Sterrekunde

Kan ons materie deur die tyd volg deur na verskillende dieptes in die ruimte te kyk?

Kan ons materie deur die tyd volg deur na verskillende dieptes in die ruimte te kyk?


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As ons ver genoeg terugkyk, kan ons die oorsprong van die heelal sien, is dit dan moontlik, al is dit nie haalbaar nie, dat ons die geskiedenis van een of ander saak kan opspoor as dit deur die ruimtetyd beweeg? Ek wil verstaan ​​hoe kyk na verskillende dieptes in ruimte en tyd verband hou met die saak wat waargeneem word.

Sou dit byvoorbeeld moontlik wees om diep in 'n sekere deel van die ruimte en tyd te kyk om 'n sterrestelsel te vind wat bygedra het tot die saak waaruit die melkweg bestaan? Volg dit dan op een of ander manier deur ruimte-tyd deur na verskillende dieptes en plekke in die ruimte te kyk en te sien hoe dit deel van die Melkweg geword het?


Sou dit moontlik wees om diep in 'n sekere deel van die ruimte en tyd te kyk om 'n sterrestelsel te vind wat bygedra het tot die saak waaruit die melkweg bestaan?

Nee, dit is nie moontlik nie. As ons dit sou kon doen, sou dit beteken dat die saak vinniger van hier af gereis het as wat die lig hierheen gekom het, en dat materie nie vinniger deur die ruimte kan beweeg as wat die lig doen nie.

Almal ons kan doen is om vroeër tye na soortgelyke sterrestelsels as die Melkweg te kyk. En weens die uitbreiding van die ruimte is hierdie sterrestelsels nou nog verder van ons af as toe hulle die lig wat ons nou sien, uitstraal.

Sterrestelsels ontwikkel (meestal) in isolasie van mekaar, afgesien van die samesmelting of botsing tussen naburige sterrestelsels. Intergalaktiese afstande is redelik groot, dus neem materie baie tyd om van een sterrestelsel na 'n ander te beweeg, en materie word meestal deur swaartekrag gebind tot die sterrestelsel waarin dit is. Galaksiese ontsnappingssnelhede is redelik hoog, alhoewel die ster af en toe geslinger word uit die sterrestelsel deur rampspoedige gebeure soos supernova-ontploffings. Maar selfs dan beland sulke skelm liggame meestal in die intergalaktiese ruimte. Die kans dat hulle in 'n ander sterrestelsel beland, is redelik skraal.


U sal die lig moet inhaal wat die inligting bevat wat u soek. Dit het op hierdie stadium 'n paar miljard jaar gereis (die aarde is ~ 4.3B). U kan dus die vorming van die Aarde (Melkweg, wat ook al) dophou as u miljarde ligjare van hier af dadelik kan teleporteer.

As ons na sterrestelsels in die verte kyk, is dit 'ou' lig wat ons sien. Die gebeure wat ons sien, het baie jare gelede plaasgevind. As ons 'n sterrestelsel sien vorm, en daardie sterrestelsel 10 miljard ligjare weg is, het die sterrestelsel al gevorm. Die konfigurasie daarvan is tans baie anders as wat ons sien. Sommige sterre is eintlik al uitgebrand. Net so sou u die Melkweg sien soos dit 10B jaar gelede verskyn het (of dadelik na daardie sterrestelsel kon woon) (of dadelik na daardie sterrestelsel kon woon).


Om die vorming van die Melkweg te sien, het u 'n manier nodig om die fotone waar te neem wat nou ~ 5 miljard ligjaar van ons af is, waar te neem.

Een manier om dit te bewerkstellig, is om 'n spieël in die verre ruimte te vind en na ons eie weerkaatsing daarin te kyk. Die erns van swart gate kan veroorsaak dat fotone 'n volle draai maak en na ons terugkeer: https://physics.stackexchange.com/questions/225693/using-a-naked-black-hole-as-a-mirror

Met ons huidige tegnologie is dit egter steeds onuitvoerbaar, aangesien die klein hoeveelheid fotone uit ons weerkaatsing verlore sou gaan onder al die ander, soos straling van sterre agter die swart gat. Dit benodig 'n groot teleskoopskikking om genoeg resolusie te hê om genoeg te versamel en hul rigting akkuraat genoeg op te los. Dit is slegs 'n raaiskoot, maar dit is iets op 'n skaal van miljarde teleskope wat akkuraat oor baie ligjare afstand geposisioneer is.


Kyk agter die gordyn van algemene relatiwiteit

Met behulp van rekenaars en numeriese metodes kan ons die bewegings van planete bereken deur die vergelykings van Newton, Copernicus en ander te gebruik. Verskillende groepe kan verskillende metodes gebruik en almal sal dieselfde resultate kry.

Die probleem met die resultate is dat dit nie presies ooreenstem met wat waargeneem is nie. Hierdie teenstrydighede was 'n bewys dat Newton en die ander iets gemis het.

Einstein, Lorentz en andere het die grondslag gelê vir 'n nuwe teorie. Lorentz-inkrimping en tyddilatasie blyk basiese eienskappe van hierdie nuwe fisika te wees. Die vergelykings wat hierdie effekte beskryf, was ook reguit. Gegewe dieselfde veranderlikes het almal dieselfde resultate behaal en die resultate stem ooreen met wat in die eksperimente waargeneem is.

Dan roep Einstein algemene relatiwiteit op en alles gaan van die spoor af. Newtoniese fisika kan baie akkurate voorspellings maak wat gerekenariseer kan word. Omdat die voorspellings van Newton presies en vry van menslike vooroordeel was, het almal basies dieselfde resultate gekry wat nie heeltemal ooreenstem met wat waargeneem is nie.

Algemene Relatiwiteit kan nie op 'n rekenaar uitgevoer word nie. Dit is nie 'n vergelyking nie. As vier mense probeer om 'n antwoord te lewer (sonder om vooraf die regte antwoord te ken) met GR, kry hulle 4 verskillende antwoorde. GR is meer 'n resep as 'n vergelyking. Die moeilikheidsfaktor en die feit dat baie van die veranderlikes geproduseer word deur die persoon wat die berekening doen, maak van GR 'n intellektuele doolhof.

Newton se vergelykings sal presiese antwoorde lewer. Daardie presiese antwoord kan vergelyk word met wat waargeneem word. Met algemene relatiwiteit is presiese antwoorde nie eens op 'n rekenaar beskikbaar nie (behalwe dinge soos swart gate waar die meeste veranderlikes singulariteite of nulle word).

As daar plaaslike verskynsels is wat GR skend, hoe sou ons dit weet? Algemene Relatiwiteit erken nie die moontlikheid van die Galaktiese snelheidskurwes nie. Maar ons word vertel dat GR plaaslik hou.

As GR nie in staat is om 'n presiese en herhaalbare voorspelling te maak vir almal wat dit gebruik nie, wat help dit dan? Die "fuzziness" van GR maak dit erger as nutteloos, aangesien unieke verskynsels begrawe kan word deur te rapporteer dat dit deur GR verklaar word.

Newton se teorieë het misluk omdat dit presiese voorspellings opgelewer het wat nagegaan kon word. Algemene Relatiwiteit is nie presies nie (soos geformuleer) sodat dit nooit misluk nie. Stel 'n GR-rekenaarprogram op wat almal dieselfde voorspelling gee vir dieselfde veranderlikes, of erken dat GR (ten minste) onvolledig is.

Leemte potensiële energie

Geomartian

Relatiwiteit is net die neem van bekende wetenskaplike waarnemings en die vervaardiging van eenvoudige vergelykings wat die waarnemings beskryf. Dit bevat wel enkele teoretiese analogieë.

