This is a point that is often ignored by most "science popularizers" (and, unfortunately, many science teachers): that science is a process, not a list of facts to be memorized. Explaining how we know an answer is at least as important as answering a question. Kudos, Dr. Becky.
Perhaps, if people knew there is no truth in science, nothing is ever settled, and no theory has ever been proven to be the "Truth", then perhaps the political purposes of the 4th Reich could be separated from humanity's desire to elevate itself above the status of biological robots serving any world order.
Not as important, knowing the meaning behind it is totally the point. I went through my homework when I was young, at a lower level, grabbing books of a higher level to be able to understand things. If not, I had a hard time memorizing things or simply "taking it for granted". It took me hours more, but am glad I did it. As Feynman once said "I learned early the difference between knowing the name of something and knowing something. "
Yes, but simplistic answers allow the priesthood to maintain their monopoly as intermediaries between Science and the unwashed masses. _"If I omit the most basic questions about how humankind figured this out, then I'll look like a genius, and it'll generate an assload of obsequious flattery in the comments section!"_
Except, she forgot to mention (i guess not to confuse the unsuspecting public), that there are some major well known and unexplained problems with the suns nuclear fusion model...but, i am sure she can answer these questions. ruclips.net/video/ezHBuvDxihE/видео.html Because, if the sun is not powered by nuclear fusion, her calculation is wrong. And we know there are stars like the sun that go micronova or give superflares at set intervals. How does she explain that? Why would our sun not do that at any time? There is geological evidence this happened before in earth history. Apart from the "end of the world" myths.
I reckon geometry/trigonometry are the purest base for all math and science. All the answers are repeatable, predictable and non corruptible, a 2 dimensional triangle will always equal 180 degrees etc. Can't remember any of it now 🤦♂️ but I do remember learning to do it with a slide rule and a log book. Use it when I sometimes make a knife to determine the blade bevels. Thank universe for online calculators😁
1/3rd of the way in and I can say with conviction, as a guy who watches hours of TY/day learning, this is one of the best explanation video's i've ever seen.
I spent most of my school years thinking algebra and geometry were useless, then graduated to the real world and found out differently. I agree that being given real-world examples of math would have piqued my interest more.
First day of trigonometry for me was just as it should be. Our teacher took us out into a field and we measured a long straight line from the base of a tree, then the angle to the top from the end of our line. We used this to calculate the approximate height of the tree using a tangent. Always that maths teacher would show us or explain to us ways to use everything he taught us. He even used the example mentioned in another comment about calculating the length of timbers needed to make rafters for a house. The way he taught it maths was never useless and never boring. Mr Booth, dead now but definitely not forgotten.
It's really simple: math (just as anything else) can be taught well, or taught poorly. Traditionally, in good schools most of the sciences are taught by *doing*, and guided into understand how the result comes about. it's not straight pedagogy (teacher chanting rules from a book), but forcing the student to do and understand. Often straight math is difficult to teach that way beyond counting the result of adding 2 marbles to 3 marbles and getting 5 marbles. Common core in one sense is an attempt to make math more intuitively understood, but all too often it's either done badly, or the student's parents have heart failure because the teacher isn't sledgehammering the multiplication tables into their precious kid's brainz. It pisses me off, for example, that common core has such a bad name, that people invented it just to make kids stupid. No, it's the result of dozens of evolving methods, trials and seeing what actually DOES work BETTER whether the parents believe it or not. Sure some kids might do well in the older fashioned method, but in many cases they may result in not understanding math as well. Math appears to be most commonly taught starting with something easy to "do and understand" (playing with marbles), thru years of by-wrote, and not until you get to higher grades (or especially university) that the intuitive understandings of what was by wrote starts to appear. it helps to have a hobby that involves some stuff where STEM subjects help, and a good student starts to actually use the math. I was never a math wonk, but I knew several, and married one. I got taught it all, much of it pedagogically, but frankly I don't remember much of the detail and couldn't use it off the top of my head. But it's taken well enough for the sciences and technologies I work with to be intuitively understood, and if I really have to, I know where to refresh my memory of the detail. Much of education is NOT the detail, it's the method. To a degree, it doesn't matter what you're taught, only that you've developed a mental process to comprehend and learn. It's the intuitive understanding how things work, and the knowledge to know that there IS a math behind it, which you can cope with if you have to.
@@fromagefrizzbizz9377 They want obedient automatons, not critical thinkers, otherwise every governmnet official would be doing life, or on death row. A practical method would be to have classes attatched to industry, not only would the child see the theory in practical application, but gain a working knowledge of the industry itself, and be multi skilled as a result. They don't want that. That want you to spend a fortune on learning one vocation, as the debt inhibits social mobility and you are stable exploitable labor. Housing loans are another method of fascillitating this. We are nothing but commodities to be exploited and cast aside when no longer of use.They do not care about us in the least
You are far better than most scientists who try to explain the basics of their fields to the untrained. Clear, comprehensible and all done with a touch of humour. Please keep this up as long as you are able, it is a valuable contribution to science as it helps to inspire the next generation of scientists, as well as entertaining those who are just interested but work in other fields.
Love how answering such an innocent sounding question requires a century of scientific results from multiple fields. I never considered how we knew this, and your explanation was wonderful!
Also on your mention of the utility of trigonometry, I was a sonar tech in the US Navy on a submarine and we used trigonometry CONSTANTLY to determine how far away something was that we could only hear. One path of sound directly from the source and one of the ocean floor. That gives us two triangles, one being the right angle triangle with our boats distance from the bottom being one leg and the "bounced" sound path from the floor being the hypotonuse, and the other being the one made up of the two sound paths. We derive the hypotonuse and the two other angles of the right triangle and that gives us one leg of the other triangle and the two "near"angles and we use those to derive the length of the direct sound path to the target sound source. If we need to know the surface distance between our map location (as opposed to our position including depth) another right triangle with our newly discovered direct distance as hypotonuse and our depth below the surface gives us that. Sorry for the book, but know that i COULD have written much more, but i love whenever i can bring this up. :p
Thanks for showing us the thought process of a physicist! They don't teach this type of critical thinking at high school, which is why so many students such as myself struggled through physics in college. Would love to see more videos like this!
Wow, Dr. Becky! Great video. It got me going, and was following it doing actually the math. (I’m sorry, for me to completely understand I need to do the math thing). So, when I was figuring out the life of the Sun, we had these figures: E = 0.003 released of the fusion of H to He Mcore = 2.0e29 kg Speed of light =3e8 m/s Luminosity of the Sun = 3.8e26 kg • m^2 / s^3 (I converted the Jules to standard units) So, that gives us the following equation: Tsun = (0.003 • 2e29 kg • [3e8 m/s]^2) / 3.8e26 kg•m^2/s^3 And this gives me a funky result, which is: 1.421e17 s ~ 4.5e9 years, and not 10.5e9 years... what did I do wrong? (Sorry about the inconvenience! Awesome video!)
You are correct. You didn't do anything wrong. A slight mistake in the video I believe - the calculation gives how much time the Sun has left (rather than the total lifetime of the Sun). In addition, another assumption is made - the luminosity of the Sun won't vary greatly.
@@IndianHeathen1982 Was Dr. Becky calculating how much time the Sun has left; or how much time the Sun has left before it runs out of hydrogen (to fuse) in the core, and evolves off the main sequence?
Great video, I love the perspective you give. Far too many people just don't understand the "how we got to this answer" part. They either just accept the answer or deny it... based on nothing more than their own personal beliefs.
