I am not afraid to believe in the Big Bang!

Facts do not cease to exist because they are ignored. -Aldous Huxley

People who don’t like their beliefs being laughed at shouldn’t have such funny beliefs. -Anonymous

Over at The World’s Fair, the question of belief in science arose with the provocative question, “Do you believe in the Big Bang?” I thought about it for a few seconds. What popped into my head?

The thought that, 13.7 billion years ago, all of the matter and energy within our observable Universe was concentrated into a space no bigger than the size of a single proton. That the incredibly high densities and temperatures in this region caused an expansion at nearly light-speed. As the Universe expanded and cooled, protons and neutrons formed,

nuclear fusion happened for the first time, producing nearly all of the deuterium, helium, lithium and beryllium in the Universe,

and eventually neutral atoms formed, leaving behind the relic radiation from the big bang, which is still cooling today, and which has been discovered as the Cosmic Microwave Background.

“Yes,” I thought to myself, “I do, in fact, believe in the Big Bang.” It is superior to all of the proposed alternatives, it is consistent with all of our observations, and it makes predictions that have allowed us to discover new things about the Universe. What more could one need to be convinced of its validity, and hence, to believe in it?

What’s more, I reasoned, is that if an observation came up that was in conflict with the Big Bang, I would either need to explain the observation or revise my belief in the Big Bang. And if another, superior scientific theory came along, I might be compelled to believe in that in lieu of the Big Bang.

But after showing his class Lauren Gunderson’s play, Background, about Ralph Alpher (a student of Gamow’s) and the prediction and discovery of the cosmic microwave background, Vince asked his students to define “nucleosynthesis.” Let’s listen to Vince’s account:

The answer is that Big Bang nucleosynthesis is the formation of several different elements (including deuterium, helium, beryllium, and lithium) from protons and neutrons during the first 2-5 minutes after the Big Bang. What was interesting was that one student gave exactly that answer, then added “if you believe in the Big Bang.”

Now, Vince (and many of his commenters) have a problem with this. Specifically, with the “belief” aspect. The discussion spirals down into a “science vs. religion” debate after that.

Why? Why can one not believe in the Big Bang as opposed to the major rival theory of the day, the Steady State Model? (In which, incidentally, “nucleosynthesis” has a very different definition.) Why cannot one “believe” in global warming, as a preponderance of the evidence supports it, or “believe” in evolution or general relativity or any other scientific theory, as opposed to any other alternatives? Why cannot one make the best decision one can with the information available and stand behind it with conviction, whether it’s to believe or disbelieve string theory, supersymmetry, quantum gravity, or any other theory? What’s the worst that happens; that new evidence comes in and proves you wrong, forcing you to either change your beliefs or continue being knowingly wrong?

If I look up believe, I find:

to have confidence in the truth, the existence, or the reliability of something, although without absolute proof that one is right in doing so.

In science, we never have absolute proof. We are always subject to observations and experiments, and to new data forcing us to revise our theories, opinions, and yes, our beliefs. Why do we not reclaim this word, and use it to mean exactly what it means? Or, to be blunt, what, exactly, is the problem with having an informed belief in a scientific theory?


  1. #1 eNeMeE
    January 13, 2010

    Why do we not reclaim this word, and use it to mean exactly what it means?

    Too hard. Plus, scientists suck at naming things: “Giant Space Kablooey” >> “Big Bang”

    I prefer to go with “I understand [theory x] to be correct (based on [A,B,C]” when trying to say I have an informed belief.

    ‘Course that assumes the person I’m talking to knows what theory means…

  2. #2 healthphysicist
    January 13, 2010

    I’ve dumped the word “believe”, because it has been hijacked by the religious.

    If I’ve analyzed an issue, I “conclude”, not believe. The conclusion is based on evidence. This sets a conversation up to be evidence-based.

    If I haven’t analyzed an issue, I “guess”, not believe. I acknowledge I haven’t done any analysis, and will accept any evidence proffered to help me conclude.

    I have found that using those terms consistently gets people thinking.

  3. #3 Katharine
    January 13, 2010

    “In science, we never have absolute proof. We are always subject to observations and experiments, and to new data forcing us to revise our theories, opinions, and yes, our beliefs.”

    I prefer to say ‘our certainty asymptotically approaches 100%’ .

