The Scientific Community (Edexcel A Level Physics): Revision Note

Validating Experimental Results

• The scientific community works together to ensure that the knowledge and understanding of scientific concepts are kept as up to date as possible

  • This comes from continuous experimenting based on evolving knowledge and new developments in technology

• For example, one of the early models of the atom was the 'plum pudding model' by JJ Thompson

  • Emerging evidence later found by Ernest Rutherford established that most of the atom was actually empty space

  • This lead to an evolved understanding of what the atom looks like, which is still being investigated to this day

• Scientists ask questions, suggest answers (hypothesise) then test these suggestions

  • This is known as the scientific process

The Scientific Process

1. Ask a question about why something happens or how it works e.g. why does light diffract?

2. Suggest an answer by forming a theory (a possible explanation of the observation) e.g. light is a wave

   • This could also be in the form of a model or a simplified picture of what is physically going on e.g. the spreading out of waves

3. Make a prediction or hypothesis

   • This is a testable statement, based on the theory, about what will happen if it is tested

   • For example, if light is a wave, it is expected to reflect and refract

4. Carry out an experiment to test the hypothesis

   • This will provide clear evidence to support the initial prediction

   • For example, investigating the reflection and refraction of light - if the experiment doesn't match the theory, the theory must change

Validating Scientific Knowledge

• A theory is only scientific if it can be tested

• Any pieces of experiment evidence must be published

  • This is often in scientific journals and reports (papers)

• The papers are peer-reviewed by the scientific community in the same field

  • Other scientists examine the data and results, ensuring that there has been a fair test and the conclusion from the results is reasonable 

  • This also ensures that work published in journals is of a good standard

• This process helps validate scientific knowledge and ensure integrity (trustworthiness)

  • Scientists can be dishonest or biased, leading to invalid conclusions from their experiments

  • For example, manipulating the data to fit with their hypothesis

• Peer-review isn't perfect, and often independent scientists test the theory themselves to cross-check the results and make sure the original results weren't just a 'fluke'

• If the evidence then supports a theory, the theory is accepted (for now)

  • If many experiments back this theory with good evidence, and it is not yet deemed incorrect, then the theory is considered a scientific 'fact'

• However, scientific theories are never indisputable

  • There can be breakthroughs and advances to provide new ways to test the theory which could lead to new evidence and conflicts

  • When this happens, the testing happens all over again, the theory is adapted to the new evidence found

  • The best theories are those that scientists are continuously trying to poke holes in and test thoroughly. If the theories survive many different tests, then it is more trusted

• The nature of scientific knowledge is therefore continuously changing and evolving