Universe Has 100x More Entropy Than We Thought

eldavojohn writes "Previous estimates are now thought to skimp on the entropy of the observable universe. The researchers contend that super-massive black holes are the largest contributor of entropy. Since they contribute two orders of magnitude more than previously thought, the total of all the observable universe is correspondingly higher. The paper highlights (in gruesome detail) new issues that arise with these new calculations — like estimating us a little bit closer to heat death (moving entropy totals from 10^102 to 10^104 out of a maximum of 10^122)."

Comments

Heat Death

[Anonymous Coward]

Here's a link for anyone curious about the Heat Death of the Universe concept

Re:Heat Death

[MozeeToby]

It's interesting to note that even with the new estimate being 100X greater than the old, the new data is still only a billionth of a billionth of the maximum value. What, if anything, does that mean for the past and future of the universe? Reminds me of the Stephen Baxter book Manifold: Time, where the age of stars and galaxies is thought of in the same way we think of the instant right after the big bang.

Re:Heat Death

[SlashdotOgre]

Coincidentally, the Ask Slashdot regarding SciFi works for students lead me to Isaac Asimov's cool short story "The Last Question" (http://www.multivax.com/last_question.html which has an interesting perspective on this...

Re:Heat Death

[commodore64_love]

>>>What, if anything, does that mean for the past and future of the universe?

There was a Doctor Who TNG episode about this. The universe at the point of heat death was a sad and depressing place to be... very very dark To paraphrase Marvin the Depressed Robot - Might as well slit my wrist now, since it will all end in tears anyhow.

Now the world has gone to bed
Darkness won't engulf my head
I can see by infra-red
How I hate the night

Fourth Law

[T.E.D.]

I propose a Fourth Law of Thermodynamics: There's more entropy than you think there is.

Re:Fourth Law

[Aphoxema]

Fourth Law of Thermdynamics: There's always more entropy then you think there is, even when you take into account the Fourth Law of Thermodynamics.

I still wouldn't worry about the heat death of the universe, though, unlike those in the aforementioned link.

You forgot to recursively account for the fourth law, you fool! The death of the universe will now be exponentially sooner every moment that passes!

Re:Excellent!

[Afforess]

It self-destructs, correct?

discovery

[unjedai]

Universe Has 100x More Entropy Than We Thought

Scientists must have discovered my daughters room.

Re:discovery

[royallthefourth]

Universe Has 100x More Entropy Than We Thought

Scientists must have discovered my daughters room.

No, but the football team sure has!

Re:discovery

[ObsessiveMathsFreak]

Football plays and players clearly show that simple bodies can form spontaneous order. This result was found to be in direct opposition to the prevailing dogma of the second law of teenodynamics; That the disorder of a teenagers life, property, and living space will always increase over time. This breakthrough is thought to have bearing on the great problem of "Teenage dysfunction death" which asks why when teenagers continuously degenerate over the course of their teen years, so they eventually mature into productive and stable adults.

Scientists urge caution in relation to these findings. "Current teenage theory leaves many questions unanswered", said Professor Alex Tweed of the national institute for Juvenile Entropy studies, "However, one result does not explain all the data on its own. For example, we know that there are quite a few adults who never become stable or mature. For example, many can be found making tasteless jokes about peoples' daughters on web forums, and other can be found modding up those same comments. This field will require more research before a definitive understanding of human maturity is achieved."

we're doomed anyway

[prgrmr]

Because of Neutron decay we've only 10^49 years anyway.

Re:Black holes contribute to entropy ?

[Colonel Korn]

Everything that comes into a black hole comes back out eventually via Hawking Radiation. It goes in as a star or a chicken or a pistachio and comes out as random energy, which is a pretty clear increase in entropy.

Re:Excellent!

[FlyingSquidStudios]

No, it merely reaches a state of equilibrium, so it never fires.

Re:MC Hawking on Entropy

[vivin]

The researchers contend that super-massive black holes are the largest contributor of entropy.

I have also heard that "glaciers melting in the dead of night" contribute to entropy quite a bit.

Re:Black holes contribute to entropy ?

[Lemmy Caution]

"Order" and "disorder" are human perceptions, not states of matter and energy. Sometimes we perceive more order when there are clear differences in energy states, sometimes we perceive less

To you, which is more ordered: a bowl of cherries next to a glass of water, or a completely smooth blend of all of them? The latter is more entropic. In the case of the room, replace the garbage bin with an incinerator, and the "empty" room (plus the stuff that used to be in it) is now in a more entropic state. The fact that you personally find it tidier isn't relevant. Assuming that you might have actually needed some of the stuff that we just burned, too, you might find it a rather poor solution to the problem of a messy room.

Re:You down with entropy?

[mcgrew]

Wow, Vogons posting on slashdot!

Re:Any astrophysics geeks out there

[ArcCoyote]

being haughty to AC is like shouting at a tree because a squirrel annoyed you.

Re:What's the big deal?

[mea37]

I'm afraid the BAC analogy really isn't appilcable. You're describing an impurity which builds up to a critical level to "kill" the host, and pointing out that if you could sequester the impurity the sequestered quantity wouldn't matter. Entropy is not an impurity that is slowly building up to eventually cause the universe to break; it's nothing like that at all.

I find it conceptually confusing to think about entropy as a finite/positive quantity. The way it's defined mathematically, of course, it is ... but at a physical level there's just something backwards about it.

Entropy describes the degree to which energy in a system isn't usable. If you consider as a closed system a bit of ice in a glass of hot water: the heat in the water is "useful" in this system. It will melt the ice, and then equalize the temperature of the water from the melted ice to that of the rest of the water. (That may not seem "useful"; I suppose the point is other processes could capture and use the energy for other ends.)

But, as the ice melts and the water temperature equalizes (or as any other process fuels itself by accelerating this process), you don't run out of energy (which is constant) - but you do run out of "usability" of energy. When your system contains only water at a fixed temperature, there is no way to make heat flow, and all of teh energy in the system is useless. (Again, this assumesa closed system.)

So the point with black holes is, they aren't sequestering entropy to keep it from harming the universe in some way (like your BAC example); if anything they sequester energy and keep it from interacting with the rest of the universe, rendering it useless. (Not sure how Hawking radiation fits in that analysis, though.)