I will give you the shortest answer that I know and then explain what it means:

The galaxies are too tightly wound up!

Had such a big explosion actually occurred that many billions of years ago, stars should be evenly distributed throughout space. However, they are found in tightly-wound balls or spiral galaxies. They have not had time to spread out.

The stars that make up the Milky Way Galaxy, the galaxy in which we live, rotate about the galaxy's center at various speeds. However, the inner stars rotate faster than the outer stars do.

The speeds at which these stars rotate are much too fast to support the suggestion that our universe is billions and billions of years old. Real science, to the contrary, supports the accessible evidence that shows we live in a young universe rather than an old universe.

Here is why.

The stars' rotation speeds, which have been scientifically observed, are so fast that if our galaxy were more than four hundred million years old, it would be a featureless disc of stars with great voids of space existing between them.

Evidence that can be observed today by studying the Milky Way Galaxy actually indicates a much younger universe. In fact, all observed galaxies are either tightly-wound spiral shapes, as with the Milky Way, or in tightly-bunched balls of stars.

A recent example that bears this out was provided by the Hubble Space Telescope, which is mounted in an observatory that orbits the earth. This powerful telescope found an extremely detailed spiral shape of stars inside of the central hub of what is known as the "Whirlpool" galaxy, M51.

This and other such discoveries are in direct conflict with the predictions that are made by old-universe cosmologies, which are that the universe is billions and billions of years old.

These scientific findings are a serious problem for these billions-of-years beliefs and for Darwinism, which has to be based on billions of years of time for Darwinian-style evolution to have any hope of validation.

According to secular, old-universe astronomy, the Milky Way is supposed to be more than ten billion years old. The problem for Darwinism is that this age is about forty times longer than the spiral-shaped galaxies should have held to these tightly-wound patterns.

Although scientists have known of this situation since the 1950's, the public does not hear much about it. Darwinian scientists refer to it as the winding up dilemma. They cannot explain it. And this dilemma is a problem that is not about to go away as it is a problem that applies to all other galaxies as well.