BS: Dark Matter

Subject: BS: Dark Matter
From: beardedbruce
Date: 16 May 07 - 12:40 PM

http://www.cnn.com/2007/TECH/space/05/16/dark.matter.ring.reut/index.html


from the article:
""It's really exciting if it's right. But to be sort of convinced of the ring, astronomers would really want to see some independent observations verifying it," Massey said."


But then, lack of knowledge has never stopped Mudcat from discussing something...


(for BillD:)

Does anyone else out there think that this is an interesting "find"?

Subject: RE: BS: Dark Matter
From: mrdux
Date: 16 May 07 - 12:54 PM

bb:

I, for one, think it's fascinating.

michael (a reformed science guy)

Subject: RE: BS: Dark Matter
From: JohnInKansas
Date: 16 May 07 - 12:56 PM

It was predicted by the theories, hence it was an expected find.

It's interesting that someone claimes they've found it.

It will be almost as interesting to see if a few others can agree that it's been found.

It won't slow down the attempts others will make to find others like it - or others a little different.

There's bound to be an argument eventually - and that may be really interesting! (It depends on which teams are playing.)

John

Subject: RE: BS: Dark Matter
From: Amos
Date: 16 May 07 - 12:57 PM

I, for two. I agree with the thoughts expressed by Mister Massey: "Given that dark matter is the most common stuff in the universe, the fact that we know almost nothing about it at the moment is really rather embarrassing."


A

Subject: RE: BS: Dark Matter
From: skipy
Date: 16 May 07 - 12:59 PM

When having turkey, I prefer the dark meat!
Skipy

Subject: RE: BS: Dark Matter
From: beardedbruce
Date: 16 May 07 - 01:03 PM

Amos,

It is something like common sense- SUPPOSED to be everywhere, but no-one every seems to have any.

8-{E

Subject: RE: BS: Dark Matter
From: Peace
Date: 16 May 07 - 02:01 PM

Since I don't know squat about it, and since the people who do know squat say they don't, ("Given that dark matter is the most common stuff in the universe, the fact that we know almost nothing about it at the moment is really rather embarrassing," Massey said.") I will leave now.


Interesting? You bet!

Subject: RE: BS: Dark Matter
From: Peace
Date: 16 May 07 - 02:08 PM

"The existence of dark matter was first suggested in the early 1930's by the Swiss physicist Fritz Zwicky who calculated that the radial velocities of eight galaxies was 400 times greater than that expected by the shared gravity of luminous matter in those galaxies. The explanation given by Zwicky to his extraordinary find was to suggest the existence of what he called "dark matter", or matter which cannot be directly observed but can be inferred indirectly by its gravitational influence on visible matter. Analogously, imagine a caveman, who never saw a modern city, looking at New York at night. Naturally he will assume that New York is just a collection of light sources since all he can see is a variety of bright dots. Just like New York, space has much more then meets the eye."

Neat summary here.

Subject: RE: BS: Dark Matter
From: Q (Frank Staplin)
Date: 16 May 07 - 02:09 PM

It was a dark and stormy night ...

Subject: RE: BS: Dark Matter
From: Amos
Date: 16 May 07 - 02:36 PM

As she was not yet seventeen, her pregnancy was a dark and stormy matter...


A

Subject: RE: BS: Dark Matter
From: MMario
Date: 16 May 07 - 02:40 PM

I don't know why it has taken so long to find a ring of dark matter - there is one around the tub every time we bathe the dog!

Subject: RE: BS: Dark Matter
From: Donuel
Date: 16 May 07 - 02:46 PM

"Previous Hubble observations showed another collision between two galaxy clusters in which dark matter appeared to behave differently."

This refers to the astronomical picture that shows a collision of two clusters. An area of warping (falsly colored blue) infers that dark matter seems to pass unimpeded through a cluster while normal matter is greatly slowed with much more interaction.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 16 May 07 - 03:20 PM

Perhaps the ring was formed after the two black holes in the center of each cluster hit head on.

If so one might have expected a mega dynamic quasar like explosion.

Subject: RE: BS: Dark Matter
From: Bill D
Date: 16 May 07 - 05:05 PM

*grin*...getting closer, bruce (but then, this is a pretty neutral subject)

I, too, think it's fascinating. But it will take a LOT of research to be sure that's what they found. Anything that can't be looked at, and can only be inferred, is kinda hard to pin down.



Now, where's the REST of it?

Subject: RE: BS: Dark Matter
From: Peace
Date: 16 May 07 - 05:20 PM

OK. I realize this is a really good effort to get folks onto topics wherein the arguments won't get heated. (Good on ya, BB.)

So, when God made the universe, did the dark matter matter only half as much when He said, "Let there be light"?

HEE HEE HEE

Subject: RE: BS: Dark Matter
From: Bill D
Date: 16 May 07 - 05:26 PM

God, being all-knowing, and giving mankind the gift of **reason**, knew that we'd realize that "let there be light" logically meant there HAD to be dark to compare it to....ergo...












(I think)

Subject: RE: BS: Dark Matter
From: JohnInKansas
Date: 16 May 07 - 06:13 PM

Actually, "Let there be light" is merely a paraphrase of the actual statement.

