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The Future of Science Revealed! 280

Posted by Roblimo from the not-with-a-bang-but-a-(cold)-whimper dept.
Well, one science journalist's opinion, anyway. Charles Seife writes for Science magazine and is the author of Alpha and Omega: The Search for the Beginning and End of the Universe. These are his answers to your questions, and they're very detailed, to the point where you may want to set aside more than a few minutes of quiet time to read and digest them.
Q1) "Publishing hype" by BobTheLawyer (#6606631)

A1)I'm not embarrassed at all because it's not hype. Scientists now know how the universe will end. Of course, as with all things scientific, there's a big honking asterisk on the word "know," but before I get to that, let me explain why I feel justified in making such an arrogant statement.

We're in the middle of a scientific revolution, in the honest-to-god paradigm-shift sense. This revolution started in 1997 when two groups of astronomers, the High-Z Supernova Search Team and the Supernova Cosmology Project used the bright flashes of a particular type of dying star (a type-Ia supernova) to measure the expansion of the universe at different times in the past. Since then, a whole raft of astronomical observations -- of faint patterns in the afterglow of the big bang, of distributions of galaxies, of the composition of intergalactic clouds of gas, of distortions of light going around massive bodies -- have all forced cosmologists into a remarkable consensus about the composition of the universe and, yes, its fate.

Just to give you a little taste of what the difference in the state of knowledge was like: in 1997, if you asked an astronomer how old the universe is, you'd get an answer somewhere between 12 and 15 billion years. Now, you'll get an answer of 13.7 billion years, plus or minus about 100 million. That's a big jump in precision. Similarly, before 1997, nobody had a clue how the universe would end; now, cosmologists agree on its fate. Some of the details haven't been worked out (what an understatement!), but the gross picture of the ultimate fate of the cosmos seems to be pretty well established for the first time in history. And by the end of the decade, a lot of the details will be fleshed out.

The ongoing revolution isn't just astronomical; it's physical. A decade ago, nobody knew whether neutrinos have mass. (For those who aren't particle physicists, neutrinos are particles that so rarely interact with matter that they can easily pass through the Earth without noticing the big chunk of mass they've passed through. This property makes them exceedingly hard to study.) Now, neutrino physicists are in accord -- and they've concluded that neutrinos, collectively, weigh about as much as all the visible stars and galaxies in the universe combined. High-energy physicists are using an accelerator in Long Island to recreate the condition of the universe a few microseconds after the big bang. By next year, they will formally announce the creation of a new state of matter that existed only in the very, very early universe. (There are alreadystrong hints that they've succeeded.) And another particle accelerator under construction in Geneva is very likely going to discover the particle responsible for exotic dark matter. (More on this shortly.)

All these experiments, all these observations, are pointing in exactly the same direction; they reveal the composition of the universe and its fate. But as with any good scientific revolution, such as relativity or quantum mechanics, it generates more questions than it answers. Scientists now know how the universe will end, but that understanding comes at the cost of a new mystery in physics.

As to the asterisk on the word "know," scientists are acutely aware that their theories are subject to revision. But at the same time, they have good reasons for being confident about their theories -- and they are more confident about some theories than about others. The new cosmological picture that's emerged has a darn high confidence rating; extraordinary claims require extraordinary proof, and the scientific world wouldn't accept the ideas of dark matter, much less dark energy, if there weren't a number of independent lines of evidence that forced scientists to make that conclusion. And while they're not confident about many of the details of the cosmos and the mechanisms that shape it, they are pretty sure that the overall picture is correct. (More on this coming, too.)

Q2) [Almost] Serious question! by Noryungi (#6606694)

and

Q3) Why does the rate of expansion change? by Anonymous Coward (#6606745)

A2,3) The universe will end in... umm... you really want me to give away the ending to my book?

Actually, I reveal the answer in chapter four, because the understanding of the fate of the universe is just the beginning of the current cosmological revolution. So it's not a spoiler to say...

-- drum roll -- the universe will die a heat death, or "Dark & Cold" by your terminology.

In a big bang universe governed by the laws of general relativity, there are two possibilities. (Actually, there are more than two, but all the cases boil down to two real outcomes.) Big crunch or heat death, fire or ice.

The fate of the universe depends on how the universe expands. In general, things that expand cool down and things that are compressed heat up. (This is what causes a propane container to feel so cold after a barbecue -- all the gas that expanded.) After the big bang the universe was extremely hot and was seething with energy. As it expanded, it cooled; free-roaming quarks condensed into protons and neutrons, and wound up as hydrogen, helium, and a handful of other light elements and isotopes. About 400,000 years after the big bang, the universe cooled enough so that the electrons could combine with the nuclei and form neutral atoms. Now, about 14 billion years later, the universe is a pretty cool place.

The expansion of the universe is like a cannonball shot into the air. As the cannonball flies ever higher, the force of gravity tries to drag it back to earth, reducing its upward velocity and slowing it down as it zooms upward. If gravity is very strong, then the cannonball rapidly loses its speed and quickly comes crashing back to the ground. On the other hand, if gravity is very weak, then the cannonball might escape the pull of the earth entirely and zoom away into outer space.

Similarly, the big bang gave the universe an initial cannonshot of expansion. If the mutual gravitational attraction of the objects in the universe is very strong (if there's a lot of matter in the universe) the expansion will slow down, halt, and eventually reverse itself. After the cooling phase of expansion, the universe will begin to swallow itself, getting smaller and smaller each day. This will make it heat up. The skies will get brighter and brighter as galaxies and stars get closer and closer together, and eventually, the universe will become a bath of radiation once more. Electrons will separate from atoms, atoms and then protons and neutrons will shiver into their components, and the universe will collapse in a "big crunch," a reverse big bang. The cosmos will die a death by fire.

