A three-dimensional map of the Universe

July 28, 2020 • 1:45 pm

Well, I can’t say I fully understand what’s being shown here, except that it depicts the detectable galaxies in the Universe (some not seen because the Milky Way hides them).  Cosmos has an explanation that I put below the video. If you’re an astronomy buff, you’ll probably understand this, and I’m hoping the cosmology mavens in the crowd will explain in the comments what we’re seeing.

Here’s one video, and another is below:

An explanation from Cosmos:

Astrophysicists have created the largest and most complete 3D map of the Universe.

It includes measurements of more than two million galaxies and quasars covering 11 billion years of cosmic time and involved 20 years of watching the skies and subsequent analysis by an international collaboration of more than a hundred researchers.

It is based on the latest observations of the Sloan Digital Sky Survey (SDSS), titled the extended Baryon Oscillation Spectroscopic Survey (eBOSS). The results and data have been released in more than 20 scientific papers running to 500+ pages.

Prior to eBOSS, scientists only knew where objects such as galaxies and quasars were as viewed from Earth. The new survey provides the distance to each object, allowing them to build a 3D model.

And that adds significantly to our understanding of the expansion of the Universe.

“We know both the ancient history of the Universe and its recent expansion history fairly well, but there’s a troublesome gap in the middle 11 billion years,” says Kyle Dawson, from the University of Utah, US.

“For five years, we have worked to fill in that gap, and we are using that information to provide some of the most substantial advances in cosmology in the last decade.”

The map has been published as a still image and as a 3D animation (below). A close look at the image reveals the filaments and voids that define the structure in the Universe, the researchers say, starting from when it was only about 300,000 years old.

h/t: Barry

Star “outburst”

April 26, 2020 • 1:15 pm

I originally gave this timelapse series the title “star explosion,” but in fact it’s not clear what the deuce is going on here. What is clear is that it’s something spectacular.  The YouTube notes describe what we’re seeing and how the montage was made:

The unusual variable star V838 Monocerotis (V838 Mon) continues to puzzle astronomers. This previously inconspicuous star underwent an outburst early in 2002, during which it temporarily increased in brightness to become 600,000 times more luminous than our Sun. Light from this sudden eruption is illuminating the interstellar dust surrounding the star, producing the most spectacular “light echo” in the history of astronomy.

As light from the eruption propagates outward into the dust, it is scattered by the dust and travels to the Earth. The scattered light has travelled an extra distance in comparison to light that reaches Earth directly from the stellar outburst. Such a light echo is the optical analogue of the sound echo produced when an Alpine yodel is reflected from the surrounding mountainsides.

The NASA/ESA Hubble Space Telescope has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique “thin-section” through the interstellar dust around the star. This video morphs images of the light echo from the Hubble taken at multiple times between 2002 and 2006. The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars.

Anyway, the “event”, covering four years compressed into 49 seconds, is something to see:

But what is it?  Gizmodo gives several possibilities, which also appear in Wikipedia, but Gizmodo leaves out #6: a “common envelope event.

  • An atypical nova outbursts (this is very unlikely.)
  • A thermal pulse of a dying star (the new pulse illuminates the layers of star material previously ejected its previous outbursts.)
  • A thermonuclear event within a massive supergiant (in which the helium in one of the layers of the massive star ignites and starts a fusion process.)
  • A mergeburst (the burst caused by the merge of two main sequence stars.)
  • A planetary capture event (in which the star has swallowed one of its giant gas planets.)

If the last possibility is true, this star got the worst case of gas in the Universe, belching big time.  Actually, I have no idea what’s going on here, and even speculating is way about my pay grade. Readers with some astronomical/cosmological knowledge may wish to speculate.

New evidence for the multiverse—and its implications

December 10, 2017 • 9:00 am

As skeptical as I am, I think the contemplation of the multiverse is an excellent opportunity to reflect on the nature of science and on the ultimate nature of existence: why we are here…. In looking at this concept, we need an open mind, though not too open. It is a delicate path to tread. Parallel universes may or may not exist; the case is unproved. We are going to have to live with that uncertainty. Nothing is wrong with scientifically based philosophical speculation, which is what multiverse proposals are. But we should name it for what it is.

