Time Likely To End Within Earth's Lifespan

[Grat3fulh3ad]

Another interesting take on things:

Look out into space and the signs are plain to see. The universe began in a Big Bang event some 13 billion years ago and has been expanding ever since. And the best evidence from the distance reaches of the cosmos is that this expansion is accelerating.

That has an important but unavoidable consequence: it means the universe will expand forever. And a universe that expands forever is infinite and eternal.

Today, a group of physicists rebel against this idea. They say an infinitely expanding universe cannot be so because the laws of physics do not work in an infinite cosmos. For these laws to make any sense, the universe must end, say Raphael Bousso at the University of California, Berkeley and few pals. And they have calculated when that is most likely to happen.

Their argument is deceptively simple and surprisingly powerful. Here's how it goes. If the universe lasts forever, then any event that can happen, will happen, no matter how unlikely. In fact, this event will happen an infinite number of times.

This leads to a problem. When there are an infinite number of instances of every possible observation, it becomes impossible to determine the probabilities of any of these events occurring. And when that happens, the laws of physics simply don't apply. They just break down. "This is known as the "measure problem" of eternal inflation," say Bousso and buddies.

In effect, these guys are saying that the laws of physics abhor an eternal universe.

The only way out of this conundrum is to hypothesise some kind of catastrophe that brings an end to the universe. Then all the probabilities make sense again and the laws of physics regain their power.

When might his be? Bousso and co have crunched the numbers. "Time is unlikely to end in our lifetime, but there is a 50% chance that time will end within the next 3.7 billion years," they say.

That's not so long! It means that the end of the time is likely to happen within the lifetime of the Earth and the Sun.

But Buosso and co have some comforting news too. They don't know what kind of catastrophe will cause the end of time but they do say that we won't see it coming. They point out that if we were to observe the end of time in any other part of the universe we would have to be causally ahead of it, which is unlikely.

In other words we'll run headlong into this catastrophe before we can observe its effects on anything else.

The imminent end of time is a little unsettling but the argument is by no means water tight. Among other things it depends crucially on an important assumption about the laws of physics: that we ought to be able to understand why they work, not just observe that they do work. And that's a philosophical point of view rather than a physical argument.

So Buosso and buddies raise some interesting questions but nothing to lose any sleep over. At least, not for another 3.7 billion years.

 

[BrainSellz]

3.7 billion years.

so hard to wrap the mind around how long that would be or feel like.

 

[Bulldog11]

Superman is going to be pissed in 3.7 billion years, he thought he would live forever.

On a real note, the laws of physics is still just a theory. Theory's change. We just don't know enough to make these guesses.

 

[DiscoBiscuit]

A physical law or scientific law is a scientific generalization based on empirical observations of physical behaviour (i.e. the law of nature [1]). Laws of nature are observable. Scientific laws are empirical, describing observable patterns. Empirical laws are typically conclusions based on repeated scientific experiments and simple observations, over many years, and which have become accepted universally within the scientific community.

http://en.wikipedia.org/wiki/Physical_law

 

[Grat3fulh3ad]

I hate the phrase "whatever" is just a theory.
so misleading to those who think that theory means guess.
hypothesis means guess, to scientists "theories" are things that are well substantiated and supported by all of the available facts.


All science is theory, but there are theories which such a high degree of probability that they should be treated as fact.

the Heliocentric theory is just a theory.
the Theory of gravity is just a theory.
the Germ theory of disease is just a theory.
the theory of plate tectonics is just a theory.

fortunately in science 'just a theory' is a difficult status to achieve.

most of the foundational theories of science have been proven to such a high degree of probability and are based on such a large body of evidence that no new discovery has any statistically significant possibility of altering the theory at all.


Additionally.
Physics is a branch of science which is made up of many theories and laws.
the laws of physics is not a just theory.


The Laws Underlying The Physics of Everyday Life Are Completely Understood

Not sure why people don’t make a bigger deal out of this fact. Physicists (and scientists more generally) are infamous for making grandiose claims about how close we are to Figuring It All Out, only to be shocked by some sort of revolutionary discoveries soon thereafter. Personally I have no idea how close we are to a comprehensive theory of absolutely everything. But I do know how close we are to having a comprehensive theory of the basic laws underlying the phenomena we encounter in our everyday lives — without benefit of fancy telescopes or particle accelerators or what have you. Namely, we already have it! That seems to be worth celebrating, or at least remarking upon, but you don’t hear it mentioned very much.

Obviously there are plenty of things we don’t understand. We don’t know how to quantize gravity, or what the dark matter is, or what breaks electroweak symmetry. But we don’t need to know any of those things to account for the world that is immediately apparent to us. We certainly don’t have anything close to a complete understanding of how the basic laws actually play out in the real world — we don’t understand high-temperature superconductivity, or for that matter human consciousness, or a cure for cancer, or predicting the weather, or how best to regulate our financial system. But these are manifestations of the underlying laws, not signs that our understanding of the laws are incomplete. Nobody thinks we’re going to have to invent new elementary particles or forces in order to understand high-Tc superconductivity, much less predicting the weather.

All we need to account for everything we see in our everyday lives are a handful of particles — electrons, protons, and neutrons — interacting via a few forces — the nuclear forces, gravity, and electromagnetism — subject to the basic rules of quantum mechanics and general relativity. You can substitute up and down quarks for protons and neutrons if you like, but most of us don’t notice the substructure of nucleons on a daily basis. That’s a remarkably short list of ingredients, to account for all the marvelous diversity of things we see in the world.