On the other hand, if there's not much matter in the universe, then the expansion of the universe will continue forever. The expansion will slow down, but it will never halt and never reverse itself. The universe continues to cool down, and for a long time, space will look pretty much as it does now. Stars will be born and die, and galaxies will age. The night sky would get darker and darker as distant objects get too dim to view, and eventually, as the hydrogen in the universe is consumed, stars and galaxies will begin to wink out. Many billions of years hence, the universe will be a lifeless soup of dim light and dead matter. It will be a death by ice.

In 1997 and 1998, the two supernova teams used the brightness of distant supernovae to measure the rate of expansion at different times in the past. (Because the speed of light is finite, looking into the distance is the same as looking into the past. This causes no end of tense problems when writing a book about cosmology.) What they found was absolutely gobsmacking. Not only was the universe's expansion not slowing down very much -- it was speeding up! The cannonball was zooming into the air faster and faster as if it were propelled by some sort of weird antigravity force. Not only was the cannonball going to escape, it is so OUTTA HERE! This means a death by ice.

Yegads -- an antigravity force. This was a really hard thing for scientists (and probably you) to accept. But there's a number of different lines of evidence that support the idea, and in the book I go through those lines of evidence in great detail. I'll have to settle for a brief summary here. In 2000, a balloon experiment known as Boomerang took very detailed pictures of the ubiquitous afterglow of the big bang, the cosmic microwave background (CMB). This afterglow has hot and cold spots in it, and for years, scientists have been making very, very detailed predictions about the size and distribution of those spots. The results of the Boomerang experiment and the DASI and WMAP experiments matched those predictions incredibly well, giving scientists great confidence in the underlying theory. It also allowed them to figure out the amount of matter and energy in the universe, and 73% of the "stuff" in the cosmos was dark energy, this antigravity force.

There are a number of other lines of evidence, too; the current distribution of galaxies, for example, implies the presence of an antigravity force, and just last month, scientists made a very nice measurement of something known as the late integrated Sachs-Wolfe effect. This effect can't occur unless you have something like dark energy counteracting gravity's pull.

Unfortunately, a fuller exposition requires a lot more writing -- it takes up several chapters in my book. (Shameless plug). But in summary, there's a number of independent observations that all point to the existence of a dark energy. Furthermore, the theories underlying the idea have made very specific predictions that have been verified with incredible precision. It's extraordinary stuff, but no matter how scientists look at it, they're forced by extraordinary evidence to make the same conclusion.

Yes, it's true that scientists don't know the mechanism of dark energy (though they're not entirely at sea) but there's little doubt that the cannonball is zooming into space faster and faster. They don't know precisely why, but the universe is being pushed toward its icy death by an antigravity force. Scientists are watching it happen.

And you don't need to wait billions of years to know the outcome -- you don't need to observe something directly to conclude that it's going to happen. The planet Pluto was discovered in 1930. So why don't people object to the statement that it takes about 250 years to complete an orbit? Just as you don't have to wait until 2180 to confirm the conclusions of Newtonian dynamics, you don't need to witness the end of the universe to be able to figure out its fate or validate the theory that leads you to that prediction.

Q4) Dark Matter by notcreative (#6606772)

A4) You are correct; the nature and location of dark matter are crucial puzzles in modern cosmology, but I think that the answers will be pretty much in hand by the end of the decade.

I've already mentioned results (most notably WMAP) that reveal the amount of "stuff" in the universe, and 73% of it is dark energy. The rest is matter. But the grand total of the matter locked up in visible stars is a mere 0.5% of the stuff in the universe. What is the other 26.5%? That's dark matter, and, in fact, there are two different types.

Scientists have known for decades that most of the matter in the universe is invisible to telescopes. In the 1960s, Vera Rubin measured the motion of stars wheeling around the center of the Andromeda galaxy and concluded that there had to be a lot more matter pulling on those stars than could be seen.

Despite what some contrarians say, dark matter isn't dogma; viable alternatives, like Moti Milgrom's MOND are taken seriously, if not accepted. Unfortunately, all of the alternatives, including MOND, fail in crucial ways. Besides, you can see dark matter, both directly and indirectly. The MACHO and OGLE projects see the twinkle of stars caused by a passing chunk of dark matter, and they can see the distortion of light caused by a huge amount of unseen mass sitting on the fabric of spacetime. (Distant galaxies are stretched into arcs around this gravitational lens.) This is allowing scientists to figure out just where dark matter resides. But at the same time, a number of observations lead scientists to conclude that the minority of the matter (dark or light) in the universe is ordinary, atomic matter -- the stuff of stars, planets, and people. Again, it will take too long to describe all the lines of evidence, but one powerful way of measuring the number of atoms in the universe is to look at the proportion of hydrogen to deuterium, helium, and lithium in primordial gas clouds. In the first three minutes of the universe, atoms were fusing, just as they do in a hydrogen bomb. The universe was a giant pressure cooker, turning protons and neutrons into heavier elements. If there are a lot of atoms, then there is a lot of fusion and a lot of heavy elements made; if there are not very many atoms, then the universe winds up being almost entirely hydrogen. By looking at the ratios of heavy elements to light elements, scientists concluded that atomic matter makes up about 4% of the "stuff" in the universe -- which is precisely what other measurements, like the CMB ones -- imply, too.

