MinuteEarth

MinuteEarth
  • 2 минуты
  • 141 серия
  • MinutePhysics
  • earth
  • earth science
  • ecology
  • climate
  • geology
  • biology
  • climate science
  • climate change
  • history
  • global warming
  • environment
  • minute
  • illustration
  • animation
  • digital animation
  • graphic design
  • cartoon
  • After Effects

Science and stories about our awesome planet!
Created by Henry Reich, with Emily Elert, Alex Reich, Peter Reich, Ever Salazar, Kate Yoshida, and David Goldenberg. Music by Nathaniel Schroeder.
"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." ― John Muir

Are "Acts of God" Disappearing?

Considering humans' increased impact on the environment, we may want to reconsider whether there is still a place in our legal system for the Act of God defense. Thanks to all our viewers and supporters for an incredible year of videos! Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Act of God: A natural disaster that is outside of human influence or control, such that no one will be held responsible for the resulting damages. Reasonable precautions: The ordinary or usual precautions that a person would take to prevent damage from a natural disaster. ___________________________________________ If you liked this week’s video, you might also like: Learn about some of the damage done in the flood of 1903: https://www.kshs.org/kansapedia/flood-of-1903/17221 _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Melissa Hayes Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Jessika Raisor Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Alex Reich, Ever Salazar, Emily Elert, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Merritt Creamery Co. v. Atchison, T. & S. F. Ry. Co., 122 S.W. 322, 139 Mo. App. 149 (Mo. App., 1909). Herring, S. C., A. Hoell, M. P. Hoerling, J. P. Kossin, C. J. Schreck III, and P. A. Stott, Eds., 2016: Explaining Extreme Events of 2015 from a Climate Perspective. Bull. Amer. Meteor. Soc., 97 (12), S1–S145, doi:10.1175/BAMS -ExplainingExtremeEvents2015.1. Trenberth, K. E., Fasullo, J. T., & Shepherd, T. G. (2015). Attribution of climate extreme events. Nature Climate Change, 5(8), 725-730. doi:10.1038/nclimate2657. Stott, P. (2016). How climate change affects extreme weather events. Science, 352(6293), 1517-1518. doi:10.1126/science.aaf7271. Jill M. Fraley, Re-examining Acts of God, 27 Pace Envtl. L. Rev. 669 (2010) Available at: h6p://digitalcommons.pace.edu/pelr/vol27/iss3/4. Loimer, H., & Guarnieri, M. (1996). Accidents and acts of God: a history of the terms. American Journal of Public Health, 86(1), 101-107. doi:10.2105/ajph.86.1.101

2 дня назад

Why Pets Have Surprisingly Small Brains

Thanks to 23andMe for sponsoring this video! http://www.23andme.com/minuteearth If you live outside the US, click here: https://www.23andme.com/ When we domesticate an animal species, their brains shrink and they freak out less. Thanks also to our supporters on https://www.patreon.com/MinuteEarth And to our SPONSORS on YouTube. ___________________________________________ To learn more, start your googling with these keywords: Domesticated animal: a species of animal bred by humans over generations to become nonreactive and gain characteristics suitable for life as a farm animal or pet Tame animal: an individual animal raised in a way that it has become less dangerous and frightened of people Feral animal: an animal that escapes from captivity or domestication (& regains some similar & some different characteristics compared to its pre-domesticated state) "Fight or flight": an instinctive physiological response to a threatening situation that readies a creature to either to resist forcibly or escape Limbic system: the brain’s “panic button” - a system of nerves and networks near the bottom of the cortex that controls basic emotions (e.g. fear, pleasure, anger) and drives (e.g. hunger, sex, dominance) Telencephalon: the most developed and anterior part of the forebrain, consisting chiefly of the cerebral hemispheres, and the brain region that shrinks most in domesticated animals Domestication: a sustained multigenerational, mutualistic relationship in which one species (e.g. humans) assumes a significant degree of influence over the reproduction and care of another species (e.g. cows) in order to secure a more predictable supply of a resource of interest (e.g. milk/meat/traction), and through which the domesticated organisms gain advantage over individuals that remain outside this relationship (e.g. aurochs, which went extinct), thereby benefitting and often increasing the fitness of both species involved ___________________________________________ If you liked this week’s video, you might also like: Brain Scoop video on brain size and intelligence: https://www.youtube.com/watch?v=hJW8jIDfP9E Russian Fox Domestication Experiment: https://goo.gl/5nWnXz What happens to domesticated animals & their brains when they escape back to the wild?: http://www.nature.com/news/when-chickens-go-wild-1.19195#/free%5C _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Alex Reich (@alexhreich) Script Editor: Emily Elert (@eelert) Video Illustrator: Keenan Parry & Ever Salazar (@unpuntocircular) Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Kate Yoshida, Ever Salazar, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Agnvall, B. et al. 2017. Is evolution of domestication driven by tameness? A selective review with focus on chickens. Applied Animal Behaviour Science. https://doi.org/10.1016/j.applanim.2017.09.006 Eberhard, W. G., & Wcislo, W. T. 2011. Grade changes in brain-body allometry: morphological and behavioural correlates of brain size in miniature spiders, insects and other invertebrates. Advances in Insect Physiology, 40, 155. http://www.stri.si.edu/sites/publications/PDFs/2011_Eberhard_Wcislo_AdvIns_Physiol.pdf Kruska, D. C. 2005. On the evolutionary significance of encephalization in some eutherian mammals: effects of adaptive radiation, domestication, and feralization. Brain, behavior and evolution, 65(2), 73-108. https://goo.gl/J86NEd Kruska, D. C. Personal Communication, Oct 2017. Marchetti, M. P., & Nevitt, G. A. 2003. Effects of hatchery rearing on brain structures of rainbow trout, Oncorhynchus mykiss. Environmental biology of Fishes, 66(1), 9-14. https://goo.gl/GL6LWG Marchetti, M. Personal Communication, Oct 2017. Wright, D. Personal Communication, Oct 2017. Zeder, M. A. 2012. Pathways to animal domestication. Biodiversity in agriculture: Domestication, evolution and sustainability, 227-259. https://goo.gl/2xWSB8 Zeder, M. A. 2015. Core questions in domestication research. Proceedings of the National Academy of Sciences, 112(11), 3191-3198. http://www.pnas.org/content/112/11/3191.full Zeder, M. A. Personal Communication, Oct 2017.

1 неделя назад

Why Do Some Animals Get Gigantic?

