Note: There is a special note to teachers at the bottom of this post. If you’re a teacher, please be sure to check it out!
My friend Tina is a teacher at the Saegert Sixth Grade Center in Austin, Texas. She asked her sixth grade students to send me questions they had about astronomy, and I answer them on camera. There were so many I had to split this into five parts! I’ll be posting one part every day, first thing in the morning. To catch you up, check out Part 1, Part 2, Part 3, and Part 4. Below is Part 5.
I only have one question in Part 5: What is the Big Bang theory, and is it real?
This is the last installment of this video series, but I think it has a bigger and more important message than the other four. That starts at 2:54 into the video. I got the wind in me, and decided I would take the opportunity to pontificate a bit.
SPECIAL NOTE TO TEACHERS: Many schools block access to YouTube. There is another video hosting platform called TeacherTube, which is designed to be used in schools. I’ve uploaded this video (Part 5) to my channel there, where you can access it in your school (note: the video is in higher-resolution on YouTube). If you do, please let me know! I’d love to know what the students thought of the video — warts and all.
May 23rd, 2008 at 8:41 am
I’ve enjoyed these videos; they’re very interesting and well explained
May 23rd, 2008 at 8:49 am
Phil, I loved the editorial comment at the end. The explanation of the difference between hypothesis and theory, how one becomes the other, how each continues to be tested against new observations, the need to admit when you’ve been wrong; excellent popularizations of these concepts.
Better yet: “…everybody is a scientist.” That’s the spirit! Great job with the series.
May 23rd, 2008 at 8:50 am
Anybody else catch the Pale Blue Dot radio segment last night? It featured one Phil Plait who talked about the Moon Hoax, balancing eggs, and other topics.
May 23rd, 2008 at 8:59 am
Hi Phil,
Love your site. I check it everyday.
How can those of us who are deaf obtain a transcript of the videos?
Thanks, Ray
May 23rd, 2008 at 9:08 am
Ray, that’s a good question, but I’m sorry I don’t have a good answer. I’m just one guy at home putting these together, and I don’t have the ability to put up a transcript. Maybe someone else can transcribe them if they want, but that’s a WHOLE lot of talking I did…
May 23rd, 2008 at 9:27 am
RE: Ray
AAAAargh, I, a hearing able person, run into this far too often. There needs to be a tool for hearing impaired web users to be able to enjoy the sites we encounter without waiting for transcription or description from the hearing world. Techs out there, work on it, I can’t, I’m ignorant (hence my name).
Also drunk, so I think this post doesn’t make sense (I hope it does).
May 23rd, 2008 at 9:29 am
“Everybody’s a scientist.”
I really like that. A lot.
Great series, Phil. Thanks for posting it.
May 23rd, 2008 at 9:33 am
Great job on the videos Phil.
May 23rd, 2008 at 9:36 am
@Ignorant Atheist and Ray.
I agree! How hard could it be?( For all I know it could be REALLY hard, but SOMEONE should be able to help. I will do some asking around at the BDA and others that I know
May 23rd, 2008 at 9:38 am
A poet?
Great series though. Hope you do it again sometime. Apropos for adults and children!
May 23rd, 2008 at 9:48 am
As far as transcription software available, there are speechwrite programs out there that take sounds and turn them into text. Not sure how well they work though – my last experience with them was in the 90s, and it didn’t work too well. Quite probably they have improved since then.
Quick google search brought this up:
http://www.voicerecognition.com/icommunicator/
Not sure how helpful that would be. For videos, it might work if you put a microphone up to a computer speaker to get the text in a program like this.
Hope this helps.
May 23rd, 2008 at 10:02 am
I enjoyed this series. It brings back fond memories of why I came to this site in the first place, as well as memories of my obsession with Carl Sagan in high school and university.
May 23rd, 2008 at 10:03 am
Re: the transcript…
If there are programs that take writing and turn it into speech (I use them for reading blogs and forums while I’m working on illustrations XD), there must be some for translating speech into writing, although I imagine the translation in that direction is a lot harder because it would have to account for variance in accent, pronunciation etc from person to person.
