If you can read this, either the style sheet didn't load or you have an older browser that doesn't support style sheets. Try clearing your browser cache and refreshing the page.

(Live Science)   Elusive dark energy is still real to scientists, guy in bleachers   (livescience.com) divider line 32
    More: Obvious, dark energy, galaxy clusters, Nobel Prize in Physics, gravitational lensing, cosmic microwave background, expansion of the universe, gravitational fields, Astronomical Society  
•       •       •

1444 clicks; posted to Geek » on 12 Sep 2012 at 6:46 PM (1 year ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



32 Comments   (+0 »)
   
View Voting Results: Smartest and Funniest

Archived thread
 
2012-09-12 06:52:03 PM
i.imgur.com
 
2012-09-12 06:57:01 PM
Well, they still have a problem to solve. They can't find all the mass/energy in the universe that would explain our being here. "Dark matter" was one theory. Didn't work out.

They'll figure it out eventually.
 
2012-09-12 07:00:22 PM

Rent Party: They'll figure it out eventually.


Somebody probably just misplaced a decimal somewhere
 
2012-09-12 07:01:22 PM
Before there was something, there was nothing. This explains alot about Justin Beiber, Kloe Kardashian and Snooki. But does f*ck all to explaining the universe.
 
2012-09-12 07:02:02 PM

tortilla burger: Rent Party: They'll figure it out eventually.

Somebody probably just misplaced a decimal somewhere


Might be that, might be something else entirely.

Point being, science is *supposed* to work this way. It's a good thing!

/ Hey, nice hypothesis you've got there....
 
2012-09-12 07:25:31 PM

Rent Party: Well, they still have a problem to solve. They can't find all the mass/energy in the universe that would explain our being here. "Dark matter" was one theory. Didn't work out.

They'll figure it out eventually.


Huh? Dark matter is still the best explanation for a range of phenomenon (galactic rotation, bullet cluster, etc).
It's sorta like the highs boson. We have information telling us dark matter exists, but we still need to find it.
 
2012-09-12 07:30:40 PM
There's this new stuff called dark energy
We can't measure and we can't see.
 
2012-09-12 07:48:36 PM

ChrisDe: There's this new stuff called dark energy
We can't measure and we can't see.


Sort of like God.
 
2012-09-12 08:09:42 PM

Rent Party: tortilla burger: Rent Party: They'll figure it out eventually.

Somebody probably just misplaced a decimal somewhere

Might be that, might be something else entirely.

Point being, science is *supposed* to work this way. It's a good thing!

/ Hey, nice hypothesis you've got there....


Now that's a pickup line!
 
2012-09-12 08:55:11 PM

Ogre840: / Hey, nice hypothesis you've got there....

Now that's a pickup line!


The follow-up line has to include the term "rigor."
 
2012-09-12 09:19:05 PM
So because the light from the big bang seems to gain energy when it should be losing energy as it passes through matter, we know there is some other force or matter at work. We just don't know what it is.

For some reason, I think the discovery with the LHC will have some impact on this.
 
2012-09-12 09:42:10 PM

ChrisDe: There's this new stuff called dark energy
We can't measure and we can't see.



Can't see it, but we can measure it.
It is even predicted in Quantum Mechanics, but the measured value differs from the predicted amount by so many orders of magnitude that physicist Michio Kaku referred to it as the greatest error in magnitude in the history of physics.
 
2012-09-12 11:16:00 PM
www.comp.nus.edu.sg

/does the window seat come with more vodak?
 
2012-09-12 11:18:04 PM

Cubicle Jockey: physicist Michio Kaku referred to it as the greatest error in magnitude in the history of physics.


www.consolegames.ro
 
2012-09-12 11:54:09 PM

Rent Party: Well, they still have a problem to solve. They can't find all the mass/energy in the universe that would explain our being here. "Dark matter" was one theory. Didn't work out.


You were right up to saying that dark matter didn't work out. Dark energy and dark matter are the "whatever it is" solution to two different problems. Dark matter is "whatever it is" that accounts for the apparent missing mass in our universe. Dark energy on the other hand is the "whatever it is" solution to why is seems like the expansion of our universe is accelerating (positive relative acceleration)


/And by "solution" I mean "placeholder"
//"More quotation marks!" he proclaimed
 
2012-09-13 12:28:37 AM

the_sidewinder: Rent Party: Well, they still have a problem to solve. They can't find all the mass/energy in the universe that would explain our being here. "Dark matter" was one theory. Didn't work out.

You were right up to saying that dark matter didn't work out. Dark energy and dark matter are the "whatever it is" solution to two different problems. Dark matter is "whatever it is" that accounts for the apparent missing mass in our universe. Dark energy on the other hand is the "whatever it is" solution to why is seems like the expansion of our universe is accelerating (positive relative acceleration)


/And by "solution" I mean "placeholder"
//"More quotation marks!" he proclaimed


Well, there ya go. A refined solution to a still unsolved issue, working on previous works, just as Allah and Alhazen intended.

Science! Is there anything it can't do?
 