Algemene Relatiwiteit is 'n poging om die oorsprong van swaartekrag met behulp van die Einstein-veldvergelykings te verklaar. Einstein se gedagtegang was briljant en het groot intuïsie getoon. Einstein se reikwydte was groter as sy greep. Hy was te vroeg en het kritieke inligting oor die aard van die tyd ontbreek, waarsonder alle oplossings misluk.

E = mc2 kan deur 'n helder 10-jarige bereken word. Die Einstein-veldvergelykings is slegs vir 'n beperkte aantal toestande deur sommige van die helderste gedagtes op hierdie planeet opgelos. Kyk op Wikipedia vir Einstein-veldvergelykings.

E = mc2 definieer ook materie se verhouding met tyd. Dit is 'n uitstekende oorgang na my volgende punt.

Geomartian

Wie gebruik algemene relatiwiteit?

Die Jet Propulsion Lab (JPL) gebruik 'n polinoom van 4 of 5 terme om die voorspellings van planetêre wentelbane reg te stel wat deur die Newtonse fisika geproduseer word. Dit is ontwikkel deur iterasie en krompas nie GR nie.

Ons word meegedeel dat die horlosies en posisies van GPS-satelliete GR gebruik om die snelheids- en gravitasievelkorreksies te genereer. Die Internasionale GNSS-diens (IGS) het 'n eie model wat die regstellingsfaktore vir hierdie satelliete genereer. Dit is ook gebaseer op pragmatisme en wat eintlik werk. Die IGS-regstellings onderdruk ook 'n oortreding van Relatiwiteit. Weereens word GR nie gebruik nie.

Die enigste keer wat ek GR regtig sien gebruik, is wanneer sommige verskynsels GR bedreig.

Kennis is mag. Internasionale GNSS-diens (IGS) onderdruk 'n skending van relatiwiteit wat in die dertigerjare in die olievelde van Texas ontdek is. Baie mense onderskat die tegnologiese vermoëns wat oliegeld beheer. Die oliemaatskappy se gravimeters kon destyds versnellings van 1e-8 meter of beter meet.

Die grootste probleem vir die gebruik van hierdie gravimeters was om die gevolge van getye reg te stel. Hierdie gravimeters is gebruik vir die jag van olie en die opsporing van ertsliggame. Daar was 'n groot finansiële aansporing om 'n model te skep waarmee u hierdie gety-effekte kon regstel. Beleggings in wiskundige modelle soos hierdie het dit eie gemaak, en deur korrupsie het dit Staatsgeheime geword.

Hulle het reggestel vir die Aarde-Maan-gety en hulle reggestel vir die Aarde-Son-gety. Dit is nie maklik nie, aangesien die maan-aarde-voorspellings grens aan chaoties. Hulle het 'n laaste regstelling gehad, maar dit was nie 'n gety-effek nie. Die openbare benaming is 'aarde-gety' wat hoog is om 06:00 en laag omstreeks 18:00. Buitelandse wetenskaplikes wat hierdie verskynsel hanteer, was skepties oor die Amerikaans-Engelse aandrang dat dit 'n atmosferiese verskynsel was, aangesien die instrumente vir atmosferiese effekte vergoed is. Waarom sou die Amerikaners lieg? Die Amerikaners het die rekeninge en hul salarisse betaal, so hulle bly stil.

Hierdie 'aarde-gety' was 'n vreemde dier. In plaas daarvan om sterker op die ewenaar te wees, was dit die sterkste plek waar die aarde met die elliptiese vlak gekruis het. In werklikheid het dit twee pole gehad wat die aarde reghoekig met die son tussen hakies geplaas het. Odder was nog steeds die effek van hierdie gety op horlosies. Namate die rotasie van die aarde klokke nader aan hierdie pole draai, sal hulle vertraag of versnel.

Olie mans is altruïstiese individue wat slegs deur wetenskaplike nuuskierigheid gedryf word, en daarom het hulle hierdie tydelike afwykings geheim gehou.


Kan ons materie deur tyd volg deur na verskillende dieptes in die ruimte te kyk? - Sterrekunde

As ons na ander sterrestelsels kyk, kyk ons ​​in wese terug in die tyd. Kan ons ver genoeg terugkyk om die oerknal self te sien? As dit so is en c konstant is, hoe het ons hier gekom voordat die lig aangekom het?

Dit blyk dat ons die Oerknal om 'n 'tegniese' rede nie kan sien nie. As u daaroor nadink, kan ons lig gebruik om verafgeleë voorwerpe te bekyk omdat lig vrylik voortplant uit die materie wat dit uitstraal. Dit was nie altyd die geval nie: toe die heelal minder as 100 000 jaar oud was, was die materie en die bestraling so dig gepak dat die lig aan die saak "gekoppel" is. Dit beteken dat die lig wat uitgestraal is toe die heelal minder as 100 000 jaar oud was, 'nêrens heen kon gaan nie, en ons dus nie vandag kan bereik nie. Waarnemend beteken dit dat wanneer ons na hoër en hoër rooiverskuiwings probeer kyk, ons 'n "muur" tref wat ooreenstem met die rooi verskuiwing toe die Heelal 100 000 jaar oud was. Hierdie muur is die kosmiese mikrogolf-agtergrond, oftewel CMB. Kyk na hierdie onderwerpblad vir meer inligting vir meer inligting oor die CMB.

Ons kan dus nie terugkyk om die oerknal te sien nie. Aangesien die uitbreiding van die heelal minder is as die snelheid van die lig sedert die uitstoot van die CMB, hoef ons nie bekommerd te wees oor die probleme wat u noem nie.

Hierdie bladsy is laas op 27 Junie 2015 opgedateer.

Oor die skrywer

Kristine Spekkens

Kristine bestudeer die dinamika van sterrestelsels en wat hulle ons kan leer oor donker materie in die heelal. Sy behaal haar doktorsgraad aan Cornell in Augustus 2005, was 'n Jansky-postdoktorale genoot aan die Rutgers Universiteit van 2005-2008, en is nou 'n lid van die fakulteit aan die Royal Military College van Kanada en aan die Queen's University.


Hoe Dark Matter werk

In die opvolgalbum van 1978 vir & quotBorn to Run, & quot, gebruik Bruce Springsteen duisternis aan die rand van die stad as 'n metafoor vir die verlate onbekende wat ons almal in die gesig staar terwyl ons grootword en die wêreld probeer verstaan.

Kosmoloë wat werk om die oorsprong en die lot van die heelal te ontsyfer, moet hulle heeltemal vereenselwig met die gevoel van tragiese verlange van The Boss. Hierdie sterrekyk-wetenskaplikes het hul eie duisternis aan die rand van die stad (of aan die rand van sterrestelsels) in die gesig gestaar terwyl hulle een van die grootste raaisels van die sterrekunde probeer verklaar. Dit staan ​​bekend as donker materie, wat self 'n plekhouer is - soos die x of y wat in die algebra-klas gebruik word - vir iets onbekends en tot dusver ongesiens. Eendag sal dit 'n nuwe naam geniet, maar vandag sit ons vas met die tydelike etiket en sy konnotasies van skaduwee-onsekerheid.

Net omdat wetenskaplikes nie weet wat om donker materie te noem nie, beteken dit nie dat hulle niks daarvan weet nie. Hulle weet byvoorbeeld dat donker materie anders optree as & quotnormale & quot materie, soos sterrestelsels, sterre, planete, asteroïdes en al die lewende en nie-lewende dinge op aarde. Sterrekundiges klassifiseer al hierdie dinge as baroniese saak, en hulle weet dat die belangrikste eenheid die atoom is, wat self bestaan ​​uit nog kleiner subatomiese deeltjies, soos protone, neutrone en elektrone.

