Is dark matter all it's cracked up to be?

cosmictalk · Mar 19, 2006

thats dudet to you <img src="/images/icons/wink.gif" /> I got the joke but I also wanted to use it as a point that I was trying to get a cross. seriously I guess I should of laughed LOL!

cosmictalk · Mar 19, 2006

(This means as space expands the rate of expansion would excellerate. Now if the rate of increase of the zero point energy field were to remain constant or even decrease space would act either to diminish or remain the same. It is a dynamic process) So are you trying to discribe the universe as a body in equilibrium?

bonzelite · Mar 19, 2006

universe cannot be flat. it exists in 3-D. another reason to doubt such a theory.

cosmictalk · Mar 19, 2006

(listen, you will refrain anymore from your tepid callousness in reference to myself, and others. Your insolence is gone on far too much here) Don't threaten me ever! and don't do that attempt on my computer again! ( and if it wasn't you for warning I have reported this incident) I do not need a bunch of numbers and degrees or cordenace sent to as a joke or not

rogers_buck · Mar 19, 2006

Good post.

Saiph · Mar 19, 2006

um...cosmologists don't mean "flat" in the literal sense. It comes from how a 2-d representation of spacetime appears to be. You've seen the gravity well diagrams I'm sure, and how they produce bowl shapes etc. Those diagrams represent in 2d what's happening in 3d, since the 3d version is very hard to represent. In a closed universe, that 2d diagram wraps around to make a sphere, in an open universe it curves out to make a hyperbola. In a flat universe, it does't curve. This gives three different ending's to the unvierse: Closed means that the universe is going to expand for a while. Starting froma pole, then reaching the thick middle of the sphere, then shrink again towards the other pole. Ending == big crunch. Open means it's going to expand...and keep expanding, but do so faster and faster. ending== big rip. Flat means it keeps expanding..but it continues to slow down, but never quite reversing. This is similar to an object having exactly escape velocity from the earth or other object. It'll forever slow down..but it'll never quite stop, and never come back. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Mar 19, 2006

um...cosmologists don't mean "flat" in the literal sense. It comes from how a 2-d representation of spacetime appears to be. You've seen the gravity well diagrams I'm sure, and how they produce bowl shapes etc. Those diagrams represent in 2d what's happening in 3d, since the 3d version is very hard to represent. In a closed universe, that 2d diagram wraps around to make a sphere, in an open universe it curves out to make a hyperbola. In a flat universe, it does't curve. yes, i've seen such diagrams before. and they are misleading. to call the universe flat, despite diagramatic representation, is misleading and does not describe the universe. the universe is actually not effectively flat. and should not be designated as such. as this misleads and misguides. moreover, these concepts are built upon mathematical/algebraic graphic models that do NOT represent reality as it unfolds. look outside. nothing is flat. cosmic space is not following literally a graphed wireframe planar expansion scenario. to continue referring to the cosmos as flat is misrepresentational.

CalliArcale · Mar 19, 2006

All right, folks, let's try to calm down now, okay? nova_explorer and CosmicTalk, it looks like it was just a misunderstanding over a joke. Let's move on. (BTW, CosmicTalk, it's great to hear there's another lady here. <img src="/images/icons/wink.gif" /> We are few in numbers, we geek women!) <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

kmarinas86 · Mar 19, 2006

Flat means it keeps expanding..but it continues to slow down LOL First they say the universe is flat. Then they say the universe is accelerating and not slowing down <img src="/images/icons/rolleyes.gif" />. Then the latest WMAP comes about saying that it might be slightly closed! Talk about a discordance!

CalliArcale · Mar 19, 2006

<blockquote>In reply to:<hr />yes, i've seen such diagrams before. and they are misleading.<hr /></blockquote> Only if you stop at the diagram and don't read what the diagram represents. It's not meant to be a literal representation. It's meant to express an idea that cannot be literally drawn in a way accessible to human perception. Our brains don't work in 4-D, so the diagram can't be drawn that way either. I've never felt misguided or misled about it; it always seemed pretty clear to me that it was an analogy. Maybe that's because I read "Flatland" at an early age, though. (Great book. Great science fiction too, and the social/political commentary is interesting too. It's not entirely outdated, even though we're not living under Victorian ideals anymore. So, it's like the best science fiction in that regard -- it speaks to something fundamental in the human experience. But I digress.) I mean, how would you draw a hypercube? Especially on this 2D screen? Heck, how do you draw a cube in a 2D space? The answer to that lies in a set of artistic rules that have been developed over centuries. Mainly the last six centuries. I don't want to drag us off into art history here, but it's worth mentioning that even a drawing of a cube is not literally true, and by the standards you have given for representations of warped space, would be misleading. Most representations will at least use the principle of vanishing point, but many will also use shading and atmospheric effects to represent distance and volume. These are tricks artists have developed for centuries to fool the methods your brain uses to judge distance. There is a painting that you might like, by the surrealist Rene Magritte. It fits well with what you've been saying. It's a photorealistic painting of a pipe. The caption is Ceci nes pas un pipe -- this is not a pipe. <img src="/images/icons/tongue.gif" /> I found a li <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