The complete text is not currently accessible, but artifacts are being studied to attempt it's reconstruction from the oldest surviving material.

The most commonly cited fragments generally accepted to have survived in form representing the actual statement are summarized at:

Abridged Transcript of the "Light" speech

Note that some of the "words" used in this transcript are not readily pronounced by persons not immersed in the study of the history and meaning of the statement.

John

Subject: RE: BS: Dark Matter
From: Peace
Date: 16 May 07 - 06:32 PM

LOLOL

Subject: RE: BS: Dark Matter
From: BanjoRay
Date: 16 May 07 - 07:59 PM

The dark matter is in fact where God's been hiding all these years.
Ray

Subject: RE: BS: Dark Matter
From: Peace
Date: 16 May 07 - 09:31 PM

OK. I gotta ask a really stupid question.

Earthquakes. Could they be caused by 'shock' waves of sound so low we have trouble registering them? Like waves--caused by BIG explosions--that have travelled through the expanse of time and space (cliche, I know) and have finally hit our planet?

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 16 May 07 - 11:56 PM

"Anything that can't be looked at, and can only be inferred, is kinda hard to pin down."

You mean questions like "What is folk music?"

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 17 May 07 - 02:34 AM

"Could they be caused by 'shock' waves of sound so low we have trouble registering them"


"caused"?

Well the theory (which is not necessarily espoused by the "Design by old guy with a long beard mob!") goes that the tectonic plates are moving relative to each other and 'hang up' for a while until they finally let go, the grinding together of the edges produces the shock-wave.

Occam's Razor - "Do not endlessly propagate unnecessary entities".

In other words - KISS!

Subject: RE: BS: Dark Matter
From: GUEST,Keinstein
Date: 17 May 07 - 03:49 AM

There's lots of dark matter around. It's just that scientists work during the day, so they only see it when it's light. In fact I trod in somne dark matter on the way home from the pub last night. Scientists should get their act together. Put on a night shift, double time and an extra week's holiday. Look at the dark side of the moon, and where the sun don't shine.

Subject: RE: BS: Dark Matter
From: beardedbruce
Date: 17 May 07 - 11:07 AM

"It's just that scientists work during the day,"

Not in the field of astronomy!

And certainly not all of those in other fields- Many of us are working in the dark, most of the time!

8-{E

Subject: RE: BS: Dark Matter
From: GUEST,Keinstein
Date: 17 May 07 - 11:39 AM

Well, astronomers working at NIGHT are looking at the BRIGHT bits innit. If they put the cap back on the telescope they'd see the DARK matter.

Subject: RE: BS: Dark Matter
From: Amos
Date: 17 May 07 - 11:43 AM

Peace:

No.

Shock waves require particle density, no matter how low the frequency, to propogate. And between here and Sol, there just ain't much in the way of particle density.

A

Subject: RE: BS: Dark Matter
From: Peace
Date: 17 May 07 - 12:22 PM

Thank you.

Subject: RE: BS: Dark Matter
From: Peace
Date: 17 May 07 - 12:24 PM

I think Occam may have been fulla shit.

Subject: RE: BS: Dark Matter
From: beardedbruce
Date: 17 May 07 - 12:33 PM

clean shaven shit, anyway...

Subject: RE: BS: Dark Matter
From: Bill D
Date: 17 May 07 - 02:32 PM

A.N.Whitehead offered a corollary to Occam's Razor:

"Strive for simplicity...but learn to mistrust it."
but this corollary is almost unnecessary IF one understands the whole of the Razor:
entia non sunt multiplicanda praeter necessitatem

The fact is, some folks just like embroidering theories.

Subject: RE: BS: Dark Matter
From: Peace
Date: 17 May 07 - 02:39 PM

I agree. I think Occam's Razor is often employed because people don't want to think about it anymore. In many instances, OR makes sense. But every situation is not a place to employ the principle. A good friend--quite brilliant in fact--said when I asked if he believed in God: "No." I wondered why. He replied, "I don't need the complication in my life." Occam had the complication in his life. (Of course, the razor thing was something that had been employed in philosophy before Occam entered the picture.) There are times when I wish folks would just avoid mentioning Occam as though he were an authority. No offense to anyone.

Subject: RE: BS: Dark Matter
From: Bill D
Date: 17 May 07 - 02:59 PM

*grin*..Occam just provided the first real formulation of a basic principle that a lot of people, including philosophers, had sort of understood viscerally.
   Now he is sort of honored by being used as the 'shorthand' reference.

Wikipedia gives a pretty concise history & explanation of the 'razor' and its applications and limitations.

The point is not that we should take some 13th century scholar as an 'authority' on how to to think today, but that some logical principles are so useful and important that we CAN identify them by a historical reference.

Nowadays, folks usually use the more 'earthy' form...K.I.S.S....but it's essentially the same idea.

Subject: RE: BS: Dark Matter
From: Peace
Date: 17 May 07 - 03:25 PM

True, Bill. But some things just aren't at all simple. Something I think shown by the motion of fluids or chaos theory itself. Or human activity. We can reasonably predict what 1,000,000 people will do this year (die, give birth, end up in jail), but it is difficult to predict what ten of those folks will do based on the larger model.

