Do aliens exist? If they did, would we know? | NASA astronomer Michelle Thaller

Do aliens exist? If they did, would we know? | NASA astronomer Michelle Thaller

One of the biggest questions is, could there
be other life besides us out there in the universe? And I think pretty much every scientist I
know feels that there must be. I mean, just simply the numbers– in our galaxy
alone, there are half a trillion stars. And we’re now beginning to realize that nearly
every star has its own solar system. So at the very least, our single galaxy has
hundreds of billions of planets. And some of the stars out there are even older
than our sun. There may have been a chance for a civilization
to start billions of years before life began on earth. And if that’s true, could there be alien civilizations
out there that are far more advanced, technologically, than we are? The unfortunate thing, of course, is we have
no evidence of this. They’re not making it very obvious. So is there a way that we might be able to
see some of, at least, the artifacts of one of these super-civilizations around a distant
star? And one of the people who thought about this
in a really wonderfully scientific way was a man named Freeman Dyson. And his name got lent to something called
a Dyson sphere. And what a Dyson sphere is– the idea is that
a very advanced civilization would probably need a lot of energy. And one of the best sources of energy is solar
energy, the energy of their star that they orbit around. But instead of waiting for that starlight
to come all the way to a planet, and to get put into little detectors and solar cells,
what if civilization was a little bit more assertive about that, and actually went to
the star and built giant collectors around that star? The idea of a Dyson sphere is probably a bit
extreme, because some people wondered if a civilization could build an entire shell around
a star. And that shell would collect all of the radiation
available from that star that they could use for whatever alien purposes in their super-advanced
civilization. A lot of people have suggested that maybe
a shell wouldn’t be stable. It would be very hard to keep that actually
working and orbiting around a star. So maybe you could make a giant grid of huge
collectors that would orbit around the star and pick up as much radiation as possible. So a Dyson sphere, or sort of the equivalent
of that, there being many, many orbiting detectors around a star, is a wonderful idea in science
fiction. The question is, is there a way you could
detect one of these? And for some time, actually, people have wondered,
what if you saw a lot of infrared radiation, heat radiation, coming from a star-like object,
but you didn’t see any visible light? Is it possible that there was a shell of material
around that star used to collect all of its energy, and that shell was getting warm because
it’s around the star, but it wasn’t letting any light through? There are very serious scientists who proposed
looking for star-like objects that just have heat, but no light associated with them. Unfortunately, we never found any of those
either. A couple years ago, however, something very
dramatic happened. And it happened as part of the Kepler mission. This was a mission that was looking for planets
around other stars. And the way Kepler looked for planets is it
basically looked at a part of the sky where you could see a couple hundred thousand stars
all at once, and it just stared at that for years. The telescope never moved. It looked at the same part of the sky for
a very, very long time. And then over time, scientists looked to see
if the starlight varied. Over all of these stars, could each star be
varying as a planet went around and made a little eclipse so that the planet has to be
lined up perfectly along our line of view– but that can happen, there’s a lot of planets
in many different orientations around the stars in the sky. So if what’s lined up perfectly, you would
see a little eclipse. The planet would go in front of a star. You wouldn’t see the planet itself, but you
would notice the starlight drop. The star would get a little dimmer. So what happens if you notice that a single
star in that field gets a little dimmer every three days? Every three days, there’s the same little
dimming that comes back around, again and again. You realize you have a planet there, a planet,
in this case, that’s orbiting every three days, and blocking out light. Some of the planets we found have larger orbits. We’ve even found planets in earth-like orbits
that go around about once a year. So Kepler found thousands of planets just
by looking at this one part of the sky. Now, normally, when a planet goes in front
of a star, the dip in brightness is very small, less than 1%. If you have a big planet, a planet the size
of Jupiter, and maybe that planet is even very close to the star, it can go down maybe
a couple percent. The actual effect is relatively small. Stars are much larger and much brighter than
any planet going around them. So the dip is just a little dip. And so imagine people’s surprise a couple
