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SpaceX by Gerard Kuiper - Mon, 21 Dec 2015 21:08:08 EST ID:UJHLFL7d No.55894 Ignore Report Reply Quick Reply
File: 1450750088931.png -(168254B / 164.31KB, 600x488) Thumbnail displayed, click image for full size. 168254
WE FUCKING DID IT
66 posts and 19 images omitted. Click Reply to view.
>>
Nicolaus Copernicus - Fri, 13 Jan 2017 21:04:45 EST ID:s8eqU4E9 No.56757 Ignore Report Quick Reply
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Heads up to ya'll

https://www.youtube.com/watch?v=tTmbSur4fcs
>>
Edmond Halley - Sat, 18 Feb 2017 00:59:16 EST ID:Zekh8fi+ No.56790 Ignore Report Quick Reply
>>55894
Elon Musk is turning to a real life Robert Edwin House.

Lava tunnel societies on Mars is about the dopest shit I've ever heard of though.
>>
Harlow Shapley - Sat, 15 Apr 2017 01:18:51 EST ID:Luev9R23 No.56915 Ignore Report Quick Reply
>>56095
>>
Awe' God !!vVWR8L52 - Tue, 23 May 2017 05:02:51 EST ID:vO6WOJQs No.56945 Ignore Report Quick Reply
I hope they unban you soon my comrade, you were one of the very few that kept me coming back to this forum. You, Bombastus, Void, Fiend and a few others... Thank you for all that you were able to share that I was able to receive and farewell for now.
>>
Awe' God !!vVWR8L52 - Tue, 23 May 2017 05:04:26 EST ID:vO6WOJQs No.56946 Ignore Report Quick Reply
>>55997
To A Wizard


You don't understand galactic scales; Relativity is a bitch thread by Kiyotsugu Hirayama - Thu, 04 May 2017 18:10:19 EST ID:unNII3om No.56931 Ignore Report Reply Quick Reply
File: 1493935819961.png -(221879B / 216.68KB, 521x311) Thumbnail displayed, click image for full size. 221879
So imagine you have two cannons firing their cannon balls away from each other, and their muzzle velocity is the speed of light.

You'd think the relative speed of one cannon ball to the other would be 2x the speed of light, right?

Nope. The equation for relative speed between two objects looks like this:

>v1+2=v1+v2/(1+v1v2/c^2)

Where v1 and v2 are the speeds of the two cannon balls and c is the speed of light.

So as the velocity of the cannon balls approaches the speed of light, their own speed doesn't matter and the limit of light speed is dominant. Relative speed of 2x speed of light is thus impossible.

Or in other words: wat.


You guys got some other relativistic mind-blowers?
5 posts omitted. Click Reply to view.
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Walter Adams - Sat, 13 May 2017 20:13:30 EST ID:unNII3om No.56939 Ignore Report Quick Reply
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>>56938

The Chronicles of the Starship Alexandria. That's the series' name at least.

Though I doubt you can get it outside Norway. Don't think you can get it here either tbh, it's an old 80's-90's thing.
>>
Subramanyan Chandrasekhar - Sun, 14 May 2017 14:27:04 EST ID:7jcVAyVz No.56940 Ignore Report Quick Reply
>>56939
Cool, thanks. I was hoping the internet would have some .pdfs, but it looks like you're right, this guy's stuff is pretty hard to track down. It's a shame the internet doesn't care as much about preserving the literature of quality authors not writing in English than it cares about holding onto a million sources for the same trashy English crap.
>>
James Christy - Fri, 19 May 2017 04:02:03 EST ID:d98JL0hU No.56942 Ignore Report Quick Reply
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>>56932
>>56933

Well, as long as we're on things that'll blow your mind - causal violations are not a problem in relativity. They are in fact expected and on multiple levels. For instance, two people at different reference points, witnessing events unfold in a third, may disagree about their order. There's quite a few other bits of relativity that create causal paradoxes, some of which are plugged up by quantum physics, but it introduces its own:

https://arxiv.org/pdf/1401.0167v1.pdf

There's a limit to the rate of causality, that makes the speed of light, but causality itself is not necessarily inviolable. It just hurts the brain to think of it.