16:03 He was the brother of the german federal president Richard von Weizsäcker. Btw, I love this kind of video with the back of the envelope calculation while breaking it down to the actual measurements needed. Hope to see more of it!
4 года назад
I am actually kind of impressed about how you got his name right... given the post is edited, probably not the first time..., but still!
@ I only edited it to add the second part. But I have to admit that I was on his wikipedia page before writing the comment. Didn't remember if he was his brother or half-brother. So I saw his name there. And his last name is in the video, too :)
4 года назад
@@PaulPaulPaulson there was a famous blunder in german television, when the brother became federal president... i don't remember the details, to long ago, but if 'tagesschau' doesn't get a german presidents name right, everyone who does should be held in high regard.
1. That is Your best video to date - of those I have seen. 2. As a collegue of mine said years ago: Anything essential is just mental arithmatic. He was/is - in my view - correct. He (and I in all modesty) are economists; but the same principles apply in other sciences as well. Point being: If you get the ball park figure wrong, there is probably a basic principle, you are not taking into consideration - or you have oversimplified the problem. 3. Figures and estimates in astronomy and other siences is a weird zoo: Something is determined to an insane accuracy: The gravitational constant is determined to - I believe - 10 significant figures. With other factors you are jubilant to get a precision within +/- 50%. 4. Engineers and physicists normally look down their noses at economists - critisicing our accuracy. To this I normally reply: To the best of my knowledge: Physicists have only the vaguest ideas of what 80% of the universe actually is (black mass) - which is quite a big chunk of ingnorance. 5. Having said that: I contend, that economists repeatedly argue from misunderstanding of basic math - such as they differentiate functions that are not differentiable - heck, they are not even continious. If You look at the graphs for currency fluctuations and stock market it is abundantly clear, that the jerks do not have the remotest concept of logarithmic functions and growth (i.e. exponential functions) - and they claim to be experts: Which indeed is a claim, which in no way can lift the burden of proof - or even evoke a suspicion that they know what they are talking about.
This video completely changed the way I looked at things and even the way I solved problems. I remember so much of it from just one viewing despite never memorizing anything and having watched it months ago
Great video. A billion years here or there; that really gives you an idea of the scales involved when talking about the universe. I still remember how shocked I was when my physics professor worked out the derivation of Enstein's equation in class. It was so trivial - at least to a math major. It showed what insight there was to looking at the problem, and that something so profound was also so simple and elegant. (Too bad the same couldn't be said for quantum mechanics!) On a side note, I immediately thought of you while a friend was gushing on about the new Star Trek series focusing on Picard. One of the key plot points was a sudden supernova. Of all the questions that plot point rose, the one that stuck with me was, "Is there anyway a star can go supernova without someone noticing the process starting a long, long time ago? Maybe Dr. Becky is a fan and will discuss it some day." (Of course, the real answer is probably the writers know nothing about science, and not that there is some theoretical way for it to happen quickly.)
Yeah the efforts to try and understand high mass star formation, evolution and death is very difficult due to the short and extreme nature of such stars and the complex dynamic environments where they form. Astroseismology would in theory be a nice tool but in reality these stars are too dynamic with significant to extreme deviations from hydrostatic equilibrium that it isn't feasible. A more realistic mechanism would be if you could detect a sufficient amount of neutrinos from a star to determine what fusion reactions are going on in the core. The problem as you may know is that neutrinos are really hard to detect and plus that wouldn't tell you how far into each core reaction phase the star is. Of course as each phase gets smaller and smaller with Silicon fusion for example lasting only about a day that becomes less of a problem but it would probably be too late if things got to that point. Now for stars in our local universe the process of core collapse creates such an absurd amount of neutrinos that you should be able to detect a huge burst of them which within our local group at least could arrive before the star appears to visibly change outside. Thankfully core collapse supernovae candidate stars tend to be quite obvious before they occur and are relatively rare so it isn't a huge problem. Though we are astronomically speaking adjacent to a high mass star formation region which has played surprisingly significant effects on the course of life on Earth
I enjoy watching outtakes Becky at the end of each video. The information in the video was conveyed clearly and succinctly, all the necessary stuff without the fluff. I eagerly await the Dr Becky email every Thursday morning ( I live in Perth Western Australia)
Hardly a day goes by I don't use trig. Not just for my engineering job, but for stuff around the house. People really have no idea what it takes to answer some of those simple sounding questions! Another great vid, Becky!
I'm stunned people have the nerve to "dislike" a video such as this. Are they afraid of learning? Do they think the Earth is flat?? Thank you once again for enlightening my day. Many thanks to all the individuals who contributed to find out this specific question.
My 2 y.o. daughter often insists that I sing this to her: Twinkle, twinkle little star Scientists discovered what you are Giant ball of hydrogen gas* Creating energy by converting mass When protons in a nucleus are ensnared E equals M C squared *it's not just hydrogen and it's mostly a plasma, but hey, it had to rhyme!
Though I SUCK at math, and tbh I dropped out of high school, I typically understand these videos, this one broke me. I will have to watch it another time or two. I loved how she explained that it has taken many, many years and multiple geniuses to get to where we are.
I am 70 & I see a philosophical truth relevant to humans in this your one program! 👍🏼😊 You've shown an erudite explanation to derive the life of our sun. It is still an estimate, but it is the process that is the basis to build confidence into the estimate. This clearly shows the difference between science & religion, or reason & faith. Thanks again for the WAY you've presented.
Oo! Thanks! At this point in my experience with the English language, And the two mythologies, I have a pretty good intuition. But that’s a really helpful rule!
I SUCK at math but that fact has never stopped me from being fascinated by and loving all forms of science. This is an amazing video that I think should be shown to 7th and 8th graders in science class.
What I'd like to know: If the nuclear fusion is taking place in the centre 10%, That means a hot ball of 140,000 km diameter. The helium mass already produced over the last 4-5 billion years is heavier than the hydrogen, so will gravitate to the core, meaning there is a ball of helium at the core, of less than 10% of the total sun diameter; say 5%. Does that now mean that the H>He conversion is taking place in a boundary layer between the outer all-hydrogen surface and the all-helium core? Next question; if the change takes place at a fixed pressure/temperature crossing point, can the actual reaction-layer thickness be defined? Just curious to see how this one pans out! ...
Well the Sun is a sphere, and a long way away. We in earth only occupy a tiny sliver/angle cone of its space. We are very happy that we get the small amount. Any more or less and .life would be difficult.
It's cool to realize how little mass is converted into energy during fusion. That's what makes black holes so cool. When mass falls in and is then slowly radiated back out as Hawking radiation, it is a 100% conversion to energy. Since the HR output is inversely proportional to the size of the hole, the best energy source is a very small hole to which you feed matter at the same rate it's lost through HR. Result: a perfect mass to energy reactor.
To me, this calculation is more of fudging numbers with lots of unfounded assumptions, but that's how science works these days, so really good to know. Thanks Becky!!!
You know, they didn't have radar in the 18th and 19th century when they first accurately measured the distance to the Sun. Maybe you should have touched on the method they used, it also involved trigonometry. 😉
"The whole core of the sun was a hot dense place, and then four point five billion years ago nuclear fusion started, wait!" That's incredible! :O :D looks like you thought it up right there at the spot, did you?
Not for back-of-the-envelope. Hydrogen is like 73%, helium 25%, so like only 2% other stuff. The main inaccuracy in her method is that the Sun's fusion isn't constant, but changes as the Sun moves along the main sequence. That's why it's off by about 10%.