Get your first KiwiCo box free by going to http://www.kiwico.com/minuteearth Occasionally, internal or external factors change, allowing certain animals to become giant versions of themselves. Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Spiracles: External respiratory openings on insects Carboniferous Period: The time period from 359-299 million years ago when the Earth’s oxygen levels increased rapidly. Square-Cube Law: A mathematical principle that describes the relationship between area and volume. Buoyancy: An upward force exerted by a fluid that opposes the weight of an immersed object. Phytoplankton: Microscopic plants eaten by krill and other zooplankton. Baleen: A filter-feeding system inside the mouth of some whales. _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Emily Elert (@eelert) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Alex Reich, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Kaiser, A., et al. (2007). Increase in tracheal investment with beetle size supports hypothesis of oxygen limitation on insect gigantism. 13198-13203. PNAS. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941816/ Sander, P. Christian, et al. (2011). Biology of the sauropod dinosaurs:the evolution of gigantism. Biological Reviews. 86(1): 117–155. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3045712/ Taylor, M and Weder, M. (2013). Why sauropods had long necks; and why giraffes have short necks. PeerJ 1:e36. Retrieved from: https://arxiv.org/pdf/1209.5439.pdf. Verberk, W. and Bilton, D. (2011). Can Oxygen Set Thermal Limits in an Insect and Drive Gigantism? PLOS One. 6(7): e22610. Retrieved from: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022610 Slater, G., Goldbogen, J., Pyenson, N. (2017). Independent evolution of baleen whale gigantism linked to Plio-Pleistocene ocean dynamics. Proceedings of the Royal Society B. 284: 20170546. Retrieved from: http://rspb.royalsocietypublishing.org/content/284/1855/20170546.

3 недели назад

What Are Brain Waves?

This video was sponsored by "Robot-Proof", written by Northeastern University's President, Joseph E. Aoun. Learn more here: https://goo.gl/uF5Kx8 Thank you to our supporters on https://www.patreon.com/MinuteEarth Even the parts of our brains that don't control physical movement show a lot of rhythm, and that might be integral to how our brains work. ___________________________________________ To learn more, start your googling with these keywords: neural oscillation: better known as a "brainwave," a neural oscillation is repetitive, often rhythmic activity in the central nervous system. neurons can sync up with the help of pacemaker cells or structure, or through entrainment. entrainment: the ability of tons and tons of neurons to quickly sync up is due to something called entrainment – here's a cool demo of essentially how that works: https://www.youtube.com/watch?v=bl2aYFv_978 central pattern generator: neural networks that produce rhythmic, patterned electrical outputs. CPGs are usually relatively simple neural circuits and are responsible for virtually all the rhythmic motions you see in nature, from jellyfish swimming to human breathing. while we often think of our brains as reaction machines – like, we touch something hot and quickly pull away – central pattern generators don't need any stimulus to work. you can pull them out of an animal and put them in a petri dish and the neurons will still fire with the same rhythms. feature binding: when you see your cat and you know right away it's your cat...well, somehow, your brain is putting together all kinds of information about the object's shape, size, color, motion, position in your field of vision, and lots of other contextual clues to make that happen. neuroscientists call this "feature binding," and neural oscillations may be key to pulling it off. _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Emily Elert (@eelert) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Emily Elert (@eelert) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Alex Reich, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder Image Credits: Snake Crawling - BigfootHD https://www.shutterstock.com/video/clip-2582720-stock-footage-snake-crawling.html Greyhound running - Objectivity https://www.youtube.com/watch?v=Iq_Oj6qzeIU Hummingbird - Smarter Every Day https://youtu.be/1VA8v1btKdQ?t=73 ___________________________________________ References: Buzsaki, G. Personal Communication, October 2017. Buzsaki, G. (2006) Rhythms of the Brain. Retrieved from https://www.researchgate.net/profile/Gyorgy_Buzsaki/publication/223130267_Rhythms_of_The_Brain/links/00b4952bb0ae609ac9000000/Rhythms-of-The-Brain.pdf Cabron, J. Personal Communcation, October 2017. Engel, A.K. and Fries, P. and Singer, W. (2001) Dynamic predictions: Oscillations and synchrony in top–down processing. Nature Reviews Neuroscience, 2, pp 704-716. Retrieved from http://www.dankalia.com/science/neu127.pdf Getting, P.A. (1989) Emerging Principles Governing the Operation of Neural Networks. Annual Review of Neuroscience. Vol. 12:185-204 Llinas, R. Personal Communication, October 2017. Lisman, J. and Buzsaki, G. (2008) A Neural Coding Scheme Formed by the Combined Function of Gamma and Theta Oscillations. Schizophrenia Bulletin, Volume 34:5, pp 974–980. Retrieved from https://academic.oup.com/schizophreniabulletin/article/34/5/974/1881304 Lisman, J. Personal Communication, October 2017. Marder, E and Calabrese, R.L. (1996) Principles of rhythmic motor pattern generation. Physiological Reviews, 76(3), pp 687-717. Retrieved from https://pdfs.semanticscholar.org/1900/8ec50b0d0bcff24438c9a0eb57f9e33f7a85.pdf Marder, E. Personal Communication, October 2017. Singer, W. Personal Communication, October 2017.

1 месяц назад

Why Bird Penises Are So Weird

Thanks to 23andMe for sponsoring this video! http://www.23andme.com/minuteearth Male birds have the largest genital diversity of any class of animals because their sex chromosomes make it easy to pass male-helping mutations down the line. Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Sex chromosome: A chromosome involved in determining the sex of an individual. Cloaca: A posterior orifice that serves as the only exit for the gastrointestinal, urinary and genital tracts. Mutation: An alteration in the DNA sequence that makes up a gene. Sexually-selected Trait: A trait based on a mutation that confers a reproductive advantage. BMP4: A protein whose presence halts the growth of bird penises in the egg. ___________________________________________ If you liked this week’s video, you might also like: An article from The Week about some of the strangest penises in the animal kingdom: http://theweek.com/articles/474417/12-weirdest-animal-penises-earth-updated _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Alex Reich, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Brennan, P. and Prum, R. (2015). Mechanisms and Evidence of Genital Coevolution: The Roles of Natural Selection,Mate Choice, and Sexual Conflict. 1-21. Cold Spring Harbor Perspectives in Biology. Retrieved from: http://cshperspectives.cshlp.org/content/7/7/a017749.abstract Brennan, P. (2013). Genital Evolution: Cock-a-Doodle-Don’t. Current Biology. R523-R525. Retrieved from: http://www.sciencedirect.com/science/article/pii/S0960982213004430 Brennan, P., Birkhead, T., Zyskowski, K., van der Waagand, J., and Prum, R. (2008). Independent evolutionary reductions of the phallus in basal birds. Journal of Avian Biology, 39: 487-492. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1111/j.0908-8857.2008.04610.x/abstract. Briskie, J. and Montgomerie, R. (1997). Sexual selection and the intromittent organ of birds. Journal of Avian Biology. 28: 73-86. Retrieved from: https://www.jstor.org/stable/3677097?seq=1#page_scan_tab_contents Herrera, A., Brennan, P., and Cohn, M. (2014). Development of Avian External Genitalia: Interspecific Differences and Sexual Differentiation of the Male and Female Phallus. Sexual Development. 9: 43-52. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/25011524. Reinhold, K. (1998). Sex linkage among genes controlling sexually selected traits. Sexual Selection. 44:1-7. Retrieved from: https://link.springer.com/article/10.1007/s002650050508. Image Credits: Mandarin Ducks - Francis C. Franklin https://commons.wikimedia.org/wiki/File:Pair_of_mandarin_ducks.jpg Gorillas - Based on photo by Wikimedia user No escape https://commons.wikimedia.org/wiki/File:Gorillafamily.JPG Lake Duck Penis - Kevin McCracken (Published in Nature 2001)

1 месяц назад

Where Do Our Drugs Come From?

