Science

[trolls' bane]

Originally Posted by katya

"quantum froth" huh. Never heard of that. But I do have a hard time trying to get my head around the concept of infinite mass. Wait, suddenly I forgot what an event horizon is. Wasn`t it something to do with the trapped light? How about the thing about the two slit experiement and electrons being in two places at once- is that related to quantum physics? I remember reading an article about it, how small things can be in two places at once (even as big as a small dust particle???). I haven`t thought about this stuff for a long time. Really crazy though. Hard to imagine. Extra dimensions are hard to imagine.

I've heard of that dual electron theory, or whatever you call it. Wow, you apparently know more than I.
But black holes are not of infinite mass. That is impossible. In fact, just to contradict myself, I'll say something that my senior docent/co-worker at the Living Desert said. He's smart, and pointed out what I'd never thought of: that there is no such thing as infinite in a finite universe. Infinite mass would destroy the universe. And one has to wonder: If the Universe was a singularity once, how come black holes don't "explode" (or expand) and create a new universe? Because the Big Bang (ah, I love science for it's simple names that are so blatantly simple that simplicity itself looks complex!) was a different kind of singularity: it was a timelike singularity. There was no such thing as time before the Big Bang. There was nothing. In fact, there was so much of nothing, that words like place are rendered useless, and even words like nothing and useless can't exist, and existence itself is impossible. Even impossiblility is unheard of, and then again, you can't hear anything if there is nothing to hear and nothing to carry the waves and now laws of science to govern how sound is received. On the other hand, black holes are spacelike singularities.
Which brings me to something else: space is not nothingness. Space is empty, but it's not nothingness. Nothingness cannot be empty, because it's nothing. In fact, it's theorized that space is just a word used ot describe the universal gravitational field.
And one more thing. Many people mistakenly thing that the galaxies are moving away from each other as the universe gets "bigger". WRONG! The galaxies, though getting farther and farther apart, are in fact remaining completely stationary except to the extent of minor tidal, gravitational, and coriolis forces combined with some laws of physics such as inertia (as in galactic collisoins). They appear to be moving apart because space is expanding. It's just getting bigger. I have some trouble explaining this, but perhaps the word, space dilation, is best to describe it.
And one more thing, in a black hole event horizon, for a ship passing into it, each day for them is millions or billions of years to a distant observer. And to them, the universe outside is moving at a chaotic rate. Chances are, the universe would collapse onto you long before you ever reached the horizon. All in a days work, too.

[katya]

Maybe if I post I will be able so see TB`s post...

[trolls' bane]

Originally Posted by katya

Maybe if I post I will be able so see TB`s post...

Can you see it yet? If not, I'll start singing my song. It will take about three posts with the current post limit, and that's probably an underestimate.

[Lotesse]

Trolls' bane, that was a friggin' awesome post!!! I used to stay up nights pondering these very things. Have you ever read this book entitled "Black Holes and Time Warps," by some brilliant MIT professor or something? Can't recall the guy's name, but what a great book. Hawking's amazing, too. I'm sure YOU've read all Steven Hawking's stuff.

[katya]

Yeah, I see it now.

Hm... Ok ok. I`m not saying I think black holes are singularities. It`s really been too long. All I`ve been studying is language and a little math. Let me think about this all for a while and get back to you. Thanks for giving me inspiration though. ^_^

EDIT: Yeah Lotesse, I read "A Brief History of Time" (and I brought it with me) and other than that I have read my physics textbook (there was actually some pretty good stuff in it) and some stuff by (Sir?) Roger Penrose. Other than that I haven`t had time besides an article or TV program here and there.

[trolls' bane]

Originally Posted by katya

Yeah, I see it now.

Hm... Ok ok. I`m not saying I think black holes are singularities. It`s really been too long. All I`ve been studying is language and a little math. Let me think about this all for a while and get back to you. Thanks for giving me inspiration though. ^_^

EDIT: Yeah Lotesse, I read "A Brief History of Time" (and I brought it with me) and other than that I have read my physics textbook (there was actually some pretty good stuff in it) and some stuff by (Sir?) Roger Penrose. Other than that I haven`t had time besides an article or TV program here and there.