(after a bit of googling) As I thought, it’s a lot trickier to do, but there are people working on it open-source. Here’s a bit more info:
http://www.choice.com.au/viewArticle.aspx?id=104265&catId=100461&tid=100008&p=1&title=Convert+speech+to+text
To Phil:
I would have been really excited by that as a kid, and even though it’s mostly covering stuff I’m familiar with now, it’s still exciting to hear you talk so clearly and with such enthusiasm. I wish there’d been someone to describe the scientific method to me as eloquently as you do in this last video too!
Awesome series
May 23rd, 2008 at 10:22 am
Phil, I hope your enthusiasm for science is infectious for these kids as Sagan’s was for me. It will be a sad sad day when we completely understand the universe and have no more questions, no new discoveries to make.
May 23rd, 2008 at 10:33 am
TSFrost: “Phil, I hope your enthusiasm for science is infectious for these kids as Sagan’s was for me. It will be a sad sad day when we completely understand the universe and have no more questions, no new discoveries to make.”
Luckily we are nowhere remotely close to that. The end scene of 2001 is still totally true. We are still less than infants.
May 23rd, 2008 at 10:35 am
Something rings a bit false about your comments on science. The most important part of science isn’t asking questions, it’s testing those questions.
I could easily see a listener saying along with you, “I think he’s wrong”, and continuing with, “because the Bible says so”. It’s not enough to think up questions if you don’t go out and investigate.
May 23rd, 2008 at 10:52 am
@Ray and others who want a transcript
***********************************
Phil Plait”
“Can I describe the Big Bang Theory and do I think that it’s real?”
Okay, yes. The Big Bang is a model of how we think the Universe began and it is the best model that we have. It seems to explain most of what we see about what’s going on out in space. Basically what we’ve observed is that distant galaxies are moving away from us and no matter where we look in the sky we see galaxies moving away.
And we think that’s because the universe itself is expanding, and if the universe is expanding that means that if you sorta, y’know, run the clock backwards it gets smaller in the past and there must have been some point in the past–like if you’re inflating a balloon, right, and you run the film backwards–at some point in the past the balloon was at some smallest point and we think the same was true for the universe. You run the clock backwards, the universe all existed at one point at the same time and it’s at that point we think that’s what the big bang was that there was just a sudden moment and the universe itself was created and started to expand–all the matter! all the energy! everything was packed into that that one spot at one time and then it started to expand.
But people like to think of this as sort of like an explosion in space like if your blowing up a firecracker or a bomb or something but that’s not really true that’s a misconception, but the truth is much harder to understand. We think that the big bang was not an explosion in space. It was an explosion _of_ space.
Space itself formed in the big bang. There wasn’t space before that. There wasn’t any time before that. When the big bang happened it formed space. It formed time. And space itself started to expand at that moment but it as weird as it sounds it sure explains a lot of what we see: that we see galaxies moving away from us; that we see certain structures in space; that galaxies appear in clusters; we see all sorts of other things that support the big bang, but its not a matter of belief.
It’s a matter of evidence, and really astronomers–if the big bang were not right, if we thought it were wrong, we would throw it in the trash can and start again. Um, we’ve had to modify it. We’ve had to change it a little bit. There have been some things we think, well it doesn’t explain this very well but maybe this happened later.
So the big bang is really a model of what happened right as the universe formed. After that, we’ve added things to that theory to make it more accurate. But we really do think that this model, y’know–encompassing all the stuff that we that we’ve looked at and added onto it–we think this is it. This is the best explanation of what’s going on. There’s still details we don’t understand, uh. There’s a whole lot to learn about the universe, uh, the universe itself let alone the stuff in it, um, but the more we study it the more we think the big bang is right.
Um, and let-let me end this with one thing: science itself is not like a book you pick up and read stuff and say oh this tuff is what’s going on. Science s a process. It’s almost like a living thing we learn from-from observations. We observe things in-in space. We observe things in the classroom, and we study them and we say, ‘why is that happening, I wonder?’ and we come up with a guess called a hypothesis.
And we say maybe this is why that’s happening. And then we try to observe more things to see if our hypothesis is right or wrong, and we build on it and build on it and build on it. If it turns out that the hypothesis is really strong we-we-we call it a theory. It kind of graduates and becomes a theory.