cosmictalk · Mar 19, 2006

I think of the universe kind of like I do when observing fire! Everything seems to appear like a reaction to everything around it battling for survival and adapting. Does flat , go with that? thanks for the clarification

Saiph · Mar 19, 2006

Kmar: Well that's the thing. You're either flat, or you're not. The fact that we can have studies that produce similar results, lead to such different answers shows how close we are. One study gives an answer that's slightly on the "closed" side of flat...meaning it'll slow and collapse. Another study gives a similar answer (within reasonable range of the other's error bars, if not overlapping) and leans towards open... This is because all the results bracket the required conditions for a "flat" universe. Is there uncertainty on this? YES! it's one of the prime areas of research in cosmology...what is the actual answer. The general consensus I'm hearing around the dept. is that WMAP is the best answer to date, as it is more accurate than all the other studies on the subject, put together. Bonze: The term for it arises from the standard graphical representation, and it can be misleading. However part of the education in the sciences is to recognize where various ideas apply, and where they break down. I.e. these misconceptions are recognized, pointed out, and corrected in the education, and in the work. <blockquote>In reply to:<hr />cosmic space is not following literally a graphed wireframe planar expansion scenario. <hr /></blockquote> Then you're generally missing what those graphs represent. They are gradients, often over time. Take the spherical representation. It doesn't actually mean that the universe is a sphere. It shows how it's expected to expand and contract over time. Here's the picture: You've got a sphere, with a pole on top and bottom. The vertical axis is time the horizontal axis (or plane really) is space, specifically how large it's going to be. The tangential slope of the sphere at any point is the expansion rate (hopefully it'll become clear what I mean). Start at the top pole: The tangential plane to the sphe <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

bonzelite · Mar 20, 2006

There is a painting that you might like, by the surrealist Rene Magritte. It fits well with what you've been saying. It's a photorealistic painting of a pipe. The caption is Ceci nes pas un pipe -- this is not a pipe. I found a link to it: click here. (I hope that link still goes to the same place; it's a store selling Magritte posters.) You might like a lot of his stuff. He did some very intriguing stuff with perspective and perception, deliberately fooling the eye. If you like M. C. Escher, you'd like Magritte -- the style is different, Calli, now you're talking in my language. nice. hmm. if only you knew.... you've somewhat figured out my tastes. i could digress at this point into one helluva discourse on what you just mentioned. but it would really go far from topic. but in a way, not really. art and science are one.

Saiph, i understand. great explanation <img src="/images/icons/wink.gif" />

Saiph · Mar 20, 2006

glad to be of service. Maybe I'll work that and some other material into a post about space-time, since what you've posted is a common complaint. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

nova_explored · Mar 20, 2006

this certainly is bizarre. no threat. And whatever 'attempt' on your computer, i have no clue what you are talking about. i'm sorry you think i'm investing time and energy into another from across the aether. i can't stand that kind of computer hacking, if that is what you are referring to. but now i have to decipher your meaning -"and if it wasn't you for warning I have reported this incident" what does this sentence mean? Honestly. Did i warn you and because of this you reported the incident? Is that what you are saying? numbers, degrees, coordinants? Uhm, yeah, sure. lol. i'm curious, but haven't the slightest clue. <div class="Discussion_UserSignature"> </div>

bonzelite · Mar 20, 2006

huh? ^^^what the...

cosmictalk · Mar 20, 2006

what does this sentence mean? Honestly. Did i warn you and because of this you reported the incident? Is that what you are saying? **it asked if I wanted to report this illigal activity and I said yes and sent it in** guess the numbers may have been what the computer language sees and had not been allow to down load. Thankfully no harm done! <img src="/images/icons/wink.gif" />