The incredible chemical weapon-making abilities of fungi, bacteria, and plants have created a diverse array of compounds that are useful to humans. Thanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/ Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Bioprospecting: the systematic search for and development of new sources of chemical compounds, genes, micro-organisms, macro-organisms, and other valuable products from nature ___________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Kate Yoshida (@KateYoshida) Script Editor: Emily Elert (@eelert) Video Illustrator: Jesse Agar Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Alex Reich, Ever Salazar, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Bills, G.F. and Gloer, J.B. (2016) Biologically Active Secondary Metabolites from the Fungi. Microbiology Spectrum 4(6): 6 Cragg, G.M. and Newman, D.J. (2005) Biodiversity: A continuing source of novel drug leads. Pure and Appled Chemistry 77: 7–24 Mazid, M., Khan, T.A. and Mohammad, F. (2011) Role of secondary metabolites in defense mechanisms of plants. Biology and Medicine 3(2): 232–249. Newman, D.J. and Cragg, G.M. (2016) Natural Products as Sources of New Drugs from 1981 to 2014. Journal of Natural Products 79: 629-661 O’Brien, J. and Wright, G.D. (2011) An ecological perspective of microbial secondary metabolism. Current Opinion in Biotechnology 22:552–558

2 месяца назад

Why Do Female Hyenas Have Pseudo-Penises?!

Female hyenas don't have penises, but it sure looks like they do - and we still aren't quite sure why. To start using Tab for a Cause, go to: http://tabforacause.org/r/minuteearth2 Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Pseudopenis: a structure that resembles a penis but is developmentally (and functionally) different Masculinization: the process by which female genitalia is made to appear more like male genitalia ___________________________________________ If you liked this week’s video, you might also like: Why It Sucks to Be a Male Hyena https://www.youtube.com/watch?v=PBCNWmU5apE Hyena having a baby at the Buffalo Zoo https://www.youtube.com/watch?v=7rd7TvoPtWM _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Kate Yoshida (@KateYoshida) Script Editor: Alex Reich (@alexhreich) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Emily Elert, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder Video Credits: Spotted Hyenas Mating - Olivia Spagnuolo Image Credits: Female Spotted Hyena - Kate Yoshida Spotted Hyena Pseudopenis - Kay Holekamp Striped Hyena (Hyaena hyaena) - Flickr user Jean https://www.flickr.com/photos/7326810@N08/3091611374 Brown Hyena (Parahyaena brunnea) - Bernard DUPONT https://www.flickr.com/photos/berniedup/6472940707/ Proteles cristatus - Dominik Käuferle https://commons.wikimedia.org/wiki/File:Proteles_cristatus1.jpg Squirrel monkey - Wikimedia user Megapixie https://commons.wikimedia.org/wiki/File:Squirrel_monkey-_fuji.jpg Ring tailed lemur - Wikimedia user Sannse https://commons.wikimedia.org/wiki/File:Ring_tailed_lemur_and_twins.jpg Fossa - Ran Kirlian https://commons.wikimedia.org/wiki/File:Cryptoprocta_Ferox.JPG Binturong - Tassilo Rau https://commons.wikimedia.org/wiki/File:Binturong_in_Overloon.jpg ___________________________________________ References: Cunha GR, Risbridger G, Wang H, Place NJ, Grumbach M, Cunha TJ, Weldele M, Conley AJ, Barcellos D, Agarwal S, Bhargava A, Drea C, Hammond GL, Siiteri P, Coscia EM, McPhaul MJ, Baskin LS, Glickman SE. (2014) Development of the external genitalia: perspectives from the spotted hyena (Crocuta crocuta). Differentiation. 87(1-2):4-22. http://www.sciencedirect.com/science/article/pii/S030146811300087X?via%3Dihub Frank LG (1997) Evolution of genital masculinization: why do female hyenas have such a large 'penis'? Trends Ecol. Evol. 12:58-62. http://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(96)10063-X Frank LG and Glickman SE (1994) Giving birth through a penile clitoris: parturition and dystocia in the spotted hyaena (Crocuta crocuta). J. Zool. 234:659–665. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1994.tb04871.x/abstract Frank LG, Weldele ML, and Glickman SE (1995) Masculinization costs in hyaenas. Nature 377:584–585. http://www.nature.com/nature/journal/v377/n6550/abs/377584b0.html?foxtrotcallback=true Glickman SE, Cunha GR, Drea CM, Conley AJ and Place NJ (2006) Mammalian sexual differentiation: lessons from the spotted hyena. rends in Endocrinology and Metabolism 17 (9): 349–356. http://www.sciencedirect.com/science/article/pii/S1043276006001767 Holekamp, KE, personal communication. August and September 2017. Muller MN and Wrangham R (2002) Sexual Mimicry in Hyenas. The Quarterly Review of Biology 77 (1):3-16. http://www.journals.uchicago.edu/doi/abs/10.1086/339199?journalCode=qrb

2 месяца назад

Why Farming is Broken

Thanks to the Land Institute for sponsoring this video! To learn more about their work, visit https://landinstitute.org/ To feed everyone in the future, we may need to disrupt 10,000 years of farming practices and turn agriculture into a closed system. Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Annual plant: living for a year or less, perpetuating itself by seed Perennial plant: living for several years Polyculture: the simultaneous cultivation or exploitation of several crops or kinds of animals Natural systems agriculture: cropping systems based on processes found in nature Agroforestry: land use management that combines the cultivation of trees/shrubs with crops/pasture to create more productive and sustainable land-use systems Alley cropping: planting agricultural crops between rows of trees or shrubs ___________________________________________ If you liked this week’s video, you might also like: Alley cropping: https://nac.unl.edu/documents/agroforestrynotes/an12ac01.pdf Agroforestry: http://www.fao.org/forestry/agroforestry/89997/en/ _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Alex Reich (@alexhreich) Script Editor: Emily Elert (@eelert) Video Illustrator: Jesse Agar Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Ever Salazar, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Baker, B. 2017. Can Modern Agriculture Be Sustainable? Perennial polyculture holds promise. BioScience, 67(4), 325-331. https://doi.org/10.1093/biosci/bix018 Crews, T. E. 2016. Closing the Gap between Grasslands and Grain Agriculture. Kan. JL & Pub. Pol'y, 26, 274. https://goo.gl/d7BGsb Dawson, C. J., & Hilton, J. 2011. Fertiliser availability in a resource-limited world: Production and recycling of nitrogen and phosphorus. Food Policy, 36, S14-S22. https://goo.gl/8dMuP1 Famiglietti, J. S. 2014. The global groundwater crisis. Nature Climate Change, 4(11), 945-948. http://aquadoc.typepad.com/files/jfam_global_gw_crisis.pdf Kantar, M. B. et al. 2016. Perennial grain and oilseed crops. Annual review of plant biology, 67, 703-729. http://www.annualreviews.org/doi/abs/10.1146/annurev-arplant-043015-112311 Montgomery, D. R. (2007). Soil erosion and agricultural sustainability. Proceedings of the National Academy of Sciences, 104(33), 13268-13272. http://goo.gl/Si9E6g

