ChristopherBergevinYorkUniversity,Dept.ofPhysics&AstronomyOffice:Petrie240 Lab:Farq [email protected]
PHYS1420(F19)PhysicswithApplicationstoLifeSciences
2019.09.04Relevantreading:Kesten &Tauck ch. 1.1-1.6+Polya
Wikipedia
https://nanomri.files.wordpress.com/2011/09/mri.jpg
QuestionHowmightwe“see”brain?Howit“functions”?
QuestionHowdowemakea3-Dimageofreallysmallthings(e.g.,molecularstructure)?
Franklin & Gosling (1953)
Watson & Crick (1953)
à HowdidWatsonandCrickactuallyfigureouta“doublehelix”forDNA?
CaveatEven“simple”questionscanbehard…
e.g.,Howmanymountainpeaks arethereinthisimage?
e.g.,Howmanymountainpeaks arethereinthisimage?
Etymology
§ Whatdoes“physics”evenmean?
(fromwikipedia)“Physics (fromAncient Greek:φυσική (ἐπιστήμη) phusikḗ(epistḗmē) ’knowledgeofnature’,fromφύσις phúsis "nature)….
… isthenaturalsciencethatinvolvesthestudyofmatteranditsmotionandbehaviorthroughspaceandtime,alongwithrelatedconceptssuchasenergyandforce.Oneofthemostfundamentalscientificdisciplines,themaingoalofphysicsistounderstandhowtheuniversebehaves.”
(fromMerriam-Webster)“Asciencethatdealswithmatterandenergyandtheirinteractions”
(KahnAcademy)“Tobehonest,it’sreallydifficulttodefineexactlywhatphysicsis.Forone,physicskeepschangingasweprogressandmakenewdiscoveries.”
(ourworkingPHYS1420definition) à Problemsolving
PHYS1420Logistics
PHYS1420Logistics
https://www.yorku.ca/cberge/1420F2019.html
PHYS1420Logistics
PHYS1420Course“Philosophy” (WOTversion)
1. Learnthebasicsof1styearphysicsandsomeapplicationstothelifesciences
à ”Physics"isgenerallyequatedw/abranchofcriticalinquirytryingtotrackdownthe"universalrules"thatgovernhowtheuniverseworks
2.Develop/refine"quantitativeproblemsolving"skills
à Ultimatelyanissueof"attitude"suchthatyoufeelcomfortabletackingtheunknown(asthesesortsofskillsareinvaluableandwillopendoorsforyoudownstream).byandlarge,thisinvolvesrefining/developingyourmathematical-basedreasoningskills
PHYS1420Course“Philosophy” (WOTversioncont)
Ø Areassuchasbiophysics aretwo-waystreetsinthatsuchcanbesimultaneouslyviewedasboth"physics-applied-to-biology"and"biology-motivating/informing-physics".Sophysics&biologycanbeseenasnaturallygoingtogetherhand-in-hand
Ø Byandlarge,wefollowawell-establishedcurricularpath,covering:Newtonianmechanics,conceptofenergy,circularmotion,oscillations,etc….
Ø … BUTalsoweaveinsomenoveldirections(e.g.,diffusion)
Ø Ahandfulofassociatedmathematicaltopics naturallyfalloutofthis(tovaryingdegreesofdepth):vectors,calculus(i.e.,howthings"change"),polarcoordinates,geometry,sinusoids,etc….
PHYS1420Logistics
§ Coursewebsite: http://www.yorku.ca/cberge/PHYS1420F19.html
§ Readthebook&cometoclass(&getascratchpadandnotebook)
§ Cometotutorialsandengagew/oneanother
§ DotheHW(bothwritten&online)à purposeistopracticeproblem-solving&developconfidence!
§ Alltheabovewillhelpyougetproperlypreparedforthetests
à Let’stakeastepbackforamomentandlookatsomeofthebroader“themes”thatweaimto(interdisciplinarily)weaveintothecourse.....
Etymology
§ Whatdoes“physics”evenmean?
(fromwikipedia)“Physics (fromAncient Greek:φυσική (ἐπιστήμη) phusikḗ(epistḗmē) ’knowledgeofnature’,fromφύσις phúsis "nature)….
… isthenaturalsciencethatinvolvesthestudyofmatteranditsmotionandbehaviorthroughspaceandtime,alongwithrelatedconceptssuchasenergyandforce.Oneofthemostfundamentalscientificdisciplines,themaingoalofphysicsistounderstandhowtheuniversebehaves.”
(fromMerriam-Webster)“Asciencethatdealswithmatterandenergyandtheirinteractions”
(KahnAcademy)“Tobehonest,it’sreallydifficulttodefineexactlywhatphysicsis.Forone,physicskeepschangingasweprogressandmakenewdiscoveries.”
(ourworkingPHYS1420definition) à Problemsolving
“Puzzles” – Bongard problems
Determinethe“rule”thatisdifferentbetweenthetwosides(eachofsix)
e.g.,http://www.foundalis.com/res/bps/bpidx.htm
“Puzzles” – Bongard problems
“Puzzles” – Bongard problems
Polya
Theme:Problem-solving......