— George Ellis, Scientific American, Does the Multiverse Really Exist?

Well, Ellis’s uncertainty may not be permanent. This short film, on the “skydivephil” playlist, presents what they say is evidence for a multiverse. It was sent to me by reader Phil, who I believe is the eponymous creator .

A multiverse is a collection of all multiple, parallel universes; and in the set taken together, a whole panoply of different things happen: many alternative outcomes are instantiated somewhere. The idea of a multiverse first came from Erwin Schrödinger, and for a long time physicists thought that a multiverse was possible but impossible to test, as there was no way we could detect the presence of universes other than ours. The Wikipedia link two sentences prior gives a good summary, as does the video at the bottom.

Now, according to this video, we’ve gotten some evidence for the multiverse, though our Official Website Physicist™ notes (see below) that the new evidence isn’t terribly decisive. The evidence adduced is cosmic inflation, but not just that: eternal cosmic inflation, in which space grows forever. One of the implications of eternal inflation is, according to some (but not all) physicists, the multiverse.

The Physics Man who presents the results below is George Efstathiou, a British physicist at Cambridge.

When I saw this, realizing that it was above my pay grade, I wrote to Sean Carroll, our Official Website Physicist™, asking him this:

Does eternal inflation really constitute evidence for a multiverse? I know you favor multiverses, but I want to know how strong the evidence is. If you want to give me a quote to post, I’d be delighted to do that, but the most important thing is that I understand what this is about.
Sean responded, and I quote him with permission:
Of course it depends on what you mean by “evidence.” In a Bayesian sense, yes: there is experimental evidence that favors inflation (e.g., in temperature fluctuations in the cosmic microwave background), and theory predicts that most inflationary models lead to eternal inflation and a multiverse, so in that sense there is evidence for a multiverse. But not in a direct, empirical sense, of course: everything we see in the observable universe is also completely compatible with ours being the only universe. And even the indirect evidence is quite weak; we don’t know for sure whether inflation happened, nor if it really does create a multiverse. So one’s credences for or against the multiverse shouldn’t be very close to 0% or 100%, they should be somewhere in between.
 The YouTube notes present a similar caveat:
A note of caution. In our opinion inflation is the dominant paradigm for early universe cosmology and most experts in inflationary cosmology seem to agree it leads to a multiverse. Does the mounting evidence for inflation then mean we should accept the multiverse? Well, inflation has passed every test to date but there is still one last hurdle and it may fail at this last test. It’s also possible that we haven’t understood inflation correctly. We need to wait and see if more data can give us a firmer picture of these fascinating questions. Whilst the evidence for inflation and the multiverse then may not be strong enough to call them facts, the statement that there is no evidence at all for these concepts looks dubious.
 Finally, here’s a list proponents and skeptics from Wikipedia, and there are Big Names on both sides:

Proponents of one or more of the multiverse hypotheses include Stephen Hawking, Brian Greene, Max Tegmark, Alan Guth, Andrei Linde, Michio Kaku, David Deutsch, Leonard Susskind, Alexander Vilenkin, Yasunori Nomura, Raj Pathria, Laura Mersini-Houghton, Neil deGrasse Tyson, and Sean Carroll.

Scientists who are generally skeptical of the multiverse hypothesis include: Steven Weinberg, David Gross, Paul Steinhardt, Neil Turok, Viatcheslav Mukhanov, Michael S. Turner, Roger Penrose, George Ellis, Joe Silk, Carlo Rovelli, Adam Frank, Marcelo Gleiser, Jim Baggott, and Paul Davies.

Now the multiverse has lots of implications for our views of physics, philosophy, and biology. Depending on how you conceive of a multiverse (and there are apparently several ways it could be), the anthropic principle—that the laws of physics seem “fine tuned” for our existence—is simply a result of different universes having different laws of physics, and the one with the “right” laws is the one that is ours, the one that allowed life to evolve. This, of course, blows the “fine-tuning” argument, and its supposed use as evidence for God, out the window. There are, of course, other implications for stuff like quantum entanglement, Schrödinger’s Cat, and other physical puzzles: many different outcomes would be realized in one universe or another. The cat would be dead in some universes, but alive in others.