Someone else did, and she forgot to mention (i guess not to confuse the unsuspecting public), that there are some major well known and unexplained problems with the suns nuclear fusion model...but, i am sure she can answer these questions. ruclips.net/video/ezHBuvDxihE/видео.html Because, if the sun is not powered by nuclear fusion, her calculation is wrong. And we know there are stars like the sun that go micronova or give superflares at set intervals. How does she explain that? Why would our sun not do that at any time? There is geological evidence this happened before in earth history. Apart from the "end of the world" myths.
You can see the crescent of Venus when looking through a telescope. When it is "half moon", then you know the angle to the sun is 90°. In fact, you don't even have to wait for that special 90° position. You can always calculate the angle to the Sun by measuring the crescent. en.wikipedia.org/wiki/Phases_of_Venus
@@KohuGaly I guess it's easier to precisely measure the 90° phase though (and to measure such an important distance as Earth-Sun distance, you want accuracy). A crescent is not as trivial of a shape as a straight line splitting a disk in half.
@@KohuGaly Well that and we've been observing Venus for quite some time now and know when either of the greatest elongation points will be which is when it'll be a half Venus.
Helium being the most inert chemically and one of the lightest physically it was very hard to find it on earth for a very long time. Helium is the only gas molecule that can escape the gravity of earth and reach the space if left in open (if I am not wrong).
@@Bouzsi "The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the chromosphere of the Sun. The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India" Wikipedia
Great job. I have only found your RUclips channel a month ago and still working on all your older video. Enjoying every one. You make astronomy enjoyable and lets my think about space. Hard to find other people in the real world that wants to talk about these topics. Hope high school science teachers use your videos.
wow Becky it maybe impressive to know how long it took to find that number by so many people.over many many years..but whats more impressive is how you managed to reel all that off from memory in 23 minutes... i,m blown away by you not the scientists before you. And whats more is to teach us in such a simple way that we can understand...youve found yourself a new fan
Dr. Becky, I have a problem. A looping constant. Since you have sorta gone American could you please say "beer can" with your best Britsh form? And when you say beer can" does it sound like 'bacon' with a Jamaican accent? It's not very technical, buuuuuT, 😊 with your help I could cross this one off the looping bucket list. I liked the video. Therefore the cosmological constant can be interpreted as arising from a form of energy which has a negative pressure, equal in magnitude to its (positive) Energy density. Dismantaling the principles of identity. No idea what this means, it just sounded cool 😎 like your British, and your education, and talents - superb Suprano French, and Piano and Singing! And even I think I saw some ballet form once, certainly some dance. So. . . Did you say that our light spectrum is entirely helium based or neutrino based or hydrogen based? And or a mix with our predominate hydrogen atmosphere, oxygen, nitrogen. If it did burn most of the hydrogen as light process and then dark space and then reacting with our hydrogen to give light again. . . That would be like blinking, huh? 🙂😌🙂 And some Twinkling 😊 And are Fraunhauffer lines other elements from hotter, (more gravity) Stars? I don't like the whole electromagnetic plasma either, buuuuuT 😊if there is a charged particle it might bend in our atmosphere, (magnetic field) Like the ionic spectrometer? Which would make sun rays straight lines maybe. Positive attraction. If the sun is giving off helium and space is full of helium, giving us an atmospheric pressure, may be contributing to gravity and sound pressure, then maybe space is like a fluid dynamic and light is about constant pressure given off by the sun, that it has a constant tone. Iff there was less pressure would we have less light? I have no idea why some days the light is warm and some days it's not. Maybe it's the neutrinos moving through particles nudging them, (pressure variable) Giving temperature. I actually have no idea what I am talking about, it's probably some simple attraction that is neither electromagnetic or chemical. I don't think I will ever figure it out. I bet you will though. Cheers! Please Pray For China. 💙 👀 Thanks for the videos. 💜 👅 And fluffy sweaters. i'm over tired 😴 I like what you did with the office.
Thank you for explain it like this. I am 45 and no one has explain it so it made any sense. You give the right amount of information and just don’t say “we just know how ……”
Brilliant! We have just blasted at light speed through an entire year of Physics, to find out how much time left our Sun has, from Dr Becky! Awesome! And on the topic of Spectrometry, I highly recommend episode 7 of "Cosmos: A Spacetime Odyssey", entitled, "The Clean Room", which talks about how Uranium decays to Lead, as well as the heroic work of Clare Patterson to eliminate lead poisoning in the U.S.
Why do I cry sometimes when I experience new intelligence/phenomena specially in astronomy and astrophysics... It really moves me. Like just now when I watched what you linked about helioseismology and she played what the sun would sound like, I cried! And the other day when Perseverance had sent back audio from mars, I cried a lot!
Thank you for pointing out how much human effort went into assembling what we now regard as commonplace knowledge. I believe all science courses should begin with an overview like the one you've presented.
I think I was rather fortunate, because in primary school, there was one teacher who was rather passionate about science and he passed on snippets in chemistry and physics to all the adoring sponges in his class. It was he who kind of inspired me (and others) to pursue the field of science _AND_ the ideas in evolution (!) in later life. I often feel that many of the concepts in science related to our day-to-day existence ("Observe and Measure") should be taught. It's not difficult at all (well, it wasn't to me anyway :0) I'm a retired scientist now (forensic entomology ~ though I also did degrees in foundational science and also computer science - for the fun of it really! I'm still an amateur astronomer and enjoy just looking at the heavens!! Thanks Dr Becky once again!
Wow, dr becky for you to explain the universe, you are the next Newton of today, incredible clarity and memory to rattle the numbers so correctly, please keep explaining away
إذا افترضت أن للضوء قصة أو حكاية يمكن أن تروى .. فإنني أعتقد أنك يا دكتورة من القلائل القادرين على سرد تفاصيل رحلة مذهلة ... و خصوصا تلك العلاقة التوأمية مع الالكترون .. أو في أي حقل أنت ملكة الاختيار .. ان حدث هذا سيكون أمرا رائعا في اعتقادي بالرغم من ضعفي و قلة خبرتي في اللغة الانكليزية و التي أعمل على اغنائها 💚
I remember the first time EMC2 came up in a physics class; talking about subatomic particles, putting a few calculations on the board, cancel a few terms here, substitute this over there. He played it slowly and when we all realised where it was going was, it like the DiCaprio pointing meme
becky thanks for your great science videos. Thanks to your very understandable pronunciation, I can learn English in addition to the exciting astrophysics. its charming and authentic charisma makes it one of the best additions to reading a book or sitting in an auditorium and listening to science!
Seismology and trigonometry: also from greek! Excellent show. I plan to show it today to my son to help the understanding of acquisition of knowledge for his IB TOK. Thanks again.
At the beginning of the video, you asked what the most famous physics equation is. I honestly never learnt E=mc2. I answered, Speed equals distance over time. And then later on you totally said the thing :D I love trig. Was amazing at it. I went to a very disadvantaged school. We didn't have physics. Too bad I didn't have an education to be able to get a good job to be able to earn money to go to subscribe to Brilliant. You're a great teacher Dr. Becky :D P. S., I was the only one in my school that knew how to transpose an equation. Too late now though :( I guess I'll leave it all to you :) The only thing I learnt in 6 years of high school in "science" was the act of peristalsis haha. I honestly am freaked out by human anatomy. Give me astrophysics and cosmology any day! Best wishes.
Gotta say that that was some brillant deductive reasoning with undisputable facts thrown in Dr. Becky. Now I know a lot more about the age of the Sun & how long it has to live, give or take a few billion years.................👍👍🔴🔴👍👍
What a fantastic explanation of such a relatively simple sounding question. It makes me appreciate the bigger picture and the process of how the suns age was calculated. Plus you make it understandable to a degree and present it very well. Dr. Becky, you have a long time subscriber. Keep up the great work
18:55 - "I can safely say that nobody understands quantum mechanics.” Richard Feynman (1965). (Brilliant overview of all the incredible research across so many different scientific fields!)