I never said you did, and if you did, you'd be correct. There's connections out there that all of our combined knowlege wouldn't be able to comprehend, including that nothingness, which I still imageine as "White" but white is something in itself.
Nope, sorry, I actually got all this from one book and several hours of searching wikipedia. I heard of A Brief History of Time and almost bought it, decided against it because I didn't think I'd understand it (and consequencially bought the book where it said all this from the bargain rack--wonder why it was there!). A good sciecne book, the one I keep mentioning, is The Astronomy Cafe (I bought it only because I thought teacup cafe-ers would get a kick with me reading that), and apparently it is only 365 questions (and wonderfully simple answers describing such complex phenomena!) based on a whole website full of them. This book though is probably best, because it summarizes the best questions. I've got to visit that site. Also, after every entry in the book, it gives you a series of numbers that somehow take you to similar questions on the website if you type them in somewhere.

[Lotesse]

Do you have the name of that website? I very much want to visit it.

[katya]

Ok then maybe I said "infinite mass" instead of "infinate curvature of space time" which is the definition of a singularity, according to the glossary in Brief History of Time. According to my electronic dictionary though, a singularity is an "extremely" small point in space that contains an "extremely" large amount of material, which does not obey the laws of nature, especially inside a black hole or at hte beginning of the universe. I said infinite mass, and then you said black holes don`t have infinite mass but *are* singularities.. And I got even more confused. But it`s ok. I think we`re more or less on the same page. What do *you* think a singularity is? The two definitions I have are completely different so...

[trolls' bane]

I'll check, Lotesse...Let me post this so I don't have all the threads in my "New Posts" section of my CP erased, 'cause it'll take me a while.

Well, I think a singularity is, well, basically like you said. Or a combination of the two. For example, a black hole with the mass of, say, Jupiter, would be about a meter (check for accuracy--might have been a klick), and one with, say, the mass of the sun would be the size of a city. One with the mass of Betelguese (and we both may live to see it go supernova! YAY! It will be midnight sun for many months! Too bad I won't get any of my own astronomy in in that time, but no guarentee it will happen because it's predicted "within the next million years or so.") would probably be about the size of a big city, like LA, or a small state. That's a lot of mass in a small space. But not infinite. My science teacher once said that if you took a spoonful of matter from a black hole, and placed it on Earth, it would fall through the ground and KEEP FALLING.
I should stop there, 'cause I confused myself. Let's leave it with my opening two sentences.

[trolls' bane]

Lotty, the website is www2.ari.net/home/odenwald/cafe.html.
Unfortuneately, the website doesn't work for me. Browser keeps "timing out."

[katya]

Well, when talking about black holes it is sort of speculation, but I think maybe they`re a bit more dense than that... Let`s see, something about a neutron star lingers on the edge of my memory. IIRC, a neutron star is a star that has collapsed? and the spaces in between the parts of the atoms have gone, and it`s just mostly made of neutrons (which take up a lot of the mass of an atom) without the "empty" spaces, hence the name? Well, I remember they were pretty damn dense themselves, and I would imagine a black hole would have to be much more so. IIRC a neutron star that was once a regular star (vague...) into about the size of 12 miles diameter. Oh yeah, it was in that other physics book I read and didn`t bring with me. Crap. Ok, I did a quick (very quick) google search and they say a neutron star that was once the size of our sun would be about the size of a city, with a radius of about 10 km. So anyway what I`m trying to say is that to be able to trap light, a black hole would have to be a lot more dense/massive, one would think.

I think of a singularity as infinite.

This is kinda random but I came across if it in quest to review 11th grade physics class. It`s Newton`s 1st law of motion. I thought it was cute.

[Lotesse]

Sorry 2 interrupt, but hey trolls' bane, is this the link? I found it by googling odenwald -

http://www.astronomycafe.net/index.html

[trolls' bane]

Originally Posted by katya

Well, when talking about black holes it is sort of speculation, but I think maybe they`re a bit more dense than that... Let`s see, something about a neutron star lingers on the edge of my memory. IIRC, a neutron star is a star that has collapsed? and the spaces in between the parts of the atoms have gone, and it`s just mostly made of neutrons (which take up a lot of the mass of an atom) without the "empty" spaces, hence the name? Well, I remember they were pretty damn dense themselves, and I would imagine a black hole would have to be much more so. IIRC a neutron star that was once a regular star (vague...) into about the size of 12 miles.. circumfrence? radius? diameter? I`m a little hazy on the details. Oh yeah, it was in that other physics book I read and didn`t bring with me. Crap. Ok, I did a quick (very quick) google search and they say a neutron star that was once the size of our sun would be about the size of a city, with a radius of about 10 km. So anyway what I`m trying to say is that to be able to trap light, a black hole would have to be a lot more dense/massive, one would think.

