Welcome to thebackpacker.com
create account login
To add this thread as a favorites, you need to first login.
Breif History Of Time.
“The book is going to be a 2 hour show on cable tonight and I am so pummped up about it.
It is on the Discovery Science Channel at 8 pm EST / 7 pm CST.
“That's cool you like Hawking so much, Crazy Mike! He's an incredible person.”
“Far out !”
“I have all his Cambridge Talks and all his other stuff books and such!
He is my favorite too read learn and listen too.
If you need anything I can get it!
“I have a hard stuff understanding his raw materials. But the Discovery Channel and TechTV programs I've seen on him break down his work very nicely. I think it's great he didn't let his handicap get in the way of his accomplishments. That's even more admirable than his work, IMO.”
“I love math!
Good Deal Artex!!!!
Call me sometime for info on all his stuff if you like!
Brief history of Rhyme.
“Yes, Steven Hawking kicks ass- But did you know how much ass he kicks?
Seriously though, I have some of his stuff on VHS, I wonder if it's available on DVD...”
“Yes it is CN.
Go to Amazon.com
I go to his website all the time I have lots of his math and lectures in .pdf format.”
“Thanks, I'll check out amazon. Have you gone to his gangsta rap site?”
“You know, this all reminds me...
My Subaru Outback came with a weather band radio. I can switch it on anytime for up-to-date reports from the U.S. National Weather Service. It's great to be able to get the latest forecast upon arriving at trail heads, especially for backpacking trips. But every time I'm trying to listen, I immediatley start thinking... "That guy sounds exactly like Stephen Hawking!" ...and I get so distracted that I miss the forecast completely ...Have to go back and listen again ...sometimes even a third time.
Is it actually him? ;-)”
“I do like the voice that his synth does I think its cool!
“The guy I'm a caregiver for is non-verbal and uses the same machine with the same voice and everytime I hear Hawking it makes me look because he sounds just like my friend. Wierd!”
“Ever notice how much Tony Blair sounds like 3CPO from Star Wars?”
“Try concentrating on what he says now.
“Hmmm. Protocol droid.... LOL”
“I saw a talk by Stephen Hawking while I was in colleg. Very interesting stuff. Haven't read or heard much of him since.”
“any repeats? id like to see that program”
“Its on all day I think?
“what are you doing home?”
“I have been sick for awhile!
“Hawking is obviously great, although his book (Brief History...) contradicts itself at times. My main problem with ALL mainstream cosmologists (Hawking, Thorne, Penrose, Wheeler, etc.) is their blanket acceptance of the existence of Dark Matter. Dark Matter is a mysterious undetectable substance required to make the known behavior of the universe fit the model of Einstein's General Relativity. Without Dark Matter, General Relativity does not even closely describe the observed large-scale nature of the universe (e.g., isotopic galactic rotation, overall universal structure, and other phenomena). While General Relativity has been very accurately confirmed in small-scale experiments whose dimensions range from laboratory bench-top apparatus to those of the size of our solar system; in other words, microscopic, the sheer size of the universe prevents us from performing controlled tests of the validity of General Relativity on the scale of intergalactic distances. However, this has not prevented mainstream cosmologists from applying a small-scale theory like General Relativity to the entire universe. But since we see things on the larger scale that seem to violate General Relativity, cosmology has invented Dark Matter as a way of making the universe "work right." The only problem, is that EVERY experiment performed to date has failed to arrive at a satisfactory explanation of what Dark Matter is. All we know is what Dark Matter isn't, which includes every form of matter known!
In the late 19th Century, a similar problem concerning the need for light to have a medium of propagation caused scientists of that era to postulate the existence of something called "the aether." At first, the aether seemed to "fit the bill," but as time progressed, as more became known of what the aether's definition had to be in order to allow light to behave according to observed phenomena, the more ludicrous became the definition of the aether. Then, in 1905, along came Einstein, who said (essentially), "there is no aether," and thus (after a while), arrived at the Theory of General Relativity.
So, now we have an equally ludicrous material called Dark Matter (and also, "Dark Energy"), whose nefarious existence is needed to preserve a sacrosanct theory. This smacks (to me, at least) as approaching religion rather than science.
Thus, while I admit that my grey matter can't even begin to compete with the likes of Hawking, I submit that even he doesn't have as many answers as he claims to have...”
