Came across this and thought it would be of interest:
If it proves correct, cosmology will have to step back to the drawing board.
Can’t wait for Dr. Becky’s January 16 ‘Night Sky’ video!
“Dark energy may not exist” is just another way of saying “the expansion of the universe may not be accelerating after all”. From my understanding as an armchair physicist, dark energy is a placeholder name for whatever is causing expansion to accelerate.
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True. The interesting aspect is that if there’s no dark energy then the amount of dark matter is greater than presently thought.
- God of the growing gaps?
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real?
dark = big fat question mark
It just means that the current theory doesn’t quite work and this could point to just about anything including something wrong with the theory itself. Most likely some missing piece of the puzzle.
I like Neil Turok’s idea in which there is no need for dark energy and dark matter is just neutrinos. AND it is testable (real science!).
If it proves correct, cosmology will have to step back to the drawing board.
Already been there for a while now.
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Just last week I stumbled onto a discussion (rather heated) between someone advocating that view of dark matter and someone arguing for WIMPs. I was surprised; I thought WIMPs had been ruled out.
I don’t have a particular view on this, however, it has aroused my interest and I would like to watch that discussion if there is an online reference to it St. Roymond?
FYI
Given the above uncertainty, what is the likelihood that it turns out that gravity is the dark matter/energy? Perhaps the two [dark energy and gravity] are so interrelated that they are kinda the same thing??
I mean if magnets have two poles where one attracts and the other repels, why not the same for gravity and dark energy???
I found this…
The most recent matching content online that I can find is two years old; most is four or five.
Of those I found, this covers the basics though it’s really light on the neutrino angle:
Along the way it also goes into some fascinating aspects of how particles behave.
Here’s one that looks promising, though the presentation isn’t the greatest (it reminds me of presenters of papers at conferences who hate public speaking); it also quickly gets rather hefty/dense (clearly expecting the audience to be familiar with the subject):
While looking, I learned that the term “dark matter” was actually coined in the early 1930s! and that along with the cosmic microwave background there is a cosmic neutrino-flux background.
I also noticed that advocates for the different positions can be extremely vehement against other views.
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I think that would require that gravitons exist and themselves have mass plus to have something corresponding to charge.
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Im just into the first video…
What do you think about the statement that all stars in the milky way seem to orbit at the same speed 200km/sec and most other galaxies are the same?
This doesn’t seem consistent with the idea that planets within our solar system orbit at different speeds. Why the difference there?
Also, why would there be more dark matter out towards the edges? In a whirlpool (in a swimming pool) the dirt gravitates towards the centre of the whirlpool. Is this relevant? (perhaps I’m just getting my wires crossed…i will figure this out in time once i get into the right headspace here)
Finished the first video…how frustrating that the collider in Switzerland still hasn’t detected either the WHIMP or AXION.
I think the first video covers the topic quite well…so i wont watch the second one for now as it appears to focus more on WHIMPS in more detail. Do you agree with that St Roymond or does the second video offer something id really need?
Im still suspicious that our desire for dark matter to actually be something might ignore common sense that perhaps it really is just empty space?
I like this stuff…i am looking forward to the future…hopefully its resolved in my lifetime.
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Exactly – that’s why scientists concluded that there is matter we can’t see; it changes the behavior of things in orbits. It’s not quite as simple as how Neptune was found, but the principle is the same: something with a lot of mass is exerting a pull that changes the orbits of stars around the center.
It’s apparently more like what the water does: in a round pool, get the water in a vortex and it migrates outward.
What’s frustrating is that if the U.S. had completed the SSC (Superconducting Super-Collider) in Texas the axion might have been found by now – probably not WIMPs given how they’re not “normal” matter so crashing normal particles together wouldn’t find them.
Unless you’re prepared for a master’s-degree level of presentation the second video isn’t likely to help much. I watched the whole thing and probably didn’t even grasp a fifth of it, and I took upper-level physics courses.
