Oh my gosh XD Hank's reaction when he says 'our planet moves' lol The passion and awe of learning new things, even for someone so smart, is so fun to see ^_^
It feels good to learn something new. I have no idea why people hate being wrong so much they often delude themselves into thinking they are always right.
I love getting that awe feeling, when I suddenly understand something new, even if it's not completely new, it's new for me and it motivates me to learn more. Being proven worng in science is the time where I'll toss my pride aside and learn.
I'm surprised he didn't talk about the Doppler Effect. He talked a lot about how the universe expands and galaxies are moving away from each other. The Doppler Effect is crucial to figure out the distance between objects on the galactic scale. For those who don't know what that is: It's when something moves further away it's light waves get stretched and thus create a red shift. If that's not accounted for stars can be classified incorrectly. It also works the other way around, so when a star moves closer to us the light waves compress and make the light frequency shorter thus creating a blue shift. A good way to experience it is by hearing a cars horn as it drives towards you, and passes you. You'll notice how the sound changes depending on where the car is at any given moment.
I guess a more correct name would be redshift, it's not the exact same thing. And that's not too far from the part when they talked about Hubble, even though they dont talk about that directly.
well yes redshift/blueshift if you prefer but here i'm talking about the cosmological redshift which is not quite the same as the doppler effect, and i think that this is what can be used to determine the distance, since we know the average expansion rate of the universe, an object of such redshift would have to be at such distance, or so i would think. The point is that the cosmological redshift is very predicatable given the distance, but not for closer objects as we wouldnt see such things, we would see a redshift or blueshif it the object is moving away or closer but this is not related to the distance AFAIK. And that is when i think it can be called dopler effect, or doppler shift, depending on local velocity. Maybe that's me i could be understanding this the wrong way of course.
Nic0maK As I understand it (and I could be completely off-base), cosmological redshift--the kind that we see between galaxies--occurs not because things are moving apart from each other through space at some speed (which is how the doppler effect's redshift would be caused), but because space itself (and thus the wavelength of any light wave within that space) is expanding between the two objects. There's no real analogy to that on small scales that we're used to talking about, with the closest one possibly being the doppler effect... but as far as I understand, they're two separate processes.
Jeez, we're so smart that we can figure out how the universe works and how far away stars are but we're too stupid to figure out how to live sustainably without war or mistreating each other or [insert the list of your favorite human stupid behavior here]...something doesn't compute.
we restrain ourselves with morals and ethics. then there are these tragedy of the commons-problems. only one atmosphere, and when one tiny nation pollutes it A LOT and gains economic growth from it, they just wont stop. some problems could be solved, if it would be acceptable to bomb coal mines and coal power plants around the world simply because they are in operation, and to put snipers in the few primary forests we have left that just put a bullet into anyone who carries a chainsaw, causes a fire, or does illegal logging. when people drill holes into rhino horns and fill them with a poison that causes extreme vomiting and diarrhoe (not even death), trying to save the rhinos from the stupidity of chinese medicine, thats already controversial. and when someone from sea shepherd attached magnetic mines to some whaling ships in port to sink them (noone got hurt, they sank slowly and peacefully in port), thats going too far.
iamihop Oh, I understand perfectly WHY we're douchebags. I just hate THAT we are XD . I've given it much thought over the years, and the only way for true peace to evolve would be for it to suddenly occur in almost everyone simultaneously. Which...well, let's just say is far too improbable to think it'll ever happen. Unless there's a disease that kills off all the assholes :P
I think it's important to draw a distinction between knowledge/understanding and morality/ethics. Science is designed to poke the universe and figure out how it works, what is around us, inside of us, what we're made of and why things happen. War, greed, violence and other unpleasant human behaviors are in the realm of ethics, which isn't really something science is designed to deal with (e.g. from a purely objective perspective it is sensible to kill one healthy individual and harvest the organs in order to save the lives of five other individuals, assuming they are all equal and perfect matches, but of course almost everyone will agree this is completely immoral and wrong). Another factor that may contribute to detrimental human activities is a variation of the prisoner's dilemma: in an ideal society we would all be selfless and be more than willing to share and give anything we have to anyone who needs it. Everyone would benefit. But it only takes one person to take advantage of the situation, or 'betray' society, by taking but never giving. Then that one person has a greater benefit than the rest, which in turn makes it less convenient for others to give freely: now there's a risk that if they give, the action may not be reciprocated. More mistrust is generated and even more people choose to be greedy, being willing to obtain but reluctant to give.
What's the furthest star that we know of? It's definitely over 12,000 ly away right? How can ppl think the earth is only 6-12000 years old? (By ppl I mean the religious)
Well the farthest away thing we can detect is the cosmic microwave background, wich the light coming from it is so old that there were no stars back when that light was emited. The farthest away galaxy that we can detect was formed 420 million years after the big bang so the light from that galaxy has been traveling for about 13 billion years. The only stars that we can see from this super far away galaxies is when there is a supernova. Creationist (or at least some) claim that the speed of light has not been consistent and thats why objects seem more farther away than what they really are.
We discovered an early forming galaxy at over 13.2 billion light years away when the Universe was still developing into the form we see today.'' Oh, I see it was already answered :)
z8_GND_5296 is a galaxy discovered in October 2013. It was approximately 13.1 gigalight-years from Earth when the light that is reaching us now was emitted (it's farther away than that now, because the universe is expanding). That is 4.0 x 10^9 parsecs. 1.23427103 × 10^23 kilometers. It was forming stars at an incredible rate, about 300 stars a year, a mere 700 million years after the Big Bang.