Anders as baryoniese materie straal donker materie nie lig of ander vorme van elektromagnetiese energie uit nie, of absorbeer dit ook nie. Sterrekundiges weet dat dit bestaan ​​omdat iets in die heelal belangrike gravitasiekragte uitoefen op dinge wat ons kan sien. Wanneer hulle die gevolge van hierdie swaartekrag meet, skat wetenskaplikes dat donker materie 23% van die heelal uitmaak. Baryoniese aangeleenthede is slegs 4,6 persent. En 'n ander kosmiese raaisel, bekend as donker energie, vorm die res - 'n yslike 72 persent [bron: NASA / WMAP]!

So, wat is donker materie? Waar kom dit vandaan? Waar is dit nou? Hoe bestudeer wetenskaplikes die goed as hulle dit nie kan sien nie? En wat hoop hulle om te wen deur die legkaart op te los? Is donker materie die geheim om die standaardmodel van deeltjiesfisika te verstewig, of sal dit die manier waarop ons die wêreld rondom ons beskou en verstaan, fundamenteel verander? Soveel vrae moet beantwoord word. Ons begin aan die begin - volgende.

Bewyse vir donker saak: die begin

Sterrekundiges is al eeue lank gefassineer deur sterrestelsels. Eerstens kom die besef dat ons sonnestelsel in die arms van 'n massiewe liggaam sterre lê. Toe kom bewyse dat ander sterrestelsels anderkant die Melkweg bestaan. Teen die twintigerjare het wetenskaplikes soos Edwin Hubble duisende universiteite & quotisland gekatalogiseer en inligting oor hul grootte, rotasie en afstand van die aarde opgeteken.

Een belangrike aspek wat sterrekundiges gehoop het om te meet, was die massa van 'n sterrestelsel. Maar jy kan nie net iets weeg wat so groot soos 'n sterrestelsel is nie - jy moet die massa daarvan op ander maniere vind. Een metode is om die ligintensiteit of helderheid te meet. Hoe helderder 'n sterrestelsel is, hoe meer massa besit dit (sien Hoe sterre werk). 'N Ander benadering is om die rotasie van die liggaam of skyf van 'n sterrestelsel te bereken deur op te spoor hoe vinnig sterre in die sterrestelsel om die middel beweeg. Variasies in rotasiesnelheid moet streke van wisselende gewig en dus massa aandui.

Toe sterrekundiges in die 1950's en '60s die rotasies van spiraalstelsels begin meet, het hulle 'n vreemde ontdekking gemaak. Hulle het verwag dat hulle sterre naby 'n sterrestelsel se middelpunt, waar die sigbare materie meer gekonsentreerd is, sou sien, sou vinniger beweeg as sterre aan die rand. Wat hulle eerder gesien het, was dat sterre aan die rand van 'n sterrestelsel dieselfde rotasiesnelheid het as sterre naby die sentrum. Sterrekundiges het dit eers met die Melkweg waargeneem en daarna, in die 1970's, het Vera Rubin die verskynsel bevestig toe sy gedetailleerde kwantitatiewe metings gemaak het van sterre in verskeie ander sterrestelsels, waaronder Andromeda (M31).

Die implikasie van al hierdie resultate het op twee moontlikhede gewys: iets was fundamenteel verkeerd met ons begrip van swaartekrag en rotasie, wat onwaarskynlik gelyk het aangesien die wette van Newton eeue lank baie toetse deurstaan ​​het. Of meer waarskynlik, sterrestelsels en galaktiese trosse moet 'n onsigbare vorm van materie bevat - hallo, donker materie - wat verantwoordelik is vir die waargenome swaartekrag-effekte. Terwyl sterrekundiges hul aandag op donker materie gevestig het, het hulle addisionele bewyse van die bestaan ​​daarvan begin versamel.

Die konsep van donker materie het nie sy oorsprong by Vera Rubin nie. In 1932 merk die Nederlandse sterrekundige Jan Hendrik Oort op dat sterre in ons galaktiese omgewing vinniger beweeg as wat die berekeninge voorspel het. Hy het die term & quotdark matter & quot gebruik om die ongeïdentifiseerde massa te beskryf wat benodig word om hierdie toename in snelheid te veroorsaak. 'N Jaar later het Fritz Zwicky sterrestelsels in die Coma-groep begin bestudeer. Met behulp van helderheidsmetings het hy bepaal hoeveel massa in die groep moes wees en bereken hoe vinnig die sterrestelsels moes beweeg omdat massa en swaartekrag verband hou. Toe hy hul werklike snelhede gemeet het, het hy egter gevind dat die sterrestelsels baie, baie vinniger beweeg as wat hy verwag het. Om die teenstrydigheid te verklaar, het Zwicky voorgestel dat meer massa - twee ordes meer - tussen die sigbare materiaal verborge lê. Soos Oort, noem Zwicky hierdie onsigbare dinge donker materie [bron: SuperCDMS aan Queen's University].

Bewyse vir donker saak: nuwe ontdekkings

Sterrekundiges het voortgegaan om verbasende inligting te vind terwyl hulle die sterre van die heelal bestudeer het. 'N Paar onverskrokke sterrekykers het hul aandag gevestig galaktiese trosse - knope sterrestelsels (so min as 50 en soveel as duisende) wat deur swaartekrag saamgebind is - in die hoop om poele warm gas te vind wat voorheen ongemerk geraak het en wat die massa kan toeskryf aan donker materie.

Toe hulle X-straalteleskope, soos die Chandra X-ray Observatory, na hierdie trosse draai, het hulle inderdaad uitgestrekte wolke met oorverhitte gas gevind. Dit is egter nie genoeg om die verskille in massa te verantwoord nie. Die meting van warm gasdruk in galaktiese trosse het getoon dat daar ongeveer vyf tot ses keer soveel donker materie moet wees as al die sterre en gas wat ons waarneem [bron: Chandra X-ray Observatory]. Anders sou daar nie genoeg swaartekrag in die groep wees om te voorkom dat die warm gas ontsnap nie.

Galaktiese trosse het ander leidrade oor donker materie verskaf. Sterrekundiges het geleer uit die algemene relatiwiteitsteorie van Albert Einstein, en het getoon dat trosse en superklusters die tyd kan verdraai met hul geweldige massa. Ligstrale wat voortspruit uit 'n ver voorwerp agter 'n groep, gaan deur die verwronge ruimtetyd, wat die strale laat buig en saamtrek as hulle na 'n waarnemer beweeg. Daarom dien die groep as 'n groot gravitasielens, net soos 'n optiese lens (sien Hoe werk die lig).

Die verwronge beeld van die verre voorwerp kan op drie moontlike maniere verskyn, afhangende van die vorm van die lens:

  1. Ring - beeld verskyn as 'n gedeeltelike of volledige ligkring wat bekend staan ​​as 'n Einstein-ring. Dit gebeur wanneer die voorwerp, die sterrestelsel met lens en die waarnemer / teleskoop op 'n perfekte manier in lyn is. Dit is soos 'n kosmiese bull's-eye.
  2. Langwerpig of ellipties - beeld word in vier beelde verdeel en verskyn as 'n kruis wat bekend staan ​​as 'n Einstein kruis.
  3. Cluster - beeld verskyn as 'n reeks piesangvormige boë en boë.