So, 27% of the stuff in the universe is matter: 4% "atomic" matter, leaving 23% to be made of "exotic" matter, stuff that's not made of atoms. I've already described some of that exotic matter; neutrinos make up about 0.5% of the stuff in the universe, about the same as the visible matter in the universe. What's the remainder?

That's the big open question, but one that I'd wager will be solved by the end of the decade. There are very good reasons -- particle physics ones, rather than cosmological ones -- for believing that the main constituent of dark matter is a proposed particle known as the LSP. If it is, then the LHC accelerator in Geneva will find it. If not, then the LSP almost certainly doesn't exist and the puzzle will be compounded -- but I think that scientists are extremely optimistic. Again, there's lots more detail in the book about the justification for this.

Q5) variable constants by Cally (#6607000)

A5) The point's well taken, and I'll get to it after a few remarks.

First, you're right in that the supernovae serve much the same purpose as Cepheid variable stars do -- they're both objects of known brightness, or "standard candles," that allow astronomers to make a precise measurement of the distance to a faraway galaxy. However, they are not the same thing. Cepheids are stars that pulsate and the rate of that pulsation reveals its intrinsic brightness. They're what Hubble used to spot the expansion of the universe in the 1920s, but they're relatively dim and impossible to find in very distant galaxies. Type-Ia supernovae are standard candles that are much, much brighter than Cepheids, and so can be seen halfway across the universe. (And as you note, since distant supernovae mean ancient supernovae, they reveal the expansion rate of the universe billions of years ago.)

Second, the time-varying speed of light (or more precisely, the time-varying fine structure constant) is a controversial idea. The scientists that made the observation in question are pretty solid and they're taken seriously. However, my impression is that mainstream thinking is that the results are due to a systematic error. That aside, the effect, even if real, is very small, and it has nothing to do with interpreting the data from standard candles. The interpretation there is quite well established; there's little question that scientists are seeing an expansion of the universe;. Alternative theories, like tired light, fail in countless ways and scientists have even seen the relativistic time dilation caused by the motion of the distant object.

But, yes, it's natural for a layperson to conclude that the concordance cosmological model is looking increasingly kludge-y, and you're naturally led to wonder whether scientists are trying to prop up a failing model with the equivalent of epicycles or aether. I don't think this is the case for a few reasons.

For one thing, the theory isn't really getting added to and made more complex; it's getting subtracted from and being made more simple. This seems counterintuitive, but it comes from the fact that modern big bang theory is really a class of theories, rather than one set-in-stone dictum about the way the universe is. All these theories agree on the basic physics about the manner of the universe's birth, the forces that drive the universe, and the physics behind them; the difference between the theories are the values of a handful of parameters that are not predicted by the theory. These parameters are inputs rather than outputs, and by pinning down the values of these inputs, the acceptable class of theories gets narrower and narrower.

Dark energy is one of these inputs. Although nobody took it seriously before 1998 -- everyone thought that the value of the parameter in question was zero -- it was lurking there nonetheless. It turns out that this parameter is not only non-zero, it's really big, much to everyone's surprise. But this doesn't add complexity to the model, especially since other parameters, such as the "curvature" of the universe as a whole, which many physicists thought would be non-trivial, turn out not to be important after all. (In other words, the universe seems to be slate flat, rather than saddle-shaped or sphere-like.)

So, from a mathematical viewpoint, the model is no more complex than it was in 1997, and is, in fact, significantly leaner. But what about from a physical viewpoint? Dark matter and dark energy seem to fly in the face of Occam. But here, too, the increase in complexity is much less than it appears. Long before this cosmological revolution, astronomers knew that dark matter had to exist; more recently, they've begun to see it. Even without worrying about cosmological questions, astrophysicists had accepted the existence of dark matter. Cosmological measurements like WMAP showed that these astrophysicists were right -- it was an independent confirmation that dark energy exists and that it comes in two forms, something that other astronomers had concluded a while ago.

Dark energy, on the other hand, has more claim to being a "hack" to the theory. It really is something new and unexpected (even though it was always a mathematical possibility, nobody in the physics world suspected it actually existed.) Nevertheless, the groundwork was already there, and modern big bang theory implicitly requires the existence of a form of dark energy in the very early universe. And since the 1930s, scientists knew that even the deepest vacuum is full of energy and can exert pressure (something known as the Casimir effect, which I describe in this book and in my previous book, Zero: The Biography of a Dangerous Idea). Thus, the idea of dark energy wasn't completely alien to physics before 1997, and in some sense, it was a necessary component.

Yes, it's possible that scientists are looking at the cosmos in the wrong way, and somebody will establish a simpler, more elegant theory that takes all these threads and weaves them together. (More on this shortly.) But at the moment, far from having a kludged-up theory, cosmologists have a leaner (if weirder) theory than ever before -- one that makes very precise predictions that are getting verified with stunning accuracy. I think this argues for increased confidence in the theory rather than for increased fear that it's falling apart.

Q6) Universe's container by bios10h (#6606748)

A6) It freaks a lot of people out. There's a lot of philosophical problems with having an infinite universe -- for example, if the universe is truly infinite, and if, as scientists believe, the number of quantum states of a finite volume is finite, then it's hard to escape the conclusion that, some great distance away, there's a bizarro-you on bizarro-earth reading bizarro-Slashdot. On the other hand, there's no positive evidence that I can think of that the universe is truly infinite; it's just the sparest conclusion in a mathematical sense, if not a philosophical sense.

