Questions Series: How do we know the size of the Universe?

A set of questions I get from kids and adults alike while doing my Astronomy in Action planetarium shows consists of the following: Does the Universe have an end? How big is the Universe? Where is the center of the Universe? What is the ‘Observable Universe?’ How is it different from just saying ‘the Universe?’ First of all, let me say that it is really hard to imagine the Universe as it is, even with a solid understanding of large-scale Physics.  This is because there is no analogy in our lives, no reference point in our everyday experience.  It’s very...

Amazing NYT Mars feature and thoughts on the Universe

You have to see this incredible feature on Mars, showing some of the best High-Res photos and milestones from the mission. http://www.nytimes.com/interactive/2014/12/09/science/space/curiosity-rover-28-months-on-mars.html As you look through the images, remember that you are looking at another world.  It feels foreign, yet oddly familiar.  You almost want to reach out and just grab a handful of sand.  It makes you realize that we are not the center of the Universe. There are likely Billions of worlds similar to Mars, with Dunes and Soil and Skies and Mountains, except those world may not be so barren.  They may be lush and alive, dominated...

Just a Little Video of The Entire Universe

The Universe is big, in case you weren’t aware.  It’s the biggest thing we know of, containing at least 100 Billion Galaxies, each with up to 1 Trillion of their own stars.  It’s ludicrously large. How do we know its so big? A major project completed in 2001 surveyed the Galaxies of the local Universe, and what was found can be summed up in the video below, from Reddit. The data is from the 2 Micron All Sky Survey (2MASS), whose goal was to map all the galaxies in the known Universe in Infrared.  The colours in the above map show...

Uncanny Alignment Across Billions of Light Years

Quasars are Galaxies with incredibly massive Black Holes at their centre.  These Black Holes are fuelled by a swirling disc of material that can be ejected in a long jet along their axis of rotation, all due to the conservation of angular momentum.  This accretion disc can be so hot that it causes the central region of the Galaxy to shine more brightly than the entire Galaxy of stars surrounding it. A Belgian team using the Very Large Telescope (VLT) studied a population of 93 Quasars spread over Billions of Light-Years, and noticed that the rotation axes of the Quasars...

What is the largest Galaxy in the Known Universe?

I sometimes forget just how big things can be in the Universe.  And I often forget just how small and insignificant we are in the grand scheme of things.  Then I see a Galaxy like IC 1101 side by side with our own and I very quickly remember. About 350 Million light years from Earth IC 1101 is the largest galaxy in the known Universe in terms of actual size. If you didn’t notice the image above, it shows our own Milky Way Galaxy as a little tiny dot in the bottom left corner, and then Andromeda our closest neighbour,...

Hubble Ultra Deep Field – Amazing Image!

You need to see this animation.  It’s an amazing picture showing the Hubble Ultra Deep Field and the small patch of sky Astronomers had to aim at in order to photograph it.  The moon is there for comparison.  The patch of sky is about the size of a grain of sand held at arm’s length. Courtesy of gfycat.com, it really puts things in perspective.  The crazy part is that if you look in any direction in the universe, in patches of sky as small as this one, you see the exact same thing.  There are more galaxies in the Universe than we...

Against the Grain: NASA Says Half of All Stars Are in Between Galaxies

NASA had announced a press conference for yesterday afternoon to reveal amazing findings that would ‘change how we look at galaxies.’  And they did just that, sort of. Findings from the Cosmic Infrared Background Experiment (CIBER) reveal that there is a huge surplus of Infrared light present in the vast darkness that exists between Galaxies.  Infrared light is invisible to the human eye, but is emitted by most room temperature objects.  It fills the EM spectrum at wavelengths longer than visible light (See yesterday’s post for the EM spectrum).  This surplus of light is greater than what we would expect from galaxies...

Galaxy’s Ring of Star formation shines face on

I’ve seen a lot of lovely images from  the Spitzer Space Telescope.  It takes infrared images and can see the fine structure of galaxies, where stars are forming and where they are not forming.  The photos paint a picture of the history and evolution of a galaxy.  The latest image released last week shows some amazing features. The Cyan light in the image is a combination of blue and green coloured light representing infrared wavelengths of light at 3.4 and 4.5 microns.  This wavelength shows the stellar population in the galaxy.  The red light is representing dust features that glow...