Deur die buighoek te meet, kan sterrekundiges die massa van die swaartekraglens bereken (hoe groter die buiging, hoe massiewer die lens). Met behulp van hierdie metode het sterrekundiges bevestig dat galaktiese trosse inderdaad 'n groot massa het wat groter is as die wat gemeet word deur ligstof en het gevolglik addisionele bewyse van donker materie gelewer.

In 2000 het Chandra 'n reusagtige wolk warm gas waargeneem wat die sterrestelsel Abell 2029 omhul, wat gelei het dat sterrekundiges beraam dat die tros 'n hoeveelheid donker materie moet bevat wat gelyk is aan meer as honderd biljoen sonne! As ander trosse soortgelyke eienskappe het, kan 70 tot 90 persent van die massa van die heelal toegeskryf word aan donker materie [bron: Chandra X-ray Observatory].

Terwyl sterrekundiges leidrade versamel oor die bestaan ​​- en ongelooflike hoeveelheid - donker materie, het hulle na die rekenaar gewend om modelle te skep van hoe die vreemde dinge georganiseer kan word. Hulle het opgeleide raaiskote oor hoeveel baryoniese en donker materie in die heelal kan bestaan, en laat die rekenaar dan 'n kaart teken op grond van die inligting. Die simulasies het donker materie getoon as 'n webagtige materiaal wat verweef is met gereelde sigbare materie. Op sommige plekke het die donker materie tot klonte saamgeval. Op ander plekke het dit uitgebrei om lang, draderige filamente te vorm waarop sterrestelsels verstrengel lyk, soos insekte wat in spinnekop vasgevang is. Volgens die rekenaar kan donker materie oral wees, wat die heelal saambind soos 'n soort onsigbare bindweefsel.

Sedertdien het sterrekundiges ywerig gewerk om 'n soortgelyke kaart vir donker materie te skep wat gebaseer is op direkte waarneming. En hulle gebruik een van dieselfde instrumente - gravitasie-lens - wat in die eerste plek die bestaan ​​van donker materie help bewys het. Deur die lig-buigende effekte van sterrestelsels te bestudeer en die data met optiese metings te kombineer, kon hulle die onsigbare materiaal sien en kwoteer en het hulle akkurate kaarte begin saamstel.

In sommige gevalle karteer sterrekundiges enkele trosse. In 2011 gebruik twee spanne byvoorbeeld data van Chandra's X-ray Observatory en ander instrumente soos die Hubble-ruimteteleskoop om die verspreiding van donker materie in 'n sterrestelselgroep bekend as Abell 383, wat ongeveer 2,3 miljard ligjare geleë is, in kaart te bring. van die aarde af. Albei spanne het tot dieselfde gevolgtrekking gekom: die donker materie in die groep is nie bolvormig nie, maar eiervormig, soos 'n Amerikaanse voetbal, gerig met die een kant na die waarnemers. Die navorsers was dit egter nie eens oor die digtheid van die donker materie in Abell 383 nie. Die een span het bereken dat die donker materie na die middel van die groep toegeneem het, terwyl die ander minder donker materie in die middel gemeet het. Selfs met hierdie teenstrydighede het die onafhanklike pogings bewys dat donker materie opgespoor en suksesvol gekarteer kon word.

In Januarie 2012 het 'n internasionale span navorsers resultate van 'n selfs meer ambisieuse projek gepubliseer. Met behulp van die 340-megapixel-kamera op die Kanada-Frankryk-Hawaii-teleskoop (CFHT) op die Mauna Kea-berg in Hawaii, het wetenskaplikes die swaartekrag-lenseffekte van 10 miljoen sterrestelsels in vier verskillende gebiede aan die hemel oor 'n tydperk van vyf jaar bestudeer. Toe hulle alles aanmekaarwerk, het hulle 'n prentjie van donker materie wat oor 1 miljard ligjare se ruimte kyk - die grootste kaart van die onsigbare goed wat tot dusver geproduseer is. Hul finale produk lyk soos die vorige rekenaarsimulasies en het 'n groot web van donker materie wat oor die ruimte gestrek het, geopenbaar en gemeng met die normale materie wat ons al eeue ken.

Identifisering van deeltjies van donker materiaal

Op grond van die bewyse is die meeste sterrekundiges dit eens dat daar donker materie is. Daarbenewens het hulle meer vrae as antwoorde. Die grootste vraag, durf ons sê een van die grootste in die hele kosmologie, fokus op die presiese aard van donker materie. Is dit 'n eksotiese, onontdekte soort materie, of is dit 'n gewone saak wat ons moeilik kan waarneem?

Laasgenoemde moontlikheid lyk onwaarskynlik, maar sterrekundiges het 'n paar kandidate oorweeg, waarna hulle verwys MACHO's, of massiewe kompakte stralevoorwerpe. MACHO's is groot voorwerpe wat in die stralekrans van sterrestelsels voorkom, maar dit kan nie opgemerk word nie, omdat hulle so 'n lae helderheid het. Sulke voorwerpe sluit in bruin dwerge, uiters dowwe wit dwerge, neutronsterre en selfs swart gate. MACHO's dra waarskynlik 'n bietjie by tot die raaisel oor die donker materie, maar daar is eenvoudig nie genoeg om al die donker materie in 'n enkele sterrestelsel of sterrestelsel te verreken nie.

Sterrekundiges dink dat dit waarskynliker is dat donker materie bestaan ​​uit 'n heeltemal nuwe soort materie wat uit 'n nuwe soort elementêre deeltjie gebou is. Aanvanklik het hulle dit oorweeg neutrino's, fundamentele deeltjies wat eers in die dertigerjare gepostuleer is en toe in die vyftigerjare ontdek is, maar omdat dit so min massa het, is wetenskaplikes in twyfel of dit baie donker materie uitmaak. Ander kandidate is gedagtes van wetenskaplike verbeelding. Hulle staan ​​bekend as WIMP's (vir massiewe deeltjies met swak interaksie), en indien dit bestaan, het hierdie deeltjies massas wat tien of honderde kere groter is as die van 'n proton, maar is dit so swak met gewone materie dat dit moeilik is om op te spoor. WIMP's kan enige aantal vreemde deeltjies insluit, soos:

  • Neutralino's (massiewe neutrino's) - Hipotetiese deeltjies wat soortgelyk is aan neutrino's, maar swaarder en stadiger. Alhoewel hulle nie ontdek is nie, is hulle 'n voorloper in die WIMP's-kategorie.
  • Aksies - Klein, neutrale deeltjies met 'n massa van minder as 'n miljoenste elektron. Aksies is moontlik tydens die oerknal oorvloedig geproduseer.
  • Fototone - Soortgelyk aan fotone, elk met 'n massa van 10 tot 100 keer groter as 'n proton. Fototino's is nie gelaai nie en is, getrou aan die WIMP moniker, swak met materie.

Wetenskaplikes regoor die wêreld hou aan om aggressief na hierdie deeltjies te jag. Een van hul belangrikste laboratoriums, die Large Hadron Collider (LHC), lê diep onder die grond in 'n 16,5 myl lang sirkelvormige tonnel wat die grens tussen Frankryk en Switserland oorsteek. Binne die tonnel versnel elektriese velde twee proton-verpakte balke tot absurde snelhede en laat dit dan bots, wat 'n komplekse bespuiting van deeltjies bevry. Die doel van LHC-eksperimente is nie om WIMP's direk te vervaardig nie, maar om ander deeltjies te produseer wat in donker materie kan verval. Hierdie vervalproses, hoewel dit amper oombliklik is, sal wetenskaplikes in staat stel om veranderinge in die momentum en energie op te spoor wat indirekte bewyse van 'n splinternuwe deeltjie sal lewer.

