Browsing search results for "observe microwave background".

Lost in the vastness of space

Tonight I co-gave the opening address at the Templeton Foundation supported Q3 conference on Cosmology and Theology. It was perhaps the most nerve wracking talk I’ve ever given. While I am a Christian, I must admit to being terrified of conservative Christians. I’ve just realized I can’t count the number of churches who have made [...]

The Improbable Universe

Slide Show + Audio (.mp4)
Transcript: This is a talk I originally prepared to present as part of the 2206-2007 convocation series at Illinois College. Since then I have given it before several other audiences, and with every presentation I’ve had more people ask, will this be online. Finally, I can saw yes. Here’s the link. [...]

Time is T + 500,000,000 years
Stars – Go, Galaxies – Go
Keck, De-ionization is underway

In what is to me the most scientifically important paper of the year, astronomers today announced the discovery of 2 galaxies at redshifts > 10 and 4 galaxies with redshifts >7.7. The most distant of these galaxies was forming stars just 500,000 years after the Big Bang and ~120,000 years after the formation of the cosmic microwave background, and contributed to the re-ionizing the universe after the formation of neutral hydrogen. These galaxies were discovered using the Hubble Space Telescope and Keck II, and by taking advantage of gravitational lensing effects in three galaxy clusters. (Figure shows a selection of Hubble Space Telescope images of the cluster fields with the newly-located sources marked. credit: Stark et. al / STScI / ESA)

That was a lot of exciting information, and now that I’ve gotten some of the excitement out of my system, let me step back and tell you exactly what it means.

Cosmic Backlighting: The Cosmic Microwave Background

This is the second part in what I had originally seen as a two part series on what may be the neatest tools in astronomy’s tool belt for indirectly examining the stuff of the universe. I say originally thought, because as I sit here writing, I’m thinking this is going to evolve into three parts. In this entry I want to address where is CMB came from and how it tells us where we’re going. (image credit: NASA / WMAP Science Team)

Pick up pretty much any astronomy text, look up Cosmic Microwave Background, and you’ll find something along the lines of: “The Cosmic Microwave Background is a relic of the moment the universe cooled enough for recombination to take place. Prior to that moment the universe was opaque to radiation. Today we see this left over radiation as a 2.725 K degree microwave background radiation.” The book will then go onto explain how the CMB was detected.

Did any of that make sense to you? I know it didn’t make sense to me the first dozen or so times I read it over the years. Let me see if I can make sense of this scientific obstruction for you.

Gravitational Lenses: Making the invisible detectable

Astronomers on Earth are limited in how they can look at the universe. We basically have three tools. We can detect light across a broad spectrum of colors. We can capture high energy particles – cosmic rays – that are flung at us from distant events. We can also potentially measure gravity waves (but we’re still sorting out that technology). In all three instances, we are limited by our technology’s sensitivity to an event. This means that faint, small, low energy stuff at any significant distance is invisible as far as our detectors are concerned. And stuff like dark matter… well… it can’t be directly detected at all. When direct detection of something is impossible, it becomes necessary to find indirect methods. We are like Plato, looking to understand reality but only able to see shadows dancing on a cave wall.

Two of the most well defined ways we have of studying the universe’s shadows are the Cosmic Microwave Background (CMB) and gravitational lenses. Both things are scientifically interesting in their own right, and each can be used to indirectly see otherwise invisible content in the universe. Recent papers have shown how the CMB may allow astronomers to study our own solar system’s Oort Cloud (the source of long period comets), and how gravitational lensing effects can be used to map dark matter. Rather than try and discuss both these topics in one post, I’m going to take on gravitational lenses today, and dig into the cosmic microwave background tomorrow. (image credit: Kneib & Ellis w/ Caltech Digital Media Center)

Redshifted Formaldehyde

I just finished taking a tour through the latest papers posted on the astronomy preprint server. In general, few things do more to attract a my attention than a good title. One title in particular stopped my casual scrolling dead on its pixels: Redshifted formaldehyde from the gravitational lens B0218+357. Now, I knew beforehand that formaldehyde – the chemical people who store dead things used to use to preserve their specimens – existed in clouds of interstellar material. Other than knowing it is out there, I have to admit that I really don’t know why anyone cares that it exists beyond the “Oh neat” factor. So… I stopped to read the paper. (Image: CASTLES Survey)

You are the Center of the Universe (and so am I, and so is Gursplex on Alpha Eck)

One of the concepts that confuses people most about the Universe is the Earth’s location relative to the Big Bang. People constantly ask, “Where is the center of the Universe?” and “Where was the Big Bang relative to us today?” and perhaps the most articulate of all, “Why does the Cosmic Microwave Background appear in all directions if it came from the Big Bang?” We are creatures accustomed to life in a three dimensional universe, and it is extraordinarily difficult to visualize our place in space. It is even harder to visualize that every place in space was once at the center of the Big Bang. (image credit: NASA/WMAP Science Team)

And it came from the CMB . . .

Fraser (my co-host over at Astronomy Cast) and I like to joke about how everything we know in astronomy we know because of the Cosmic Microwave Background. How do we know the universe formed during the Big Bang? The CMB. How do we know the cosmic geometry is flat? The CMB. How do we know the mass distribution of the Oort Cloud? The CMB. How do we know where babies come from? The CMB.

Okay, so that last one is an exaggeration. As far as I know, human babies and the CMB have nothing in common. The remark about the Oort Cloud, however, may not always be as far fetched as it sounds. A group of scientists working at the Harvard-Smithsonian Center for Astrophysics, and lead by David Babich, have theorized a new technique for determining the mass distribution in the Oort cloud using distortions in the Cosmic Microwave Background.