How We Know What Happened in Earth's Past, like Ancient Climate, Geology, & Extinctions | GEO GIRL
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- เผยแพร่เมื่อ 6 ก.ค. 2024
- We reconstruct Earth's ancient past using physical, chemical, and/or biological signatures preserved in rocks, called proxies. From such proxies, we are able to reconstruct ancient climate trends, like temperature, atmospheric composition, ocean chemistry, oxygen levels, carbon dioxide levels, mountain chain positions, elevations, plate tectonic events, volanic eruption events, earthquakes, wildfires, ocean anoxic events, impact events, glacial expansions and contractions, sea level rise and fall, etc. as well as biological events, like evolutionary and extinction events. In the many Earth history videos on my channel, I go over such events, but in this video, I go over what kind of proxies we use to reconstruct such ancient events and conditions! I know this video is long, so I broke it into sections, which cover physical proxies, chemical proxies, & biological proxies, respectively. I also included chapters listed below and on the timebar of the video for you to use if you'd like to skip to a specific section. Hope you enjoy! ;)
References:
Zachos et al., 2001- Trends, rhythms, and aberrations in global climate 65 Ma to present: doi.org/10.1126/science.1059412
McElwain & Punyasena, 2007- Mass extinction events and the plant fossil record: doi.org/10.1016/j.tree.2007.0...
Falkowski et al., 2005- The rise of oxygen over the past 205 million years and the evolution of large placental mammals: doi.org/10.1126/science.1116047
Hayes, 2001- Fractionation of the isotopes of carbon and hydrogen in biosynthetic processes. Reviews in mineralogy and geochemistry: doi.org/10.2138/gsrmg.43.1.225
Delano, 2001- Redox history of the Earth's interior since ∼ 3900 Ma: Implications for prebiotic molecules: doi.org/10.1023/A:1011895600380
USGS Article: www.usgs.gov/programs/climate....
0:00 How we reconstruct Earth’s past
5:22 Why we study Earth’s past
7:17 How paleoclimate proxies work
9:09 Physical proxies
17:18 Chemical proxies
18:02 Stable isotope chemical proxies
20:53 Carbon isotope example
24:29 Oxygen isotope example
29:27 Sulfur isotope example
33:49 Trace element chemical proxies
38:01 Biochemical proxies (biomarkers)
40:23 Biological proxies (fossils)
41:07 Terrestrial biological proxies
42:48 Aquatic biological proxies
48:10 Honorable mention proxies
GEO GIRL Website: www.geogirlscience.com/ (visit my website to see all my courses, shop merch, learn more about me, & donate to support the channel if you'd like!)
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Hi all, if you are new here, my videos aren't normally this long haha! This topic just happens to be closer to my research field than most of the topics I cover, so I got a bit talkative ;) I decided to put this one out full length because I felt that it didn't flow as well when I broke it up into smaller chunks. But don't worry, I will make future videos with pieces of this information included in smaller, more digestible chunks ;)
Also, I tried a new recording set up in this video to improve the audio quality, as I know it was a bit screachy for the headphone users before. Audio has never been my strength and I have never really had the 'ear' for it, so if it is improved or worse, please let me know! I think this way of recording sounds better with headphones than it did before, but I still hear a little echo so maybe I just need to better echo proof the room I record in now. Anyway, thanks in advance for any feedback! And I hope you all enjoy learning about this topic as much as I love it! :)
P.S. I just realized, also, that the audio and video weren't matched up perfectly, I am sorry about that! Just pay attention to the slides in this video instead of me lol! ;) I will try to be better about that in future videos ;)
Could you talk about the climate of 125 thousand years ago? I hear we recently surpassed the temperature of that time, and also at that time the earth was between extinctions. Maybe I heard it wrong but it didn't sound right to me.
@@wedgewizard5429 I'll look into it, thanks for the suggestion! ;)
Long videos are great! Thanks for another lovingly produced video. This helps me to learn. The history of earth is so incredible, you don't even need spooky short music with paleo art to make it epic!
I absolutely love how you laugh at your own geology jokes its just too adorable. 😂😂😂
Your smilles give life to the rocks.
So basically, you use multiple independent lines of converging evidence to reconstruct conditions in the past. That gives me a lot more confidence in these reconstructions. I really liked the detail you went into in this video. This is exactly the sort of thing that made me subscribe to this channel. This was just really well done. Thank you.
