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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
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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?
20 posts and 2 images omitted. Click Reply to view.
>>
William Hartmann - Mon, 11 Sep 2017 13:15:57 EST ID:kRyBQtrI No.57015 Ignore Report Quick Reply
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>>56993
>WikiHow
But you're helpful otherwise.
>>
Fred Hoyle - Sun, 15 Oct 2017 20:38:36 EST ID:lQ9q0NgK No.57061 Ignore Report Quick Reply
>>56942
>causal violations are not a problem in relativity. They are in fact expected and on multiple levels
I would disagree with this sentiment. Although violations of causality certainly may be possible, I would argue that the general (excuse the pun) theories of S.R. and G.R. rely heavily on the notion that causality is inviolable. In example of separate observers witnessing events, you are confusing causality with simultaneity. This is only possible for events that are causally separated (spacelike). If events can be perceived as simultaneous in some reference frame S, then they must be causally separated if there is nonzero distance between them (in S). Special relativity and causality allows you to boost to some frame S' with nonzero velocity relative to S such that the events occur out of order, however no matter how fast you go in S', the events will never occur in each other's light cone without exceeding the speed of light, and therefore cannot be causally related. tl;dr: violating simultaneity is not violating causality.

>There's a limit to the rate of causality, that makes the speed of light, but causality itself is not necessarily inviolable
Central to relativity is the notion that the speed of light is the same in any reference frame and cannot be exceeded. As you alluded to here, causality is defined by the speed of light (if event b occurs before light from event a could have reached it, then a cannot have caused b because the information that a has occurred will reach b after b happens). Therefore in order to violate causality, you must exceed the speed of light, which is forbidden in relativity.
With that said, that paper is certainly an interesting read, but it is investigating possible mechanisms of causal violation that would modify or extend the existing theories of relativity. It is well known that quantum mechanics and general relativity don't get along, and thus a theory of "quantum gravity" will have to violate some well established principals, but this is just the nature of science. I'm trying not to argue that causal violations are impossible, just that the notion that causal violations are expected by conventional relativity is …
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Jocelyn Bell - Thu, 02 Nov 2017 07:39:24 EST ID:eygzYfFg No.57072 Ignore Report Quick Reply
>>56933
Wromholes don't mess with time because you bend space. Time still flows through the wormhole.
>>
George Hale - Sat, 04 Nov 2017 17:29:49 EST ID:unNII3om No.57075 Ignore Report Quick Reply
>>57072

Um no? It's known as the one most likely way of traveling through time dude. Remember time and space are two sides of the some coin. You bend one you bend the other.
>>
Charles Bolton - Sun, 03 Dec 2017 16:31:39 EST ID:+kYrHA6N No.57114 Ignore Report Quick Reply
>>57072

then how did Tasha Yar have a daughter?


Ayy-lmao! A steroid! by Christiaan Huygens - Fri, 27 Oct 2017 23:01:24 EST ID:RH1VsRBv No.57067 Ignore Report Reply Quick Reply
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https://www.cnet.com/news/interstellar-asteroid-comet-a-2017-u1-pan-starrs-nasa-earth/

>All the asteroids and comets astronomers have ever spotted in our celestial neighborhood appear to come from somewhere else in the solar system and orbit the sun, just like Earth.

That is, until the University of Hawaii's Pan-STARRS 1 telescope last week discovered what appears to be the first ever seen "interstellar object" -- an asteroid (or maybe a comet) that escaped from the gravitational grasp of another star and fell through the roof of our solar system.

That makes the object currently designated A/2017 U1 an alien of sorts around our corner of the cosmos.

The foreign space-something is less than a quarter-mile (400 meters) across, but is moving super fast at 15.8 miles (25.5 kilometers) per second. That's over three times faster than Asteroid 2012 TC4, the rock that gave Earth a close shave earlier this month.