They either think that all scientists (and that's not even only astronomers of course but also geologists, paleontologists, archaeologists and biologists) got it all wrong by seven orders of magnitude or so, or that God tried to fool us. Yeah, I don't know which of these two explanations I find more mind-boggling either.
2:39, the instant Hank realizes the answer himself without being explicitly told - this is why science and learning are awesome. And though I'm not a teacher, I think I understand why this is the sort of moment that teachers live for.
OMG! I've been bugging SciShow with this question for like a whole month!! I'd like to think that they made this entire episode on my behalf. You're welcome TH-cam.
Loved getting to see Hanks mind blown. I've had that same reaction to so many videos on this channel, as well as on Crash Course. Thanks so much for constantly teaching me something new!
So, you might have heard of the unit of distance called a parsec. It's about 3.26 light years, which is not exactly a round number. So how did we come up with that unit? Well, it's based on the apparent motion of the stars described in this video. We do the trigonometry Phil mentioned, and in doing so determine the angle of the parallax, i.e. the angle you'd get at the astronomical object if you drew a right triangle with one vertex at the Earth, one at the Sun (i.e. the short leg of the triangle is 1 AU), and the third at the distant object. When that angle is equal to 1 arcsecond, we give the distance to that object a name: a PARallax arcSECond, or parsec.
Love how you can just see Hanks mind being blown sentence by sentence, and then how he struggles to ask something afterwards, because his mind has been so thoroughly blow.
Hank was continually amazed by not only what we discovered but how we discovered it. That is why space has remained my favorite thing to learn about for over 20 years. Thanks ***** for starting a whole course on CC.
This was on my reading material for my physics exam earlier this year, and it still amazes me how we can get so much information just by observing the light of billions of tiny dots in the sky, I hadn't realized how recent this all was, we haven't know about other galaxies for very long at all!
Well your seasons are opposite. It wouldn't make sense to have summer break from June-August like we do, because that would be winter in Australia. It makes sense that your school is shifted by a few months, to account for the shifted weather patterns. Which bring up the question: do you even have winter in Australia? Or is it just hot all the time? Because that would kinda make my point moot...
Ben Aguilar Today in Melbourne it rained so hard that I started to believe someone had opened a portal connecting the bottom of the ocean to the sky. Yesterday it was pleasant and sunny.
0:25 'Five US dollars will pay for a child in Zambia to school for two months and have a meal there every day.' HOW?! How is just five dollars _anywhere_ near enough to do that?
If you give five dollars to that charity, they use the collected money and all the other contributions they get to finance their program. Your five dollars are nlt the only thing that pay for it, but you feel better if you think it is that way.
www.wolframalpha.com/input/?i=poverty+zambia If 75% of the population is below $1.25/day, it's safe to assume there is some large percentage living on much less. Like $15/mo for a family. In which case a third of that is going to a single child (if they were attending school and eating enough).
I had the exact same expressions as Hank. This format is awesome, someone very knowledgeable talking about a subject the host does not know, but wants to know about. Then just let the questions roll and don't do jump cuts. Thank you
I don't see how people can still say with such certainty that we are the only planet with intelligent life on it. The statistical probability of that being true, even with the numbers of just galaxies, has got to be trillions to one at least.
This was one instance where I was surprised that he was mindblown. I took trigonometry in high school and was able to discern the trigonometric parallax way back then. The Sine/Cosine laws are very handy.
jg martn No, he wasn't amazed by the idea of parallax. He just hadn't thought about how the movement of Earth allowed us multiple vantage points from which to view stars, so when Phil mentioned that, it was one of those, "OH! RIGHT! I can't believe I didn't think of that!" moments :)
IceMetalPunk You need multiple vantage points (at least two) in order to compute trigonometric parallax. It's simply a fundamental requirement. There is nothing mind-boggling about this. 0.o
jg martn Yes, obviously, but he just didn't think about how the motion of the Earth ALLOWS for multiple vantage points from the same planet. It's just one of those things where the pieces are there, but the connection wasn't made until this video :)
+momori momo Well, you kind of don't, from what I understand. We only have light to tell us the whereabouts of something in the universe and light travels at a relatively slow speed, in comparison with the size of the universe. So when we measure something, we are measuring the distance the object was at the time the light our eye's are seeing gets to us. Since that light left the object it has moved and the universe has expanded (to include our solar system). You can, however, know the rate of expansion and add it into the equation, I suppose.
+momori momo We can measure motion of stars (called their proper motion) using red-shift. Z = (λobs - λemitted)/λemitted ≈ v||/c where Z is the red shift. λobs is the wavelength we observe. λemitted is the wavelength emitted (we have to measure the star's spectrum to determine what this must be, it's somewhat involved but pretty coll). v|| is the velocity of the star in the direction parallel to us. c is the speed of light. So we can use this technique to determine how fast the star is moving away or towards us. You can apply this technique to galaxies as well. Hope that made sense.
We learn fast but we still have a long way to go... That's why real education is paramount & science should be at the heart of it all. Loved your reaction Hank! Isn't it wonderful to learn something new every day?
Oh and we're not insignificant, any form of life is more complex than anything in this entire Universe (From what life knows). A single cell is more complex than anything, a brain has more neurons than a galaxy has stars. Life - not just humans, or earthlings, but life - is the most significant thing about this universe so far, everything else is just billiard ball mechanic matter.