2 месяца назад

Why Is Your Grandma So Short?

Learn more about the Goalkeepers report from the Bill and Melinda Gates Foundation here: http://gates.ly/2fb6CNH Nutrition during the first few years of life has a huge impact on adult height, and since nutrition has been getting better over time, humanity - including your family - is getting taller. Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ To learn more, start your googling with these keywords: Osteoporosis: Condition in which bones lose density and break down. Stunting: Impaired growth and development that children experience from poor nutrition. Malabsorption: Condition in which the intestine can’t absorb enough nutrients and fluids. Food insecurity: Lacking reliable access to sufficient and nutritious food. ___________________________________________ If you liked this week’s video, you might also like: More info on the Global Goals for Sustainable Development: http://www.globalgoals.org/#the-goals _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Alex Reich (@alexhreich) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Kate Yoshida, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: World Health Organization (2014). WHA Global Nutrition Targets 2025: Stunting Policy Brief. 1-10. Retrieved from: http://www.who.int/nutrition/topics/globaltargets_stunting_policybrief.pdf Caulfield, L., Richard, S., Rivera, J., Musgrove, P. and Black, R. (2006). Stunting, Wasting, and Micronutrient Deficiency Disorders. Disease Control Priorities in Developing Countries. 551-570. Retrieved from: https://www.ncbi.nlm.nih.gov/books/NBK11761/ NCD Risk Factor Collaboration. (2016). A Century of Trends in Adult Human Height. eLife. Retrieved from: https://elifesciences.org/articles/13410 Kang, H., Kreuels, B., Adjei, O., Krumkamp, R., May, J., and Small, D. (2013). The Causal Effect Of Malaria On Stunting: A Mendelian Randomization And Matching Approach. International Journal of Epidemiology. 42:1390–1398. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23925429 Sorkin, J., Muller, G., and Andres, R. (1999) Longitudinal Change in Height of Men and Women: Implications for Interpretation of the Body Mass Index. American Journal of Epidemiology. 150: 969-977. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/10547143

2 месяца назад

Why Do India And China Have So Many People?

Please subscribe! http://goo.gl/EpIDGd And support us on Patreon: https://www.patreon.com/MinuteEarth India and China have so many people today because they’re good for farming and big, but they’ve always been that way, so they’ve actually had a huge proportion of Earth’s people for thousands of years. Thanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/ ___________________________________________ If you liked this week’s video, you might also like: A very detailed map of world population density: https://populationexplorer.com/ Info about world population growth: https://ourworldindata.org/world-population-growth/ _________________________________________ Visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Alex Reich (@alexhreich) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Qingyang Chen (@QCVisual) Video Director: Emily Elert (@eelert) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Ever Salazar, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Eraly, A., Khan, Y., Michell, G. & Saran, M. 2008. India. DK Publishing, New York. Gidwani, V.K., April 2017, personal communication. Goldewijk, K.K., Beusen, A., & Janssen, P. 2010. Long-term dynamic modeling of global population and built-up area in a spatially explicit way: HYDE 3.1. The Holocene, 20(4), 565-573. https://goo.gl/BuwJLQ Goldewijk, K.K., Arthur Beusen, Jonathan Doelman, and Elke Stehfest. "New anthropogenic land use estimates for the Holocene; HYDE 3.2.” Unpublished manuscript. https://goo.gl/z73PNr Goldewijk, K.K., April 2017, personal communication. Maddison, A. 2006. The World Economy: A Millennial Perspective. OECD. https://www.stat.berkeley.edu/~aldous/157/Papers/world_economy.pdf Roberts, E., March 2017, personal communication. Ruggles, S., March 2017, personal communication. Stearns, P. N. (Ed.). 2001. The encyclopedia of world history: Ancient, Medieval, and Modern, chronologically arranged. Houghton Mifflin. Chicago. Thanks also to Deepak Ray, Jamie Gerber, Emily Cassidy, and Ryan Loomis.

3 месяца назад

Why Is Syrup Sticky?

Give Blinkist a try! https://www.blinkist.com/MinuteEarth What exactly makes sugary syrups so sticky, when neither water nor sugar is very sticky on its own? Support MinuteEarth on Patreon: http://www.patreon.com/minuteearth ___________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: Emily Elert (@eelert) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Jesse Agar Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Alex Reich, Henry Reich, Peter Reich, David Goldenberg, Ever Salazar Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Brown, T.L, LeMay, H.E., Bursten, B.E. (2006). Chapter 11: Intermolecular Forces, Liquids, and Solids. In Chemistry, The Central Science 10th edition. Retrieved from: http://alpha.chem.umb.edu/chemistry/ch115/Mridula/CHEM%20116/documents/chapter_11au.pdf Elert, M., Personal Communication, July 2017. Husband, T. (2014). The Sweet Science of Candymaking. Retrieved from: https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/archive-2014-2015/candymaking.html Longinotti, M.P. & Corti, H.R. (2008) Viscosity of concentrated sucrose and trehalose aqueous solutions including the supercooled regime. Journal of Physical and Chemical Reference Data, 37: 1503-1516. Molinero, V., Cagin, T., Goddard, W.A. (2003) Sugar, water and free volume networks in concentrated sucrose solutions. Chemical Physics Letters, 377:469–474. Retrieved from: https://pdfs.semanticscholar.org/8b49/ce63d9430af305c87c1dadfa0ec9bc646461.pdf Wang, L.P., Personal Communication, February 2017. Xia, J., & Case, D. A. (2012). Sucrose in Aqueous Solution Revisited: 1. Molecular Dynamics Simulations and Direct and Indirect Dipolar Coupling Analysis. Biopolymers, 97(5), 276–288. http://doi.org/10.1002/bip.22017 ___________________________________________ Image Credits: Sugar - Melissa Wiese https://www.flickr.com/photos/42dreams/2452033439/ Sugar beet field - Gilles San Martin https://www.flickr.com/photos/sanmartin/4799481326/ Sugar Cubes - David Pacey https://www.flickr.com/photos/63723146@N08/7164573186/