Exactly! Thanks so much for this comment, I am so glad that came across ;)
I will subscribe. I normally do not watch channels that have a full screen of the host and a little inset of the data presentation. This person does it the opposite way and I love that. I can actually see the data presented. TY Geo Girl.
... AND you engage! Physics Girl (who I love to death) didn't even do that.
Oh wow, I cannot imagine doing the other way, how do those people expect to show the data? I agree, that would be less than optimal! I myself, wish I could make more 'high production' videos (aka: not just boring old powerpoints lol), but in my life currently, I just don't have the time. I hope at some point in my channel to do so to make these more interesting though! ;)
@@GEOGIRL Yet you made the time to reply. TYVM! Fast fan here.
Great video! As a paleoclimatologist, I thoroughly enjoyed how succinctly you conveyed each of the proxies discussed. The thalium proxy that you are helping to develop sounds interesting.
Thanks so much for this comment! It always feels so good to have validation from other paleoclimatologists and paleoceanographers :)
@@GEOGIRL >> Hey Geo Chick, did U know that when you complete all core STEM courses, i.e., Chemistry, Physics, etc to Meet your
Qualification for a B.S. degree in Geology, you already Exceeded - all STEM courses required to apply for (M.D.) Medical School?
before U started on your Masters, U easily would have passed the MCAT, & now been finishing Med-School.
oh man this video is EXACTLY what i was hoping for
i have a doubting family regarding climate change.... i need to explain the scientific consensus well enough to override the bothsidesing
THANK YOU i will be rewatching like a sponge
Love this comment! So glad you found it helpful and confirming regarding past reconstructions. I am so close to this research that I find it so interesting but also so well backed up, I just never know if it comes off that way, so I am glad it did :)
This reminds me of one of my favorite quips in history. When a creationist asked J.B.S. Haldane what it would take for him to stop believing evolution, his response was simply "Finding a rabbit in the cambrian layer." It goes without saying this has not happened, haha.
Haha, I didn't know about this, that is a great response :)
The only thing I know of J.B.S. Haldane is a clever quip, but a completely different one. When asked what, when witnessing living things, could be assumed about a Creator, he answered, "An inordinate fondness for beetles."
@AisuruMirai Yes! If you google, "How many beetle species are there?" The number is staggering!
Yay! I’ve been waiting for this video since your community post about how long it should be😂
Haha! I am glad to hear that, thanks for watching! I hope you enjoy it ;)
Fantastic! What an amazing, informative marathon of a video! I look forward to seeing this lecture forming the core of your NYT bestselling book: “Geo Girl: Finding Our Past, Present and Future in the Rocks”. When can I preorder my copy?!? 😁☺️
OMG that is a brilliant title haha, I don't think I am knowledgeable enough to write a book just yet but maybe someday ;)
@@GEOGIRL
I'm sure you work with people who do have that knowledge, and who aren't as articulate as you are.
So a collaboration book with both (maybe several) of your names on it would be a really useful book.
Sitting down to listen to this, but my initial impression of the title is good. Very important for scientists to explain the why, the process of reconstructing the past, methods of observation, etc.
Very good! i was kinda waiting for this one when you mentioned a longer format on a community post, and its great. The audio/video was a nice improvement, your cadences were pronounced despite trying to cram so much in, keep refining the format! Great job Rachel, GEOGIRL Rocks!
Thanks so much for the kind words and feedback! I am so glad that the audio sounded better, I think I am on the right track and I finally know how to make it better, even from here, so that's great! That was a big hurdle for me for so long! I didn't realize it was not just getting the right mic, but also recording with the right software, who know?! lol ;) Thanks again!
Geo mom agrees ❤️😊
@@GEOGIRL Absolutley! not everyones born with an ear per say, but like anything, it can be trained. lifes a lesson, so if your not learning your not living! im very excited for you tho!!
Mummified trees etc on the Axel Heiberg Island are a fascinating evidence of warmer climate during the Eocene.
Speaking of trees, I recently found out that during (I believe it was the Eemian period) that trees actually grew on the southern parts of Baffin Island.
Today they don't even make it all the way to the most northern parts of Quebec which is a long ways south of Baffin Island!
