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CERES, BITCH by Stephen Hawking - Thu, 26 Feb 2015 04:28:40 EST ID:uyuUt0io No.55065 Ignore Report Reply Quick Reply
File: 1424942920059.jpg -(467396B / 456.44KB, 1873x1044) Thumbnail displayed, click image for full size. 467396
LOOK AT THIS FUCKING THING
HOW NEAT
4 posts and 1 images omitted. Click Reply to view.
>>
Galileo Galilei - Tue, 03 Mar 2015 21:49:22 EST ID:XJHlYsmW No.55092 Ignore Report Quick Reply
>>55070

Cryovolcanism isn't new, we've seen it on Enceladus and probably on Europa and Titan, too.
>>
Russel Hulse - Wed, 04 Mar 2015 15:49:05 EST ID:jGLzk50k No.55097 Ignore Report Quick Reply
>>55065
This is pretty fucking neat
Whatever it may be, it looks interesting to the layman like myself

I guess we'll have a better idea on friday (?)
>>
Stephen Hawking - Fri, 06 Mar 2015 14:16:37 EST ID:jGLzk50k No.55108 Ignore Report Quick Reply
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http://www.nasa.gov/press/2015/march/nasa-spacecraft-becomes-first-to-orbit-a-dwarf-planet/index.html#.VPn4fXysWrj

It's in orbit!
I would be lying, if i said i wasn't excited most about the bright spots.
Seems like it's a bit of a wait still, until we get clearer images, though.
It's pretty fucking cool nevertheless

"The most recent images received from the spacecraft, taken on March 1 show
Ceres as a crescent, mostly in shadow because the spacecraft's trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres' dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet."
>>
George Hale - Tue, 17 Mar 2015 19:17:32 EST ID:uyuUt0io No.55142 Ignore Report Quick Reply
>>55070
http://news.sciencemag.org/space/2015/03/scientists-may-have-solved-mystery-dwarf-planet-s-enigmatic-bright-spot?utm_source=facebook&utm_medium=social&utm_campaign=facebook

You seem to be correct, sir!
Looks like it's water vapor outgassing. NEAT
>>
Fred Whipple - Mon, 27 Apr 2015 17:06:39 EST ID:l/7F60uv No.55258 Ignore Report Quick Reply
>>55092
I think you're defining the word "novel" too strictly. I'd consider any form of cryovolcanism to be novel because the evidence itself is relatively new and much of it is based on indirect observation.


Astronomy 101 by Allan Sandage - Tue, 10 Mar 2015 16:45:18 EST ID:ng5PGFH1 No.55120 Ignore Report Reply Quick Reply
File: 1426020318482.jpg -(119531B / 116.73KB, 847x845) Thumbnail displayed, click image for full size. 119531
I need your help, I'm completely clueless.
If Hydrogen has a spectral line of 656nm and it is measured in a distant galaxy at 705nm, how would you find the recessional velocity of the galaxy?
>>
Edmond Halley - Tue, 10 Mar 2015 17:23:02 EST ID:kB08C8qN No.55121 Ignore Report Quick Reply
>>55120
DeltaLamda/Lambda=v/c
>>
Edmond Halley - Wed, 11 Mar 2015 18:13:34 EST ID:rjqBmvyM No.55125 Ignore Report Quick Reply
Wouldn't you need at least one other line? A given spectrum could be translated as well as stretched/compressed, and a single line wouldn't be able to distinguish those, right?
>>
Edwin Salpeter - Sat, 14 Mar 2015 10:41:12 EST ID:kB08C8qN No.55130 Ignore Report Quick Reply
>>55125
Wavelength dependent effects are rare and in the optical almost always destroy the lines. Just treat it all as a velocity, it's the safest bet.