The average galaxy contains many times more neurons than the human brain does. It would have to be a relatively small galaxy to be close. Some of the larger galaxies contain upward of a trillion stars. However the human brain is one of the most complex objects humans have ever observed. The quantum world is also quite the interesting place too.
GreatOak99 You seem to not understand that there's no difference between theory and fact. If we have no theory for something, we have yet to explain that thing. If data contradicts a theory, the theory is discarded. Theories are only well-substantiated explanations of data we have. What you're saying is like saying we are only guesstimating that the Earth has gravity or the Sun has gravity when in fact we have gathered data and figured out that they have gravity.
Kai Simon if they had no difference we wouldn't have two words. and im sure you can prove gravity exists, but proving a planet is that far without experiencing its distance is another matter
The last time I checked, there was no consensus on this but there are two prevailing theories. Basically, the big rip, wherein the universe just keeps expanding and all the planets and stars rip apart and atoms scatter until the universe is essentially empty. That or the big crunch, where at some point the universe acts as an elastic, begins to resist the spreading and then eventually pulls everything back in to where we started before the big bang.
it comes in for distant galaxies only, it's not something we could observe on a smaller scale i think, it has to do with how fast things are moving closer/away from you. i guess since we have an idea of the average rate of expansion, and because it's rather uniform in every direction we look, knowing how fast a galaxy is moving away from you by mesuring its red shift could in turn help determine its distance.
You were correct. As David said, red-shifting is used to indicate how quickly a distant object is moving away from us. Once we know how fast it's moving away from us (due to the expansion of the universe) we know how much space is between us.
DonTHEhandsome1 Neil deGrasse Tyson, on being asked “What is the most astounding fact you can share with us about the Universe?” - “When I look up at the night sky, and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than both of those facts is that the Universe is in us. When I reflect on that fact, I look up - many people feel small, ’cause they’re small and the Universe is big, but I feel big, because my atoms came from those stars.”
Why is he "Bad Astronomer Phil"? While I had an idea of how they measured the distance to stars, Phil by far gave the clearest explanation I've ever heard. I feel like I really understand it now.
I loved this video personally because I learned something and so did hank. Majority of the time it's just us learning. I consider hank an extremely smart person and to see him learning something new and just being in awe like he was, was neat to see. He truly has a love and appreciation of learning.
Not everybody is like you. American currency in other countries can be worth a fortune. 100 dollars seems trivial to a millionaire. 1 dollar seems trivial to the average american. 1 dollar can mean life or death for some people, especially if they happen to live in 3 world countries.
PitchBlackFox Also, many companies and governments will offer to "match" the donations made by other people or groups. If you get enough groups doing that, your US$5 might turn into a US$20+ by the time it actually hits the ground in Africa.
Great technique to ask how do we measure close up.....then to trigalax that to standard candles.....this really helped me get my head around Hubble's ecstasy.
Why racism? I dont care they are black, white or blue. There thousands of people are dying without food and water but you want to spend money make bush people read..
Religion isn't about intelligence, it's about our human nature to desire something greater than our earthly existence. A lot of people like the idea that when they die they move on to a better existence rather than just becoming a rotting corpse.
Explain to me how the universe cease out of nowhere ... And also explain to me how our earth is literally perfect in every way to support life. Perfect heat to hold water and IT HAS ITS OWN ATMOSPHERE! Also the perfect size for gravity to keep the world from flooding ... Sci show did an episode on how perfect our world actually is set up ... Ya.
TheWildOnesAreBack well if it wouldn't be perfect there wouldn't be life and if there wouldn't be life there wouldn't us asking this questions. Also perfect for us might also mean that it literally shaped us to find it perfect. An alien lifeform might consider his world, which can be totally hostile to us, to be perfect.
It is wonderful to see you in awe of the information you are learning about in the moment. You are the one usually enlightening us so much. This is one of my favorite episodes of SciShow, thanks for doing a little extra for "School of TH-cam week!
I love this so much. I am taking my first astronomy class in college this semester, and everything I am learning is mind blowing every day. I am glad I am not the only one finding this mind blowing! Astronomy is awesome.
Love the aha! moment at 2:35 and that moment of deep appreciation of human ingenuity at 7:00...something I always enjoy watching my students do when I share real-life applications of maths and science!
The moment Hank got the parallax trick for measuring distances to nearby stars was priceless. This is why I've volunteered as a telescope operator at the Chabot Space & Science Center in Oakland, CA for over 20 years. We witness these "moments of enlightenment" in the public all the time; it's sustaining, gratifying, addictive and just plain FUN. If you have the time, I highly recommend volunteering at some institute of public science education, yourselves. You not only help others learn, YOU learn, too, and an educated society is a sane society.
I was *just* contemplating this after watching several SciShow Space videos. I'm so glad I stumbled on this video! It all makes so much more sense! Thanks, SciShow!
Parallax is only for closer stars. For distant stars we use Spectroscopy to measure various forms of radiation activity from a star. This way we can determine the type of star, condition and associate the star to one of the known star type from Stellar Classification. Once we know the star type and condition, we determine the 'true' luminosity in the proximity of the star. Then we compare this luminosity to the star's luminosity perceived here on Earth. The difference of the two luminosities is then converted in distance (the further away an object is located, the dimmer the light). We can also determine the distance to far away galaxies when we receive the light from a Supernova located inside such galaxy. We know how bright a Supernova is (much brighter even than the entire galaxy), and estimate the distance to the Supernova and to the Galaxy
I found the info in this video interesting in and of itself, but my greatest pleasure in watching it came from Hank getting his mind blown. His enthusiasm is contagious even through the screen. x)
I really like this kind of video! the back and forth conversation I think is really good, and I might even like it more than just Hank talking at me. This was a great video!