"This is the most extreme orbit I have ever seen," said Davide Farnocchia, at NASA's Center for Near-Earth Object Studies (CNEOS). "It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back."
>>
Maximilian Wolf - Sun, 29 Oct 2017 03:25:09 EST ID:iHcy51j9 No.57068 Ignore Report Quick Reply
A little eerie.
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Nicolaus Copernicus - Fri, 10 Nov 2017 02:51:08 EST ID:XdfxkLaX No.57085 Ignore Report Quick Reply
Imagine the shit that goes faster than that tho.


Hey Nerds by Antony Hewish - Sun, 23 Jul 2017 18:26:46 EST ID:Fbpr3rrr No.56982 Ignore Report Reply Quick Reply
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I was wondering why you guys post here? Aren't these boards ungodly slow? Wouldn't it be easier for you to just go to an actual forum for space discussion? Why wait so long for a reply from some drug addict about stars or whatever when you can probably get better information more quickly from somewhere else?

Not judging, just genuinely curious
11 posts and 1 images omitted. Click Reply to view.
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hokusai - Sat, 19 Aug 2017 11:26:42 EST ID:LIO8YU+/ No.57003 Ignore Report Quick Reply
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havent read the thread but i dont thing faster than light travel is possible the way it will be done is not by moving objects but consciousness around space outside time thats why i post here and not in a science forum
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Margaret Burbidge - Sun, 20 Aug 2017 05:14:34 EST ID:PovkMdyu No.57005 Ignore Report Quick Reply
Is there really any faster forum than a chance? I mean besides ones filled with terms like "social media"
>>
Kip Thorne - Thu, 12 Oct 2017 14:09:23 EST ID:KX/DxO6v No.57048 Ignore Report Quick Reply
>>56999

speed exists in relation to predetermined points on a coordinate system
>>
James Elliott - Thu, 12 Oct 2017 16:50:14 EST ID:unNII3om No.57050 Ignore Report Quick Reply
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>>57048

Space has no inherent coordinate system dude. This is like one of THE realizations of relativism.
>>
Kip Thorne - Thu, 12 Oct 2017 19:57:11 EST ID:KX/DxO6v No.57052 Ignore Report Quick Reply
>>57050

yep, very good. now let's break down relativism: that which is relative [to a given frame of reference]; i.e. you make up your own system as an observer, which will be different from every other observer's system. an object in motion in relation to another object in motion can only have a determinate speed (if we are serious about this conversation we should start using the term velocity, actually) within a predetermined system.


SpaceEngine/Universe Sandbox Thread! by Cosmobud - Mon, 18 Sep 2017 22:41:08 EST ID:1NT/Ijtb No.57022 Ignore Report Reply Quick Reply
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Why isn't there one? Post your awesome finds, explosions, super novae, whatever! OP image will be from Universe Sandbox, I'll post another from Space Engine.
>>
Cosmobud - Mon, 18 Sep 2017 22:52:10 EST ID:1NT/Ijtb No.57023 Ignore Report Quick Reply
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>>57022
>>
Walter Adams - Fri, 22 Sep 2017 19:44:24 EST ID:3hL9HQte No.57026 Ignore Report Quick Reply
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>>57022
>>57023
>>57024
tfw no space engine VR support yet
>>
Harlow Shapley - Sat, 23 Sep 2017 02:26:00 EST ID:ur3W8pPa No.57027 Ignore Report Quick Reply
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Not sure where this was.