I thought I knew quite a bit about radiometric dating, but you've shown me a whole other level of stable isotope study. To think that mass fractionation on these levels can tell us so much about the chemistry taking place on ancient earth is fascinating. Thank you so much for making content like this.
cool video thanks i feel like I'm getting a Geology degree just by listening every week :)
Haha I love that, so glad you enjoy the content! ;D
Every single one of your lectures/videos are important and valuable. Every. Single. One. Nevertheless, this one has to be one of the most important. At least in the top twenty. This video is geology, or even better, “earth science.” Thank you. Alan
Thank you so much! This is possibly my favorite video I have ever done in part because of its close association with my research, but mostly because I also think this topic is super important for people to understand, and it is unfortunately not super widely understood knowledge (yet) ;)
I am so glad you enjoyed it and appreciate its importance as well! Thank you for the comment :)
You and Science Mom are two of my favorite science presenters. I love anything science related, but Geology and Mineralogy are two of my favorites.
One of the older shark week episodes I was involved in was with Woods Hole Oceanographic. Doc. Greg Skomal was our "talent." It was one of the "Shark Cam" episodes in 2014 or so. They basically modified REMUS drone to film White Sharks. As a bonus, the little drone double as a chew toy for the sharks. If you ever watch it "Jaws Strikes Back" or maybe "Jaws of the Deep?", about 20 min in I get a few seconds of my "20 minutes of fame" they crash zoom to me yelling "White Shark!"
I've worked with Woods Hole a few times they were always fun to work with and I always learned something new from them.
Great video.
Cool story thanks!!!
My MS research related to marine red beds and this video help me a lot.
Thank you so much.
So glad to hear that, best of luck with your MS! ;)
It's a good day when Geo Girl uploads. Even though my training and profession is faar from geology or the topics you cover, your explanations make it approachable and quite interesting to watch and learn. Kudos 👌🏽
-Cyril, Mumbai, India.
Thanks so much! I am so glad to hear that you enjoy my content despite a different background :)
You're the BEST! Keep up the great work 💕💕💕
Nice overview Rachel, time flew by, well organized. ❤
Great long video :D
You mentioned your own research here. It would be cool to see videos about your research itself, rather than just a related topic
I have some more technical video lectures/talks I've done for my university and conferences that are about my research (in my "me & my research" playlist: th-cam.com/play/PL69bBhmsrgfvf4VWMuNjPzZA6RyMddEBT.html), there is also a presentation I did for an AIPG webinar on youtube as well (th-cam.com/video/BFKI5TDpzQE/w-d-xo.html), I even have my practice dissertation proposal defense unlisted on youtube haha (here's the link if interested: th-cam.com/video/LtV8CMKWUfc/w-d-xo.html), but I don't really have a video about my research that is in depth but targets a more lay audience (at least not on my channel, I guess this is kinda what the AIPG talk was), so I will put that down as a future video to work on, thanks for the suggestion! ;)
@@GEOGIRL thank you for the links!
Very comprehensive. Something here for everyone. The sulphur isotopes was new to me.
"If you didn't understand that, just trust me..."
The Catholic, most Orthodox and Mainline Protestant position is Theistic Evolution. Evolution, cosmic, biological, cultural, is seen as the unfolding of a Divine plan (ultimately unknowable) through the workings of natural law and human cultural development. Biblical texts are read using historic, form, redactic and literary critical tools.
Great presentation, inspired me to get my old copy of Clark and Fritz out of the bookcase.
It's incredible living in TX and it still has reminders today.. Millions of years ago it was underwater a sea/ocean bed.BLOWS MY MIND!!!iii
Here is what I got: the same chemistry gives vastly different results depending on what is already present. Good job! you gave us alot to think about. it is easy to see there is alot more to it.
Fantastic material of English learning! Thanks a lot!
Gotta love geology... can't get very far back with tree rings , ice cores , etc...
Agreed, rocks are the best ;)
glad I found you, I needed the interconnected remedial lesson.
Excellent geo girl thank you
Deeply informative.
Your channel is so good for info🔥💯📚
Thanks, very cool. Well taught, not talking down at all. Use to run the fractionation tower in the oil field so I can relate.
Sweet! Another long form vid for me to go over a hundred times (I got a back log) while autodidactically cross refferencing. 👍
🤔 Well, I guess it's not quite autodidactic if I'm leveraging teachers, lessons, videos and textbooks on the internet.
38:49 Bryophytes is the informal group name for mosses, liverworts and hornworts
Thank you for this full and comprehensive lesson in Geology! You rock 🪨 and science rules 📏!