But an infinite universe is not a foregone conclusion. Earlier this year, Max Tegmark at the University of Pennsylvania published an intriguing paper that looked at slight anomalies in the WMAP data that seem to imply that the universe is not only finite, but shaped like a donut. Nobody takes the idea terribly seriously, not even the author, because there are other statistical tests that seem to rule the donut-shaped universe out. But it's the sort of thing that people are looking at very closely.

Whether it's finite or infinite, in a mathematical sense, there's really no need for the universe to be "in" anything -- there are models where our universe is embedded in a higher-dimensional space, but there are models where it isn't. Philosophically, though, I don't see any advantage to embedding the universe in something bigger -- as you say, it just punts the problem forward. (Who, then, will contain the containers?)

It's one of those things that is hard to get comfortable with -- and even when you accept it, it sometimes can cause pangs of uncertainty. Quantum mechanics does this, too... it's just something that's hard to wrap your head around. Take solace in the fact that it's hard for everyone else, too.

Q7) How ultimate is the end of the universe? by Lane.exe (#6606766)

A7) If there were a collapse-type universe, yes, there could be a reboot and a new big bang. (And if Microsoft built the universe, a reboot would be coming sooner rather than later. *duck*)

In fact, the theory behind the cosmic microwave background stemmed from calculations to see whether this was possible. Remember the expansion-cooling/contraction-heating bit I mentioned a while ago? A physicist at Princeton was trying to figure out whether matter would break apart into its constituents in a collapsing universe, so he looked at how the universe heated up as it compressed. He then realized that his calculations worked equally well in reverse -- the young expanding universe was very hot but cooling -- and it had to have an afterglow: the CMB.

There are restrictions on this rebirth argument, though. For one thing, the fact that the universe will expand forever prevents a big crunch in our future, so we're at the end of the line if such a line existed. And in 2001, Alan Guth proved a mathematical theorem that shows that bang/crunch/bang universes can't have an infinite history; they must have started some finite time in the past. (Though there are a few ways around the theorem if you reject a few assumptions.) So yes, it's possible, but there is no reason to believe it actually happened, and there are very good reasons for thinking it won't happen in the future.

Q8) comparable ramifications? by sstory (#6606658)

A8) I'm not going to give the usual B.S. answers about spinoffs (though there are some). And I'm not going to evade the question by saying that genomics hasn't yielded any transformation, because the potential is certainly there. But I will answer this question obliquely.

If I asked you, "Quick! What's the most important scientific achievement of the 20th century?" how would you respond?

You would probably answer relativity or quantum mechanics, or perhaps the Apollo landings. Probably some would say the atom bomb. I suspect that only a handful of people would mention the computer, and even fewer people would say penicillin. (Am I right?)

Science has two faces -- it can transform society (for better or worse), and it can advance human knowledge. The two are not inextricably bound, though they often come together.

Relativity was a profound shift in our understanding of the way the universe works, but you have to look pretty hard to see a direct effect on our lives. Conversely, penicillin wasn't a central advance in understanding biological systems, but it affected all of us -- I suspect many people here on Slashdot wouldn't be alive today without penicillin and its descendants.

For me, though, relativity is a greater scientific triumph than penicillin -- even though penicillin is probably much more important to us. It altered our view of the universe and gave us a greater understanding of the fundamental laws of the universe -- it was a philosophical advance as much as it was a technical one. That's why we seem to admire Einstein more than Fleming and Newton more than Jenner.

The present cosmological revolution won't change our lives dramatically; heck, a good spam filter would probably have more direct effect on our quality of life. But at the same time, it will finally answer some of the most ancient questions of humanity -- where did the universe come from and how will it end -- and when it ends, we will have a firm grasp of the answer of the latter if not the former. It will be a towering intellectual achievement, and I think that is what will set it apart from even the human genome project.

Q9) What is the next paradigm shift? by geeber (#6606890)

A9) I disagree with the idea that there's no paradigm shifts left -- indeed, I think we're in the middle of one now. I think that it will be associated with one in the Standard Model of particle physics that will begin before the end of the decade.

It's hard to say where future paradigm shifts lie, but there are lots and lots of outstanding questions in science, some of which are incredibly basic, yet totally out of scientists' reach. For example, neurologists have a very good idea about how individual neurons work -- how they connect and communicate. But when it comes to explaining how a large sloppy hunk of neurons becomes a conscious entity, they're completely at sea. I don't think there's even a good definition of consciousness, which is crucial if you're going to study it seriously. Even more basic -- scientists are struggling to define what life is. There's a heck of a lot more work to do, and plenty of room for paradigm shifts.

Speaking of paradigm shifts, I'd like to take a bit of issue with the term (which I've used myself a number of times in the responses to these questions.)

For those who don't know, the idea of a "paradigm shift" comes from Thomas Kuhn's Structure of Scientific Revolutions, a seminal work in history of science. While I think that Kuhn's idea of a paradigm shift has a lot of merit -- models and philosophies do change suddenly and dramatically in the face of mounting conflicting evidence and despite resistance -- I think the term itself is misleading. It implies the complete abandonment of one idea and acceptance of a replacement.

In my view, this is not the way modern science works -- I think that science is cumulative. Each model extends and corrects the previous one, and while there might be a dramatic shift philosophically, there is almost never a dramatic shift physically. Relativity, for example, made a profound change in the way we think about time and space and gravity, yet the functional difference between Newton and Einstein is pretty small. All these complicated tensor equations are approximately equal to Newton's laws in the vast, vast majority of cases -- it's only under conditions of extreme gravity, extreme speed, extreme energy, or extreme time that relativistic predictions diverge from Newton's. Similarly with quantum mechanics.

