Great Concept Art Piece By Neil Blevins

Space Station View of the Full Moon

Credit: NASA & ISS

How do we know light is a wave?

Before I answer this question, I’ll need to briefly go over a wave property called superposition. Basically, superposition is the idea that two waves can be in the same position at the same time, and interfere with each other:

When the two waves add to each other and make a larger wave, we call this constructive interference. When the waves cancel each other out, we call this destructive interference. 

Now we’re going to move on to the Double Slit Experiment. Basically, you shine a beam of light at a piece of metal, cardboard, etc with two slits in it, with a surface behind it where you can see the light hit it. 

If light is a wave, what we’d expect to see would be an interference pattern created by the light from the first slit interfering with light from the second slit, which is exactly what we see. It’s a pattern of constructive interference (brighter regions) and destructive interference (darker regions), looking like this:

These images are helpful:

that is how we know light acts as a wave!!

Aerospace Engineering Magazine  April 1962

NASA and Veterans

November 11 each year is a day we honor those who have served in our nation’s armed forces. 

Discover how we have close ties to the military, even to this day, and see who has traded in their camouflage uniform for an astronaut flight suit.

There have been veterans working for us since the beginning, even when it was still called the National Advisory Committee for Aeronautics (NACA). 

Additionally, there are several active duty military members working at NASA facilities through special government programs.

Today, there are more than 1500 veterans currently employed with us. Their experiences in the military make their expertise invaluable around the agency. We value the unique leadership style they bring to the work place.  Above and below are some astronaut veterans.

A Partnership for the Space Age

Since the early days of NASA, we’ve partnered with all branches of the military. We still work closely with the military today and rely on the expertise of our service members to support our missions both while in active duty and in the civilian workforce. Here are some examples of this close partnership:

The Marines helped with recovery efforts of Astronaut Alan Shepard at the end of his sub-orbital flight on May 5, 1961…a task performed across several of our missions.

Today, the Navy helps us recover spacecraft, just like the Orion space capsule…which will one day carry astronauts into deep space and eventually on our journey to Mars. 

…and the Air Force has traditionally and continues to help us transport sensitive and critical space hardware around the globe. 

The Coast Guard has even helped us access remote locations to collect oceanographic data as part of our efforts to study and learn more about the Earth. 

We’ve partnered with the Army to use their unique capabilities at the Yuma Proving Ground to test the entry, descent and landing of our spacecraft systems.

To all the Veteran’s out there, we thank you for your service to America and your continued support of America’s space program.

Happy Veteran’s Day!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Solar

What are comets made of?

Our planet seen from Saturn, captured by the Cassini spacecraft

Image credit: NASA / Cassini

don’t assume the gender of my HYDROGEN! ok