What can you say about the past four decades?

The temperature of the globe has been ever increasing over the past 4 decades. We have also seen the rise of deforestation and etc. However, we have also seen advances in scientific technology that solves many complications. A very increasing field would be genetic modification or crispr and biomedical. Technology is also ever advancing into shaping the way we use gadgets. Internet access is no longer considered a privilege but a necessities to drive the economies running and keeping the nation economically stable. Many nations are now also heavily investing in space technologies for expedition to planet mars for the search of living things. In the past decades, renowned cosmologist Stephen Hawking has released many publications relating to Black holes etc. He had also went to talk about the existence of aliens and extraterrestial lifeforms and how the world may come to the end because of aliens. This is not a exhaustive lists of the events happened over the past 4 decades but it gives you brief through about the many contributions that the scientific community has given. Thus, this is all.

It’s the energy source of stars

What are the options? physical property can be color, smell, opacity, viscosity, density, infra red spectrum, melting and boiling points, attraction and repulson to magnets, etc.