While I think that relativity and quantum mechanics are paradigm shifts, they're not rejections of the Newtonian picture as much as they are extensions. The paradigm shift can be huge philosophically, but its effects tend to be small in magnitude. And with these small corrections, scientists extend the applicability of their model of the universe -- they can explain the orbit of Mercury or the photoelectric effect -- and in the cases where Newton's laws were strong, these models boil down to Newton's laws.

If I remember my Kuhn correctly, he explicitly rejected the idea of cumulative science; he really saw each model getting completely replaced by its successor, rather than as an extension -- and this leads, at least in my view, to the excesses of postmodernism.

I think that this issue goes to the heart of the questions about how scientists can be sure about the end of the universe if their models can be replaced at any time. To that I'd argue that, yes, all models are provisional, but even with "paradigm shifts" models are usually extended rather than replaced. The central findings of the previous model still hold with good accuracy in most cases, even if the philosophical underpinnings are badly shaken. Maybe scientists are missing some crucial understanding that will simplify the way we look at the universe -- and scientists are seriously pondering alternate models to things as widely accepted as the inflationary big bang -- but even if such a shift occurs, it probably won't invalidate today's discoveries.

Q10) What will it mean? by boatboy (#6607285)

A10) One thing's certain. If I knew the answers, I'd be even more insufferable than I am now.

Seriously, I'm not sure that knowing the answers would have a profound moral and sociological effect. While I think that asking and answering big questions is a hallmark of a prospering society, a society doesn't necessarily draw strength or stability from its intellectual curiosity. (For example, Athenian democracy lasted only about 80 years if I remember right.) Even the most profound philosophical ideas can wind up having little real effect on the everyday functioning of a civilization -- for example, I think that Godel's incompleteness theorem hasn't changed society in the slightest.

As for the next big question, I think there are some in biology: what is life? What is consciousness? How did life arise? Are we alone in the universe? In physics, I think there are profound questions yet to be answered in a realm that I'd describe as "information theory" in the broadest sense -- what's really going on in a black hole? What makes quantum mechanics so weird? And I think that answering the question about the true nature of dark energy will probably have to await a future cosmological revolution. But one of the wonderful things about science is that you don't really know what big questions are within your grasp until you begin to grasp them. We'll know the next revolution when it appears.

Editor's note: Due to long answer lengths, we linked to the questions instead of running them directly here in order to keep this page from getting too large. This was an experiment. If you have comments or questions about Slashdot interview formatting, please email Roblimo.

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The Future of Science Revealed! More

The Future of Science Revealed!

Comments Filter:

  • The real question: (Score:5, Funny)

    by Eric(b0mb)Dennis ( 629047 ) * on Friday August 08, 2003 @02:13PM (#6647837)
    The year is 2125, a mars outpost is posting their first research on the inter-net-net using the tachyon stream to transmit their data.

    A well known website known as Slashdot.org posts a link to the research papers, all of the sudden, the entire universe collapses because the tachyon stream was overloaded.

    That is the end of the universe, all of humanity blinked out of existence.

    Slashdot.org, a useful forum of information, or the end of the world waiting to happen? You decide.

  • Obligatory Simpsons Quote (Score:4, Funny)

    by magsymp ( 562489 ) on Friday August 08, 2003 @02:18PM (#6647900)
    donut-shaped universe mmmmmmmmm.... donut.

  • Questions? (Score:4, Insightful)

    by efflux ( 587195 ) on Friday August 08, 2003 @02:23PM (#6647953)
    What happened to the questions? These links to the actual questions are a pain to read. More than subject headings would have been nice

  • A7 (Score:5, Funny)

    by roman_mir ( 125474 ) on Friday August 08, 2003 @02:23PM (#6647957) Homepage Journal
    If there were a collapse-type universe, yes, there could be a reboot and a new big bang. (And if Microsoft built the universe, a reboot would be coming sooner rather than later. *duck*) - this is /. You don't have to *duck*!

  • if we find ... (Score:5, Funny)

    by i.r.id10t ( 595143 ) on Friday August 08, 2003 @02:24PM (#6647976)
    If we find the "end of the universe", will there be a resturant, perhaps with a evening show?

  • Excellent interview (Score:5, Insightful)

    by Timmeh ( 555676 ) on Friday August 08, 2003 @02:26PM (#6648001)
    This is easily on of the best interviews I've seen on slashdot in a long time. Kudos to Charles Seife for writing extensively instead of sort of brushing us off with the brusque answers usually found in the interview section. It feels like if the person being interviewed isn't into the whole 'technology'/slashdot/nerd thing they look down on us and humor us with their answers instead of writing interesting replies.

    • Re:Excellent interview (Score:4, Funny)

      by Mostly Harmless ( 48610 ) <mike_pete@nospAM.yahoo.com> on Friday August 08, 2003 @02:38PM (#6648125) Homepage
      I agree, this interview is outstanding. I like this the best, something that you don't hear too often:

      One thing's certain. If I knew the answers, I'd be even more insufferable than I am now.

      Not only does he acknowledge that he wrote a bunch, but he knows that he doesn't know everything. That's refreshing around here. He admits that things change, and what he says isn't the be-all-end-all of ideas. But, perhaps, the most refreshing thing in the interview is that he didn't answer a single question with "42." Now that's something new!

      • I agree, this interview is outstanding.

        Now if a regular user like I was going to write a huge interview like that, I would be sorely disappointed if the review were rejected. What's the motivation for me to go out and try to produce something so lengthy and in-depth?

        Not only does he acknowledge that he wrote a bunch, but he knows that he doesn't know everything.

        I like the part where he mentioned the huge asterisk when scientists say they "know" something. It always bothers me when people say scient
    • Followups?