“You seem very bright Forrest.as you know only parts of Theory of General Relativity are used in alot of the problems today becuase some of it has been disproven.
Take Black Holes for a example.
There are some things that can get out of a black hole right?
Do you know the other I don't seem to recall it?
I would like to pick you brain some day dude I like people who get into the very way out subjects and like to talk about them.
“I knew my dog was smart... but this is beyond anything i ever expected, he learned to use the computer! But he couldn't even spell his name right, how dissappointing... And how he got on the computer without me noticing is beyond me, what a crazy dog”
“maybe the dark matter is the dark side of the force”
“Hey 2scoops I taped it. Do you want me to send you the tape? I am watching it right now!”
“You don't have to delve into estoteric astrophysics before you run into the question of missing mass. Take gravitational effects, as an example.”
“Good use of words I wish I could spell that good!
“yes! hey wait, is this a ruse to get my address so you can stalk me? if so, i will email you my address right away”
“Get over yourslef!
“is "yourslef" a word?”
“You know what I ment!
“General relativity is a large-scale theory. Special relativity is small-scale.
What is Dark Matter? ”
“That is a good link dude!!!!
“'Yourslef' is a perfectly okay word after about five shots of tequila, LOL”
“General relativity is a large-scale theory. Special relativity is small-scale.
Actually, General Relativity is just that, the general relative nature of space-time in the presence of matter. In other words, General Relativity is the relativity of gravity and acceleration. Scale does not enter into the picture. In fact, Special Relativity is just a "special case" of General Relativity, one that is devoid of "inertial forces." General Relativity should work for all dimensional scales.
It's interesting that the link to "What is Dark Matter?" fails to answer its own question, and in fact, relies on inference to two theories (General Relativity and the Standard Model) to postulate its existence. The article referenced in the link is out of date, by the way. It has been shown since about 1998 that the presumed "halos" that General Relativity requires to exist around galaxies can NOT be made of baryonic matter, since the corresponding radio energy that would be emitted by such halos are not present. The article is also out of date in suggesting that so-called "massive" neutrinos could account for the dark matter - experiments in 1998 and 1999 showed that the upper bound on the mass of neutrinos must be less than or equal to 0.01 eV, while to provide the dark matter so needed by General Relativity, neutrinos must have a rest mass on the order of 3 eV - off by a factor of 300.
There ARE other theories about gravity other than General Relativity, but they are admittedly pretty far-flung. However, one common aspect of these other theories is that gravity is MUCH stronger at great distances than what is predicted by General Relativity. If this were the case, much of the large-scale behavior and nature of the universe could be explained. But then accepting this leads to unsavory results, such as the speed of light not ALWAYS being constant with respect to inertial reference frames - one of the foundations of relativity (and even clasical electrodynamics, if one looks at Maxwell's Equations carefully).
Don't get me wrong - I wholeheartedly respect the mass of work contributed to the body of knowledge by great ones such as Einstein and Hawking. I would never deign to equate my ruminations with their lofty posits. I do believe, though, that there is a tendency among my fellow physicists these days to hold that most of the universe's questions have been answered, to which I say, "balderdash!" As the small child who knew no better, I merely say that "the emporer has no clothes," or, "there is NO dark matter!"
If I am right, and there is no dark matter, then General Relativity is NOT "general," but is a special case of an even greater theory, one to which we are at this time ignorant.”
“Brick - in reading back over my original post, I see now why you made the reference to General Relativity as a large-scale theory, since it was I who called it a "small-scale theory." OK, what I was trying to convey (albeit poorly) was that the gravitational predictions of General Relativity have only been verified with experiments on the scale of our own solar system (and smaller), so that we can't say for sure how accurate General Relativity is over the much larger distances of the greater universe.
In fact, I believe that the galaxies are providing a test of General Relativity on a large scale, and are showing us that General Relativity does NOT paint the complete picture.”
“Who claimed that general relativity DID paint the complete picture? But so far it works where it's supposed to. That's good enough for me, for now. I do agree with you on the matter of all the questions of the universe being answered.
But why completely dismiss the possible existence of dark matter? Perhaps just take it with a grain of salt. What about the superstring theory and the 10- or 11-dimensional space that it talks about? Could it not be possible that this dark matter exists in one or more of the upper dimensions that we can't yet observe?”