A hundred years ago it would have been easy to ask a basic question to which physics couldn’t provide a satisfying answer. “What keeps this table from collapsing?” “Why are there different elements?” “What kind of signal travels from the brain to your muscles?” But now we understand all that stuff. (Again, not the detailed way in which everything plays out, but the underlying principles.) Fifty years ago we more or less had it figured out, depending on how picky you want to be about the nuclear forces. But there’s no question that the human goal of figuring out the basic rules by which the easily observable world works was one that was achieved once and for all in the twentieth century.

You might question the “once and for all” part of that formulation, but it’s solid. Of course revolutions can always happen, but there’s every reason to believe that our current understanding is complete within the everyday realm. Using the framework of quantum field theory — which we have no reason to doubt in this regime — we can classify the kinds of new particles and forces that could conceivably exist, and go look for them. It’s absolutely possible that such particles and forces do exist, but they must be hidden from us somehow: either the particles are too massive to be produced, or decay too quickly to be detected, or interact too weakly to influence ordinary matter; and the forces are either too weak or too short-range to be noticed. In any of those cases, if they can’t be found by our current techniques, they are also unable to influence what we see in our everyday lives. We have very little idea how big the region of our understanding is, compared to all that there is to be understood; but we know that it’s bigger than what we need to understand to make sense of the world we see with our unaided senses.

That’s pretty amazing. Science will certainly push forward along the frontier of phenomena that are too big or small or subtle to be detected without delicate instruments, as well as along the much more jagged and unpredictable frontier of how the basic laws play out in complicated ways. But getting the basic laws right is an extremely impressive accomplishment, especially for good old human beings who have only been doing science systematically for a few centuries. Way to go, human beings

!

http://blogs.discovermagazine.com/co...ly-understood/

 

[BiG H3rB Tr3E]

id be suprised if human exsistance made it another 1000 years..... 3 billion years from now? if humans are still around there better be some shit from the jetsons available....

 

[DiscoBiscuit]

There's still nothing to keep Jane from swiping all of George's money.

 

[Bionic]

The title of the thread is misleading. The scientists say that there is a 50% chance of time ending within Earth's lifespan or 3.7 billion yrs. It's a crap-shoot and no one has any idea what that would mean anyway. I hope no $$$ was spent on this "research."

 

[InvisibleEmpire]

There's a quote, can't pinpoint it right now, but something along the lines of true enlightenment only comes when you realize that you know nothing.

We have theories, and they change often.

When I begin to think about this kind of stuff, the stars, light, the universe, time...I follow my faith.

 

[Grat3fulh3ad]

yup... 50% likely.

 

[Feyd]

well, apparently the earth will be a lifeless rock well before that 3.7billion years, i think i heard that in 2 billion, after plate tectonics have stopped and we lose our atmosphere, the earth will basically look like mars.

but if time is going to end, is it going to repeat itself? is time going to just be an infinite loop?

are we going to die, and then all of a sudden skip the billions of years of unawareness, and then just relive our lives without knowing we are reliving it?
can anything change?

i hope not.
there are a lot of times when i could have gotten laid/head and didnt.
i would not want to go through the regret again.

yup... 50% likely.

and 50% unlikely!

 

[Grat3fulh3ad]

There's a quote, can't pinpoint it right now, but something along the lines of true enlightenment only comes when you realize that you know nothing.

We have theories, and they change often.

When I begin to think about this kind of stuff, the stars, light, the universe, time...I follow my faith.

No scientist has ever remotely implied that science knows everything, but only a fool proclaims science knows nothing as he posts on the internet using the knowledge science has gathered about the behavior of electrons in silicon and other materials saying things which will be stored using the properties of magnets and metals that science knows about in some server rack somewhere.

Yes theories often get added to. That's called 'doing science'. Sometimes hypothesis get disproved, and never grow up to become theories. That's also called doing science. Trying to prove yourself wrong is integral to the process.

Science absolutely does not know everything.
Science does know somethings to a high enough degree of probability to treat them as true.
If that were not true, you would have no computer with which to post your objection or response.

 

[Bionic]

yup... 50% likely.

This makes no sense. It's equally unlikely as it is likely. The point stands.

 

[Grat3fulh3ad]

and 50% unlikely!

right... it might tale a little longer.

However when talking probability, it is not customary to discuss the unlikelihood of something.
You find probability statistics not improbability statistics.

 

[Grat3fulh3ad]

This makes no sense. It's equally unlikely as it is likely. The point stands.

not really.
The language used in the thread title is absolutely correct. There are always multiple ways to say the same thing.
stop being such a nitpicker.
The title stands.


it makes sense. study probability.


Had I said "it is more likely than not" then you'd have a point.

 

[Bionic]

The imminent end of time is a little unsettling but the argument is by no means water tight. Among other things it depends crucially on an important assumption about the laws of physics: that we ought to be able to understand why they work, not just observe that they do work. And that's a philosophical point of view rather than a physical argument.

You're coming off as douchey. It is misleading not nonsensical. Study English. And it's equally as UNLIKELY to happen.

 

[Grat3fulh3ad]

it is irrelevant that it is equally unlikely that it will happen within the earth's life span.
The thread title is still phrased properly. You're coming across as nitpicky.

Study english.

To say it is likely, it not the same as saying it is more likely than not.
It means there is some likelihood that it may occur.

sorry you got confused.
maybe you should retire from grammar policing.

besides you need to be bitching to the guy that wrote that article, it is his title.
http://www.technologyreview.com/blog/arxiv/25807/?ref=rss






wannabe grammer police ftl.

 

[Bionic]

The likelihood is equal to the unlikelihood. 50% means the same thing now as it has always meant and will always mean. Good night.

 

[Grat3fulh3ad]

where have you seen a paper which discusses probability, speak in terms of the unlikelihood of something? things are assigned a likelihood, not an unlikelihood. any statistician would consider 50% probability likely. good night.

 

[jburns]

i enjoyed the article.they think its kinda like a big sneeze, is what i got out of it.