of years ago when one of the stars seemed to be going through very dramatic dips in
brightness, as much as 25%. Now, the only thing that could block out 25%
of the light of a star is something as big as another star, and then we would see another
star going around, and that wasn’t there. We’d never seen anything like that before. And interestingly enough, this was something
done by what we call a citizen scientist. There are people in the public who are not
trained scientists who actually help NASA. They kind of comb through our data. And they have no training. It’s almost kind of like a video game format. They actually help us go through the data,
and then they sort of flag things that are interesting. We obviously have computer programs that look
for these variations in starlight. And the computer programs find 99% of everything
that we’re looking for. But sometimes there’s a weird result, something
that doesn’t match the computer algorithm, and the computer throws it out. And that’s what happened with this star. It was such a dramatic dip that it couldn’t
have been real. And not only that, the dip was not symmetric. When you have a little ball, a little planet
go in front of a star, the dip is nice and symmetric. It’s a nice, even, circular shape that goes
in front of the star. This was very weirdly shaped, almost as if
giant triangles were moving across the surface of the star. So scientists did not immediately jump to
the conclusion that, hey, maybe these are giant alien solar collectors. But in the paper that was actually published–
the first author was it was Tabetha Boyajian– they noted that if there were something like
a Dyson sphere, it might look something like this. And of course the press grabbed that, and
it exploded, and people wondered, could we really have found evidence of a super-civilization
around the star. And actually, even myself– this star is about
60 light years away, and is visible through a small telescope. It’s not a particularly bright star, but you
can see it through a small telescope. And I wondered if we could actually prove
that this was artificial. You could go out in your backyard at night,
put a telescope in the sky, and see this little point of light, and know that there was something
wonderful, amazing, a super-civilization around that star. It gave me goosebumps. Of course we wanted to follow up and find
out what this really was. Could this really be giant solar collectors
orbiting around a star? Well, the unfortunate thing is, after a lot
of follow-up and looking at it in many different wavelengths of light, there was a relatively
simple finding that whatever this was made out of dust. It actually bends different wavelengths of
light, different colors, differently, very much the same way that sunlight is reddened
in a sunset. As it actually goes down through the air,
blue light is scattered away, the red light is left, and you have a beautiful orange or
red sunset. And so whatever this is is made out of dust. Unless aliens are particularly good at making
giant solar collectors out of particles that are less than a millionth of a meter across,
that’s not an alien civilization. Instead, we have a new mystery– what is this? There’s a giant, opaque, thick dust cloud
around this star, and it’s very uneven. And people wonder if maybe two planets have
recently collided. Maybe two planets collided and threw up this
giant cloud of dust that’s still kind of settling down. Maybe that’s what we’re looking at. We’re not really sure. But one of the things that I think is really
telling about this is I often get the question, would you hide evidence of a civilization? Say that we had alien bodies or a UFO, or
we’d found signals from space, would scientists hide that from the public? And instead, I think what you saw were scientists
jumping up and down, saying, oh my God, what if this is really something very interesting? We even called our colleagues at SETI, the
Search for Extraterrestrial Intelligence, which is an organization that actually looks
for radio signals around the sky that could be artificially produced. And we asked them to look at the star. They didn’t see anything. So while this one did not turn out to be an
alien civilization, and in fact, we don’t have any evidence of aliens yet, we love the
idea that there could be life out there. As scientists, this excites us. It inspires us. And immediately, even before we knew whether
it was true or not, we were wondering if it could be a possibility. There is no way we would ever hide it. And not only that, but the sky is open to
everyone. There’s no single country that can actually
just– you’re the only people that get to point a telescope up at the sky. There’s no way people could ever be organized
enough to actually hide something like this. And as soon as we thought something unusual
was happening, we followed up. We wanted to know more about it. So OK, no super-civilizations yet, but maybe,
someday, we will really get a signal or see something up there that has to be artificial. And then I will be in my backyard with that
telescope, looking up with goosebumps.