“Sorry about the out of date links. Laziness on my part. Here's a more recent one (June 20, 2003). I admit I haven't read it all, more laziness, but here's the bottom line: "The idea, that some mysterious “dark matter” dominates over the ordinary chemical elements, first broached by Fritz Zwicky over 65 years ago, is now the common wisdom, confirmed by many different lines of evidence. For most astronomical observations the simplest possible choice seems to give an adequate description: the dark matter is primarily made up of elementary particles which are long-lived, cold and collisionless and has been termed cold dark matter. The most direct way to see if this choice is correct is via earth based laboratory particle detectors and several experiments are underway."
New Light on Dark Matter, pdf version
New Light on Dark Matter, html version”
“Hey Brick - thanks for the link.
I haven't come to my beliefs about dark matter overnight - I used to be a proponent of dark matter. However, over the years, as the definition of dark matter has become increasingly bizarre, I have been reminded of my days in modern-physics courses, in which the history of "the aether" was reviewed, often with not just a little humor - sort of like, "gee, weren't these people idiots to believe in something so ludicrous!?"
And yet, here we are, using yet another mysterious substance to preserve the theoretical status quo.
As for claims about the completeness of General Relativity, one only has to read anything written by Hawking, or Thorne, or Wheeler to get the message that General Relativity is the "Final Word" on the subject of gravity - period.
And my whole point is that General Relativity doesn't always work where it's supposed to (for example, in describing the rotation of galaxies), which is why dark matter had to be invented...
It appears to me that the last great hope for dark matter are Weakly Interacting Massive Particles (or WIMPS - !), which is just another way of saying, "OK, our theory HAS to have a bunch of mass that we can't see in order to be correct, so we'll say that there are all these particles with mass that have NO OTHER property with which to indicate their existence."
An experiment that I would propose is to study the emmission spectra of black holes (Brick - I expect that you're a physicist, so you know what I mean, but for the benefit of others that may read this: black holes actually EMIT a LOT of light. This is due to radiative energy given off by particles as they are accelerated to essentially the speed of light just before they disappear beyond the Schwarzschild horizon). There are presumably black holes that have been observed in the outer spiral arms of certain galaxies. Since these black holes should reside within the galaxies' halos, they should be accreting LOTS of dark matter, and this dark matter should be detectable in the emmission spectra of the black holes.”
“Physicist in training actually.
It seems I was ignoring your main point about general relativity. I can see why you don't like dark matter but like I said, I won't discredit it until it has been satisfactorily disproved (hey, if the religious zealots can use that excuse with God I can use it here), not just because of a lack of evidence. That's not to say
it absolutely must exist, I'm just keeping options open.
As for general relativity being the final word on gravity, what about the quantum theory? Do any of those authors deny that there are discrepancies between general relativity and quantum theory? If they think gen. rel. is final then what is all this talk about unifying theories?”
“I have a headache.”
“This is when I get up from the campfire and head to bed (before my buzz gets ruined.)”
“OK Brick, I think we're starting to annoy those that are not of "the illuminati." But thanks for the opportunity to rant - you've made some good points, and I enjoyed the repartee. You're certainly in good company in defending the existence of dark matter (Thorne, Hawking, etc.), while I'm out there with the crackpot fringe. It's a good thing I don't earn a living as a cosmologist, because I could never hold my own with that crowd! I'm just another applied physicist (I work in lasers and optics) who has questions about cosmology that may solely originate from ignorance. I do have my suspicions, though, that there might be more people (ones more "in the know" than I) who have their own secret misgivings about the direction cosmology has taken in the last fifty years...”
“You guys have brought up some good arguments I like the links most of all very good reading!
“Food goes in here. points at mouth”
“When you learn and make the brain swell it is good for the body!
“my brain hurts....”
“Thats a good pain!
“I'm curious as to who the identities are behind those two screen names - Pinky and the Brain?”
“Hehe. Any time Forrest. I can't claim to be "in the know" about cosmology, my direction of study is on the opposite end of the spectrum at the quantum level, I'm just another curious soul.”
Post a MessageIn order to post a response to this thread you must first be logged in. If you do not already have an account, you must first create a new account.
Ready to Buy Gear?
Great Outdoor Sites