  4. #4 user
    January 13, 2010

    the only people that actually care if you use the word belief are internet losers… so do whatever man

  5. #5 John-Michael Caldaro
    January 13, 2010

    As a high school science teacher(physics) I explain to my students that the “facts” I discuss with them and the answers they give me have a certainty based on the accuracy of their measurements. These measurements are based on the detail of their instruments. A time measurement can only be as accurate as the timing device’s accuracy. I try not to use the believe word. I do ask them if the electron exists. Most say yes. I ask them if anyone has ever seen one. Most say no. (These are students in physics.) We discuss that the world operates today based on the manipulation of an unseen particle whose characteristics have been identified precisely through repeated experimentation. I then can say I “believe” the electron is real.

    I really like “healthphysicist”‘s “conclude” and “guess” phrasing. I will start using it and present that to my students.

  6. #6 Greg Laden
    January 13, 2010

    John-Michael: You are correct. As I said in a comment over at The World’s Fair, I used to use the word “Belief” interchangeably with terms like “to the best of our knowledge” and so on. Now, I try to use language that does not require choosing between the word “belief” and other terms, and this is because of the influence of my wife, a science teacher.

    But I totally sympathize with the position that it would be nice, and should not matter, to use the word “belief” when talking about scientific models and theories.

    It is hard for people who are not in the trenches in highs school science classes to get some of this stuff. The comments on my recent post regarding Joan d’Arc as a student in a science classroom demonstrates that. (click my name to see the post.) The solutions suggested for a teacher dealing with a bible thumping student were all obvious, the sorts of things the average person would think of easily and that make sense. But none of them work in the science classroom, sadly.

  7. #7 Rob C
    January 13, 2010

    I often get the conversation heated up by asking “Is it a real religion if what you believe in is actually true?”

    Quite a lot of people want to say “No!”

  8. #8 Nathan Myers
    January 13, 2010

    Classrooms ought to be easy. Anybody who gives you heat about, e.g., carbon dating, gets assigned to write a research report on the history and known limitations of carbon dating, that they will read to the class once it has achieved a satisfactory grade.

    It should have been “…, assuming Big Bang.” Even when it’s the best theory you have , it never hurts to remind yourself that, like all theories, its days are numbered.

    Judging by the first graphic in the previous posting (“Q & A”), it should be called “Big Toothpaste Tube”.

  9. #9 Greg Laden
    January 13, 2010

    I believe that it is safe to assume for the time being that the Big Bang theory (the theory, not the TV show) is the best explanation science has for all the observations we have pertaining to the origin and subsequent development of the universe to the extent that it would be surprising as significant alteration of that theory at any time in the future.

    How’s that?

  10. #10 Andrew Foland
    January 13, 2010

    I bet that not 1 person in 100 actually understands the evidence for the Big Bang, Inflation, Nucleosynthesis, Recombination, etc etc. Those who do might fairly be said to have concluded that the Big Bang happened.

    But (luckily, I suppose) much more than 1% of the populace “believes” in the Big Bang. And I think that for those people in that excess, the word belief probably is the right word!

    (which is to say, I think Ethan has it exactly backwards–he’s one of the few who might fairly say that it’s not that they believe, it’s that they’ve concluded!)

  11. #11 Greg Laden
    January 14, 2010

    Andrew, I believe, I mean, I conclude in the absence of contrary evidence but subject to revision, that you are … on the right track. As it were.

  12. #12 Nivra
    January 14, 2010

    And why you do afraid to belive in God?

  13. #13 Cents
    January 14, 2010

    I love the view that healthphysicist presented.

    This is a excellent way to look at our everyday world,the word belief indeed has been hijacked by the relgious.

    It’s like the word Atheist has been made to represent bad people when all it really means is that we will not accept something (a diety) without evidence. Great claims (of a diety or any other) require great evidence.

    This evidenced based view of the world that is what logical thinking and reason is also about and our hope for the future.

  14. #14 Cents
    January 14, 2010

    I love the view that healthphysicist presented.

    This is a excellent way to look at our everyday world,the word belief indeed has been hijacked by the relgious.

    It’s like the word Atheist has been made to represent bad people when all it really means is that we will not accept something (a diety) without evidence. Great claims (of a diety or any other) require great evidence.