But you know what happens if eventually we learn something that shows that that theory is wrong? Phbbt! Out it goes! We start again, or we modify the theory to make it fit, um, without trying to change its basic stuff. If the basic stuff is wrong, its gone!
Science learns. Science grows. And so the-the more we do it, the more we observe things, the more we think about stuff, the better we get at it and the closer we get to what we think is truth. And so that’s why science is so cool! It learns and it changes and it corrects itself. If we find something that’s wrong, we say, ‘huh! That’s wrong. We’d better look at this again.’
And so admitting that your wrong is an important part of science. Observing what’s around you honestly is a critical part of science, and that’s why we think its so good at understanding what’s going on
And so you guys are doing science in your classroom. By listening to me you’re kinda doing science, but y’know what? Stuff I said might be wrong! You need to think about it and say, ‘y’know, that guy, he’s, y’know, he’s an astronomer and everything but something he said was wrong and I think it’s this.’–You’re doing science!
Science is asking questions. Asking questions is the _most_ important part of science because that’s the only way you can learn, so I am thrilled that you guys had such great questions for me. I was really happy to be able to answer them. I hope if I couldn’t answer them the way you wanted, you’ll go online, you’ll go to books, you’ll ask other people, and you’ll learn more.
Because when you guys are older, maybe you’ll be scientists, and even if you’re not a scientist you could be a poet, you could be a teacher, you could be anything. Just asking questions, just learning about the universe around you, that makes you scientist. So everybody’s a scientist! And I-I-I really hope that you can keep this up and that when you’re older you’re still interested in this stuff, because it is so much fun and there’s so much beauty and so much joy in figuring this stuff out.
And I know that your gonna love this stuff for the rest of your life!
****************************************************
I typed that up from the video. It’s terribly authentic! I included all the ums, uhs, and stutters >:) The Bad Astronomer speaks a million words a minute and doesn’t believe in periods. I hope you enjoy the transcript as much as I enjoyed BA’s video. For extra fun, watch the video while you read and match up BA’s zany expressions and body language!
May 23rd, 2008 at 11:03 am
That was beautiful. And poetic.
One of the Pharyngulistas nominated you for Charming Spokesperson for Science. I can only join in the vote.
May 23rd, 2008 at 11:03 am
Great series of videos, and I loved the explanation of what science is at the end.
I do have a question though, regarding the Big Bang theory. You mentioned that the universe is expanding and that every direction we look, we see galaxies moving away from us. However, in the previous video, you also talked about galaxies colliding, and that way, way in the future, Andromeda and the Milky Way would collide. How do those two ideas reconcile?
May 23rd, 2008 at 11:17 am
@ Todd W:
Real quick, cheesy analogy: Fling a bucketful of sand into a wide arc. The cloud of sand grains will expand into a broad semi-circle. But you can see that, while the cloud is expanding, some individual grains could still collide with each other.
May 23rd, 2008 at 11:29 am
Adding to dpawtows response to Todd. W, I found this article that seems to make sense:
http://www.physlink.com/education/askexperts/ae384.cfm
May 23rd, 2008 at 11:30 am
Todd W., essentially it’s a difference of scale.
On all scales, every hunk of mass in the universe attracts every other hunk. On the large scales, expansion rates far exceed velocities that can be generated due to gravitational attraction. On smaller scales, this is not so.
Not only does one see (almost) all galaxies moving away from us, they move away *faster* when they are further away.
I hope this helps.
May 23rd, 2008 at 11:37 am
*clap clap clap* Nice job!
Positives: You were enthusiastic. The whole thing was well-organized, and I think you did a good job gearing this for a younger audience. You simplified things while keeping the correct the information. You presented each question visually, and re-stated it verbally, before answering. You used lots of different levels vocabulary to explain the same concept. Like when you used the term modify, you also used the term “change.” And “that’s not true,” with “misconception.”
Negatives: You seemed almost a little *too* enthusiastic on the tape. It looked a tad forced. Also echoing John Armstrong’s comments that it would have been helpful to emphasize the investigation part of science a little more at the end.
