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Old 06-05-2019, 06:32 AM
 
Location: Maryland
2,158 posts, read 729,163 times
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I saw this list of explanations for the layman of a lot of the current thinking, just thought it was interesting.

https://listverse.com/2019/05/28/10-...f-dark-matter/
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Old 06-05-2019, 10:43 AM
 
Location: Seattle
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At this point one has to wonder whether we will ever actually determine the true nature of dark matter. Every experiment thus far has failed, and there are fewer and fewer corners that haven't been searched yet.
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Old 06-05-2019, 11:11 AM
 
Location: Maryland
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Quote:
Originally Posted by rjshae View Post
At this point one has to wonder whether we will ever actually determine the true nature of dark matter. Every experiment thus far has failed, and there are fewer and fewer corners that haven't been searched yet.
I know. At 71, one of my saddest thoughts is that I will not live to see answers to many of these mysteries. Couple this with a thread I posted some weeks ago about the universe expanding much more rapidly than cosmologists thought, it really makes one think some major revisions in our thinking are coming due. I cannot imagine what they will be.
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Old 06-05-2019, 11:25 PM
 
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A friend of mine showed me a hypothesis he was working on for a presentation he was about to give (he's a physicist and engineer) regarding dark matter and dark energy that I thought was interesting. He postulated that dark matter and dark energy were manifestations of other universes (in the multiverse) exerting a force on our own. Multiple universes interacting with each other. I wish I could remember more of the details but it's been a while.
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Old 06-06-2019, 09:57 AM
 
22,774 posts, read 17,250,171 times
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Quote:
Originally Posted by Adric View Post
A friend of mine showed me a hypothesis he was working on for a presentation he was about to give (he's a physicist and engineer) regarding dark matter and dark energy that I thought was interesting. He postulated that dark matter and dark energy were manifestations of other universes (in the multiverse) exerting a force on our own. Multiple universes interacting with each other. I wish I could remember more of the details but it's been a while.
Your friend's hypothesis is not unique and has been suggested by cosmologists who are proponents of the multiverse theory. The idea that a force from outside our universe is being exerted on our universe has been hypothesized based on studies of the temperature irregularities in the cosmic background radiation which is the afterglow of the big bang. NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) detected slight deviations in the general expansion of the universe instead of a uniform expansion. This suggests to some that something from beyond our universe could be pulling at galaxy clusters.

The article below from 2009 addresses this.

https://cosmosmagazine.com/space/wei...-edge-universe
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Old 06-06-2019, 06:44 PM
 
Location: Ohio
20,681 posts, read 14,654,220 times
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Quote:
Originally Posted by rjshae View Post
At this point one has to wonder whether we will ever actually determine the true nature of dark matter. Every experiment thus far has failed, and there are fewer and fewer corners that haven't been searched yet.
Ether.

I don't actually believe dark matter/energy exists.

Quote:
Originally Posted by LesLucid View Post
I know. At 71, one of my saddest thoughts is that I will not live to see answers to many of these mysteries. Couple this with a thread I posted some weeks ago about the universe expanding much more rapidly than cosmologists thought, it really makes one think some major revisions in our thinking are coming due. I cannot imagine what they will be.
They could be wrong.

I'm sorry, but Hubble is not the end-all-be-all.

In our life-times, we've seen the Universe grow in both size and age, from what we were told in elementary school, high school, college and beyond.

That growth was due to better technology providing more data and a better understanding.

The Universe is probably bigger and older than what they currently believe, and something better than Hubble will prove (or disprove) that.

The whole idea of dark matter/energy is predicated in part on the belief that the observable rotational speed of galaxies and clusters of galaxies is faster than the calculated speed.

Their calculations or observations or both could be in gross error.

Our Sun is a G-Class star. K-Class stars are similar, just a tad cooler. But, the celestial mechanics that result in the formation of G/K-Class stars always results in the formation of 6-12 terrestrial and gaseous planets. Given that there are 10,000 G/K-Class stars within 50 light years of Earth, that's 60,000 to 120,000 planets, but they refuse to believe that. They think planets are rare, when in fact they aren't, and the amount of Space debris left over from the formation of any star is far greater than they're willing to admit.

The point being there's a lot of reasonable explanations for the alleged discrepancies that don't require exotic theories.
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Old 06-07-2019, 03:59 AM
 
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Originally Posted by Mircea View Post
Ether.

I don't actually believe dark matter/energy exists.
There’s an alternative theory that’s been thrown around, which is dark flow, and tries to incorporate dark matter and energy into a single phenomena.

Quote:
They could be wrong.

I'm sorry, but Hubble is not the end-all-be-all.

In our life-times, we've seen the Universe grow in both size and age, from what we were told in elementary school, high school, college and beyond.

