It is time to test your memory. Can you remember the time you felt colder than any other time in your life? What was the air temperature? Was it above or below 0°F?

Let's test your brain cells even more. What is the coldest air temperature ever recorded on the Earth? Where was this low temperature recorded? (Answers are provided in a few moments)

Now, let's travel into space to see if we will get any colder. Do you think it would really be colder in space than on the Earth? How cold?

Let's see how well you answered the questions. Only you know the coldest temperatures you personally experienced. The coldest recorded temperature on Earth was -132°F. (That's -91°C). This low temperature occurred in Antarctica in 1983. Brrrr! We encounter an interesting situation when we discuss temperatures in space. Temperatures in Earth orbit actually range from about +120°C (+250°F) to -120°C (-185°F). The temperature depends upon whether you are in direct sunlight or shade. Obviously, -185°F is still colder than our body can safely tolerate. Thank goodness (and thank NASA science) for well-designed space suits that protect astronauts from these temperature extremes.

The space temperatures just discussed affect only our area of the solar system. Obviously, it is hotter closer to the Sun and colder as we travel away from the Sun. Astronomers estimate temperatures at Pluto are about -210°C (-350°F). How cold is the lowest estimated temperature in the entire universe? Again, it depends upon your location.

We are taught it is supposedly impossible to have a temperature below absolute zero, which is -273°C (-459°F). At this temperature, atoms do not move.

Scientists have successfully cooled down a gas to a temperature barely above absolute zero. These two scientists (Cornell and Wieman) won a Nobel Prize in Physics in 2001 for their work - not a discovery, in this case.

In the 1920s, Satyendra Nath Bose was studying an interesting theory about special light particles we now call photons. Bose had trouble convincing other scientists to believe his theory, so he contacted Albert Einstein (yes, that Albert Einstein). Einstein took Bose's ideas about light particles and applied them to atoms of certain gases. Einstein's calculations helped him theorize that atoms would behave as Bose thought - but only at very cold temperatures. This theory is now called the Bose-Einstein Condensation Theory.

This theory becomes even stranger (you might even say weird) at this point. These "condensates" are not the same as the matter we studied in science classes. Do you remember being taught that all matter is a solid, liquid, or gas? Bose-Einstein condensates cannot be considered as any of these forms of matter. They are studied as a special part of physics known as "quantum mechanics" - a science using probability rather than an absolute answer. Scientists now believe there may be actually around 100 states of matter.

The two scientists who won the 2001 Nobel Physics Prize were able to cool the atoms successfully to a Bose-Einstein condensate. They had to add a step to their experiment that would hold the atoms together as they changed. They had to use laser beams and special magnetic traps to hold them together. Voila - it worked! The rest, shall we say, is history!

When atoms form a Bose-Einstein condensate, they all seem to move in "lock step." In other words, all atoms act exactly the same. Can you imagine everyone on Earth raising their hands at the same time or sneezing at exactly the same moment? That's what these Bose-Einstein atoms do.

People can easily wonder why anyone would ever want to do this type of experiment. How can we use such information? One answer is that such an experiment simply puts one more of Einstein's theories to the test.

Scientists have also discovered that ultra-cold atoms can help them make the world's atomic clocks even more accurate. These clocks are so accurate today they would only lose one second every six million years! Such accuracy will help us navigate better in space because distance is velocity times time (d = v x t). With the long distances involved in space travel, we need to know time as accurately as possible to get accurate distance.

You may not enjoy this last idea about better timekeeping because if it occurs, you may no longer have an excuse for being late. Of course, you could still rely on your own watch, which can never be as accurate. You can still use it as an excuse when you are late, if it is set wrong.