I think of a singularity as infinite.

This is kinda random but I came across if it in quest to review 11th grade physics class. It`s Newton`s 1st law of motion. I thought it was cute.

True, probably. But if it was infinite, a stellar companion might get sucked in. And looking at most stars observable, they are binary, trinary, etc. systems. Many known black holes are discovered by the activity of their stellar companion, because of the matter getting sucked off the still-stellar star. But the star itself isn't sucked in, and it's own mass can avoid it, somehow. And besides, anything with infinite mass, all of it's counterparts have to have the same amount of mass. But there are two types of black holes: stellar mass and supermass. PErhaps "singularity" is a totally off word to describe it.
Oh, thanks, Lotesse.

[katya]

Black holes are jerks.


Not to change the subject or anything, but what can you tell me about the 6 extra dimensions? Do you know anything what they`re supposed to be like?

[trolls' bane]

Originally Posted by katya

Black holes are jerks.


Not to change the subject or anything, but what can you tell me about the 6 extra dimensions? Do you know anything what they`re supposed to be like?

From everything I've read about them, there is no way to compare them to our four. To find out, turn into a quark, which I imagine is near impossible. I wish I could know. They're wierd and messed up, I know that for sure.

[katya]

Turn into a quark huh? Ok, I`m going shopping. For excersize. ?

Have you ever seen that movie "What the bleep do we know?"? I don`t really remember all that it was about but I think it was at least interesting.

[trolls' bane]

Originally Posted by katya

Turn into a quark huh? Ok, I`m going shopping. For excersize. ?

Have you ever seen that movie "What the bleep do we know?"? I don`t really remember all that it was about but I think it was at least interesting.

You're asking me if it's okay to go shopping? I guess so.
Never heard of it.

[trolls' bane]

I beleive that these two excerpts from Ask the Astronomer will be of help to explain what I wish to explain, the last few sentences in particular.

What is infinity?
Infinity is many things to many people. To mathematicians, it is something that is practically 'concrete' and the many different kinds of 'infinity' can be classified in terms or Cantor's Transfinite Numbers. There are countable and un-countable infinities, and who knows what other kinds in between.
To physicists and astronomers, there are no infinities in the physical world. Not even space and time itself need to be 'infinite' in the purely mathematical sense. Whenever 'infinity' appears as a prediction by a theory of the physical world, it is deemed a flaw, and must be eliminated. It is considered a signal that the particular theory has been extended beyond its domain of applicability. Newtonian mechanics had no problem with bodies attaining infinite velocity, or acting through space with infinite speed. These expectations led to falsifiable predictions and that is, in part, why we now have special and general relativity. In the few cases where general relativity predicts 'infinity' in the form of singularities, this is regarded as a defect in general relativity theory that will be healed when a fully quantum theory of gravity is developed.

[trolls' bane]

Here's my hand-picked set of interesting FAQs from Ask the Astronomer for today:

What is a cosmic string?
In some types of cosmological models, it is postulated that when the universe expanded and cooled, the underlying 'scalar' field which produced inflation when the universe was 10^-34 seconds old, crystallized into numerous topological defects. The simplest is the monopole defect, the next most complicated is the cosmic string. These strings are 1-dimensional lines of warped space-time along which the density is 'singular' or nearly so. They weigh 10^-5 grams for each segment that is 10^-33 centimeters long or so. They may be millions of light years long and thread through our space like spaghetti in a colander. Gravitational lens searches suggest that, if they exist at all, they are probably very rare because they should produce multiple images of background galaxies and quasars, and the ones we find are accounted for by the known distribution of galaxies.

What are quarks and gluons?
Quarks are the particles which protons and neutrons and other 'heavy' subnuclear particles are composed of. Quarks are held together by the exchange of gluons, whose collective effect is to produce the strong nuclear force in nature. There are 6 distinct types of quarks, and each quark comes in one of three different 'colors' just as electrons can be positive and negative charged. It is the 'color' which the gluons react with just as the electrostatic force depends on the + or - charge on the body. Physicists think that quarks may be the end of the line for fundamental particles, and their 6 types neatly balance the 6 types of light particles called leptons of which the electron and the neutrino are the most well known members.