2012-09-13 03:12:45 AM
we are just on a cusp of a minor wave on a major pond...
 
2012-09-13 03:58:20 AM
Dark energy? Easy to make. Make a diamond block and surround it with aeternalis fuel. dark energy.
 
2012-09-13 07:38:32 AM
The universe is accelerating. For something to accelerate, you must add energy to the system. Dark energy is what we call whatever is causing the acceleration. It certainly exists, in some fashion- we just don't know what it is. We can observe its effects, which when you get down to it, is how we do everything. We don't "see" anything, we observe the effects objects have on light.

Lt. Cheese Weasel: Before there was something, there was nothing.


Not according to physics. There was no point in the history of the universe at which there was nothing.
 
2012-09-13 09:23:56 AM

t3knomanser: The universe is accelerating. For something to accelerate, you must add energy to the system. Dark energy is what we call whatever is causing the acceleration. It certainly exists, in some fashion- we just don't know what it is. We can observe its effects, which when you get down to it, is how we do everything. We don't "see" anything, we observe the effects objects have on light.

Lt. Cheese Weasel: Before there was something, there was nothing.

Not according to physics. There was no point in the history of the universe at which there was nothing.


Considering that time also started at the beginning of the universe, there is technically no "before the beginning."
 
2012-09-13 09:37:14 AM

LoneWolf343: Considering that time also started at the beginning of the univers


I'm a programmer, and as a result, I like to think of spacetime as an addressing system. From a given event in the universe, every other event that ever occurred or will occur can be given an address relative to that event. The address takes 4 components- three to establish its location in space, one to establish its location in time.

Each address is unique- no two events can share the same 4-d address in spacetime. There are also unaddressable events, like for example, the inside of a black hole. There are no spacetime coordinates that we can use out here to address an event in there. The event horizon creates a barrier that limits our ability to meaningfully discuss what occurs inside of a black hole. There is some information that leaks out, certainly, but we still can't address a space-time coordinate inside the black hole. At the event horizon, time inside the black hole stops relative to an observer outside the black hole. It takes an infinite number of seconds outside for one second to pass inside. Now, that's absurd, since we know black holes spin, and spinning takes time. Spacetime cannot accurately describe what happens inside of a black hole.

The birth of the universe has its own event horizon. At some point, the universe was so dense that it would have resembled a black hole to an outside observer. At our point in time, we are outside of that event horizon. Just like a black hole, there's a point where our ability to address points in spacetime fails when we try and address a point on the other side of that event horizon. Once again, spacetime cannot accurately describe what was happening when the Universe was that dense.

Will we one day be able to? I actually think it's possible, but to do so we have to abandon our common-sense ideas of how events relate to each other. Things like multi-dimensional super-strings are one approach to doing that- events can be specified with a larger coordinate system. But even as we build workable, mathematical descriptions of what happens on the other side of an event horizon, terms like "before" and "time" still won't make sense. We'll need highly abstract mathematical concepts to talk about them.

And unfortunately, our ability to experimentally confirm these models will always be bounded by the fact that the speed of light prevents us from peeking beyond an event horizon. Information can leak out of a black hole, but only the information that goes into it. Information about the black hole itself can't be seen, ever.
 
2012-09-13 12:31:32 PM

Rent Party: tortilla burger: Rent Party: They'll figure it out eventually.

Somebody probably just misplaced a decimal somewhere

Might be that, might be something else entirely.

Point being, science is *supposed* to work this way. It's a good thing!

/ Hey, nice hypothesis you've got there....


Be a shame if anything happened to it!

fc07.deviantart.net
 
2012-09-13 01:27:03 PM

t3knomanser: There are no spacetime coordinates that we can use out here to address an event in there. The event horizon creates a barrier that limits our ability to meaningfully discuss what occurs inside of a black hole. There is some information that leaks out, certainly, but we still can't address a space-time coordinate inside the black hole. At the event horizon, time inside the black hole stops relative to an observer outside the black hole. It takes an infinite number of seconds outside for one second to pass inside. Now, that's absurd, since we know black holes spin, and spinning takes time. Spacetime cannot accurately describe what happens inside of a black hole.


That's not correct. Schwarzschild coordinates have a coordinate (not physical) singularity at the event horizon, but not all coordinate systems do. Kruskal-Szekeres coordinates, for example, behave perfectly smoothly across the horizon. Spacetime is perfectly adequate to describe what happens both inside and outside of a black hole (except at the singularity itself, which is not a coordinate artifact but a true break-down of spacetime geometry).
 
2012-09-13 01:45:22 PM

Ambitwistor: That's not correct. Schwarzschild coordinates have a coordinate (not physical) singularity at the event horizon, but not all coordinate systems do. Kruskal-Szekeres coordinates, for example, behave perfectly smoothly across the horizon. Spacetime is perfectly adequate to describe what happens both inside and outside of a black hole (except at the singularity itself, which is not a coordinate artifact but a true break-down of spacetime geometry).


Suskind in "The Black Hole War" talked about how a person could pass through an event horizon and not even know it if the black hole was massive enough. For that individual spacetime is still perfectly normal.