Further, it means that the evolution of humans was inevitable somewhere. In one of those universes that permitted the evolution of life, it was inevitable that a thinking hominin would evolve. That, too, is evidence against theistic arguments—made famous by Simon Conway Morris—that the evolution of humans, which is taken as inevitable, is evidence for our position as God’s special creatures.

Finally, it may (and I’m not sure about this) constitute evidence for “you can choose” free will: that all possible decisions that could be the outcome of the laws of physics in our brain would be instantiated in some universe. [Rethinking this, I don’t think this buttresses “you can choose otherwise” free will unless it reflects quantum phenomena in the brain, which I don’t think is the case.]

Now I’m just speculating here, and these may not follow from any conception of the multiverse, but from what I’ve heard of the “many worlds” hypothesis, these things are possible.

If you want to watch the entire one-hour video from which the above is an excerpt, I’ve put it below.

Does the nature of the Universe show that there’s no God?

November 4, 2017 • 12:15 pm

That, at least, is the contention of Emily Thomas, an assistant professor of philosophy at Durham University, in an essay at RealClear Science (“Does the size of the universe prove God doesn’t exist?“) This point has been made by many people before, including, as I recall, Carl Sagan and Richard Dawkins: the Universe is unbelievably large and all those extra galaxies and planets would seem to be superfluous if God’s real concern was Earth. After all, the Bible refers to this planet, not others, and so what’s going on with all those other planets, even if they do harbor life?

The good bits in Thomas’s essay are simply the facts she gives (these are quotes from her piece):

  • Scientists estimate that the observable universe, the part of it we can see, is around 93 billion light years across. The whole universe is at least 250 times as large as the observable universe.
  • Our own planet is 150m kilometres away from the sun. Earth’s nearest stars, the Alpha Centauri system, are four light years away (that’s around 40 trillion kilometres). Our galaxy, the Milky Way, contains anywhere from 100 to 400 billion stars. The observable universe contains around 300 sextillion stars. 

The last fact is for just the observable universe. 300 sextillion is 300,000,000,000,000,000,000,000 stars, and multiply that by at least 250 (or more, if the 250 is a linear dimension and not volume). That’s HUGE–even bigger than William Howard Taft! Thomas quotes Douglas Adams here as saying the Universe is “big really, really big”, but as I’m reading The Hitchhiker’s Guide to the Galaxy, I’ll give the full and accurate quote:

Space is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist, but that’s just peanuts to space.

The Universe is also old: about 13.7 billion years. Why did God wait so long to create Earth, and then wait another 4.5 billion years—until about 4000 years ago—to reveal himself to us?

As Thomas notes, this evidence—the size and age of the Universe—does not comport with a God who’s deeply concerned with what happens on Earth: the superfluity of stars and of time does not comport. As Thomas argues:

Over the last few decades, a new way of arguing for atheism has emerged. Philosophers of religion such as Michael Martin and Nicholas Everitt have asked us to consider the kind of universe we would expect the Christian God to have created, and compare it with the universe we actually live in. They argue there is a mismatch. Everitt focuses on how big the universe is, and argues this gives us reason to believe the God of classical Christianity doesn’t exist.

To explain why, we need a little theology. Traditionally, the Christian God is held to be deeply concerned with human beings. Genesis (1:27) states: “God created mankind in his own image.” Psalms (8:1-5) says: “O Lord … What is man that You take thought of him … Yet You have made him a little lower than God, And You crown him with glory and majesty!” And, of course, John (3:16) explains God gave humans his son out of love for us.

These texts show that God is human-oriented: human beings are like God, and he values us highly. Although we’re focusing on Christianity, these claims can be found in other monotheistic religions, too.

. . . Clearly, there is a discrepancy between the kind of universe we would expect a human-oriented God to create, and the universe we live in. How can we explain it? Surely the simplest explanation is that God doesn’t exist. The spatial and temporal size of the universe gives us reason to be atheists.

As Everitt puts it:

The findings of modern science significantly reduce the probability that theism is true, because the universe is turning out to be very unlike the sort of universe which we would have expected, had theism been true.