Well done Dr Becky! That was an amazing video! As others mentioned in the comments, be explaining the scientific steps in which scientific facts take form one can understand that science is not a collection of data but a way of thinking! Truly great video!
There is one thing unclear to me. When you calculate the mass of the sun, it is the actual mass of the sun, not its initial mass. So, why it is not the rest of the sun life that is calculated instead of its whole lifespan ? Bravo for your videos. Always captivating.
Great video! Never seen such a detailed explanation of Sun's remaining age. Thank you. Also, I saw on another channel some time back that although Sun will live for another 5 billion years, Earth will not remain habitable for more than few hundred million years or so, due to increase in Sun's luminosity. It would be amazing if you can cover that in one of your future videos.
Thank you @Dr. Becky! I recently discovered your channel and am enjoying all your videos. I’m sending this to my mom even though it will probably bother her to think about...it also seems to bother her when I talk about how in less than 100 years she and I will almost certainly be dead...so the ~5 billion years of sun life left should not bother her or me...great video!
I love it. I am 70 years old. Sol will outlast me by about 5 billion years. I might get 2 or 3 more suntans. In 100 years who will care? Thanks, Doctor, for drawing my attention to my lifespan, in relation to the Vast Universe. Love your work.
Can we add some more flags with a follow up? :) thank you! 1: Luminosity (Solar irradiance or TSI for climate data formulas): -Does this account for all particles and matter states? (thinking a light bulb that's turned off still has mass, or about x-rays given off other particles/waves etc) -If we use Luminosity again is this answering why the corona is far hotter than the underlying layers and how that would explain that it's purely burning itself for fuel? 2: E=mc2 ( what is mass if it's matter, what is energy? if we don't understand how gravity works and only describe it by describing its effects or itself to describe it i'm sure we understand mass or if we're correct in the age of the sun or life span. 3: Gravity/speed of light limitations Even with an 8min delay for light if gravity communicates with the earth by way of a single directional force of acceleration at that latency we'd never achieve stable orbits that remain 'constant" if there were ANY other variables introduced. We just added dark matter and black holes, we never solved the problem. Currently the gravity formula/model fails to account for the rotation distance/speed fall off of galaxies which means we don't have that calculation correct or the speed at which information can travel and why. okay 21 more mins to go!! weee
A little side note on calculating the circumference of Earth's orbit. It's actually much more circular than most people think, because it comes extremely close to matching a circle whose center is offset from the Sun by the eccentricity, ea, where e = 0.016, and a = 1 AU. Its fractional deviation from the "offset circle" of radius a, is on the order of e². Note that this remark is meant only as a little extra information in support of your (quite excellent!) presentation here. But wait - as you go through the back-of-envelope calculation of the Sun's age, you have 15 Ty. Then using the 10% of its mass that is fusing, takes you down to 1.5 Ty. Then you fold in the fact that only 0.3% of the hydrogen mass gets converted to energy. Shouldn't that bring the lifespan down by a factor of x0.003, to 4.5 Gy, not 10.5 Gy? So was that 99.7% figure supposed to be 99.3%, leaving 0.7% mass conversion? Which would have led to the stated lifespan of 10.5 Gy? Or is there something I've missed here? At 6m 43s, in your final formula for M[Sun], "365.25 days" in the denominator, should be squared. 16min: "Gamow" is pronounced, "GAMM-off." 20m 40s: ²³⁸U decays to ²¹⁰Pb, not ²⁰⁷Pb. This follows from the fact that the decay chain is entirely α and β decays; the former always reduce the atomic mass number, A, by 4, while the latter always leave A unchanged. So the final A value must differ from (be lower than) the starting value by a multiple of 4. Overall, this was a totally splendid presentation. I think it's the best, most concise, and solidly factual exposition I've seen or heard, in answer to this question. Kudos! Fred
This video is pure science and I love it! She takes a huge subject and breaks it into individual provable parts which is by far the most valuable skill when it come to scientific communication. I would take any class taught by her!
8:30 Trigonometry was my great nemesis in my school years, I never had problems with numbers at school, in fact math was always easy for me except for trigonometry, no matter how hard I studied and studied, I never fully understood it
This is a point that is often ignored by most "science popularizers" (and, unfortunately, many science teachers): that science is a process, not a list of facts to be memorized. Explaining how we know an answer is at least as important as answering a question. Kudos, Dr. Becky.
Perhaps, if people knew there is no truth in science, nothing is ever settled, and no theory has ever been proven to be the "Truth", then perhaps the political purposes of the 4th Reich could be separated from humanity's desire to elevate itself above the status of biological robots serving any world order.
Yep. Dr. Becky rules!
Not as important, knowing the meaning behind it is totally the point. I went through my homework when I was young, at a lower level, grabbing books of a higher level to be able to understand things. If not, I had a hard time memorizing things or simply "taking it for granted". It took me hours more, but am glad I did it. As Feynman once said "I learned early the difference between knowing the name of something and knowing something. "
Yes, but simplistic answers allow the priesthood to maintain their monopoly as intermediaries between Science and the unwashed masses. _"If I omit the most basic questions about how humankind figured this out, then I'll look like a genius, and it'll generate an assload of obsequious flattery in the comments section!"_
Except, she forgot to mention (i guess not to confuse the unsuspecting public), that there are some major well known and unexplained problems with the suns nuclear fusion model...but, i am sure she can answer these questions.
ruclips.net/video/ezHBuvDxihE/видео.html
Because, if the sun is not powered by nuclear fusion, her calculation is wrong.
And we know there are stars like the sun that go micronova or give superflares at set intervals. How does she explain that? Why would our sun not do that at any time? There is geological evidence this happened before in earth history. Apart from the "end of the world" myths.
Trigonometry is used in carpentry to calculate rafter lengths. Yay Trig!
Yay Trig!
So, trig for measuring a birdsmouth. 😉
Dahhh, scribe to fit, beat to match. 😉
3/4/5 FTW!
I reckon geometry/trigonometry are the purest base for all math and science. All the answers are repeatable, predictable and non corruptible, a 2 dimensional triangle will always equal 180 degrees etc. Can't remember any of it now 🤦♂️ but I do remember learning to do it with a slide rule and a log book. Use it when I sometimes make a knife to determine the blade bevels. Thank universe for online calculators😁
I always heard about the number, but never got how we got there. Thanks, Dr. B.
1/3rd of the way in and I can say with conviction, as a guy who watches hours of TY/day learning, this is one of the best explanation video's i've ever seen.
This is what kids need to hear in Middle School to get them excited in math! Kids are always told to do math, but never shown it applied.
I spent most of my school years thinking algebra and geometry were useless, then graduated to the real world and found out differently. I agree that being given real-world examples of math would have piqued my interest more.
First day of trigonometry for me was just as it should be. Our teacher took us out into a field and we measured a long straight line from the base of a tree, then the angle to the top from the end of our line. We used this to calculate the approximate height of the tree using a tangent. Always that maths teacher would show us or explain to us ways to use everything he taught us. He even used the example mentioned in another comment about calculating the length of timbers needed to make rafters for a house. The way he taught it maths was never useless and never boring.
Mr Booth, dead now but definitely not forgotten.
