any one agree?
Unusual solutions are required when the wrong premise is used. Dark matter and dark energy are unusual solutions. I agree.
no.
I have always been a fan of modified gravity. It has always seemed more plausible to me that our equations/theories may need modification, rather than there is 90+ % of the universe which we just can not find; even after looking for nearly three decades. Of course billions have been invested in the current model and that will not change quickly; nor should it. Keeping an open mind is important but so is not jumping to conclusions. Just my opinion. Now fitting with the milieu of the site, all haters flame away 
Considering how difficult a neutrino is to detect, why would a person consider it impossible or unreasonable that there might be particles that are more difficult to detect, except perhaps en masse by gravitational effect, for example?
Zebras don’t exist.
[quote]NASA wrote:
I have always been a fan of modified gravity. It has always seemed more plausible to me that our equations/theories may need modification, rather than there is 90+ % of the universe which we just can not find; even after looking for nearly three decades. Of course billions have been invested in the current model and that will not change quickly; nor should it. Keeping an open mind is important but so is not jumping to conclusions. Just my opinion. Now fitting with the milieu of the site, all haters flame away
[/quote]
I agree, its much easier to say that all our theories account for everything and “since they do” there has to be 9 times more mass that we have no way of detecting in galaxies and the universe, then to say maybe we need to start from scratch or modify our theories with the data we have.
Well, ‘everything’ and its existence is pretty arbitrary anyway. So yes, they can and possibly do exist.
Where do the electrons go?
That’s all I wanna know.
I was gonna make a poop joke, but it’s too easy.
I can only leave so many serious threads alone before I explode.
Dark Matter and Dark Energy are just “place holder” words for stuff we dont know about yet… So in a sense no, they dont exist, but their effects can be scene and calculated. “Dark Matter” isnt a thing, its a concept for an observed phenomenon. Its just a word scientists use until they can actually find out what it is that is causing the observations.
It would be similar to having a working radio and not knowing how it worked, so you just call whatever causes it to work “Sound Matter” … And slowly you figure out its actuall vibrating waves, and then you figure out you can modify the amplitude and the frequency, and eventually you end up at “Radio Waves” both AM and FM. Scientists are still working on that whole second part, they got the name down 
As time goes by and searches turn up empty, it all starts to feel like the luminiferous aether of old. When I was in school they were looking for MACHOs and WIMPs, then MACHOs were out and CDM, WDM, and HDM were in. I am not saying they must be wrong, I am just trying to apply occam’s razor ala Jody Foster.
[quote]Lonnie123 wrote:
Dark Matter and Dark Energy are just “place holder” words for stuff we dont know about yet… So in a sense no, they dont exist, but their effects can be scene and calculated. “Dark Matter” isnt a thing, its a concept for an observed phenomenon. Its just a word scientists use until they can actually find out what it is that is causing the observations.
It would be similar to having a working radio and not knowing how it worked, so you just call whatever causes it to work “Sound Matter” … And slowly you figure out its actuall vibrating waves, and then you figure out you can modify the amplitude and the frequency, and eventually you end up at “Radio Waves” both AM and FM. Scientists are still working on that whole second part, they got the name down ;-)[/quote]
This is an apt description, I think.
I am, yet again, amazed at some of the stuff people discuss here. Does anyone who posted in this thread actually have enough background in physics in order to understand the research surrounding dark matter and energy, or is everyone just blowing hot air based on some discovery channel documentary?
[quote]NASA wrote:
As time goes by and searches turn up empty, it all starts to feel like the luminiferous aether of old. When I was in school they were looking for MACHOs and WIMPs, then MACHOs were out and CDM, WDM, and HDM were in. I am not saying they must be wrong, I am just trying to apply occam’s razor ala Jody Foster.[/quote]
Perhaps I was wrong, didn’t see this post at first. What is a MACHO or WIMP?
weakly interacting massive particle which is a hypothetical particle if found would give support the idea that dark matter exist.
[quote]stokedporcupine8 wrote:
Lonnie123 wrote:
Dark Matter and Dark Energy are just “place holder” words for stuff we dont know about yet… So in a sense no, they dont exist, but their effects can be scene and calculated. “Dark Matter” isnt a thing, its a concept for an observed phenomenon. Its just a word scientists use until they can actually find out what it is that is causing the observations.
