PV Gap

Ray Said:

Sequence these words from largest to smallest: Milky Way, Solar System, sun, local group, Universe.?

We Answered:

Sun, Solar System, Milky Way, Local Group, Universe

Opps, got it reversed. Just read it backwards

Tina Said:

Solar System, Sun, and Race...legit question?

We Answered:

The sun has two important effects on skin (among others): (1) UV radiation destroys folic acid (a vitamin) and (2) UV radiation helps create vitamin D3. The first is a bad thing, the second is good.

Human populations living near the equator, where sunlight is plentiful, have dark skin for protection against the damaging effects of the sun's UV rays while still absorbing enough to create vitamin D3. Human populations living far from the equator have light skin to absorb more UV rays to aid the production of vitamin D3 since there is less sunlight to cause damage.

These are only overall trends; there are exceptions. Fish and sea mammals are foods high in vitamin D3, so populations far from the equator that have diets rich in these will tend to have darker skin because they don't have the vitamin deficiency.

Annie Said:

If our Sun Passes through the Spiral of the Milky Way galaxy would it effect our Solar System Sun and Earth?

We Answered:

It's been speculated that when the solar system passes through the plane of the galaxy, the gravitational attraction of all those stars disrupts the Oort Cloud and greatly increases the risk of planets being struck by comets. The evidence for this is not conclusive. It last happened about 3 million years ago and will happen again in about 30 million years. Passing through the plane is not a sudden event but a process that lasts for hundreds of thousands of years.

Sergio Said:

How old are the following- The solar system, the sun, origin of man & the earliest civilization?

We Answered:

Solar system, including the Sun and the Earth: 4.6 Ga (billion years)
Genus Homo is generally considered to be the human race: 1.5 to 2.5 Ma (million years)
The term "Civilization" is not precise.
Tools were first used around 3 Ma, but note that todays apes and even dolphins and crows use tools.
Language arose sometime between 2 Ma and 40 ka
Agriculture developed around 8500 BCE
First cities were around 5000 BCE
Writing developed by 3000 BCE

Christopher Said:

How can i make my project model of the solar system?

We Answered:

I am in the 8th grade too. You could use bendable wire that you can probably buy at Home Depot. If you can not find it there try to see if anyone has any that you know.