She then suggests several ways that theologians could answer this argument, including the possibility that we don’t understand God’s plan, or that God simply values natural causation and lovely stars. But these seem like post facto rationalizations (which they are), and so she concludes that this is all evidence against God:

The problem with these rival explanations is that, as they stand, they are unsatisfying. They hint at reasons why God might create tiny humans in a gargantuan place but are a million miles away from fully explaining why. The weight of galaxies, and the press of years, seem to sweep us towards atheism.

Well, this is all fine and good, but is somewhat unsatisfying on three counts. First of all, it’s not a new argument, though of course hardly any arguments against God are new.

Second, theologians have other answers to the Argument from Douglas Adams not mentioned by Thomas. Michael Ruse—an atheist who specializes in helping Christians keep their faith by telling them how to harmonize science and Jesus—has suggested that Jesus traveled from planet to planet throughout the Universe, saving aliens everywhere (I am not making this up). But of course the Bible is Earth-centered. So theologians would have to claim that each planet has its own Jesus, and that God is saving different life forms in different ways—if those forms are “made in God’s image” and have souls to be saved. (In that case, what does “made in God’s image” really mean?)

Finally, there are many other reasons beyond the size and age of the Universe that already tell us that the probability of God’s existence is unlikely. And some of these arguments, like the existence of physical evils and the death of innocents and animals from horrible diseases, simply do not comport with an omnipotent and loving God—a God also described in the Bible. There’s the fact that God doesn’t show himself to us in convincing ways, and yet could if he wanted to. Why is he a deus absconditius? There are evolutionary arguments, too: if evolution is God’s way of creating humans, why all the wastage—the terrible suffering due to natural selection, and the 99% or more of species that have gone extinct without leaving descendants? Why the superfluity of species, much less stars?

Theologians have answers for these, too, for there is nothing that a clever, committed and well-paid theologian like Alvin Plantinga cannot rationalize as comporting with God’s existence. (If you can  accept the Holocaust and God at the same time, there’s nothing that can dispel your faith.) But that, too, is an argument against accepting God: if his/her/hir/its existence cannot be disproven by anything, then we need not take God seriously.

I’m not overly impressed by arguments like the superfluity of stars as evidence against a God, though it does count for something. And I’m pleased that RealClear Science is giving arguments for atheism. But Thomas writes as if scientists and philosophers like her have just discovered this argument in “the last few decades”. In fact, we’ve known for much longer that this is not the kind of universe that argues for existence of a god, and we’ve known it from several other considerations. Unwarranted suffering alone is, to me, the strongest argument against the Biblical god, for theodicy is the Achilles heel of theology.

Readers might amuse themselves by thinking up other reasons why the sheer size and age of the Universe alone do not militate against God’s existence. If you can walk like an Egyptian, you can think like a theologian.

Sean Carroll on “The Life Scientific”

February 7, 2017 • 8:15 am

You can listen for free to this 27-minute BBC podcast (and download it)  in which Jim Al-Khalili interviews Sean Carroll on cosmology. There’s no direct link, but go to the page by clicking on the screenshot, while you’ll find it at the top.

(Note: the second reader’s comment below gives a link to the direct download.)


Carroll at the LogiCal 2017 conference a few weeks ago (photo by me):


h/t: Kevin

Hubble space telescope breaks distance record for seeing stuff in space

March 3, 2016 • 3:15 pm

NASA announced today that the Hubble Space Telescope has visualized an object (a galaxy) 13.4 billion light years away. That mans, of course, that the light we see left the galaxy only a bit after the Big Bang. This is all more or less above my pay grade, but it’s still cool:

By pushing NASA’s Hubble Space Telescope to its limits, an international team of astronomers has shattered the cosmic distance record by measuring the farthest galaxy ever seen in the universe. This surprisingly bright infant galaxy, named GN-z11, is seen as it was 13.4 billion years in the past, just 400 million years after the Big Bang. GN-z11 is located in the direction of the constellation of Ursa Major.

“We’ve taken a major step back in time, beyond what we’d ever expected to be able to do with Hubble. We see GN-z11 at a time when the universe was only three percent of its current age,” explained principal investigator Pascal Oesch of Yale University. The team includes scientists from Yale University, the Space Telescope Science Institute (STScI), and the University of California.

