Physical Astronomy by Daniel Cummings
Seasons are caused by a titled 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.
Life Stars – Visible Exoplanets
Physical Astronomy by Daniel Cummings
A “Life Star” is a visible star that could host life. This is a name I came up with in February 2017 (around the time of the TRAPPIST announcement) to describe visible stars with confirmed planets orbiting in the habitable zone. “Life Star” is easier to say and explain. I hope it catches on! Continue reading “Stars like ours – 9 bright “Life Stars””
Physical Astronomy Tool by Daniel Cummings
It’s Groundhog Day!
What better way to celebrate Groundhog Day than to Build your own Groundhog Day Shadow Tracker
Let’s do some Physical Astronomy. The experience will help you to understand the movement of the earth and sun through the seasons. You will build a scientific instrument that is also a fun garden decoration and you will be able to track the Groundhog’s Shadow all Spring!
Continue reading “Groundhog Day Shadow Tracker”
An amazing thing is about to happen! A Star in a Star will be born.
You can witness the birth of a new star in the night sky. The new Star already has a birthday: 2022!
According to scientists, the new star will form when two stars that are orbiting each other grow so close that they merge into one.
The new star will appear in the constellation Cygnus. You can see the approximate location marked by a red circle in the Stellarium screenshot here:
The image of the two blue stars on the home page of this Star in a Star site shows what scientists think it looks like now. This impressive video shows an artist’s rendering of the star merge.
In the pair, one star is larger than the other so in the end, there will be a new star… A Star in a Star.
PHYSICAL ASTRONOMY BY DANIEL CUMMINGS
Face the sun.
Point your right hand toward the Sun.
Now point your left hand toward the Sun.
Both hands should be pointing at the sun.
Now, turn a little bit to the left, keeping both hands pointing at the sun.
Swing your left arm out until it is pointing in the opposite direction from the sunset. Bring your hands together again and repeat this swinging motion.
Bring your hands together again and point them both at the sun. This time, instead of swinging, bounce your left hand, leftward, some number of times… (14 is perfect if you can do it) …until it is pointing in the completely opposite direction from the Sun at sunset. Your left hand should now be pointing East.
Was the moon at any one of those 14 hand bounce spots? That is the age of the moon in days.
Please post your questions in the comments!
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?