“Scientists actively approach the door to knowledge–the boundary of the domain of what we know. We question and explore and we change our views when facts and logic force us to do so. We are confident only in what we can verify through experiments or in what we can deduce from experimentally confirmed hypotheses.” –Lisa Randall (Knocking on Heaven’s Door)
“Although there is much we don’t yet know about the evolution of the universe, we have a spectacularly successful understanding of the universe’s evolution based on the so-called Big Bang theory supplemented by a period of exponential expansion of the universe known as cosmological inflation… This theory has agreed with a range of observations, including observations of the microwave radiation in the sky–the microwave radiation left over from the time of the Big Bang.
“Originally the universe was a hot dense fireball. But during the 12.75 billion years of its existence it has diluted and cooled substantially, leaving this much cooler radiation that is a mere 2.7 degrees kelvin today–only a few degrees Celsius above absolute zero. Other evidence for the Big Bang theory of expansion can be found in detailed studies of the abundances of nuclei that were made during the universe’s early evolution and in measurements of the universe’s expansion itself.” –Lisa Randall
“In some cases, we will understand the observations sufficiently well to know what they imply about the underlying nature of matter and physical laws. In other cases, we’ll spend a lot of time unraveling the implications. Regardless of what happens, the interplay between theory and data will lead us to loftier interpretations of the universe around us and expand our knowledge into currently inaccessible domains.
“Some experiments might yield results soon. Others could take many years. As data come in, theorists will be forced to revisit and sometimes even abandon suggested explanations so we can improve our theories and apply them correctly… even when new results might require abandoning old ideas.
“Our hypotheses are initially rooted in theoretical consistency and elegance, but… ultimately it is experiment–not rigid belief–that determines what is correct.” –Lisa Randall