger than others, and he gave me this analogy: Take every even number from 0 and up - there are an infinite number. Then take every natural number from 0 and up - there are also an infinite number, but there are also twice as many as there are even numbers, thus that infinite number is larger than the other.

[Gizmo]

I thought that was because only a tiny fraction of the universe is actually visible to us. There are billions of galaxies and stars whose light will never ever reach us as they are moving away from us at beyond the speed of light. Although nothing can go beyond the speed of light literally they can relative to one another. I.e.

 

O<----------------------- ------------------------------>O

 

If the left hand and right hand planet were moving at the speed of light then the combined speed relative to each other would be twice the speed of light.

 

As for the concept of nothing, I don't know how you'd define nothing really. But I guess the universe is time and space, but anything beyond the universe cannot contain time or space otherwise it would be part of the universe. Ugh confusing.

 

Light would still reach. Again, the best way to demonstrate is to think of it in an every day scale.

 

A-----------B

A is moving at 1m/s

B is moving at -1m/s (so they are moving apart at 2m/s)

 

A emits a particle towards B at 2m/s. Once this particle has been emitted, the motion of planet A will no longer affect the particle. So basically, its moving at 2m/s towards something thats moving away at 1m/s, so its essentially moving at 1m/s.

 

(The reason that A no longer affects the particle is that it is emitted in spite of A's momentum. Its like throwing something out of a car: yes, the momentum will slow it, but if you throw it with the right amount of forces, it will go out with whatever speed you want it too, and will no longer be affected. Since the photon has no mass, it is not concerned with momentum in the first place, and so will leave at the speed of light regardless)

 

So while it may be possible for them to be moving apart at over the speed of light, it's hugely unlikely and in the end doesnt really matter anyway. No star will be moving at anything like the speed of light, for one thing.

 

The next particle to be emitted will have a slightly larger distance to cover, and so will take slightly longer to get there. This means that the light will be visible, but intensity will be constantly reducing as less photons arrive per second. But this doesn't affect my hypothesis that in an infinite universe, there will be a star at every "pixel" of the night sky.

Edited July 29, 2009 by Gizmo

[Daft]

Not really sure how this photo was taken.

 

 

And another cool picture.

 

[Eenuh]

God I love space. Honestly these kind of space pictures fascinate me and I think they're just beautiful.

 

One of my dreams as a kid was to travel into space, and it's a dream I still cherish, even though I know I'll never get to do it. But maybe one day I'll find the money to buy a decent telescope at least so I can watch the night sky. =)

[Cube]

Exactly, that's the question. What would "nothing" look like? But then, as humans we can't actually imagine that because for us to imagine what nothing would look like, we're turning it into something more than nothing.

 

Nothing looks like black, due to the absence of light.

 

Not really sure how this photo was taken.

 

http://antwrp.gsfc.nasa.gov/apod/image/0907/devilstower_pacholka_big.jpg

 

Apparently, it's quite simple.

 

Pacholka said he employs simple techniques and does nothing extraordinary to get his shots. He uses a standard 50mm lens mounted on a tripod, and points a small flashlight on nearby desirable rocks and other land features he wants to stand out in the photo.

 

He allowed that his digital camera has a light-gathering power that is in some instances more than 50,000 times greater than a typical daylight camera setting. Pacholka runs his exposures anywhere from a few seconds to a minute.

[Daft]

Eenuh, you (and the pictures) have inspired me to look around for telescopes.

 

...They're probably amazingly expensive, aren't they?...

 

The one thing I really hate about living in a big city is that there are hardly any stars in the sky.

 

Apparently, it's quite simple.

 

Very little of that sounds simple.

[Razz]

Eenuh, you (and the pictures) have inspired me to look around for telescopes.

 

...They're probably amazingly expensive, aren't they?...

 

The one thing I really hate about living in a big city is that there are hardly any stars in the sky.

 

 

 

Very little of that sounds simple.

 

My friend is quite interested in astronomy and has a telescope, and as far as I know it wasn't at all that expensive. However, if you're in the middle of a city you're going to see next to nothing due to light pollution.

[dwarf]

What I love about the thought of using a telescope etc is that you may catch someone nobody else will see, and no-one will get the same view as the next person. I'm really tempted to get into it all, seeing as I'm always up late not doing a whole lot.

[Eenuh]

Eenuh, you (and the pictures) have inspired me to look around for telescopes.

 

...They're probably amazingly expensive, aren't they?...

 

The one thing I really hate about living in a big city is that there are hardly any stars in the sky.

 

 

 

Very little of that sounds simple.

 

Well of course the price will depend on the telescope, and how good it is. =P

To be honest I've never even dared to look at prices for a decent telescope. I just know there is an actual telescope shop in this city, and whenever I pass by it I tell myself that one day I'll go in there and look at buying one. X3

 

I don't really live in the city so I can see some stars, but it's usually too cloudy anyway. Though I remember laying outside at night quite a few times, trying to spot shooting stars. Should do that again soon really. =)

[Dannyboy-the-Dane]

I love those space and those images.[/cliché]

 

I think my interest in space was part of the reason why I loved Super Mario Galaxy so much.

