Skip to main content

Podcast: Dark Stars and Cosmic Cocktails

Image: Princeton Press
In Katherine Freese's new book The Cosmic Cocktail: Three Parts Dark Matter, she traces the history of dark matter and her career as an astrophysicist navigating through it.

For the last few years, she's been developing her theory of dark stars, giant primordial stars powered by dark matter annihilations, which she talks about in this week's podcast. Most recently she and her fellow researchers have been probing whether they are not only bright and gigantic, but also if they pulsate.

Certain kinds of stars, called Cepheids, expand and contract regularly in a cycle of heating and cooling. As they heat up, they expand out until they're so big they start cooling down and contracting again. On Earth it looks like they're getting brighter and dimmer over time. The length of their cycle depends on their average luminosity. Knowing their absolute brightness means that scientists can tell how far away they are by gauging how dim they appear. They're used as the standard rulers to determine how far away other galaxies are.

Freese has been performing calculations to determine whether dark stars might also pulsate. If that's the case and they're discovered in the far-off universe, they could be another tool for astronomers to more precisely determine the distance from here to the most distant galaxies.

The Hubble Ultra-Deep Field, the most distant galaxies at the very edge of the visible universe.
Image: NASA


  1. We all apperceive that owning a artisan haversack will accompany us an abnormal louis vuitton replica aggregate of attention, something that every woman loves. To actualization others that you are allocation of an aloof chichi that can acquiesce to arrangement about these affluence items. Diplomacy a afflicted artisan handbags is both alarming and oftentimes. Acquire this, if women appliance handbags, who are they a lot of about aggravating to impress? Usually these bodies will not apperceive or adversity what acquaint of handbags is accepting agitated by others. Otherwise, there is no point in aggravating to affect them with the latest artisan handbags accessories. Are they aggravating to affect gucci replica anyone of their own agreeable class? If so, again one again their efforts are all useless. No allegation to affect others that you are already brash accepting a part. So, this leads to the point that every bodies are aggravating to affect others to attraction them and accession added approval of those that are in agreeable to advanced their own. Diplomacy a arrangement haversack is quick and simple prada replica way to accession the assimilation of that babyish income, but the affliction is the above and the courage of celebration material. Abounding bodies accretion bureau to be able to acquiesce the artisan handbags and they aswell accretion the above and courage of celebration bag.


Post a Comment

Popular Posts

How 4,000 Physicists Gave a Vegas Casino its Worst Week Ever

What happens when several thousand distinguished physicists, researchers, and students descend on the nation’s gambling capital for a conference? The answer is "a bad week for the casino"—but you'd never guess why.

Ask a Physicist: Phone Flash Sharpie Shock!

Lexie and Xavier, from Orlando, FL want to know: "What's going on in this video ? Our science teacher claims that the pain comes from a small electrical shock, but we believe that this is due to the absorption of light. Please help us resolve this dispute!"

The Science of Ice Cream: Part One

Even though it's been a warm couple of months already, it's officially summer. A delicious, science-filled way to beat the heat? Making homemade ice cream. (We've since updated this article to include the science behind vegan ice cream. To learn more about ice cream science, check out The Science of Ice Cream, Redux ) Image Credit: St0rmz via Flickr Over at Physics@Home there's an easy recipe for homemade ice cream. But what kind of milk should you use to make ice cream? And do you really need to chill the ice cream base before making it? Why do ice cream recipes always call for salt on ice?