It would be similar to having a working radio and not knowing how it worked, so you just call whatever causes it to work “Sound Matter” … And slowly you figure out its actuall vibrating waves, and then you figure out you can modify the amplitude and the frequency, and eventually you end up at “Radio Waves” both AM and FM. Scientists are still working on that whole second part, they got the name down
This is an apt description, I think.
I am, yet again, amazed at some of the stuff people discuss here. Does anyone who posted in this thread actually have enough background in physics in order to understand the research surrounding dark matter and energy, or is everyone just blowing hot air based on some discovery channel documentary?[/quote]
I’m certainly no particle physicist, but I majored in physics in college for a while and then dropped it because I found the rigor of it extremely boring (difficultly aside)… I still read frequently on the matter, although admittedly my current interest have not been dark matter or energy for a while, so my layman expertise is slipping.
I always love it when people “believe” or “not believe” in things that are evidence based… Hello, you dont get the option of believing in it or not, it either exists or it doesnt. The evidence will weigh in on the matter, not your beliefs.
If I had to guess as to why MOND or another alternate gravity theory seems to have rather little money (figuratively speaking) bet on it by physics in general, while dark matter is considered a better bet, is because general relativity has passed the test of very, very many predictions thus far.
Thus, a differing theory of gravity that has exactly zero verified predictions to its credit is unlikely to widely bet on as being probably correct.
In contrast, dark matter doesn’t require any differing from either general relativity or the standard model.
That doesn’t make it correct, but seems reasonable reason for it to be a preferred bet over MOND.
The unexpected current velocity of the Pioneer spacecraft is an interesting anomaly, though.
[quote]Lonnie123 wrote:
I’m certainly no particle physicist, but I majored in physics in college for a while and then dropped it because I found the rigor of it extremely boring (difficultly aside)… I still read frequently on the matter, although admittedly my current interest have not been dark matter or energy for a while, so my layman expertise is slipping.
I always love it when people “believe” or “not believe” in things that are evidence based… Hello, you dont get the option of believing in it or not, it either exists or it doesnt. The evidence will weigh in on the matter, not your beliefs.
[/quote]
I liked what you said. You’re knowledge of physics is probably greater than mine, I was a physics minor as an undergrad. I tended to take the “cool” mathematics-heavy classes though like qm and particle physics stuff.
Anyway… after all the CvE threads I’ve seen around here over the years and all the other dumb stuff I’ve read about science in misc. posts, I tend to have a short fuse when it comes to science/math related stuff. I’m no scientist by any means, but I like to think I know enough to know when I don’t know.
[quote]Bill Roberts wrote:
If I had to guess as to why MOND or another alternate gravity theory seems to have rather little money (figuratively speaking) bet on it by physics in general, while dark matter is considered a better bet, is because general relativity has passed the test of very, very many predictions thus far.
Thus, a differing theory of gravity that has exactly zero verified predictions to its credit is unlikely to widely bet on as being probably correct.
In contrast, dark matter doesn’t require any differing from either general relativity or the standard model.
That doesn’t make it correct, but seems reasonable reason for it to be a preferred bet over MOND.
The unexpected current velocity of the Pioneer spacecraft is an interesting anomaly, though.
[/quote]
Sounds like a good guess. Newton’s theory had a lot of predictive success too (to put it mildly), and that eventually went out the window. I have no idea where physics will go next, but it wouldn’t surprise me if in my lifetime we see a second major paradigm shift in physics, just like at the beginning of the twentieth century. All the elements are right–we have two fairly well worked out theories, both with empirical anomalies they can’t explain, both incompatible. Sounds just like the state of classical E&M and kinematics at the turn of the century, where then the contradictions where over the speed of light and the empirical anomalies included the photoelectric effect and the perturbation of mercury.
I was hoping for Gravity Probe B to turn up data contrary to general relativity, as that would have necessitated a new theory and considerably constrained the field of possibilities, but boringly enough the measurements were exactly as predicted.