I used it for figuring out how to make a tire stick on a race track :P
It's really simple: math (just as anything else) can be taught well, or taught poorly. Traditionally, in good schools most of the sciences are taught by *doing*, and guided into understand how the result comes about. it's not straight pedagogy (teacher chanting rules from a book), but forcing the student to do and understand. Often straight math is difficult to teach that way beyond counting the result of adding 2 marbles to 3 marbles and getting 5 marbles. Common core in one sense is an attempt to make math more intuitively understood, but all too often it's either done badly, or the student's parents have heart failure because the teacher isn't sledgehammering the multiplication tables into their precious kid's brainz.
It pisses me off, for example, that common core has such a bad name, that people invented it just to make kids stupid. No, it's the result of dozens of evolving methods, trials and seeing what actually DOES work BETTER whether the parents believe it or not. Sure some kids might do well in the older fashioned method, but in many cases they may result in not understanding math as well.
Math appears to be most commonly taught starting with something easy to "do and understand" (playing with marbles), thru years of by-wrote, and not until you get to higher grades (or especially university) that the intuitive understandings of what was by wrote starts to appear. it helps to have a hobby that involves some stuff where STEM subjects help, and a good student starts to actually use the math.
I was never a math wonk, but I knew several, and married one. I got taught it all, much of it pedagogically, but frankly I don't remember much of the detail and couldn't use it off the top of my head. But it's taken well enough for the sciences and technologies I work with to be intuitively understood, and if I really have to, I know where to refresh my memory of the detail.
Much of education is NOT the detail, it's the method. To a degree, it doesn't matter what you're taught, only that you've developed a mental process to comprehend and learn.
It's the intuitive understanding how things work, and the knowledge to know that there IS a math behind it, which you can cope with if you have to.
@@fromagefrizzbizz9377 They want obedient automatons, not critical thinkers, otherwise every governmnet official would be doing life, or on death row.
A practical method would be to have classes attatched to industry, not only would the child see the theory in practical application, but gain a working knowledge of the industry itself, and be multi skilled as a result.
They don't want that. That want you to spend a fortune on learning one vocation, as the debt inhibits social mobility and you are stable exploitable labor. Housing loans are another method of fascillitating this.
We are nothing but commodities to be exploited and cast aside when no longer of use.They do not care about us in the least
You are far better than most scientists who try to explain the basics of their fields to the untrained. Clear, comprehensible and all done with a touch of humour. Please keep this up as long as you are able, it is a valuable contribution to science as it helps to inspire the next generation of scientists, as well as entertaining those who are just interested but work in other fields.
Love how answering such an innocent sounding question requires a century of scientific results from multiple fields. I never considered how we knew this, and your explanation was wonderful!
It's a great day when a new Dr. Becky video is released! :D
Sebastian Farkas love watching her
Really amazing format, explaining the bigger picture, and then filling in the gaps makes learning a breeze. Please continue this format.
Also on your mention of the utility of trigonometry, I was a sonar tech in the US Navy on a submarine and we used trigonometry CONSTANTLY to determine how far away something was that we could only hear. One path of sound directly from the source and one of the ocean floor. That gives us two triangles, one being the right angle triangle with our boats distance from the bottom being one leg and the "bounced" sound path from the floor being the hypotonuse, and the other being the one made up of the two sound paths. We derive the hypotonuse and the two other angles of the right triangle and that gives us one leg of the other triangle and the two "near"angles and we use those to derive the length of the direct sound path to the target sound source. If we need to know the surface distance between our map location (as opposed to our position including depth) another right triangle with our newly discovered direct distance as hypotonuse and our depth below the surface gives us that. Sorry for the book, but know that i COULD have written much more, but i love whenever i can bring this up. :p
Absolutely great job with the "how we know" question. There needs to be much more of this in science education. Thanks.
I so love how you break it down, then explain it so understandably. Fun learning!
Thanks for showing us the thought process of a physicist! They don't teach this type of critical thinking at high school, which is why so many students such as myself struggled through physics in college. Would love to see more videos like this!
Wow, Dr. Becky! Great video. It got me going, and was following it doing actually the math. (I’m sorry, for me to completely understand I need to do the math thing). So, when I was figuring out the life of the Sun, we had these figures:
E = 0.003 released of the fusion of H to He
Mcore = 2.0e29 kg
Speed of light =3e8 m/s
Luminosity of the Sun = 3.8e26 kg • m^2 / s^3 (I converted the Jules to standard units)
So, that gives us the following equation:
Tsun = (0.003 • 2e29 kg • [3e8 m/s]^2) / 3.8e26 kg•m^2/s^3
And this gives me a funky result, which is: 1.421e17 s ~ 4.5e9 years, and not 10.5e9 years... what did I do wrong? (Sorry about the inconvenience! Awesome video!)
You are correct. You didn't do anything wrong. A slight mistake in the video I believe - the calculation gives how much time the Sun has left (rather than the total lifetime of the Sun). In addition, another assumption is made - the luminosity of the Sun won't vary greatly.
@@IndianHeathen1982 Was Dr. Becky calculating how much time the Sun has left; or how much time the Sun has left before it runs out of hydrogen (to fuse) in the core, and evolves off the main sequence?
I see a trend in Dr. Becky videos. She explains how exactly we know the stuff we know, and that isn't seen in many people. Hats off
Thanks 🤗 I think it’s so important to do that! Especially since it helps people to remember what we know as well 👍
Great video, I love the perspective you give. Far too many people just don't understand the "how we got to this answer" part. They either just accept the answer or deny it... based on nothing more than their own personal beliefs.
I love how you explain things, and you make it easy to understand even if we don't have degrees in science. You make learning fun.
16:03 He was the brother of the german federal president Richard von Weizsäcker.
Btw, I love this kind of video with the back of the envelope calculation while breaking it down to the actual measurements needed. Hope to see more of it!
I am actually kind of impressed about how you got his name right... given the post is edited, probably not the first time..., but still!
@ I only edited it to add the second part. But I have to admit that I was on his wikipedia page before writing the comment. Didn't remember if he was his brother or half-brother. So I saw his name there. And his last name is in the video, too :)
@@PaulPaulPaulson there was a famous blunder in german television, when the brother became federal president... i don't remember the details, to long ago, but if 'tagesschau' doesn't get a german presidents name right, everyone who does should be held in high regard.
1. That is Your best video to date - of those I have seen.
2. As a collegue of mine said years ago: Anything essential is just mental arithmatic.
He was/is - in my view - correct. He (and I in all modesty) are economists; but the same principles apply in other sciences as well.
Point being: If you get the ball park figure wrong, there is probably a basic principle, you are not taking into consideration - or you have oversimplified the problem.
3. Figures and estimates in astronomy and other siences is a weird zoo: Something is determined to an insane accuracy: The gravitational constant is determined to - I believe - 10 significant figures. With other factors you are jubilant to get a precision within +/- 50%.
4. Engineers and physicists normally look down their noses at economists - critisicing our accuracy. To this I normally reply: To the best of my knowledge: Physicists have only the vaguest ideas of what 80% of the universe actually is (black mass) - which is quite a big chunk of ingnorance.
5. Having said that: I contend, that economists repeatedly argue from misunderstanding of basic math - such as they differentiate functions that are not differentiable - heck, they are not even continious. If You look at the graphs for currency fluctuations and stock market it is abundantly clear, that the jerks do not have the remotest concept of logarithmic functions and growth (i.e. exponential functions) - and they claim to be experts: Which indeed is a claim, which in no way can lift the burden of proof - or even evoke a suspicion that they know what they are talking about.