Is light conducted by space, or does it travel through it?
Light has nothing to do with space. It is a property of the electromagnetic field when this field is undergoing changes. from its point of origin, this field radiates out into space in all directions. It is invisible, but can be felt by charged particles. When this field is changed, for instance by suddenly altering the position of its emitter, a kink develops in the field which propagates out into space at the speed of light. Under the right circumstances of acceleration, this kink becomes electromagnetic radiation - light. So space simply acts as a passive container for the electromagnetic field, which in turn is the 'medium' in which light exists.
If there is no electromagnetic field in space, there is no light either, as in the inside of a closed, shielded box. The maximum propagation speed is the speed of the expansion of the electromagnetic field in a perfect vacuum, which is 299,792.5 kilometers/sec.

What are the '10 dimensions' that physicists are always talking about?
The first four are the ones we all know and love: Three dimensions for space and one dimension for time.
The other 6 are called 'internal degrees of freedom' and are related to the number of fundamental symmetries present in the physical world at the quantum scale. The equations that physicists work with require these additional dimensions so that new symmetries can be defined that allow physicists to understand physical relationships between the various particle families. They think these are actual, real dimensions to the physical world, only that they are now 'compact' and have finite sizes unlike our 4 dimensions of space and time which seem almost to be infinite in size. Each point in 4 dimensional space-time has another 6 dimensions attached to it which 'particles and forces' can use as extra degrees of freedom to define themselves and how they will interact with each other. Do not confuse them with 'hyperspace' because the particles do not actually 'move' along these other dimensions. They are not 'spatial' dimensions, but are as unlike space and time as time is unlike space!

What kinds of connections are there between the laws of the microworld (atoms etc) and the structure of the universe?
There are many points of contact because they are all part of a single natural system that obeys a consistent set of laws so far as we can tell. Also, according to Big Bang cosmology, when the universe was far less than a microsecond old, the laws of physics that dictated the structure of the universe were, in fact, the quantum mechanical laws that now dictate the structure of the atomic world. The universe emerged from a state where it was so small that its size was comparable to that of an atom or less. Under these conditions, macrophysics became microphysics. We are only now beginning to see fully all of the ramifications of such a state.
For example, Big Bang theory was used to predict that there would be only three distinct families of neutrinos, a fact later confirmed at various high energy physics labs such as CERN and Fermilab where 'atom smashers' probe the innermost structure of matter. The NASA COBE satellite discovered blotches in the structure of the so-called cosmic microwave background radiation. These blotches, according to Big Bang cosmology, are the fingerprints left over in spacetime from a time when the universe was one trillion trillion trillionth of a second old, and represent quantum irregularities in a primordial quantum field which have been magnified to cosmic size following the expansion of the universe.
Big Bang cosmology demands that there be no more than three different types of neutrinos, and the laboratory measurements of atomic processes show that this is indeed the case for the accessible physics below an energy of 1,00 GeV.
There are many more of these connections between cosmic structure and quantum law that are fascinating to ponder, and give a richness to our universe that was unimaginable by any other modern theories of the universe.

Why was there a slight imbalance between matter and antimatter just after the Big Bang?
We don't really know for certain. In nuclear physics, we know that some kinds of particles decay with slightly more frequency into matter particles than anti-matter particles. The K meson for example. This 'symmetry breaking' was also present when the universe was young so that presumably from an initial symmetric state of matter and anti-matter particles, slightly more matter would have been produced in the decay products leading to a slight 1 part in 10 billion excess of matter over anti-matter. Once the annihilation process was complete, you wound up with 10 billion gamma ray photons for every matter quark. We don't know why this kind of symmetry breaking occurred, but like all the others, it just seems to be the way that nature prefers to work, in the same way that it prefers that the speed of light have the value that it does, etc etc.

Will the laws of physics change in the future?
We do not know, however, there have been some troubling speculations based on what we presume to have happened long ago during the Big Bang. When the universe was still less that 1 second old, it probably underwent several 'phase changes' or 'freezings' as the physical laws by which particles and forces act, changed. We can uncover some of this change in our accelerator labs at CERN, Stanford and Fermilab so we are pretty certain that it happened in a big way when the universe was starting out.
Some cosmologists have speculated that, in the future, the universe may undergo yet another 'phase change' as some new physical state begins to nucleate and form bubbles of a new phase within the space of our current universe. These bubbles will start smaller than an atom, and expand at the speed of light eventually after billions of years to merge with their neighbors. By that time there will be little left of the regions of space where our laws of physics work, except perhaps string-like regions of spacetime.
Now, the next round of changes MAY not be all that spectacular because there is not much energy left in the universe which already has a temperature only a few degrees above absolute zero. There is little wiggle room to shove a new energy state under this particular rug. The change might involve an almost imperceptible change in the law of gravity by a few percent, or a very weak new quantum effect. No one knows. But consider this. If ANY of the dozen or so fundamental constants were to change by less than 1 percent from their present values, life might be made impossible as atoms become slightly more well-bound in molecules for them to be broken apart in life-sustaining chemical reactions.
Don't loose any sleep over this, on the other hand, this could happen tomorrow, or a hundred billion years from now. I would still buckle my seat belt and stop smoking as precautions to far more likely kinds of death!