Size And Age Of Universe Suggests The Existence Of Alien Life by Alium Man - Fri, 06 Mar 2015 11:18:40 EST ID:CLP0/vbo No.55104 Ignore Report Reply Quick Reply
File: 1425658720324.jpg -(5752B / 5.62KB, 276x182) Thumbnail displayed, click image for full size. 5752
We are not alone in the universe, just because we have not found life on other planets some people seem to doubt the possibility of alien life. I'm just here to tell you we have not even explored 1% of our galaxy for alien life. It's even probable that there are sentient species as advanced or more advanced than our own i this galaxy based upon the age of it. The main ingredients for life (amino acids) are not that uncommon from what we know. How do we know for sure those are not alien spacecraft we see on occasion in our skies? What's your theory on how advanced alien life is?
>>
Christiaan Huygens - Sat, 07 Mar 2015 18:34:09 EST ID:uyuUt0io No.55113 Ignore Report Quick Reply
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>>55104
there's already a space alien thread on page 0, so i'm not gonna bump, but until we find fossils or microbes or something somewhere that isn't Earth, or until somebody talks to us, it isn't 'probable', it's possible. We've literally got a sample size of 1 to look at right now. Kind of impossible to determine probability based on the one single rock in a galaxy with billions and billions of rocks that sprouted life.
It's fun to think about, and I'm in the camp that believes there's life out there, but we just can't possibly know it based how very, very little we can observe things not on Earth.

Furthermore, 'sentient' life seems like an unbelievably rare occurrence. It's only happened once here. Multicellular life in itself is probably excessively rare if life even exists elsewhere to begin with, animal life even moreso. Rarer still would be a self-aware species. Yet rarer would be self-aware species capable of technological civilization. It's fairly safe to assume quite a few civilizations would end themselves before reaching the stars, and who knows; it might simply be too much time and energy to cross interstellar space for such a species to leave its home planet.

UFOs being filled with little green men is silly, though. Remember all those UFO sightings in the American Southwest during the Cold War? How people thought that they had flying saucers holed up in Area 51, and then a bunch of files were declassified and it turned out the Air Force was testing SR71s and shit out there?
If space aliens have the technology to efficiently get around and build a galactic civilization, then we're like, an ant colony in New York City to them. So advanced compared to us that we could not possibly comprehend them.

I dunno, man. Imagine what people might be like if we manage to maintain a technological civilization for a a thousand, a hundred thousand, one million, five hundred million, even billions of years.

Who knows, though, maybe we're lucky number one. The first civilization to emerge in the galaxy. It's not unfeasible, really. Shit, we might even be the first planet to have life. Or …
Comment too long. Click here to view the full text.


Greased Darkspeed by Shit Hettingstock - Wed, 04 Feb 2015 18:24:41 EST ID:IhokWyRc No.54990 Ignore Report Reply Quick Reply
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Slip the what? Dark the who? MY HEAD ASPLODE
SHUT THE FUCK UP I MADE THE KESSEL RUN IN TWELVE PARSECS SOBSOB SOB
>>
Bernhard Schmidt - Thu, 05 Feb 2015 19:02:24 EST ID:3dhJAQX4 No.54996 Ignore Report Quick Reply
I always wonder what people who make these sort of threads are like in real life. It fascinates me.
>>
Caroline Herschel - Mon, 16 Feb 2015 07:15:19 EST ID:ZZdLgro4 No.55041 Ignore Report Quick Reply
>>54996
>OP
>asperger levels above space


Non-stellar black hole by Alan Guth - Sun, 30 Mar 2014 23:19:17 EST ID:ZhOAg7La No.53409 Ignore Report Reply Quick Reply
File: 1396235957344.jpg -(1526332B / 1.46MB, 1728x1224) Thumbnail displayed, click image for full size. 1526332
OK, odd question but...well marijuana is what...

Here we go - Is a non-stellar black hole theorhetically possible?
Imagine no restrictions of the creation of it. You have an unlimited supply of dense matter to throw into a big old sphere. Say, I dunno...Iron. Unlimited iron. You can just throw that shit by the teraton into one even pile.