Ander eksperimente behels ondergrondse detektors wat hoop om deeltjies van donker materie wat deur en deur die aarde rits, te registreer (sien sybalk).

As sterrestelsels in die verte gewoonlik in 'n kleed van donker materie lê, kan die Melkweg ook. En as dit so is, dan moet die aarde deur 'n see van donker materie-deeltjies gaan terwyl dit om die son wentel en die son deur die sterrestelsel beweeg. Om hierdie deeltjies op te spoor, het die Cryogenic Dark Matter Search (CDMS) -span 'n reeks germaniumselle diep onder die grond in Soudan, Minn, begrawe. As daar deeltjies van donker materie bestaan, moet dit deur vaste aarde gaan en die kerne van die germaniumatome tref, wat sal terugval en klein hoeveelhede hitte en energie sal produseer. In 2010 het die span berig dat hy twee kandidaat-WIMP's ontdek het wat die verskeidenheid selle tref. Uiteindelik het die wetenskaplikes besluit dat die resultate nie statisties betekenisvol was nie, maar dit was nog 'n tergende leidraad in die soeke na die geheimsinnigste stof in die heelal.

Alternatiewe vir Dark Matter

Nie almal word aan donker materiaal verkoop nie, nie deur 'n lang skoot nie. 'N Paar sterrekundiges glo dat die wette van beweging en swaartekrag, geformuleer deur Newton en uitgebrei deur Einstein, moontlik uiteindelik hul ooreenstemming kon bereik. As dit die geval is, kan 'n verandering van swaartekrag, en nie een of ander ongesiene deeltjie nie, die effekte wat aan donker materie toegeskryf word, verklaar.

In die 1980's het die fisikus Mordehai Milgrom voorgestel dat die tweede bewegingswet van Newton (krag = massa x versnelling, f = ma) in die geval van galaktiese bewegings weer ondersoek moes word. Sy basiese idee was dat die tweede wet teen baie lae versnellings, wat ooreenstem met groot afstande, onklaar geraak het. Om dit beter te laat werk, het hy 'n nuwe wiskundige konstante in die beroemde wet van Newton gevoeg, wat die wysiging noem MAAND, of Gemodifiseerde Newtoniaanse dinamika. Omdat Milgrom MOND ontwikkel het as 'n oplossing vir 'n spesifieke probleem, nie as 'n fundamentele fisika-beginsel nie, het baie sterrekundiges en fisici vuil gehuil.

MOND kan ook nie rekenskap gee van bewyse van donker materie wat ontdek is deur ander tegnieke wat nie die tweede wet van Newton insluit nie, soos röntgenstronomie en swaartekraglense. 'N 2004-hersiening van MOND, bekend as TeVeS (Tensor-Vector-skalaar swaartekrag), stel drie verskillende velde in ruimtetyd bekend om die een gravitasieveld te vervang. Omdat TeVeS relatiwiteit insluit, kan dit verskynsels soos lenswerk akkommodeer. Maar dit het die debat nie opgelos nie. In 2007 het fisici die tweede wet van Newton getoets tot versnellings van so min as 5 x 10 -14 m / s 2 en gerapporteer dat f = ma geld sonder die nodige wysigings (sien die Amerikaanse Instituut vir Fisika Nuusupdate: & quotNewton se Tweede Bewegingswet, & quot 11 April 2007), wat MOND nog minder aantreklik laat lyk.

Nog ander alternatiewe beskou donker materie as 'n illusie as gevolg van kwantumfisika. In 2011 het Dragan Hajdukovic van die Europese Organisasie vir Kernnavorsing (CERN) voorgestel dat die leë ruimte gevul is met deeltjies van materie en antimaterie wat nie net elektriese teenoorgesteldes is nie, maar ook swaartekragte. Met verskillende gravitasieladings vorm die materie en antimaterie deeltjies gravitasie dipole in die ruimte. As hierdie dipole naby 'n sterrestelsel gevorm het - 'n voorwerp met 'n massiewe swaartekragveld - sou die gravitasie-dipole gepolariseer word en die swaartekragveld van die sterrestelsel versterk. Dit sou die swaartekrag-effekte van donker materie verklaar sonder om nuwe of eksotiese vorms van materie te benodig.


Wat vandag bestaan ​​of sal daar in die nabye toekoms gebeur

Impulsrylaan: Die impulsaandrywing is nie anders as ons chemiese vuurpyle van vandag nie, maar net meer gevorderd. Aangesien vooruitgang vandag plaasvind, is dit nie onredelik om te dink dat ons eendag aandrywingstelsels sal hê wat soortgelyk is aan die impuls wat op die ruimteskip aangedryf word nie. Onderneming.

Mantelapparate: Die ironie hier is natuurlik dat dit 'n tegnologie is wat mense nog nie vroeg sou moet begryp nie Star Trek reeks (hoewel die Klingon-ryk dit het). Tog is dit een van die tegnologieë wat die naaste daaraan bestaan ​​om vandag 'n werklikheid te word. Daar is toestelle wat klein voorwerpe omhul tot die grootte van mense, maar om 'n hele ruimteskip te laat verdwyn, is nog steeds 'n hele entjie weg.

Kommunikasie-toestelle: In Star Trek gaan niemand êrens sonder een nie. Alle lede van Starfleet het 'n toestel saamgeneem waarmee hulle met ander bemanningslede kon kommunikeer. In werklikheid gaan baie mense nêrens sonder hul slimfone nie, en daar is selfs werkende kentekens.

Tricorder-agtige toestelle: In Star Trek word draagbare sensors “in die veld” gebruik vir alles van mediese diagnoses tot steen- en atmosferiese monsterneming. Vandag se ruimtetuie op Mars en verder gebruik sulke sensors, hoewel dit nog nie heeltemal "draagbaar" is nie. In onlangse jare het spanne uitvinders werkende mediese tricorder-agtige masjiene geskep wat reeds besig is om in die mark te kom.


7 Tydelikheid


Tydelikheid is nog 'n filosofiese begrip wat betrekking het op tyd. Tydelikheid is die filosofiese studie van die verlede, hede en toekoms, en wat dit vir ons beteken, die bewuste agente wat ons lewens leef. As tyd 'n studie is van 'n lineêre pad langs 'n as, of 'n sirkelbeweging waardeur alle dinge herhaal, en die regte tydsduur die ervaring is van tyd soos ons dit van binne leef, dan is tydelikheid die fokus op hoe dinge verander. Tydelikheid is die werklike gevolge van tyd, want 'n piesang gaan van 'n toestand van onryp, tot ryp, tot vrot, of hoe 'n liggaam stadig ontbind oor 'n reeks dae, weke, maande en jare. Terwyl die dae, weke, maande en jare die metings van tyd is, vind die konkrete proses van ontbinding plaas deur tydelikheid.

Since the time of Augustine, philosophers have sought to tease out the difference between time and temporality by noting that time, unlike temporality, could only be measured outside of the framework of eternity, while temporality was the process of going toward eternity, and as a pure process, rather than measurement, time was an intrinsic part of the making (or unfolding) of eternity. [4] As each moment flows seamlessly into the next, the human existence cannot take place without this constant transition into the future. Unlike linear time, which is an abstraction between two moments and which inherently means the measurement of time must stop, temporality is constant, ongoing, and forever in flux and must take place in reference to other changing things.


