html,body{font-size:16px !important;line-height:18px !important;height:100%;color:#333;padding:0;margin:0}*,html,body{font-family:"Poppins",sans-serif;font-weight:normal;letter-spacing:normal;-webkit-font-smoothing:antialiased;-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box;text-rendering:geometrirecision;-webkit-tap-highlight-color:rgba(0,0,0,0);outline:none !important;letter-spacing:-0.1px;word-wrap:break-word}.row{display:flex;flex-wrap:wrap;margin-left:-10px;margin-right:-10px;padding:0 2px}.col{flex:0 0 auto;width:25%;margin-bottom:20px;padding-left:10px;padding-right:10px}.col .entity-item{height:100%}strong,b{font-family:"Poppins",sans-serif;font-weight:bold}figure{margin:0;padding:0}a{text-decoration:none;color:#174fae}a:hover{text-decoration:underline}pre{padding:5px;margin-top:20px;background:#f3f3f3;border:1px solid #ccc}p{font-size:18px;line-height:24px}.link{cursor:pointer}.nowrap{white-space:nowrap}.overflow-auto{overflow:auto !important;-webkit-overflow-scrolling:touch !important}.h1,.h2,.h3,.h4,.h5,.h6,h1,h2,h3,h4,h5,h6{font-family:"Poppins",sans-serif;font-weight:bold}.multiple:after{content:',';margin-right:4px}.multiple:last-child:after{content:'';margin-right:0}.icon-home{display:flex;justify-content:center;align-items:center}.icon-home svg{fill:#fff;width:15px;height:15px}.icon svg{fill:#fff;width:35px;height:35px}.m-0{margin:0 !important}.p-0{padding:0 !important}.mt-0{margin-top:0 !important}.mb-0{margin-bottom:0 !important}.mb-2{margin-bottom:10px !important}.me-1{margin-right:5px !important}.me-2{margin-right:10px !important}.mb-4{margin-bottom:20px !important}.mt-2{margin-top:20px !important}.mt-1{margin-top:10px !important}.opacity-0{opacity:0 !important}hr{border:0;border-top:1px solid #ccc}.hide-scrollbar{overflow-x:scroll;scrollbar-width:none}.hide-scrollbar::-webkit-scrollbar{display:none}.d-none{display:none !important}.btn{display:inline-block;font-weight:400;line-height:1.5;color:#212529;text-align:center;text-decoration:none;vertical-align:middle;cursor:pointer;-webkit--select:none;-moz--select:none;-select:none;background-color:transparent;border:1px solid transparent;padding:.375rem .75rem;font-size:1rem;border-radius:.25rem;transition:color .15s ease-in-out,background-color .15s ease-in-out,border-color .15s ease-in-out,box-shadow .15s ease-in-out}.btn:hover{text-decoration:none}.btn-link{font-weight:400;color:#0d6efd;text-decoration:none}.btn-group-sm>.btn,.btn-sm{padding:.25rem .5rem;font-size:.875rem;border-radius:.2rem}.btn-outline-dark{color:#212529;border-color:#212529}.btn-outline-dark a{color:#212529}.btn-outline-dark:hover{color:#fff;background-color:#212529;border-color:#212529}.btn-outline-dark:hover a{color:#fff;text-decoration:none}.btn-outline-light{color:#f8f9fa;border-color:#f8f9fa}.btn-outline-light:hover{color:#000;background-color:#f8f9fa;border-color:#f8f9fa}.btn-secondary{color:#fff;background-color:#6c757d;border-color:#6c757d}.btn-dark{color:#fff;background-color:#001c4c;border-color:#001c4c}.btn-danger{color:#fff;background-color:#dc3545;border-color:#dc3545}.btn-light{color:#000;background-color:#f8f9fa;border-color:#f8f9fa}.btn-rounded{border-radius:50px}.btn-dark:hover{color:#ccc}.btn-outline-dark{color:#212529;border-color:#212529}.btn-outline-dark:hover{color:#fff;background-color:#212529;border-color:#212529}.btn-movie{font-size:25px;line-height:25px;padding:0;border-radius:50% !important;width:60px;height:60px;margin:0 15px 0 0;display:flex;justify-content:center;align-items:center}.btn-movie svg{width:30px;height:30px}.btn-icon{line-height:0}.btn-icon svg{fill:#fff;width:1.1em;height:1.1em}.btn-movie:hover svg{fill:#fff}.breadcrumb{font-size:16px;line-height:30px}.breadcrumb{display:flex;flex-wrap:wrap;padding:0;margin-bottom:1rem;list-style:none}.breadcrumb-item+.breadcrumb-item{padding-left:.5rem}.breadcrumb-item+.breadcrumb-item::before{float:left;padding-right:.5rem;color:#6c757d;content:"/";font-size:12px}.sidebar{display:flex;justify-content:space-between;height:100%;flex-direction:column}.sticky-box{height:100%;width:100%;margin-bottom:20px;padding:0}.banner{position:sticky;top:10px;margin-bottom:20px;margin-left:auto;margin-right:auto}.banner ins{position:sticky;top:10px;text-decoration:none;display:block;overflow:hidden !important}.banner ins:after{content:'PUBLICIDAD';background:#f5f5f5;width:100%;display:block;text-align:center;font-size:12px;line-height:12px;padding:4px 0}.bottom-ad-module{display:none}.roba-mobile{display:none}.roba-mobile,.roba-desktop{min-height:600px}.roba-desktop{display:flex;justify-content:start;align-items:end;flex-direction:column;width:320px;max-width:320px}.board-article-outbrain{margin-bottom:40px}.input-group{position:relative;display:flex;flex-wrap:wrap;align-items:stretch;width:100%}.input-group>.form-control,.input-group>.form-select{position:relative;flex:1 1 auto;width:1%;min-width:0}.input-group:not(.has-validation)>.dropdown-toggle:nth-last-child(n+3),.input-group:not(.has-validation)>:not(:last-child):not(.dropdown-toggle):not(.dropdown-menu){border-top-right-radius:0;border-bottom-right-radius:0}.input-group>:not(:first-child):not(.dropdown-menu):not(.valid-tooltip):not(.valid-):not(.invalid-tooltip):not(.invalid-){margin-left:-1px;border-top-left-radius:0;border-bottom-left-radius:0}.form-control{display:block;width:100%;padding:.375rem .75rem;font-size:1rem;font-weight:400;line-height:1.5;color:#212529;background-color:#fff;background-clip:padding-box;border:1px solid #ced4da;-webkit-appearance:none;-moz-appearance:none;appearance:none;border-radius:.25rem;transition:border-color .15s ease-in-out,box-shadow .15s ease-in-out}.form-control-sm{min-height:calc(1.5em+.5rem+2px);padding:.25rem .5rem;font-size:.875rem;border-radius:.2rem}.container{width:1140px;margin-left:auto;margin-right:auto}.top{margin-bottom:20px}.topbar-container{width:100%;background-color:#001c4c}.topbar{position:relative;display:flex;justify-content:center;padding:10px 0;z-index:2}.header-section{border-top:1px solid #fff;background-color:#eaede2;padding:10px 0;text-align:center}.header-section .header-section-title,.header-section .header-section-title a{font-family:"Poppins",sans-serif;font-weight:700;font-size:26px;line-height:26px;margin:0;padding:0;color:#001c4c}.menu-container{width:100%}.menu{position:relative;display:flex;justify-content:center;border-bottom:1px solid #ffffff59;padding:5px 0;z-index:2;background-color:#f3f3f3}.menu .navbar-nav{display:flex;flex-direction:row;list-style:none;padding:0;margin:0}.menu .navbar-nav .nav-link{display:block;padding:.5rem;text-decoration:none;transition:color .15s ease-in-out,background-color .15s ease-in-out,border-color .15s ease-in-out;color:rgba(0,0,0,.55);font-weight:500;font-size:14px;line-height:14px;text-transform:uppercase}.form-search-container{padding:15px 0;width:auto;background-color:#e9f1f8}.form-search{display:flex;flex-direction:row;justify-content:center;width:1140px;margin-left:auto;margin-right:auto}.form-search form{display:flex;width:50%}.form-search .input-search-autocomplete{background-color:#ffffffa8}.section{width:100%;margin-bottom:40px}.section .section-header{display:flex;align-items:center;justify-content:space-between;border-top:3px solid #001c4c;border-bottom:1px solid #001c4c;margin-bottom:20px}.section .section-header p,.section .section-header h2,.section .section-header h1{font-size:24px;line-height:28px;font-weight:bold;color:#001c4c;font-size:24px;line-height:24px;padding:10px 0;margin:0}.entity-item{display:flex;flex-direction:column;position:relative;width:100%;border-bottom:4px solid #001c4c;background:#f3f3f3;box-shadow:0 0 4px #000;text-align:left;margin-bottom:0}.entity-item .entity-item-details{order:1;padding:10px}.entity-item .entity-title,.entity-item .entity-title a{font-size:18px;line-height:20px;font-family:"Poppins",sans-serif;font-weight:600;color:#333;text-decoration:none;margin-bottom:0;margin-top:0;text-transform:uppercase}.entity-item .entity-title small{font-size:14px;line-height:16px}.entity-item .entity-title a:before{content:"";top:0;left:0;right:0;bottom:0;display:block;margin:0;padding:0;position:absolute;z-index:2}.entity-item .entity-item-image{order:0}.entity-item .figure{position:relative;aspect-ratio:.66666667;display:flex;justify-content:center;align-items:center;background-color:#222;color:#fff;overflow:hidden}.entity-item .figure:after{content:var(--category-var);position:absolute;bottom:5px;right:5px;font-size:14px;line-height:14px;text-align:right;background:#2e579e;color:#fff;font-weight:bold;padding:3px 6px;border-radius:5px}.entity-item .figure .img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover}.footer{background-color:#001c4c;padding:20px 0}.footer .container{display:flex;flex-direction:column;justify-content:center;align-items:center;text-align:center}.footer p{font-size:14px;line-height:1;color:#fff;text-align:center;padding:0 10px}.footer a{color:#ccc}.gallery{display:grid;grid-auto-flow:column;grid-auto-columns:calc(100% / 1.1);gap:10px;overflow-x:scroll;scroll-snap-type:x mandatory;scroll-behavior:smooth}.gallery figure{scroll-snap-align:start;position:relative;aspect-ratio:16 / 9;border-radius:10px;border:1px solid #ccc;display:flex;justify-content:center;align-items:center;background-color:#222;color:#fff;width:100%}.gallery img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover;border-radius:10px}.video-gallery{display:grid;grid-auto-flow:column;grid-auto-columns:calc(100% / 1.1);gap:10px;overflow-x:scroll;scroll-snap-type:x mandatory;scroll-behavior:smooth}.video{scroll-snap-align:start;border-radius:10px;overflow:hidden}.video iframe{width:100%;height:100%;aspect-ratio:16 / 9}.entity-gallery .gallery-row>*{border:1px solid #ffffff00}.entity-gallery .gallery-row{display:grid;grid-auto-flow:column;grid-auto-columns:calc(100% / 4.06);gap:15px;overflow-x:auto;overflow-y:hidden;scroll-snap-type:x mandatory;scroll-behavior:smooth;scroll-padding:0}.entity-gallery .gallery-row-6{grid-auto-columns:calc(100% / 5.9)}.entity-gallery .gallery-column{width:100%;scroll-snap-align:start;object-fit:cover}.entity-gallery .entity-item{display:flex;flex-direction:column;position:relative;margin-bottom:0;height:100%}.carousel-wrapper{position:relative}.carousel-button{position:absolute;top:50%;transform:translateY(-50%);background-color:#00000099;color:white;border:0;padding:10px 10px;cursor:pointer;z-index:10;border-radius:100%;display:flex;justify-content:center;align-items:center}.carousel-button svg{fill:#fff;width:20px;height:20px}.carousel-prev{left:0}.carousel-next{right:0}.accordion{width:100%;border:1px solid #ccc;border-radius:8px}.accordion-item{border-top:1px solid #ccc}.accordion-header{display:flex;justify-content:start;align-items:center;padding:15px;cursor:pointer;font-weight:bold}.accordion-header .badge{background-color:#6c757d;color:#fff;padding:5px 10px;border-radius:4px;font-size:14px}.accordion-checkbox{display:none}.accordion-content{max-height:0;overflow:hidden;transition:max-height .3s ease;padding:0 10px;background-color:#fff}.accordion-checkbox:checked ~ .accordion-content{max-height:500vh;padding:0 10px}.accordion-content .table{width:100%;margin-top:10px;margin-bottom:10px;border-collapse:collapse}.accordion-content .table td{padding:10px;border:1px solid #ddd}.accordion-item:first-of-type{border-top:0}.accordion-header::after{flex-shrink:0;margin-left:auto;content:"+";background-repeat:no-repeat;background-size:1.25rem;transition:transform .2s ease-in-out}.accordion-header h4{font-weight:normal}.accordion-content p{margin-top:0}.no-disponible{text-align:center}@media(max-width:1024px){.container{width:100%}.top{margin-bottom:0}.other-container{width:100%;margin:0;padding-left:15px;padding-right:15px}.col{flex:0 0 auto;width:50%}.menu{display:block}.aside-container{display:none}.form-search{width:100%}.form-search form{display:flex;width:100%;margin:0 15px}.entity-item .entity-title,.entity-item .entity-title a{font-size:16px;line-height:18px}.breadcrumb{margin-bottom:10px;padding-left:15px;padding-right:15px}.gallery{grid-auto-columns:calc(100% / 1.1)}.entity-gallery .gallery-row{grid-auto-columns:calc(100% / 2.3)}.section .section-header p,.section .section-header h2,.section .section-header h1{font-size:20px;line-height:22px}.roba-desktop{display:none}.roba-mobile{position:relative;top:0;margin-bottom:30px;display:flex;justify-content:start;align-items:center;flex-direction:column;width:calc(100vw - 30px);max-width:calc(100vw - 30px)}.roba-mobile ins{position:sticky;top:0}.bottom-ad-module{display:block;position:fixed;bottom:0;left:0;width:100%;margin:0;box-shadow:0 -1px 5px 0 rgba(0,0,0,.2);text-align:center;line-height:0;background:#f5f5f5;z-index:3000004;transition:transform .5s ease,opacity .5s ease}.bottom-ad-module-hidden{transform:translateY(100%);opacity:0}.bottom-ad-module .publi-box__close-btn{display:block;color:#666;background:#f5f5f5;z-index:1000001;font-size:17px;padding:5px;box-shadow:1px -2px 2px 0 rgba(0,0,0,.2);border-top-left-radius:8px;width:28px;height:28px;position:absolute;top:-28px;right:0;cursor:pointer}} .article{width:100%}.movie-header{position:relative;margin-bottom:40px;display:flex;flex-direction:row;align-items:flex-start}.movie-header .figure{position:relative;aspect-ratio:.66666667;display:flex;justify-content:center;align-items:center;background-color:#222;color:#fff;width:250px;flex:0 0 250px;overflow:hidden;margin-right:20px}.movie-header .figure .img{position:absolute;top:0;left:0;width:100%;height:100%;object-fit:cover}.movie-title-container{margin:0 auto;z-index:1;flex:1 1 100%;overflow:hidden}.movie-title-container .title{border-top:4px solid #001c4c;border-bottom:1px solid #ccc;font-weight:bold;font-size:36px;line-height:38px;margin:0;padding:10px 0;margin-bottom:20px;color:#001c4c;text-transform:uppercase}.movie-title-container .author-name{margin-bottom:30px}.movie-title-container .author-name a{font-weight:normal;text-transform:uppercase}.movie-title-container .categories{position:absolute;bottom:0;margin-bottom:0}.movie-title-container .categories-relative{position:relative}.movie-title-container .categories a{margin-bottom:10px;margin-right:5px}.movie-title-container .tagline{margin-bottom:20px}.movie-buttons{display:flex;align-items:center;margin-bottom:20px}.movie-buttons .btn-buy{font-size:20px;line-height:1;font-family:sans-serif;font-weight:normal;text-transform:uppercase;height:60px;justify-content:center;align-items:center;display:flex;padding:0 30px;border-radius:30px}.movie-buttons .discountPercentage{font-size:22px;line-height:22px;font-weight:bold;color:green}.movie-container{display:flex;flex-direction:row}.movie-body{margin:0;width:780px;flex:0 0 780px;overflow:hidden}.aside-container{text-align:right;width:320px;flex:0 0 320px;position:relative;margin-left:40px}.providers{width:100%}.providers .provider-container{margin-bottom:20px}.providers a{margin-right:10px;display:inline-block}.providers a:last-child{margin-right:0}.providers img{width:55px;height:55px;border-radius:5px}.providers .provider-type{display:block;background:#eaede2;padding:5px;margin-bottom:10px;font-weight:bold}.providers .provider-container:last-child{margin-bottom:0}.movie-info .row-info{display:flex;flex-direction:row;margin-top:10px;margin-bottom:10px}.movie-info .col-title{font-size:18px;line-height:24px;width:40%;flex:0 0 40%;display:flex;align-items:center;margin:0;font-weight:normal}.movie-info .col-title .icon{display:flex;margin-right:5px}.movie-info .col-title .icon svg{width:20px;height:20px}.movie-info .col-value{width:60%;flex:0 0 60%}.movie-info .col-value