Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: watsisname on March 25, 2013, 02:51:47 am
-
Here is the finest baby picture of the universe we can possibly get:
(http://i.imgur.com/RAAw96E.jpg)
Results show that the universe has less dark energy than previously thought (68-69%), more dark matter (26%), and slightly more baryonic matter (4.9%). The Hubble Constant is now put at 67.3 ± 1.2 km/s/Mpc, which is on the extreme low end of the WMAP estimates. These factors in turn mean that the age of the universe is slightly older than previously estimated, at 13.81 billion years. (Previously ~13.74).
Other finds:
No spatial curvature.
No extra types of neutrinos.
Strong evidence of inflation, but details on constraining the different possible types remains to be seen from polarization data.
More discussion may be found here (http://scienceblogs.com/startswithabang/2013/03/21/what-the-entire-universe-is-made-of-thanks-to-planck/).
-
still flat baby. still full of tegmark Is :getin:
-
I thought it was (currently) impossible to measure dark energy, let alone prove (in any fashion) that it existed. :wtf:
Did I miss something big or do all news organizations REALLY suck that much?
-
I thought it was (currently) impossible to measure dark energy, let alone prove (in any fashion) that it existed. :wtf:
Did I miss something big or do all news organizations REALLY suck that much?
You're - not wrong, but in a way you've also been wrong all along. Dark energy cannot yet be directly observed. The reason we believe in its existence, however, is because we can observe its effects on the universe. By updating our knowledge of the early universe (and I use the Bayesian 'updating' very purposefully here), we can also update our mathematical projections as to the exact mix of baryonic matter, dark matter, and dark energy.
Dark energy is in sort of the same place the Higgs boson has been for a long time: the math predicts it, but we don't have the means to actually observe it directly (or even secondhand) yet. This might sound kind of roundabout and sketchy, but it's currently the best and simplest hypothesis we have to explain our observations.
-
I feel like I should expand: in an isotropic and homogenous universe with no dark matter, we can predict the curvature of the universe purely from the density of matter in space. To the extent that this curvature seems to depart from that suggested by the density of (baryonic) matter in space, we know we need additional factors. Dark energy comes into play not only in this domain but in explaining the observed Hubble constant. We need to introduce inflation as well to explain the timeline of the early universe.
-
Correct, the existence of dark energy has observable consequences on the evolution of the universe. Practically speaking, we can measure the relative abundances of matter / dark matter / dark energy because they affect the CMB angular power spectrum (http://www.jodrellbank.manchester.ac.uk/research/cosmos/vsa/CMB_power_spec.html), i.e. the relative sizes of the fluctuations in the CMB. The power-spectrum is amazingly rich in information, and is a huge reason why we have spent so much effort on getting increasingly high-resolution maps of this radiation field. The Planck data is about as good as we can possibly hope for. :)
Edit: I'm curious to find out if this puts better constraints on the future evolution of the universe. Will there be a Big Rip? :shaking:
-
I was wondering when this would show up here!
I need to have a chat with the guys who did the receiver, there's surely some meaty stuff there...
-
Correct, the existence of dark energy has observable consequences on the evolution of the universe. Practically speaking, we can measure the relative abundances of matter / dark matter / dark energy because they affect the CMB angular power spectrum (http://www.jodrellbank.manchester.ac.uk/research/cosmos/vsa/CMB_power_spec.html), i.e. the relative sizes of the fluctuations in the CMB. The power-spectrum is amazingly rich in information, and is a huge reason why we have spent so much effort on getting increasingly high-resolution maps of this radiation field. The Planck data is about as good as we can possibly hope for. :)
Edit: I'm curious to find out if this puts better constraints on the future evolution of the universe. Will there be a Big Rip? :shaking:
There is nothing that fills me with more dread than the concept of the eternal end of all life.
-
Why? It'll be almost infinitely long after any of us cease to exist, at least from our own limited perspectives. :p
D'awww, the universe was so cute at that age!
-
Am I the only one that see the thing bulging? :shaking:
-
There is nothing that fills me with more dread than the concept of the eternal end of all life.
This is a very fun philosophical topic. :)
Am I the only one that see the thing bulging? :shaking:
Congratulations, it's a girl. No wait, it's a universe? How did that get in there? Get out, you don't even fit!
-
Correct, the existence of dark energy has observable consequences on the evolution of the universe. Practically speaking, we can measure the relative abundances of matter / dark matter / dark energy because they affect the CMB angular power spectrum (http://www.jodrellbank.manchester.ac.uk/research/cosmos/vsa/CMB_power_spec.html), i.e. the relative sizes of the fluctuations in the CMB. The power-spectrum is amazingly rich in information, and is a huge reason why we have spent so much effort on getting increasingly high-resolution maps of this radiation field. The Planck data is about as good as we can possibly hope for. :)
Edit: I'm curious to find out if this puts better constraints on the future evolution of the universe. Will there be a Big Rip? :shaking:
There is nothing that fills me with more dread than the concept of the eternal end of all life.
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
-
Thanks man, I was totally looking for a new cosmic fear. :blah:
-
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
There is another theory which states that this has already happened. :p
Seriously, though. If we existed inside the expanding bubble of a metastatic vacuum collapse event, what would it look like? I don't know enough math or physics to do much more than wild speculation, but is it even remotely possible that the expanding bubble of a metastatic vacuum event would look like our expanding universe, if observed from inside the bubble?
-
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
There is another theory which states that this has already happened. :p
Seriously, though. If we existed inside the expanding bubble of a metastatic vacuum collapse event, what would it look like? I don't know enough math or physics to do much more than wild speculation, but is it even remotely possible that the expanding bubble of a metastatic vacuum event would look like our expanding universe, if observed from inside the bubble?
Someone did a depressing paper a while back demonstrating that no life (of any conceivable sort) would be possible after a VME.
The universe at the macro scale is actually nicely proofed against these events, since it expands at speeds faster than light given sufficient distance, and the expansion of the true vacuum bubble is restricted to C.
-
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
There is another theory which states that this has already happened. :p
Seriously, though. If we existed inside the expanding bubble of a metastatic vacuum collapse event, what would it look like? I don't know enough math or physics to do much more than wild speculation, but is it even remotely possible that the expanding bubble of a metastatic vacuum event would look like our expanding universe, if observed from inside the bubble?
Someone did a depressing paper a while back demonstrating that no life (of any conceivable sort) would be possible after a VME.
The universe at the macro scale is actually nicely proofed against these events, since it expands at speeds faster than light given sufficient distance, and the expansion of the true vacuum bubble is restricted to C.
What difference does it make? Everything dies forever either way.Why? It'll be almost infinitely long after any of us cease to exist, at least from our own limited perspectives. :p
D'awww, the universe was so cute at that age!
I like to hold out hope that in some way, whatever came together to give me consciousness and control of this collection of living cells that is me could somehow form again after my inevitable end.
Even if I knew for certain that I am finished forever after I die, I would still like to know life will continue to grow and flourish after I am gone. Even if it has to start over (I am aware of entropy) and keep starting over. Otherwise, it's just profoundly wrong to me.
-
The part of the article that makes me awe is this one:
In the early 1990s, the COBE satellite gave us the first precision, all-sky map of the cosmic microwave background, down to a resolution of about 7 degrees. About a decade ago, WMAP managed to get that down to about half-a-degree resolution.
But Planck? Planck is so sensitive that the limits to what it can see aren’t set by instruments, but by the fundamental astrophysics of the Universe itself! In other words, it will be impossible to ever take better pictures of this stage of the Universe than Planck has already taken.
So we've reached an endgame scenario regarding these images?
-
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
There is another theory which states that this has already happened. :p
Seriously, though. If we existed inside the expanding bubble of a metastatic vacuum collapse event, what would it look like? I don't know enough math or physics to do much more than wild speculation, but is it even remotely possible that the expanding bubble of a metastatic vacuum event would look like our expanding universe, if observed from inside the bubble?
Someone did a depressing paper a while back demonstrating that no life (of any conceivable sort) would be possible after a VME.
The universe at the macro scale is actually nicely proofed against these events, since it expands at speeds faster than light given sufficient distance, and the expansion of the true vacuum bubble is restricted to C.
What difference does it make? Everything dies forever either way.
Incorrect! You've rather missed the point.
-
Amateurs are scared of end state scenarios. Pros are scared of vacuum metastability events (http://i.somethingawful.com/forumsystem/emoticons/emot-aaaaa.gif)
There is another theory which states that this has already happened. :p
Seriously, though. If we existed inside the expanding bubble of a metastatic vacuum collapse event, what would it look like? I don't know enough math or physics to do much more than wild speculation, but is it even remotely possible that the expanding bubble of a metastatic vacuum event would look like our expanding universe, if observed from inside the bubble?
Someone did a depressing paper a while back demonstrating that no life (of any conceivable sort) would be possible after a VME.
The universe at the macro scale is actually nicely proofed against these events, since it expands at speeds faster than light given sufficient distance, and the expansion of the true vacuum bubble is restricted to C.
What difference does it make? Everything dies forever either way.
Incorrect! You've rather missed the point.
Which is? Was it just a joke?
-
Nope
-
The part of the article that makes me awe is this one:
In the early 1990s, the COBE satellite gave us the first precision, all-sky map of the cosmic microwave background, down to a resolution of about 7 degrees. About a decade ago, WMAP managed to get that down to about half-a-degree resolution.
But Planck? Planck is so sensitive that the limits to what it can see aren’t set by instruments, but by the fundamental astrophysics of the Universe itself! In other words, it will be impossible to ever take better pictures of this stage of the Universe than Planck has already taken.
So we've reached an endgame scenario regarding these images?
In terms of the angular power spectrum, probably yes -- higher resolution observations will not result in more meaningful data. However this might not be the case for polarization or other things. I would hesitate to say that we've reached an endgame in terms of knowledge we can gain from the CMB.
edit: By the way, Battuta, I would like it if we could be a little less perfunctory with our responses here. If someone has trouble comprehending something, and asks about it, try to help them to understand it. (I'd try to explain it myself, but things like false-vacuum decay are way outside of my comfort zone.)
-
I'm not sure what Lorric is thinking, but my perspective is that even if the expansion of the universe is sufficient that parts of it could outrun a VME bubble, that expansion itself is going to eventually make all life as we understand it in the universe impossible anyway either via a Big Rip or Heat Death depending on how exactly various cosmological constants (are they really constant?) turn out.
Either way, this universe does not appear to be built to last indefinitely. That is troubling on a fundamental level. It means that everything ever accomplished by any life anywhere in the universe will eventually reach a point beyond which there can be no memory, nor even evidence that it even occurred. It will be like it all never happened.
I suppose either of those outcomes are better than a VME, though, in that they are in the distant cosmological future. A VME could have already occurred, and we wouldn't even know it is rushing in to wipe us out.
Also, I skimmed through the article I believe you referenced earlier. (Gravitational effects on and of vacuum decay, Coleman and De Luccia?) The math goes way over my head, but if I'm understanding the paper correctly, they did analyze the case where we are living in a "post-apocalyptic" universe in which a decay from false vacuum already occurred. They don't really talk about that one as much as they do the one where we currently living in a false vacuum, and their talk on it towards the end is so brief I'm not taking away much. But what I do see is that, in that case, the universe inside the bubble is not subject to unstable gravitational collapse like the one in which we're currently in a pre-apocalyptic false vacuum. So, I'm not seeing anything just yet that states categorically that we cannot be living inside a universe that has already gone through a VME.
But I'm very much just an interested layman researching for fun in his spare (HA!) time. I'd be interested in everyone else's thoughts.
-
The latest delusions from our pet Kardashian have been split out.
-
Nope
Helpful one, aren't you.
Alright, one more try.
Is the point that this event could potentially end our lives, while the other ones won't? If so, it's just one of a million things that could end my life. It's the eternal end that's the big worry, so it makes no difference whether it happens now or an unfathomable length of time into the future. At least I won't see it coming or know anything about it if it does happen.
-
Stop making this thread about Lorric, start talking about cool **** again.
Interestingly, recent developments on the Higgs boson seem to put it in a mass range that boosts the probability we're living in a false vacuum. I suggest we build a super sick accelerator to poke the false vacuum.
-
I've split out the nonsense I was responsible for.
-
All this stuff makes me wish I had time to go back to school and take some classes on physics and cosmology so I could get at all of this from the mathematical side. As it sits, I just don't have the background. The deepest into QED I ever got was statistical mechanics, specifically as it deals with thermo and spectroscopy, and I was dumped into that without having all the primer courses I needed.
Dadgum all this having to go to work and get paid! [shakes fist at sky]
Is there any conjecture as to what properties of the universe could be implied from CMB polarization data, if we had it?
-
We do have it, it's just still being analyzed. It will give us more insight on the nature of inflation, for one thing. :)
Here's a reasonably good primer on the topic if you're interested. (http://cosmology.berkeley.edu/~yuki/CMBpol/CMBpol.htm)
-
Very much interested! Thanks for the link.
-
Apparently, it took 10 years to develop the low frequency detector with a custom process, the waveguides between the back end and the front end amplifiers are something like half a meter long! I haven't talked about this yet with a certain colleague of mine who was in the group building that receiver, but I'll hopefully hear some good stuff from the horse's mouth, at least the company newsletter had some brief mentions of the thing being extremely sensitive - so sensitive that it was extraordinarily difficult to test it with not much more information added to it... Apparently, that receiver is the most sensitive device ever built for that purpose!
But yes, it is the best picture we can get using these frequencies, and there is no way to improve it due to limits from Physics itself. Ever (ooh, this is such a deliciously dangerous word to be used here). Staggering, isn't it? :D
But I'm glad that the Planck mission is a success, with both scientific and technological terms. For me, the biggest thing appears to be the non-uniformity of the background noise and apparently it has now been confirmed that this HAS to be taken into account.
Shame that it's just such a long time since I have last read General Relativity that I have already forgotten most of it!