Subject: RE: BS: Dark Matter
From: JohnInKansas
Date: 17 May 07 - 04:30 PM

At the ever popular American Scientist site, the current issue has a nice little article titled "Fat Tails" right at the top that deals with some examples of "statistics" that don't extrapolate between large samples and small samples, in quite unexpected ways. It probably will be of interest only to those with some mathematical curiosity, but is worth a glance.

You could go directly to the article at Fat Tails but then you'd miss the separate article at the first link to Dark Matter Comes to Light.

The latter article is a discussion of how to make pictures for publication of something that can't be seen. Although it's more related to displaying results of general dark matter surveys, and not specific to the "circular" object in recent reports, it may help some who have difficulty visualising the visible depicting of things that are invisible.

Both articles should offer "printer friendly" and .pdf versions for those who need to find a kid to explain them.

John

Subject: RE: BS: Dark Matter
From: beardedbruce
Date: 17 May 07 - 04:53 PM

http://antwrp.gsfc.nasa.gov/apod/ap070516.html

note that the vast majority of objects in this picture are galaxies, NOT stars!

Subject: RE: BS: Dark Matter
From: Stringsinger
Date: 17 May 07 - 05:18 PM

It's astronomically dark fecal matter.   Star Drek.

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 17 May 07 - 11:45 PM

"In many instances, OR makes sense. "

Well, if you start with a strong immutable belief that a certain book must be taken as an exact literary explanation of the creation of what you live in, then things like radioactive dating, etc are unnecessary complications.

Once however you do decide to accept that one - then you end up with enormous confusing complicating intellectual contradictions - William was just trying to make the intellectual processes simpler, and thus less difficult to grasp - So was Galileo... and look what happened to him - 600 years to get his idea formally accepted by the Church...

Subject: RE: BS: Dark Matter
From: Rowan
Date: 18 May 07 - 12:33 AM

John's "some examples of "statistics" that don't extrapolate between large samples and small samples" brought to mind the old notion that most of us have more than the average number of fingers (and eyes. legs, any part of the body that is an integer-rather than integral?).

Cheers, Rowan

Subject: RE: BS: Dark Matter
From: JohnInKansas
Date: 18 May 07 - 03:20 AM

Yes, Rowan, but the objects the article talks about don't even have averages.

John

Subject: RE: BS: Dark Matter
From: John Hardly
Date: 18 May 07 - 09:07 AM

save me a drumstick.

Subject: RE: BS: Dark Matter
From: Bill D
Date: 18 May 07 - 11:58 AM

bass or snare?

Subject: RE: BS: Dark Matter
From: John Hardly
Date: 18 May 07 - 12:14 PM

"...snare?

I'm not going to get caught in that old trap.

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 19 May 07 - 01:47 AM

But aren't fingers integral digits?

Subject: RE: BS: Dark Matter
From: GUEST,Art Thieme
Date: 20 May 07 - 12:12 AM

Foolestroupe,
So is a barre chord actually a digital capo??!!

I'm getting scared of the dark.

Art

Subject: RE: BS: Dark Matter
From: GUEST,Art Thieme
Date: 20 May 07 - 12:13 AM

...for that matter!

Subject: RE: BS: Dark Matter
From: JohnInKansas
Date: 20 May 07 - 04:42 AM

But aren't fingers integral digits?

That would likely be taken as true, provided that they're attached in the usual manner.

Of course the contrasting concept of integer digits is sort of a redundundanancy.

John

Subject: RE: BS: Dark Matter
From: 3refs
Date: 20 May 07 - 05:25 AM

The more we learn, the more we realize just how little we know.

We look out there, in wonder and awe! We try to figure it all out! Look at your surroundings here on earth. How many neighbors, who live a stones throw away, have you never conversed with? See where trying to look at creation might be a bit of a stretch!

Can't see the forrest cuz the trees are in the way!

I think if you can get a grasp on here, out there becomes a history book we can finally read.

Mayan Calander 2012!!!!!

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 20 May 07 - 07:45 AM

"The more we learn, the more we realize just how little we know."

Employ a teenager today, before they grow old and forget evrything!

Subject: RE: BS: Dark Matter
From: Rowan
Date: 21 May 07 - 02:44 AM

Too right, Foolestroupe.
My elder daughter turns 16 on Thursday and the younger becomes a teenager three weeks later.

I figure my Early onset Alzheimers ought to blend perfectly with their adolescence so that I'll instantly forget everything I should ever have noticed in the first place.

A very dark matter.

Cheers, Rowan

Subject: RE: BS: Dark Matter
From: The Fooles Troupe
Date: 21 May 07 - 05:18 AM

Doom, doom-doom, doom,

Doo-oo-oo-oo-oo-oom!

---

It was confusing to have two threads running with the same title, so I combined them. I hope that was the best thing to do. Messages above were from 2007.
-Joe Offer-

Subject: Dark Matter
From: banjoman
Date: 16 Jan 18 - 06:30 AM

I know that there may have been a previous thread somewhere, but I was asked this question by a 10 year old and had a problem answering it.
If the universe is made up mainly of Dark matter and it weighs a lot, then why don't space rockets and satellites bump into it, or isn't it solid???

