Neptune does not clear Pluto's orbit.

[oil pan 4]

Some, maybe a little helium fusion occurs but it takes much higher temperatures, like 5 or 6 times hotter than the suns core. When the hydrogen burns out the star collapses in on its self, greatly increasing core temperature and pressure until it reignites. Then the star expands way bigger, because it's a lot hotter because when the star reignites on helium it burns a good portion of its helium in a few seconds.
They burn hydrogen for billions of years, helium for millions of years, carbon for centuries, neon for years, oxygen for around a few years or less depending on size, silicon for a day, then collapses to make iron nickel for a few seconds and if it's big enough after iron and nickel it goes boom.

[Xist]

Do iron and nickel usually go boom?

[freebeard]

Off-topic:

California is a 'stanktuary' state.

Sorry, carry on.

[oil pan 4]

Originally Posted by Xist

Do iron and nickel usually go boom?

In a star about 10x the size of the sun it does

[All Darc]

Well, I use to ask myself why the sun today have intensity similar to 200 million years ago, if today it have less hydrogen.
Any intensity change for sunlight would change things dramactically on Earth.

Or maybe it have change or cycles that lead to ice ages.

What USA will do will the next ice age arrive???

Originally Posted by redpoint5

I never understood why a less energetic sun would be larger. Also, why would the sun wait until it exhausted H2 before it began fusion of He? Shouldn't both processes be occurring simultaneously?

[Xist]

Legend says the U.S. is doing everything possible to prevent another ice age.

What would it take for Venus to experience an ice age? Would it actually need ice, or just freezing temperatures?

Oil Pan, how is the weather? ENMU keeps sending me text messages about campus closures, etc., but they haven't said why.

We had 60+ MPH winds on Monday and the lame towns near the New Mexico border had 70 - 75 MPH winds. A friend's family set up a trampoline just last week and the wind blew it onto their roof. Last week someone mentioned a trampoline being blown down the street and I wondered how to anchor them.

I wish that my friend's family had taken precautions.

[oil pan 4]

It's was about 9 degrees this morning it snowed 6 to 8 inches yesterday. This is nothing to me as I lived in Maine for 4 years and northern Japan for 3 years.
Everyone else is freaking out. I went to work before the sun came up no problem.

Originally Posted by All Darc

Well, I use to ask myself why the sun today have intensity similar to 200 million years ago, if today it have less hydrogen.
Any intensity change for sunlight would change things dramactically on Earth.

Or maybe it have change or cycles that lead to ice ages.

What USA will do will the next ice age arrive???

The sun output increases about 10% every billion years as the hydrogen burns off and the temperature increases to burn the lower concentrationof hydrogen.

[Xist]

I do not feel that the temperature would increase in order to burn a dwindling supply of oxygen. I feel there must be a more logical explanation.

[freebeard]

Originally Posted by All Darc

What USA will do will the next ice age arrive???

Floating cities in active solar melt-water lakes on top of the 2 miles of ice.

[Xist]

This article explains that as the sun burns hydrogen and helium sinks to the center, the area where fusion happens expands, so more fusion happens at a given time, and as it heats up, fusion happens faster: Our Sun Is Lighter Than Ever, And The Problem Is Getting Worse