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Dark matter matters

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- Wed, 09 Nov 2016 03:09:08 EST zHoQtF+M No.56645
File: 1478678948074.jpg -(23713B / 23.16KB, 259x450) Thumbnail displayed, click image for full size. Dark matter matters
There's 10 times more matter in the universe than we thought:
http://blogs.discovermagazine.com/d-brief/2016/10/13/the-universe-is-20-times-more-vast-than-we-thought/#.WCLTmjU2thE

A natural law for rotating galaxies:
http://www.physicscentral.com/buzz/blog/index.cfm?postid=5308541299875990673

And finally, matter causes entropy displacement which accounts for the dark matter effect:
https://arxiv.org/abs/1611.02269

TL;DR, we found our missing mass, we can see that rotation speed varies with the amount of visible matter, and with a better understanding of gravity, the whole concept and purpose of dark matter is bunk.
23 posts and 5 images omitted. Click View Thread to read.
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George Herbig - Tue, 28 Feb 2017 21:08:22 EST 7jcVAyVz No.56845 Reply
>>56843
If a0 is equal to the speed of light divided by the radius of the universe, since the radius of the universe is equivalent to the time since the big bang and thus always increasing, presumably this also means the acceleration constant decreases overtime, which means the same amount of force creates more acceleration, right? (thus accelerating expansion) is this an intentional aspect of MOND? Why didn't they predict an accelerating universe beforehand if so?
>>
John Bahcall - Wed, 01 Mar 2017 19:11:28 EST e0oA2mYt No.56846 Reply
>>56843
Wrote a big response but the board swallowed it twice. Milgrom is talking shit, MOND doesn't bridge anything with the largest scales. It fails if you look at anything beyond galaxies. Galaxy clusters, Milgrom admits you need dark matter. Standard cosmology needs dark matter for structure formation but MOND doesn't do structure formation correctly at all, the extra gravity fucks things up. Lastly there is no MOND cosmology, previous attempts to predict the cosmic microwave background were abandoned after they became incompatible with the observations. The only thing MOND does well is galaxies which it was designed to do, it was a model to fit the data, not derived.

Lastly the radius of the universe is a number derived from cosmology, if you change the cosmology to MOND it's not the same. The point about a_0 makes no sense.

>>56845
MOND makes gravity stronger on large scales so that would increase the pull of gravity between galaxies, increasing the deceleration. MOND doesn't have a cosmology so it can't really make these predictions.

Europa Mission

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- Thu, 18 Aug 2016 23:04:09 EST Y3T9nNnZ No.56318
File: 1471575849136.jpg -(65153B / 63.63KB, 320x380) Thumbnail displayed, click image for full size. Europa Mission
Anyone else hyped for the Europa mission?

https://www.youtube.com/watch?v=GqTaDCt_F1Y

The US gov't has given NASA $30 millon to go poke around up there. They're gonna try to scoop up ejecta and see what's in it. I haven't been this interested in a mission since the Titan lander.
13 posts and 2 images omitted. Click View Thread to read.
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Astrobiology Student - Wed, 23 Nov 2016 16:14:22 EST UuJsarOA No.56671 Reply
I am! In fact, my Astrobio class had to do mission proposals for a few bodies to search for potential life. My group got Europa, so we came up with the porbe part of CLIPPER that congress asked for. Yes NASA is doing their own that hits the counsel next moth, but its a school project. Let me know if anyone is interested in the presentaton!

Teaching an astronomy class

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- Tue, 24 Jan 2017 17:29:35 EST CtuYLr3e No.56766
File: 1485296975966.jpg -(27754B / 27.10KB, 300x300) Thumbnail displayed, click image for full size. Teaching an astronomy class
So next week, I have been given the opportunity to teach astronomy (sadly only stars and galaxies) and I need to add some stuff to it. I could go as hard as I want on these freshmen, so what should I include?
8 posts omitted. Click View Thread to read.
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Joseph Taylor Jr. - Fri, 10 Feb 2017 20:16:33 EST 4yc+FRR6 No.56782 Reply
1486775793366.jpg -(719456B / 702.59KB, 1920x1200) Thumbnail displayed, click image for full size.
>>56767
That just sent me on a fun little side quest, thank you.
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Joseph-Louis Lagrange - Thu, 16 Feb 2017 12:33:23 EST M/g1akbS No.56786 Reply
Well, OP, How did it go??
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George Gamow - Thu, 16 Feb 2017 22:51:43 EST U3oyeBRN No.56787 Reply
1487303503131.jpg -(216290B / 211.22KB, 1920x1080) Thumbnail displayed, click image for full size.
>>56766