Thanks so much! I am so glad you enjoyed it :D
Can you do a video on ice core dating in polar glaciers? Whether the rates of deposition are constant or not? And how we can know?
very informative and interesting.
Thanks! So glad you enjoyed it :)
Videos like this are excellent for both interested people (like me) AND people who say "We can't possibly know that's what happened way back then", like... here's how we do know, the fact is that YOU didn't know how. (I wish I could show this to an annoying person who used to throw that argument around when I was a teenager, and since I was a teenager, I didn't have the knowledge to drop some heavy facts on them.) Carry on! We need more freely available information of everything, and you're definitely doing more than your part.
Thank you so much! I am so glad you feel that way about this video, everything you said about it was exactly my goal! :D
I have in my mind right now that famous drawing of James Hutton talking to rocks...
Well done! 😊👍🏻
Thanks! ;D
Updated names for the Geologic Time Scale:
4.6 - 4.0 Ga: Hadean Eon
4.0 - 2.4 Ga: Early Wonky Mass Independent Fractionation Eon
2.4 - 2.0 Ga: Proterozoic Eon
Etc...
In the arid desert of click bait, shallow debates, banal noise of innumerable types, I am very happy to find your oasis of intelligence, facts, explanations (at a much higher than kindergarten level), enthusiasm and enjoyment in studying this planet. I grew up in the precomputer age, where I had to use a slide rule in math and physics classes. There were certain advantages to that of course, but one of the disadvantages was lack of something like this channel to enjoy. Please, continue this wonderful work you are doing here.
Thank you so much for the kind words! ;D
@@GEOGIRL You are most welcome. Teaching is an art, as well as a science. You are very gifted in both of these areas, as well as having a personality that encourages interest, and a desire to know more. You are in a great place, and filing that special place exceptionally well. Keep it up, please. 🙂
You are great personality of world ❤
How cool that we can basically wind the clock back on the World.
I know right! How much cooler can it get?! :D
Cool!👏👏
hi this was great - maybe a follow up can be of the earth’s future, ie., continental rifting, east africa rift, etc.? 🎉
lol geo girl being able to read out all those element full names so fast from their symbols is really impressive!
Very educational video thank you very much! I don't usually look at geological record as a hydrologist but it's very interesting that these events have occurred in the past and are not isolated event happening only to us!
Love it! Data-data-data!
"The oxygen history of the earth."
Perfect!
So, in the past fifty years, is the oxygen content of the atmosphere up or down?
Hint: it's down, and by more than CO2 is up!
Personally, I'd be more worried about lack of oxygen than polar warming. (Fact: the tropics aren't warming. They're steady. The poles are warming.)
Dear one! Your enthusiasm and dedication to truth are amazing! You had me at your periodic table bed comforter (a place where chemistry happens) (*). But would you give up a career to throw one knife at a mountain of deceit?
I've installed a Planetary Air Conditioner, and no one cares. You? Millions of views because you are cute, smart, and spunky. These traits will fade (smart has a longer half-life).
You are in a temporary position of influence. Give some thought to legacy. Most people don't get this chance so young.
Good luck!
(*) Please check into putting that periodic table bed thing into your merchandise list. I don't know if you can do it, but it's worth a try!
Unfortunately, I got the periodic table from ACS (american chemical society) and I have looked for it since and I cannot find it :( I wish I could link it for you guys! Anyway, thanks for the comment, the extra info, and the kind words! So glad you enjoyed it! ;D
Thanks!
Thanks so much! So glad you enjoyed it :D
Eu sou alguem que ama vídeos longos... Pode fazer vídeos de 1..2..3 horas e eu vou assistir com grande alegria... ( e comendo um bom lanche no processo )...
Adorei esse vídeo e sempre aprendo muito com você ( e aproveito para melhorar meu entendimento do inglês )... Um abraço do Brasil para você!! Obrigado pela agradável aula!!
Aw thank you so much! I am so happy you enjoy my videos, even the long ones! That is great to hear, thanks for the comment :)
Proxies, proxies EVERYWHERE.
Your knowledge is very impressive.
Thank you, I wish it was all my knowledge, but only for a limited time til I forget what I read lol ;)
At 34:20. I thought you were going to sing the periodic table song. Well done your longest video is great.