It's also worth noting, that in the cannonball example of OP, the two cannon balls also effectively cease to exist to one another as no information can be passed between them. Worth noting because that's going to be the same fate of every red shifted galaxy in the universe, relative to us, in some hundred billion years (while the handful of blue shifted ones with merge with us). Evidence of the CMB will be gone as well, so for future observers, there will be no evidence of the creation of the universe nor that there were ever any galaxies other than their own.

Which makes you wonder what we're missing already - given that so many galaxies (some estimate 90% of them) have already passed beyond the observable limit.
>>
Anders Angstrom - Fri, 19 May 2017 15:30:33 EST ID:7jcVAyVz No.56943 Ignore Report Quick Reply
>>56942
Awesome paper! Skimming through it now. I certainly am open to the idea that violations of causality are possible; it never made sense to me that the universe would perform some kind of check to keep itself consistent, when it's already so goddamned insane. What then are your thoughts about Hawking's wormhole-radiation-grandfather-suicide claim that a specific causal violation that was loop like would necessarily destroy itself (and maybe everything) with it's own radiation?

>> there will be no evidence of the creation of the universe nor that there were ever any galaxies other than their own.
Sad to think about. Still, hasn't it been said that some very scientifically diligent civilization might be able to deduce all that information about the formation of the universe by studying hyper-velocity stars? (Obviously they would have to take that interpretation on faith, since it could never be confirmed, and would probably always be seen as a theory 'the alleged other galaxies.')

>>Which makes you wonder what we're missing already
Well, if it's the case that spacetime is infinite in extent (which, we have no reason to assume it's not, and the heterogeneity principle suggests it is) then there is a hubble volume somewhere out there in the universe if you travelled long enough that contains every different possible configuration of spacetime for that given volume (in every direction you would care to point into in the sky, as bizarre as it seems, thanks to the unique properties of infinity and probability.)

Which means that, although an infinitesimally small percentage of all the other things that have passed beyond our light horizon -- which would logically be mostly composed of every possible configuration of matter for our physical universe -- there would also be an endless number of Us-es, hubble volumes that, just thanks to statistics, are exactly like our own, with other entities exactly like us, just by chance, some further along, and some further behind. We have missed our own destinies, slipped beyond our light horizon (or, more accurately, probably so far away to begin with their light would never even reach our starting position w…
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Irwin Shapiro - Fri, 19 May 2017 23:22:57 EST ID:yzfSDg8q No.56944 Ignore Report Quick Reply
>>56934
> it's really going to suck when we colonize space

>By the time the two sides met, the far travelers would seem like the ancient primordial civilization to the near colonizers, whereas they would seem to be unfathomably alien and strange to the far travelers. Maybe life just isn't meant to be able to scale to the problems relativity brings about?

I wouldn't worry about it, that's just the natural way of things. Since the far travelers could colonize billions of times the amount of space, they would be the ones spreading across the universe. The close travelers might seem like the primitive culture then, for not being able to grasp the technology. Maybe they could avoid their own destruction long enough to detect the first signals of the far travelers... Can you imagine being in their shoes? Reaching out of their tiny bubble at some point in the distant future and waking up to a universe that's suddenly becoming colonized at the speed of light? They would have no hopes of catching up to the far travelers, unless they develop the technology to travel even faster and contain them somehow. Then they would become the far travelers. Life would get along fine either way, because the universe got colonized.


military equipment by Vesto Slipher - Sat, 15 Apr 2017 19:18:53 EST ID:/DjOl0ut No.56916 Ignore Report Reply Quick Reply
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i understand the weight involved but their are multiple ways to accomplish this

(also i may be missing information on certain things)

with the miscellaneous equipment that is obsolete or ... take an electromagnet to swoop the pieces and clean the atmosphere.. *(my mind was on this)

secondly i think that while it may be applicable to take a large hook and anchor to something to even make some kind of "elevator" - to utilize this to even lift some military equipment - prefabricated buildings... almost anything

a tank is something that came to mind... a submarine would almost work also.. in zero gravity

plus with that.. it comes to understand the problems with entanglement... but also to cheaply move things from station to station on a rope ... much information should be held... but again i don't know who reads these forums

but why not
4 posts omitted. Click Reply to view.
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Irwin Shapiro - Tue, 18 Apr 2017 21:30:03 EST ID:sOANcpac No.56921 Ignore Report Quick Reply
>>56916
Am I too drunk to understand or you made fuck all of a sense?

