why does dark energy need to exist?

R1 · Feb 11, 2007

I just read a quantum spacetime model that seems to not require the existence of dark energy If I understood it . I'm hoping to understand it better, is everyone familiar with it? I hope I understand it, It apperars that expansion is the natural behavior of space-time itself, spacetime is neither nothing nor empty, but it's quantized and consisting of fermionic/bosonic points, I think self replicating and with nothing between them but true nothingness, like the space inside an atom, nothing at all except just room for the next quantum state or something like that. <div class="Discussion_UserSignature"> </div>

why06 · Feb 11, 2007

can you link the article? <div class="Discussion_UserSignature"> <div>________________________________________ </div><div><ul><li>your move...</li></ul></div> </div>

R1 · Feb 11, 2007

hi why06, let me see if I can cut and paste it's rather long: http://home.earthlink.net/~dolascetta/PhysicsFrameSet.html <div class="Discussion_UserSignature"> </div>

why06 · Feb 11, 2007

Your right it is long. Ill give it a shot, but don't expect any miracles. I remember the word ferionic....probalbly from the word fermion. I think that is the kind of particle an electron is. You see there are several kinds of sub-atomic particles. the three we find in atoms I believe are just the most common of each. I may be wrong though. Ill read the article (well skim it) and see what I can come up with. Until then maybe someone who knows in detail this kind of stuff can give you some help. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <div>________________________________________ </div><div><ul><li>your move...</li></ul></div> </div>

R1 · Feb 13, 2007

This is totally amazing, I think it's talking about the quantum foam (the stuff we all used to be when we first joined the posts <img src="/images/icons/smile.gif" />) It'll be a while before I understand the entire article for me too. I had just started wondering what quantum theory was thinking about spacetime when I stumbled on this. <div class="Discussion_UserSignature"> </div>

bonzelite · Feb 13, 2007

why does dark energy need to exist? to smooth over current theory, to make it "work." theory must be mated to other theory, and that then to other theory until nothing is believable nor bears resemblace to reality, becoming an abstraction of an enigma shrouded in a mystery. this keeps all of the eggs in a row and the man happy. that is why dark energy needs to exist.

tdamskov · Feb 13, 2007

bonzelite, please go preach in another thread - you're not contributing with a reasonable answer to the question nor are you actually presenting any science, you're just stating pure opinion. Please stop disrupting a reasonable thread with your personal rants. This is not about theory but observation. According to observation of redshift rates on distant galaxies, the universe seems to be expanding at an accelerated rate. Based on our understanding of redshift, scientists are trying to explain why. Perhaps the theory will be proven wrong or the understanding of redshift may change but that's the way science works.

siriusmre · Feb 14, 2007

Bonz, I agree with your answer. I would have posted something similar. Dark matter exists only because the graity-only equations say that it has to. tdamskov: Based on our understanding of redshift,... Well, that's the rub, eh? What if redshift IS NOT accurately understood? What if the universe IS NOT expanding? (At any rate, accelerating or otherwise!) What if redshift DOES NOT equal distance, as Edwin Hubble himself warned? What if, instead, redshift were an INTRINSIC characterisitc of astronomical objects? What if redshifts exhibit QUANTIZED behavior? Would that matter? <div class="Discussion_UserSignature"> </div>

nojocujo · Feb 14, 2007

Dark energy needs to exist because of the observed apparent brightness associated with SN1a. The hubble velocity indicates a cosmological expansion associated with the observed redshift. Dark matter and dark energy are ways to reconcile observations with the current models. I would not say that dark energy has to exist. But it is the next to best explanation for the loss of photons associated with high z SN1a. The best explanation would be a local inflationary expansion of spacetime associated with SN1a where the photons enjoy an inverse deflection as they follow the expanding geodesic caused by the changing gravitational potential of the SN1a where the remnant represents about half the mass and the excretia accelerated at 1/2 c represents the other half. I don't think GR can accurately represent that expansion with just a modified ricci tensor. The redshift is another issue altogether.

