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hippy4christ
Skeptic Friend
193 Posts |
 Posted - 07/21/2004 : 14:30:02 [Permalink]
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Hello all:
Thanks Filthy, you gave an accurate description of me.
Thanks for the info, where could I find detailed information on examples of incidences of dark matter's effects? Like 'today we saw that the orbit of planet X wobbled, we believe that it is due to dark matter because...
Hippy |
Faith is believing what you are told, whether it's by a priest or a scientist. A person's scientific beliefs are ones based on personal observation and experimentation.
Lists of Logical Fallacies |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 07/21/2004 : 17:10:29 [Permalink]
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As I understand it, it's when they look at the overall expansion of the universe, and the expected interaction between large bodies (like galaxies), that there is something like only 10% of the mass (visible) that is needed to explain things.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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furshur
SFN Regular
USA
1536 Posts |
Posted - 07/23/2004 : 05:59:10 [Permalink]
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Dave you said:
quote:
This kind of thing happens all the time. As far as I'm aware, nobody has ever seen what an actual electron looks like. The "tiny sphere" model works really well, but if we had microscopes with enough resolution, we might find that they actually look like tubby little leprechauns.
Actually, electrons don't 'look' like anything. That is to say an infinitely powerful microscope could not resolve an electron. If we were to shine light on a single electron the only thing that would happen would be that the electron would either increase in energy or reemitt single discrete photons. At best the only thing an optical microscope could see would be flashes of light comprised of a series of SINGLE photons.
I understand and agree with point you were making. I am not trying to 'nit pick' on this, I just find this point on electrons fascinating.
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If I knew then what I know now then I would know more now than I know. |
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Ricky
SFN Die Hard
USA
4907 Posts |
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furshur
SFN Regular
USA
1536 Posts |
Posted - 07/23/2004 : 08:52:11 [Permalink]
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I did not say you couldn't detect electrons, I said you could not SEE electrons. I still maintain there is nothing to SEE. They clearly exist, they have a charge, they have mass, spin and many other properties - they just cannot be seen. They are too small to have a "surface" that can be "seen" with EM radiation. It does not even matter if the EM radiations wave length is shorter than light the electrons still only interact with individual photons.
Cool stuff.
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If I knew then what I know now then I would know more now than I know. |
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chaloobi
SFN Regular
1620 Posts |
Posted - 07/23/2004 : 09:33:32 [Permalink]
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| I believe the wave length of visible light is longer than the diameter of an electron and so the electron cannot be seen. However, the electron microscope actually employs electron beams rather than light beams to 'illuminate' objects and reveive information from them that can be translated into images. Thus an electron microscope can get pictures of objects that visible light cannot. However, you can't use an electron microsocope to get pictures of electrons either. I think the whole concept of 'seeing' breaks down when you get that small anyway. Eyesight evolved to perceive the macro-world via reflected visible light. There is nothing analagous to that in the sub-atomic world. |
-Chaloobi
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Ricky
SFN Die Hard
USA
4907 Posts |
Posted - 07/23/2004 : 10:48:54 [Permalink]
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Sorry furshur, I mean seeing, not detecting. Bad word usage on my part.
And as for the electron microscopes, I believe there are two main kinds. One, a scanning electron microscope which gives back images of the surface of the object, and the other which chaloobi described where electrons are passed through the object and how many electrons make it through reveals the density, giving an image.
As for whether seeing must involve light or not, I think that borderlines on a low redefinition. Certainly seeing through a microscope and other tools that aid the eye with light goes under the category of seeing. But what about viruses? We know a lot of detail on the shapes and sizes of viruses, but they are too small to be seen with a light microscope (at least not the really big ones anyways, I think there are a very few that can be). I would definitely consider that seeing, as I know what they look like, and I think the same should apply for viewing electrons.
If we do find something that has a wave length that is smaller than the diameter of an electron, we will be able to "see" it. Probable? Maybe not. Possible? Yes. |
Why continue? Because we must. Because we have the call. Because it is nobler to fight for rationality without winning than to give up in the face of continued defeats. Because whatever true progress humanity makes is through the rationality of the occasional individual and because any one individual we may win for the cause may do more for humanity than a hundred thousand who hug their superstitions to their breast.
- Isaac Asimov |
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Dave W.
Info Junkie
USA
26020 Posts |
Posted - 07/23/2004 : 12:38:59 [Permalink]
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I know you didn't intend to nit-pick, furshur, but there are picked nits flying all over the thread now. 
Allow me to restate: right now, we've got no clue about the small-scale "surface" of an electron. Given the current sub-atomic models, we cannot know.
But let's assume - just for the sake of my point - that someday in the far future, an entirely different state of matter is discovered (which only interacts with normal matter kinetically and gravitationally - like "dark matter"), and one of these new particles - call it a probetron - is much smaller than an electron, and bounces off electrons like light off a mirror (in a macro sense). We might then be able to use probetrons to "map" the surface of electrons, much like a scanning electron microscope "maps" the surface of small things.
I mean technically, we can't "see" a lot of the stuff that electron microscopes reveal, either. We use the "maps" created as extensions of our sight, instead. If we can find the right particles - like my mythical probetrons - we should be able to "see" electrons just as easily.
Maybe they'll look like little bowls of ice cream.  |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Trish
SFN Addict
USA
2102 Posts |
Posted - 07/23/2004 : 18:20:18 [Permalink]
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quote:
Originally posted by Dude
Off the main topic, but somebody mentioned neutrinos....
There is some work being done now that has indicated neutrinos may be detectable by some rigid crystals.... and some work on creating a neutrino detector along these lines. (damned if I can find the journal where this work was mentioned.... no conclusive results, and nothing publised or peer-revied on the topic yet, but interesting none the less)
If this type of thing pans out... the possibilities for communications are pretty amazing.
