Monday, February 9, 2009

What's Up? The four fundamental forces of the universe

Welcome back to What's Up?

During the past month methane was found in Mars' atmosphere. This methane may have been created either by Martian organisms or more likely, natural chemical reactions occurring inside Mars. Methane breaks down very quickly in Mars' atmosphere, lasting only a few years before dissipating. This means that methane is continually being replenished. NASA is now working on designing a new spectrometer that could detect whether the methane is being created by unknown life forms or by natural chemical processes.

Chemical interactions are occurring on Mars and everywhere else in the universe right now. These interactions are what allow every human being to live. What allows interactions to even take place?

As physicists currently understand, there are four fundamental forces that allow interactions to take place. The forces are gravity, the electromagnetic force, weak nuclear force, and strong nuclear force.

Gravity, the most well known force, also happens to be the most mysterious. It can act across vast distances and holds everything in our universe together, yet it is the weakest force. It is ten to the power of thirty-eight (one followed by thirty-eight zeros) times weaker than the strong nuclear force (the strongest force) and is the only force that can act upon all types of particles.

Gravity is also the only force without any detected particle to mediate it between particles. It has been theorized that "gravitons" transfer the force between particles but usually physicists refer to gravity as the bending of space-time as first proposed by Albert Einstein in his General Theory of Relativity.

The second weakest force is the weak nuclear force. Even though it is called the weak force it is still ten to the power of thirty-five (one followed by thirty-five zeros) times stronger than gravity.

The weak nuclear force governs beta decay. Beta decay is when a neutron (non-charged particle in an atom) transforms into a proton (positive charged particle in an atom). This force is communicated with W and Z bosons (obviously named by someone who needs a little more fun in their life).

The electromagnetic force, which may be somewhat familiar to some people, is a force that has effects observable in everyday life. Electromagnetism is everywhere, from fridge magnets, to roller coaster brakes, to every molecule in your body. The electromagnetic force affects all charged particles in the universe.

This force allows magnetic fields to form, such as the one around the Earth that protects life from radiation from the sun and other places in space.

Electricity and magnetism used to be considered two separate forces but eventually were found to be two aspects of the same force. This was proved when it was shown that the flow of electricity causes a magnetic field and vice versa.

The electromagnetic force is communicated with photons or virtual photons. Photons are what we perceive as light particles.

Finally, the strongest of the forces, is the strong nuclear force. It is the force that holds the particles within protons and neutrons together. Without this force, protons and neutrons wouldn't be able to form and since there would be no protons or neutrons, atoms wouldn't be able to form.

The four forces govern how our universe behaves; let's see what these interactions will lead to in the skies this month.

The full moon is on Feb. 9 this month and will shrink to a new moon by Feb. 25.

Venus will reach its greatest brilliancy for the year and is visible near the western horizon shortly after sunset. Through a telescope Venus will appear as a large crescent. It's definitely worth checking out if you have access to a telescope.

The Athena Community Astronomy Club's monthly meeting will take place on Feb. 22 at the Wilmot Community Center. It starts at 7pm and ends at 9pm. Guests are always welcome.

Finally, the morning before the meeting, just before sunrise on the 22nd, is a spectacular grouping of the Moon, Mercury, Jupiter, and Mars. They will be best visible about 30 minutes before sunrise. Mars will be hiding very low in the eastern horizon with brilliant Jupiter above and to the right of it. Mercury, which is rarely ever visible, will be to the right of Jupiter and the thin crescent moon will sit a little farther off to the upper right in the sky.

Until next month, just look up!

Hey Kids...
Remember Spirit and Opportunity, the two "Tonka truck" rovers on Mars? Spirit and Opportunity were supposed to operate for about three months but are still operating after over five years on Mars! Opportunity is still operating as if it is almost good as new, but Spirit has been having some troubles lately. It's troubles started one day when scientists sent commands for what Spirit should do that day. Spirit received them, but it never moved. Then Spirit had trouble figuring out which direction it was looking. Finally, Spirit started having memory problems. Hopefully Spirit is just being a little stubborn and will get back to exploring Mars soon.

No comments: