The link between science education and early childhood education is still blurred. This is so because many science education researchers apparently, but mistakenly, believe that the way young children interrogate and investigate the world around them is not appropriate for their understanding of scientific concepts. Although there is an effort among early childhood teachers to be aware of how young children explore the world around them, there still consists considerable uncertainty about how they learn and develop while immersed in classroom science activities. To understand learning processes in early childhood science, this study followed a group of five-year-old children enrolled in a public early childhood center in Belo Horizonte (Brazil) while they participated in a science unit jointly designed by teachers and the children. The study was designed to understand the world through the children's eyes (i.e., their "lifeworlds") and how this world expands while they engage in science. We use the theoretical category of experience to investigate how children, immersed in the social practices of inquiry, expand their lifeworld while engaging with each other, with the adults present and with the material world. Our findings show: (a) the importance of producing a common ground, that is, a sense-giving field contexture that allows actions and speeches to make sense; (b) how the movements of the participants through transactions allow the emergence of an experience that stands out and remains; and (c) how "an experience" might leads to learning and expansion of the participants' lifeworlds.