A neutrino radio would not be limited by any kind of solid matter in the way, including the entire planet. Easy and very secure point-to-point communications systems, with no need for satellites.
When 1987A occured, they were able to capture neutrinos and show that they do have mass. I believe this occured in Italy or Vic was in Italy when 1987A kicked off. Victor Stenger is one of the physicists who worked on this project. http://www.phys.hawaii.edu/~jgl/nuosc_story.html Is a bit of info on the subject... |
...no one has ever found a 4.5 billion year old stone artifact (at the right geological stratum) with the words "Made by God."
No Sense of Obligation by Matt Young
"Say what you will about the sweet miracle of unquestioning faith. I consider the capacity for it terrifying and vile!"
Mother Night by Kurt Vonnegut, Jr.
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Commandant of the Marine Corps, 1943
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Skyhawk
New Member
33 Posts |
Posted - 07/25/2004 : 01:09:26 [Permalink]
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Remember, Heisenburg's Principle...you can only measure the velocity OR the position of an electron, never both. The very thought of 'bouncing' something off of an electron to be able to map it in some way would break the principle. An electron moving so fast and acts so unusual it has a wave-particle nature...wow...have fun trying to map that thing out. My best guess if it were possible to 'see' an electron myself would be just a cloud.
Anyways, I'm still too young in the scientific world (high school, grr) so if anybody can correct me that's cool. I love learning. Personally, I think the Heisenberg Principle will become obsolete at one point in time once we advance in our understandings to explain Weak Interaction phenomons (ie. The bogus idea of W and Z particles that seem to aquire greater mass and energy than the daughter particles and the sum of its energy are formed...but it still follows the Principle because its such a short instant..pfft). Also, I personally think the Probability concepts of 'nature rolling a dice' will become obsolete when we find better theories to improve upon what we know. I think the probabilty concepts are great and they work in our current model, but as our understanding and accuracy grows in our theories...the less probable nature becomes. Its like weather, our predictions are getting better as new technology and theories come into play though its still not perfect. I'd also take the time to say that our current equations and rules will be more simplified from its complexities once we do find these new theories. Its like we have 'few' equations with complexities to 'more' equations iwth more simpllicty. I think nature's rules are simple, they are just binded and unified in such a way that they seem complex in our own perception.
As Richard Feynman says that the universe is like watching a Chess game for the first time and trying to learn the rules of the game. I think htese rules will simplify in nature. Thats my 2 cent...please do give your point of view from waht I said :D. I know Im off topic...but hey! Its a discussion and you guys are cool.
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Skyhawk
New Member
33 Posts |
Posted - 07/25/2004 : 01:13:30 [Permalink]
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| O btw, I hope I'm alive when Unified Field Theory is discovered. Would be great to see this dark matter problem solved. |
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Ricky
SFN Die Hard
USA
4907 Posts |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 07/25/2004 : 16:02:43 [Permalink]
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quote:
Actually, electrons don't 'look' like anything.
That remains to be seen... (damn, that is a corny pun..)
Yeah, Newtonian physics break down on the subatomic scale, but a particle with mass should have some form of topology shouldn't it? I know the uncertainty principle says you can't measure position and spin at the same time... damn counterintuitive stuff... |
Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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Skyhawk
New Member
33 Posts |
Posted - 07/25/2004 : 22:21:16 [Permalink]
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I don't know, because of its duality nature...it's really hard to know if it has a topology. Because of its size it might not even have an 'appearance' because as the particle becomes smaller the more of the wave nature. Luckily we are big enough that our wave nature is very minimal. All particles are made out of energy or vibrating waves, etc. (E=MC^2). So, having such a small particle...hard to know. The problem with our model is that everything can be represented in probability clouds, like quarks,etc.
Also, on the topic of dark matter. There is a theory right now with neutrinos. This theory kind of sucks because it includes some concepts of String Theory, which is seriously lame. But here it goes. We know that neutrinos are ALMOST massless and neutral. But the thing is, that at some instances scientists are finding some neutrinos to have some recognizable mass that I can recall being notices like a proton! I don't remember if its as massive as a proton, but I know the particle has mass. Now, what the theory is, is that the neutrinos consists of a portion that has mass and one that has a VERY tiny mass. Now as the neutrino spins, a portion of the neutrino goes out of the space-time dimension and one side of the neutrino is exposed. Sometimes, the mass side of the nutrino is exposed in space-time. Thus, giving this massive neutrino being detected. This theory is to try to explain for that 'missing' mass in the galazies in the Universe.
Also, what about that idea that dark matter can go right through us(early post)? If that is true, yet it interacts with matter gravitationally, why can't we detect it? If we can detect the light cones from a neutrino why can't we detect dark matter effecting our own gravity? Is it because the quantity going through us is not that much and since gravity is a weak force it's hard to detect? I think the dark matter concept has to be majorly revised. And hopefully we can explain it before UFT. I mean, to not be able to account for 10% of our Universe's "stuff" and over 90% of matter-type...kind of a black eye in our scientific community isn't it? I don't buy the multi-dimensional theory and String theory to explain why mass exists and why it has these effects (ie gravity). |
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tomk80
SFN Regular
Netherlands
1278 Posts |
Posted - 07/26/2004 : 08:32:25 [Permalink]
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quote:
Originally posted by Skyhawk
I don't buy the multi-dimensional theory and String theory to explain why mass exists and why it has these effects (ie gravity).
Why not? String theory, and it's successor M-theory (IIRC), seem to be the ways to go to come to a unified theory. Also, IIRC, some of the predictions made by string theory have already been verified by physicists. So what is it about string theory that you don't like. |
Tom
`Contrariwise,' continued Tweedledee, `if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'
-Through the Looking Glass by Lewis Caroll- |
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