weight? electromagnet? what?
a tank? submarines in zero gravity?
entanglement?
what?
space elevators?
>>
Fritz Zwicky - Mon, 24 Apr 2017 23:10:01 EST ID:yrPOgYaN No.56923 Ignore Report Quick Reply
>>56917
Actually firearms and cannons would work in space as they already contain all the oxidizer necessary to function. Gunpowder in all forms is a propellant with fuel and oxidizer already in supply. Firearms, cannons, turrets etc are all pressure sealed during firing which means there wouldn't be air in them anyways here on Earth.
>>
Alan Guth - Tue, 25 Apr 2017 01:10:37 EST ID:M/g1akbS No.56924 Ignore Report Quick Reply
what the actual hell am I reading in this thread?
>>
Emelianegro !2iyFNTAIpU - Sat, 29 Apr 2017 13:17:59 EST ID:sm4m2KiS No.56929 Ignore Report Quick Reply
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>>56916
>>
Subramanyan Chandrasekhar - Wed, 17 May 2017 22:54:59 EST ID:ho0i+8BY No.56941 Ignore Report Quick Reply
>>56916

Awesome. 5* post. Lost it at

>rope


EM DRIVVVVVVVVVVE by Joseph-Louis Lagrange - Sun, 20 Nov 2016 17:41:15 EST ID:rszf0FN0 No.56665 Ignore Report Reply Quick Reply
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HOLY SHIIIIIIIIIIIIIIIIIII

So apparently after decades of people trying to debunk it and call it pseudoscience, NASA has confirmed the Shawyer EM Drive actually works, producing thrust via microwaves using no propellant, apparently violating the principle of equal and opposite reaction:
http://www.sciencealert.com/it-s-official-nasa-s-peer-reviewed-em-drive-paper-has-finally-been-published

The authors suggest that perhaps the long-dead pilot-wave/Bohmian interpretation of Quantum Mechanics is now a contender again thanks to this new evidence. The microwaves 'push off' of the quantum vacuum, preserving Newton. But if pilot-wave is the true QM, that means not only that alternate realities exist, but that we see them as real effects in our world! (i.e. in the generation of interference patterns in the double-slit experiment. But surely this is but the most minor influence this generates, and probably only the easiest to notice, since in Bohmian mechanics the wave function that governs any given particle system spans the entire universe.)

NASA's totally unoptimized EM drive could get us to Mars in a tithe of the time of even Musk's proposal, with a ship a fraction of the mass ('cause no propellant.) It's bottle popping time /sagan/!
62 posts and 13 images omitted. Click Reply to view.
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Edmond Halley - Sat, 14 Jan 2017 04:56:45 EST ID:dz7Zv84F No.56758 Ignore Report Quick Reply
>>56756
No, that would be the Xi'an team lead by Juan Yang who actually conducted experiments and published their research. And no, Chen Yue's team has not successfully tested the EM drive in space. Right now his only verifiable success is getting a couple of patents approved (which isn't a very radical development, as cold fusion was patented both in the US and Europe). There's also a Chinese state media press release about building a test device that could in the future be tested in space. Let's talk more about how successful or not the tests were if and when the results of the alleged experiment are published.

Feel free to read the press release yourself. There's been a lot of dodgy science journalism and wild claims in the blogosphere about this lately.
https://translate.google.com/translate?js=n&sl=cn&tl=en&u=http://digitalpaper.stdaily.com/http_www.kjrb.com/kjrb/html/2016-12/11/content_357004.htm

And of course every nation would put it on their satellites if it works - this shit would revolutionize space propulsion, provide free energy to Mankind, and allow us to conquer the stars. But all extraordinary claims require extraordinary evidence. Right now the "best" evidence for the EM drive is shit like this >>56712
Just look at that graph and laugh.
>>
Heinrich Olbers - Wed, 01 Feb 2017 12:14:50 EST ID:7Ip/yKza No.56775 Ignore Report Quick Reply
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>>56719
>Don't you think if that worked someone would have made one by now? Are you a fucking troll?
Oh but they did. Also there isn't a giant sail in front of the fan, which kind of helps.
>>
Kip Thorne - Thu, 02 Feb 2017 03:47:10 EST ID:10QI3ruX No.56777 Ignore Report Quick Reply
>>56758
Damn, all I wanted was unlimited energy and mankind to conquer the universe. This whole thing sounded so star trek at first, but now all my hopes are getting fucking dashed. I just wanted to travel the universe, is that so bad?
>>
Henry Russell - Tue, 28 Feb 2017 15:32:15 EST ID:3rYafGRG No.56844 Ignore Report Quick Reply
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Sounds pretty abstract.
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Henrietta Levitt - Sat, 13 May 2017 15:28:22 EST ID:8y/A2lll No.56937 Ignore Report Quick Reply
so what you are telling me is humans are going to travel the stars powered by

