Why do scientists assume that the early universe was much hotter and denser than the universe of today?

What is warmer during the night: land or sea/ocean?

two small balls are suspended on parallel threads of the same length so that they touch each other in the vertical position. the mass of the first ball is 0.4kg and the mass of the second ball is 200g.

A solid cylinder with a mass of 266 kg and radius 0.070 m is rotating with an angular speed of 83.0 rad/s about an axis passing through its center and perpendicular to its end faces.

Glacial episodes are an example of

When a jumbo jet slows and descends on the approach to landing, there is a decrease in both its kinetic and potential energy. where does this energy go?

In a series circuit, loads which have the same voltage dropped across them will have?.

When a brick is dropped from the roof of a house, it lands on the ground with a speed v. What will the speed at ground level be for an identical brick dropped from a roof twice as high as the first one?

The scientific method begins with recognizing a problem. The recognized problem in this scenario is, "Why is the printer in the office not working?" Choose the hypotheses that are testable and from which an experiment can be formed.

The correctly balanced equation for H2O2 → H2O + O2 is

How would an unbalanced chemical equation convey misleading information about what took place during a chemical reaction?