Photo Research in Action Ata Sarajedini, Ph.D.

To Galaxies and Beyond

Ata Sarajedini, Ph.D.
professor,
Charles E. Schmidt College of Science
1. What establishes the axis and direction of spin of spiral galaxies in 3 dimensional space?   

The axis and spin direction of spiral galaxies are random. They are set by the initial rotation axis and rotation velocity of the gas cloud from which the galaxy formed.

2. Couldn’t we go to the Trappist system in the next 100 years? We build an advanced AI ship with enough fusion energy to power the ship with millions of embryos, eggs and sperm that are 'hatched' when the ship gets there and educates them on how special they are. Fiction? If realistic, why hasn't it already happened?   

My opinion is that this scenario is unrealistic within the next 100 years — maybe 500 years?

3. Do you feel we are unique? It seems that statistics and that life exists here would imply that it exists everywhere in the universe with water, heat, and more dense molecules.   

If you’re asking about life elsewhere in the universe, then I think it is very likely that we are not the only life in the universe. As you suggest, just given the large numbers of galaxies, stars and planets that likely exist out there, there must be life somewhere else besides Earth. For an idea of the numbers we are talking about, check out this episode of Astronomy Minute: Is There Life Elsewhere in the Universe?

4. Measuring the metal enrichment in pulsating stars: is this a measure of quantity only or does it allow you to determine the number of types of metals that the star contains?   

It’s only a measure of quantity of metals not the types of metals.

5. Didn’t Tycho Brahe’s observations help validate the Crab Nebula’s age?    

No, given the very small angular size of the Crab Nebula in the sky, Tycho would have needed a telescope to observe it, and he did not make his observations with a telescope.

6. What proof do we have that the big bang actually happened?   

In the language of science, I think what you are asking is “what evidence do we have that the big bang actually happened?” To find out, listen to the following episodes of Astronomy Minute (astronomyminute.org):
What is the Big Bang?
What is the Cosmic Microwave Background?
What is the Hubble Law?