>implying

to seed their memes across the galaxy?


thowing up in your helmet by Johann Encke - Thu, 02 Mar 2017 18:37:45 EST ID:yfFUwunc No.56847 Ignore Report Reply Quick Reply
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Anyone here trying to become an astronaut? I've always wondered what working in space would be like and how bright the stars would shine. Anyone else/
3 posts and 1 images omitted. Click Reply to view.
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William Hartmann - Wed, 15 Mar 2017 00:10:15 EST ID:OXINl/7g No.56864 Ignore Report Quick Reply
These days, to be an astronaut, you have to be a fucking fighter pilot with a PhD in astrophysics or something. The reqs are insane.
>>
Chushiro Hayashi - Tue, 28 Mar 2017 22:30:48 EST ID:rYS5OuxM No.56894 Ignore Report Quick Reply
yea bro im taking ASTRO101 and 102 at community college this summer, should get my astronaut license by october, should be p. cool
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Anders Angstrom - Fri, 31 Mar 2017 02:29:16 EST ID:UUK/Eqa/ No.56898 Ignore Report Quick Reply
>>56894
fuck all that shit ive been watching vids, i got this shit bro hold my beer.
>>
Antony Hewish - Thu, 20 Apr 2017 15:05:50 EST ID:yfFUwunc No.56922 Ignore Report Quick Reply
>>56894 YAAAAAAAAAAAAAAAAAAAAAAAAAAAAY good job and don't die
>>
Giuseppe Piazzi - Wed, 10 May 2017 05:47:05 EST ID:ckzzwmzc No.56935 Ignore Report Quick Reply
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>>56848
>not getting life extending cybernetics that will be real in our time to get a ride to space later.

I think realisticly a lot fo people are going to die soon so survive that and any one left will be go for space, it will be needed.. it's really not that hard you just can't ever fuck up once.


Cassini by Edward Barnard - Wed, 26 Apr 2017 09:23:19 EST ID:rmFM08wB No.56925 Ignore Report Reply Quick Reply
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No Cassini thread? Think we'll find anything we weren't expecting in dem rings?
>>
Maximilian Wolf - Thu, 27 Apr 2017 22:08:11 EST ID:7jcVAyVz No.56926 Ignore Report Quick Reply
>>No Cassini thread?
This board is basically dead at this point, unfortunately. But to answer your question; no, I think they will mostly find rocks, as predicted.
>>
Isaac Newton - Fri, 28 Apr 2017 15:32:16 EST ID:YOYWOEiM No.56927 Ignore Report Quick Reply
>>56926
you are probably right. they know that the rings are 99% ice and the other they dont know what it is
>>
Tadashi Nakajima - Fri, 28 Apr 2017 23:35:28 EST ID:yzfSDg8q No.56928 Ignore Report Quick Reply
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>>56926
What if it's diamonds?
>>
Fred Whipple - Sat, 29 Apr 2017 14:23:19 EST ID:7jcVAyVz No.56930 Ignore Report Quick Reply
>>56928
No but there is that exoplanet made entirely out of diamonds we found. I bet that guy would get pretty jazzed about that.


Fermi Paradox... why? by Henrietta Levitt - Thu, 22 May 2014 00:54:34 EST ID:ILYTISHs No.53812 Ignore Report Reply Quick Reply
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Another thread made me start thinking about this. The Fermi Paradox states (thanks, Wikipedia):

>The Sun is a young star. There are billions of stars in the galaxy that are billions of years older;
>Some of these stars probably have Earth-like planets which, if the Earth is typical, may develop intelligent life;
>Presumably, some of these civilizations will develop interstellar travel, a technology Earth is investigating even now, such as that used in the proposed 100 Year Starship;
>At any practical pace of interstellar travel, the galaxy can be completely colonized in a few tens of millions of years.