Random Space Fact youtube videos from Dr. Bruce Betts


Aliens

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- Sun, 16 Mar 2014 20:44:47 EST Jzd78Ub0 No.53216
File: 1395017087604.jpg -(188698B / 184.28KB, 1200x1200) Thumbnail displayed, click image for full size. Aliens
Yo guys. I just had an opifany or what you call it(english is not my first language), if you consider that ufos really exists and the are flying in the sky all the time but why wont they communicate? Then it hit me, we would have done the same, using Rovers! Basically the ufos we see are probably machines flying about and taking pictures and samples of earth. They dont care that we see them, they obviously treat us as beings not worthy to be spoken to. I think its kind of creepy
55 posts and 4 images omitted. Click View Thread to read.
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Kip Thorne - Thu, 02 Feb 2017 03:39:11 EST 10QI3ruX No.56776 Reply
>>56771
Gonna have to agree, nb. No bueno. Was a nice read and all but I'm not gonna turn around and just start speculating wildly. Not that it isn't fun.But still. There is no way to put together an alien mind other than wild speculation. So there's not much to it as is.
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Friedrich Bessel - Fri, 10 Mar 2017 12:22:11 EST bbe1VMqZ No.56856 Reply
1489166531731.jpg -(1201438B / 1.15MB, 2880x1800) Thumbnail displayed, click image for full size.
Well while we no-bump it back to oblivion maybe we should post some pictures.

Gas Station

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- Sat, 17 Dec 2016 00:07:43 EST 3JvngLEe No.56726
File: 1481951263097.jpg -(106773B / 104.27KB, 720x480) Thumbnail displayed, click image for full size. Gas Station
Right now, I'm working on opening a gas station in low orbit around the moon, mostly refueling for interplanetary & deep space exploration. It'll have mechanics on site, parking on the dark side, though a bag of doritos will be $70 and a diet coke will be $14, you'll thank me when you come through. The air force 109 airlift is testing our tech in their fuel depot on the south pole. So I'm still going to come back to earth quarterly to visit the black bear sanctuary that I work at, but they've been getting so used to human food that they're getting pretty aggressive when I see them. Accually I've been pretty good about being able to chase bears out of the front yard, just by waving a broom and yelling, but my parents were out there the other day and ran when they saw our bear, and the little guy chased them. That really gave my parents a shock!
So, tldr; space won't kill me, the planet won't burn, we'll just leave it to the bears and other fluffy animals.
3 posts and 2 images omitted. Click View Thread to read.
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Stephen Hawking - Sat, 14 Jan 2017 23:54:55 EST veR+j0aW No.56759 Reply
hey man I'll take a pack of zigzag blues, and a lighter too.

Directly Imaging Planets

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- Sat, 12 Nov 2016 10:31:11 EST L+GCCa0j No.56654
File: 1478964671170.jpg -(25943B / 25.33KB, 577x619) Thumbnail displayed, click image for full size. Directly Imaging Planets
Hey guys. Good Morning. We can see other planets directly now.

http://www.universetoday.com/131903/princeton-team-directly-observes-planets-around-nearby-stars/

https://youtu.be/tbu1l672uLc?t=2171

Now we can start getting spectra and figuring out what's out there.
1 posts omitted. Click View Thread to read.
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Heinrich Olbers - Mon, 14 Nov 2016 08:54:36 EST 1q2X8R/n No.56656 Reply
>>56654
This news is really exiting, and im glad you posted this but that video is private you massive wonk
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Edmond Halley - Sun, 08 Jan 2017 06:18:31 EST LnHMc7oC No.56750 Reply
>>56658
damn they're all just trying to sound smarter than each other and it's kind of taking away from learning about the whole thing


Kessler syndrome, ablation cascades?

