Jun
11
2008

Odds and Ends are back

From time to time as I gather up the questions from the on-site Scientist on the Spot features we find some good questions that don’t connect well to the featured researcher. Here are some of those questions.

Why are stars circles?

Iapetus' equatorial ridge
Iapetus' equatorial ridgeCourtesy NASA
I am assuming you mean, why are they round or spheres? It’s because of gravity. The larger something is (or the more mass something has) the more gravity it has. That gravity pulls equally in, so that’s why stars and planets are round, gravity makes them that way. The fancy-pants scientific name for this is isostatic adjustment.

But the Earth, for example, is not a perfect sphere – it bulges out in the middle because of its rotation. Smaller asteroids are oddly shaped because they don’t have enough mass to produce the gravity necessary to pull them into spheres. Some planets are oddly shaped too, and scientists are not sure exactly why. Saturn’s moon Iapetus is a great example. It is for some reason shaped more like a walnut and has an equatorial ridge that scientists cannot come to a conclusion as to how it formed.

What is a pimple?

Well, our skin has pores which are connected to glands that produce sebum – like an oil. Sebum is a good thing - it acts to protect and waterproof our skin, and keeps it from becoming dry. When these pores get blocked by dirt or dead skin (which we shed constantly) the secretions of sebum that would normally come from the pore are blocked and build up. These can become infected with bacteria which causes pimples to form.

The harder question is for me – to pop or not to pop. I can’t resist popping a pimple – it is a character flaw that has resulted in me sporting many a wound worse than the original zit. A great “how to pop a pimple” step-by-step is posted here.

Why do beans make us fart?

When food gets to your large intestine it is eaten by the 200+ different species of bacteria that live there and target parts of the food our stomach and small intestines can't digest, and gasses such as methane, hydrogen and hydrogen sulfide are produced as a by-product. Beans contain several sugars that we can’t digest, so lots of gas is produced by bacteria eating the otherwise indigestible material.

What is the scientific name for a pig?

Sus scrofa domestica.

What is the moon?

The big whack
The big whackCourtesy NASA
You mean besides being the only natural satellite of the Earth and the cause of the tides and so forth?

I think that the Earth collision theory (also known as the Big Whack) for the creation of the moon is the coolest, and is the one that is the most accepted today. The hypothesis goes that a Mars-sized (Mars is less than half the size of the Earth) planet collided with Earth a looooooooooong time ago and the debris that was created orbited around the damaged Earth and formed into the moon through a process called accretion – or the growth of large bodies like the moon by gravitationally attracting more matter. So the little bits of debris were attracted to bigger and bigger bits as the bigger bits had more gravity. As we learned above, the spherical shape arises from gravity as well. It is believed that as a result of the collision the smaller planet (Theia) was destroyed, ejecting its mantle into space while its core sank into Earth’s core.

Did you know that the moon is in synchronous rotation with the Earth? That means it keeps nearly the same face turned towards the Earth at all times.

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Allowed HTML tags: <a> <h3> <h4> <em> <i> <strong> <b> <span> <ul> <ol> <li> <blockquote> <object> <embed> <param> <sub> <sup>
  • Lines and paragraphs break automatically.
  • You may embed videos from the following providers vimeo, youtube. Just add the video URL to your textarea in the place where you would like the video to appear, i.e. http://www.youtube.com/watch?v=pw0jmvdh.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Images can be added to this post.

More information about formatting options