Is there empty space inside particles the same way there is inside atoms?
The 'empty space' within and near particles such as electrons and quarks is far more active and complex than in the lower-energy 'empty space' within the boundaries of atoms.
There is no such thing as 'empty space' anywhere in nature. There are only apparent 'voids' that SEEM not to contain matter or energy, but at the level of the quantum world, even 'empty' voids are teeming with activity as particles come and go; created out of quantum fluctuations in any of a variety of fields in nature. Heisenberg's Uncertainty Principle all but guarantees the existence of such a dynamic, physical vacuum. Physicists, moreover, have conducted many experiments where the effects of these ghostly, half-real particles can be seen clearly.
The level of activity that fills the physical vacuum is set by the energy at which the vacuum is 'observed'. Within an atom, much of the activity is carried by 'virtual photons' that mediate the electromagnetic force, and by the occasional electron-positron pairs that appear and vanish. At very high energies, and correspondingly small length scales, the vacuum fills up with the comings and goings of even more high energy particles; quarks-antiquarks, gluons-antigluons, muons-antimuons, and a whole host of other particles and their anti-matter twins. Within the nucleus of an atom, gluons and their anti- particles are everywhere, going about their business to keep the quarks bound into the nuclear 'quark-gluon plasma', portions of which we see as protons and neutrons.

Is there an Absolute Highest Temperature opposite to Absolute Zero?
This depends on what one thinks the 'Theory of Everything' looks like. If there is a steadily increasing ladder of more and more massive particles ad infinitum, then as Physicist Hagedorn showed in the late 1960's, the maximum achievable physical temperature in the universe may be as low as a few trillion degrees. What happens is that as the particle thermal energy increases, the energy goes into creating progressively more massive particles with low kinetic energy. Eventually, no matter how much energy you 'feed' into such a system, all that happens is that you generate more massive particles with a lower kinetic ( thermal) energy. In essence, this pair production of massive particles acts like a 'coolant' which regulates the physical temperature at a finite, and perhaps surprisingly low temperature.
If the so-called Standard Model is correct, then quarks are fundamental and do not sub-divide into still more massive particles. The thermal energy is then free to increase practically without limit until you eventually end up creating 'quantum black holes'. This happens at a temperature of 10^32 Kelvin; that's 1 followed by 32 zeros! Once you produce quantum black holes, you have reached what many theoreticians believe is the end of the road for physics as we know it. Here, spacetime itself dissolves into a witches brew of quantum worm holes, black holes, multi-dimensional super strings and twistors. Most theories of the early universe give this temperature as a true limiting temperature for physics in the universe.

[trolls' bane]

Ah! Beautiful! Who would have guessed that the concept behind general relativity would be so simple? Thanks again, Wiki!

Originally Posted by Wikipedia: General Relativity

The curvature of spacetime (caused by the presence of stress-energy) can be viewed intuitively in the following way. Placing a heavy object such as a bowling ball on a trampoline will produce a 'dent' in the trampoline. This is analogous to a large mass such as the Earth causing the local spacetime geometry to curve. This is represented by the image at the top of this article. The larger the mass, the bigger the amount of curvature. A relatively light object placed in the vicinity of the 'dent', such as a ping-pong ball, will accelerate towards the bowling ball in a manner governed by the 'dent'. Firing the ping-pong ball at just the right speed towards the 'dent' will result in the ping-pong ball 'orbiting' the bowling ball. This is analogous to the Moon orbiting the Earth, for example.

Similarly, in general relativity massive objects do not directly impart a force on other massive objects as hypothesized in Newton's action at a distance idea. Instead (in a manner analogous to the ping-pong ball's response to the bowling ball's dent rather than the bowling ball itself), other massive objects respond to how the first massive object curves spacetime.

Now the equations are another story!