If that's the case, why haven't we been colonized already, or at least seen evidence of intelligent life somewhere in our galaxy?

My take: either A) Life takes a long time to develop, and somehow, improbably, we're the first planet to develop an intelligent civilization in our galaxy, or at least one of the first. We don't see anyone else because there isn't anyone else to see... yet, or we're all still too far apart.

Or b) Given the size and composition constraints of a planet able to foster and sustain life (as far as we know, "habitable zone," big enough to have an atmosphere, small enough to still be rocky, etc.) and continue long enough for said life to begin to explore the galaxy, the home planet simply runs out of resources before meaningful headway can be made. I think this is more of a slow-death kind of thing where maybe we get to do some exploration within the solar system and maybe a bit beyond for a while, but overpopulation, war, disease, famine, and whatever else causes us to realign our priorities from space exploration to merely sustaining life on our own planet. A civilization that had the foresight to know something like that was happening could theoretically, if they had the goal of galactic expansion from the start, avoid this situation, but the problem is that NO civilization has that kind of 10,000 year plan from the get-go, and they all sputter out right before they could have pulled it off. There's not a textbook on "how to succeed as a species" that gets handed out to a life form when it develops self-awareness,…
Comment too long. Click here to view the full text.
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Alan Guth - Fri, 31 Mar 2017 21:03:04 EST ID:OXINl/7g No.56899 Ignore Report Quick Reply
>>56897
It seems like it would take an awful lot of bioluminescence to produce enough UV light that it would be detectable from that kind of distance. Granted, our only experience is our own planet, but we tend to see that stuff way, way down in the ocean, and not exactly in massive numbers in one place. The surface usually looks pretty barren.

But yeah, that's a really cool idea.
>>
Walter Baade - Fri, 31 Mar 2017 22:11:50 EST ID:7jcVAyVz No.56901 Ignore Report Quick Reply
>>56899
http://news.nationalgeographic.com/2016/08/planet-proxima-centauri-life-glowing-corals-radiation-space-science/
Turns out it was Proxima B, and the specific idea was that bioluminescening on a major scale would be one possible coping strategy for the extreme radiation there. On top of that, Proxima is literally the closest star, so if we could detect it anywhere, it would be there.
>>
Alan Guth - Sat, 01 Apr 2017 08:42:25 EST ID:OXINl/7g No.56902 Ignore Report Quick Reply
>>56901
Goddamn, science is fucking cool.
>>
Paul Goldsmith - Fri, 14 Apr 2017 04:10:12 EST ID:0hw+A2Pn No.56913 Ignore Report Quick Reply
>>53812
I think they are already here and undercover dude. Unless we are the ONLY life, it is the only conclusion with any real logic besides maybe there is no possible way to travel fast enough to get anywhere
>>
Walter Baade - Fri, 14 Apr 2017 16:59:27 EST ID:7jcVAyVz No.56914 Ignore Report Quick Reply
>>56913
>>besides maybe there is no possible way to travel fast enough to get anywhere
Over the timescales we're talking about, 50% of the speed of light is more than sufficient to colonize the galaxy, and there's no reason to believe such a speed isn't achievable.


Accelerating Expansion of the Universe by Johann Encke - Thu, 23 Mar 2017 18:41:02 EST ID:pYbb5iMl No.56876 Ignore Report Reply Quick Reply
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So if new space is created every now and then at greater speed and making them galaxies recede and shift to the reddest part of the spectrum, how much time until we're converted into a gaseous fading cosmic entity? How do we even perceive space? How would we perceive space expanding when it eventually gets fast enough to notice?
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Mike Brown - Mon, 03 Apr 2017 15:06:53 EST ID:7jcVAyVz No.56904 Ignore Report Quick Reply
>>56903
Everything about the rip scenario is dependent on the nature of dark matter/energy. Specifically the ratio between its density and pressure, which may be positive or negative, or even zero (in the case where it turns out the dark substances aren't real.) The only real way we can differentiate between these cases is by getting actual observational evidence on this characteristic of the dark substances.
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Ejnar Hertzprung - Wed, 05 Apr 2017 14:49:04 EST ID:f/Tl+D5o No.56905 Ignore Report Quick Reply
I think there are beams of light and holes in the wall from the centralized spectral creation. We are one of the beamed holes, because we expanded from a such tiny space compression.
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Paul Goldsmith - Wed, 05 Apr 2017 16:12:44 EST ID:7jcVAyVz No.56906 Ignore Report Quick Reply
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>>56905
>>
Ejnar Hertzprung - Wed, 12 Apr 2017 00:12:46 EST ID:TSBuLBRU No.56910 Ignore Report Quick Reply
>>56903