Hahaha just about ;)
Hi! 👋 I took all the sciences in college,, but never took Geology,,, which has me super curious for some basic rock and chemistry tests now.... My sister is breaking rock in these hills of south-western Missouri to build her house... Can you do a video or collab on how to test the geology with chemistry? Love the vids and all your extra effort! 👍
Maybe a collab with @NileRed
Bryophytes are liverworts, hornworts and mosses. Beyond UV radiation as a cause of isotope fractionation, I'm also thinking in a minor way about lightning strikes which were supposedly far more numerous millions of years ago than the million or so per day we have now. Lightning giveth and lightning taketh away as Miller-Urey would suggest.
Oh, thanks that is super helpful info! That's a great question about lightening, I know there was a time that it converted some atmospheric N to other N compounds, but I don't know if it fractionates isotopes, I'll have to look into that ;D
28:58 Why does the temperature curve based on oxygen isotope ratios become more broad with less time past?
A couple reasons: in part this broader appearance is due to the up and down (glacial & interglacial) spikes and dips in the modern ice age, but the second and bigger reason is due to the fact that we just have more rocks/fossils for more recent time and thus more data for more recent time :)
@@GEOGIRL Ah thank you :)
often, when learning a subject like geology, we know so little that we will accept whatever the textbook reports, and ensure that we get the answers that the course requires. But when we look at the subject from outside of the structured course we can see problems with the conclusions and the methods and the assumptions.
For instance, we have recorded 100+ years of climate data and never do we observe wind blowing in a consistent direction for a period long enough to put striations into 100' of rock.
What are your thoughts on the effects of animal agriculture on the environment?
It's bad. ;) I mean in many ways, on the animals, on the atmosphere, but mostly on water usage from what I've read.
16:58 time stamp- the left pic---do we know if an impactor caused the Bonneville floods ?
Is it correct to say that before radio activity based aging we still had notions of the world's age expressed in millions or billions of years instead of thousands, and if so, how did we know then?
Actually I have an entire video discussing all the times we tried to date earth before radiometric dating, check it out here -> th-cam.com/video/suUX9-JAwNM/w-d-xo.html it should answer all your questions :)
How do you measure current temps when it takes large amounts of time for rock to form? Are you relying on weather stations data to measure temps the last 150 years?
Yea, so for more recent history (hundreds to thousands of years), we tend to use non-rock methods, such as our direct measurements, tree rings, ice cores, quanternary foraminifera, etc. The rock dating methods are typically only employed when we are studying periods millions of years ago because the error bars associated with those ages are much larger, for example, many times we say that a rock is around ~540 millions of years old +/- a few million years. Sometimes we can increase the precision with additional measurements from other rock samples, but in general we tend to gain an accurate but not super precise age for super old rocks or events :)
I was studying the moon.... and its history is amazing! I am trying to imagine the history of the earth, and so far I realize I've been imagining the sun and the earth system, and assuming the moon is always the same... but its used to have a magnetic dynamo... perhaps it shielded the earth? and its spinning is responsible for slowing the day from 5h to 24h...and it used to be closer, and its responsible for tides, and I'm sure if the moon was closer, the tides would be bigger.... but I don't have data on moons orbital history, and its effect on icehouse vs greenhouse... perhaps its a good idea for a video...
Great video! In the section on preferential uptake of 12C (time mark 21:00), it would have been nice if you had briefly mentioned the kinetic isotope effect. I know you are trying to strike a balance between simplifying the info versus getting too far into "the weeds" and bogged down with detail.
Young Earthers be like "Nuh Uh!"
Mam can you suggest or reffer me book for Applied Geology (Hydrology,geo-exploration,fuel geology, geomorphology and Remote sensing)
NO FOSSIL FUEL, NO MINING ...anywhere, GFY
Leave it in the ground
I heard they can make batteries out of clay. Im sure the worlds endless free energy is stored in clay. Do me a clay video again? If anyone can figure out how to solve some of these things its you. 💚
Haha, okay I will look into it! ;) People do seem to really love the clay content lol! :)
Greetings Geogirl!😊! I wanna ask a question? There is a geological structure in East Africa called East Africa Rift do you think Africa is currently in the process of splitting up into two land masses?? Can we expect a new ocean between them?? Or is it a failed rift?? Do you think that South America and Africa had similar rift before they got split up and formed Atlantic Ocean???
