GPS uses Quasars

GPS uses Quasars to work

GPS uses quasars to get its own position
GPS satellite in low Earth orbit. Credit: NASA artist’s impression
The Global Positioning System (GPS) is precise.

That precision originates in a mind-blowing place!

GPS signals tell billions of people where they are each day.

GPS helps pilots land planes and captains steer ships.

GPS signals stamp locations onto millions of photos.

GPS gives you driving directions.

But, where does GPS get its own GPS?

The GPS for GPS

How does GPS know where a GPS satellite is?Click here to continue reading…

Merry-Go-Round Earth shows Seasonal Constellations

Welcome Starry Night event visitors! We built this fun, interactive model of the merry-go-round Earth on the evening of March 3rd, 2018 around a real campfire. Read on for the background and teaching method.

The Earth is like a Merry-Go-Round

Merry-Go-Round Earth model demonstrating how the seasonal constellations work
A Merry-Go-Round is a good model of daily Earth rotation.

The Earth is like a merry-go-round showing us seasonal constellations

That iconic childhood ride. Round and round each day we go, round and round each year we go, where we stop nobody knows! When we look out from the edge of the ride we can see the space beyond. Sometimes the Sun occupies that space, and sometimes that space is the night sky filled with stars.Click here to continue reading…

Walk to Mintaka

Physical Astronomy by Daniel Cummings
Mistakable rises toward the zenith as you walk toward the equator
As you walk toward the equator, Mintaka appears to rise higher in the sky.

In this post we will learn how to use one bright star of Orion’s belt to visualize the Earth’s equator.

Mintaka is a Star in Orion’s Belt

When you look up at the winter sky in the northern hemisphere, Orion and his famous belt are impossible to miss. The belt is made up of three stars of equal brightness.

One of these stars is called Mintaka and it is a guidepost for finding the Earth’s equator in space. Click here to continue reading…

Tilt Head to Tilt Earth

Physical Astronomy by Daniel CummingsTilt your head to tilt the earth and experi nice the seasons

Seasons are caused by a tilted Earth

Use this technique to understand how seasons happen on the Earth. The Earth is tilted. When the northern part (your forehead and eyes) tilts away from the Sun the season is winter. When the northern part tilts toward the Sun the season is summer.

The Earth is tilted as it spins daily – it is not straight up and down like a top, but more like the Leaning Tower of Pisa (if the tower could spin!). As it goes through its yearly orbit, the Sun hits the northern and then the southern parts of the Earth.

Tilt your head to tilt the Earth

In this model, when the northern part (your forehead and eyes) tilts away from the Sun the season is winter. When the northern part tilts toward the Sun the season is summer.

Did you like this season model? Any questions? Type in the comments to send me a message.

Train your Brain – See the shape of the solar system

Physical Astronomy by Daniel Cummings.

Train your Brain - See the solar system disk

See the solar system from Earth

Most people, when they look up at the night sky can easily see stars and identify some familiar groups of stars (asterisms and constellations). Some people can even find and name some planets – Venus, Jupiter, and Mars are all bright and easy to see.

But, there are many invisible wonders in the sky – and some of them can be seen without a telescope. In fact they are so big that a telescope is not the right tool to use; we have to use something even more powerful… imagination!

Using visualization and imagination, I am going to show you how to find and “see” a very large structure in our sky: the solar system disk itself.

Click here to continue reading…

What Looks Like Sunset

English: The sunset seen from Shwesandaw Pagoda in Bagan, Myanmar. Date 9 December 2014, 17:23:27 Source Own work Author Jacklee Camera location 21° 09′ 49.23″ N, 94° 51′ 58.11″ E Heading=76.098113207547° Is what looks like sunset really the sun – “setting”?

What is that thing that happens every day that makes it look like sunset?

Can you change your mind easily? Are you flexible enough to understand that the same set of observations and facts can lead two different people to two different conclusions?

For a long time, everyone on the Earth thought the Sun was moving and the Earth was staying still. This is just what it looks like and anyone who dared to suggest a different view might easily be considered odd, or worse, dangerous. Having the benefit of hundreds of years of scientific evidence and wisdom to back up my observations, I now have the luxury of believing that it is the Earth that is moving and that the Sun is the one standing still.

It is fun to imagine being carried through space on the surface of a giant ball. Definitely better than staying still while the sun careens through the sky each day. With this image in my mind, I feel the Earth is carrying me away from the view of the Sun.

Sunset should be called “away sun” and not “sun set” because it is me moving, not the sun. It is me being carried away into the shadows forming behind the bulge of the Earth, not the Sun setting. I am riding the Earth with its great round bulk between me and the Sun.

It’s NOT a sunset but me… rushing backwards… at 1000 mph as the bulge of the earth grows in between.

I propose “awaysun” as the new name for sunset and “towardsun” as the name for sunrise. These new names help solidify the idea that we are the ones moving.

What do you think?