Subject: RE: Dark Matter
From: Nigel Parsons
Date: 16 Jan 18 - 06:38 AM

BS: Dark Matter

Earlier thread found.

Cheers

Subject: RE: Dark Matter
From: DaveRo
Date: 16 Jan 18 - 07:30 AM

Pretty good: Charlie Dore - Dark Matter

Subject: RE: Dark Matter
From: Acorn4
Date: 16 Jan 18 - 07:50 AM

When I clicked on this I thought it might be a thread on Leonard Cohen.

Subject: RE: BS: Dark Matter
From: Nigel Parsons
Date: 16 Jan 18 - 07:51 AM

From another thread:

Subject: Dark Matter
From: banjoman - PM
Date: 16 Jan 18 - 06:30 AM

I know that there may have been a previous thread somewhere, but I was asked this question by a 10 year old and had a problem answering it.
If the universe is made up mainly of Dark matter and it weighs a lot, then why don't space rockets and satellites bump into it, or isn't it solid???

Subject: RE: BS: Dark Matter
From: Donuel
Date: 16 Jan 18 - 09:06 AM

Hi Nigel, I thought Keb brought back these good ol days.
In the intervening decade a new theory of dark matter black holes has been postulated. If true they would be over 13 billion years old.
Also BHs can be created without a trace or a nova.

One thing is certain in that the rate of BH creation is growing exponentially over time. Dark matter today does not seem attracted to black holes that much. Probably not their type. ":^/

This has major implications imo for the expansion rate of the universe and the balancing forces that maintains space itself.

Things can stretch so much until a sudden state change occurs and the universe converts to a lower energy state. That is 'the end of the world as we know it' spreading at the speed of light.
Some physicists say its inevitable but we'll never see it coming.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 16 Jan 18 - 09:23 AM

It is dispersed as sub-atomic particles and they do not interact with ordinary matter.
It would slip through a spacecraft without any effect on it or any crew.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 16 Jan 18 - 09:27 AM

Hi Nigel, I thought Keb brought back these good ol days.
In the intervening decade a new theory of dark matter black holes has been postulated. If true they would be over 13 billion years old.
Also BHs can be created without a trace or a nova.

One thing is certain in that the rate of BH creation is growing exponentially over time. Dark matter today does not seem attracted to black holes that much. Probably not their type. ":^/

This has major implications imo for the expansion rate of the universe and the balancing forces that maintains space itself.

Things can stretch so much until a sudden state change occurs and the universe converts to a lower energy state. That is 'the end of the world as we know it' spreading at the speed of light.
Some physicists say its inevitable but we'll never see it coming.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 16 Jan 18 - 02:30 PM

Why do you say that about the rate of black hole creation?

Dark matter is attracted to black holes. Gravitationally it is the same as normal matter.

Subject: RE: BS: Dark Matter
From: banjoman
Date: 16 Jan 18 - 04:54 PM

Thanks all. Hope I can translate into 10yr old language, but they are so smart these days. When I did A level physics,( 1960,s) I don't think electricity had been fully discovered.

Subject: RE: BS: Dark Matter
From: Mr Red
Date: 16 Jan 18 - 05:53 PM

There was a "Sky at Night" programme on BBC TV this week, it will be on the iPlayer.

Basically they reckoned intersteller gas made up at least 70% of Dark Matter. They demonstrated the problem of seeing it by analogy:

A fine spray of water particles is hard to see at a distance, but shine a light through it and you see by light scattering.

The cosmic light source is a pulsar, the gas molecules get illuminated. And with enough pulsars around and probably an extrapolation get you to 70%. Gasses are not necessarily evenly distributed.

Subject: RE: BS: Dark Matter
From: keberoxu
Date: 16 Jan 18 - 06:20 PM

Made me think of Philip Pullman,
but that's His Dark Materials, yes?

Subject: RE: BS: Dark Matter
From: Donuel
Date: 16 Jan 18 - 11:26 PM

Keith yes black holes will eat dark matter but there does not seem to be halos of dark matter surrounding black holes. We can't see it. We do assume huge amounts of neutrinos escape. There is gamma ray evidence from Andromeda that its central black hole is eating something.
We do not know if dark matter gravity is in fact equal to baryonic gravity or not. The only evidence we have of dark matter is gravitational lensing observations and cohesive galactic disc rotation. So we make assumptions.

For myself a good place to start is 'where does/could dark matter come from'.
Some think it came almost immediately after the big bang. THE BIG BANG IS JUST AN ENTROPY EVENT where a highly energetic whole goes to a lower energy state and spreads out, I claim it came much later.
Those who think it came into being quickly before inflation think dark matter is like smithereens of microscopic pieces of black hole density particles. (but they don't interact and grow?)

*I claim dark matter came from the annihilation of baryonic matter charge and spin with opposite anti matter at a ratio of a billion anti matter particles to a billion and one positive matter. This could be how normal matter got an advantage and why we see a universe of normal matter. Everything else turned into energy and the new residue of annihilation energy that reconverts to matter and we now call dark matter.