Then again, kids like to ask questions and don’t like to investigate nearly as much, so I think you were going with your audience, there.
I give you an A.
May 23rd, 2008 at 11:43 am
Really nice work, Phil! I enjoyed them all and I’m sure the kids, and your other viewers, will as well.
May 23rd, 2008 at 11:57 am
Great videos. I enjoyed watching them with my kids.
My nine year old asked me this after watching the video #5:
BA, you said that all galaxies are moving away from each other, which could suggest that all the matter and energy could have started out as a point source. Forget the point source for now.
Her question was if all galaxies are moving away, then why do galaxies collide, which you covered in one of the previous videos – 3 or 4?
I did not have a good answer to that. I said that some galaxies may move “away” quicker than the other in its path or that the gravity “well” could be more massive for one galaxy than the other in its path. I don’t know if I convinced her or not.
SRM.
May 23rd, 2008 at 12:07 pm
@all those who answered my question
Thanks for the insights. I figured that it was something like that.
Next question. Dr. Plait mentioned that there is no real “center” of the universe and no real edges. Is it possible, therefore, for something to appear to be running counter to what is expected if the universe were expanding from a starting point? E.g., we see some nearby galaxy (A) appearing to head away from us toward a hypothetical “center” and a more distant galaxy (B), in the direction of A from us but past the hypothetical center, heading toward us. Or, to use the bucket of sand analogy, for grains of sand in the expanding cloud to be heading back toward the bucket?
May 23rd, 2008 at 12:39 pm
Todd W., there IS no center. Well, more precisely, every point is the center.
The shortcoming of the “bucket of sand” analogy (as well as the related raisin-bread analogy) is that they suggest a center and a boundary. For the analogy to work, the bucket of sand has to be infinitely large.
Though it’s only 2D, I prefer to use an inflating balloon analogy instead. Paint a bunch of dots on the balloon. Then inflate it. The dots all get further away from one another, faster with greater distance.
Part of the analogy is that the “galaxies” (dots) only see the surface of the balloon. So, there is no center and no boundary, just like there is no spot on the surface of the Earth you can call it’s “center.”
This analogy has limits as well, but at least it shows you don’t have to have a center or boundaries in order to have expansion.
May 23rd, 2008 at 12:39 pm
@Todd W.
Another way to look at it might be something like this:
Wrap a bunch of magnets around a spherical explosive. Set off the explosive. Mostly the magnets will each go their own separate ways, but some of them will be close enough to each other that they will attract each other WHILE STILL CONTINUING TO MOVE AWAY FROM THE INITIAL EXPLOSION.
May 23rd, 2008 at 12:40 pm
Richard, wow thanks!
May 23rd, 2008 at 1:06 pm
Phil, that was beautiful. Thanks for posting and thanks for your enthusiasm, it IS infectious. I really hope you managed to inspire some little Phil or Philippa to become the next Bad Astronomer/Biologist/Chemist/Palaeontologist/Archaeologist or whatever. Actually, I’m quite positive you did. Please keep on doing these things, it’s a marvellous gift.
May 23rd, 2008 at 1:26 pm
This was an excellent series! Thanks so much for doing it and doing it so well.
You should get your own TV show, Phil…
May 23rd, 2008 at 1:58 pm
Great video Dr. Phil..
Off topic:
By the way, I saw in Wikipedia that the Mythbusters will be making
a “NASA Special”, and one of the myths that they will be debunking
is the Moon Landing Hoax:
http://en.wikipedia.org/wiki/MythBusters_%28season_6%29
Since you are acquainted with Adam, and since you are well known as
one of the Defenders of the Moon Landing, will you be guesting on the show?
Coz dat will be cool.
May 23rd, 2008 at 2:03 pm
decided I would take the opportunity to pontificate a bit.
Pope Phil the Phirst?
J/P=?
May 23rd, 2008 at 2:07 pm
Richard,
THANKS!! “For extra fun, watch the video while you read and match up BA’s zany expressions and body language!” I will do that.
Ignorant Atheist, Madge, Justin and Paul (hope I didn’t miss anybody),
Thanks for your comments and advice.