Here’s a very short video zeroing in on GN-z11:

The announcement continues (it’s much longer than the excerpts I’ve given here):

Astronomers are closing in on the first galaxies that formed in the universe. The new Hubble observations take astronomers into a realm that was once thought to be only reachable with NASA’s upcoming James Webb Space Telescope.

This measurement provides strong evidence that some unusual and unexpectedly bright galaxies found earlier in Hubble images are really at extraordinary distances. Previously, the team had estimated GN-z11’s distance by determining its color through imaging with Hubble and NASA’s Spitzer Space Telescope. Now, for the first time for a galaxy at such an extreme distance, the team used Hubble’s Wide Field Camera 3 to precisely measure the distance to GN-z11 spectroscopically by splitting the light into its component colors.

. . . The results reveal surprising new clues about the nature of the very early universe. “It’s amazing that a galaxy so massive existed only 200 million to 300 million years after the very first stars started to form. It takes really fast growth, producing stars at a huge rate, to have formed a galaxy that is a billion solar masses so soon,” explained investigator Garth Illingworth of the University of California, Santa Cruz.

And a diagram explaining more: “Now, for the first time for a galaxy at such an extreme distance, the team used Hubble’s Wide Field Camera 3 to precisely measure the distance to GN-z11 spectroscopically by splitting the light into its component colors.”

Credits: NASA, ESA, and A. Feild (STScI) [JAC: at first I thought it read “A Felid”!]

Feser to Krauss: Shut up because of the Uncaused Cause

October 4, 2015 • 10:45 am

I didn’t know anything about the Witherspoon institute, where Catholic religious philosopher Edward Feser has published a strident piece called “Scientists should tell Lawrence Krauss to shut up already“, but it appears to be a right-wing think tank. According to Wikipedia:

The Witherspoon Institute opposes abortion and same-sex marriage and deals with embryonic stem cell research, constitutional law, and globalization. In 2003, it organized a conference on religion in modern societies. In 2006,Republican Senator Sam Brownback cited a Witherspoon document called Marriage and the Public Good: Ten Principles in a debate over a constitutional amendment against same-sex marriage. It held a conference about pornography named The Social Costs of Pornography at Princeton University in December 2008.

Be that as it may, reader Candide called my attention to Feser’s piece, a critique of Krauss’s recent piece in The New Yorker, “All scientists should be militant atheists” (my take on it here). Feser argues that Krauss doesn’t given any reason for scientists to be atheists, but in fact he does, in the final paragraph of Krauss’s piece:

We owe it to ourselves and to our children not to give a free pass to governments—totalitarian, theocratic, or democratic—that endorse, encourage, enforce, or otherwise legitimize the suppression of open questioning in order to protect ideas that are considered “sacred.” Five hundred years of science have liberated humanity from the shackles of enforced ignorance. We should celebrate this openly and enthusiastically, regardless of whom it may offend.

That seems to me pretty clear: in science no values are sacred, and it’s abandoning the notion that any ideas are beyond question—the habit of doubt that is endemic and essential in science—that militates against religious authoritarianism, endemic to most faiths. Feser also argues, contra both Krauss and me, that the empirical propositions of religion, as opposed to its moral dicta, are not questions of science:

Krauss might reply that, unlike checkers, dentistry, or engineering, science covers all of reality; thus, if God exists, evidence for his existence ought to show up in scientific inquiry.

There are two problems with such a suggestion. First, it begs the question. Second, it isn’t true.

But if in fact one construes science broadly, as a combination of reason, empirical study, and verification, yes, existence of God should show up in “scientific” inquiry.  Since it doesn’t, religionists use the word “reason” to encompass a brew of dogma, scripture, and personal revelation. But these of course lead different people to different conceptions of god. So all the “evidence” adduced by different faiths is simply a confusing muddle of different “conclusions.”

Feser instead proposes philosophy as a way to demonstrate God, starting with the ineluctable proposition that reality is real:

[The claim that we should have empirical evidence for God] begs the question because whether science is the only rational means of investigating reality is precisely what is at issue between New Atheists like Krauss and their critics. Traditional philosophical arguments for God’s existence begin with what any possible scientific theory must take for granted—such as the thesis that there is a natural world to be studied, and that there are laws governing that world that we might uncover via scientific investigation.