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?
5 posts and 2 images omitted. Click Reply to view.
>>
Alan Guth - Thu, 13 Jul 2017 18:48:31 EST ID:unNII3om No.56978 Ignore Report Quick Reply
>>56977

Aw man, what a downer.
>>
George Herbig - Fri, 14 Jul 2017 03:51:43 EST ID:nRjWggLk No.56979 Ignore Report Quick Reply
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>>56977
>>
Paul Goldsmith - Wed, 19 Jul 2017 14:04:24 EST ID:yxm0fECC No.56981 Ignore Report Quick Reply
>>56977
shouldn't a bunch of scientists be able to at least count properly?
>>
John Wheeler - Thu, 14 Sep 2017 23:31:42 EST ID:CZNpyEE2 No.57019 Ignore Report Quick Reply
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Goodnight sweet prince
>>
Charles Messier - Mon, 18 Sep 2017 15:15:40 EST ID:HLehYNUW No.57021 Ignore Report Quick Reply
>>56977
Fraisier Cain is that you?


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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Subramanyan Chandrasekhar - Sat, 10 Jun 2017 16:28:00 EST ID:unNII3om No.56952 Ignore Report Quick Reply
>>56950

Just an interesting consequence of relativity: As you approach the speed of light, time slows down. While the trip might take decades or centuries from our perspective, it can take significantly less from the perspective of the travelers. With an efficient enough vessel, traveling to Alpha Centauri can theoretically be done without generation-ships.
>>
William Lassell - Fri, 23 Jun 2017 17:10:24 EST ID:iClpwVzv No.56958 Ignore Report Quick Reply
>>56952
Even without time dilation, Alpha Centauri isn't that far.
If we could accelerate at 1g halfway, then decelerate at 1g the other half, it would only take 6 years without time dilation (3.5 years with dilation).
That kind of acceleration is a tall order though.
At only one tenth of a g, it's still only about 13.6 years to an outside observer.
Google "relativistic star ship calculator". I like the one from convertalot.com
>>
Stephen Hawking - Fri, 25 Aug 2017 23:54:14 EST ID:p1UqQx6T No.57012 Ignore Report Quick Reply
>>56644
The budget is what makes it impossible. As such, humans don't deserve to leave. Money and the idea of it holds us back more than people will ever realize. If man would just stop being selfish and/or trying to control others, we would be so far ahead. Those that want to waste away would be allowed to and those that want to do something great would be able to, because without money, the only thing holding you back would be yourself. In this life, it's both other people and money.
>>
Clyde Tombaugh - Fri, 01 Sep 2017 17:36:46 EST ID:unNII3om No.57014 Ignore Report Quick Reply
>>57012

Only that doing anything of the high-tech sort demands a huge cooperation between people. The guys who build the constituent parts of the rockets, how do they eat without bartering something for their work? How do the scientists eat without bartering something for their work?
>>
Verty - Wed, 13 Sep 2017 01:08:39 EST ID:VRvuffr/ No.57016 Ignore Report Quick Reply
We won't be able to go anywhere important until we figure out how to fold space-time, which some aliens already have as I saw.


Perseid meteor shower! by Johann Encke - Wed, 31 Jul 2013 11:29:34 EST ID:evrPe8Vs No.51233 Ignore Report Reply Quick Reply
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AWWWW YEAAAH.
Anyone else gonna observe this beautiful event?


Incase you haven't heard from AUG 12th to the 13th between 10:30PM and 4:30 AM, The sky's gonna light up with massive fireballs brighter than Jupiter.
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Wilhelm Beer - Sat, 27 Aug 2016 04:13:56 EST ID:Y/YEbfJF No.56331 Ignore Report Quick Reply
I actually got to see it on the night of the 12th. I was on the east coast in outer banks on vacation. Was smoking js and sipping coladas with a pretty girl i just met. Walkin back to my house we saw one right above our house direction wise. Which was freaking awesome cause it looked like a ufo or something. And you can see lots of stars out there on the coast. We saw about 5 in an hour but we werent even looking. They were super low too
>>
Edwin Hubble - Sat, 01 Oct 2016 12:47:50 EST ID:r8ZHfF3E No.56504 Ignore Report Quick Reply
It was considerably longer last year and it was visible in the city.
We must have been in the outskirts of the geminid
>>
Gerard Kuiper - Wed, 09 Aug 2017 18:42:14 EST ID:/VSfubHK No.56997 Ignore Report Quick Reply
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Anyone going to observe this year's Perseid meteor shower?
>>
Wilhelm Beer - Tue, 15 Aug 2017 00:15:44 EST ID:uuw9w7i5 No.57000 Ignore Report Quick Reply
I did not know this was annual