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Thank you so much, Hank, for these videos!! Also, it is very endearing to see how excited you are while listening to scientific explanations. I can see the joy of learning in your face. So keep it up! You're doing an awesome job!
8:27 I heard someone comment on this before and they said that when Hubble discovered that the Andromeda Galaxy is an entirely different galaxy to our own, our understanding of the size of the universe had doubled overnight. Mind. Blown.
Since the universe is expanding that means we cannot safely say 10 years from now that the distance of a cosmic object we measured now will have the same value then. To me, that is mindblowing
I'd love to see a TH-cam channel with this kind of content-not just *what* we know thanks to Science, but *how* we know it.
Oh my gosh XD Hank's reaction when he says 'our planet moves' lol The passion and awe of learning new things, even for someone so smart, is so fun to see ^_^
It feels good to learn something new. I have no idea why people hate being wrong so much they often delude themselves into thinking they are always right.
Signed in to say just this. The spark in his eyes when he pieces it together for himself is the same reason I get up in the morning.
I love getting that awe feeling, when I suddenly understand something new, even if it's not completely new, it's new for me and it motivates me to learn more.
Being proven worng in science is the time where I'll toss my pride aside and learn.
FlyingJetpack1 I hear ya buddy!
I agree with this conversation so much :)
Hank was so mind blow I love it
watch pbs space time, much better
The childlike wonder in Hank's voice made me tear up a bit.
Hanks Definitely man crushing on the bad astronomer.
and he asked him out for a drink. XD
I am so jealous how brilliant some people are! I feel like i am wasting my life just working and not discovering. Great conversation guys
Knowing isn't brilliance. If you study something eventually you'd know fancy terms and sound 'brilliant', too.
@@mickobrien3156 They chose to pursue knowledge in that field, we didn't, everyone can be brilliant in their own fields if they are willing to learn
Did Hank just man-crush?
I'm pretty sure he man-crushed on the universe just there.
Totally man-crushed.
What man-crush means?
That he flirt with the guy? I hope not! lol
JGuilherme He got a theoretical boner for the guy. Now that the theory has been established, time for some "experimentation."
He had an ah-ha moment that was total fun to watch. Hank rocks!!! at 2:40 "But our planet moves" - the lightbulb goes on immediately.
I'm surprised he didn't talk about the Doppler Effect. He talked a lot about how the universe expands and galaxies are moving away from each other. The Doppler Effect is crucial to figure out the distance between objects on the galactic scale.
For those who don't know what that is: It's when something moves further away it's light waves get stretched and thus create a red shift. If that's not accounted for stars can be classified incorrectly. It also works the other way around, so when a star moves closer to us the light waves compress and make the light frequency shorter thus creating a blue shift.
A good way to experience it is by hearing a cars horn as it drives towards you, and passes you. You'll notice how the sound changes depending on where the car is at any given moment.
I guess a more correct name would be redshift, it's not the exact same thing. And that's not too far from the part when they talked about Hubble, even though they dont talk about that directly.
Nic0maK No. Redshift only applies to things moving away from us. Doppler effect is correct.
NerdNordic Stars moving towards us (shifting towards blue) are still described using the term 'red shift'.
well yes redshift/blueshift if you prefer but here i'm talking about the cosmological redshift which is not quite the same as the doppler effect, and i think that this is what can be used to determine the distance, since we know the average expansion rate of the universe, an object of such redshift would have to be at such distance, or so i would think.
The point is that the cosmological redshift is very predicatable given the distance, but not for closer objects as we wouldnt see such things, we would see a redshift or blueshif it the object is moving away or closer but this is not related to the distance AFAIK. And that is when i think it can be called dopler effect, or doppler shift, depending on local velocity.
Maybe that's me i could be understanding this the wrong way of course.
Nic0maK As I understand it (and I could be completely off-base), cosmological redshift--the kind that we see between galaxies--occurs not because things are moving apart from each other through space at some speed (which is how the doppler effect's redshift would be caused), but because space itself (and thus the wavelength of any light wave within that space) is expanding between the two objects. There's no real analogy to that on small scales that we're used to talking about, with the closest one possibly being the doppler effect... but as far as I understand, they're two separate processes.
Nice to see Hank as a student for a change, and to see how he loves to learn.
Jeez, we're so smart that we can figure out how the universe works and how far away stars are but we're too stupid to figure out how to live sustainably without war or mistreating each other or [insert the list of your favorite human stupid behavior here]...something doesn't compute.
we restrain ourselves with morals and ethics. then there are these tragedy of the commons-problems. only one atmosphere, and when one tiny nation pollutes it A LOT and gains economic growth from it, they just wont stop.
some problems could be solved, if it would be acceptable to bomb coal mines and coal power plants around the world simply because they are in operation, and to put snipers in the few primary forests we have left that just put a bullet into anyone who carries a chainsaw, causes a fire, or does illegal logging.
when people drill holes into rhino horns and fill them with a poison that causes extreme vomiting and diarrhoe (not even death), trying to save the rhinos from the stupidity of chinese medicine, thats already controversial. and when someone from sea shepherd attached magnetic mines to some whaling ships in port to sink them (noone got hurt, they sank slowly and peacefully in port), thats going too far.