That growth was due to better technology providing more data and a better understanding.
Yes, there’s a lot that we don’t know. For one, the actual Hubble constant is still being debated, with recent results contradicting previous findings.

Quote:
The Universe is probably bigger and older than what they currently believe, and something better than Hubble will prove (or disprove) that.
The total universe may even be infinite. We still don’t even know if there is curvature to space-time.

Quote:
The whole idea of dark matter/energy is predicated in part on the belief that the observable rotational speed of galaxies and clusters of galaxies is faster than the calculated speed.

Their calculations or observations or both could be in gross error.
It’s also been suggested that dark matter could be the imprint of another universe interacting with ours. I’m fascinated by the different multiverse concepts out there but they are in the realm of speculation.

Quote:
Our Sun is a G-Class star. K-Class stars are similar, just a tad cooler. But, the celestial mechanics that result in the formation of G/K-Class stars always results in the formation of 6-12 terrestrial and gaseous planets. Given that there are 10,000 G/K-Class stars within 50 light years of Earth, that's 60,000 to 120,000 planets, but they refuse to believe that. They think planets are rare, when in fact they aren't, and the amount of Space debris left over from the formation of any star is far greater than they're willing to admit.
Oh wow!! That’s a huge number. I was under the impression that most of our stellar neighbors were Red Dwarfs. As far as planets go, I think most cosmologists have come to terms with the fact that planets are rather common as they are a part of the natural formation of a star system.
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Old 06-07-2019, 08:25 AM
 
Location: Maryland
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I’m a biologist, so forgive my ignorance of this field. Lawrence Krause gave a talk years ago which seemed to paint a picture of a fairly well settled view of the past, present and future of our universe. It’s a very entertaining video, which I’ve watched through several times. Do any folks here know whether this is still considered “current thought”? I realize the recent concern about faster than expected expansion of the universe could be a complication but, other than that, is this talk still considered mostly valid? I hope you enjoy the video. There is a significant portion discussing dark matter/energy.


https://m.youtube.com/watch?v=-EilZ4...ature=youtu.be
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Old 06-07-2019, 01:00 PM
 
Location: Seattle
2,257 posts, read 483,431 times
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^ Yes it seems to still be mostly valid, although the nature of dark matter remains indeterminate. It's at a high enough level that it skips most of the messy details. Pretty funny too.

I think though it has been shown that scientists in the distant future may still be able derive the expansion of the Universe by observing distant hypervelocity stars. But they're going to need really big telescopes.
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Old 06-08-2019, 08:43 PM
 
832 posts, read 809,183 times
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Quote:
Originally Posted by Mircea View Post
Ether.

I don't actually believe dark matter/energy exists.



They could be wrong.

I'm sorry, but Hubble is not the end-all-be-all.

In our life-times, we've seen the Universe grow in both size and age, from what we were told in elementary school, high school, college and beyond.

That growth was due to better technology providing more data and a better understanding.

The Universe is probably bigger and older than what they currently believe, and something better than Hubble will prove (or disprove) that.

The whole idea of dark matter/energy is predicated in part on the belief that the observable rotational speed of galaxies and clusters of galaxies is faster than the calculated speed.

Their calculations or observations or both could be in gross error.

Our Sun is a G-Class star. K-Class stars are similar, just a tad cooler. But, the celestial mechanics that result in the formation of G/K-Class stars always results in the formation of 6-12 terrestrial and gaseous planets. Given that there are 10,000 G/K-Class stars within 50 light years of Earth, that's 60,000 to 120,000 planets, but they refuse to believe that. They think planets are rare, when in fact they aren't, and the amount of Space debris left over from the formation of any star is far greater than they're willing to admit.

The point being there's a lot of reasonable explanations for the alleged discrepancies that don't require exotic theories.
To be more precise the rotational speeds of individual stars, gas and dust in galaxies. The speeds of each should be less the farther they are from the center of the galaxy. The observed values do not coorespond to calculated ones. The only way to make the numbers work is to introduce a lot more mass that extends out far beyond the edge of the galaxies. This extra matter has been called Dark Matter. Whether dark matter acually exists is up for debate until someone figures out what it is and finds a way to observe it.

It may be impossible to determine the true size of the universe because how far we can see is limited by "the visible universe". In other words the farthest we can see is the point where the observed speed is less than the speed of light. Beyond that the light emitted there will never reach us.

Another thing is that the farthur out we observe the further back in time the objects are. It is impossible to know what the whole universe looks like at at a given time.

Dark Energy has nothing to do with Dark Matter. Dark Energy was invented to explain why the universe is expanding at a rate faster than previously predicted.

In a way both Dark Matter and Dark Energy are like "fudge factors" to make the theoritical equations fit the actual observed data.
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