To Feser, the existence of the natural world is itself evidence for God, for he keeps insisting that that world had to have a beginning, and if that beginning was the Big Bang, or even if the Big Bang had a natural origin and there are universes that spawn other universes, well, those, too must have a causal chain that, in the end terminates in God.

As far as “laws governing the world,” well, that’s a result of science, not an assumption. It’s entirely possible that some physical laws might not be constant (for example, the speed of light in a vacuum might vary throughout the universe), and if we found that out, well, that would become part of science too. Indeed, the speed of light is not a constant in other media like water or glass, so the “law” isn’t universal. Other physical laws, such as those governing molecular interactions, must exist lest we not be around to observe them. In Faith versus Fact I note that the human body depends on physical and chemical regularities to function. So yes, we’ve found regularities, but that is inevitable given that that finding itself depends on regularities in the brain: a sort of Anthropic Principle of our Body.

Imputing such regularities to a divine being, much less Feser’s Catholic and beneficent God, is no explanation at all. It’s merely saying, “We will call God the reason for the constancy of nature.” Where from these regularities can one derive a Beneficent Person without Substance—one who not only loves us all, but demands worship under threat of immolation, and opposes abortion as well?

And so Feser proves the existence of God from his usual claim: the Uncaused Cause:

The arguments claim that, whatever the specific empirical details turn out to be, the facts that there is a world at all and that there are any laws governing it cannot be made sense of unless there is an uncaused cause sustaining that world in being, a cause that exists of absolute necessity rather than merely contingently (as the world itself and the laws that govern it are merely contingent).

. . . Similarly, what science uncovers are, in effect, the “rules” that govern the “game” that is the natural world. Its domain of study is what is internal to the natural order of things. It presupposes that there is such an order, just as the rules of checkers presuppose that there are such things as checkers boards and game pieces. For that very reason, though, science has nothing to say about why there is any natural order or laws in the first place, any more than the rules of checkers tell you why there are any checkers boards or checkers rules in the first place.

Thus, science cannot answer the question why there is any world at all, or any laws at all. To answer those questions, or even to understand them properly, you must take an intellectual vantage point from outside the world and its laws, and thus outside of science. You need to look to philosophical argument, which goes deeper than anything mere physics can uncover.

For a response to the “Uncaused Cause” argument, and the outmoded notion of Aristotelian causality in modern physics, I refer you to the writings of Sean Carroll (for example here and here, especially the section called “accounting for the world”), and Carroll’s debate with Feser William Lane Craig here.

No, science cannot yet answer the question why there is any world at all, or why the laws are as they are (though the latter question might someday find an answer), but neither can religion. As Caroll notes, the answer to these questions may ultimately be this:

“. .. . the ultimate answer to “We need to understand why the universe exists/continues to exist/exhibits regularities/came to be” is essentially ‘No we don’t.’

. . . Granted, it is always nice to be able to provide reasons why something is the case.  Most scientists, however, suspect that the search for ultimate explanations eventually terminates in some final theory of the world, along with the phrase “and that’s just how it is.”  It is certainly conceivable that the ultimate explanation is to be found in God; but a compelling argument to that effect would consist of a demonstration that God provides a better explanation (for whatever reason) than a purely materialist picture, not an a priori insistence that a purely materialist picture is unsatisfying.”

Indeed, theists like Feser face their own Ultimate Questions: Why is there a God rather than no God? How did God come into being, and what was He doing before he created Something out of Nothing? To answer those, some people might point to scripture or revelation, but that’s unsatisfying, for different scriptures and different revelations say different things. In the end, Feser must resort to the same answer physicists give. When told by rationalists that we need to understand where God Himself came from, Feser would have to respond, “No we don’t. He was just There.” What I don’t understand is how God can just be there, but the universe and its antecedents, or the laws of physics, cannot just be there.

Nor do I understand how an empirical proposition–the idea that there’s a supernatural being who affects the universe–can be demonstrated by philosophy alone, without any appeal to empiricism.