This video completely changed the way I looked at things and even the way I solved problems. I remember so much of it from just one viewing despite never memorizing anything and having watched it months ago
Great video. A billion years here or there; that really gives you an idea of the scales involved when talking about the universe.
I still remember how shocked I was when my physics professor worked out the derivation of Enstein's equation in class. It was so trivial - at least to a math major. It showed what insight there was to looking at the problem, and that something so profound was also so simple and elegant. (Too bad the same couldn't be said for quantum mechanics!)
On a side note, I immediately thought of you while a friend was gushing on about the new Star Trek series focusing on Picard. One of the key plot points was a sudden supernova. Of all the questions that plot point rose, the one that stuck with me was, "Is there anyway a star can go supernova without someone noticing the process starting a long, long time ago? Maybe Dr. Becky is a fan and will discuss it some day." (Of course, the real answer is probably the writers know nothing about science, and not that there is some theoretical way for it to happen quickly.)
Yeah the efforts to try and understand high mass star formation, evolution and death is very difficult due to the short and extreme nature of such stars and the complex dynamic environments where they form.
Astroseismology would in theory be a nice tool but in reality these stars are too dynamic with significant to extreme deviations from hydrostatic equilibrium that it isn't feasible. A more realistic mechanism would be if you could detect a sufficient amount of neutrinos from a star to determine what fusion reactions are going on in the core. The problem as you may know is that neutrinos are really hard to detect and plus that wouldn't tell you how far into each core reaction phase the star is. Of course as each phase gets smaller and smaller with Silicon fusion for example lasting only about a day that becomes less of a problem but it would probably be too late if things got to that point.
Now for stars in our local universe the process of core collapse creates such an absurd amount of neutrinos that you should be able to detect a huge burst of them which within our local group at least could arrive before the star appears to visibly change outside. Thankfully core collapse supernovae candidate stars tend to be quite obvious before they occur and are relatively rare so it isn't a huge problem.
Though we are astronomically speaking adjacent to a high mass star formation region which has played surprisingly significant effects on the course of life on Earth
You need to be on the BBC The Sky At Night as a presenter 👍🇬🇧
Yoda Matrix is the monocle optional?
When Maggie Aderin-Pocock first presented the TSaN she was so enthusiastic and knowledgeable,but she did sound like a schoolgirl on helium.
Unfortunately it's produced by the BBC, she'd need to swap genders before that ever happened.... :/
Sorry, too White for woke left...
But the Sun is visible during the daytime.
I enjoy watching outtakes Becky at the end of each video. The information in the video was conveyed clearly and succinctly, all the necessary stuff without the fluff. I eagerly await the Dr Becky email every Thursday morning ( I live in Perth Western Australia)
Hardly a day goes by I don't use trig. Not just for my engineering job, but for stuff around the house. People really have no idea what it takes to answer some of those simple sounding questions! Another great vid, Becky!
It's very humbling to make oneself clear how much we really are standing on the shoulders of giants.
LOVE this video!! I knew the math, but knowing how they came up with the numbers is enlightening. Yay, Dr Becky!
The way you present and teach the matter is very refreasing for me. You have that gift in you.
I'm stunned people have the nerve to "dislike" a video such as this. Are they afraid of learning? Do they think the Earth is flat??
Thank you once again for enlightening my day. Many thanks to all the individuals who contributed to find out this specific question.
My 2 y.o. daughter often insists that I sing this to her:
Twinkle, twinkle little star
Scientists discovered what you are
Giant ball of hydrogen gas*
Creating energy by converting mass
When protons in a nucleus are ensnared
E equals M C squared
*it's not just hydrogen and it's mostly a plasma, but hey, it had to rhyme!
I am speechless😑
i had a very hard time believing this
cus my three year old sis doesn't speak full words yet, let alone asking to me to sing
Thank you!
I love knowing what, but it makes it so much better to also know the why!
Though I SUCK at math, and tbh I dropped out of high school, I typically understand these videos, this one broke me. I will have to watch it another time or two. I loved how she explained that it has taken many, many years and multiple geniuses to get to where we are.
I am 70 & I see a philosophical truth relevant to humans in this your one program! 👍🏼😊
You've shown an erudite explanation to derive the life of our sun. It is still an estimate, but it is the process that is the basis to build confidence into the estimate.
This clearly shows the difference between science & religion, or reason & faith.
Thanks again for the WAY you've presented.
You're my favorite doctor, Doctor Becky!
I absolutely love these explanations!
P.S. Short tip: "~os" = most likely greek, "~us" = most likely roman.
Oo! Thanks! At this point in my experience with the English language, And the two mythologies, I have a pretty good intuition. But that’s a really helpful rule!
That's good for Helios, but _counter-example:_ Mount Olympus is the highest mountain in Greece.
@@YodaWhat In greek its name is Όλυμπος , Olympos ;)
@@SigmarSich Yes, but that is _in Greek._ @Hope Gold, speaking English, could be misled by your general rule... at least when applying it to English.
@@YodaWhat it's still os
I SUCK at math but that fact has never stopped me from being fascinated by and loving all forms of science. This is an amazing video that I think should be shown to 7th and 8th graders in science class.
This video is gold. That's how things should be explained!
What I'd like to know:
If the nuclear fusion is taking place in the centre 10%, That means a hot ball of 140,000 km diameter. The helium mass already produced over the last 4-5 billion years is heavier than the hydrogen, so will gravitate to the core, meaning there is a ball of helium at the core, of less than 10% of the total sun diameter; say 5%.
Does that now mean that the H>He conversion is taking place in a boundary layer between the outer all-hydrogen surface and the all-helium core?
Next question; if the change takes place at a fixed pressure/temperature crossing point, can the actual reaction-layer thickness be defined?
Just curious to see how this one pans out! ...
What’s astonishing is the small fraction of energy we receive from the total output of the 🌞
Well the Sun is a sphere, and a long way away. We in earth only occupy a tiny sliver/angle cone of its space. We are very happy that we get the small amount. Any more or less and .life would be difficult.
It's cool to realize how little mass is converted into energy during fusion. That's what makes black holes so cool. When mass falls in and is then slowly radiated back out as Hawking radiation, it is a 100% conversion to energy. Since the HR output is inversely proportional to the size of the hole, the best energy source is a very small hole to which you feed matter at the same rate it's lost through HR. Result: a perfect mass to energy reactor.
Miss Becky, or should I say Dr Becky, you are truly amazing.Your video on the life of the sun is just amazing ! ! ! Well done.
To me, this calculation is more of fudging numbers with lots of unfounded assumptions, but that's how science works these days, so really good to know. Thanks Becky!!!
You know, they didn't have radar in the 18th and 19th century when they first accurately measured the distance to the Sun. Maybe you should have touched on the method they used, it also involved trigonometry. 😉
18th and 19th century? Or 2300 BC?
"The whole core of the sun was a hot dense place, and then four point five billion years ago nuclear fusion started, wait!"
That's incredible! :O :D looks like you thought it up right there at the spot, did you?
I did! I was so proud haha
@@DrBecky Now we need the rest of the song :D
Not for back-of-the-envelope. Hydrogen is like 73%, helium 25%, so like only 2% other stuff.
The main inaccuracy in her method is that the Sun's fusion isn't constant, but changes as the Sun moves along the main sequence. That's why it's off by about 10%.
Someone else did, and she forgot to mention (i guess not to confuse the unsuspecting public), that there are some major well known and unexplained problems with the suns nuclear fusion model...but, i am sure she can answer these questions.
ruclips.net/video/ezHBuvDxihE/видео.html
Because, if the sun is not powered by nuclear fusion, her calculation is wrong.