      Ferinstance: I've read for some time about the idea that all of space is filled with a super-duper tiny froth of particle-anitparticle pairs spontaneously forming and mutually annihilating. Couldn't all these particles, even though they exist for short times, exert gravitational (or other) force and account for some missing mass? Maybe even the "dark energy"?

    • This is easily on of the best interviews I've seen on slashdot in a long time.

      Yeah, so true. And all thanks to me.

      Why? - you may ask. Well. Because every time I'm on a brink to delete /. from my bookmarks, history and CTRL-H keybind (yeah, I'm pathetic), they manage to pull stuff like this.

      Great many thanks to Charles for this!

  • REALITY.SYS (Score:3, Funny)

    by kleine18 ( 675867 ) on Friday August 08, 2003 @02:29PM (#6648028)
    REALITY.SYS corrupted: Re-boot universe? (Y/N).

  • Bizaro Slashdot (Score:4, Funny)

    by mike_mgo ( 589966 ) on Friday August 08, 2003 @02:30PM (#6648041)
    Considering the comments I read in most of the articles I thought I was on bizaro slashdot.

  • Huh? (Score:2, Flamebait)

    by Austerity Empowers ( 669817 )
    Why is Roblimo interviewing a journalist at a science magazine? Why not interview the scientists themselves?

    I believe this guy is better than your average journalist at summarizing key ideas, but this is a website for nerds. Give us the real deal or give us more SCO stories.

  • Dark Energy (Score:5, Interesting)

    by cybercuzco ( 100904 ) on Friday August 08, 2003 @02:38PM (#6648127) Homepage Journal
    Heres a question: Since theres so much more dark energy than matter, would it be possible that some future descendants of humans could tap this energy to slow or stop the expansion rate of the universe, or even recreate galaxies using the energy? This might be a good sci-fi novel topic ;-)

    • Re:Dark Energy (Score:5, Interesting)

      by EvilTwinSkippy ( 112490 ) <yoda AT etoyoc DOT com> on Friday August 08, 2003 @04:45PM (#6649635) Homepage Journal
      You are assuming that the Universe we are experiencing is not, in fact, a reflection of a deeper structure. Our perception of that structure at present is expanding, but at some point in time a controlling factor could take affect and reign everything back in.

      I like to think of the Universe as an organism. It has a definite beginning event. The end, is not so clean cut.

      Let's imagine our Universe is in fact a human being.

      Now imaging you are a microcivilization who came into experience when the human was 4 years old. An entire civilization would wink in and out of existance by the time the Universe's heart beat once. If they tried to observe all of the molecules in the body, they would see a rapidly expanding organism, that seems to have at one time occupied a single point in space.

      Despite the illusion, around puberty the Universe would stop growing.

      • Let's imagine our Universe is in fact a human being.

        Now imaging you are a microcivilization who came into experience when the human was 4 years old. An entire civilization would wink in and out of existance by the time the Universe's heart beat once. If they tried to observe all of the molecules in the body, they would see a rapidly expanding organism, that seems to have at one time occupied a single point in space.

        Despite the illusion, around puberty the Universe would stop growing.

        That's an interestin
        • Are you saying that the universe won't eventually die, or that its fate cannot be predicted by what we can see of the past?

          Mostly that past performance is no predictor of future returns. We haven't even scratched the surface of what's out there. It's a little premature to say ANYTHING about the Universe with authority, considering that we still haven't solved a few basic problems of celestial mechanics.

          For instance, the reports position of the Pioneer spacecraft is off from where all of our theories abo

    • Re:Dark Energy (Score:5, Interesting)

      by renard ( 94190 ) on Friday August 08, 2003 @05:49PM (#6650370)
      Since theres so much more dark energy than matter, would it be possible that some future descendants of humans could tap this energy...

      First answer: No. Dark energy is a property of the vacuum itself - being able to tap into it would be like extracting energy from a uniform, infinite heat bath (the vacuum), or from the zero-point energy of an atom's ground state, and would enable construction of perpetual motion machines and other impossibilities. That is, extraction of useful work from the "dark energy" is ruled out by basic thermodynamics (or, if you prefer, basic quantum - the same principles apply). However...

      Second answer: Maybe. In general it is true that the universe and the systems in it tend naturally towards their ground states (increasing entropy). However, it is also true that thermodynamic fluctuations happen, every now and then, and the lifetime of these "defects" can be quite long - think, for example, of the conjectured cosmic strings. Now that we know the Dark Energy exists, we can guess that it might be possible - far, far in the future, when we are an intergalactic species - to find some defects in the system. We could then set up some apparatus, and extract energy from these defects as we watch (or encourage) their "decay" to the true ground state.

      Stopping the expansion of the universe itself, however, will even then be well out of reach. Our best long-long-term bet, if you ask me, is to create our own new universe and go live there, once this one gets old...

      -renard

  • The Last Question (Score:2, Informative)

    by I8TheWorm ( 645702 )
    Isaac Asimov already figured it out...

    The Last Question [inf.elte.hu]

  • Please correct (Score:3, Informative)

    by Viking Coder ( 102287 ) on Friday August 08, 2003 @02:40PM (#6648156)
    Editors, please correct the missing quote in the URL right after the first occurance of the phrase "MACHO".

  • Stephen Hawking says: (Score:3, Funny)

    by spun ( 1352 ) <loverevolutionary@@@yahoo...com> on Friday August 08, 2003 @02:41PM (#6648172) Journal
    Your theory of a donut shaped universe is intriguing, Homer. I may have to steal it.

