1.2 Video: How big is big history? 1.2 Video: Wie groß ist die große Geschichte? 1.2 Vídeo: ¿Cómo de grande es la historia? 1.2 Vidéo : Quelle est l'importance de la grande histoire ? 1.2 ビデオ大きな歴史とはどれほどのものなのか？ 1.2 Wideo: Jak duża jest wielka historia? 1.2 Vídeo: Quão grande é a grande história? 1.2 Video: Büyük tarih ne kadar büyüktür? 1.2 视频：大历史有多大？

How big is big history? How do we think of human on cosmic scales? Comment penser l'homme à l'échelle cosmique ? Well, only recently, we learned how old the universe is. It's roughly 13.8 billion years and to get some feeling of the magnitude of that timescale, we can use the metaphor of compressing the whole history of universe to a single year. Il s'agit d'environ 13,8 milliards d'années et, pour avoir une idée de l'ampleur de cette échelle de temps, nous pouvons utiliser la métaphore de la compression de toute l'histoire de l'univers en une seule année. If we would do that, then the universe would start at new year's eve with a big bang, but we only would see the first light from that cosmic explosion after 20 minutes. Si nous faisions cela, l'univers commencerait à la veille du nouvel an par un big bang, mais nous ne verrions la première lumière de cette explosion cosmique qu'au bout de 20 minutes. And then the first few months, everything would be dark and then spring the first class and galaxies would emerge. Les premiers mois, tout était sombre, puis au printemps, la première classe et les galaxies apparaissaient. Our own Sun and the solar system would appear around September 1st, including the planet Earth and life on Earth would evolve pretty soon. By October, we would have bacteria. We would have single cellular life and kind of complex organisms, multicellular organisms like sponges would only appear midway through December. In fact, it's the last week of December that's really exciting. By Christmas, the dinosaurs would appear and they would be wiped out by December 30th. À Noël, les dinosaures apparaîtraient et seraient anéantis le 30 décembre. The last two days of the year would actually see the evolutions of mammals, as we know and other life forms. And us human beings, modern human beings, only appear at the very last six minutes of that year. Kind of regular history with written records and agricultural settlements would be the last 30 seconds of that year, and modern history from Columbus to the birth of the scientific revolution to all the wars would be the very lost seconds of that year. L'histoire ordinaire, avec les documents écrits et les établissements agricoles, correspondrait aux 30 dernières secondes de cette année, et l'histoire moderne, de Christophe Colomb à la naissance de la révolution scientifique, en passant par toutes les guerres, correspondrait aux toutes dernières secondes de cette année. We think in terms of time scales, but we can also think in terms of space and then actually we can go on both directions. Human beings and everyday object are roughly midway between the very large structure of the universe as a whole, and the smallest structure of subatomic particles. Les êtres humains et les objets du quotidien se situent à peu près à mi-chemin entre la très grande structure de l'univers dans son ensemble et la plus petite structure des particules subatomiques. In fact, if you think about stars on everyday scale. En fait, si l'on considère les étoiles à l'échelle de tous les jours. For instance, this great food could be a star, could be our own Sun. Par exemple, ce grand plat pourrait être une étoile, pourrait être notre propre soleil. And then planet Earth would actually be one of these peppercorns, roughly a hundred times smaller. La planète Terre serait en fait l'un de ces grains de poivre, environ cent fois plus petit. But in fact, to get a good feeling of the distances, at these scales, planet Earth, this little peppercorn would be at a distance of ten meters from the Sun, this grapefruit. Mais en fait, pour avoir une bonne idée des distances, à ces échelles, la planète Terre, ce petit grain de poivre serait à une distance de dix mètres du Soleil, ce pamplemousse. And at these cosmic scales, light would move very slowly. In fact, it would take 8.5 minutes for light to traverse the distance from the Sun to the Earth. So one question is if this is the Sun, how far do you have to move to meet the next star, Alpha Centauri? Space is really empty if this is the Sun here in Amsterdam, then the next star will be in Russia. In fact, it will be Moscow. 3,000 kilometers further down and that's only the next star. In our Milky Way, there are a hundred billion stars. Dans notre Voie lactée, il y a cent milliards d'étoiles. And to get a sense of that magnitude, you should think of a star now as a grain of sand and then the Milky Way would be a big pile of sand, roughly a few hundred billion stars and that's only our local galaxy. Pour se faire une idée de cette ampleur, il faut considérer une étoile comme un grain de sable et la Voie lactée comme un gros tas de sable, soit environ quelques centaines de milliards d'étoiles, et il ne s'agit que de notre galaxie locale. The universe, the visible universe, the part of the universe that we can see through our telescopes contains roughly a hundred and billion of these galaxies. So, a hundred billion piles of sand. That's only the part of the universe that we can see and it could very well be that the actual universe is much larger. In fact, it could even be infinite. If you go the other direction now and we think of space from the point of view of a subatomic particle, then we could think again of this grapefruit, but now would be the nucleus of an atom. In fact, an atom would have several of these grapefruits together and we could think you were here in Amsterdam, we could think of then as an atom as the size of the city of Amsterdam. En fait, un atome contiendrait plusieurs de ces pamplemousses et nous pourrions penser que vous êtes ici à Amsterdam, nous pourrions considérer qu'un atome a la taille de la ville d'Amsterdam. So, it would have these grapefruits and then there would be a few electrons flying around through the city. On that scale, a cell the unit of biology say, think of the smallest human cell or a human blood cell would be roughly the size from the Earth to the Moon. And if we think about ourselves from the point of view of an elementary particle, we would be a thousand times big as from the distance from the Sun to the Earth. Et si nous nous considérons du point de vue d'une particule élémentaire, nous serions mille fois plus grands que la distance entre le Soleil et la Terre. We would be bigger than the solar system. So from that perspective, we are both very small and our human history is just a minute fraction of the whole cosmic time scale. But from another perspective, we are actually big, because it's actually us humans living on this small planet Earth who figured out just in a few hundred years in this very last second of the cosmic year. Mais d'un autre point de vue, nous sommes en fait grands, car c'est nous, les humains vivant sur cette petite planète qu'est la Terre, qui avons compris en quelques centaines d'années, à la toute dernière seconde de l'année cosmique. The full evolution of this universe and it's us from this everyday space skills who have figured out both the largest structures in the universe, and the smallest particles. L'évolution complète de cet univers et c'est nous, à partir de ces compétences spatiales quotidiennes, qui avons compris à la fois les plus grandes structures de l'univers et les plus petites particules. So from that prospective actually, I think we, as human beings can feel pretty big. De ce point de vue, je pense qu'en tant qu'êtres humains, nous pouvons nous sentir très grands.