WHAT IF there were unannihilated anti matter pockets that repelled collision. It might be the pockets of empty space that are usually 20 light years across that has an anti gravity and is acting like the repelling dark energy, as space expands, the larger regions of anti matter continues to repel more like an accelerated push.

(you would think something would have set off an antimatter explosion by now in these seeming empty regions.)

A third assumption about dark matter is that it does not exit. Instead gravity is not a fundamental force but is an emergent force like temperature comes from friction. a trick of gravity propagates what seems like dark matter, -Van Der Linde theory

Your best question is why would the rate of BH creation increase?
must wait = its a doozy.

Subject: RE: BS: Dark Matter
From: Mr Red
Date: 17 Jan 18 - 03:51 AM

average number of fingers

good old Dubya made a speech about throttling Saddam Hussein where he said he had 10 fingers.

I only manage 8, as opposed** to two thumbs. Dodgy ones these days.

** 8-)

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 17 Jan 18 - 04:31 AM

there does not seem to be halos of dark matter surrounding black holes. We can't see it.

It is invisible, but it is there (if indeed it exists.)

. There is gamma ray evidence from Andromeda that its central black hole is eating something.

Matter is falling in, as in all supermassive black holes at galactic centres.

Your best question is why would the rate of BH creation increase?

Who says it is?

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 17 Jan 18 - 02:08 PM

Personally I am more an more attracted to modified gravity theories, of Milgrom, Bekenstein, Mannheim and others. But I do not know of Van der Linde, are you sure you have the name right Donuel?

Dark Matter and gas should not be confused. In conventional theories (i.e the ones Keith is talking about) dark matter is collisionless, gas is viscous. Pulsars can illuminate gas, yes, but not cold dark matter.

Like others I am unsure why it is said on this thread that the rate of black hole creation is increasing. Donuel, do you have a reference for this statement?

Subject: RE: BS: Dark Matter
From: Donuel
Date: 17 Jan 18 - 03:25 PM

An even better question is why would BH creation remain static?

Let there be no mistake, the who is me.

Dark Matter is likely to be a combination of primordial matter AND the product of annihilation physics during inflation.
Owing to the observations of supermassive black holes very early in the universe, there is speculation they were formed by an abundance of dark matter since there wasn't enough time for baryonic stars to collapse and merge to super massive status. Many think the properties of dark matter black holes are different than BHs today such as having lower temperatures.

Now, regarding black holes and dark energy;
I have held for over a decade that there are far more BHs than the largest estimates ever made. This is being born out by many recent findings. The BHs that broadcast their existence like quasars, pulsars, GRbursters, Super Nova creations, collisions, galaxy centers, rogue, etc. that are visible with radio and optics, are actually the minority of the true number of BHs. In advance of the james Webb findings I will assert their are hundreds of supernovas from stars over 23 solar masses every night in our sky.

Our early estimations were wrong.
So there are far more BHs to begin with but I speak of an accelerated rate.

I found a question regarding a 'strange correlation' and a 'point' in time when the universe just began its current acceleration.
Finding the point of acceleration is done by using red shift values on one end and 'pictures of the early universe on the other end.
The first shift in expansion began when the universe was between 5 and 6 billion years old.

The mass of all the black holes when the universe was 5.5 billion years old was a turning point. This where a leap of thought is required similar to string theory. We know energy can not be created or destroyed. It goes someplace. Inside each Black Hole is a singularity where our laws break down. now hold on.

Black Holes are said to evaporate over time, says Hawking. I defer.
A Black Hole can grow in mass and volume, it can send energy out AND it can send energy in.

Where could it go. It could transform into space energy, which is HIGHLY energetic. A black hole can be a forge here energy and mass can be transformed into its counterpart, space.

From here you should be able to see the rest of my thinking.
This is about the 5th time I have explained my postulate here.
I reject all early verdicts. All that is changed is my improved ability to put forth this theory in lay terms.

If you ask what is the exact rate of increased BH formation you have missed the point. But it will correlate to the rate of acceleration of space. The point is simply describing the source of dark energy, the greatest enigma of our time.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 17 Jan 18 - 03:34 PM

David I do not agree with Verlinde anyway.
Keith your tone is abrupt. Are you itchin fer a physics fight or thought?

Subject: RE: BS: Dark Matter
From: Donuel
Date: 17 Jan 18 - 03:48 PM

We can never see a string and we will never see a space forge at a singularity.

Compared to ideas that a neutrino can grow to galactic size or emergent gravity is holographic based, my idea is simplistic in the other direction. I'm not fighting for tenure so I follow my emergent dreams.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 18 Jan 18 - 02:43 PM

Read nothing in to my tone Donuel.
Not fighting just chatting, but you say things that demand to be challenged.
A Black Hole can grow in mass and volume,

They have no volume, and gain mass only by swallowing matter.

Dark Matter is likely to be....

Says who? There is no consensus on this or even that it exists!

Subject: RE: BS: Dark Matter
From: Donuel
Date: 18 Jan 18 - 05:51 PM

By volume I meant that BHs can grow in surface area.