Cosmic inflation one more time—well, two

March 21, 2014 • 12:32 pm

Reader Sergio called this comic to my attention (via  Twi**er: @JenLucPiquant and @phdcomics), which gives a good explanation of the meaning of the recent evidence for cosmic inflation.  Maybe you understand those scientific findings by now, but just in case you didn’t read this, from Jon Kaufman and Jorge Cham at PhD Comics (Kaufman was a member of the BICEP2 team that helped make the discovery):


And here’s a video of Official Website Physicist™ Sean Carroll explaining the phenomenon on PBS (Public Broadcasting Service) and its significance. He does a very good job!

BICEP, gravitational waves et al.

March 20, 2014 • 8:10 am

Reader Justin sent a link to this animated video by MinutePhysics that tries to explain what the BICEP project really revealed about the Big Bang (I say “tries” because I’m not a physicist). Do note, though, that Official Website Physicist™ Sean Carroll was an advisor on the science, so it must be right!.

One thing I took from this video (and again, readers in the know can explain it) was the statement that “this discovery marks the first confirmation that gravity is indeed a quantum mechanical phenomenon.” It was my impression that the unification of gravity and quantum mechanics was one of the great unsolve problems of physics, and I’m wondering if the BICEP results will help that project.

Note that two minutes in, the video tells you how to get a free audio book, and the selection includes one recommended by Randall Munroe, the creator of xkcd.

As for the significance beyond physics, it’s explained in yesterday’s The Far Left Side cartoon by Mike Stanfill, a strip I must check more regularly. (Stanfill always adds some explanation below his cartoons.)


In less than an hour, scientists will announce their discovery of the Big Bang’s echo

March 17, 2014 • 8:18 am

by Matthew Cobb

For the last few days, Tw*tter has been abuzz with speculation about a press conference around a ‘major discovery’ that’s being held today at Harvard-Smithsonian Center for Astrophysics, at noon US Eastern Standard Time (16:00 GMT/UTC).  There will be a live-stream of the presser from 11:55 am EST/15:55 (as of now, the site has crashed…). If you can understand it, you can get all the raw data here.

It seems most likely that the researchers will announce that the BICEP2 experiment – based in Antarctica – has detected primordial gravitational waves in the cosmic microwave background. These would have been produced just after the Big Bang – the ‘echo’ of that event that set in motion everything that is or ever will be. And when they say ‘just after’, that’s exactly what the cosmologists and astronomers mean, for this would be a sign of the inflationary phase that followed the Big Bang, at around 10-34 seconds. That is, 0.00000000000000000000000000000000001 seconds after… The nature of this incredibly faint signal will tell us something about this key phase in the history of the universe.

I won’t pretend I understand all the cosmology (and I don’t feel bad about that – what do the cosmologists know about maggots?) but I know it’s exciting. If you want to know more, I recommend reading The Guardian’s explanation from last Friday when they blew the story wide open, or if you are more technically-inclined, this post by the Official Website Physicist™ Sean Carroll.

If—like me—you’re going to be glued to the press conference, and in particular if you’re in a group that’s watching, liven up an already exciting event by printing out these handy bingo cards, replete with all the expected clichés…

Please feel free to pitch in below, particularly if you have expert knowledge in this field. [JAC: I can’t pretend to understand the significance of this, either, even though I’ve read the relevant posts, so reader feedback would be appreciated, especially to distinguish this new finding from the older, Nobel-recognized discovery of the microwave radiation that also echoed the Big Bang.]

[UPDATE: Stanford has just posted this great video, in which Assistant Professor Chao-Lin Kuo of the BICEP2 experiment popped  round earlier on today to see Professor Andrei Linde, one of the scientists who developed much of the theory behind inflation, to tell him he was right. His response – and that of his wife – is charming. (The ‘5 sigma’ they are talking about is the significance level of the results, which is amazingly high because the data are so clear. As one of the BICEP2 researchers said during the press conference – ‘we were looking for a needle in a haystack; we found a crowbar’.)

JAC: I’ve posted a picture, noted by reader Kevin in the comments, of the timeline of the evolution of the universe, a NASA creation taken from Wikipedia: