HS-ESS1-2 The Big bang

ESS1.A: The Universe and Its Stars

• The study of stars’ light spectra and brightness is used to identify compositional elements of stars, their movements, and their distances from Earth.

• The Big Bang theory is supported by observations of distant galaxies receding from our own, of the measured composition of stars and non-stellar gases, and of the maps of spectra of the primordial radiation (cosmic microwave background) that still fills the universe. 

• Other than the hydrogen and helium formed at the time of the Big Bang, nuclear fusion within stars produces all atomic nuclei lighter than and including iron, and the process releases electromagnetic energy. Heavier elements are produced when certain massive stars achieve a supernova stage and explode.

PS4.B Electromagnetic Radiation

• Atoms of each element emit and absorb characteristic frequencies of light. These characteristics allow identification of the presence of an element, even in microscopic quantities.

Energy and matter

• Energy cannot be created or destroyed - only moved between one place and another place, between objects and/or fields, or between systems.

Interdependence of Science, Engineering, and Technology

• Science and engineering complement each other in the cycle known as research and development (R&D). Many R&D projects may involve scientists, engineers, and others with wide ranges of expertise.

Order and Consistency in Natural Systems

• Scientific knowledge is based on the assumption that natural laws operate today as they did in the past and they will continue to do so in the future.

• Science assumes the universe is a vast single system in which basic laws are consistent.

Constructing Explanations and Designing Solutions

• Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

Science Models, Laws, Mechanisms, and Theories Explain Natural Phenomena

• A scientific theory is a substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment and the science community validates each theory before it is accepted. If new evidence is discovered that the theory does not accommodate, the theory is generally modified in light of this new evidence.