It’s not about any “desire”, it’s like the problem with Uranus not orbiting the way it should have – that told astronomers that there was some mass out there they hadn’t seen yet, a “dark planet”. It took a really good telescope and some really fine mathematics to figure out where to look, and eventually it was found. Dark matter is the same problem: there is mass out there we can’t see, but this time it isn’t in one place to be found, it’s all over. It isn’t just the issue with galaxy star rotation, either; the structure of how galaxies are spread across the universe doesn’t make sense unless there is a lot of matter that we can’t see.
As for empty space, we’ve known for a long time that the majority of matter in the universe isn’t in the things we can see; even most ordinary matter is out between the stars and even between galaxies; then there’s the “virtual vacuum” that quantum theory points to, so it shouldn’t be surprising that there’s still more out there (as one cosmologist said a while back, empty space is getting crowded).
Personally I get a kick out of it from a sort of theological perspective: I can just see God watching scientists and saying to Gabriel, “These guys think they’ve got it figured out, but watch! They’re about to stumble on a real puzzle!”
If it isn’t resolved in mine I wouldn’t be at all surprised to get to heaven and learn how it all works, and probably think, “That’s so obvious!”
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I think dark energy is a good example of how scientific knowledge goes forward.
Scientists make mathematical calculations or other theoretical work and make predictions based on that. Others then try to collect data to support or disprove the predictions.
Sometimes the search finds data that supports the predictions and strengthen the credibility of the theoretical model.
Sometimes the effort to find supporting data is futile, questioning the validity of the theoretical model that produced the predictions that do not seem to be true. That leaves an interesting question: what is wrong in the model? Should we abandon the model totally or change something in the model? Are the basic assumptions wrong, or do we perhaps miss an important factor from the model?
Answering all these questions can bring scientific knowledge forward even more than when we find supporting evidence for the theoretical model.
Dark energy is at the phase where there is a prediction (or predictions) but not yet sufficient supporting evidence.
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I occasionally find myself hoping that someone will come up with a modification to Einstein that will eliminate the need for dark matter, but then I remember that there are galaxies that do behave as ‘expected’, and sigh.
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If many galaxies seem to behave as ‘expected’, it is not a full proof for the prevailing theory. Several competing hypotheses can make similar predictions about certain matters, even when they make differing predictions about some other phenomena.
It is interesting to see what happens in the future - do we find evidence for dark energy or do we get a competing theoretical model that does not need the ‘dark energy’ component?
The Creation Ministries International video “Evolution’s Achilles Heels” claims that dark matter is just a fudge factor invented to cover up problems with the Big Bang; however, Jason Lisle has pointed out that this is untrue; the concept of dark matter originated as a way to explain why galaxies and galaxy clusters usually act as though they have extra mass. As Lisle has been willing to endorse bad young-earth astronomy claims, I’m not sure why he is being honest on this topic.
The relatively constant orbital speed of stars is in their orbits around the central black hole of the galaxy. There are all sorts of other motions going on as well. The orbits of the planets around the sun is dominated by the sun’s gravity and follows the expected patterns for gravity (with Mercury noticeably following Einstein’s formulas rather than Newton’s usually pretty good approximation). The orbit of the solar system around the central black hole follows the general pattern of behaving as if the galaxy has a lot of mass further out than what we see; however, we’re not far enough out for the effect to be as obvious. Stuff orbiting near the visual fringes of the galaxy, such as certain globular clusters, tend to be what’s obviously moving faster than can be explained without dark matter.
The obvious alternative to dark matter existing is that our formulas for gravity aren’t quite right. But they seem to work quite well for all other situations that we can test. Efforts to develop a new formula for gravity exist, but haven’t gained a large following.
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At the moment I lean towards dark energy not being real but an artifact of relativity not yet taken into account.
For dark matter, I don’t see any way around it.
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I think Im right in saying a number of Einstein’s predictions based on his theories were only evidenced in reality a number of years later? The observations proved him right.
Repeatedly – including implications he had not seen. It may be the best-confirmed theory in the history of science.