R1 · Feb 14, 2007

what about the model that describes (as I understand it) spacetime expansion at the quantum level being a natural property of spacetime? alright, so we observe dark spacetime expansion energetically, but doesn't quantum theory explain it well? It makes me wonder if science has totally disproved the quantum spacetime theories that don't require a mysterious dark energy but I have not yet observed quantum spacetime theories being totally wrong In fact the more I observe observe quantum theories the more they make sense <div class="Discussion_UserSignature"> </div>

alokmohan · Feb 16, 2007

How else you find the mass of Universe,I mean account for it?

tdamskov · Feb 16, 2007

<blockquote>In reply to:<hr />Bonz, I agree with your answer. I would have posted something similar. Dark matter exists only because the graity-only equations say that it has to.<hr /></blockquote> Dark matter has little to do with dark energy. <blockquote>In reply to:<hr />tdamskov: Based on our understanding of redsh[ift,... Well, that's the rub, eh? What if redshift IS NOT accurately understood? What if the universe IS NOT expanding? (At any rate, accelerating or otherwise!) What if redshift DOES NOT equal distance, as Edwin Hubble himself warned? What if, instead, redshift were an INTRINSIC characterisitc of astronomical objects? What if redshifts exhibit QUANTIZED behavior? Would that matter? <hr /></blockquote> Glad to see you took the hook, sinker and all ;-) This is about how science works. True, we can't know for sure that our understanding of redshift is right. If we're completely on the wrong track, things will look different and dark energy may not be needed to explain observation. BUT... Redshift IS established science, every empirical evidence shows that our understanding of how it works is correct. It doesn't mean phycisists won't keep looking for new experiments to verify theory. But until something radical happens all science will have to work on the assumption that we DO understand redshift. Cosmologists simply have to build on the work of other scientists - just like other scientists have to reconcile their theories with cosmological observations. I can assure you many scientists are not happy with the concept of dark energy and are pouring their energy into explaining the puzzle or coming up with alternatives. You make it sound as if scientists "need" dark energy - they don't!! There are simply observations which need to be explained one way or another.

ianke · Feb 16, 2007

The discussion of Dark energy is one that I take a personal interest in. However, I believe that the thread started with a question from John1R about the paper "Inflation Spacetime". Do any of you guys have any opinion on the "Inflation Spacetime theory" itself? It seems to me (at first read through anyway) that the author has some interesting thoughts. Is this a train of thought that deserves more work or is it going in the wrong direction? Like John1R, I find that you guys have a pretty interesting way at getting to the meat of the issue. How about some reply on this? Thanks <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

siriusmre · Feb 16, 2007

<blockquote>In reply to:<hr />Dark matter has little to do with dark energy.<hr /></blockquote> Touché. I mistyped. However, each is as fictional as the other. <blockquote>In reply to:<hr />If we're completely on the wrong track, things will look different and dark energy may not be needed to explain observation.<hr /></blockquote> No, things will not look different. The way that we interpret what we see will be different. The evidence is there now for those with eyes to see it. <blockquote>In reply to:<hr />Redshift IS established science, every empirical evidence shows that our understanding of how it works is correct. It doesn't mean phycisists won't keep looking for new experiments to verify theory.<hr /></blockquote> What empirical evidence? Has someone actually travelled to a distant star to determine exactly and unequivocally how far away it is and then correlated that with our redshift readings of that star? Short of that, any "empirical" evidence that equates redshift with distance is simply an analog that may or may not be accurate. What about observations that falsify theory? What if, instead of "tweaking" the theory, the theory was recognized as falsified and minds were truly open to considering something COMPLETELY diferent? (Cf. the dirty snowball/icy dirt ball "theory" of comets. How many ways does this hypothesis need to be falsified before it is scrapped as a theory?) Has anyone actually considered the possibility that the theory (and its underlying assumptions) might be wrong? Who has gone back and questioned each assumption from the beginning? The current path has clearly led us up some blind alleys. Is there perhaps another completely different way of looking at things that would help us steer clear of some of those pitfalls? That's what I'm talking about. Not dithering around the margins, refining work tha <div class="Discussion_UserSignature"> </div>

why06 · Feb 16, 2007

Well I finally had time to read it: I believe you have it spot on. <img src="/images/icons/smile.gif" /> But this theory goes deeper. It does not just give a reason for the expanding universe, but it supplies a possible candidate for dark energy as well as matter. I guess these points are supposed to be expanding. I wish I knew what they ment by: "quantum points" though... <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <div>________________________________________ </div><div><ul><li>your move...</li></ul></div> </div>

why06 · Feb 16, 2007

Well actually Im still reading it, but I get the just. <div class="Discussion_UserSignature"> <div>________________________________________ </div><div><ul><li>your move...</li></ul></div> </div>