you failed me Sagan
>>
William Lassell - Sat, 19 Aug 2017 22:02:46 EST ID:dG4sHLwu No.57004 Ignore Report Quick Reply
I caught sight of seven or so. Too bad it was too cloudy most of the time. Really want to go out of the city for next year.


Books! by William Lassell - Fri, 28 Jul 2017 19:52:00 EST ID:CtWYD6pG No.56988 Ignore Report Reply Quick Reply
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Can you recommend me soke books on the universe in general. Like books on astrophysics , black holes or planets. Thank you.
>>
Bernhard Schmidt - Wed, 16 Aug 2017 23:44:30 EST ID:nRjWggLk No.57001 Ignore Report Quick Reply
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>>56988


The Night Sky. by George Herbig - Thu, 06 Jul 2017 19:26:48 EST ID:5rTlMpAv No.56975 Ignore Report Reply Quick Reply
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It was late august and the skies were perfect out in the cornfields of Nebraska,
It was the darkest I've ever seen, I couldn't see my hand in front of me, let alone the stalks.

After about half an hour of stumbling through the field trying to find my spot, (a clearing that my friend used to grow weed) I finally stumbled upon a small trail that led to the clearing.

In the clearing there was a trailer, a lawnchair, a cooler and a telescope. I turned on my lantern and went into the trailer. There were stalks of weed hanging on clotheslines as well as a few pills scattered on a table with a note that said "help yourself", with a winky face alongside a condom.

I thought it was a prank, but I thought I might as well so I took the pills all at once and shaved off a nug branch of uncured weed and smoked it the best I could. Anyway I got out my telescope and used my night-sky app on my phone to find the planets (yeah I know, I'm lazy).

As I was focusing in on Saturn I noticed my vision started to blur a bit. I thought at first the lense was just out of focus but I soon found that something was happening. I continued my search anyway, the best I could until I could no longer keep up.

I decided to just chill on a tarp and watch the stars instead, see If I could make out the ISS and other satellites. I started thinking about how those stars are actually clusters of galaxies that are probably gone, it made me sad but then I felt something.

My dick was hard as a rock., On top of that the stars wouldn't stay still. It was bothering the fuck out of me until it didn't. I started to see my own constellations, they turned into titties and even full on line-porn.
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Joseph Taylor Jr. - Sun, 23 Jul 2017 22:19:45 EST ID:s0XmRX5r No.56983 Ignore Report Quick Reply
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havent heard that one before


oh cool by Pierre-Simon Laplace - Tue, 18 Jul 2017 14:04:36 EST ID:T69KfNA1 No.56980 Ignore Report Reply Quick Reply
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imagine what planet discovering when listening to thids
https://www.youtube.com/watch?v=7vj-3bafIMI


black holes by analnonymphus - Sun, 25 Jun 2017 08:49:44 EST ID:M9cvTU1A No.56960 Ignore Report Reply Quick Reply
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so cern was built and there were quite a few expermiments done there, now i am wondering why we are shooting particles through earth "for different reasons" are we measuring for a difference in gravity? also i read an really awkward article about alot of stars and planets naturally containing black holes (sounds like the cancer lie to me - its natural and in every body in low amounts- and i have cancer and know how i got it - chemically) so whats goind on here? possibly does anyone know the maths to how fast a black hole grows? just asking ...
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analnonymphus - Sun, 25 Jun 2017 13:39:03 EST ID:M9cvTU1A No.56962 Ignore Report Quick Reply
so how man particles smaller than atoms are there around to float threw earth and what is their mass, also what mass must a black hole have to be able to suck up basic elements like iron( or heavier) from the earths core? cant do the math since i have a braintumor! ... just wondering though i didnt make the black hole or the plans behind it!
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Bruon Rossi - Sun, 25 Jun 2017 15:28:04 EST ID:2fBRstom No.56964 Ignore Report Quick Reply
>>56962
Black holes don't suck. They have the same gravitational attraction as anything with the same mass. They just pack that mass in a small enough volume that internal gravity overcomes all the other forces.