The duality of man.
You can never forget that for every horrible thing you see on the news an amazing thing happened that is almost never reported.
We're smart, but we're not as empathetic as we could be.
iamihop
Oh, I understand perfectly WHY we're douchebags. I just hate THAT we are XD . I've given it much thought over the years, and the only way for true peace to evolve would be for it to suddenly occur in almost everyone simultaneously. Which...well, let's just say is far too improbable to think it'll ever happen. Unless there's a disease that kills off all the assholes :P
I think it's important to draw a distinction between knowledge/understanding and morality/ethics. Science is designed to poke the universe and figure out how it works, what is around us, inside of us, what we're made of and why things happen. War, greed, violence and other unpleasant human behaviors are in the realm of ethics, which isn't really something science is designed to deal with (e.g. from a purely objective perspective it is sensible to kill one healthy individual and harvest the organs in order to save the lives of five other individuals, assuming they are all equal and perfect matches, but of course almost everyone will agree this is completely immoral and wrong).
Another factor that may contribute to detrimental human activities is a variation of the prisoner's dilemma: in an ideal society we would all be selfless and be more than willing to share and give anything we have to anyone who needs it. Everyone would benefit. But it only takes one person to take advantage of the situation, or 'betray' society, by taking but never giving. Then that one person has a greater benefit than the rest, which in turn makes it less convenient for others to give freely: now there's a risk that if they give, the action may not be reciprocated. More mistrust is generated and even more people choose to be greedy, being willing to obtain but reluctant to give.
What's the furthest star that we know of? It's definitely over 12,000 ly away right? How can ppl think the earth is only 6-12000 years old? (By ppl I mean the religious)
Well the farthest away thing we can detect is the cosmic microwave background, wich the light coming from it is so old that there were no stars back when that light was emited. The farthest away galaxy that we can detect was formed 420 million years after the big bang so the light from that galaxy has been traveling for about 13 billion years. The only stars that we can see from this super far away galaxies is when there is a supernova.
Creationist (or at least some) claim that the speed of light has not been consistent and thats why objects seem more farther away than what they really are.
***** Thank you sir. I will smoke a bowl to the 420. :) *High 5*
We discovered an early forming galaxy at over 13.2 billion light years away when the Universe was still developing into the form we see today.''
Oh, I see it was already answered :)
z8_GND_5296 is a galaxy discovered in October 2013. It was approximately 13.1 gigalight-years from Earth when the light that is reaching us now was emitted (it's farther away than that now, because the universe is expanding). That is 4.0 x 10^9 parsecs. 1.23427103 × 10^23 kilometers. It was forming stars at an incredible rate, about 300 stars a year, a mere 700 million years after the Big Bang.
They either think that all scientists (and that's not even only astronomers of course but also geologists, paleontologists, archaeologists and biologists) got it all wrong by seven orders of magnitude or so, or that God tried to fool us. Yeah, I don't know which of these two explanations I find more mind-boggling either.
2:39, the instant Hank realizes the answer himself without being explicitly told - this is why science and learning are awesome. And though I'm not a teacher, I think I understand why this is the sort of moment that teachers live for.
OMG! I've been bugging SciShow with this question for like a whole month!! I'd like to think that they made this entire episode on my behalf.
You're welcome TH-cam.
Hanks reaction, when Phil says "Ah but our planet moves!" was amazing. That was the ned and want to learn even if you are smart...Cool right?
Loved getting to see Hanks mind blown. I've had that same reaction to so many videos on this channel, as well as on Crash Course. Thanks so much for constantly teaching me something new!
i love love love how Hank was so amazed by everything Phil said, and his enthusiasm and interest was just so cute ahhhh
Hank looks so mindblown XD
So, you might have heard of the unit of distance called a parsec. It's about 3.26 light years, which is not exactly a round number. So how did we come up with that unit? Well, it's based on the apparent motion of the stars described in this video. We do the trigonometry Phil mentioned, and in doing so determine the angle of the parallax, i.e. the angle you'd get at the astronomical object if you drew a right triangle with one vertex at the Earth, one at the Sun (i.e. the short leg of the triangle is 1 AU), and the third at the distant object. When that angle is equal to 1 arcsecond, we give the distance to that object a name: a PARallax arcSECond, or parsec.
At 2:39 if you look really close, you can see the exact moment that Hank's mind explodes
Love how you can just see Hanks mind being blown sentence by sentence, and then how he struggles to ask something afterwards, because his mind has been so thoroughly blow.
lol I love Hank's "Why didn't I think of that?!" moment XD
Hank was continually amazed by not only what we discovered but how we discovered it. That is why space has remained my favorite thing to learn about for over 20 years. Thanks ***** for starting a whole course on CC.
Hanks reaction is priceless.
This was on my reading material for my physics exam earlier this year, and it still amazes me how we can get so much information just by observing the light of billions of tiny dots in the sky, I hadn't realized how recent this all was, we haven't know about other galaxies for very long at all!
so in this apparently "insane" country of Australia, we start the school year AT THE START OF THE YEAR!! WHY IS THAT WEIRD TO PEOPLE?!
It really depends on the school, it seems, since I recall some schools doing the same thing in my country.
Well your seasons are opposite. It wouldn't make sense to have summer break from June-August like we do, because that would be winter in Australia. It makes sense that your school is shifted by a few months, to account for the shifted weather patterns.