The most challenging BS is imagining that the singularity sends energy some where. I have no idea if this evaporation from the center of a BH exits. If it did It would amount to a loss of mass in BHs that aren't eating. I know of no such data
I gravitate to dark matter coming from the annihilation event only because there is no other event that involves such gargantuan amounts of matter and energy except for the earliest events of the big bang.

If everyone offered some explanations of these two mysteries we would probably still be wrong.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 19 Jan 18 - 05:25 AM

By volume I meant that BHs can grow in surface area.

They have neither.
If you mean the event horizon, its area and volume is determined by the mass of the BH.

I have no idea if this evaporation from the center of a BH exits. If it did It would amount to a loss of mass in BHs that aren't eating. I know of no such data

Hawking radiation leads to the evaporation of BHs. I believe that is now well established.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 09:24 AM

"information is lost in a BH"
S.Hawking

He has been wrong before.

Its good you mention Steven. It proves you listen. Virtual particles accounting for all mass loss in BHs is still problematic as well as being possible.

Sometimes various ideas are not mutually exclusive. Sometimes they are. Measurement and experimentation is needed to sort it out.

Its a bit pedantic to kvetch over volume, surface area and event horizon. You conceptually understood in the first place.
Perhaps you prefer a discussion that will not be understood by lay people but more likely you may not understand the big picture of my speculation which is as novel today as Fritz Zwicky was in his day.

Could you put it in your own words yet?
Do you have ideas/explanations of your own or is it strictly a collection of other people's hypothesis? not that there is anything wrong with that...its just not creative.

its mainstream. Look how many mainstreams we have had in 300 years.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 10:58 AM

In truth BHs lose mass from more than Hawking radiation.

Some think a loss of BH mass comes from gravitation binding energy or another factor.

m=E/c2, the mass does go someplace https://www.forbes.com/sites/startswithabang/2016/12/03/ask-ethan-how-do-gravitational-waves-escape-from-a-black-hole/#18a3f3051
This question has puzzled me for a long time. Articles about LIGO discovery state that some percentage of black hole merger mass was radiated away, leaving a resulting black hole smaller than the sum of the original mergers. Yet it is accepted that nothing escapes black holes. So my questions are: how was energy radiated from black hole mergers? Do gravitational waves turn into energy from mass and propagate outwards??

Or could it be a cosmic forge of mass to space conversion?
possibly.
Over the life of the universe a cumulative 5% 'push' from more and more black holes could be the dark matter push.

To me it is a clever question but we have more questions than answers.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 19 Jan 18 - 12:54 PM

It is a fact that a BH has zero volume and area.
It is a fact that the volume and area of its event horizon is determined solely by its mass.

In truth BHs lose mass from more than Hawking radiation.

says who?

Do you have ideas/explanations of your own

No. I do not have the knowledge or the intellect.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 02:17 PM

says who
says every scientist who understands LIGO. (3+2=4.7)
Sorry I didn't know you needed to get more acquainted with Saul Perlmutter. Better call Saul

Many discoveries are called inspired when they go beyond knowledge and intellect. Linear minds look at such spooky events with a narrowed and jaundiced eye.

Whats curious to me is that I have harbored these notions before there was LIGO, before the accelerating universe, before a clearer census of BHs.

Arr, Thinking b a proud pastime she is.
She's not all conscious, Arr
but she's a fickle mistress.
She's not just a toss in the Wiki alas

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 19 Jan 18 - 04:37 PM

Saul Perlmutter is an expert on Supernovae, type Ia in particular, and using these to determine the geometry of the universe, for which he shared the Nobel prize. He is also an expert on high redshift galaxy clusters. He has not, to my knowledge, and, more pertinently, to the knowledge of the NASA Astrophysics Data System, published any refereed papers on black hole mergers as detected by LIGO. It isn't his subject.   

You are probably referring to a paper by B.P Abbott et al., which states that in a merger of two black holes of 36 and 29 solar masses, three solar masses were radiated away as gravitational radiation. This apparently is consistent with standard general relativistic models, but this gets to be seriously difficult stuff and beyond my mathematical capabilities.

The end product of all this is a rotating (Kerr) black hole, and when you have rotation I think the area and volume of the event horizon depends upon the rotation as well as the mass, though what Keith says is true for a non-rotating (Schwarschild) black hole. The maths are very hard though. Make it magnetic or charged and then it gets even worse.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 05:33 PM

Good. The contribution of Saul's group, that I refer to, is the measuring and discovery that the expansion of the universe is ACCELRATING against all intuitive odds.

Very soon with new telescopes we will find a hundred times more Novas Perimutter could find in one night, every night.

What is pushing everything progressively faster is a mystery, so we arbitrarily call that 'push' Dark Energy. This is the trillion dollar question that is puzzling Modern Physics, among other things.

How could Black Holes provide that push, as I claim beyond all intuition , and be a source of dark energy???*


*That's what my idea is all about.*


Dark matter is another mystery and an interesting component to types of matter most abundant but transparent.

We all can take a stab at mystery solving. My wife does Murder Mysteries.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 05:58 PM

Rotating Kerr BHs are fascinating, although I believe they all rotate. Some have a region inside in which centrifugal forces nearly balance the in falling/gravitational forces. Inside the event horizon this balanced region could be thought of as another boundary separating an inner black hole from the outer black hole.