  • Good, but old hat (Score:4, Funny)

    by eclectic4 ( 665330 ) on Friday August 08, 2003 @02:45PM (#6648214)
    Sorry, it's just that this info is old hat to anyone who keeps up on astro-phys stuff. In fact, SciChannel has had some very good, well produced shows about these very things for quite some time now.

    I don't mean to be a bubble burster, it's just that this stuff was "revealed" quite a bit ago.

  • I wonder... (Score:2, Interesting)

    by SifuDave54 ( 662394 )
    is it possible that there are life forms consisting of dark matter that are just as oblivious to our existence as we are to them?

    I'm not talking about exotic forms of conciousness created sporadically from energy or those sorts of things. I'm talking about life as we know it.

    Or does current dark matter theory rule out the idea of life as we know it existing in dark matter?

  • The Pluto Analogy (Score:4, Insightful)

    by mike_mgo ( 589966 ) on Friday August 08, 2003 @02:47PM (#6648234)
    I think this analogy is flawed.

    The reason people accept that the Newtonian prediction that Pluto will take 250 years to revolve around the sun is that there are plenty of other planetary bodies that are observed to follow those rules. But in the case of the ultimate fate of the universe we obviously have no other reference to compare this theory to. I realize that there probably are verifiable predictions the theories do make (birth and death of stars/galaxies) but the ultimate result can never be checked.

    I'm not trying to imply that this theory is wrong, just that there are always likely to be questions raised since it is ultimately unverifiable. Obviously bits and pieces (probably even the majority of it) can be confirmed, but we'll never be able to say, "This theory acurately depicted the ultimate death of Universe Alpha over there and that's going to be the same fate as our universe."

    • And let's not forget the really big assumption of science:

      "That which happened in the past will repeat itself in the future." How do we know this? Because it has always been true in the past.

      • ...the really big assumption of science...

        As opposed to, say, the really big assumption of your going to sleep each night and expecting to wake up in approximately the same body, and approximately the same bed, with approximately the same house around you, and approximately the same sun up overhead?

        How do we know this? Because it has always been true in the past.

        1. It's not knowledge; it's a prediction. And as far as that goes - so far, so good.
        2. If you've got a better idea, I'm all ears.

        -renard

      • We don't know it, we assume that under the same situation, things will react the same way. We go with this until we're proven wrong/find out something new we didn't know before.

        If you don't want to accept this premise then there's really no reason to believe that in 2 seconds everything you know will cease to exist or any other of the infinite possibilities out there.
    • Sounds like an attempt to define something which could quite possibly be infinite as being finite

      Thats not to say it isn't worthwhile research; the Universe may very well be of finite existance, It just means that it is bloody difficult research.
    • You may want to pick up the author's actual book [barnesandnoble.com]. In addition to predicting the fate of the universe, the so-called "Concordance Model" of cosmology makes a number of other, eminently testable, predictions.

      One of these is the presence of dark matter - weakly-interacting subatomic particles that even now are (most probably) streaming through your body at the rate of millions per second. We have the technology, now, to search for these, and if we find them (give it a few years) - score another one for t

  • Best interview for a long time (Score:5, Insightful)

    by panurge ( 573432 ) on Friday August 08, 2003 @02:47PM (#6648241)
    This is one of the most sensible, hype-free essays - because it is, virtually, an essay - about cosmology. Too many journalists go apeshit over ideas like infinite universes and present them as if they were completely mainstream cosmology. This seems to be a very balanced account. (And the point about Thomas Kuhn is very well made. I had to stop and think about it, then I found I was in complete agreement.)

    We need competent journalists and technical writers to explain cutting edge science to us just as, though we hate to admit it, we need competent marketing and sales people to sell software.

  • What's the rush? (Score:3, Interesting)

    by Euphonious Coward ( 189818 ) on Friday August 08, 2003 @02:57PM (#6648336)
    So, everybody agrees that the universe has billions of years left on its meter.

    So, what's with the rush to pin it down now? The experiments being run now would be thousands of times cheaper if we waited thirty years, or a century. Why not run them when they're cheap? Maybe after a decade we'll realize we don't need them at all, and that some other experiments would be more useful.

    Furthermore, why do we need a thousand cosmologists, or a hundred? Seems like a dozen should be enough. Sure, it would be less fun for the rest to spend their time working out fluid flows around funny wing shapes, or whatever physicists do nowadays to try to make themselves useful. Their fun is their business.

    This isn't a question about the usefulness of basic research, but about timing. Lots of immediately meaningful basic research is going undone because of the huge budgets of physicists in a hurry. Lots of the neglected research might have equally profound effects on both our understanding of the universe and on future industries. So the question is, again, what's the damned hurry about cosmology?

    A side question is, why should a cosmologist care whether the idea of a truly infinite universe makes anybody uncomfortable? Anybody who wants comfort can believe we live on the back of a big turtle, and sleep soundly.

    • Well, the universe may have a few tens of billions of years left but WE don't. Not even close.

      There is one postulate that "we" have somewhat less than a few 10s of millions of years - long before the sun expands into a red giant and consumes earth. The geochemical cycle that is REQUIRED to keep water on the surface will not work more than a few more million years. The oceans will be lost into the earth and water locked up in rocks. The surface a dead, dry husk. Long before it gets to this stage, we w

      • It gets even better...

        We, as a race of people, may have a few million years left. As Americans, we may have only few hundred left. As individuals only a few years left.

        Kind of makes a possibly changing
        "fine structure constant" irrelevant.

        Got to go... "All my Children" is coming on.