p{padding:0;margin:0}.movie-info .col-value .link{white-space:nowrap;text-overflow:ellipsis;display:block;overflow:hidden}.movie-share{position:fixed;bottom:10px;right:10px;z-index:1000}.movie-share .btn{font-size:25px;line-height:25px;padding:0;border-radius:50% !important;width:60px;height:60px;display:flex;justify-content:center;align-items:center;background:#064cc3}.movie-share .btn svg{width:30px;height:30px;fill:#fff}.circle-wrap{width:60px;height:60px;background:#ccc;border-radius:50%;margin:0 15px 0 0;z-index:1}.circle-wrap .circle{position:relative}.circle-wrap .circle .mask,.circle-wrap .circle .fill{width:60px;height:60px;position:absolute;border-radius:50%}.mask .fill{clip:rect(0,30px,60px,0);background-color:#000}.circle-wrap .circle .mask{clip:rect(0,60px,60px,30px)}.circle-wrap .inside-circle{font-family:sans-serif;width:49px;height:49px;border-radius:50%;background:#064cc3;color:#fff;position:absolute;z-index:100;font-weight:700;font-size:18px;line-height:18px;top:5px;left:5px;display:flex;justify-content:center;align-items:center}@media(max-width:1024px){.movie-body{width:100%;flex:0 0 100%;overflow:unset}.movie-header{flex-direction:column}.movie-header .figure{margin:0;width:100%;flex:0 0 100%;background-color:transparent;aspect-ratio:unset;padding:20px 50px}.movie-header .figure .img{position:relative;height:auto;box-shadow:0 0 10px 0 #333}.movie-title-container{width:100%;margin:0;padding-left:15px;padding-right:15px;text-align:center}.movie-title-container .title{border-top:0;font-size:26px;line-height:30px;margin:0 0 20px 0}.movie-buttons{flex-direction:column;margin-bottom:30px;border-bottom:1px solid #ccc;padding-bottom:20px}.movie-buttons .btn-buy{margin-bottom:10px}.movie-title-container .categories{position:relative}.movie-container{margin:0;padding-left:15px;padding-right:15px}.movie-info .row-info{flex-direction:column}.movie-info .col-title,.movie-info .col-value p,.movie-info .col-value a{margin:0}.movie-info .col-title{width:100%;flex:0 0 100%;font-weight:600}.movie-info .col-value{width:100%;flex:0 0 100%}}
In 1921, five years after the appearance of his comprehensive paper on general relativity and twelve years before he left Europe permanently to the Institute for Advanced Study, Albert Einstein visited Princeton University, where he delivered the Stafford Little Lectures for that year. These four lectures constituted an overview of his then-controversial theory of relativity. Princeton University Press made the lectures available under the title The Meaning of Relativity, the first book by Einstein to be produced by an American publisher. As subsequent editions were brought out by the Press, Einstein included new material amplifying the theory. A revised version of the appendix "Relativistic Theory of the Non-Symmetric Field," added to the posthumous edition of 1956, was Einstein's last scientific paper.
Albert Einstein
Albert Einstein nació en Ulm, Alemania, en 1879, y trabajó como funcionario en la Oficina Federal de Patentes de Berna. En 1905 publicó una serie de trabajos en los que, entre otras cosas, dejó expuesta su revolucionaria teoría de la relatividad restringida, determinante en la física del siglo xx. Premio Nobel de Física en 1921, ante la ascensión del nazismo se vio obligado a abandonar Alemania en 1933 e instalarse en Estados Unidos, en el famoso Institute for Advanced Study de Princeton. Hasta su muerte en 1955, Einstein destacó por su lucha activa contra la proliferación de las armas nucleares. Además de mi visión del mundo (Fábula 42, ahora también la colección Metatemas), Tusquets Editores ha publicado su Correspondencia con Michele Besso (1903-1955) (Metatemas 36), un apasionante epistolario con su amigo íntimo, y el estudio de Luis Navarro Veguillas Einstein, profeta y hereje (Metatemas 21), que analiza las grandes aportaciones de Einstein a la física.
Ver ficha de Albert Einstein »