NASA's COBE satellite measured the cosmic microwave background's spectrum and mapped tiny variations in its temperature. Krishna Choudhary and Lester Nare explain why an almost uniform sky still contains clues to the early universe. Those measurements helped establish the observational foundation for later, more detailed maps of the microwave background.
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COBE measured a background spectrum closely matching a blackbody.
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Small temperature differences revealed structure within the nearly uniform background.
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Later missions built on COBE's measurements with more detailed maps.
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1:24:23really not categorized the map across the sky, right? The the sky is this 360° on all sides. We'd like to now see is the cosmic microwave background the same over here as over here. Is the light coming from the big bang the same over here or over here and over here and over here? Turns out yes, up to a very small margin, the light is almost exactly the same. And it proves that this sort of cosmic black body spectrum, right, the universe was like a giant ball of gas, not giant, a tiny small ball of gas that was completely in equilibrium with itself. Um, and it proved that like these temperature anisotropies are
1:25:04perhaps what give structure later on. like these tiny fluctuations in the temperature of the cosmic microwave background is what gives us all of the structure that we see today with galaxies, us, you know, it's it's insane. And on the right hand side at the top, you see the Kobe satellite image and on the bottom NASA sent out further um refinements of that satellite to to get smaller and smaller structural detail. And it's really cool because you can see a blurred image of the baby universe and then as we turn the resolution dial up >> it's the same image but now we're getting a clearer picture. >> It's a little more granularity. Yeah. >> And for those interested in mass uh sky
1:25:44surveys generally check out Krishna's interview with Dr. Michael Blandon who I might say is one of the godfathers of largecale digital sky surveys during his leadership of the Sloan digital sky survey among other things. >> Yes. Yes. And these guys won the 2006 Nobel Prize in physics. >> We are moving to 1991 discovery of allactory receptors. Crazy that it 1991 is not that long ago. >> Not that long ago. But this is how we figured out how our nose works, right? Um, what are the chemical receptors that bind to specific smells and give us the sense of smell? Neuroscientists Linda Buck and Richard Axel at Columbia University, they
1:26:26identified the genetic foundation of that sense of smell and they discovered this massive multi-gene family of a thousand different odorant receptors that are now in our nose. They earned the 2004 Nobel Prize in Medicine. We are going to jump forward to 1992 to 1998 discovery and structural elucidation of membrane channels. >> Yes. So you know the cells have an inside and an outside and then they've got a border of this lipid membrane. How