        --ken
      • No species lives more than a few thousand years and this must likely include modern humans. Though the dinosaurs ruled the earth for many 10s of millions of years, no single species of dinosaur lasted anywhere near that long. Every single one of them died out and was replaced with something else.

        This is absolutely untrue. While many species do just die out, many evolve into something else. There is no time limit on species. Any species will continue to thrive, or at least get by, until environmental fo

    • I don't necessarily think that there's a "rush," per se. It's just that it's a curiously interesting subject and that a lot of people are interested in it.

      Scientists are most happy when we (yes, we) are able to do the research that interests us. Is it really fair to dictate what scientists have to research (outside of subjects that have deeper moral implications)? Where would we be if Einstein was told that he had to study the causes of friction or something like that, instead of letting him explore hig
  • Okay, so there's this Big Bang, right?

    Well, what in the hell stopped all of the matter from forming a black hole and falling in? It was certainly dense enough! WELL beyond the Chandrasekhar limit. (By about, oh, 10^122, right?)

    I've read that you can think of the entire universe as existing inside of a black hole - that kind of explains the "shape" of the universe, and why we can't see "outside" - but black holes leak radiation! (Hawking Radiation.) Where the heck would the UNIVERSE leak radiation to?
    • As I understand it, current big bang theory does say "a really dense ball of matter exploded." If that was the case, then your argument about the Chandra limit would make (some) sense.

      However (someone correct me if I'm wrong), currently the big bang theory is closer to "the three dimensions we live in suddenly became much larger." Think of it this way: Say you have a few small magnets. When you place them close together they will all collect in one big mass. This is similar to what matter will do un
      • Oops! That first line is supposed to say "current big bang theory doesn't say".
      • Okay, so I'll pose my question another way, why did "space" itself expand?

        And why did that expansion, in essence, make the universe so that it WASN'T curved into a singularity?

        In other words, my question really is the big unanswerable one, "Where did all of the energy and mass in the universe come from?" :)

        Thanks for your explanation, though... I recently saw Anthony Lasenby talk about the shape of the universe in a fascinating talk, and it was fun to think about. As with all great persuits, his talk l
  • That's the big open question, but one that I'd wager will be solved by the end of the decade.


    All that remains to be done in physics is the working out of a few physical constants, kids, go study something else with a better long-term outlook.
  • I actually accepted the idea years ago that the cosmos ( as we know it ) will expand into the cold void.

    But I'm wondering.... Will matter speeding away from our big bang some day combine with matter from a totally different bigbang.

    Or even better! What if we could jump off this cosmos and join another one!

  • cool (Score:3, Funny)

    by kryzx ( 178628 ) * on Friday August 08, 2003 @03:27PM (#6648735) Homepage Journal
    I'm just glad to hear that "the universe is a pretty cool place."

    If I found out I'd spent my whole life somewhere uncool that would just be depressing.

  • I started reading this as my CD player started the soundtrack to Men-In-Black. It was weird reading about all the space this and telescope that and having the theme music going.

    I ought to patent reading AND listening to music at the same time. Slashdot having theme music? It would be funny to put a recommendation to play while reading a story..
  • Actually, I think he's wrong about the universe dying in a cold universe. The expansion of the universe is accelerating, so as this continues the visible edge of the universe will come closer and closer over time (it's currently about 13 billion light years away, but it's approaching us). Eventually the visible edge will be closer than molecules- at that point all the molecules in the universe fall apart since the electromagnetism will no longer hold them together. Soon after, it will be smaller than nuclei
  • So will SCO/Caldera die a heat death or an ice death?
  • C'mon now. You'll be lucky if 99% of the Slashdot community reads the COMMENTS at +4, let alone the entire interview. Look who you're talking to here!
  • If the universe is going to die, why bother studying it at all? Just when I get it figured out it will be a bit too late.
    I think I will go back to poetry or something..

    --ken
  • I'm so glad we've discovered how the universe will end. WHEW! JAV

  • This cold dead universe assumes that there will be no intelligent intervention. I am not talking about a mythical 'god' at all but more about advanced civilizations. Even humans will be a few tens of billions of years old by this time. Perhaps we or some other race decide a cold dead universe isn't a very happy place and initiate a universal reboot. Or they could be just redecorating ;)

    All of this, of course, assumes that we are still around (very doubtfull) and that there are alians in the universe (u
  • Great interview, but come on... 2-3 word "question summaries" before the answers? WTF? Is Slashdot trying to save electronic trees/hard drive space by not having the full question before the answer? Whose brilliant idea was this? I have an extra 100 meg hard drive lyin' around here that I'd be glad to donate to slashdot if storage is getting so tight that we need "question summaries."

  • Do we have concensus? (Score:2, Informative)

    by khallow ( 566160 )
    We're in the middle of a scientific revolution, in the honest-to-god paradigm-shift sense. This revolution started in 1997 when two groups of astronomers, the High-Z Supernova Search Team and the Supernova Cosmology Project used the bright flashes of a particular type of dying star (a type-Ia supernova) to measure the expansion of the universe at different times in the past. Since then, a whole raft of astronomical observations -- of faint patterns in the afterglow of the big bang, of distributions of galax

  • Wormholes? (Score:2, Interesting)

    by kurtkilgor ( 99389 )
    The way wormholes are supposed to work is that they provide a shortcut through (n>3)-dimensional space around a bend in 3-space. But if the universe is flat, does that mean that wormholes would be useless?
  • It would seem to me that a big-bang that comes out of nowhere would be the ultimate violaion of the conservation of energy principle? If not, then what the heck could have been going on before the big-bang?
  • Yup, it the coolest place to be...

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