Monthly Archives: August 2017

Ep 45: It takes two dead stars to make gold?

It takes two dead stars to make gold?

In episode 43, we talked about how our universe makes the chemical elements that our world and we are made of through processes like nuclear fusion, and exploding stars. That may not be enough. Elements like platinum gold and uranium might come from the collision of two neutron stars, possibly the only way to have enough neutrons handy.

Here’s a video simulation of two neutron stars colliding to form a black hole.

Watch 2 Neutron Stars Merge

Here’s an article on when such a collision was observed in this, our real world.

Collision of dead stars produced the world’s gold

Ep 44: What stars are made of

What stars are made of

In order to find out what a star is made of, pass its light through a prism, and examine the resulting rainbow, or spectrum.

Here’s an article that includes an app that will let you play with the effect of different chemicals on a spectrum.

Absorption/emission lines

And here’s the history, with names and dates, on how we figured out this particular trick.

Spectral Lines and the History of Spectroscopy

Ep 43: Pop go the stars

Pop go the stars

For our universe to produce minds, we require many different chemical elements. Those elements were created by the stars. The lighter elements fuse together and provide the energy for stars to shine, and to keep from collapsing under their own gravity. Heavier elements, anything heavier than iron, require the stars to go pop—to explode into super novas which create the rest of the heavy elements.

Here’s a page on Nucleosynthesis, the process that created the chemical elements that make up our planet, and us.

Nucleosynthesis – The Physics Hypertextbook

There is some debate as to exactly when the first stars formed.

Here’s a page on an estimation of when the first stars formed based on data collected by NASA’s WMap satellite.

When did the first stars form in the universe?

Here’s a page with a different time, based on data collected by the European space agency’s Planck satellite.

First stars formed even later than previously thought

Ep 42: It’s bigger than we thought

It’s bigger than we thought

In 1923 Edwin Hubble used a variable star to prove that the Andromeda Nebula was actually the Andromeda Galaxy. Before his measurements, it was widely believed that our galaxy, the Milky Way, was the only island of stars in the universe. Boy, did we get it wrong!

Have a look at NASA’s page about when they pointed the telescope named after Edwin Hubble at the star he used to measure the distance to M31—Andromeda.

Hubble Views the Star That Changed the Universe

Ep 40: A matter of perspective

A matter of perspective

How do we know how far away the stars are? For relatively nearby stars, other than our own sun, we can use a trick of perspective called parallax. This gives rise to a unit of distanced called the parsec, roughly equivalent to 3.26 lightyears.

Ep 39: Size, distance, and the solar eclipse

Size, distance, and the solar eclipse

From the earth’s surface, it can be difficult to tell how big or far away objects in the solar system are. From the earth’s surface, as illustrated by yesterday’s total solar eclipse, the moon and sun are the same apparent size.

Here’s a slightly cheesy YouTube video that describes a method for measuring the actual size of our sun.

Let’s Measure the Diameter of the Sun!

And here’s an article on measuring the sun, that includes other sections describing ways and means of measuring within the solar system.

Size of the sun

Ep 37: The sound of the big bang

The sound of the big bang

Today we take a closer look at the sound of the big bang © John g. Cramer – 2003, which he created from the data gathered by the WMAP satellite.

Here’s his original article on the subject.

Here are a bunch of versions of the sound of different lengths, and updated versions he created from the data gathered by the Planck mission in 2013.

You can also check out his home page, his Analog articles, and his science fiction novels—”Twister,” and “Einstein’s Bridge.”

Ep 36: When rocks go boom

When rocks go boom

In 2013, a 10 to 11 ton rock exploded in the skys over Russia. That came in handy when I wanted an explosion sound effect. As Long as I used it, I may as well make an episode out of it.

Here’s a video of the event, and a couple of articles about it.

Meteorite shards hit Russia after explosion in the sky

Russia’s meteor explosion was as powerful as 400,000 tonnes of TNT

Chelyabinsk meteor mystery 3 years later