[Hem]

 

Good video!

[MoogleViper]

Well of course the price will depend on the telescope, and how good it is. =P

To be honest I've never even dared to look at prices for a decent telescope. I just know there is an actual telescope shop in this city, and whenever I pass by it I tell myself that one day I'll go in there and look at buying one. X3

 

I don't really live in the city so I can see some stars, but it's usually too cloudy anyway. Though I remember laying outside at night quite a few times, trying to spot shooting stars. Should do that again soon really. =)

 

You can get a pretty decent telescope for £200 or less.

[Daft]

Another purddy picture!

 

 

When stars form, pandemonium reigns. A textbook case is the star forming region NGC 6559. Visible above are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt their birthplace. And then they explode. The resulting morass can be as beautiful as it is complex. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left is a naked open cluster of stars.

 

You can get a pretty decent telescope for £200 or less.

 

Have you got any recommendations? Or tips for what you should look for in a telescope?

[MoogleViper]

Have you got any recommendations? Or tips for what you should look for in a telescope?

 

A little bit, but it's been years since I was interested in telescopes. Might have a look into it again.

 

I do remember Orion being a good brand in that price range, and also Celestron.

 

And when you look at the magnification you have to look at the size of the lens as well.

 

And if you plan to take it to places then a smaller telescope is much more ideal. And they aren't necessarily worse than the longer ones. And even if it just stays in your bedroom then it takes up less room.

 

And don't buy any of the telescopes found in high street shops (unless you have an astronomy shop on your high street). It doesn't matter how good they claim to be they are usually shite. Buy from a dedicated astronomy shop instead.

 

Hope that helps.

[Daft]

Very interesting, thanks for that! I'll keep my eye out.

[mariosmentor]

Some believe that the outside force acting on our universe is actually a universe/dimension of anti-matter. An alternate reality/universe/dimension that acts in total balance with our own using the properties of anti-matter to sustain life instead of matter! This balance supposedly prevents the universe('s?) collapsing in on itself. Supposedly...

 

Remembering seeing a doc about it, some of my facts might be a bit shaky so I'd recommend looking it up yourselves. In fact the LHC ATLAS experiments are to determine the existence of alternate dimensions and the mysteries of Dark Matter as well as Dark Energy which makes up 70% of the universe.

 

The cool thing is if anti-matter and matter collide they are nullified so if their was a dimension of anti-matter and we collided it with ourselves it would mean the complete end of existence as we know it. Cool!

 

The scientist even theorize that the hidden dimensions(as much as 6 including the 3 we perceive height, width and depth) could be the unidentified forces that give gravity it's properties.

 

Check the LHC experiments here http://public.web.cern.ch/Public/Welcome.html

[stuwii]

Those picture that show the universe show light not in the human spectrum- I know it's not right but look at wii sensor bar through a camera

[Dannyboy-the-Dane]

Some believe that the outside force acting on our universe is actually a universe/dimension of anti-matter. An alternate reality/universe/dimension that acts in total balance with our own using the properties of anti-matter to sustain life instead of matter! This balance supposedly prevents the universe('s?) collapsing in on itself. Supposedly...

 

Remembering seeing a doc about it, some of my facts might be a bit shaky so I'd recommend looking it up yourselves. In fact the LHC ATLAS experiments are to determine the existence of alternate dimensions and the mysteries of Dark Matter as well as Dark Energy which makes up 70% of the universe.

 

The cool thing is if anti-matter and matter collide they are nullified so if their was a dimension of anti-matter and we collided it with ourselves it would mean the complete end of existence as we know it. Cool!

 

The scientist even theorize that the hidden dimensions(as much as 6 including the 3 we perceive height, width and depth) could be the unidentified forces that give gravity it's properties.

 

Check the LHC experiments here http://public.web.cern.ch/Public/Welcome.html

The M-theory suggests there are 11 dimensions, the 11th dimension having endless possibilities of alternate universes in it. I saw a documentary about it on YouTube. I can link to it, if people are interested.

[Shino]

The M-theory suggests there are 11 dimensions, the 11th dimension having endless possibilities of alternate universes in it. I saw a documentary about it on YouTube. I can link to it, if people are interested.

 

I am. I can't understand the string or M-theory but I sure like trying to, it's just so... incredible.

[Dannyboy-the-Dane]

I am. I can't understand the string or M-theory but I sure like trying to, it's just so... incredible.

I feel the same way. I'll try to find the videos, hang on ...

 

Here they are:

 

 

It's been a while since I last saw them.

Edited August 5, 2009 by Dannyboy-the-Dane