YouTube: https://youtube.com/watch?v=AjfOm_W-UaY
Previous: What We Do With Dead Bodies
Next: What Happens If You Go Without Water?

Categories

Statistics

View count:641,546
Likes:11,078
Dislikes:405
Comments:1,576
Duration:05:26
Uploaded:2013-11-03
Last sync:2018-04-26 16:00
Hank describes how astronomers used a technique called gravitational lensing to find the most distant galaxy ever detected -- and how NASA is embarking on a new program to use this same technique to peer deeper into space than ever before. He also walks you through some scientific bloopers in the film "Gravity." We won't give it all away, but let's start with this: Sandra Bullock in a diaper.

-----------
Like SciShow? Want to help support us, and also get things to put on your walls, cover your torso and hold your liquids? Check out our awesome products over at DFTBA Records: http://dftba.com/artist/52/SciShow

Or help support us by subscribing to our page on Subbable: https://subbable.com/scishow
--
Looking for SciShow elsewhere on the internet?
Facebook: http://www.facebook.com/scishow
Twitter: http://www.twitter.com/scishow
Tumblr: http://scishow.tumblr.com

Thanks Tank Tumblr: http://thankstank.tumblr.com
(SciShow intro plays)

Hank Green: Welcome back to SciShow News, I'm Hank Green and I want to start this week with the tail of a year old discovery that's about to lead to even more discoveries.  Ones that may change our very understanding of the universe.  Last year, about this time, I told you about the detection by NASA scientists of what was then the most distant object in the known universe, a galaxy some 13.3 billion light years away, so distant that the light that we see from it likely dates back to 420 million years after the big bang.  In universal terms, that's like when the universe was a toddler, visible light was a new thing.  

Well, the technique we used to find that galaxy, whose name I won't even try to say out loud, proved so successful that NASA has developed a whole new program around it called frontier fields.  Astronomers detect the galaxy by training two of NASA's most powerful space-based telescopes, the Hubble and the Spitzer, on another really, really huge galaxy that was between us and the newly found one.  The gravitation of that middle galaxy is so enormous that it bends light around it, which not only allows us to see what's behind it, it also magnifies those background objects in the process.  The effect, called gravitational lensing, is a wonderful gift of the laws of physics, but it can be problematic, because it also distorts light, making it hard to tell how distant or massive the background object really is.  But by training both telescopes on the distant galaxy, the astronomers were able to factor out those distortions and measure its true size and distance.  Now, for the next three years, NASA's going to up the methodological ante by using not two, but three of the world's great orbiting telescopes, Hubble, Spitzer, and the Chandra X-Ray Observatory to create the best astronomical Swiss army knife ever.  With these tools, frontier fields will use the lensing effect of six massive galaxy clusters, magnifying background objects that would otherwise be a hundred times too faint to see.  And since light from that far away took upwards of 13 billion years to get here, some of those objects are gonna be almost as old as the universe itself.  So, frontier fields will also allow us to look back in time and see, perhaps, how the first objects in the universe formed.  Since the project launched in October, the telescopes have been trained on the first target, a huge galaxy cluster.  With the help of its gravitation, they've already discovered a super-distant supernova.  No doubt more awesome discoveries will keep coming over the next three years from frontier fields, and we will keep you posted.

And now for your consideration, some less impressive but equally fun totally fake science.  We've made fun of Hollywood's aversion to good science before, but unlike some of the other films we've talked about, there are a couple of new space movies that actually try to maintain some semblance of accuracy.  Gravity is one that works really hard to get the science right...ish.  I just saw it this weekend, it's about two astronauts, played by Sandra Bullock and George Clooney, who get marooned in open space while on a space walk gone horribly wrong.  But critics from Neil deGrasse Tyson to actual real life astronauts have been pointing out some inaccuracies that you may have noticed, I certainly did.

Tyson was quick to point out that the movie had the film's three settings: the Hubble, the ISS, and a Chinese space station, all within sight line of each other, and relatively easy to travel between.  The truth is that the Hubble orbits at about 560 km above the earth, the ISS orbits at about 400km above earth, and the Chinese station, as it's depicted, just doesn't exist, though one is in the planning stages.  Now, changing orbital planes from like, here to here in orbit, even if you're in a spacecraft, is incredibly time consuming and energy intensive, so it would be basically impossible when floating untethered in space as Clooney and Bullock are.  

Speaking of one of my favorite people in the world, Sandra Bullock, there are some problems with her crying.  I'm not passing judgement on her acting here, fantastic acting, physically though...it's just that her tears are teardrop shaped, even though liquid is spherical in a weightless environment, also due to surface tension, the tears would not leave her face as they do dramatically in the film, they would just stick to her skin, as you can see in a video that was made by Colonel Hadfield.  You should watch it, it's great.  Bullock's hair is also apparently immune to low-gravity, refusing to float free when she removes her helmet, hairspray not allowed in space.  Also, as several astronauts have noted, though she does look fantastic when she takes off her space suit and is in that really cute outfit, actually she would be wearing full body thermal underwear and an adult diaper, which would be less appealing.  But maybe this is taking place in a fictional universe when all those things are close together in orbit and in which astronauts wear cute clothes underneath their space suits.  

But the big problems are when physics just got outright violated, so just so you know, when you're in space, uh, you can peo--and it's ea--you don't have to--there's no tension.  I do want that fictional universe to have the same physics as my universe, so it does upset me when I see things that are completely not possible as major plot points in the film, which I can't even talk about because I don't want to spoil you.  But I do think you should go see it, it's an amazing movie, and you will not breathe the whole time.

Thank you for watching SciShow news, and a special super thanks to our Subbable subscribers.  Would you like to become an honorary associated producer of an episode like this, or maybe you'd like to see your name on one of our graphics or a custom message from you in our doobly-doo?  You can do all that and more, to find our how, go to Subbable.com.  And if you have any questions for us, or maybe an idea for a topic on SciShow news, you can contact us on Facebook and Twitter, and down in the comments below, and don't forget to go to YouTube.com/SciShow and subscribe.  

(SciShow Endscreen plays)