Amanlivesonthetenthfloorofabuilding.Everydayhetakestheelevatortogodowntothegroundfloortogotoworkortogoshopping.Whenhereturnshetakestheelevatortotheseventhfloorandwalksupthestairstoreachhisapartmentonthetenthfloor.Whydoeshedothis?
e.g.,“classicalmechanics”
vonBaeyer
Theme:WhatisLife?
Oneresponsetothequestion,WhatisLife?issimply,LookAround!
-FrankM.Harold
à Quicktangentintohurricanes,uncertainty,and“fakenews”…
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
Note(re1420):Implicithereisthenotionofa“model”(akeyheuristiccentraltoPHYS1420)
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
https://www.clickorlando.com/weather/hurricane/updates-track-computer-models-satellite-for-hurricane-dorian
Aug.29,2019
Aside:Fakenews?
https://www.clickorlando.com/weather/hurricane/updates-track-computer-models-satellite-for-hurricane-dorian
Aside:Fakenews?
Aug.29,2019
https://www.wtnh.com/weather/hurricane-dorian-strengthens-and-shifts-now-expected-to-hit-the-carolinas-live-updates/
Sept.1,2019
Seealso:https://www.nhc.noaa.gov/archive/2019/DORIAN_graphics.php?product=5day_cone_no_line_and_wind
àWeathermodeling&predictionishighlychallenging!
https://www.nytimes.com/interactive/2019/08/29/opinion/hurricane-dorian-forecast-map.html
à Life(likeweather)isstochastic
Note: [https://en.wikipedia.org/wiki/Dorian_(name)]DorianisaunisexgivennameofGreekorigin.InGreek,themeaningofthenameDorianisofDoris,adistrictofGreece;orofDoros,alegendaryGreekhero.Doros wasthesonofHelenofSparta(whowasthedaughterofZeusandLeda).Doros wasthefounderoftheDoriantribe,andthemostlikelyoriginofDoros'namewastheGreekword"doron",meaning'gift'.
http://www.dailymail.co.uk/news/article-4833342/Islands-fire-ants-floating-Houston-floodwaters.html
IslandsofvenomousfireantcoloniesspottedfloatinginrisingfloodwatersinHouston
Theme:Notionof“information”(plustheideaofemergence fromcomplexsystems)
à Howdothey“know”(how)todothis?!
Theme:WhatisLife?(REVISTED)
http://www.thisiscolossal.com/2017/09/elements-film-maxim-zhestkov/
Theme:Bridging“micro”and“macro”-scopic scales
Human brain contains ~1011 (100 billion) neurons!(with 100 trillion+ connections inbetween)
Howmanyneuronsarethereinthehumanbrain?Synapses?
PopQuiz
Weiss (1996)
Neurons(“fibers”)=Informationhighway
KeyPoint:Electricalpropertiesofcellsareimportant
1– Basicneurosciencebuildingblocks
Aside: Neurons
Weiss (1996)
zoominoncellmembrane
insidecell
outsidecell
Ø Membraneprimarilyconsistsofa“lipidbilayer”(toseparateinsidefromoutside)
Ø Allsortsof“stuff”embeddedinside,toallowfor“communication”acrossmembrane
1– Basicneurosciencebuildingblocks
Aside: Cellmembranes
(crazyidea)Modelthecellmembraneasanelectriccircuit
AlanHodgkin AndrewHuxley
1963NobelPrize
http://www.thisiscolossal.com/2017/09/elements-film-maxim-zhestkov/
Theme(REVISTED):Bridging“micro”and“macro”-scopic scales
Theme:NeuroscienceandthebrainNote:TakeBPHS4080(CellularElectrodynamics)ifyoureallywanttodelveintothisproperly…
Note:Studyinghowstuff“moves”acrossacellmembraneisthesamebasicthingasthemoregeneral“howdoesstuffmove?”
e.g.,“classicalmechanics”
vonBaeyer
àWe’llstartdelvingintothatnextweekvia“mechanics”andeasiersortsof“stuff”tostudy
BrownianmotionÞ ‘RandomWalker’ (1-D)
EnsembleofRandomWalkers
Aside: Microscopicbasisfordiffusion
t = 0
t = 1
t = 5
t = 50
à Diffusion(forwhichBrownianmotionisthemicroscopic basis)
§ OntheMovementofSmallParticlesSuspendedinStationaryLiquidsRequiredbytheMolecular-KineticTheoryofHeat (Brownianmotion)
(side-)Theme:Computationalapproaches(i.e.,programming)
...sohowmightyou“program”acomputertosolvetheseproblems?
Yourbrain/communityis“programmed”tosolveproblems...
Mathematics of Vision Workshop
October 17-18, 2019Fields Institute, Toronto, ON Canada
∴ Website ⇒ http://www.fields.utoronto.ca/activities/19-20/vision∴ Pre-registration ⇒ https://forms.gle/k9NA82w9gTCBn67V7∴ Questions? ⇒ [email protected]
Invited Speakers
• Stephanie Palmer (U. of Chicago)
• Alexandre Pouget (U. of Geneva)
• Odelia Schwartz (U. of Miami)
• Tatyana Sharpee (UCSD, Salk Inst.)
• Lai-Sang Young (NYU)
• Richard Zemel (U. of Toronto & Vector Inst.)
Biophysics
Lennart Nilsson