3 месяца назад

Our Definition For “Moon” Is Broken (Collab. w/ MinutePhysics)

Watch Henry’s MinutePhysics video: https://www.youtube.com/watch?v=NucdlR9EGbA MinuteEarth & MinutePhysics are on Patreon: http://www.patreon.com/minuteearth & http://www.patreon.com/minutephysics It’s becoming harder and harder to categorize moons as moons. ___________________________________________ To learn more, start your googling with these keywords: Moon: a natural satellite of a satellite of a star. Satellite: A celestial body orbiting a larger celestial body. Orbit: The path followed by one object revolving around another object under the influence of gravity. Barycenter: The center of mass that two or more bodies orbit around. Binary System: A system in which two similarly sized object orbit the same barycenter. Hydrostatic equilibrium: Roundness that occurs when gravity is balanced by a pressure gradient force. ___________________________________________ If you liked this week’s video, you might also like: That’s no moon … it’s a space station! https://www.youtube.com/watch?v=JGp_5gOww0E. And here's a tidy illustrated difference between geocentrism and heliocentrism: http://www.malinc.se/math/trigonometry/geocentrismen.php And MinuteLabs interactive chaotic planet orbit simulation: http://labs.minutelabs.io/Chaotic-Planets/ _________________________________________ Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Say hello on Facebook: http://goo.gl/FpAvo6 And Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Henry Reich (@MinutePhysics) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Henry Reich (@MinutePhysics) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Alex Reich, Emily Elert, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder ___________________________________________ References: Norton, J. (2008) Could a moon have moons? Popular Science. Retrieved from: http://www.popsci.com/scitech/article/2008-04/could-moon-have-moons H. A. Weaver, S. A. Stern, M. J. Mutchler, A. J. Steffl, M. W. Buie, W. J. Merline, J. R. Spencer, E. F. Young, L. A. Young (2006). The Discovery of Two New Satellites of Pluto. Nature. 439: 943-945. Retrieved from: http://www.nature.com/nature/journal/v439/n7079/abs/nature04547.html?foxtrotcallback=true Tiscareno, M., Burns, J., Sremcevi, M., Beurle, K., Hedman, M. Copper, N., Milano, A., Evans, M., Porco, C., Spitale, J., and WEiss, J. (2010) Physical Characteristics And Non-Keplerian Orbital Motion Of “Propeller” Moons Embedded In Saturn’s Rings. The Astrophysical Journal Letters, 718: 92-96. Retrieved from: http://iopscience.iop.org/article/10.1088/2041-8205/718/2/L92 Spahn, F., and Schmidt, J. (2006) Saturn’s Bared Mini-Moons. Nature, 440: 30-31. Retrieved from: https://www.nature.com/nature/journal/v440/n7084/full/440614a.html

4 месяца назад

UPSIDE-DOWN Rivers On Mars?! (Response to MinutePhysics)

Get your FREE 2-month Skillshare trial: http://skl.sh/minuteearth2 The "Mountain or Valley?" illusion makes our brains turn valleys inside out. But inside-out valleys are a real thing, both on Earth and on Mars. Thanks to Skillshare for sponsoring this video, and to our supporters on https://www.patreon.com/MinuteEarth Watch: The "Mountain Or Valley?" Illusion by MinutePhysics https://www.youtube.com/watch?v=V7C318DGB38 ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Inverted relief: a topographic feature, such as an old riverbed, that has reversed its elevation relative to other features. Duricrust: a hard mineral crust formed at or near the surface of soil in semiarid regions by the evaporation of groundwater. Geomorphology: the study of the physical features of the surface of the earth and their relation to its geological structures. Exhumed paleochannel: a remnant of an inactive river or stream channel that has been either filled or buried by younger sediment, and then subsequently uncovered by erosion. Erosion: the action of surface processes, including wind and water, that move dirt and rock from their original location to some other place. Capillary action: the tendency of a liquid in a capillary tube or absorbent material to rise or fall as a result of surface tension. Mineral precipitation: when dissolved compounds in a solution bond together to form a solid (a simple example is how dissolved sodium and chloride ions come together to form salt as water evaporates) ___________________________________________ Credits (and Twitter handles): Script Writers: David Goldenberg (@dgoldenberg) & Emily Elert (@eelert) Video Illustrator: Ever Salazar (@eversalazar) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Alex Reich, Kate Yoshida, Emily Elert, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder Image Credits: Yardangs and Ridges of the Edge of Aeolis Planum - NASA JPL University of Arizona https://hirise.lpl.arizona.edu/PSP_006683_1740 Raised Footprints - Alan Light https://www.flickr.com/photos/alan_light/5904493388/ _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ The inverted relief at the end of the video is at Green River, Utah https://www.google.com/maps/@38.8744077,-110.2558884,867m/data=!3m1!1e3 ___________________________________________ References: Clarke, J., July 2016, personal communication. Clarke, J. D., & Stoker, C. R. (2011). Concretions in exhumed and inverted channels near Hanksville Utah: implications for Mars. International Journal of Astrobiology, 10(03), 161-175. doi:10.1017/s1473550411000048 Harris, D.R. (1980). Exhumed paleochannels in the Lower Cretaceous Cedar Mountain formation near Green river. Utah: Brigham Young Univ. Geol. Stud. 27, 51–66. Malin, M. C. (2003). Evidence for Persistent Flow and Aqueous Sedimentation on Early Mars. Science, 302(5652), 1931-1934. doi:10.1126/science.1090544 Miller, R. P. (1937). Drainage Lines in Bas-Relief. The Journal of Geology, 45(4), 432-438. doi:10.1086/624550 Pain, C.P & Ollier, C.D. (1996). Regolith stratigraphy: principles and problems. Journal of Australian Geology & Geophysics, 16(3), 197-202. Pain, C., Clarke, J., & Thomas, M. (2007). Inversion of relief on Mars. Icarus, 190(2), 478-491. doi:10.1016/j.icarus.2007.03.017 Pain, C., July 2016, personal communication.

4 месяца назад

TRANSPARENT Solar Panels?!