I mean, you could create a black hole eventually, right? It would get really fucking hot at first...molten...then maybe some sort of weird plasma? But we keep throwing on the mass. Using special Future Magic to keep shit contained. You get a black hole at some point, right?
23 posts and 2 images omitted. Click Reply to view.
>>
Arno Penzias - Mon, 09 Feb 2015 11:08:46 EST ID:ZM0jvM6N No.55014 Ignore Report Quick Reply
>>55006
>Supernova*
A nova isn't the same thing as a supernova which involve black holes.

The paper claims it will not impact observations as you get something that is for all practical purposes a black hole. This is a debate for theorists and many have pointed to a number of grand assumptions made on the paper.
>>
Johannes Kepler - Mon, 09 Feb 2015 12:59:51 EST ID:YHjXylC8 No.55015 Ignore Report Quick Reply
>>55014
>you get something that is for all practical purposes a black hole
Where are you reading that? As far as I can tell, it's effectively saying "When we do calculations this way, it says the collapse reverses before the is compressed beyond its Schwarzschild radius, causing everything to explode away."
http://arxiv.org/pdf/1409.1837v1.pdf
>>
Wilhelm Beer - Tue, 10 Feb 2015 13:11:50 EST ID:ZM0jvM6N No.55020 Ignore Report Quick Reply
>>55015
It's from one of the other papers published by the author. I'm not sure if that's still what she thinks.
>>
Robert Dicke - Tue, 10 Feb 2015 23:49:27 EST ID:415JX8nG No.55022 Ignore Report Quick Reply
It doesn't matter what element it is made of, it is strictly a measure of total mass.
A earth mass of iron would be a planet, a solar mass of iron collapses into a neutron star.

Iron nuclei are much more massive than hydrogen and helium, remember the real implications of the periodic table.
>>
Margaret Burbidge - Fri, 13 Feb 2015 19:53:11 EST ID:4HbkLal6 No.55030 Ignore Report Quick Reply
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>the universe started when a bunch of shit got thrown together


If instead of astronomy, young Carl had instead become interested in the culinary arts. by Riccardo Giacconi - Sun, 08 Feb 2015 12:18:46 EST ID:ZmBRgB9c No.55007 Ignore Report Reply Quick Reply
File: 1423415926683.jpg -(61262B / 59.83KB, 315x476) Thumbnail displayed, click image for full size. 61262
DICKS EVERYWHERE
>>
Friedrich Bessel - Sun, 08 Feb 2015 12:59:17 EST ID:4HbkLal6 No.55008 Ignore Report Quick Reply
>>55007
Apple Pie, vol. 84930
>>
Wilhelm Beer - Sun, 08 Feb 2015 18:43:00 EST ID:KCC23SOp No.55009 Ignore Report Quick Reply
http://youtu.be/ZP7K9SycELA

Meat Planet!!!
>>
Whitey Fanwater - Sun, 08 Feb 2015 18:50:39 EST ID:3I5fR38C No.55010 Ignore Report Quick Reply
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>>55007
food would be so much more delicious


Celestron 127EQ by Edwin Hubble - Sun, 04 Jan 2015 18:14:07 EST ID:1FsPM3Cw No.54891 Ignore Report Reply Quick Reply
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I'm gonna start this thread out by saying, this is one of the most appropriately named boards on the web. With that being said, I have had a life long passion for astronomy for 30 years now and I have finally acquired a really good telescope. The Celestron 127EQ is the scope I have (got it last month for my birthday) and it seems to be a rather good investment for a beginner. I do have some troubles though. I got the telescope put together without trouble, but I have trouble with coordinates and with the adjusting of it. I can of course move it around and swivel it, but sometimes it doesn't want to lock into position. If any of you could give me some tips and advice it would be much appreciated. I just really want to get the hang of this hobby so I can begin photographing, the telescope comes with a mount for a camera. Anyway, pic related, this is it.
>>
Henry Russell - Sun, 04 Jan 2015 18:41:21 EST ID:ksAXy5yQ No.54892 Ignore Report Quick Reply
>>54891
I'd say that you need to consult the user manual more closely.

I'm not trying to be a punk but why would random people know how a certain model of telescope works? There's billions and billions of them.

I guess I could suggest tightening all the knobs better but without actually touching the telescope, my guess is as good as yours.
>>
Nicolaus Copernicus - Tue, 13 Jan 2015 02:51:48 EST ID:Dnv5U1Ks No.54905 Ignore Report Quick Reply
Is that pic related? It looks 8"

Invest in a bigger one if you can. You will be glad you did.

nb cuz not helpful
>>
Hannes Alven - Mon, 02 Feb 2015 09:59:16 EST ID:SiTp3J4K No.54983 Ignore Report Quick Reply
just put one of these on it and then point the scope at cool stuff in the sky and look at it through the eye piece

you might want a different mount for it if yours is slipping. it doesn't look like a very good mount...you probably won't be taking many astro photos with it. i have a similar scope on this tripod with steel legs for ultra stability, it's pretty good! - http://www.telescopesandbinoculars.co.uk/acatalog/AZ4-HEAVY-DUTY-ALT-AZIMUTH-MOUNT---TRIPOD-------1606.html
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Hannes Alven - Mon, 02 Feb 2015 10:02:07 EST ID:SiTp3J4K No.54984 Ignore Report Quick Reply
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>>54983
i meant to post this. it's a telrad. they're pretty tight and they're not too spenno...probably one of the best astronomy accessories i've purchased.

also im beginning to learn that a nice set of binoculars is pretty important for backyard astronomy, probably even more important than a scope tbh


m(11) by Kan Li Zhong - Tue, 06 Jan 2015 14:35:49 EST ID:Qrrkgdjp No.54896 Ignore Report Reply Quick Reply
File: 1420572949725.jpg -(42642B / 41.64KB, 569x350) Thumbnail displayed, click image for full size. 42642
cyanide in space (toward galactic core)
waxy cyanide in space (toward galactic core)
cyanide on Mars (furthest from Sol than Earth)
Radioactive Water (Diduetrium Oxide)
Watery super planets near the Galactic Core
Cold, Rogue Gas Giants (No detected host star) opposite of Glesian superplanets


after a little research using Twitter I'll find the location of Mars at the point of Curiosity's recent discovery.
>>
Karl von Weizsacker - Tue, 06 Jan 2015 23:52:25 EST ID:L6PvDKDA No.54900 Ignore Report Quick Reply
> Radioactive Water (Diduetrium Oxide)
What? Heavy water isn't radioactive, though it's used in some types of reactors. What are you on about anyway? nb


cool video by Walter Baade - Tue, 06 Jan 2015 00:15:08 EST ID:415JX8nG No.54895 Ignore Report Reply Quick Reply
File: 1420521308940.jpg -(33070B / 32.29KB, 640x467) Thumbnail displayed, click image for full size. 33070
Here's a cool video on quantum mechanics I found, there's no hard math in it, but it really made me see things in a different way.
youtube.com/?reload=7&rdm=1cbzr13i6#/watch?v=BFvJOZ51tmc

It revolves around the famous debate between Bohr and Einstein over really their philosophies on the fundamental nature of reality. But it really drove home to me a lot of principals of quantum mechanics.

Picture is of the election shell around a hydrogen atom
Also: General far out stuff thread
>>
Walter Baade - Tue, 06 Jan 2015 15:21:45 EST ID:H3af7FdZ No.54897 Ignore Report Quick Reply
https://www.youtube.com/watch?v=BFvJOZ51tmc


Worlds Largest Optical Telescope Gets Green Light by Urbain Le Verrier - Tue, 09 Dec 2014 19:35:39 EST ID:CSHK8ujB No.54790 Ignore Report Reply Quick Reply
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The European Extremely Large Telescope (E-ELT), a planned 39 meter telescope to be built high in the atacama desert has received sufficient funding to move into implementation. The observatory aims for first light around 2024.

http://www.eso.org/public/images/eso1440a/

At 39 meters the telescope will dwarf the current 8-10 meter class telescopes with 4 times the resolution and about 15 times the collecting area.

The telescope evolves around several science themes from large to small. It's extreme resolution combines will provide Hubble like views of galaxies 30 times further away but also with the power to resolve every pixel into a spectrum. This will mean a great deal for galaxy formation.

On the topic of exoplanets E-ELT will have a high precision spectrograph capable of confidently detecting earth like planets around sun like stars. With later instruments it will also be capable of directly imaging super-earths. With time it could provide evidence of continents and oceans.

It's high precision spectrograph of directly measuring the expansion of the universe for the first time. Redshift drift is an effect where the expansion of the universe causes redshifts to slowly increase over time.

E-ELT boasts big science and some incredible engineering.
9 posts and 1 images omitted. Click Reply to view.
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Thomas Henderson - Fri, 12 Dec 2014 12:50:19 EST ID:YHjXylC8 No.54809 Ignore Report Quick Reply
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Science is done by scientists. They're not trying to sell people products, forming committees to come up with better names names for things don't get us any closer to mars.

>>54805
Then what are we going to call a device that detects Oort-cloud objects?


HST image 7A24F will resolve a very large region of sky at a very high resolution. It'll be the largest compilation of images at this resolution anyone's done in awhile.
Other telescopes just look at the surface, the Hubble looks deeper. We'll call it "Deep Field"

This one can see even further.
..."Ultra Deep field"?

>Enhance
This one can nearly see back the the start of the universe.
Fuck it, Call it "Deep Field Extreme. But capitalize the X.
>>
Anders Angstrom - Fri, 12 Dec 2014 13:09:24 EST ID:H3af7FdZ No.54810 Ignore Report Quick Reply
for a moment I thought it was called Worlds Largest Optical Telescope
this is indeed getting retarded, whats wrong with John or Bill?
>>
Kiyotsugu Hirayama - Fri, 12 Dec 2014 15:02:50 EST ID:CSHK8ujB No.54811 Ignore Report Quick Reply
>>54809
Nice post, tiny nitpic. The deep fields are actually a very small region of the sky.
>>
John Bahcall - Mon, 05 Jan 2015 04:07:37 EST ID:uAV78rGD No.54893 Ignore Report Quick Reply
Does it get red, blue, infrared and ultraviolet light too?
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John Wheeler - Mon, 05 Jan 2015 23:21:24 EST ID:CSHK8ujB No.54894 Ignore Report Quick Reply
>>54893
Yes. Initially the instumentation will focus on the near infrared because adaptive optics is easier there and so you get the most out of the telescope. Possibly with a mid infrared camera also. After that visible and UV will come in.


Panspermia by Walter Adams - Mon, 29 Dec 2014 16:10:02 EST ID:h1NupmlQ No.54865 Ignore Report Reply Quick Reply
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Oh shit. I just realized that panspermia is plausible. For those here who dont know, Panspermia basically explains that the building blocks for life, or even micro-organisms came originally from some extra-terrestrials source [read: Not "aliens" per se].

The way I came to this self realization is by reading about the Voyager & Pioneer crafts, and this page from What If:

https://what-if.xkcd.com/117/

So according to this author, whom I would say is slightly reliable if not on the optimistic side, there are a number of microorganisms that remain viable upon spacecraft after launch. Even though most craft are decontaminated, there are still some number of organisms left. Now, a number of craft have failed in their missions and impacted planets. Another number of craft have willingly set down upon planets.

Do you think it is possible that there could be cross contamination from earth based organisms on any local celestial bodies, and more, do you believe that if microorganisms contaminated Mars, or Titan, etc. that they could remain viable, or even multiply?
>>
Giovanni Cassini - Wed, 31 Dec 2014 20:56:46 EST ID:ksAXy5yQ No.54878 Ignore Report Quick Reply
>>54865
Just because panspermia is plausible, doesn't mean it happened. I'm not assuming that you meant that but I'm just throwing that out there just in case. Also, if panspermia was the only way that life is formed, we fall into sort of a "turtles all the way down" or "chicken or the egg" infinite-loop kind of paradox.

Regardless, it would be unlikely that a spacecraft would be contaminated by an extremophile hardy enough to survive in those conditions, not saying that one doesn't exist here on Earth. But they are typically found in very extreme locations such as the bottom of the sea floor, deep underground, or in Antarctica.
>>
James Elliott - Thu, 01 Jan 2015 23:18:56 EST ID:XwQwdExC No.54885 Ignore Report Quick Reply
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The 11th episode of the new Cosmos TV series shows a very plausible explanation for the origin of life being Panspermia; I suggest you watch that episode if you are interested in the subject. I made a thread on /sagan/ about this exact same topic early last year, see this post here:
>>53790

I just find it incredibly interesting how we are finding amino acids and other biological building blocks just floating around in space...
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Robert Wilson - Fri, 02 Jan 2015 03:09:47 EST ID:H3af7FdZ No.54886 Ignore Report Quick Reply
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name for this hypothesis contains a word of sexual nature and its meaning can have vulgar, or even sexist overtones to sensitive people
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Annie Cannon - Sat, 03 Jan 2015 00:21:26 EST ID:415JX8nG No.54889 Ignore Report Quick Reply
I think a reasonable to suggest that if panspermia is correct, most habitable places in this solar system should be inhabited.
I think Martian caves, Europas oceans or slush, and I was thinking maybe even volcanoes on titan, there may be liquid water with interesting chemistry going on.

Also, Curiosity detected organic carbon when it burned some soil containing water ice in a sample retrieved a few inches underground. Nothing definitive, but an interesting signal none the less.

Of course not finding life wouldn't necessarily be proof that panspermia didn't happen, but it would imply that life needs more particular conditions to survive.

We are always finding life that pushes the boundaries of what we thought was possible, if life can in fact exist elsewhere in our solar system, it will.


Study finds possible alternative explanation for dark energy by Joseph von Fraunhofer - Tue, 30 Dec 2014 19:38:01 EST ID:ksAXy5yQ No.54870 Ignore Report Reply Quick Reply
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http://phys.org/news/2014-12-alternative-explanation-dark-energy.html
>The predicted effects of time being faster in the past would have the effect of making the plot of supernovas become linear at all distances, which would imply that there is no acceleration in the expansion of the universe. In this scenario there would be no necessity to invoke the existence of dark energy.

So pretty much if this is true, Dark Energy doesn't exist and it's observed effects are really caused by time dilation. Hubble expansion is really just an illusion caused by time slowing as the universe ages. We see acceleration at increased distances because when you look farther away it means you look back in time, and time is actually slowing down.

Also, this would imply that as the state of the acceleration is essentially linear, there will be no Big Rip or Big Crunch because the acceleration is not positive or negative. The universe will likely end in a slow Heat Death.
7 posts and 1 images omitted. Click Reply to view.
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Fritz Zwicky - Wed, 31 Dec 2014 21:01:27 EST ID:XwQwdExC No.54879 Ignore Report Quick Reply
Since the earth (along with the rest of the galaxy) is moving through intergalactic space at nearly 2 million miles per hour, does that mean our galaxy has its own unique amount of time dilation (with respect to other galaxies/celestial structures? Does time run slower in faster-moving galaxies? I mean, does it make a difference whether a galaxy is moving towards/away from your point of reference? For example, could the degree of time dilation in one galaxy appear to be higher when observed from one galaxy, but appear to be lower when observed from another galaxy that is moving in a different direction from the first? If our solar system existed in a different galaxy moving a different direction, would the time on that bizarro-earth run at a different "clock" compared to our Milky-Way Earth?
Does that even make sense? Sorry, time dilation confuses me...