Which bring up the question: do you even have winter in Australia? Or is it just hot all the time? Because that would kinda make my point moot...
contrary to popular belief, it gets freezing here. We are pretty much as close to Antarctica as you can get without going white on a map
Both extremes
Ben Aguilar Today in Melbourne it rained so hard that I started to believe someone had opened a portal connecting the bottom of the ocean to the sky. Yesterday it was pleasant and sunny.
This was easily one of my favorite SciShows so far
this was an extremely awesome conversation.
Hank's voice and demeanor at 1:15 is so gentle and unassuming, I don't know why it changed like that but it's so sweet
0:25 'Five US dollars will pay for a child in Zambia to school for two months and have a meal there every day.'
HOW?! How is just five dollars _anywhere_ near enough to do that?
If you give five dollars to that charity, they use the collected money and all the other contributions they get to finance their program. Your five dollars are nlt the only thing that pay for it, but you feel better if you think it is that way.
That's just misleading.
Yes, but it does raise more many for charity than simply saying:
Give us money, so we can help.
Basically $5 is a lot is some country's 30 years ago $5 could get you a decent car out in Africa
www.wolframalpha.com/input/?i=poverty+zambia
If 75% of the population is below $1.25/day, it's safe to assume there is some large percentage living on much less. Like $15/mo for a family. In which case a third of that is going to a single child (if they were attending school and eating enough).
'I hadn't even thought about how we would measure how far away a galaxy is'. The wonderment in his voice, Hank is such a sweetie.
This just blew my mind.
It also blew Hanks :)
I had the exact same expressions as Hank. This format is awesome, someone very knowledgeable talking about a subject the host does not know, but wants to know about. Then just let the questions roll and don't do jump cuts. Thank you
Watching Hank realize what we've done with science is just fantastic.
Phil looks so cute talking about astronomy! You can hear the passion he feels when he teaches it in his voice! :D
I don't see how people can still say with such certainty that we are the only planet with intelligent life on it. The statistical probability of that being true, even with the numbers of just galaxies, has got to be trillions to one at least.
Easily my favorite SciShow Space video yet. I knew some of this, but what I didn't know, I'm really glad I know now.
wow... Seeing Hank's brain explode was awesome.
@ 2:39 Hank's moment of realization is priceless. That is the greatest thing about science; moments like that.
Hank's ability to even became severely compromised around 6:40.
Hank's pure amazement is so great to watch...
It's not often hank's mind is blow but it's always entertaining when it is.
This was one instance where I was surprised that he was mindblown. I took trigonometry in high school and was able to discern the trigonometric parallax way back then. The Sine/Cosine laws are very handy.
I think it might have been the fact that we have things that can measure such small movement that blew his mind.
jg martn
No, he wasn't amazed by the idea of parallax. He just hadn't thought about how the movement of Earth allowed us multiple vantage points from which to view stars, so when Phil mentioned that, it was one of those, "OH! RIGHT! I can't believe I didn't think of that!" moments :)
IceMetalPunk You need multiple vantage points (at least two) in order to compute trigonometric parallax. It's simply a fundamental requirement. There is nothing mind-boggling about this. 0.o
jg martn
Yes, obviously, but he just didn't think about how the motion of the Earth ALLOWS for multiple vantage points from the same planet. It's just one of those things where the pieces are there, but the connection wasn't made until this video :)
Seeing Hank bewildered is really fun for me. It reminds me that he is just human like the rest of us.
How do we account for the movement of our solar system when we're measure the distance of stars?
+momori momo Well, you kind of don't, from what I understand. We only have light to tell us the whereabouts of something in the universe and light travels at a relatively slow speed, in comparison with the size of the universe. So when we measure something, we are measuring the distance the object was at the time the light our eye's are seeing gets to us. Since that light left the object it has moved and the universe has expanded (to include our solar system). You can, however, know the rate of expansion and add it into the equation, I suppose.
+ABDULAZIZ ALAHMADI more like 300,000 times further!
Those stars are moving with us just like we are.
+momori momo
We can measure motion of stars (called their proper motion) using red-shift.
Z = (λobs - λemitted)/λemitted ≈ v||/c
where Z is the red shift.
λobs is the wavelength we observe.
λemitted is the wavelength emitted (we have to measure the star's spectrum to determine what this must be, it's somewhat involved but pretty coll).
v|| is the velocity of the star in the direction parallel to us.
c is the speed of light.
So we can use this technique to determine how fast the star is moving away or towards us. You can apply this technique to galaxies as well.
Hope that made sense.
***** plus the movement of some stars cancel out the movement of our solar system has some of them move along the same path as we do.
Phil Plait's presence is the antidote to my occasional misanthropy. Phil and Hank, of course.
100% free education and healthcare where i live
You pay for that education and healthcare with your taxes.
same here !
Awesome. Where do you live?
Norway, Sweden, Denmark and German has a good amount of free things.
Yair Gutierrez norway
We learn fast but we still have a long way to go... That's why real education is paramount & science should be at the heart of it all.
Loved your reaction Hank! Isn't it wonderful to learn something new every day?
Oh and we're not insignificant, any form of life is more complex than anything in this entire Universe (From what life knows). A single cell is more complex than anything, a brain has more neurons than a galaxy has stars. Life - not just humans, or earthlings, but life - is the most significant thing about this universe so far, everything else is just billiard ball mechanic matter.
I mean...life is just like all other matter, though...