how can anything ever overcome the force of gravity? isn't its reach limitless?
>>
Daniel Kirkwood - Wed, 12 Apr 2017 16:18:05 EST ID:7jcVAyVz No.56911 Ignore Report Quick Reply
>>56910
But it's power isn't limitless. Consider that the reach of the power of the sun's gravity is much stronger than the earth's, but because you are much closer to the earth, the sun's gravity doesn't pull you into it (well, it does in that it keeps the earth in orbit, but you see my point, that just because a force extends infinitely doesn't mean it isn't weaker at any given place than some other force.)


Contact by Georges-Henri Lemaitre - Tue, 07 Mar 2017 10:24:21 EST ID:d9ijPul/ No.56851 Ignore Report Reply Quick Reply
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Say we could float around and travel in space like a super saiyan god: Could we create scouters which could contact people with the same scouter intergallactically?
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Isaac Newton - Sun, 19 Mar 2017 20:59:18 EST ID:tNU6hJcf No.56869 Ignore Report Quick Reply
na but u cud use Instant Transmission to teleport and chat then teleport back
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Edwin Salpeter - Mon, 20 Mar 2017 03:31:27 EST ID:RH1VsRBv No.56870 Ignore Report Quick Reply
>>56865
>The Tao is like a well:
>Used but never used up.

wells run dry all the time
>>
Carl Seyfert - Wed, 22 Mar 2017 06:55:46 EST ID:d9ijPul/ No.56871 Ignore Report Quick Reply
>>56870
yeah the bad ones without a large influx to source from.
>>
Johann Encke - Sun, 09 Apr 2017 04:20:44 EST ID:eKHOYimM No.56908 Ignore Report Quick Reply
>>56870
If it does up it wasn't a well, it was a just hollow.
>>
John Bahcall - Sun, 09 Apr 2017 16:22:13 EST ID:7jcVAyVz No.56909 Ignore Report Quick Reply
>>56908
You don't understand how wells work do you?


Dark matter matters by Clyde Tombaugh - Wed, 09 Nov 2016 03:09:08 EST ID:zHoQtF+M No.56645 Ignore Report Reply Quick Reply
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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.
21 posts and 5 images omitted. Click Reply to view.
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Daniel Kirkwood - Tue, 14 Feb 2017 03:27:41 EST ID:M/g1akbS No.56785 Ignore Report Quick Reply
>>56783
>Yo, I agree with most of what you've said man but...
Yeah, I was mad in that last part, excuse the flippancy. You raise a valid point about the snapshots-in-time. The only caveat is that we can observe [usually] the same type of effect in several locations in the sky. This can give us a good correlation to the observed effect being distributed evenly in the universe.


It is my sincere wish, however, that we stop poking logic holes in each others' theories [see >>56645 and >>56748 ], and start referencing actual science articles to back up assertions. OP did a good job supplying articles to chew on, followed by good counterpoints by others. Lets get more of that.
>>
Johann Bode - Fri, 17 Feb 2017 23:29:59 EST ID:yzfSDg8q No.56789 Ignore Report Quick Reply
>>56785
Well I wouldn't call it a snapshot in time, but rather a snapshot in perception. Our view of the universe is always changing, so the picture we have right now is only a snapshot, regardless of how much time it represents. You can say the current laws of physics are immutable and timeless, but these laws have only been accepted as a general concept of the universe for a couple hundred years. Previous theories of the universe such as Platonic Idealism were also based on observation, and were of course supposed to be immutable. They lasted for thousands of years.
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Bruon Rossi - Mon, 27 Feb 2017 13:16:01 EST ID:FoZr+PSB No.56843 Ignore Report Quick Reply
http://cosmos.nautil.us/short/144/the-physicist-who-denies-that-dark-matter-exists
>Dark matter is our generation's ether
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George Herbig - Tue, 28 Feb 2017 21:08:22 EST ID:7jcVAyVz No.56845 Ignore Report Quick 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?
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John Bahcall - Wed, 01 Mar 2017 19:11:28 EST ID:e0oA2mYt No.56846 Ignore Report Quick 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.


