Science and Technology

Why do radioactive materials like plutonium in nuclear waste continue to pose a threat for many thousands of years?

How things work

Who invented solar cells to harness the Sun's energy?

How things work

How fast can a helicopter fly?

Outer Space

Which is the most dangerous stage of a manned spaceflight?

Living Creatures

How do hummingbirds manage to hover in mid-air?

World

How did Adolf Hitler spend his last few days before committing suicide?

Outer Space

What are gravitational waves? Do they really exist?

Science and Technology

Did medieval alchemists have magical powers to form gold out of cheaper metals?

Outer Space

What is the chemical composition of the Sun? How do astronomers identify the types of elements it contains?

Human Biology

Since evolution still continues, will man grow bigger head in the future?

Human Biology

What makes us thirsty? Is it dry mouth or dehydrated body tissue that signals thirst?

World

Which are the top ten countries with petroleum reserves?

Science and Technology

What is the difference between cluster bomb and conventional bomb?

Outer Space

Why is Jupiter’s moon Europa believed to have life under its surface?

How things work

Why does a slice of bread dolloped with honey on one side bend like a concave lens?