Phil,
No apologies necessary. All of us appreciate what you’ve done on this website. Great work.
Ray
May 23rd, 2008 at 3:14 pm
That was a truly amazing way to end the series. I loved the key point of belief in something versus accepting something on the evidence. I find that this gets things muddled up in science discussions when someone exclaims, “Well, you just believe in in the same way that I believe in , it just comes down to belief!” when that is not the case at all. Evidence removes the need to “believe” in a scientific theory.
I especially like the, dare I say Sagan-esque, treatment of the joys of science and learning. Kids today too often are given the impression that science is either simply memorizing chapters for a test or old guys in libraries debating their pet theory, while the truth of the matter is that science is at its core about going out into the world and knocking down our old misunderstandings and boundaries of ignorance and replacing them with truth and understanding.
Great job, and I hope you truely inspired some young minds.
May 23rd, 2008 at 3:41 pm
I typed up a transcript of Part 4 (find it here: http://www.badastronomy.com/bablog/2008/05/22/astronomy-questions-from-sixth-graders-part-4/#comment-177528)
I can use the typing practice, and it’s embedding the knowledge more firmly in my memory banks. If I have time to type up the others I’ll post them in the original threads and link here.
May 23rd, 2008 at 8:19 pm
Is… is that Astronomy for Dummys on your bookshelf???!?
May 23rd, 2008 at 11:23 pm
Your enthusiasm is as infectious as that or Carl Sagan himself.
May 23rd, 2008 at 11:51 pm
I have a basic question about the BB theory. It’s stated that time started at that point, that there wasn’t time before that point. (I
won’t belabor the idea that saying “before that point” is making a
time-based statement.)
Time not existing, then starting, just doesn’t make a lot of sense to me. What’s the evidence for that conclusion?
May 24th, 2008 at 12:24 am
A fine quote from Phil Plait:
“Science is asking questions. Asking questions is the _most_ important part of science because that’s the only way you can learn…”
As I recall from sitting in the theater watching “Expelled” about a month ago, that is what those interviewees were doing — asking questions about evolutionary thinking that’s become so dogmatized that those in charge of it don’t allow questions to be asked!
A second fine quote from Phil Plait:
“Space itself formed in the big bang. There wasn’t space before that. There wasn’t any time before that. When the big bang happened it formed space. It formed time.”
OK, so Phil says that nothing, surrounded by nothing, compelled by nothing, became space, and there was no preparation or countdown because there was no time to count down. A universe seems like a pretty complicated something to come from no-thing, no-when and no-how.
And yet he ridicules me because I can confidently say “In the beginning, God created the heavens and the earth…”
May 24th, 2008 at 3:30 am
I enjoyed much of the video series, but I have some quibbles with part 5.
1) Phil leaves the impression as if the main statement of the Big Bang theory is about that and how the universe began. That’s not true – the Big Bang theory (as conceived today, probably not as conceived originally) does *not* tell us really how the universe began, but how it developed since its beginning. How the universe really began is so far still a mystery – because we simply can’t extrapolate back the theory to time zero. The theory yields then infinite answers (a “singularity” appears). It’s quite clear to most cosmologists that we’ll need a quantum theory of gravity before we can actually adress the beginning of the universe.
For more details, see here (A FAQ page written by a professional cosmologist and by me, peer-reviewed by several other cosmologists):
http://www.talkorigins.org/faqs/astronomy/bigbang.html#misconceptions
http://www.talkorigins.org/faqs/astronomy/bigbang.html#origin
I hope this also addresses some of jim’s and DaveS’s concerns…
2) Phil says that the universe started from a single point. That’s only true if the universe has a finite volume, and that’s only true if the universe is closed. So far, the evidence seems to say that the universe is flat and hence infinite (although the evidence isn’t yet conclusive on that), and hence never was point-like. See also the first link mentioned above, and
http://www.talkorigins.org/faqs/astronomy/bigbang.html#theory
3) Phil states essentially that a (scientific) theory is a well-confirmed hypothesis. I think that’s not entirely right; AFAIK, a theory is more like a bunch of closely connected, interlocking hypothesis, having a wider scope, explaining a whole area of science consistently. A hypothesis does not become a theory once it is confirmed – it simply becomes a confirmed hypothesis. Also, a theory is not a hypothesis as long as it has not been confirmed – it simply is an unconfirmed theory.