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- Mon, 14 Nov 2016 09:20:43 EST 1q2X8R/n No.56657
File: 1479133243854.jpg -(102142B / 99.75KB, 640x640) Thumbnail displayed, click image for full size. Kessler syndrome, ablation cascades?
Our planet has a steadily growing shell of orbital debris. This space junk is most concentrated in low earth orbit band. Currently there are somewhere over 1,100 active Gov't and private satellites in orbit, as well as over 2000 that have ceased functioning.
That's just the satellites, as it is estimated that there are over 600,000 pieces of bullshit between 1 and 10 CM just waiting to blow a bunch of holes in any given mission.
Now, if a large enough object were to collide in LEO, or some kind of explosion, these debris objects will begin colliding, creating shrapnel, and impacting MORE objects in a runaway feedback reaction.
This gives us a number of problems, the first being that it totally kills any launch viability for the foreseeable future as well as destroying all the satellites we already have in orbit. The other major problem is that as these thousands upon thousands of objects get kicked around much like atoms in a nuclear chain reaction, a good number of them will de-orbit and enter earth atmosphere causing heating due to air friction. That is bad for obvious reasons.
So /sagan/ how do we take preventative actions against this? Do we even need to worry? what would a post-cascade earth be like?
4 posts omitted. Click View Thread to read.
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William Fowler - Wed, 16 Nov 2016 13:32:50 EST YHjXylC8 No.56663 Reply
1479321170646.jpg -(113024B / 110.38KB, 900x506) Thumbnail displayed, click image for full size.
>>56661
I wanted to like that so much just for the realistic setting, but holy fuck the dialogue, characters, and unnecessary cutesy Japanese shit randomly crammed in is just too cringeworthy.
It's just highschool drama, but japanese and in space.
>>
William Lassell - Sun, 20 Nov 2016 04:15:45 EST tQX5ylFX No.56664 Reply
>>56663
the high school shit gets real BTFO later on. it's part of the arc deal with it for a few eps
>>
Mike Brown - Mon, 21 Nov 2016 10:03:54 EST 89x/mOqK No.56669 Reply
lookin pretty clean on google maps

Black hole instead of a planet x?

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- Mon, 17 Oct 2016 18:06:57 EST eY06FJul No.56529
File: 1476742017066.gif -(1621583B / 1.55MB, 277x283) Thumbnail displayed, click image for full size. Black hole instead of a planet x?
Wouldn't it be more likely that a [stationary?] black hole is accounting for the gravitational effects thought to be responsible by planet x?
9 posts and 3 images omitted. Click View Thread to read.
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William Lassell - Thu, 03 Nov 2016 16:21:01 EST OXINl/7g No.56617 Reply
>>56529
No, because black holes are rarer in the universe than planets, and a black hole with a small enough mass to cause those effects but without eating the rest of the Kuiper Belt and Oort cloud would be pretty hard to form in the first place. And if it did form, the supernova that caused it would have blasted the rest of the solar system to bits.

MOTHERFUCKING ALIEREMS!

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- Fri, 28 Oct 2016 17:32:07 EST rszf0FN0 No.56560
File: 1477690327717.gif -(97224B / 94.95KB, 400x332) Thumbnail displayed, click image for full size. MOTHERFUCKING ALIEREMS!
I can't believe no one has posted this yet:
http://www.techtimes.com/articles/183699/20161025/evidence-of-alien-life-2-scientists-say-strange-signals-from-stars-are-from-alien-civilization.htm

TL;DR: We looked at a bunch of stars and found 234 -- that's right, two-hundred and fucking thirty fucking four -- stars that appear to have aliens trying to contact us with optical beams.

Go nuts.
5 posts and 1 images omitted. Click View Thread to read.
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George Hale - Wed, 02 Nov 2016 23:34:33 EST 6+AQCLDz No.56613 Reply
>>56610
Agreed, probably more likely it's a yet-to-be understood stellar phenomenon, I mean would aliens seriously spend the time and resources necessary to modify STARS just to send messages? There has to be more efficient methods of stellar communication than modifying an entire fucking star. Like just the amount of engineering to construct a device able to modulate a stars light output seems retardedly complex for communication
Thy being said, maybe it is aliens and the fluctuations in signals has to do with some sort of Dyson sphere like device, not ruling it out. Just saying that aliens are PROBABLY not trying to talk to us by fucking with stars' outputs
>>
Henrietta Levitt - Thu, 03 Nov 2016 19:37:16 EST rszf0FN0 No.56621 Reply
>>56613
Ways to change the spectral qualities of a star:
-pass a prism in front of it
-pass a planet with a spectrally modulated atmosphere in front of it (fancy prism.)
-drop mass with a different spectrographic profile than hydrogen or helium into it
-ignite mass with the desired spectrographic profile with a probe in the photosphere
-like I said before, just send a laser beam with different spectral properties in the same direction as photons from the star are travelling
All of those things would be trivial for a 1K civilization. Does that mean it is aliens? No. But we can't rule it out just because the method seems exotic. It might be hugely practical. I mean, the only thing they can see about our system is the star too, right? If we wanted to send them a message, and knew nothing about whether they are looking for radio signals or anything, the one thing we know they can see about us is our star, so if it can be used to send a message, why not?

If you flush a toilet

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- Thu, 20 Oct 2016 18:56:39 EST P9AJW3+2 No.56545
File: 1477004199582.jpg -(44211B / 43.17KB, 400x300) Thumbnail displayed, click image for full size. If you flush a toilet
In the northern hemisphere vs the Southern Hemisphere will the rotation be different? / how is this effected by these new low flow toilets?