tdamskov · Feb 16, 2007

<blockquote>In reply to:<hr /> What empirical evidence? Has someone actually travelled to a distant star to determine exactly and unequivocally how far away it is and then correlated that with our redshift readings of that star? Short of that, any "empirical" evidence that equates redshift with distance is simply an analog that may or may not be accurate. <hr /></blockquote> We have indeed done lab experiments measuring the redshift of light to a very high precision. We bounce lasers on reflectors on the moon. We're able to measure redshift within our solar system. We easily measure light from distant stars and compare those spectrums with our own star. The maths behind redshift are supported across multiple scientific disciplines and confirmed by theory. It is empirical evidence as far as it's testable. When would you consider redshift observations validated? When we arrive at the nearest star and things check out? Nearest galaxy? Nearest SN1a supernova? Nearest cluster? Do you want all cosmologists to gather in a circle around a campfire and wait until redshift observations are confirmed? <blockquote>In reply to:<hr /> Has anyone actually considered the possibility that the theory (and its underlying assumptions) might be wrong? Who has gone back and questioned each assumption from the beginning? The current path has clearly led us up some blind alleys. Is there perhaps another completely different way of looking at things that would help us steer clear of some of those pitfalls? That's what I'm talking about. Not dithering around the margins, refining work that has already been done and based on possibly faulty assumptions. Can you name any "mainstream" scientists that have gotten funding to question the base assumptions of the redshift-equals-distance issue? That is the loose thread in the sweater that is the "Big Bang." Pull that and the whole thing starts co</blockquote>

heyscottie · Feb 16, 2007

Hear, hear! And by the way, your English is quite excellent. I'd say it's better than many primary English-speaking posters I've seen...

siriusmre · Feb 16, 2007

<blockquote>In reply to:<hr />We have indeed done lab experiments measuring the redshift of light to a very high precision. We bounce lasers on reflectors on the moon. We're able to measure redshift within our solar system. We easily measure light from distant stars and compare those spectrums with our own star. The maths behind redshift are supported across multiple scientific disciplines and confirmed by theory. It is empirical evidence as far as it's testable. When would you consider redshift observations validated? When we arrive at the nearest star and things check out? Nearest galaxy? Nearest SN1a supernova? Nearest cluster? <hr /></blockquote> I'm not saying that redshift is not real. I am saying that we are interpreting it wrong, especially as it relates to cosmic distances, etc. What if light in our system and beyond is not just traveling through an empty void? What if it is traveling through a plasma? How might that effect extraterrestrial redshift measurements? I am not suggesting that scientists work for monetary gain. I know that that is not completely true. There are, however, scientists--especially in university settings--who get the funding for their work from organizations that will only fund certain kinds of research. That cannot be denied. I have no doubt that there are thousands of well-meaning and dedicated scientists working as hard as they can...along a particular line of thinking. Where are the stories about those that are doing truly radical work? Work that really goes "back to formula" and questions the most basic assumptions? I am sure that many are excellent mathematicians. Perhaps that is part of the problem: Astronomy has been taken over by mathematicians. "Black holes" and "dark energy" are fine as long as you are talking about an equation. When you then try to say that because the equation says it is so, then that must be reality, I think you run into a problem. That is why astronomers <div class="Discussion_UserSignature"> </div>

tdamskov · Feb 16, 2007

<blockquote>In reply to:<hr /> I'm not saying that redshift is not real. I am saying that we are interpreting it wrong, especially as it relates to cosmic distances, etc. What if light in our system and beyond is not just traveling through an empty void? What if it is traveling through a plasma? How might that effect extraterrestrial redshift measurements? <hr /></blockquote> There are theories working on the assumption that redshift is caused by plasma "filtering"; a simple search on Google reveals as much. But they have a difficult time against established theory, as well as observations. For example: Why would intergalactic plasma exhibit redshift filtering when far denser plasma inside our galaxy (or in labs) doesn't do that to any measurable degree? <blockquote>In reply to:<hr /> I have no doubt that there are thousands of well-meaning and dedicated scientists working as hard as they can...along a particular line of thinking. Where are the stories about those that are doing truly radical work? <hr /></blockquote> I would say that the paper on quantum cosmology linked earlier in this thread is an excellent example of radical thinking. I think science is all about the delicate balance of being just radical enough while based on the solid work of others. On the topic of funding, I think I will simply choose to disagree - further discussion doesn't belong in this thread. <blockquote>In reply to:<hr /> Where is the scientific maverick who asks, "What else could it be?" Who truly questions everything? Yes, part of the scientific method is to confirm and validate, but another, even more important part is FALSIFICATION. <hr /></blockquote> I couldn't agree more with the last part. That is what science is all about and I belive that is being done every day by all scientists. But the type of "radical thinkin