And we know there are stars like the sun that go micronova or give superflares at set intervals. How does she explain that? Why would our sun not do that at any time? There is geological evidence this happened before in earth history. Apart from the "end of the world" myths.
@@gammaraygem You are clueless like a flattard.
This VDO is a lot more meaningful to me as it combined of those explanations, knowledge AND the Sun behaviour.
You're my new astrophysics guru. I can watch your presentations in their entirety and not be bored for a second. What is this power you hold over me?
7:59 What's a good way to determine when Venus, the Earth and the Sun form a right-angled triangle like that, though?
You can see the crescent of Venus when looking through a telescope. When it is "half moon", then you know the angle to the sun is 90°. In fact, you don't even have to wait for that special 90° position. You can always calculate the angle to the Sun by measuring the crescent.
en.wikipedia.org/wiki/Phases_of_Venus
@@KohuGaly I guess it's easier to precisely measure the 90° phase though (and to measure such an important distance as Earth-Sun distance, you want accuracy). A crescent is not as trivial of a shape as a straight line splitting a disk in half.
@@KohuGaly Well that and we've been observing Venus for quite some time now and know when either of the greatest elongation points will be which is when it'll be a half Venus.
It’s called the “greatest elongation” of Venus - it’s the point at which it’s furthest from the sun in the sky
Always amazed that helium was discovered in the Sun before on Earth!
Helium being the most inert chemically and one of the lightest physically it was very hard to find it on earth for a very long time. Helium is the only gas molecule that can escape the gravity of earth and reach the space if left in open (if I am not wrong).
@@tdhanasekaran3536 Well, hydrogen, too - if doest active with something the way up.
@@larrybeckham6652 *shakes head* uhh what?
@@Bouzsi "The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the chromosphere of the Sun. The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India" Wikipedia
Great job. I have only found your RUclips channel a month ago and still working on all your older video. Enjoying every one. You make astronomy enjoyable and lets my think about space. Hard to find other people in the real world that wants to talk about these topics. Hope high school science teachers use your videos.
wow Becky it maybe impressive to know how long it took to find that number by so many people.over many many years..but whats more impressive is how you managed to reel all that off from memory in 23 minutes... i,m blown away by you not the scientists before you. And whats more is to teach us in such a simple way that we can understand...youve found yourself a new fan
This Yank thinks you rock! Thanks so much for these.
Blimey!
Becky, have you watched the "Timelapse Of The Future" video by Melody Sheep on RUclips? it's a fascinating insight on the future of the universe.
Awesome video. Simply mind-blowing!
Trust me people, you need to see this!
Chris - yes, that’s a very humbling video!
Highly recommend watching it on large screen with a decent sound system!
Your most excellent excellent & elementary video on your whole channel. Very enjoyable watch
You make it so simple to understand and no assumptions
"Between astrophysicists and friends"
Great title for a podcast....
"I've gone American"
Well... once you go American....... ;)
A billion years here, a billion years there, soon you're talking about a lot of time.
... you become obese, get diabetes and go bankrupt because of healthcare costs?
@@turkosicsaba yeah, but we have guns so we can then blow our brains out after all that happens.
Dr. Becky, I have a problem. A looping constant. Since you have sorta gone American could you please say "beer can" with your best Britsh form? And when you say beer can" does it sound like 'bacon' with a Jamaican accent? It's not very technical, buuuuuT, 😊 with your help I could cross this one off the looping bucket list.
I liked the video.
Therefore the cosmological constant can be interpreted as arising from a form of energy which has a negative pressure, equal in magnitude to its (positive) Energy density.
Dismantaling the principles of identity.
No idea what this means, it just sounded cool 😎 like your British, and your education, and talents - superb Suprano French, and Piano and Singing! And even I think I saw some ballet form once, certainly some dance.
So. . .
Did you say that our light spectrum is entirely helium based or neutrino based or hydrogen based? And or a mix with our predominate hydrogen atmosphere, oxygen, nitrogen.
If it did burn most of the hydrogen as light process and then dark space and then reacting with our hydrogen to give light again. . . That would be like blinking, huh? 🙂😌🙂 And some Twinkling 😊
And are Fraunhauffer lines other elements from hotter, (more gravity) Stars?
I don't like the whole electromagnetic plasma either, buuuuuT 😊if there is a charged particle it might bend in our atmosphere, (magnetic field) Like the ionic spectrometer? Which would make sun rays straight lines maybe. Positive attraction.
If the sun is giving off helium and space is full of helium, giving us an atmospheric pressure, may be contributing to gravity and sound pressure, then maybe space is like a fluid dynamic and light is about constant pressure given off by the sun, that it has a constant tone. Iff there was less pressure would we have less light? I have no idea why some days the light is warm and some days it's not. Maybe it's the neutrinos moving through particles nudging them, (pressure variable) Giving temperature.
I actually have no idea what I am talking about, it's probably some simple attraction that is neither electromagnetic or chemical. I don't think I will ever figure it out. I bet you will though. Cheers!
Please Pray For China. 💙 👀
Thanks for the videos. 💜 👅 And fluffy sweaters.
i'm over tired 😴 I like what you did with the office.
@@nousernamejoshua1556 that's "dr Becky" not "ms"
I find it sooooo impressive that there are people who get to those solutions!
One of the greatest science videos I've seen on RUclips ever. Period.
Wow! High praise - thanks!
Thank you for explain it like this. I am 45 and no one has explain it so it made any sense. You give the right amount of information and just don’t say “we just know how ……”
Brilliant! We have just blasted at light speed through an entire year of Physics, to find out how much time left our Sun has, from Dr Becky! Awesome! And on the topic of Spectrometry, I highly recommend episode 7 of "Cosmos: A Spacetime Odyssey", entitled, "The Clean Room", which talks about how Uranium decays to Lead, as well as the heroic work of Clare Patterson to eliminate lead poisoning in the U.S.
I love the way you explain it is so clear. Two thumbs ups Dr.
wow, I was so amazed by Becky's best methods of teaching. Thanks Becky, Keep it up!
Why do I cry sometimes when I experience new intelligence/phenomena specially in astronomy and astrophysics... It really moves me. Like just now when I watched what you linked about helioseismology and she played what the sun would sound like, I cried! And the other day when Perseverance had sent back audio from mars, I cried a lot!
They should play this video in high school science class. What an amazing presentation!
Thank you for pointing out how much human effort went into assembling what we now regard as commonplace knowledge. I believe all science courses should begin with an overview like the one you've presented.
Arghhh… my brain hurts! I’m so glad we have smart people like you around. Thank you.
This channel is my weekly astrophysics lecture
I think I was rather fortunate, because in primary school, there was one teacher who was rather passionate about science and he passed on snippets in chemistry and physics to all the adoring sponges in his class. It was he who kind of inspired me (and others) to pursue the field of science _AND_ the ideas in evolution (!) in later life. I often feel that many of the concepts in science related to our day-to-day existence ("Observe and Measure") should be taught. It's not difficult at all (well, it wasn't to me anyway :0) I'm a retired scientist now (forensic entomology ~ though I also did degrees in foundational science and also computer science - for the fun of it really! I'm still an amateur astronomer and enjoy just looking at the heavens!! Thanks Dr Becky once again!
Your such a brilliant teacher Dr Becky, I wish I had you as my science teacher in comprehensive
Wow, dr becky for you to explain the universe, you are the next Newton of today, incredible clarity and memory to rattle the numbers so correctly, please keep explaining away
I learned much more than a semester in university just from this video!!
This was a STELLAR episode - information dense but exceptionally digestable. Thank you for putting it together for us.