    This evidenced based view of the world that is what logical thinking and reason is also about and our hope for the future.

  15. #15 yogi-one
    January 14, 2010

    Big Bang for Dummies – Cosmology for the Rest Of Us

    If you are not a scientist (like me and 99.9% of the population), you have to either make up your mind without studying the arguments scientists make for the Big Bang, or you have to realize that you are always going to be trying to evaluate research that you didn’t do yourself, oftentimes supported by mathematics that you can’t do yourself.

    That is the quandary the layman faces. We are reduced to reading stuff from the likes of Carlos Sagan, Michio Kaku, and the other scientists who have made it a priority to communicate with the “rest of us”. Does what they say make sense? They say the math proves it, but we can’t do the math.

    Here’s where a lot of scientists just throw up their hands and go back to the safety of the laboratory. After all, you have a lot of work to do, and what will you get out of spending a bunch of time explaining stuff to Stupid here, who can’t do the friggin’ math?

    But you will not win the fight against scientific illiteracy that way.

    It does come down to working on many fronts to combat science and math illiteracy, which is a whole different line of work than hypothesizing, measuring, testing, and replicating results.

    The main problem with “belief” is that it has become an emotionally loaded bomb of a word (like “God”, and “love”) that means six billion different things to each of the world’s six billion people.

    “Belief” means an emotional attachment, and even the dictionary definitions like the one you gave explicitly state that belief need not be research-based, fact-based, or tested in any way. You simply declare something and attach your righteous heart to it.

    And therein lies the problem. Anybody that questions your belief becomes, by definition, a person who is attacking the heart of your righteousness.

    And that’s grounds for a fight to most people.

    No, you can’t “believe in” the Big Bang because the Big Bang is not a belief. It was not simply declared sans evidence, and promoted to people as the righteous truth to attach your heart to, and therefore to fight for, to the death if necessary, rather than give up.

    No, the Big Bang is a theory, as science defines a theory. It’s a statement that “based on what we can demonstrate by repeated testing, and based on math that seems to hold up under repeated scrutiny by the world’s best mathematical geniuses, this is an exposition of what we think is the most likely scenario.”

    That’s not a belief. A belief is simple declaration such as “God Exists” – that’s a belief. And “God exists” is not a scientific theory.

    For me, your post is kind of scary, for it represents a point at which you crossed over from a scientific viewpoint to a religious viewpoint. When you decided to attach your righteous heart to a belief you call the Big Bang, flags go off for me, because objectivity is not a necessary requirement to hold a belief, whereas it is to support a scientific theory.

    You enter that messy territory where the scientist wades into mysticism, where you start drinking your own Kool-Aid.

    Not that mysticism is necessarily bad or wrong, but doing it while still claiming to be a scientist is, in my opinion, toxic waters to be swimming in.

    At least throw off the scientist hat when you are going to jump off the metaphysical cliff. That I have no problem with.

    And when you are being a scientist, don’t get all emotionally righteous about the theories.

  16. #16 Girlfriend
    January 14, 2010

    Interesting take on this subject. I will bookmark this site for future reference.

  17. #17 Thistlin
    January 14, 2010

    As several earlier posts mentioned, in spite of strict dictionary definitions, “belief” implies an emotional commitment that may not be appropriate in science. I prefer to say, “I think,” or, “In my opinion,” and tend to avoid saying, “I believe.”

    Besides, there are schools of thought that distinguish belief and opinion in a technical way. Here “belief” is furniture that we sit on but don’t notice–things we take for granted that generally we learned as children–such as things thrown up come back down or touching hot surfaces causes pain.

    Often what we call “conscience” (to the extent that it is culturally learned) and our innate skill with our native language, and, of course, our religion, can be traced to such childhood learning and are therefore “beliefs” in that technical sense (we are not really aware that we hold them and tend to find opposing views emotionally disturbing).

    It is also possible to convert an opinion that we learned intellectually into a belief through various techniques, such as meditation, or “brain-washing.”

  18. #18 Phaedrus
    January 14, 2010

    “Why can one not believe in the Big Bang as opposed to the major rival theory of the day, the Steady State Model?”

    Many religious people do not share your definition of belief. They’re “beliefs” are not based on a rational examination of facts but on the adherence to an ideology. This is better described as “faith”, the belief in something unseen or unproven. It in this context that most people don’t “believe” in the Big Bang, or evolution, or global warming.