As for particles, I don't get what you're asking, man.
>>
analnonymphus - Sun, 25 Jun 2017 17:15:26 EST ID:yhLhjf2W No.56965 Ignore Report Quick Reply
just wondering how a miniature black hole in earths core would start feeding, would it be particles and atomdust from space? would it already initially be molten metals?
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analnonymphus - Sun, 25 Jun 2017 17:17:20 EST ID:yhLhjf2W No.56966 Ignore Report Quick Reply
by particles i mean bosons and fermions
>>
Henry Draper - Thu, 29 Jun 2017 01:38:31 EST ID:kjgELPni No.56968 Ignore Report Quick Reply
>>56966
You're reaching into subject matter that I think you probably need more reference knowledge for to be able to integrate fully. Probably best to just not worry about such things in that case.
But, the idea that there could be microscopic black holes capable of passing through the earth is just from one study by one physicist, as a way to explain something that probably has a much simpler explanation i.e. the LHC doesn't generate micro black holes simply because the LHC isn't capable of generating micro black holes . The accepted explanation concerning black holes in the standard model is that they continually lose mass due to Hawking radiation, and thus eventually evaporate completely, so by most physicists estimation, long lived subatomic scale black holes don't exist.

If there were a black hole in the center of the earth, then the center of the earth would fall into its event horizon, which would subsequently expand. In short order, the entire earth would be within the black hole. Anything that comes into physical contact with the event horizon becomes a part of the black hole, and since the center of the earth is completely pressurized with no vacuous space, it would consume the earth more or less instantaneously from our perspective, from the inside out.

The amount of the mass that subatomic particles, that could pass through such an object that weren't already part of the earth's mass -- like neutrinos burrowing through from the sun, would contribute to the total mass of an earth-consuming black hole would be vanishingly negligible, more or less equivalent to the number of neutrinos that pass through the earth during the time it took the black hole to consume it, (which would again, would on the order of seconds, perhaps minutes) pico grams of substance compared to the earth's 5x10^24 Kgs.


SpaceX by Gerard Kuiper - Mon, 21 Dec 2015 21:08:08 EST ID:UJHLFL7d No.55894 Ignore Report Reply Quick Reply
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WE FUCKING DID IT
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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.
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Awe' God !!vVWR8L52 - Tue, 23 May 2017 05:04:26 EST ID:vO6WOJQs No.56946 Ignore Report Quick Reply
>>55997
To A Wizard
>>
Samsara Siddhartha - Fri, 16 Jun 2017 09:36:59 EST ID:mhvoJT06 No.56954 Ignore Report Quick Reply
>>55894
Hot off the presses! Freely available until July 5th! <spoiler>Unless you http://sci-hub.io/</spoiler>
http://online.liebertpub.com/doi/full/10.1089/space.2017.29009.emu
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Samsara Siddhartha - Fri, 16 Jun 2017 09:38:50 EST ID:mhvoJT06 No.56955 Ignore Report Quick Reply
>>56954
Fail!
also this https://arstechnica.com/science/2017/06/air-force-budget-reveals-how-much-spacex-undercuts-launch-prices/
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Samsara Siddhartha - Mon, 26 Jun 2017 11:16:24 EST ID:VzPcpzRp No.56967 Ignore Report Quick Reply
The winning continues
https://www.theverge.com/2017/6/25/15870934/spacex-second-launch-weekend-rocket-landing-success-falcon-9-landing


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