Yes, the East African Rift is an active rift and is moving most of the African continent west and the eastern-most sliver east which may eventually form an ocean basin between them (similar to how the Atlantic formed). However, it is important to note that this prediction only considers the movement of this one plate boundary. There are a bunch of other plates on Earth moving in different directions that could affect this rift. For example, the Altantic oceanic plates spreading from the mid Atlantic ridge are pushing Africa/Europa and the Americas further away from each other, and as this movement continues it could overcome the forces pushing Africa west, and that may create a subduction zone at the western margin of africa where it is now just a passive margin. This subduction zone could slow or completely change the trajectory of the rift zone. I am sure there are people out there running models of the magnitudes of force each plate is pushing with, the rates they are moving, and this may help predict what may happen, but it is hard to say. So I guess the answer is it is possible an ocean basin will form between them, but we don't know for sure and it will also not be any time soon, so we would not see it, it would be millions of years in the future :)
so it depends on more than one major tectonic plate huh??? Ok thanks 👍 yeah I have seen many possible scenarios for the movement of tectonic plates and what could be the future positions of continents like Pangea Proxima ,Novopangea.etc but sad we won't be alive to see those 😅😅
Geo Chick, did U know that when you complete all core STEM courses, i.e., Chemistry, Physics, etc to Meet your
Qualification for a B.S. degree in Geology, you already Exceeded - all STEM courses required to apply for (M.D.) Medical School?
before U started on your Masters, U easily would have passed the MCAT, & now been finishing Med-School.
🧬
😎
Have you thought of doing a video or two, Rachel, what geochemistry is for the layperson?
Thanks for your videos. I did notice a slight misalignment between audio & video but not a distraction. I was more distracted by your tee shirt. I think I need a JWST t-shirt.
Also, good to know where to send those few climate change deniers who poo-poo use of proxies for paleo climate reconstructions. I only knew of a few and not as detailed as your presentation. (Although I don’t think even your expertise would alter their views, it’s useless to argue with someone who’s stance is that all science is unreliable).
Thanks, I did learn a bit more, as I usually do watching your videos.
Agreed, based on some conversations I've had with some people like that, they are not super interested in truth, they just like to argue because they want it to be a lie. It is unfortunate, but hopefully people (at least the people that matter and can make change) will eventually come around :) In any case, I am glad you think the video does a good job of explaining the general concepts, thanks for the comment! ;)
I am student of psychological science
But but but... The land masses were in different places millions if years ago which would really throw a crap-ton of uncertainty into what local climates were really like.
Yes, but we are able to reconstruct paleogeography (ancient positions of continental landmasses) and thus, we consider that when we make climatic reconstructions so that we can say exactly where that climate was present. This is a big piece of the puzzle when reconstructing the extent of ancient ice ages, for example. We have too take into account the ancient latitude of the landmasses on which we find glacial evidence, so that we can say, we found the glacial record here, but we know that was at the pole during the time these rocks were deposited (or rather, it was at the equator, which would indicate a potential snowball earth event!), and so on. Climate reconstructions are never made without consideration of that deposit's ancient location. Hope that makes sense :)
direct evidence - pollen from juicy plants doesn't turn up in deserts, trees don't have small growth rings in wet years
Is it me or is the production level increasing?
Love to hear that! I improved (or attempted to improve the audio on this one, so I hope it worked) :) I will continue to improve though, got a long way to go ;)
You mentioned Carbon, Oxygen and Sulphur isotope ratios, Rachael, but it occurred to me that there's at least one other element which is vital to life that you didn't mention and that's Phosphorus isotope ratios.
That would be because phosphorus only has one stable isotope, so there wouldnt be any information to be gleaned from it.
Hi Dear Please Start Mining Geology Course I am very Interested In this Course. I Shall be Very Thankful to You. Lots of Love From University Of Swat Pakistan
Do you have a wikipedia page, Rachel? If you don't you should get someone to set up a wikipedia page for you.
is it not possible that the procedures we use today can be incorrect
People like to say that Archaeology, Paleontology, and Geology(and even Astronomy!) are very different from Mathematics and Physics. They'll point out Astronomy is only observational whereas Physics is experimental, and Mathematics has logical proof, and science in general does not. I'm always struck when I see Mathematical things in Science in general - not just in Physics, but Paleontology, and even in Geology!
Like for instance, in Human Evolution, they recently found the Denisovians, not by digging up their fossiils, but by noticing them in the genetics. Then, they went and dug up their bones. Similarly, Charles Darwin's "The Descent of Man" pointed the way to Human evolution in Africa before they found Australopithacines, and Homo Habilus. This is kind of like the physicists Paul Dirac predicting anti-matter, and then anti-matter being found just a few short years later.