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About the Author: Oren Garnes


  1. They probably do
    The question is whether they would be advanced enough to communicate…

  2. Yes definitely, why even speculate? It’s a ‘when not if’ situation.

    Also, please keep terms like recently to a minimum. In your definition of recently the dinosaurs still ruled earth 😂😊🤔

  3. Michelle is one of my favorite astronomers. And I appreciate how unapologetic her hair always is. ❤️❤️

  4. Not to poopoo a good explanation, but I’m tired of the Dyson Sphere hypothesis as the only thing we can think of. It’s very anthropomorphic. It’s in ratio to our current zeitgeist. Gotta think Bigger.

  5. Well scientists need to start looking at the UFO phenomenon seriously if they want answers.

  6. Oh wow she does all the elizabethan dresses ! Oh she would look wonderfull all done up like that !! Sorry im not being rude but here , we have a scientist that appreciates life before tech thats awesome and very promising for the future , what a wholesome lady .

  7. I feel like fission is the answer to the Dyson dilemma. Fission should be able to produce energy more efficiently than stars can.. per Isaac Arthur.. if an alien civilization perfected fission before they had need for Dyson swarms then it's possible that they can produce more energy than a Dyson swarm would be capable of.

    That's my line of thought atm at least.. I'm sure it will evolve as we learn more.

  8. I think we may never know. Aliens could be living in an alternative reality created by them or using an artificial star to get energy. In any case, I don't think that a civilization like that would explore the universe. It might not be feasible or necessary at all.

  9. NASA knows of alien activity but I think that another part of the government is forcing them to censor all evidence they come across.

  10. Eve pilots, is there nothing we can’t do? We broke their servers with the amount of data we helped cross reference in-game. Coolest thing ever combining space sim gaming and citizen science, glad I’m a part of it.

  11. I always thought the Dyson sphere as a weird theory, I mean if they have the technology to build such a big tool that can do that, I’d have thought they’d have to technology to create and use energy way more efficiently than needing to build such a massive thing and harness energy in an oldfashioned way

  12. There are no aliens. If there are any aliens out there then how come they didn’t visit us? And can they locate Hillary’s deleted emails? Do they speak American?

  13. 9 billion people on Earth, but we looking for intelligent life elsewhere. We are the Aliens and we regroup on Earth because it's a vital planet. And if you wanna meet up with Aliens, you have to plan it. Double Entendre's is your answer. Is there life out there? Their lives are, they're existing with us. Just like in religion, people are made from dust, Dust is a formation of complex particles risen from indescribable destruction of a lifelong process. So will we meet aliens? Probably, but someone or something will have to die.

  14. Neil deGrasse Tyson asked us to ponder the difference between humans and chimps based on roughly 2% difference in genomes. The postulate an additional 2% difference in advance from the human genome. Would we even recognize a being like that? How would we recognize something not even based on DNA or organic chemistry? It boggles m mind.

  15. Likely there are other aliens. Its very unlikely that they live in a slice of space time that their radiation is just precise that it intersects our slice of space time. And if it did then they would probably be extinct by the time it reaches earth.

  16. Diff life forms are very common. Much of them reside in diff dimensions. I'm sure aliens use that here, around us, so we cant see them. It's much like a fish asking if theres more beings out there, unaware that they're ina sea world and theres tons of life around them but they cant reach it since they're in water.

    Astral projection and other meditation abilities help people to access different dimensions. Prophets and others have stated this very much through out the past.

  17. More science videos like this one. Less politics more science. Can we also have another video by Michelle Thaller? I would like to hear more.

  18. Yeah like we'd discover that super advanced alien civilization first, remember the time when chimpanzees discovered Humans.

  19. its like you live in a bubble and are still out of the loop……yet suppose to be current and intelligent, key word Nimitz event

  20. I THINK Aliens are here and have always been here. Maybe they manipulated apes with some type of DNA to create us which is why we seem so much more intelligent and different to other life forms on this earth. As much of an expert as this astronomer is there's a huge chance that if true she doesn't know just as much as us since it would probably be a very small group of individuals that are in contact with them.

  21. They don't exist. It's just demons and the fallen angels. Wake the hell up…. It's past noon already and they are about ready to trell you that you can upgrade your DNA

  22. "Science Communicators" tend to regurgitate the same thing over and over in their cookie cutter responses. There should be more directed innovation towards the more important questions.

  23. yeah we just need to build a phone that has a decimal point on the dial pad and we need to dial 3.6.9 -Mithni Horadine Janvier

  24. There is, but not in the scale you think! Consciousness is a fractal (independent of scale).We are giants made out of trillions of conscious cells,

  25. Plenty of evidence including military radar recordings, you need to tow the party line. Mixing truth with lies makes it harder to establish the reality.

    A Dyson sphere is what we think OUR technological foundation is capable of.

    If they’ve mastered using gravity or dark matter or not carbon based or not bound by the 3D world, we are looking for the wrong signs.

  26. So that star at 60 light years sounds a good candidate for looking for evidence of transuranium elements which are supposedly articificially made and therefore don't exist elsewhere in the universe. It's proximity would make it much easier to detect such spectra.

  27. The only way I believe we will travel through the universe is by way of our mind. Multidimensional transformational travel.