إذا افترضت أن للضوء قصة أو حكاية يمكن أن تروى .. فإنني أعتقد أنك يا دكتورة من القلائل القادرين على سرد تفاصيل رحلة مذهلة ... و خصوصا تلك العلاقة التوأمية مع الالكترون .. أو في أي حقل أنت ملكة الاختيار ..
ان حدث هذا سيكون أمرا رائعا في اعتقادي بالرغم من ضعفي و قلة خبرتي في اللغة الانكليزية و التي أعمل على اغنائها 💚
I remember the first time EMC2 came up in a physics class; talking about subatomic particles, putting a few calculations on the board, cancel a few terms here, substitute this over there. He played it slowly and when we all realised where it was going was, it like the DiCaprio pointing meme
I was thinking on going there in just over 5 billion years. Thanks for the heads up ! I will pick another 🌟 for my holidays.
becky thanks for your great science videos. Thanks to your very understandable pronunciation, I can learn English in addition to the exciting astrophysics. its charming and authentic charisma makes it one of the best additions to reading a book or sitting in an auditorium and listening to science!
Hi Dr. Becky, what a brilliant video, great explanations with your incredible knowledge and great style and so beautiful to watch xx
I would love more videos along the same lines as this one, using first principles to show how things were determined
Alexander Wallace first principles = underrated
Best explanation on every thing involved in deriving the age of the sun. Thank you.
Seismology and trigonometry: also from greek!
Excellent show.
I plan to show it today to my son to help the understanding of acquisition of knowledge for his IB TOK.
Thanks again.
At the beginning of the video, you asked what the most famous physics equation is. I honestly never learnt E=mc2. I answered, Speed equals distance over time. And then later on you totally said the thing :D
I love trig. Was amazing at it. I went to a very disadvantaged school. We didn't have physics. Too bad I didn't have an education to be able to get a good job to be able to earn money to go to subscribe to Brilliant. You're a great teacher Dr. Becky :D P. S., I was the only one in my school that knew how to transpose an equation. Too late now though :( I guess I'll leave it all to you :) The only thing I learnt in 6 years of high school in "science" was the act of peristalsis haha. I honestly am freaked out by human anatomy. Give me astrophysics and cosmology any day! Best wishes.
Gotta say that that was some brillant deductive reasoning with undisputable facts thrown in Dr. Becky. Now I know a lot more about the age of the Sun & how long it has to live, give or take a few billion years.................👍👍🔴🔴👍👍
Excellent vid Bex! Tons of great stuff in this one. x
I loved your explanation of how we can determine the time left for the sun to live using those seven different key points.
What a fantastic explanation of such a relatively simple sounding question. It makes me appreciate the bigger picture and the process of how the suns age was calculated. Plus you make it understandable to a degree and present it very well. Dr. Becky, you have a long time subscriber. Keep up the great work
I love your videos Dr Becky but this was my favourite so far.
18:55 - "I can safely say that nobody understands quantum mechanics.” Richard Feynman (1965). (Brilliant overview of all the incredible research across so many different scientific fields!)
This video is great and your channel is litterally fresh air on youtube. Thanks a lot.
Dr B is a fantastic communicator. Great job!
Well done Dr Becky! That was an amazing video! As others mentioned in the comments, be explaining the scientific steps in which scientific facts take form one can understand that science is not a collection of data but a way of thinking! Truly great video!
Thanks Dr. Becky I learned something new.
There is one thing unclear to me. When you calculate the mass of the sun, it is the actual mass of the sun, not its initial mass. So, why it is not the rest of the sun life that is calculated instead of its whole lifespan ? Bravo for your videos. Always captivating.
Great video! Never seen such a detailed explanation of Sun's remaining age. Thank you.
Also, I saw on another channel some time back that although Sun will live for another 5 billion years, Earth will not remain habitable for more than few hundred million years or so, due to increase in Sun's luminosity.
It would be amazing if you can cover that in one of your future videos.
Fantastic video. Every science student should see this.
Thank you @Dr. Becky! I recently discovered your channel and am enjoying all your videos. I’m sending this to my mom even though it will probably bother her to think about...it also seems to bother her when I talk about how in less than 100 years she and I will almost certainly be dead...so the ~5 billion years of sun life left should not bother her or me...great video!
I love it. I am 70 years old. Sol will outlast me by about 5 billion years. I might get 2 or 3 more suntans. In 100 years who will care? Thanks, Doctor, for drawing my attention to my lifespan, in relation to the Vast Universe. Love your work.
Can we add some more flags with a follow up? :) thank you!
1: Luminosity (Solar irradiance or TSI for climate data formulas):
-Does this account for all particles and matter states? (thinking a light bulb that's turned off still has mass, or about x-rays given off other particles/waves etc)
-If we use Luminosity again is this answering why the corona is far hotter than the underlying layers and how that would explain that it's purely burning itself for fuel?
2: E=mc2 ( what is mass if it's matter, what is energy? if we don't understand how gravity works and only describe it by describing its effects or itself to describe it i'm sure we understand mass or if we're correct in the age of the sun or life span.
3: Gravity/speed of light limitations
Even with an 8min delay for light if gravity communicates with the earth by way of a single directional force of acceleration at that latency we'd never achieve stable orbits that remain 'constant" if there were ANY other variables introduced. We just added dark matter and black holes, we never solved the problem. Currently the gravity formula/model fails to account for the rotation distance/speed fall off of galaxies which means we don't have that calculation correct or the speed at which information can travel and why.
okay 21 more mins to go!! weee
And we have another great teaching moment. Thank you, Dr. Becky.
A little side note on calculating the circumference of Earth's orbit. It's actually much more circular than most people think, because it comes extremely close to matching a circle whose center is offset from the Sun by the eccentricity, ea, where e = 0.016, and a = 1 AU.
Its fractional deviation from the "offset circle" of radius a, is on the order of e².
Note that this remark is meant only as a little extra information in support of your (quite excellent!) presentation here.
But wait - as you go through the back-of-envelope calculation of the Sun's age, you have 15 Ty.
Then using the 10% of its mass that is fusing, takes you down to 1.5 Ty.
Then you fold in the fact that only 0.3% of the hydrogen mass gets converted to energy. Shouldn't that bring the lifespan down by a factor of x0.003, to 4.5 Gy, not 10.5 Gy?
So was that 99.7% figure supposed to be 99.3%, leaving 0.7% mass conversion? Which would have led to the stated lifespan of 10.5 Gy?
Or is there something I've missed here?
At 6m 43s, in your final formula for M[Sun], "365.25 days" in the denominator, should be squared.
16min: "Gamow" is pronounced, "GAMM-off."
20m 40s: ²³⁸U decays to ²¹⁰Pb, not ²⁰⁷Pb.
This follows from the fact that the decay chain is entirely α and β decays; the former always reduce the atomic mass number, A, by 4, while the latter always leave A unchanged.
So the final A value must differ from (be lower than) the starting value by a multiple of 4.
Overall, this was a totally splendid presentation. I think it's the best, most concise, and solidly factual exposition I've seen or heard, in answer to this question.
Kudos!
Fred
This video is pure science and I love it! She takes a huge subject and breaks it into individual provable parts which is by far the most valuable skill when it come to scientific communication. I would take any class taught by her!
8:30 Trigonometry was my great nemesis in my school years, I never had problems with numbers at school, in fact math was always easy for me except for trigonometry, no matter how hard I studied and studied, I never fully understood it
I'm so glad I watched this video. I've always had these questions☺
I found this to be one of *the* most fascinating videos you've done. Absolutely superb presentation.