Can we track matter through time by looking at different depths in space? - Sterrekunde

Structure of the Universe

Does the Universe have an edge, beyond which there is nothing?
Galaxies extend as far as we can detect. with no sign of diminishing.There is no evidence that the universe has an edge. The part of the universe we can observe from Earth is filled more or less uniformly with galaxies extending in every direction as far as we can see - more than 10 billion light-years, or about 6 billion trillion miles. We know that the galaxies must extend much further than we can see, but we do not know whether the universe is infinite or not. When astronomers sometimes refer (carelessly!) to galaxies "near the edge of the universe," they are referring only to the edge of the OBSERVABLE universe - i.e., the part we can see.
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Are the galaxies arranged on the surface of a sphere?
No. Galaxies are not actually arranged on the surface of a sphere. Many students and teachers mistakenly believe that the galaxies in the universe are arranged on the surface of a sphere. One origin of this misconception is the common demonstration of blowing up a balloon to model the expansion of the universe. Another is the (mistaken) belief that during the Big Bang, matter expanded into space from a point (see below). A third is the finding that many clusters of galaxies appear to be arranged around the outside of "bubble-like" voids in the universe. But on the largest scales that astronomers have observed, each chunk of space appears to have just as much matter as any other equivalent chunk.
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Why can't we see the whole universe?
We can see just about as far as nature allows us to see. Two things prevent us from seeing further. First, the universe has been evolving with time. Stars and galaxies did not always exist. Therefore light from MOST of the galaxies in the universe has not yet had time to reach us. Second, the universe has been expanding with time. Again, light from MOST of the universe has not yet had time to reach us.

If you could suddenly freeze time everywhere in the universe, and magically survey all of creation, you would find galaxies extending out far beyond what we can see today. But how far, no one knows.
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Does the term "universe" refer to space, or to the matter in it, or to both?
Just a hundred years ago, scientists thought of the universe in terms of matter. Space was just the "emptiness" in which matter lived.

Today, the situation is reversed. During the twentieth century, scientists learned that space is not "nothingness." First, Einstein showed that space has structure: It is flexible and can be stretched. (In fact, when astronomers talk about the "expansion of the universe," they are referring to the stretching of space between clusters of galaxies - NOT to the motion of galaxies through space.) Later, scientists found other properties of space. For example, matter and anti-matter are routinely created in the laboratory from space itself (and an energy source) the kinds of particles that can exist reflect the structure of space. In fact, there is now evidence that space itself MAY possess some slight amount of energy of its own, of a form previously unknown. If so, space may actually have weight!

Discovering the properties of space remains one of the deepest and most important problems in modern science.
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Evolution of the Universe

Did the Universe expand from a point? If so, doesn't the universe have to have an edge?
No. The Big Bang was not an explosion IN space. It was a process that involved ALL of space. This misconception causes more confusion than any other in cosmology. Unfortunately, many students, teachers, and scientists(!) mistakenly picture the "Big Bang" as an explosion that took place at some location in space, hurtling matter outward.

In reality, ALL of space was filled with energy right from the beginning. There was no center to the expansion, and no magical point from which matter hurtled outward. The confusion arises in part because of the amazing conclusion that the OBSERVABLE portion of the universe was once packed into an incredibly tiny volume. But that primordial pellet of matter and energy was NOT surrounded by empty space. it was surrounded by more matter and energy (which today is beyond the region we can observe.) In fact, if the whole universe is infinitely large now, then it was always infinite, including during the Big Bang as well.

To put it another way, the current evidence indicates only that the early universe - the WHOLE universe - was extremely DENSE - but not necessarily extremely small. Thus the Big Bang took place everywhere in space, not at a particular point in space.
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Then where did the idea that the universe was once a point come from?
For much of the twentieth century, astronomers and physicists believed that space might NOT be infinitely large - that is, space might actually curve around on itself to form a "closed universe." This unusual three-dimensional shape was discovered in the mid-1800's by the great mathematician Bernhard Riemann. The shape was later favored by Einstein as a possible shape for the universe. Such a closed universe would have a finite volume, yet no boundaries or edges. Although closed universes cannot be visualized from the outside, they CAN be visualized from the inside. For example, the image at right gives an idea of what a tiny closed universe might look like. (In a real closed universe, you cannot see the back of your head, the way you can here.) If you shrink such a space down, then everything in it gets closer together, and the volume of the closed universe gets closer and closer to zero. But there is still nowhere OUTSIDE the space for an observer.

Current evidence shows that our part of the universe appears not to be curved. This tells us that either the universe is infinitely large, or else is so large that we cannot detect its curvature from the tiny portion we can observe -- just as we could not tell that the Earth was curved if our measurements were confined to a sandbox!
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If the universe started out so dense, why didn't it collapse into a black hole?
A large enough clump of matter will collapse to form a black hole, but ONLY if it is surrounded by (relatively) empty space. During the Big Bang, there WAS NO empty space: ALL of space was filled more or less uniformly with matter and energy there was no "center of attraction" around which matter could coalesce. Under these circumstances, a cosmic-scale black hole will not form (and lucky for us!).
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Why does looking out in space mean looking back in time?
Because it takes time for light from distant objects to reach us. We see the sun as it looked about 8 minutes ago. other stars as they looked years ago. and distant galaxies as they looked millions or even billions of years ago.
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I've heard the expansion of the universe may be speeding up. Is there an "anti-gravity" force?
Current studies of distant exploding stars have led astronomers to conclude that the universe is not only expanding - the expansion may be accelerating with time. This is not due to an "anti-gravity force" but rather to gravity itself. In fact, the effect was predicted as a possibility on the basis of Einstein's theory of gravity.

(It may seem strange that gravity can be "repulsive" as well as attractive. The secret is that the expansion applies to the fabric of space itself - not to the matter within it space behaves very differently from matter. For example, no chunk of matter can travel through space at the speed of light. Yet SPACE itself can expand faster than the speed of light. Similarly, while matter is attracted to other matter by gravity, space behaves differently: Space can either expand or contract as a consequence of gravity.)
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When they say "the universe is expanding," what exactly is expanding?
As bizarre as it may seem, space itself is expanding - specifically, the vast regions of space between galaxies.
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But if you can't see space, or feel it or touch it - how can it be expanding ?
According to Einstein, space is not simply emptiness it's a real, stretchable, flexible thing. In fact, understanding the properties and behavior of space is a major goal of modern physics.
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Why did anyone ever think that space should be expanding? Isn't it a far-fetched idea?
The notion that space is expanding is a prediction of Einstein's theory of gravity, which describes a simple but universal relationship between space, time, and matter. But it was a prediction that Einstein didn't believe in fact, he tried to modify his theory to get rid of it.
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Then how do we know that space really is expanding?
In the late 1920's, the astronomer Edwin Hubble first observed that distant galaxies are moving away from us, just as would be expected if the space between galaxies were growing in volume - and just as predicted by Einstein's theory of gravity. Since then, astronomers have measured this recession for millions of galaxies. But there's other evidence as well.
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Are the galaxies in the universe moving through space?
No, the galaxies sit more or less passively in the space around them. As the space between galaxies expands, it carries the galaxies further apart - like raisins in an expanding dough.
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But I heard that our Milky Way galaxy may one day collide with a neighboring galaxy. If galaxies are all moving apart from each other, how can they collide?
The universe is a chaotic place - and the gravity from one galaxy, or from a group of galaxies, may disturb the motion of its near neighbors, causing them to collide. However, on average, when you compare two large enough chunks of space, the galaxies in one are moving away from the galaxies in the other.
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Where did the Big Bang scenario come from?
If space (and everything with it) is expanding now, then the universe must have been much denser in the past. That is, all the matter and energy (such as light) that we observe in the universe would have been compressed into a much smaller space in the past. Einstein's theory of gravity enables us to run the "movie" of the universe backwards - i.e., to calculate the density that the universe must have had in the past. The result: any chunk of the universe we can observe - no matter how large - must have expanded from an infinitesimally small volume of space.
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How do we know when the Big Bang took place?
By determining how fast the universe is expanding now, and then "running the movie of the universe" backwards in time, using Einstein's theory of gravity. The result is that space started expanding about 15 billion years ago, give or take a few billion years. This number is uncertain, in part because of uncertainties in our current measurements of how fast the universe is expanding, how much matter and energy there is, and even what kind of energy there is in the universe.
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Do we know where, in space, the Big Bang took place?
It's a common misconception that the Big Bang was an "explosion" that took place somewhere in space. But the Big Bang was an expansion of space itself. Every part of space participated in it. For example, the part of space occupied by the Earth, the Sun, and our Milky Way galaxy was once, during the Big Bang, incredibly hot and dense. The same holds true of every other part of the universe we can see.