  19. #19 BenHead
    January 14, 2010

    Well said, yogi-one @15. Science needs advocates, and it hasn’t had a superstar advocate since Carl Sagan. For good or bad (I think it’s bad, but we’re talking about a lot of subjectives here), people often choose what, or whom, to believe in based on how they feel. If a person isn’t trained in science (or in a specific field of science), then (as Andrew @10 said) they can only choose to believe something based on what the well-trained scientists tell them. So their belief in prevailing scientific theories is then predicated on their “belief in” scientists. And although they maybe should consider the logical side – these are well-trained people, there are far too many of them to be perpetrating a secret conspiracy, etc – not everyone will do that. So science needs advocates. It needs personable people who are willing to get out of their labs and talk to non-scientists in their own language and really connect with them. Many both in and out of the scientific field have said it (this was the primary thesis of Chris Mooney’s last book, Unscientific America), and I’m heartened to see everyone from Neil deGrasse Tyson to Ethan Siegel doing it. I hope to see a lot more of it in the coming years.

  20. #20 Notagod
    January 14, 2010

    I guess the reason we shouldn’t use ‘belief’ is the same reason we shouldn’t allow the christians to mix religion into the science textbooks that our children use, to learn what science is and hopefully conclude that science isn’t religion. It is unfortunate that christians want to force their religion into everything, not just biology but, all science, all government, and all of everything. Bad things happen because christians and other creationists don’t believe in the limits of their belief.

    Sure we have the right to reclaim the word belief, and many other words and thoughts that christians use to spin their deception but, at the risk of equating science to christian belief. The christians will also continue to hijack and twist other words, concepts and, thoughts in the future. Deception is the foundation of the christian religion. The only type of word I believe (as I am very unsure) that the christians wouldn’t try to hijack and twist would be something like friedchrist. Such as, I friedchrist that apples will never fall up from the planet earth. As christians do complain, it will be necessary to remind them that they bake it.

  21. #21 crd2
    January 14, 2010

    @ Yogi-One,

    I think you are making an incorrect correlation when u state that having a belief in the big band should be one that u would die for as one would for a particular religious belief. The Big Bang Theory and, let’s say the belief that Christ died for your sins, aren’t even in the same ball park when it comes to an individual’s convictions. What I’m saying is, not believing in the big bang does not hold so dire consequences as say not believing in Christ in some peoples mind. If I choose to not believe in the big bang the repercussions aren’t necessarily that I’m going to spend the rest of my post-life existence burning in an eternal fire where as a religious belief one is inclined to think that. So to say that Ethan should be prepared to defend the big bang to the death is a bit extreme.

  22. #22 jdhuey
    January 14, 2010

    Each of us creates the universe within our brains based on all that we experience in our lives and within this mental universe is a self-referential strange loop that is our conception of ourselves. What we think we are is determined by what we believe the universe is like. All ideas and concepts that flow through our minds go into shaping and informing our self-concept – even things you don’t ‘believe’ in shape you because your self-concept includes this dis-belief. But, obviously, some beliefs have a greater impact on our self-conception than others. I think that it is this relative impact on our self-conception that forms the basis for the emotional reactions to beliefs. If changing your belief status about a theory doesn’t cause you alter your vision of your self (and your relationship to the universe) then it becomes an intellectual evaluation process based on the evidence just like Ethan described. Conversely, if who you think you are is going to be radically changed if you change your belief then much more than a simply balancing of the evidence is going to be required.

    And this is where the religious component comes in: Religious beliefs are usually very central to a persons self-conception. So, when we talk about believing in the Big Bang Theory we are also talking about accepting a certain type of self-conception that can be fundamentally different than the self-concept built up in the religious persons mind.

  23. #23 Warren
    January 14, 2010

    Like others here, I’ve stopped using “believe” when I discuss things that fall under the realm of scientific inquiry.

    I prefer to say, “I accept the validity of…” instead.

    Or, if I’m feeling snarky, I’ll pull gravity into it: “Yes, I ‘believe’ in evolution, in the same way that I ‘believe’ in gravity.”