The average galaxy contains many times more neurons than the human brain does. It would have to be a relatively small galaxy to be close. Some of the larger galaxies contain upward of a trillion stars. However the human brain is one of the most complex objects humans have ever observed. The quantum world is also quite the interesting place too.
jojo300001
jojo300001
***** Not really
Watching Hank's mind get blown is such a rewarding experience as a viewer. NO EDGE!
I wonder what degree of accuracy these measurements are?
From the scale of loose to pinpoint it's at a guesstimate and is still theorized and not proven fact.
GreatOak99 You seem to not understand that there's no difference between theory and fact. If we have no theory for something, we have yet to explain that thing. If data contradicts a theory, the theory is discarded. Theories are only well-substantiated explanations of data we have. What you're saying is like saying we are only guesstimating that the Earth has gravity or the Sun has gravity when in fact we have gathered data and figured out that they have gravity.
Sometimes the margin of error is as low as plus or minus 1%.
GreatOak99 --Parallax is a testable proven way of measuring distances. So quick talking out of your ass.
Kai Simon if they had no difference we wouldn't have two words. and im sure you can prove gravity exists, but proving a planet is that far without experiencing its distance is another matter
love how fascinated and excited hank is during the explanation :33
If the universe is always expanding then what does it expand into?
Existence is expanding into eternal non-existance...
The last time I checked, there was no consensus on this but there are two prevailing theories. Basically, the big rip, wherein the universe just keeps expanding and all the planets and stars rip apart and atoms scatter until the universe is essentially empty. That or the big crunch, where at some point the universe acts as an elastic, begins to resist the spreading and then eventually pulls everything back in to where we started before the big bang.
***** haven't heard of that one. I'll have to look into it.
I love seeing Hank's awe at trying to understand the universe! I get that way too.
Where does the red shift of an object come in to play? I thought it had to do with measuring distance, but I guess I was wrong (again).
it comes in for distant galaxies only, it's not something we could observe on a smaller scale i think, it has to do with how fast things are moving closer/away from you. i guess since we have an idea of the average rate of expansion, and because it's rather uniform in every direction we look, knowing how fast a galaxy is moving away from you by mesuring its red shift could in turn help determine its distance.
It has to do with how quick the object is moving away from us.
Nic0maK David Markus
Thanx. 😁
You were correct. As David said, red-shifting is used to indicate how quickly a distant object is moving away from us. Once we know how fast it's moving away from us (due to the expansion of the universe) we know how much space is between us.
Ryan Harding
Yeah, that's why I was surprised when it didn't come up in the discussion. Thanx. 😊
Phil has always been a good science communicator.
His blog is well worth reading.
you use the Distance formula, duh!
...
Close enough.
fossilfighters101 haha I tried.
Brandon Jin ahh gotcha.
***** you mean 3D distance formula?
I started crying this information was so beautiful to listen to. This video was perfection.
Now don't we all feel small and insignificant when it comes to everything in the universe.
But we also know that we're part of it, atom for atom
DonTHEhandsome1 Neil deGrasse Tyson, on being asked “What is the most astounding fact you can share with us about the Universe?” - “When I look up at the night sky, and I know that, yes, we are part of this Universe, we are in this Universe, but perhaps more important than both of those facts is that the Universe is in us. When I reflect on that fact, I look up - many people feel small, ’cause they’re small and the Universe is big, but I feel big, because my atoms came from those stars.”
I can't even deal. I just can't.
no i dont, i feel even more special for being a part of it
I see it the other way. Out of all these thing we found, we are the only place that has created such diverse and intelligent life.
Why is he "Bad Astronomer Phil"? While I had an idea of how they measured the distance to stars, Phil by far gave the clearest explanation I've ever heard. I feel like I really understand it now.
OMG! WHY THE HELL COULDN'T YOU FILM YOUR DRINKIN-ASTRO TALK!!!!! GODDAMNN ITT!
90MILLION VIEWS RIGHT THERE!
watch pbs space time, much beter
I loved this video personally because I learned something and so did hank. Majority of the time it's just us learning. I consider hank an extremely smart person and to see him learning something new and just being in awe like he was, was neat to see. He truly has a love and appreciation of learning.
how does 5 dollars equal 2 months of school and meals? my lunch 2.25 a day
How much of the local currency are 5 dollars? Several thousand.
Not everybody is like you. American currency in other countries can be worth a fortune. 100 dollars seems trivial to a millionaire. 1 dollar seems trivial to the average american. 1 dollar can mean life or death for some people, especially if they happen to live in 3 world countries.
also money is pooled together and the charities buy in bulk and probably get some discounts from companies, all reducing the cost for one child
5 dollars translates into a lot of money in some countries because of the state of their economy.
PitchBlackFox Also, many companies and governments will offer to "match" the donations made by other people or groups. If you get enough groups doing that, your US$5 might turn into a US$20+ by the time it actually hits the ground in Africa.
Great technique to ask how do we measure close up.....then to trigalax that to standard candles.....this really helped me get my head around Hubble's ecstasy.
Learn what? How to hunt Elephants?
Wow, racism
More than you learn most likely mr.high school drop out
Why racism? I dont care they are black, white or blue. There thousands of people are dying without food and water but you want to spend money make bush people read..
Disciple Demon
The stupidity flows strong through you.
Disciple Demon
So they can't afford an education so you think they shouldn't get schooled because of their lack of education? What the fuck, man.
The whole time I'm watching this I'm thinking about Hank and his reverie that the universe has no edge. I couldn't stop smiling.
We are smart enough to measure the distance of stars but still dumb enough to have most of the population beleive in some almighty deity? Wtf
Religion isn't about intelligence, it's about our human nature to desire something greater than our earthly existence. A lot of people like the idea that when they die they move on to a better existence rather than just becoming a rotting corpse.
Explain to me how the universe cease out of nowhere ... And also explain to me how our earth is literally perfect in every way to support life. Perfect heat to hold water and IT HAS ITS OWN ATMOSPHERE! Also the perfect size for gravity to keep the world from flooding ... Sci show did an episode on how perfect our world actually is set up ... Ya.
TheWildOnesAreBack well if it wouldn't be perfect there wouldn't be life and if there wouldn't be life there wouldn't us asking this questions. Also perfect for us might also mean that it literally shaped us to find it perfect. An alien lifeform might consider his world, which can be totally hostile to us, to be perfect.
Comes more from the fear of death imo.
TheWildOnesAreBack
Once science finds the many other planets out there that are also "perfect" for life, this thought process will be gone, hopefully.
It is wonderful to see you in awe of the information you are learning about in the moment. You are the one usually enlightening us so much. This is one of my favorite episodes of SciShow, thanks for doing a little extra for "School of TH-cam week!
I love this so much. I am taking my first astronomy class in college this semester, and everything I am learning is mind blowing every day. I am glad I am not the only one finding this mind blowing! Astronomy is awesome.
I have a semester of learning just THIS. Man I am so pumped for the next couple of months
Hank's epiphany was really fun to watch.
Love the aha! moment at 2:35 and that moment of deep appreciation of human ingenuity at 7:00...something I always enjoy watching my students do when I share real-life applications of maths and science!
This Phil guy is talking/acting like a kid in a candy store, must love his job!!!
Hank's enthusiasm is the best. Also, can Phil become a frequent host? Please? He's awesome.
The moment Hank got the parallax trick for measuring distances to nearby stars was priceless. This is why I've volunteered as a telescope operator at the Chabot Space & Science Center in Oakland, CA for over 20 years. We witness these "moments of enlightenment" in the public all the time; it's sustaining, gratifying, addictive and just plain FUN. If you have the time, I highly recommend volunteering at some institute of public science education, yourselves. You not only help others learn, YOU learn, too, and an educated society is a sane society.
I was *just* contemplating this after watching several SciShow Space videos. I'm so glad I stumbled on this video! It all makes so much more sense! Thanks, SciShow!
Parallax is only for closer stars. For distant stars we use Spectroscopy to measure various forms of radiation activity from a star. This way we can determine the type of star, condition and associate the star to one of the known star type from Stellar Classification. Once we know the star type and condition, we determine the 'true' luminosity in the proximity of the star. Then we compare this luminosity to the star's luminosity perceived here on Earth. The difference of the two luminosities is then converted in distance (the further away an object is located, the dimmer the light). We can also determine the distance to far away galaxies when we receive the light from a Supernova located inside such galaxy. We know how bright a Supernova is (much brighter even than the entire galaxy), and estimate the distance to the Supernova and to the Galaxy
It was a genuine pleasure to watch Hank's mind get blown in this episode. More mind-blowing astronomy bordering on philosophy, please.
Strangely this is the first video in the School of TH-cam theme I've seen that actually provided proper info about the charity and where to donate.
It's the first time I see Hank so amazed and mind boggled. :D
I like how Phil Plait explains things. He's not quite as boisterous as NDT but he seems like a pretty laid back dude that would be cool to chill with.
This is great! You can see the look of awesomeness on hanks face!
Phil is awesome!!! Hank is so lucky to hang out with him.
I found the info in this video interesting in and of itself, but my greatest pleasure in watching it came from Hank getting his mind blown. His enthusiasm is contagious even through the screen. x)
Dude this is pure genius. And the best part about it is that its not even that hard to understand.
I would love to see more videos like this, with people actually discussing the topic instead of just a lecture.
I really like this kind of video! the back and forth conversation I think is really good, and I might even like it more than just Hank talking at me. This was a great video!
Thank you so much, Hank, for these videos!!
Also, it is very endearing to see how excited you are while listening to scientific explanations. I can see the joy of learning in your face. So keep it up! You're doing an awesome job!
Hanks reaction at 2:48 is awesome. LEARNING!
I love how excited they both are
I could listen to Phil Plait speak all day.
8:27 I heard someone comment on this before and they said that when Hubble discovered that the Andromeda Galaxy is an entirely different galaxy to our own, our understanding of the size of the universe had doubled overnight. Mind. Blown.
lmao i love how awestruck hank is in this video, like a kid learning about space for the first time!
Since the universe is expanding that means we cannot safely say 10 years from now that the distance of a cosmic object we measured now will have the same value then. To me, that is mindblowing
it was interesting to see Hank wrapping his brain around the answer, especially since he is always the one teaching us stuff.
Best SciShow yet! Bravo!
I can't stop smiling because of beauty of astronomy!
That look of "Oh deer science I love you" on his face when he's told the earth moves. I can just see his brain getting it, and I absolutely love it.
I love that you did a space interview for School of TH-cam Week, my favorite subject.
I just love how mind blown hank looks here
because that is the same expression I had when I first saw this video
Phil Plait is one of my heroes.
The redshift in light is also a very common method for measuring the distance to faint objects!!