Answers to Science Questions

When you have DNA left on a piece of clothing, how do modern techniques match the DNA with the guilty suspect?

Are solar panels on spacecraft mistaken for UFOs sometimes? - Matthew has emailed us with an addition to an answer last...

I've heard that there's a single origin for the emergence of Homo sapiens. Is there any scientific background...

What is the possibility of erroneous matching of DNA? There was a case I saw about 8 years ago in which a man was...

I've heard that bone marrow transplants can cause havoc with DNA testing. Is this the case, and if so, how can the...

Is there any such thing that could erase or change DNA?

Why is it that we like drinks with gas, like beer or coke? If we drink these beverages without it, they taste bad, but...

What's gravity made of?

Is it true that someone's head would explode if you went out into space without a helmet on?

Is it possible to see a gamma ray burst in the sky? I saw something in the sky flash on and off one night.

We're told that photons can't escape from a black hole, and I was wondering if gravitons can escape from a...

How far is the nearest galaxy?

How do scientists check the distances between planets, and how accurate are their methods?

From a scientific rather than a religious point of view, why should there be a universe? Why isn't there just...

How do scientists measure the life of the sun?

How many human years are there in a light year?

If our weight is the difference between gravity and the centrifugal force of the Earth's rotation, why are we not...

He sent us an email correcting an answer given last week about the best place to put a carbon monoxide detector.

How is thunder and lightning made, and what causes it?

Why is it that cream crackers left out take a matter of a few hours to go soggy and stale, yet when put into a large...

If human and worm DNA are so similar, why are we so different?

I have a stepson who has fragile X syndrome. He was diagnosed at the age of eight and is 28 now. I'm interested in...

How many different types of DNA can you get?

Why is it that some children are born with dark hair and then go very fair when they get older, and similarly, why do...