vandivx · Feb 17, 2007

<blockquote>In reply to:<hr />I would say that the paper on quantum cosmology linked earlier in this thread is an excellent example of radical thinking. I think science is all about the delicate balance of being just radical enough while based on the solid work of others.<hr /></blockquote> I also went to look at that paper and have to say if there is anything radical about it, it is radical foolishness divorced from any grounding in reality, simply juggling physics terminology and making a stupendous mishmash of it, that's what I see there excuse me but I fail to see how it is radical and how it is based on the solid work of others, how can it be radical when underneath all that gobledygook the guy works into his paper just about every 'non-solid' theory out there starting with BBang and what not else when I see stuff like that I feel like forgeting about physics and instead spending my time on growing pelargonias or playing some game on my PC or something, I mean if this passes for thinking than I don't want to think anymore vanDivX <div class="Discussion_UserSignature"> </div>

dragon04 · Feb 17, 2007

Correct me if I'm wrong, but if we assume that space-time is limited to 3 physical dimensions and one time component, then "dark matter" and "dark energy" are likely components that have to be identified and quantified. However, seeing that we can't quantify gravity in 4 dimensional space-time or explain the observational results of universal expansion based on "known" masses and forces, doesn't that imply that there are forces acting on the Universe "outside" our 4 dimensional space-time model? If we want to neatly tie up loose ends into a pretty package in the Einstinian Universe, do we need dark matter and dark energy, or could we factor in the additional mass we can't "see" due to recession at relative superluminal velocities past the observable edges of the Universe? While certainly I'm a novice and layperson, it seems to me that only a few conditions can apply. 1. The Universe is much larger than we can observe and that the as yet undiscovered mass that reconciles an accelerating expansion with what we can observe lies outside what we see. 2. That there is much more matter in the observable Universe than we can quantify. Dark Matter. 3. That there is a force as yet unexplained acting on all matter within the Universe that reconciles observable mass and observable expansion. Dark Energy. 4. A combination of 2 and 3. 5. Forces "outside" of 4 dimensional space-time as yet undiscovered. It seems to me that Nature likes economy. It abhors complexity. <div class="Discussion_UserSignature"> "2012.. Year of the Dragon!! Get on the Dragon Wagon!". </div>

chembuff1982 · Feb 17, 2007

This article is a lot of he said she said, with maybe this and maybe that, the perspective is so open and broad. With speculated mathmatical assumptions without a standard backing. Keep the work up ladies and gents, but as of now, this hypothesis and conclusions in this whole article, would fit right in at the local landfill. Big science words and math words, might fool you, but I read the article, and it's legitimacy is a joke. <div class="Discussion_UserSignature"> You may be a genius, but google knows more than you! </div>

R1 · Feb 17, 2007

---------------------------------------------------------------------------------------------------------- (vanDivX

I also went to look at that paper and have to say if there is anything radical about it, it is radical foolishness divorced from any grounding in reality, simply juggling physics terminology and making a stupendous mishmash of it, that's what I see there excuse me but I fail to see how it is radical and how it is based on the solid work of others -------------------------------------------------------------------------------------------------------------- vanDivX, you're not being specific about any issues you have with that article, you're very generalized, It's difficult for me to learn anything meaningful from what you say unless you're more specific , as for the solid work of others I think for the most part that would be the Quantum theories, these I believe developed to understand how things worked closer to the groundings in reality, in fact for example, chemists worked on electron microscopes and molecules and atoms, and then scientists developed a better understanding at the quantum levels and how fermions and bosons interacted to form what the chemists called atoms, etc. to the best of my current understanding, everyones work has been solid work, even Newton and Einstein Their work has limitations because we begin to study reality at a closer level to its groundings,the reality foundations, Unless I'm wrong, they found that some of Einsteins work doesn't apply on certain frames of reference, then Quantum scientists understood things in more detail, then there was some kind of issue with having a need for a 1/2 spin particle , then String theory started to develop, and I got confused with the string theories and looking at the same things from a different frame of reference Personally, I do think there are mo <div class="Discussion_UserSignature"> </div>

yevaud · Feb 17, 2007

In answer to one of your points (and this also answers other points variously made in this thread). I believe VanDivX will agree with me on this. Extra dimensions were originally "added" as many highly complex equations modelling a physical behavior simplify in higher dimensions. As you'd said, nature prefers an elegant simplicity, not abhorrent complexity (well on a certain scale anyways). Maxwell's ugly equations (the scars still have not faded) simplifies to a single equation in five dimensions out of which all of the familiar equations may be derived. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

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