Infinitesimally small quantum dots can turn a window into a see-through solar panel! Thanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/ Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Solar window: a window that functions like an ordinary window but also generates power like a solar panel Nanoparticle (also called nanopowder or nanocluster or nanocrystal): a microscopic particle with at least one dimension less than 100 nm. These tiny objects often have characteristics that differ from larger versions of the same material. Quantum dots (QD): tiny nanoparticles of some kind of semiconducting material, only several nanometers in size, so small that their optical and electronic properties differ from those of larger particles. The QDs embedded in solar windows can absorb radiation largely in short wavelengths and re-emit in longer wavelengths; useful for capturing solar energy and successfully transferring it to the solar cells on the edges of the pane. Total internal reflection: a phenomenon in which a wave hits a medium boundary at such an angle that it doesn't pass through to the other side ___________________________________________ Credits (and Twitter handles): Script Writers: Peter Reich & Emily Elert Script Editor: Alex Reich (@alexhreich) Video Illustrator: Qingyang Chen (@QCVisual) Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Ever Salazar, Emily Elert, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder Image Credits: Thumbnail: R. Lunt, MSU. _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ References: Bradshaw, L. R., Knowles, K. E., McDowall, S. & Gamelin, D. R. Nanocrystals for luminescent solar concentrators. Nano Lett. 15, 1315–1323 (2015). Meinardi, F., Ehrenberg, S., Dhamo, L., Carulli, F., Mauri, M., Bruni, F., Simonutti, R., Kortshagen, U. and Brovelli, S., 2017. Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots. Nature Photonics, 11(3), pp.177-185. Meinardi, F. et al. Highly efficient large-area colourless luminescent solar concentrators using heavy-metal-free colloidal quantum dots. Nat. Nanotech.10, 878–885 (2015). Yang, C, R. R. Lunt. Limits of Visibly Transparent Luminescent Solar Concentrators. Adv. Opt. Mat., 5, 8, 1600851, 2017. Zhao Y., G. Meek, B. Levine, and R. R. Lunt, “Near-Infrared Harvesting Transparent Luminescent Solar Concentrators”. Adv. Opt. Mat., 2, 606, 2014.

4 месяца назад

Why It Sucks to Be a Male Hyena

Thanks to spotted hyenas’ unusual social structure, males experience a tough life of solitude, harassment, and deprivation. Support us on Patreon to see more videos like this: https://www.patreon.com/minuteearth/posts Thank you to our current supporters on https://www.patreon.com/MinuteEarth Watch our Q&A from 7/21/17: https://www.patreon.com/posts/friday-q-with-13099025 ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Sex role reversed species: a species in which males and females exhibit roles other than what might be expected based on other aspects of their biology and mating systems ___________________________________________ Credits (and Twitter handles): Script Writer: Kate Yoshida (@KateYoshida) Script Editor: Emily Elert (@eelert) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Alex Reich, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder Video Credits: Hyenas feeding - Kate Yoshida Image Credits: Scarface - Kate Yoshida _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ If you liked this week’s video, we think you might also like: A blog by researchers currently studying spotted hyenas in Kenya's Masai Mara: http://msuhyenas.blogspot.com/ ___________________________________________ References: Chepko-Sade, B. D. & Z. T. Halpin. 1987. Mammalian dispersal patterns: the effects of social stucture on population genetics. University of Chicago Press. Chicago, Illinois. Holekamp, K.E. & Smale, L. (2000) Feisty females and meek males: reproductive strategies in the spotted hyena. In Reproduction in Context. K. Wallen and J. Schneider (Eds). MIT Press. Cambridge. MA. Pp. 257-285. Kruuk H. 1972. The spotted hyena: a study of predation and social behavior. Chicago: University of Chicago Press. Smale, L., Nunes, S., and Holekamp, K.E. (1997) Sexually dimorphic dispersal in mammals: patterns, causes and consequences. Advances in the Study of Behavior 26: 181-250. Strauss, E., February 2017, personal communication. Turner, J., June 2017, personal communication. Van Horn, R.C., McElhinny, T.L. & Holekamp, K. E. (2003) Age estimation and dispersal in the spotted hyena (Crocuta crocuta). Journal of Mammalogy 84: 1019-1030. Watts, H. E. & Holekamp, K. E. (2007) Hyena societies. Current Biology 17: R657-R660.

4 месяца назад

Invasion Of The Earthworms!

Worms cause major changes to ecosystems, but those changes aren’t always new. Thanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/ Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Invasive species: A non-native species that causes harm to the ecosystem. Biome: A large, naturally occurring community of flora and fauna. Duff layer: The moderately to highly decomposed organic material between the leaf litter and the soil. Seedling: A young plant less than one meter high. Sapling: A young tree that’s bigger than a seedling. Graminoids: Herbaceous plants and grasses. Coevolution: The process that occurs when two closely associated species influence each other’s evolutionary paths. Savanna: A grassy plain with scattered tree coverage. ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Alex Reich (@alexhreich) Video Illustrator: Qingyang Chen (@QCVisual) Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Kate Yoshida, Ever Salazar, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ ___________________________________________ References: Dylan Craven, Madhav P. Thakur, Erin K. Cameron, Lee E. Frelich, Robin Beauséjour, Robert B. Blair, Bernd Blossey, James Burtis, Amy Choi, Andrea Dávalos, Timothy J. Fahey, Nicholas A. Fisichelli, Kevin Gibson, I. Tanya Handa, Kristine Hopfensperger, Scott R. Loss, Victoria Nuzzo, John C. Maerz, Tara Sackett, Bryant C. Scharenbroch, Sandy M. Smith, Mark Vellend, Lauren G. Umek, Nico Eisenhauer (2016). The unseen invaders: introduced earthworms as drivers of change in plant communities in North American forests (a meta-analysis). Global Change Biology. 1-10. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1111/gcb.13446/full Sonja Migge-Kleian, Mary Ann McLean, John C. Maerz, and Liam Heneghan (2006). The influence of invasive earthworms on indigenous fauna in ecosystems previously uninhabited by earthworms. Biological Invasions. 8:6 (1275-1285). Retrieved from: https://link.springer.com/article/10.1007/s10530-006-9021-9 Alexander M.Roth, Timothy J.S.Whitfeld, Alexandra G. Lodge, Nico Eisenhauer, Lee E. Frelich· and Peter B. Reich (2015). Invasive earthworms interact with abiotic conditions to influence the invasion of common buckthorn (Rhamnus cathartica). Oecologia. 178: 219:230. Retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/25481818 Hendrit, Paul (Editor). 2007. Biological Invasions Belowground: Earthworms as Invasive Species. Wackett, Adrian. (2017). Department of Soil, Water, and Climate, University of Minnesota. Personal Communication.