CalliArcale · Mar 20, 2006

Not to get too far off the topic of the thread, but are you using Internet Explorer by any chance? That sounds a lot like Microsoft's bug reporter. The newer versions (I know Office 2003 has it, but Office 2000 did not) of their software includes a little agent that will helpfully e-mail a report of roughly what you were doing (in computer terms; it won't transmit information about what you were typing at the time, but it will transmit technical details like which memory sectors were being used for the particular segment of the program; that can be useful for detecting bad memory allocation, which they'd want to fix in new versions of the software). It doesn't do anything to help you as the customer; it's just for Microsoft's benefit. Being a bit of an anti-Microsoft type, I usually say "no" when it asks if I want to submit the bug report. (MacOS has a similar agent now, and actually I usually say "no" to that one too, mainly because I'm usually in the middle of something, and also because I'm a little leery of programs that "phone home", even for helpful reasons like this. It's just me.) BTW, if you see the phrase "illegal operation", it does not mean that a law has been broken. In computerspeak, "illegal" means that a program has tried to do something that doesn't make sense. A good example would be furnishing nonsensical data as arguments to a function call. If the calling program doesn't know how to deal with the resulting error, you get a error message telling you that there has been an illegal operation. It's a generic error message. <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

cosmictalk · Mar 20, 2006

thanks for the tip! sounds like that was the problem. also sometimes I get another one that talks about flash8 error but I have that downloaded. any tips on that ? <img src="/images/icons/frown.gif" />

cosmictalk · Mar 20, 2006

to my question about finding things in outer space that can actually absorb radiation . I found out that the answer is yes. Asteroids have been found to possibly be very pores and can absorb radiation. <img src="/images/icons/smile.gif" />

cosmictalk · Mar 26, 2006

Magnetism isn't bringing energy out of copper when electricity is generated. Energy from an outside source, like falling water, or burning chemicals releasng heat, are used to move the magnet. The magnets motion by the wire causes the electrons to move, thus taking the energy from the magnet, and being put into the motion of the electrons. so you are saying that magnets hold energy and when they are moved near a copper wire the energy is transfered from the magnet? Yet I never read mentioned that magnets hold energy. Guess I will have to read up some more on those ideas. <img src="/images/icons/wink.gif" />

CalliArcale · Mar 27, 2006

About the flash8 error -- I'm afraid I'm not very good with those kinds of errors. Sounds like something to do with your flash plugin, but you've already checked that. *shrugs* If websites are working anyway, you can probably safely ignore it. <blockquote>In reply to:<hr />so you are saying that magnets hold energy and when they are moved near a copper wire the energy is transfered from the magnet? Yet I never read mentioned that magnets hold energy. Guess I will have to read up some more on those ideas. <hr /></blockquote> No, the magnet doesn't transfer energy to the wire. What happens is that the magnet causes the electrons in the wire to move -- and moving electrons are all that electricity is. <img src="/images/icons/wink.gif" /> A generator, like the alternator attached to your car's engine, is basically a device for converting kinetic energy into electrical energy. A gas engine is used to turn a drive shaft. That drive shaft causes a magnet to spin around inside of a tight coil of copper wires. This causes the electrons in the wire to physically move, nudged around by the rotating magnetic field, which gives you an electrical current in the wire. Interestingly, you can also build a device that does the exact opposite: converts electricity into kinetic energy. If you put an external current through the tightly coiled copper wires, you can make the magnet in the middle spin around. This can be used to turn a drive shaft. In short, that's how you build an electric motor. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

Saiph · Mar 28, 2006

lets take a hydro. plant. The falling water moves through a turbine, which catches the water and is sent spinning, like a water wheel. Here we've use the potential energy of the water created by the water being above sea level, and transfered that to kinetic (it's falling). This kinetic is transfered to the turbine. the turbine is used to spin a magnet...another transfer of kinetic energy. The spinning magnet sweeps the field through a coil of copper wire, this causes the magnet to be slowed down (via induction forces) losing kinetic energy. This also moves electric charges in the coil...so a transfer of kinetic from the magnet,to the electrons occurs here. This is what electricity is, a net movement of electrons. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

mikelawre · Apr 17, 2006

Dark matter doesn't have to be electrically neutral in its building blocks, only in its overall clumps. I reckon that normal matter is the symmetric isomers of quarks and leptons (so that they can stack and form stable arrangements), whilst the asymmetric isomers cannot stack, so have great difficulty interacting, except by charge (which would be electrically neutralised by other, oppositely charged, asymmeric isomers) and by gravity for the clumps. Mike

bonzelite · Apr 17, 2006

saiph, that was a very visually entertaining post. very nice.

Is dark matter all it's cracked up to be?

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