  28. why are we talking about a civilization that builds around a star when you can just make one here and harness the zero point energy field with overunity. iter in france? another one in usa/japan/ germany. the problen with asking people that look "out there" is that they miss all the actual things happening "RIGHT HERE"

  29. Surely building a massive structure around a star would block all the sunlight out for all the star's planets. That would be silly as the people that made the structure would be without light themselves on their own planet….

  30. I understand what is meant by a Dyson Sphere but its really dumb, isn't it? I get that harnessing the power of the Sun is great and getting the energy from the side of the Sun that we don't get is brilliant but why, really why, would anyone think its a good idea to cover the Sun totally, any Star really, so that its light etc no longer reaches our planet. Lets face it the Dyson Sphere would exist in the civilisations own Solar System wouldn't it, so why cut out that energy to our own planet in the first place? I suppose I mean can some explain this to me?

  31. The last time there was massive amounts of public talks on space aliens it was propaganda to cover people spotting secret spy planes during the cold war. This time around its about drones.

  32. A science fiction idea: what evolves is not the matter but the intelligence it self. Then the IA makes sense. We humans are just cocoons. We are caterpillars based on carbon and evolve to butterflies made of sillica

  33. why these people even work for NASA? they are like cartons with no logical minds. earth ( a perfectly habitable planet) only produced life ONCE. Why for 4 billion years a perfectly habitable planet only produced life once? why not 13323 times? this means that even in a thousand earth-like planets life could only happen once and in that rare event life will only be microorganism type of life because almost half the history of life on earth was only microorganism life. and only very few of these planest will have complex life because it is not inevitable it just happen on earth by chance. and even if complex life arises by chance in an alien planet human-like intelligent is very unlikely. it only evolved in the earth 200 thousand years ago. life could have gone perfectly without it. human-like intelligent is not a necessity for survival it only evolved ONCE. eyesight evolved tens of times for comparison.
    these clowns just say things that are interesting in movies and do not do their research.

  34. What if other life evolved into AI. AI that can breath in a Gas Giant Planet. We focus to much in a planet like earth forgetting the life here earth there is a possible will be replace by AI

  35. Imagine the Galactic “Panning Consent” required to build a Dyson Sphere. Main objection would be from Greenpeace.

  36. I think it's time to settle this subject. If aliens were in any form contacted, the government will never tell us. Done.

    PS: I also sell anti mind probing hats. Silver only.

  37. I have to wonder if the people who conjecture on the existence of Dyson's spheres have ever done the math regarding whether the amount of energy required to process and transport all the materials needed to build it would exceed the amount of energy they'd get from the finished sphere. If a civilization had the energy resources to build one why would they need to build it in the first place? And how many solar systems worth of material would need to be harvested to build it?

  38. Dyson Spheres/Swarms or any other mega structure to capture solar energy, convert to electricity, and then transmit that electricity where needed is an old fashioned idea. An advanced civilization would likely just rely on fusion reactors for all their electricity. A fusion reactor would be a portable star and require far fewer raw resources than building a Dyson Swarm or similar mega structure to capture solar rays. A civilization that has licked fusion would be rather impossible to detect using the method described in this video.

  39. Question… Where would the building material come from? I doubt the local solar system could provide a quarter of what would be required.

  40. is it practically possible to create dyson sphere? Bcoz to cover a star require more mass than an earth size planet?

  41. Lady says no evidence of aliens, yet military pilots FORCE the superiors to finally take their clams seriously about constantly seeing UFOs, as written about in the news…

  42. If I was part of an advanced alien civilization, I will never want to mingle with humans at this moment. We still haven't learned to live in harmony and peacefully among ourselves and now thanks to Trump, Putin, Kim Jong Un, the president of China, Salvini, Erdogan, other dictators, dictators wannabe, malicious and corrupted leaders from other countries, extremist religious leaders and their supporters , we are even in worst place than we were 3 years ago. If we as humans don't get rid of those people, their ideology and we keep fighting with each other, our civilization will seize to exist in 20 years.

  43. Glad you mentioned the ufo stuff at the end, I believe scientists would reveal the truth. The government on the other hand … o o o

  44. we humans have only existed for a blink of an eye Considering the age of the universe and the age of the earth. So wouldn't be possible that at this short time of existance we could be alone? Maybe life has existed before us and jas already gone extinct and/or maybe the next life is yet to develope

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