5 месяцев назад

Why So Many Meteorites Come From The Same Place

Because of space physics, one faraway asteroid is likely the progenitor of almost a third of all the meteorites on Earth. Thanks to Skillshare for sponsoring this video: http://skl.sh/MinuteEarth Jorge and Daniel's awesome new book, "We Have No Idea": https://www.amazon.com/We-Have-No-Idea-Universe/dp/0735211515 Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Asteroid: A rocky body smaller than a planet that is orbiting the sun. Meteoroid: A smaller rocky body moving in the solar system. Meteor: A meteoroid that has entered the Earth’s atmosphere. Meteorite: A meteor that hits the Earth. Orbital resonance: A force that occurs when orbiting bodies exert a regular, periodic gravitational influence on each other, because of the length of their relative orbits. Kirkwood Gap: A dip in the distribution of main belt asteroids that correspond to the locations of orbital resonances with Jupiter. ___________________________________________ Credits (and Twitter handles): Script Writer: David Goldenberg (@dgoldenberg) Script Editor: Alex Reich Video Illustrator: Jorge Video Director: Emily Elert (@eelert) Video Narrator: Emily Elert (@eelert) With Contributions From: Henry Reich, Kate Yoshida, Ever Salazar, Peter Reich Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our website: https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And download our videos on itunes: https://goo.gl/sfwS6n ___________________________________________ If you liked this week’s video, we think you might also like: A terrifying but fascinating look at the destructive power of potential meteorites: http://www.purdue.edu/impactearth/ ___________________________________________ References: Burbine, T., McCoy, T., Meibom, A., Royer, C., Gladman, B., and Keil, K. (2002). Meteoritic Parent Bodies: Their Number and Identification. Asteroids III. 653-667. Retrieved from: http://adsabs.harvard.edu/abs/2002aste.book..653B Farinella, P., Gonczi, R., Froeschle, Ch., and Froeschle, C. (1993). The Injection of Asteroid Fragments into Resonances. Icarus. 101: 174-187. Retrieved from: http://www.sciencedirect.com/science/article/pii/S001910358371016X Fieber-Beyer, S., Gaffey, M., Bottke, W., and Hardersen, P. (2015). Potentially hazardous Asteroid 2007 LE: Compositional link to the black chondrite Rose City and Asteroid (6) Hebe. Icarus. 250: 430-437. Retrieved from: http://www.sciencedirect.com/science/article/pii/S0019103514007088 Gaffey, M. and Gilbert, S. (1998). Asteroid 6 Hebe: The probable parent body of the H-type ordinary chondrites and the IIE iron meteorites. Meteoritics and Planetary Science. 33: 1281-1295. Retrieved from: http://onlinelibrary.wiley.com/doi/10.1111/j.1945-5100.1998.tb01312.x/abstract Vokrouhlicky, D., and Farinella, P. (2000). Efficient delivery of meteorites to the Earth from a wide range of asteroid parent bodies. Nature. 407: 606-608. Retrieved from: https://www.nature.com/nature/journal/v407/n6804/full/407606a0.html Moons, M. and Morbidelli, A. (1995). Secular Resonances in Mean Motion Commensurabilities: The 4/1, 3/1, 5/2, and 7/3 Cases. Icarus. 114: 33-50. Retrieved from: http://www.sciencedirect.com/science/article/pii/S001910358571041X Burbine, Thomas. (2017). Assistant Professor of Astronomy, University of Massachusetts. Personal Communication.

5 месяцев назад

What Nuclear Bombs Taught Us About Whales

A monitoring system developed to listen for secret nuclear tests mostly hears other events happening all around Earth. Thanks to CTBTO for sponsoring this video: https://www.ctbto.org/ Thanks also to our supporters on https://www.patreon.com/MinuteEarth Visit our NEW WEBSITE: https://www.minuteearth.com/ ___________________________________________ If you want to learn more about this topic, start your googling with these keywords: Infrasound: sound waves too low in frequency for humans to hear. The CTBTO stations detect frequencies of 0.02 to 4Hz Hydroacoustic: having to do with underwater sounds. The CTBTO stations detect frequencies of 1-100 Hz Seismic: oscillation waves in the earth, often caused by earthquakes or other tectonic activity. The CTBTO stations detect frequencies of 0.02-16 Hz ___________________________________________ Credits (and Twitter handles): Script Writer: Alex Reich Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Jesse Agar Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Ever Salazar, Emily Elert, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And find us on itunes: https://goo.gl/sfwS6n ___________________________________________ If you liked this week’s video, we think you might also like: Animals can detect infrasound: http://www.slate.com/articles/news_and_politics/explainer/2004/12/surviving_the_tsunami.html A Time-Lapse Map of Every Nuclear Explosion Since 1945: https://www.youtube.com/watch?v=LLCF7vPanrY Sound travels 1000s of miles in the ocean’s SOFAR channel: https://en.wikipedia.org/wiki/SOFAR_channel ___________________________________________ Sounds in the video that were recorded by CTBTO stations: 0:32 Kasatoshi volcano eruption in August 2008, detected 2100km away at infrasound station on mainland Alaska. Sped up 500x https://en.wikipedia.org/wiki/Kasatochi_Island 0:35 Explosion of Antares rocket in October 2014, detected 1100km away at Bermuda infrasound station. Sped up 150x https://en.wikipedia.org/wiki/Cygnus_CRS_Orb-3 and video: https://en.wikipedia.org/wiki/File:Antares_Fails_to_Reach_Orbit_with_Cygnus_CRS-3_after_Rocket_Explodes.webm 0:37 Ship engine detected June 1 2017 by hydroacoustic station. Sped up 16x 0:40 Waves hitting an iceberg and causing it to vibrate like a cymbal in July 2010. Detected by hydroacoustic station off of Western Australia. Sped up 16x 1:01 Whale call Feb 18 2017, detected by hydroacoustic station. Sped up 16x 1:08 Chelyabinsk meteor airburst February 15 2013, detected by infrasound station 650km away in Kazakhstan. Sped up 135x 1:39 Earthquake Jan 2 2017, detected by infrasound station. Sped up 16x 2:00 Sound with unknown cause, detected by hydroacoustic station. March 25 2017. Sped up 16x References Brown, P. G., et al. 2013. A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors. Nature, 503(7475), 238-241. http://dx.doi.org/10.1038/nature12741 Gavrilov, A. May 2017, Personal communication Graham, G. May 2017, Personal communication Harabalus, G. May 2017, personal communication LeBras, R. May 2017, personal communication Mialle P., May 2017, personal communication Miksis-Old, J. May 2017, personal communication Nielsen, P., May 2017, personal communication Le Pichon, A., et al. 2013. The 2013 Russian fireball largest ever detected by CTBTO infrasound sensors. Geophysical Research Letters, 40(14), 3732-3737. http://onlinelibrary.wiley.com/doi/10.1002/grl.50619/full

5 месяцев назад

Why Does Wine Make Your Mouth Feel Dry?