Also, how does light even propagate at all, when anything traveling that fast would have so much time dilation that its time for it would've slowed to basically a complete halt? How can it appear to move at 299,792,458 meters per second when it takes it an infinite amount of years for it to even "experience" one second?
>>
Galileo Galilei - Wed, 31 Dec 2014 21:35:01 EST ID:7d1GyK7j No.54880 Ignore Report Quick Reply
>>54879
>Since the earth (along with the rest of the galaxy) is moving through intergalactic space at nearly 2 million miles per hour, does that mean our galaxy has its own unique amount of time dilation (with respect to other galaxies/celestial structures?
Yes there is time dilation (as long as is not expansion due to the expanding universe). Both galaxies will see the other running slow, that is one of the cornerstones of relativity. Neither is more right than the other in this observation.

>I mean, does it make a difference whether a galaxy is moving towards/away from your point of reference?
It does. This is the Doppler effect, slightly different from time dilation. If something is moving towards you you observe them sped up because the distance the light has to travel from them to you decreases every second so if you were watching a clock tick you would see it run fast. If it was running away it would be slow. This is just like hearing the pitch of an ambulance siren change as it passes you. The important thing about relativity is that the even if it is running perpendicular to the line of sight (getting neither closer nor farther away) there is an observed slowing, this is time dilation.

>For example, could the degree of time dilation in one galaxy appear to be higher when observed from one galaxy, but appear to be lower when observed from another galaxy that is moving in a different direction from the first? If our solar system existed in a different galaxy moving a different direction, would the time on that bizarro-earth run at a different "clock" compared to our Milky-Way Earth?
Yes but the important thing is that time dilation due to velocity is symmetric, they see your clock tick slow, you see their clock tick slow. Different galaxies would see different degrees of time dilation if they had different velocities.

>Also, how does light even propagate at all, when anything traveling that fast would have so much time dilation that its time for it would've slowed to basically a complete halt?
Some people would claim the photon experiences no time, it can propagate because that is not time dilated. However strictly special relativity does not describe time dilation for light. Relativity assumes just two things but one of them is that light is away measured at the same speed in all frames. To calculate time dilation for an object you need a frame traveling alongside the object, not allowed for light.

>>54873
Possibly, possibly not. The universe is either flat or just closed. If it is flat then then there would be no time dilation because the global geometry would be unchanged. Either way it would be very minor accept in the very early universe.
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James Elliott - Thu, 01 Jan 2015 20:38:37 EST ID:XwQwdExC No.54883 Ignore Report Quick Reply
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>>54880
very interesting, thanks for your reply. I find time dilation really fascinating.

About "gravitational time dilation":
What if gravitation was merely a secondary effect of increased time dilation (rather than the other way around, i.e. time dilation being "caused" by increased gravity), with objects having a natural tendency to gravitate towards regions of spacetime with slower time? Do you think this is at all possible?

Even a spaceship traveling at a significant fraction of the speed of light would have greatly increased mass (according to E=mc^2), and therefore would also have a greatly increased gravitational field. In this case, the increased gravity would act like natural "drag" to slow the velocity of the spacecraft down to a more neutral speed (with respect to other moving bodies in the universe). Is it at all plausible to consider that gravity may be a "fictitious force" like we consider the centripetal force to be?

sorry if these are dumb questions
>>
Giovanni Cassini - Fri, 02 Jan 2015 08:47:54 EST ID:ksAXy5yQ No.54887 Ignore Report Quick Reply
>>54883
If anything, things would seem to move away faster as they move into space that experiences a faster time rate. Oh wait, they already do and this is why we think there's dark energy.

All this still doesn't explain dark matter.
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Henry Russell - Sun, 04 Jan 2015 14:25:15 EST ID:ksAXy5yQ No.54890 Ignore Report Quick Reply
>>54887
Thought experiment, feel free to dismiss this as nonsense.

What if dark matter is somehow linked to the apparent mass increase objects experience as they approach light speed?

In localized areas where the time is not moving faster, objects to not seem to have any increased mass. But more distant objects, which are relatively moving faster and faster away from us approaching light speed more and more, objects are actually apparently gaining mass due to general relativity.

This could be tested by measuring the mass of extremely distant objects over time but I'm afraid it would take too much time, in human years, to observe a change.


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