>side note thanks a lot Al Gore now when I go to del taco I have to flush like 20 times... thanks a lot
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Edward Barnard - Sat, 22 Oct 2016 20:55:52 EST Kz5Q207u No.56550 Reply
Shit, didn't see that someone already said the last bit of my post in this post:
>>56547
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Joseph Taylor Jr. - Sun, 23 Oct 2016 23:44:22 EST u7UMnSpi No.56553 Reply
i just hope that the poop goes away

Is colonizing space really a good idea?

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- Thu, 13 Oct 2016 22:44:38 EST kkqIA5n0 No.56515
File: 1476413078998.jpg -(228458B / 223.10KB, 1161x480) Thumbnail displayed, click image for full size. Is colonizing space really a good idea?
There are more than enough resources on Earth to feed and cloth and house the entire world population several times over, but people are still starving and homeless due to our greed and incompetence. We can't make phones that don't blow up or cars that don't drive themselves into a wall. We're still dicking around with fossil fuels and nuclear reactors and steam turbines when we have a natural self-sustaining fusion reactor in the sky that could power the whole planet for millions of years if we just put more research into making better solar cells and superconducting materials and large-scale energy storage. With all our intelligence and resources, we can't make shit work on a planet that gives us everything we need, how the hell are we going to survive on a hostile world where just making food to eat and water to drink and air to breathe is a massive costly endeavor, and one tiny malfunction in our machines will result in horrible catastrophe and death? Is mankind really ready to live in space?
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John Wheeler - Mon, 17 Oct 2016 16:56:39 EST rszf0FN0 No.56528 Reply
>>56527
rivate_spaceflight_companies" rel="nofollow noopener" target="_blank">https://en.wikipedia.org/wiki/Categoryrivate_spaceflight_companies
Also on that list you won't see Hawking's Breakthrough Starshot project.
Musk's SpaceX and Bezo's BlueOrigin get all the press because everyone likes the idea of billionaires having a pissing match in space, but private space industry is growing very rapidly and many of the 'visionary' founders are doing it expressly because of their understanding of humanity's predicament being stuck on earth.
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Arthur Eddington - Wed, 19 Oct 2016 12:06:23 EST 3t/weoS/ No.56543 Reply
>>56527

NASA's new orbital craft, Orion, is supposed to be capable of manned Lunar missions. Shit's really happening now that the tech is moving beyond the bootstrap suicide missions of the 60/70ies, we just don't hear much of it because the public is so disinterested.

The West ain't gonna let China's space ambitions go uncontested though, so expect more ambitious state-level missions in the future.
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Arno Penzias - Sat, 22 Oct 2016 17:05:33 EST KgKlYmGv No.56548 Reply
You know, OP, you say we have all the resources here on Earth, yet still there's a lot of people living a life of distress due to lack of things and violence. You say we could fix it all, only if everybody started being logical and humane.
But therein lies the problem - it's just that difficult to change humans on that level. So difficult in fact, that it will probably be easier to build a spaceship, living pods and all that's necessary and send it all to another planet with like-minded people that are focused on one goal - making it work there.

In the sense of the mission, the monetary cost is completely irrelevant. 500 years from now nobody will give a shit about how much it cost. Even if there are failures and people will die, it only makes sense for us to keep reaching out there. Once any life arises, it wants to reach out as far as it can.

I don't think mankind really is ready to live in space, until we actually do it and get ready doing it.

balck on black crime part2

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- Thu, 13 Oct 2016 22:29:28 EST XnHvuJOm No.56514
File: 1476412168960.jpg -(1814301B / 1.73MB, 1650x1275) Thumbnail displayed, click image for full size. balck on black crime part2
do you think it would ever be possible for 2 black holes to meet? they say they are growing.. which makes it highly probably they will have a meeting one day.

i don't think anything special would happen other than they merge basically. but i had been thinking because of what they eat, what if one day a black hole has consumed to much...

like a pressure bomb, eventually it'll all be to much. what do you think
5 posts omitted. Click View Thread to read.
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Johannes Kepler - Tue, 18 Oct 2016 20:38:53 EST Kz5Q207u No.56536 Reply
>>56514
You realize we confirmed gravitational waves when LIGO detected the waves caused by two black holes coming together and eventually combining, right?
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George Airy - Tue, 18 Oct 2016 22:05:52 EST y/fkgY/C No.56537 Reply
>>56536
I posted a thread about that when it happened. This board is so fucking slow, it's still there >>56038
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Henrietta Levitt - Wed, 19 Oct 2016 00:22:46 EST rszf0FN0 No.56538 Reply
>>56534
But that presumes there is an unlimited amount of radiation in the interstellar medium. By the time black holes are evaporating en masse, all matter will already have fallen into black holes, so there's no way it could replenish itself with ambient radiation.

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