I suppose that you think to physicists.
A physicist
D. matter or energy. Scientists classify everything in the universe as either matter (atoms, molecules) or energy (light, heat).
Energy
Scientists are working to harness geothermal energy by tapping into heat sources beneath the Earth's surface to generate electricity and heat buildings. This renewable energy source is sustainable and can provide a constant and reliable source of power.
you think we wont tell u!!!!
Humans need energy for different purposes. Electricity is simply a convenient way to transport energy.
Matter cannot be created or destroyed. It can only be changed from one form to another. However, Einstein and other scientists have shown us that matter and energy are interchangeable. Matter is changed into energy in the sun and in other nuclear reactions, (E = mc2).
A good example of visible energy is found in the stars. An example of invisible matter is the "dark matter" that scientists believe surrounds galaxies. So, one answer to the question would be "in and around galaxies".
I think the question is a bit mixed up, but I think this is the answer. Scientists talk about "mass-energy" as a unified thing. Just after the Big Bang "energy", in the form of radiation energy, was dominant. However, today it seems that "mass" is the dominant form. In other words, "matter" now dominates the Universe. There is the complication of "Dark Matter" and "Dark Energy". Cosmologists still don't really know what these are. So that puts some uncertainty into this discussion of matter and energy. Some scientists believe that it is now "energy" that dominates, because of the discovery of Dark Energy. (Also, cosmologists think that both "matter" and "anti-matter" were created, but that there was a slight imbalance in favour of matter and the anti-matter seems to have been destroyed, leaving just "matter".)
Currently, dark matter cannot be harnessed as an energy source because it does not interact with light or other forms of electromagnetic radiation. Scientists are still studying dark matter to understand its properties and potential uses in the future.
If they are astronomers, they classify everything as 'interesting'. I think the answer may be something like "matter or energy". In fact, according to Relativity Theory, mass (of matter) and energy are in many ways equivalent. "Mass-energy" is a term often used to refer to this fact. Pretty well everything in the Universe is matter or energy,
I am a chemist, and I don't personally know of any scientists who are doing this. but some scientists I know are worried about this method. well as you probably know there are pro's and con's of using hydrothermal resources.