  24. #24 MadScientist
    January 14, 2010

    Standard creationist tactics include conflating belief based on evidence with belief based on “I told you so” and threats of hell. For many religious people there is only one definition of “belief”: unwavering acceptance of some nonsense claimed to originate from a divine being.

  25. #25 Nathan Myers
    January 16, 2010

    The moment you start believing in a theory, you stop being a scientist. There are worse fates, and it’s a matter of choice. You don’t have to be a scientist about everything. But don’t pretend.

  26. #26 Duncan Ivry
    January 16, 2010

    Well, let’s take gravity at work. If a stone of known mass falls from my table to the floor, I can calculate the point in time, when it will hit the floor — and this i *know*, it is not appropriate saying that I *believe* it. Over and above that, it’s not … er … “necessary” saying — like has been proposed by other commenters — “I understand [theory x] to be correct …”, “guess”, “our certainty asymptotically approaches 100%”, ” a certainty based on the accuracy of … measurements”, “I accept the validity of…”. With all due respect … er … no, I will not say, what I think about these formulations, but I think you know what I mean.

  27. #27 SimonG
    January 20, 2010

    If I think I’m about to get into an argument about science and religion etc I tend to inquire about definitions early on.

    But beyond that, I don’t think that “belief” accurately describes my views.

    In principle, science is repeatable. There’s nothing any scientist has done or seen which any other scientist couldn’t repeat, if they had the time and money. (Of course, that was probably a lot easier a couple of centuries ago: not many people are going to build their own LHC.) So what I really have is not belief in the Big Bang, but trust in the scientists who verified all the evidence for it.

  28. #28 Timo Ostrander
    January 27, 2010

    i agree…. the point is that (given the connotations of belief and the dangers posed by them in the religion vs. science debate) you have to maintain that it is an informed belief based on reason and critical thinking, not a belief based merely on subjective feelings within our hearts. belief is not a dirty word; faith perchance is.

  29. #29 Britchick
    February 27, 2010

    I happen to believe that the ‘big bang’ is true, HOWEVER, that’s because if I remember rightly, at last look, science discovered that the bang was started by a soundwave… perhaps a ‘Word’ being spoken? I don’t see why you can’t use physics to prove the existence of God as opposed to proving He doesn’t exist. There’s nothing that says he can’t use any natural phenomenon to do what he wants to do!

  30. #30 Jeff Mitchell
    April 8, 2010

    The big bang theory ranks right up there with the flat earth theory and the earth as the center of the universe theory.
    The Galaxy Spin Theory has two premises: 1. The galaxies are in orbit. 2. Light is bent by gravity. All the nonsense of the big bang: dark matter, dark eneregy, a singularity, can be put to rest by those two statements.http://www.youtube.com/watch?v=eE5FBT6Fr_s Galaxy spin is a logical explanation of the observations. No, no deities.

  31. #31 Mr james
    May 5, 2010

    You all are lonley. and spread aids

  32. #32 Mini
    May 17, 2010

    can i ask about how the sun was born?

  33. #33 palak mehra
    August 16, 2010


  34. #34 palak mehra
    August 16, 2010

    please i have still not understood what is bigbang from your site sorry please make it more clear..

    thanking in anticipation

  35. #35 Lilly
    August 26, 2010

    No matter how much I look at Big Bang Theory its seems ridiculas to me. First of all because its contradict its own lows of physics, like – 1. No thing can be created out of nothing and no thing can dissapear into nothing – means everything get recycled around and cannot come out of one small dot, even nucler energy size of 1 dot cannot create universe or even enough energy to create materials for 1 moon (sort of speak). 2. How they know that WHOLE Universe is expending? nobody ever saw all Universe or even ever got a blure idea of the size. Maybe its expanding on 1 side and contracting in the same time on anohter side? Just like so called “blackholles?. Maybe its only 1 part of Universe that WE SEE is expanding? (Wasn’t it the big deal in the Theory of the earth been the center of the Universe? People belive in what they can see and what easy fits their own logic and imagination). 3.Its contradict also another low of physics – Universal expansion getting faster and faster- if you push something with whatever type of energy, it will move fast at first with all strainght of power applied and then slow down, so how come universe is expanding faster and faster? But it the same time they say “its cool down”? Cool would mean less energy – not more. 4.Dark meter, dark energy and another dark crap that nobody ever saw or could proof – sound like crap to cover holles in any theory. When they stuck in their own BS they come out with new demention ( I cannot even count anymore is it 10? 11? or 12?) or new type of energy. Oh yeah, sometime with multiple string theories..
    I think scitist should scrap all crap and start to look into something completelly new. Here is my theory: Universe is build out of meter that endlessly recycle (just like everything on earth recycles) only its happens through channels similar to blackwholes, expends, go in circle and then contract and move into a channel(blackwhole), accomulate and explode/expend again. And this is could be multiple channels creating multiple universes to the ethernety (just like galaxies in our universe) – with a cannel (blackwhole like) in the center of every Universe (if galaxies build that way, isn’t it logical to imgine that Universe build the same way, don’t we see everyday principals of very small apply to very big as well? the part of universe tha we see could be size of the dot on you computer screen as whole may look completelly different then you think. And whole universe could be only one of the billion universes that created somethimg bigger and so on to ethernity? Well i guess its hard to imagine even for a scintist, because we cannot even imagine size of our own Universe.