People on the outside observing him would see something completely different, however.
 
2012-09-13 03:27:07 PM

Ambitwistor: (except at the singularity itself, which is not a coordinate artifact but a true break-down of spacetime geometry).


I think that's his point. There are places where our current model effectively goes, "Well fark, I have no goddamn clue". Singularities are one of them. Dark Matter is another. This stuff that theoretically should permeate the universe and is supposed to be gravitationally manipulating everything simply can't be found. There are two options there: one, this supposedly omnipresent stuff is there even though we haven't actually found any yet, or our model of the universe is not, indeed, perfect. Given that we have other areas where our model breaks down, I'm going with option B.

People forget that Dark Matter has never had anywhere near a universal buy in by physicists. The media latched onto the idea and has typically reported it as something scientists are absolutely certain of, but just need more power to find, like the Higgs Boson. That's not really the case.

Rent Party: Well, they still have a problem to solve. They can't find all the mass/energy in the universe that would explain our being here. "Dark matter" was one theory. Didn't work out.

They'll figure it out eventually.


And really, there you go.
 
2012-09-13 04:21:50 PM

cptjeff: Ambitwistor: (except at the singularity itself, which is not a coordinate artifact but a true break-down of spacetime geometry).

I think that's his point.


No, he was talking about the event horizon, not the singularity. It's a common misconception that general relativity's spacetime description breaks down at the event horizon, but this is a mathematical artifact of one popular coordinate system, not of the theory itself.

People forget that Dark Matter has never had anywhere near a universal buy in by physicists.

Speaking as a physicist with a strong background in astrophysics, dark matter is by far the leading candidate among astrophysicists to explain our astronomical observations.
 
2012-09-13 05:41:45 PM

Ambitwistor: That's not correct. Schwarzschild coordinates have a coordinate (not physical) singularity at the event horizon, but not all coordinate systems do


For most common fark-thread purposes, you can get away with treating the event horizon like a singularity. Especially when I can't explain how the Schwarzschild coordinate system works without doing a bunch of reading, first.

cptjeff: There are places where our current model effectively goes, "Well fark, I have no goddamn clue"


That's not really what I'm saying, exactly. I'm saying that spacetime doesn't describe certain scenarios, specifically ones pertaining to singularities. It's not that the model "has no clue"- it doesn't apply in that situation. That's a subtly different statement.

Dark energy isn't one of these cases. Dark energy is a placeholder to describe the unknown cause of an observed phenomenon.
 
2012-09-13 06:51:20 PM

t3knomanser: For most common fark-thread purposes, you can get away with treating the event horizon like a singularity. [...] I'm saying that spacetime doesn't describe certain scenarios, specifically ones pertaining to singularities.


I think we should be clear here that spacetime does describe scenarios at and within event horizons. It only breaks down very close to (within a few Planck distances) of a black hole's central singularity.
 
2012-09-14 09:02:16 AM

Ambitwistor: People forget that Dark Matter has never had anywhere near a universal buy in by physicists.

Speaking as a physicist with a strong background in astrophysics, dark matter is by far the leading candidate among astrophysicists to explain our astronomical observations.


It is weird that so many fark armchair astrophysicists have this distrust of dark matter as an explanation. Any idea on why that may be?
 
2012-09-14 09:48:00 AM

Baryogenesis: Ambitwistor: People forget that Dark Matter has never had anywhere near a universal buy in by physicists.

Speaking as a physicist with a strong background in astrophysics, dark matter is by far the leading candidate among astrophysicists to explain our astronomical observations.

It is weird that so many fark armchair astrophysicists have this distrust of dark matter as an explanation. Any idea on why that may be?


Non-conformity. Leads them to doubt stuff like "matter we know is there but we can't observe."
 
2012-09-14 11:54:37 AM

Baryogenesis: It is weird that so many fark armchair astrophysicists have this distrust of dark matter as an explanation. Any idea on why that may be?


It's pretty common across amateur Internet discussions of dark matter. I think it's largely ignorance -- they're not really aware of the history of the field, the evidence, and the failures of alternative theories, all of which dragged the astrophysics community toward consensus on the matter. It took decades, so it's not like everybody jumped on board for faddish reasons. They had to be convinced. But people don't know that, and think there's less consensus than there really is.

But also I think there's a bit of LoneWolf343's explanation, in that people like to be iconoclasts, and without a deep understanding of the field they're able to preserve their contrarian views.

I see parallels in other anti-science debates (evolution, climate change, etc.).
 
2012-09-14 05:34:26 PM

Ambitwistor: But also I think there's a bit of LoneWolf343's explanation, in that people like to be iconoclasts, and without a deep understanding of the field they're able to preserve their contrarian views.

I see parallels in other anti-science debates (evolution, climate change, etc.).


I was really hoping that wasn't a primary explanation. Sigh
 
Displayed 32 of 32 comments

View Voting Results: Smartest and Funniest


This thread is archived, and closed to new comments.

Continue Farking
Submit a Link »





Report