Check out our new website! https://www.minuteearth.com/ Thanks to Squarespace for sponsoring this video. http://www.squarespace.com/minuteearth Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ Astringent plant chemicals called tannins bind proteins on mucous membrane and skin, generating a prickly, puckery mouthfeel from foods and letting us “tan” skins into leather. ___________________________________________ If you want to learn more about this topic, start your googling here: Tannin: a yellow or brownish chemical present in some plant tissues, used in leather production and ink manufacture, and a contributor to the sensation of astringency Astringency: the sensation caused by the contraction of body tissues due to tannins, often called “mouthfeel” Polyphenol: a chemical compound containing more than one phenolic hydroxyl group, of which tannins are a major group Phenolic: a chemical compound with a hydroxyl group (oxygen & hydrogen) linked directly to a benzene ring ___________________________________________ Credits (and Twitter handles): Script Writer: Alex Reich (@alexhreich) Script Editor: Kate Yoshida (@KateYoshida) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Henry Reich (@MinutePhysics) Video Narrator: Emily Elert (@eelert) With Contributions From: Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ And visit our new website! https://www.minuteearth.com/ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And find us on itunes: https://goo.gl/sfwS6n ___________________________________________ References: Bajec, M. R., & Pickering, G. J. 2008. Astringency: mechanisms and perception. Critical reviews in food science and nutrition, 48(9), 858-875. https://goo.gl/XLR0JY Barbehenn, R. V., & Constabel, C. P. 2011. Tannins in plant–herbivore interactions. Phytochemistry, 72(13), 1551-1565. http://www.sciencedirect.com/science/article/pii/S0031942211000690 Covington, A. D. 1997. Modern tanning chemistry. Chemical Society Reviews, 26(2), 111-126. http://pubs.rsc.org/en/content/articlehtml/1997/cs/cs9972600111 Covington, A. D. 2009. Tanning chemistry: the science of leather. Royal Society of Chemistry. Covington, A., Mar 2017, personal communication. Gawel, R. 1998. Red wine astringency: a review. Australian Journal of Grape and Wine Research, 4(2), 74-95. http://onlinelibrary.wiley.com/doi/10.1111/j.1755-0238.1998.tb00137.x/full Lesschaeve, I. & A.C. Noble. 2005. Polyphenols: factors influencing their sensory properties and their effects on food and beverage preferences. The American journal of clinical nutrition 81, no. 1: 330S-335S. http://ajcn.nutrition.org/content/81/1/330S.full McGee, H. 2004. On food and cooking: the science and lore of the kitchen. Simon and Schuster. Siebert, K., Mar 2017, personal communication.

6 месяцев назад

This Is Not A Bee

Thanks to Dollar Shave Club for sponsoring this video. Get your first month of the Executive Razor with Dr. Carver’s Shave Butter for only $5 at http://www.dollarshaveclub.com/minuteearth It can be hard to distinguish bees from all the other insects out there that look like bees. Thanks also to our supporters on https://www.patreon.com/MinuteEarth ___________________________________________ If you want to learn more about this topic, start your googling here: Mullerian mimicry: a type of mimicry in which two or more animals with defenses develop similar appearances as a shared protective device Batesian mimicry: a type of mimicry in which an animal with no defenses is protected by its resemblance to an animal capable of defense ___________________________________________ Credits (and Twitter handles): Script Writer: Kate Yoshida (@KateYoshida) Script Editor: Alex Reich (@alexhreich) Video Illustrator: Ever Salazar (@eversalazar) Video Director: Kate Yoshida (@KateYoshida) Video Narrator: Kate Yoshida (@KateYoshida) With Contributions From: Henry Reich, Emily Elert, Peter Reich, David Goldenberg Music by: Nathaniel Schroeder: http://www.soundcloud.com/drschroeder _________________________________________ Like our videos? Subscribe to MinuteEarth on YouTube: http://goo.gl/EpIDGd Support us on Patreon: https://goo.gl/ZVgLQZ Also, say hello on: Facebook: http://goo.gl/FpAvo6 Twitter: http://goo.gl/Y1aWVC And find us on itunes: https://goo.gl/sfwS6n ___________________________________________ If you liked this week’s video, we think you might also like: A collection of "bees" that aren't bees: http://notabee.tumblr.com/ The Psychology of Mimicry: https://www.youtube.com/watch?v=n4RJRNi-t_E ___________________________________________ References: Brower J.V.Z. & Brower L.P., (1965). Experimental studies of mimicry. 8. Further investigations of honeybees (Apis mellifera) and their dronefly mimics (Eristalis spp.). American Naturalist 99:173–187. https://www.jstor.org/stable/pdf/2459113.pdf Dyer, F., Jan 2017, personal communication. Franks, D. W. and Noble, J., (2002). The origins of mimicry rings. Standish, R. K., Bedau, M. A. and Abbass, H. A.(eds.) In Artificial Life VIII: Proceedings of the Eighth International Conference on Artificial Life. MIT Press., pp. 186-191. http://alife8.alife.org/proceedings/sub2852.pdf Pasteur, G., (1982). A classificatory review of mimicry systems. Annual Review of Ecology & Systematics, 13: 169–199. http://www.annualreviews.org/doi/abs/10.1146/annurev.es.13.110182.001125?journalCode=ecolsys.1 Rettenmeyer, C.W., (1970). Insect Mimicry. Annual Review of Entomology 15: 43-74. http://dx.doi.org/10.1146/annurev.en.15.010170.000355. Wilson, J., Jan 2017, personal communication. ___________________________________________ Image Credits: Honey bee (Apis mellifera) - Charles James Sharp https://commons.wikimedia.org/wiki/File:Honey_bee_(Apis_mellifera).jpg Sugar bag bee - Graham Wise https://en.wikipedia.org/wiki/File:Tetragonula_carbonaria_(14521993792).jpg Agapostemon virescens - Susan Ellis https://commons.wikimedia.org/wiki/File:Agapostemon_virescens.jpg Amegilla cingulata bee - Chiswick Chap https://commons.wikimedia.org/wiki/File:Amegilla_cingulata_on_long_tube_of_Acanthus_ilicifolius_flower.jpg Drone fly (Eristalis tenax) - Francis C. Franklin https://commons.wikimedia.org/wiki/File:Eristalis_tenax_and_flowers.jpg Eumeninae Wasp - Joaquim Alves Gaspar https://commons.wikimedia.org/wiki/File:Wasp_August_2007-3.jpg Sesia apiformis - Gyorgy Csoka https://commons.wikimedia.org/wiki/File:Sesia_apiformis_adult1.jpg Lunate Blister Beetle - Bernard DUPONT https://www.flickr.com/photos/berniedup/12748380493/ Plain Lacewing (Cethosia hypsea) caterpillar - Bernard Dupont https://www.flickr.com/photos/berniedup/22723162703 Nymph of Green Milkweed Locust (Phymateus viridipes) - Bernard DUPONT https://commons.wikimedia.org/wiki/File:Nymph_of_Green_Milkweed_Locust_(Phymateus_viridipes)_(13983971884).jpg Eristalis tenax - Wilder Kaiser https://commons.wikimedia.org/wiki/File:Eristalis_tenax_01Aug2009.jpg Yellow Jacket Wasp - Wikimedia user Bombman356 https://commons.wikimedia.org/wiki/File:Yellow_jacket_wasp.jpg

6 месяцев назад