Artists may find it more dramatic to draw a "fireball" expanding into space, but as far as we know, there would have been no such "ball."
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How do we know there really was a Big Bang?
As mentioned above, we observe that galaxies are rushing apart in just the way predicted by the Big Bang scenario. But there are other important clues.

Astronomers have detected, throughout the universe, two chemical elements that could only have been created during the Big Bang: hydrogen and helium. Furthermore, these elements are observed in just the proportions (roughly 75% hydrogen, 25% helium) predicted to have been produced during the Big Bang. This prediction is based on our well-established understanding of nuclear reactions - independent of Einstein's theory of gravity.

Second, we can actually detect the light left over from the era of the Big Bang. The blinding light that was present in our region of space has long since traveled off to the far reaches of the universe. But light from distant parts of the universe is just now arriving here at Earth, billions of years after the Big Bang. This light is observed to have all the characteristics expected from the Big Bang scenario and from our understanding of heat and light.
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But I've heard on the news there are problems with the Big Bang theory. Is it still just a "theory"?
The Big Bang is actually not a "theory" at all, but rather a scenario about the early moments of our universe, for which the evidence is overwhelming. But the Big Bang scenario cannot be the whole story, and its details are a subject of intense research.
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Was the Big Bang the origin of the universe?
It is a common misconception that the Big Bang was the origin of the universe. In reality, the Big Bang scenario is completely silent about how the universe came into existence in the first place. In fact, the closer we look to time "zero," the less certain we are about what actually happened, because our current description of physical laws do not yet apply to such extremes of nature.

The Big Bang scenario simply assumes that space, time, and energy already existed. But it tells us nothing about where they came from - or why the universe was born hot and dense to begin with.
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Are there theories that go beyond the Big Bang?
Yes, there are theories that build on the Big Bang scenario by adding insights from physics about the structure of space itself. Watch this space for more details.
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Ask an astronomer: What was Einstein’s most mind-blowing discovery?

Do space and time really exist? NASA astronomer Michelle Thaller looks at the implications of Einstein's famous equation E=mc2.

Dr. Michelle Thaller is an astronomer who studies binary stars and the life cycles of stars. She is Assistant Director of Science Communication at NASA. She went to college at Harvard University, completed a post-doctoral research fellowship at the California Institute of Technology (Caltech) in Pasadena, Calif. then started working for the Jet Propulsion Laboratory's (JPL) Spitzer Space Telescope. After a hugely successful mission, she moved on to NASA's Goddard Space Flight Center (GSFC), in the Washington D.C. area. In her off-hours often puts on about 30lbs of Elizabethan garb and performs intricate Renaissance dances. For more information, visit NASA.

MICHELLE THALLER: If you were to convert my hand into pure energy using Einstein's equation you could have nuclear Armageddon on a global scale. There is so much mass in here that if you were to convert me into pure energy I could blow up the planet.

There are very few people in the world where I just simply say their name and you immediately can picture them, probably many different images of them, and one of them certainly is Einstein. I just say that word and all of a sudden you're thinking about crazy white hair and the mustache, somebody who is brilliant, you know, those wonderful unknowing eyes with lots of smile lines around them. Everybody knows who Einstein is and people understand that he was a very famous scientist, but I think that people often don't grasp the true depth and the profound nature of the things that Einstein introduced to us.

I also spend a lot of time debunking, in some ways, the myth of Albert Einstein. A lot of people seem to think that he was somebody that worked outside of traditional academics, he wasn't part of the academic establishment, he came up with all this brilliant stuff all by himself. Well, that wasn't true either. Einstein was a professor, he actually taught a lot at the University of Bern and also in Berlin and then eventually came to Princeton. He was very much a product of the time and the science that was going on. There were brilliant people at this time. Science was changing in so many different ways and for a lot of things Einstein found himself kind of in the right place at the right time to see two different things going on and say ah-ha, those things actually go together. And to me that really was some of the real brilliance of Einstein, was that he became a bridge between many, many different subject matters.

It amazes me that he was one of the people when he was doing his doctoral dissertation, who figured out the size and speed of molecules in the air all around you. People didn't realize at the time, when Einstein was a younger student in college, that air was made of molecules, little things that are constantly bouncing off each other and bouncing off of you and that's what we think of as air. And it became known that there was a tremendous number of these. To give you an idea, in about a square foot of air, if I had about a square foot of air of volume in front of me, how many molecules are in a square foot of air? The answer is approximately 10 to the 23, which means a one with 23 zeros after that. That's such a big number we don't have a name for it. And all of those molecules are bouncing off you at hundreds of miles an hour. Can you imagine when they realized that's what air really was? Einstein was a major figure in that and then there was so many other things he did.

But I think if I were to ask you, what is Einstein really known for? The thing that would pop into your head, even if you don't know what it means, is the equation E=mc2. So, this is something that I have to say takes my breath away in the implications of this. It is absolutely incredible. What it means is that energy, pure energy, is really the same thing as matter, as mass. When we talk about matter—I'm made of matter, I'm made of atoms and molecules, I'm a solid thing—what you're really talking about in many ways is the fact that I have mass. I have something that you can measure the gravity of. I'm a solid, substantive thing. And you think about energy—so maybe an example of pure energy could be a beam of light. A beam of light has no mass at all, there's no substance to it, it doesn't have a volume, it's just pure energy. E=mc2 is the bridge, and this is what Einstein was so brilliant at, bridging two very different parts of the universe all at once: the world of matter and the world of pure energy. 'C' in this equation represents the speed of light and the speed of light is a huge number. To give it to you just in some units you might be able to understand, the speed of light is 186,000 miles per second. So, that's how fast light travels through space, through empty space it would go about 186,000 miles every second. And that's a big number already and to square something means you multiply it by itself, so two times two equals four—you're squaring two. Four times four equals 16, you square that. Now think about squaring 186,000 and that's in the units of miles per second. That's a big number.

And so, think about the equation: M means mass, the amount of gravitational oomph we have, and E is energy. What that means literally is that what you are is some super intense almost kind of coagulated form of energy. If you were to convert just a little bit of my mass into pure energy you would have a tremendous amount of energy. And let me give you an example of how much that's true. The thing that in our experience can actually convert mass into energy is a nuclear bomb. A nuclear bomb these days we have very powerful ones called hydrogen bombs. In the case of the bomb that were first used on the city of Hiroshima in Japan, the amount of matter that was converted into pure energy, that killed 100,000 people and leveled a city, that was the equivalent to about a third of the mass of a dime. So, think about a dime coin, cut it in three that's about how much mass blew up the entire city of Hiroshima. So, you can think about the fact that in my hand, if you were to convert my hand into pure energy using Einstein's equation, you could have nuclear Armageddon on a global scale. There is so much mass in here that if you were to convert me into pure energy I could blow up the planet. That's an amazing thing to think of, is that what you are is this somehow changed modified form of energy.