And a theory becomes confirmed by checking what predictions it makes
(these are then hypotheses about things one can observe), and confirming these predictions (hypotheses).
An example: Maxwell’s electromagnetism is a *theory*. A part of that theory (a prediction of that theory) is the *hypothesis* that electromagnetic waves exist and travel with the speed of light.
That’s my understanding of the terms “theory” and “hypotheses”; correct me if I’m wrong…
Finally, a short reply to jim: “evolutionary thinking” has *not* “become so dogmatized that those in charge of it don’t allow questions to be asked”. I wonder where you got that idea from! Please provide evidence for that assertion. BTW, pointing out that evolutionary biologists think that ID is crap and should not be taught in public schools is not evidence for your assertion. And another BTW: “Expelled” was not simply about “asking questions” – it was full of lies, if you haven’t heard. Educate yourself a bit here: http://www.expelledexposed.com
May 24th, 2008 at 4:50 am
A great conclusion to a great series!
Is there going to be a season 2? Euh… I mean, a series 2?
May 24th, 2008 at 8:50 am
Ack, don’t lump me in with an “Expelled” fan! I’m not denying science, or anything about BB theory.
I’m simply asking how they came to the conclusion that time began at the BB, and didn’t exist before that, when an alternative model might be that time existed before that, and at some particular spot in time, the BB happened.
What observation prefers one model over the other?
May 24th, 2008 at 10:09 am
@DaveS:
Sorry, I didn’t mean to “lump you in” with jim.
To answer your question: that time began with the BB is not based on an observation – at least not directly.
It’s more like this: applying the General theory of Relativity (GR) to the universe as a whole, it turns out mathematically that the universe either has to expand, with a definite beginning (and no time before), or has to contract, with a definite end in time (and no time afterwards). Since we observe the universe to expand, it’s the first one – and hence no time before.
I don’t know of a model with time before the BB which is consistent with GR, and judging from my (admittedly limited) experience with GR, that’s not possible.
HTH.
May 24th, 2008 at 2:17 pm
question @the Bad Astronomer:
Did you ever think about setting up your camera somehow different, or using a neutral background? Apart from that making the job easier for the compression algorithms, I find myself strangely distracted by the bookshelf, and also wondering why you’re so far out there on the left side
May 24th, 2008 at 4:00 pm
Great. One can’t inspire the younger generation enough. I happened to be way into my twenties before discovering science is about reconsideration and arguing instead of learning cold facts. Attitude means a lot.
May 24th, 2008 at 7:18 pm
I’d like to see some videos for grown-ups (I don’t want to say adult because I don’t want to see you with your clothes off), especially explaining the moon hoax issue.
May 25th, 2008 at 11:56 pm
I really like how eager you are, Phil. It’s infectious.
May 29th, 2008 at 4:08 pm
DaveS said:
> I’m simply asking how they came to the conclusion that time began at the BB, and didn’t exist before that, when an alternative model might be that time existed before that, and at some particular spot in time, the BB happened.
Bjoern is correct, it has to do with General Relativity. Specifically, the nature of time and its relationship to space. GR says that time is in essence the same kind of “thing” as space, i.e., a dimension. There are three dimensions of space and one of time, interlocked and inseparable.* The Big Bang was the starting point for the expansion of spacetime (the set from above), therefore, there was no time without spacetime.
This is admittedly incredibly difficult to grasp, because our nature is tuned to see things temporally. We define the question with temporal concepts. “What came before the Big Bang?” is a time question. To say there was no before the Big Bang creates a mental paradox.
May 30th, 2008 at 7:08 pm
[...] Part 1, Part 2, Part 3, Part 4, and Part 5 [...]
June 3rd, 2008 at 9:42 pm
[...] Astronomy questions from sixth graders, Part 5 (phew!) Phil talks about the Big Bang and goes off on the joys of science. [...]