Other worlds by William Herschel - Tue, 08 Nov 2016 04:19:55 EST ID:FFHdMrF/ No.56642 Ignore Report Reply Quick Reply
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Do you think we will be capable to leave our solar system one day? Or that getting even to the closest star is impossible.
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James Elliott - Tue, 29 Nov 2016 18:44:49 EST ID:2iiuuOyi No.56694 Ignore Report Quick Reply
I think we will, we just don't understand space well enough or have the proper measurement devices to do it yet.

My train of thought goes like this: It wasn't until Newton we were able to invent the sextant, which in turned allowed us to traverse the globe. It wasn't until Einstein that we were able to move around in outer space.

I think next level physics and measurements will allow us to move through space more efficiently. Maybe a holographic universe, gravitational astronomy, or mastery of quantum mechanics will lead to avenues that allow mundane interstellar travel
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Edwin Hubble - Fri, 02 Dec 2016 17:07:44 EST ID:OXINl/7g No.56701 Ignore Report Quick Reply
>>56642
Impossible, no. Time-consuming, definitely. Right now, the fastest speed we think is possible is the Speed of Light, and it would still take ~3 years to get "next door" at that rate. We're not really capable of propelling any considerable mass to the Speed of Light, and we're definitely not capable of stopping if we did. But with technology we currently have, we could get to Proxima Centauri in a few hundred years (maybe not live humans), and that time will only get shorter and shorter. It's just a mater of when we think the travel time is short enough to pay off.
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Arno Penzias - Fri, 16 Dec 2016 15:14:16 EST ID:nRjWggLk No.56725 Ignore Report Quick Reply
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I wanna go to space, get me some space pussy.
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Johann Bode - Wed, 21 Dec 2016 19:38:59 EST ID:SD/dK0pb No.56732 Ignore Report Quick Reply
>>56694

europeans were sailing to asia in the late 1400's.
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Pierre-Simon Laplace - Fri, 24 Feb 2017 23:19:23 EST ID:r2zIu0Bs No.56842 Ignore Report Quick Reply
YA


Europa Mission by Ejnar Hertzprung - Thu, 18 Aug 2016 23:04:09 EST ID:Y3T9nNnZ No.56318 Ignore Report Reply Quick Reply
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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.
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James Christy - Wed, 26 Oct 2016 20:20:15 EST ID:10QI3ruX No.56559 Ignore Report Quick Reply
>>56558
You've gotta think about the big picture here. Life in space, sustainable places for people to live, things that could be mined (cause yes humans will eventually sap away from everywhere they vist and live) its like the cycle of industrialization starting up again. But only this time, its going to be on other planets. Mars colonization is the first step to this, discoveries in space will prod on intrest, and in the end, we'll end up with a very much diffrent existance as human beings. Mankind can spread out to the stars, and make colony after colony, thats how I envision it.
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William Lassell - Thu, 03 Nov 2016 16:15:00 EST ID:OXINl/7g No.56616 Ignore Report Quick Reply
>>56558
There's probably no direct incentive outside of advertising (Company X went to Europa, so buy our shit because we're awesome like that). But these are all kinds of scientific benefits that might also be good for a private company down the road: pharmaceuticals, materials science, genetic engineering, etc. Plus just having the infrastructure in place in capitalize on new sources of ET-related income if/when they figure one out would allow you to get in on the ground floor, so-to-speak.
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Astrobiology Student - Wed, 23 Nov 2016 16:14:22 EST ID:UuJsarOA No.56671 Ignore Report Quick 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!
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Fred Whipple - Fri, 10 Feb 2017 04:24:21 EST ID:tNU6hJcf No.56781 Ignore Report Quick Reply
>>56671

please, share some of the key details
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George Gamow - Thu, 16 Feb 2017 22:54:10 EST ID:U3oyeBRN No.56788 Ignore Report Quick Reply
>>56318

I'm waiting for Triton Sample Return.


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