I really kind of like the discovery of the finite speed of light by Romer example. He noticed different times of light from the motions of Jupiters moons. They had different times depending on the Earth being at different points in the Earth's orbit. Then, much later, Maxwell derived the finite speed of light from combining the Mathematics of electricity and magnetism!
People like to say science is just observing/experimenting and noting the same thing happens over and over again. Like watching the sun come up every day and saying "see, the sun comes up every day" That's their idea of scientific law.
I mean to say more; but, I'm not feeling like it right now. Hopefully, I come back to complete my thoughts here!
okay - so, I grew up fascinated with the nature and origins of Mathematical thinking. And, I've spent a lifetime reading, hiking and mulling over it. I actually dived into mythology as a kind of pre-mathematics knowledge. I appear to be close to getting a book about it all published officially(instead of self published on amazon).
Well, one thing I show in my book is noticing defining forms in Homer's Iliad. Suzanne K Langer talks about defining forms in her "introduction to Symbolic Logic." There's a concept, but there's also defining forms which are kind of like concrete manifestations of the general abstract concept. . . . Jacob Bronowski notes in his "Science and human values" facts only come on a propositional level. That you come up with your concept first, and then you can ask what the facts are. He likes a Shakespear example "is this a dagger I'm holding in my hands." I'm leaving out some details, but the coming together of various concepts into the abstract concept is like the various defining forms. I found and put in my book a Homer's Iliad example where the character is seeing the enemy doing some impossible manuevers. And he says "that must be a god, because no mortal can do such things."
Getting into some more Jacob Bronowski. In his "Origins of Knowledge and Imagination" he notes that when we make our first idealization in nature, it is a finite cut. Well, you make your finite cut, and this leads to numerous more 'questions." Suzanne K Langer's defining forms are like all these questions that result from making a finite cut in nature.
I enjoyed this video, but certainly many if not all previous Geology videos you've made here, because all your proxies that checks each other is like the defining forms that fit in with each other.
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17:10 Glacial retreat just strikes me as such a funny term for deglaciation events. 😅 I'm picturing a cartoon glacier running away from Gran Crood yelling, *_GO ON, GIT_* ‼️ _And stay gone._ 😂
On your line of study, at what point do you realize that life is spontaneous. Or have you ever?
Hello my friend. I am interested in amateur astronomy and seismology. I can share information with you. I live in Turkey. I am a physics lecturer at Sakarya University. Kind regards.
A woman as beautiful as you can never be wrong. I will accept everything you say and do.
In the very beginning, the earth was as soft as a dinosaur egg yolk.🦕 The earth today is as hard as a turtle.🐢 Is the turtle's body temperature constant?🍳
Bryophytes, a group of non vascular plants that that contains liverworts, hornworts and mosses. Google is your friend. 😜🤭
Thank you! I tend to google things I don't know before filming, but I missed that one and by the time I was filming I couldn't be bothered lol ;)
49:50
Luckily, I just listened to most of this but your lack of lip-synch towards the end makes it unwatchable.
Why does that happen?
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I know that was my bad for this video, I changed the way I recorded and didn't realize the bad sync til after posting. Just pay attention to the slides for this one ;) I'll do better on future videos!
@@GEOGIRL
Yeah, I hate that. I'm hyper-sensitive to that sort of thing, horrible voices etc, such that I sub to people who I can listen to even if their content is not all that, whereas some people whose content is excellent, I cannot listen to them because of their horrible voices.
EG (Schlupp) that guy (Schlupp) Steve (Schlupp) en Pink (Schlupp) erton, I (Schlupp) just cannot bear (Schlupp) to listen to (Schlupp) him because of (Schlupp) his horribly irritating (Schlupp) habit of slurping and (Schlupp) wet clucking as he talks (Schlupp).
And there's some incredibly annoying atheist evolution girl I cannot bear as well. I forget her name.
But you're OK, top notch content and (usually) top notch presentation! 🤗
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Today I learned: 🌈⭐
Bryophytes are a group of a land plants, sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. In the strict sense, Bryophyta consists of the mosses only.
en.wikipedia.org/wiki/Bryophyte?wprov=sfla1
Mosses are cool
The problem comes when people make assumptions based on past assumptions that turn out to be wrong. Then people are to invested in the old way of thinking that the new evidence can't possibly be right. The earth expanded from a smaller sphere roughly half of its current size. This is still ongoing today. There are multiple lines of evidence that are ignored. Now the only question left is why.