Some believe the enormous magnetic forces and such create a paranormal force akin to alternating current but rather alternating existence and non existence. I'm not saying it does but this is one of the notions floating around out there by a self promoter by the name Nassim.

Thanks for letting me carry on this chat about my hobby without religious objection like last time.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 19 Jan 18 - 08:23 PM

Earlier in the thread I knew Peace, from Alberta, before he was Peace.
He had cosmologist acquaintences. He's a good folksinger.

Um, regarding dark matter the issue of whether it interacts with itself is critical in knowing if it might come in more complex forms similar to baryonic matter.
So far we think it interacts with itself a bit. How much it interacts is still a 'bit' uncertain.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 20 Jan 18 - 07:18 AM

entia non sunt multiplicanda praeter necessitatem

As well as the oft repeated Razor there is the factor of taking too strict a technological path to understanding that risks missing an important parameter. The magic of life.
_
|

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 20 Jan 18 - 09:33 AM

So your idea is that BHs are driving the acceleration.
Based on what?
Does any astro/quantum physicist share your belief?

Subject: RE: BS: Dark Matter
From: Donuel
Date: 20 Jan 18 - 01:33 PM

As with most inventors we are kinda right for the wrong reasons until everyone chips in to improve the engineering.

There is one guy in NZ who independently comes close. The types of BHs that have 5% push have to be colliding, or maybe super massive. I don't know. BHs are kinda tight lipped.

Why do you care?

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 21 Jan 18 - 04:48 AM

Why do you care?

The subject fascinates me and I thought you might know something that I have missed.

Subject: RE: BS: Dark Matter
From: Black belt caterpillar wrestler
Date: 21 Jan 18 - 06:06 AM

So if the universe is expanding at an ever increasing rate presumably, given enough time, a galaxy that is far enough away will drop out of sight as it will be moving away from us at a speed beyond the limit of light speed.
Moving on from this, at some point we would only be able to observe our own galaxy, then our own solar system (hypothetical as it would have aged to destruction long before this).
Eventually you wouldn't even get light from the sun.

I know that a lot of other things would happen to stop this scenario but basically, if the universe expansion accelerates away do we reach a point where the entire universe is expanding beyond light speed at a local level?

Robin

Subject: RE: BS: Dark Matter
From: Mr Red
Date: 21 Jan 18 - 06:55 AM

dark matter is collisionless

I thought the explanation was that dark matter was/included baryons. Pulsars were so intenses (and focused) they reacted with baryons. Or enough of them to show something we can detect. The totals are thus, presumably, extrapolated.

But what do I know? Only what those wot do know tell me on TV.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 08:13 AM

Ah Keith, I read your 20,000 posts ":^/ and discovered you do not suffer fools lightly and are quite forthcoming. You are not an Amazing Randy but you are an amazing Keith.

The limits of observable space will be brought into view with an infra red detecting telescope to see the red shifted outer regions. Light speed is not expected to get special dispensation.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 08:33 AM

In the pissing contest of who knows more, knowing what to look for and why is bigger.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 09:23 AM

be part of the crowd sourcing about dark matter https://www.sciencedaily.com/releases/2018/01/180110141323.htm


Getting closer in my book https://www.sciencedaily.com/releases/2017/12/171218131317.htm

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 09:44 AM

Neither dark matter or dark energy needs to exist. Remember we made it up to explain a mystery. Every month there are those who chime in and say DM and DE do not exist. https://www.sciencedaily.com/releases/2017/12/171214100859.htm

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 21 Jan 18 - 12:15 PM

The most distant galaxies we observe are moving away from us at faster than the speed of light, and always have been see here.

And various other papers, by the same and other authors.

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 21 Jan 18 - 12:23 PM

Dark matter in the "standard" cosmological models is collisionless. Baryons are not dark matter in this sense. Very dim, and very hard to see, especially if they are at a temperature and density where they do not emit much detectable radiation, but they are not, as cosmologists understand, dark matter.

However some cosmologists (Ben Moore is one) write papers on collisional, strongly self-interacting dark matter. It seems to have dropped out of fashion in the last ten years though

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 21 Jan 18 - 12:30 PM

Nothing can move through space faster than light, but the expansion of space can exceed that.
Light from distant galaxies can be seen but red shifted.
The radiation from the big bang itself can be observed, but it is red shifted into the microwave range.

Pulsars were so intenses (and focused) they reacted with baryons.

That is just meaningless.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 01:25 PM

Space expansion is not hand cuffed by the speed of light over distances. As the article says General Relativity is not contradicted.

We're so sorry, Uncle Albert, we didn't mean to doubt your Math today.

Albert if you had not confused us with your cosmological constant flip flopping, superluminal factors might not still be called into question.

Dave and Keith are in a sense both right but Dave is 'righter'.
Dave, if memory serves, was it you who posted a year ago that you once attended a lecture by Zwicky? They say he was a disagreeable character.
We recently lost Vera Rubin.

don't get me started about space properties and how they seek equilibrium. BTW the time cone diagrams* speak my language. I do not think in math language. Or even English that well.