  36. #36 Jeremy
    August 26, 2010

    @Lilly. I am not a scientist but I think I can sort of answer some of your queries. I will answer them out of order.

    1. This is a philosophical question and I don’t think anyone knows the answer. Although matter and antimatter do anihilate one another into ‘nothing’ and dark energy is created out of ‘nothing’ from gravitational energy (refer to 3). Also ponder this – if you divide zero what do you get? -1 + 1 = 0. Although you say there isn’t enough energy in one dot to create the universe. This isn’t the case. As time changes density changes. At the very early universe the density was just ridiculously big.

    2. All data point to a homogenous expanding universe, expanding at all points (at least between density clusters). The most famous example probably red shift – pretty much every galaxy we look at is red shifted, and the amount of red shift is dependent on distance (distance is gleaned from the distance ladder measurements e.g. white dark supernovae type 1, cepheids, triangulation etc). Another famous example is the hubble law – galaxies further away from us are moving faster. It is VERY well verified that the universe is expanding everywhere.

    3. The universe didn’t always expand ever faster and faster. After the initial inflationary period – which brought the universe into the radiation era (radiation most common cosmic constituent) – the universe was decelerating. This was the case in the matter era (matter most common cosmic constituent), too. Only for the last few billion years or so, in the dark energy era has the universe been expanding.

    These different eras are all due to the different ways in which different cosmic constituents change their density with expansion (eg radiation changes its density with the inverse to the power of 4 function). In the case of dark energy, its density does not change with expansion. At the beginning of the universe, the total dark energy was very small relative to the other constituents but radiation and matter have been ‘diluted’ by expansion so much that dark energy is now dominant. Now to the crux of your question – how can the density not change i.e. how can something come from nothing?

    The answer is from gravitational energy. In fact the total energy of the universe sums to zero if you convert all mass into energy (E=MC^2) and then add gravitational energy! Now Refer to the formula GE = -GMm/r (Newtonian law is actually a VERY good approximation of einsteinian gravity due to the homogenous nature of the universe). Normally with an increasing radius gravitational energy will become less negative i.e. expansion will decelerate. However, with increasing radius AND increasing mass (because there is more vaccum energy with more radius as its density doesn’t change), gravitational energy becomes _greater_ and more _negative_ because mass increases in proportion to radius _cubed_. This is downhill, and it is this energy that can be converted to vaccum energy (dark energy). In other words the universe is a self generating expansion machine and _falls_ outwards freely with nothing to stop it and it just gets faster and faster!

    4. Dark energy is not a firm theory yet but is pretty close. Dark matter on the other hand has a lot of independant indirect evidence supporting its existance. Examples that come to mind include predicted versus observed rotation curves of galaxies, galaxy masses not being accounted for by atomic matter and central black holes, the euclidian universe, simulation data and a host of other evidence that I can’t remember.

  37. #37 Will
    November 25, 2011

    As a kid I naturally believed the universe went on forever and was always here and I didn’t have any reason to think this odd. Then as a teenage I learned about the big bang and believed that for about 10 years but I never really questioned why I believed. But I now have gone back to what feels natural and that if that the universe has always been here and that it has no end.

  38. #38 sofia
    October 17, 2012

    no me sirbio para nada