And by the way, you can go the other way too—you can actually turn energy into mass. And this is what we do in the particle accelerators all around the earth. I had the wonderful opportunity, and this was like being a kid in a candy store, I've actually gone to tour CERN, which is the largest particle collider in the world. It's in Switzerland and France. And CERN actually has this, I believe the circumference of the circle is about 26 kilometers—it is in Europe, you use kilometers—and it slams tiny particles together at very, very close to the speed of light. And in some cases they slam those particles into bigger, heavier atoms like gold nuclei or lead nuclei, but for a tiny amount of time, less than a trillionth of a second, they actually create conditions very, very close to what it was like a little bit after the Big Bang when the temperature of the universe was measured in trillions of degrees. And that is so much energy that it creates particles, it creates mass just from the pure energy of that collision. And that's how we discover new particles. Have you ever wondered why does the particle collider discover new particles? You get to bigger and bigger energies, you collide things faster and harder together and the more energy you can build up the more massive a thing you can make. So, you can find more massive particles the higher energy you juice this collider up to. And now, of course, we want to actually design the next generation of colliders some of the things we're hoping to find are maybe things like a particle of dark matter. We now know the universe is made of this mysterious substance called dark matter but we have no idea what particle is associated with it. It may be that that particle is massive enough we haven't been able to build it yet.

One of the incredible things about these particle accelerators is that they use Einstein's equation backwards, they turn energy into mass. And once you get to a high enough energy, the universe can make anything it wants that has that amount of energy in its mass. So, that's the way we have found more and more exotic particles, the Higgs boson, different sorts of quarks and building blocks of atoms, all by getting to these higher and higher energies.

Okay, but here's the thing that really sort of keeps me up at night about the equation. Pure energy, like a photon, is very, very different from you and I. And one of the ways that it's very different is that it travels at the speed of light. A photon does not exist standing still, ever, in any part of the universe. A photon is always traveling at the speed of light that's sort of the definition of its existence. And one of the amazing laws that Einstein found was that when you travel close to the speed of light, as you approach that speed time, according to your measurements of it, your sense of time slows down more and more. If you're going half the speed of light your time slows down quite noticeably. If you're going at the speed of light, time ceases to exist. To a photon, to the light, the light that's bouncing off my face right now, the reason you can see me is the light interacting with me and coming to your eyes, that light does not experience time and it did not experience the distance between the camera and my face. To a beam of light, the universe is a single point of space and time. It's almost as if to a beam of light the universe never expanded. All points of space and time collapse into one thing—and yet here we are as matter interacting with light we have time, we have space, we are moving through time and space. I am made of pure energy and in a way I'm made of things that don't experience space and time in a very basic sense. And then something happens and all of a sudden there is gravity, there is time, there is matter, there is mass.

What actually is that transition? What makes something massless, timeless, no idea that there's a separation in space between objects? That blows my mind. How am I simultaneously energy and matter at the same time? And I think that once we really understand this we're going to be in for some very difficult truths to accept. It may be that there is no space or time as we know it, really. Everything that we know of as space and time is some kind of a projection, some kind of a way of viewing this single thing, this singularity that is the universe. If that's true, all points of space and time exist at once. What about my past and my future are all there, according to a beam of light. If we really understand this we may actually be sort of knocking at the door of what reality is and right now I have to say we have no idea what the nature of reality itself is. Maybe this will help us get a clue.


Track Elon Musk’s Tesla Roadster in space with this aptly named website

Last week, SpaceX CEO Elon Musk launched his now-famous red Tesla Roadster into space, atop the first Falcon Heavy rocket. Cameras mounted on the car live-streamed the Starman’s journey for a few hours, giving us some unforgettable shots of Earth before going black. But if you want to know where the first car cruising our Solar System is right now, there’s a website for that — aptly called Whereisroadster.com.

The website was created by engineer Ben Pearson, who’s been passionate about space since he was in third grade. “I read every book in my little library that I could about space and space exploration stuff,” he tells The Verge. The day of the Falcon Heavy launch, he saw that people online were asking questions about tracking the Tesla Roadster in space. So he decided to figure it out — and create a website that gives the answer.

An animation tracking the orbit of Musk’s Tesla Roadster over a few days. Animation: Whereisroadster.com

If you really want to know, the Roadster is now over 1.8 million miles (over 3 million kilometers) from Earth, according to Pearson’s website, which uses data from NASA’s Jet Propulsion Laboratory. At first, the car was supposed to go out to the orbit of Mars. But it actually overshot that trajectory, going slightly beyond the Red Planet’s path but not as far out as the asteroid belt, as Musk originally claimed.

After the launch, Pearson started modeling where the car could be in space, but his calculations didn’t match the orbit Musk had released. How did he feel when he found out he was right and Elon Musk was wrong? “I was just relieved to know that I wasn’t doing anything critically wrong,” Pearson says. “Elon Musk is a visionary man, incredibly far forward, but there’s a reality distortion field when it comes to him.”

Still, he’s a fan: “I like that he’s willing to take risks and do cool stuff that people just keep saying it’s not possible and he figures out a way to make it possible.”

Eventually, NASA released accurate information of where the Roadster is in the sky, so Pearson figured out a way to store the NASA data on his website to visualize where the car is in real time. Now you can track the Tesla’s orbit around the Sun, alongside the orbits of Mercury, Venus, Earth, Mars, and the dwarf planet Ceres, on a map of our Solar System. You can also follow the car’s path around the Sun from today to almost the end of 2020, and check when the Roadster will be getting particularly close to Mars or the Earth.

One of the close passes to our planet will occur in 2091, Pearson says. And that would be a good time for “space enthusiasts” to go retrieve the Roadster, so that it can end up in a museum. At least that’s what Pearson believes will happen to the car in the long run. More likely, the Roadster is just going to keep floating around space — and maybe crash into the Earth, Venus, or the Sun within 10 million years.


Time, Space, and Matter

There is an immeasurably and unimaginably huge universe out there (even though the most important part of it appears to be here). The physical universe is "temporal"&mdashits physical characteristics are defined qualitatively and quantitatively in and by time, space, and mass/energy (usually abbreviated as just "matter").

Any effort to determine the cause of the universe is purely hypothetical. No human was there to observe the processes, so any attempt to understand events of pre-history (especially original events) must, therefore, be based on "belief systems," or presuppositions. While the theories and ideas may be many, the presuppositions can only be of two sorts: 1) there is an infinite series of causes, going back into infinite time, with no ultimate Cause or 2) there exists an uncaused First Cause that was "outside" or transcendent to the universe.

Many scientists today conduct their research based on their presupposition or belief that nothing exists beyond the natural world&mdashthat which can be seen around us&mdashand thus they do not accept that any ultimate Cause exists.

Scientists at ICR hold to the presupposition that the "uncaused First Cause" is the Creator who exists outside of the physical creation He made. Time is not eternal, but created. To ask what happened in time before time was created is to create a false paradox without meaning. There was no "before" prior to the creation of the triune universe of time, space, and mass/energy.

Yet even more amazing (and the universe is amazing) is the historic fact that the Creator-God, after purposefully creating the time-space-matter universe, chose to enter it in the God-human person of Jesus Christ&mdashfor the sole purpose of providing a means by which humanity could have a personal relationship with the Creator.

"And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth&rdquo (John 1:14).


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