*much to study there

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 21 Jan 18 - 01:59 PM

The reason that people think, wrongly, that nothing can move faster than the speed of light, relative to an observer, is that they are considering only special relativity, not general relativity. That is the subject of the linked pdf file. Keith is right about the redshift, but the relationship between redshift and velocity is complicated, and here general relativity is needed.

This statement:

"Nothing can move through space faster than light"
is a fundamental misconception, even in special relativity. Things do not move through space, they move relative to each other. This is what Michelson and Morley showed.


Yes, Donuel, I did once attend a lecture by Zwicky, I would not say that I knew him. I have heard that he could be difficult. In fact he published a catalogue, which we knew as the "red" Zwicky catalogue, as opposed to the better known "blue" one. Its here. The second section makes interesting reading, he criticises in print virtually every one of his contemporaries.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 21 Jan 18 - 02:42 PM

I knew I should have said special instead, but I'm playing fast and loose. I should tighten up the loose screws and get back into cosmology after a recent hiatus. After all, the Webb is coming as well as McDonald's and more
Thanks for keeping me honest, I foresee memory problems. I left a bag of deli at the checkout. That's not like me.

Subject: RE: BS: Dark Matter
From: Mr Red
Date: 22 Jan 18 - 03:42 AM

That is just meaningless.

tell that to "the Sky at Night" presenters. They explain by analogy.
They chose water droplets sprayed, and an LED torch.

A clumsy phrase, but:
intensity has to be strong enough to be detectable with the equipment/methods available and inevitably the detected signals have to be better than noise. Pulsars sweep across the void, thus signal/no signal is a lot easier to separate, especially if it synchronises with that seen from the pulsar electromagnetically.

All I understood was the analogy. Try it yourself.........

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 22 Jan 18 - 04:11 AM

I am not sure what the sky at night presenters said, I don't watch it much since Patrick Moore died. But Pulsars consist of baryons, a strong magnetic field, and the interaction of these lead to radiation (radio, optical, x-ray, gamma-ray). Thats what 99% of astrophysicists believe anyway.

There has been a theory that pulsar emission is due to mutual annihilation of heavy dark matter particles, leading to positrons, electrons and other particles. But I don't think many people believe this.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 22 Jan 18 - 04:25 AM

Things do not move through space, they move relative to each other.

Light moves through space at light speed. Light speed is independent of the velocity of any observer.

I watched that thanks.
It was not about, "Pulsars were so intenses (and focused) they reacted with baryons." which makes no sense.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 22 Jan 18 - 04:28 AM

Sorry.

Things do not move through space, they move relative to each other.

Light moves through space at light speed. Light speed is independent of the velocity of any observer.

tell that to "the Sky at Night" presenters. They explain by analogy.

I watched that thanks.
It was about detecting non-ionised gas.
It was not about, "Pulsars were so intenses (and focused) they reacted with baryons." which makes no sense.

Subject: RE: BS: Dark Matter
From: Mr Red
Date: 22 Jan 18 - 07:51 PM

Light speed is independent of the velocity of any observer.

Oh there are some heretics that are starting question such constants, in order to explain the accelerating expansion of the universe and inflation. Maybe the maths is a little shaky so far - but they are working on it.

non-ionised gas

wot? Stuff we can't see? except by the lensing effect? like dark matter?

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 23 Jan 18 - 04:29 AM

We can see non-ionised gas very well, notably non-ionised hydrogen via the 21cm line which is a transition between two hyperfine levels.

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 23 Jan 18 - 04:40 AM

Watch the programme again. http://www.bbc.co.uk/programmes/b09mj749

This is cold gas that needs to be illuminated to be detected.
They used radiation from distant quasars and looked for absorption.
They were looking for the missing baryonic matter.

Subject: RE: BS: Dark Matter
From: David Carter (UK)
Date: 23 Jan 18 - 04:54 AM

I didn't see it, as I said above I rarely watch it since Patrick died. Its a shadow of its former self. So they were looking for the 21cm line in absorption then?

Subject: RE: BS: Dark Matter
From: Keith A of Hertford
Date: 23 Jan 18 - 05:58 AM

Presumably, but they did not go into such detail. They preferred to do the little demo of shining a light on a spray of mist just to show it being made visible. (This by an astronomer involved in the project.)
Patrick Moore would have given us the details. It has been really dumbed down.

I linked to the prog, and it is in the first few minutes.

Subject: RE: BS: Dark Matter
From: Donuel
Date: 25 Jan 18 - 10:03 AM

Outside the UK I am not allowed to watch the show.

It has been eloquently explained to me that dark matter is like the twigs, branches, limbs and trunk of the tree of the universe. The leaves that cling to the tree are only the relatively light weight normal matter that we can see.

We can not see the wood and perhaps the wood can not see the leaves because the nature of space or the nature of matter does not allow it, but the tree stands.

The visible universe is composed of particles that are realized mathematically in whole numbers in their properties and spin but dark matter may be measured only in relative fractions.

That fractionalized particles are allowed to slip by and through our familiar matter and itself, leaving only gravity as a mutual interaction is a HUGE clue. Now all we need to know is what that means and by the way, learn what gravity really is.