Ha ha ha ha ha ha ha ha ha - good for you
debunk Montana wall.
"debunk Montana wall." - Every house has walls. Montana has houses. Therefore Montana has walls. See how easy that was?
This sounds way too hard. I think I just told a geologist their job was hard.
I mean sure science can be hard, but it is SO COOL! And so WORTH IT :D
...And I'm back!
Had a quick little home improvement project to work on, and I wanted a tutorial to make sure I wasn't overthinking it.
Voila! 🎉
Earth is best balanced when CO2 is around 1200-1800 ppm
Well, we can't really say that because what does 'most balanced' mean? It would depend on what life was on Earth at that time, where the continents were, whether they were separate or in a super continent, over the poles, etc, the ocean circulation patterns at the time, the remaining atmospheric composition at the time, whether photosynthesis and/or respiration was occurring and to what degree, there are just too many variables to define a 'most balanced' term. It also depends on the rate of change of the CO2 concentrations. If it decreased or increased to get to that level gradually, then life would likely be thriving, yes, but if it decreased or increased to get to that level rapidly, then life would have likely been hit was some major extinctions. Remember, it is the rate of change that makes climate change harmful not the magnitude ;) Hope that makes sense! :)
I should've typed "earth is at it's greenest🤪
You've got me taking notes👍👍 preach on sister💪
"Earth is best balanced when CO2 is around 1200-1800 ppm"
The Cambrian fauna and flora would disagree. That's too low
The Quaternary fauna and flora would disagree, That's too high
etc..
Well, you think you know. From a sub quantum level no one knows.
We do NOT know what the climate was like in the past.
Anyone competent at science will never claim we KNOW such things.
Especially things like temperature and atmospheric composition.
They will always emphasize that such guesstimates are impossible to scientifically verify.
Yes, that's a great point, I had originally titled it 'how we reconstruct past ...' but I just felt like the term 'how we know' was a bit more widely understood, so I used 'know' but in reality it is more 'estimation' than actually 'knowing'. I think if people watch the video, that becomes clear :)
@@GEOGIRL Yes, I'm still watching it, and relieved to see that you're being more scientific (which requires fallibilism) than most reporting.
My one qualm (I very much value your overall video) is that you overstated the certainty about gas bubbles. It is essentially impossible to experimentally validate that gases do not change when trapped in a mineral (including ice), for millions of years. Individual molecules can get through salt or ice, for example. And that's aside from the loss of O2 or increase in CO2 from exchange with impurities in the minerals.
This could even explain the odd downward trend in historic CO2 percentage reconstructions. Perhaps the amount of CO2 in trapped minerals increases marginally, over millions of years, so that one gets the impression it increases in an overall-steady way going ever-farther back in time.
no offense, but you are a really good bullshitter, or you actually believe all of this. Either way your knowledge about this is impressive.
I studied physics, CO2 seems really unlikely cause of global warming. I followed the science, read both sides of the argument and ultimately determined that Dr. John Christy is probably right.
Please understand that there is no real consensus on CO2 role in climate change. Please be respectful of other people's ideas. Everyone thought plate techtonics was an absurd hypothesis until evidence mounted in its favor.
There is a consensus, and I know that because I've looked at the scientific literature from respected peer-reviewed journals.
How's that Shell money feeling in your pockets?
@@anticorncob6 yeah, peer review is complete garbage. There's quite a lot of fraud in science these days. If you're a research scientist at the university, it's publish or die. You're not motivated to do real science, you're motivated to get your paper published. You're at the mercy of the peer review panel and editors that drank the Kool Aid.
@@williamchamberlain2263 I don't work for Shell, but I buy their gas. You probably buy shell gas too. Difference is, I don't feel guilty about it.
@@anticorncob6 sure, here is what we know from observation: CO2 concentration is 420 ppm up from around 280 ppm before the industrial revolution. There's also been an increase in temperature around 1.1 °C. This is correlation, not causation. If the global temperatures are increasing, it's very possible that some of this extra CO2 was emitted by a warmer ocean. Furthermore the troposphere is largely opaque to infrared light because of water vapor. Also, attempts to grow plants in atmospheres with less than 150 ppm CO2 results in slow, stunted growth. These are all the things we can agree are consensus.
If you read the Bible it tells you everything