Can Alien Civilizations Detect Us?

In celebration of this channel reaching, and
surpassing, 5000 subscribers here is a long form video made in thanks to the subscribers
of this channel for your continued support. I continue to be surprised at the growth of
this channel and couldn’t have done this without all of you. Many thanks and onward we go! I’m still excited and having a blast researching
and making my videos, and I look forward to many more years of telling you about the cool
ideas and stories that I come across within the world of science, especially astronomy,
and ultimately our progress towards answering the question of “are we alone?”. It’s one of the biggest questions in the
universe from our perspective, and I really don’t think we’re all that far from answering
it definitively, I believe that within 20 years there is a good chance that we’ll
finally know the answer to the question. But when discussing SETI and searching for
alien radio signals in particular there has always been a kind of elephant in the room. Detection is a two way street, and the elephant
is whether they can see us. We know that it should be possible for us
to detect alien radio signals here on earth, or in fact all sorts of biosignatures that
point to life, so long as the signals are strong enough. This goes both ways. In theory, alien civilizations should also
be able to detect us as well. But in practice, this process is a bit trickier. It really depends on what equipment that alien
race has and how close they are to us in space and the same rules apply for us when looking
for them. The one thing an alien race would know however,
assuming that they have powerful telescopes a bit bigger than what we have now, is that
earth hosts life. Life on Earth has a long history and has been
affecting the composition of the atmosphere for billions of years, and by studying earth’s
atmosphere anyone in the Milky Way that’s looking would see our atmosphere as it was
at various stages in the not too distant past. Our galaxy is only about a hundred thousand
light years in diameter, so they would not see our planet as it was during the time of
the dinosaurs, but rather much more recently depending on their distance from us. This is one of those rare cases in our universe
where the distances do not seem so vast as far as geologic timescales go, but even still
it would be very difficult to detect earth from the other side of the Milky Way for a
number of reasons. But for those that can detect us, the easiest
biomarker for an alien civilization to see is our oxygen in the form of O2 and to a lesser
extent, ozone. While oxygen is not a dead ringer for the
presence of life on a planet, it can be abiotically created, we do have an awful lot of it. An abnormal amount. They would also see our water vapor, and taken
with the oxygen that would indicate to them that complex life could exist here. With a sufficiently large telescope, they
would in turn see CH4, methane. With those three markers taken together, they
could reasonably infer that life was the probable the source for those gases. But what else could they know? In a paper by Edward Schwieterman and colleagues,
links to all papers mentioned in this video in the description below, they review all
currently known biomarkers that we can search for to determine if an exoplanet hosts life. It’s worth noting here, and the authors of
the paper state it prominently, that these biomarkers are for our class of organic, water-based
life. There may well be alternative biochemistries
that would have different markers, but we don’t have a clear picture of how those forms
of life might work, or if such chemistries could ever result in intelligence. But in regards to an alien civilization looking
at us, even if they were not carbon-based and instead based on, say, silicon, if they
could build telescopes and spectrographs they would have the scientific capability to know
of carbon’s complex chemistry and suspect that water and organics, both common in the
universe, can lead to life. Organically based alien life similar to us
would already know based on themselves. Many other potential biomarkers that can be
seen on this world. One example is variations in carbon dioxide
levels that occur seasonally as vegetation cycles, another would be the many other gases
such as nitrous oxide and methyl chloride that while they might be individually abiotically
created, when you take them as a whole life becomes the likely source for the profile. They might also see direct reflectance from
our vegetation in the near-infrared. Searching exoplanets for this biosignature
is covered in a 2005 paper by Sara Seager and colleagues, and the technique could equally
be used by an alien civilization looking at earth, providing they know what plant life
is. But even if they don’t, they might still see
that some strangeness is happening with this world in the near-infrared. But what of detecting our civilization through
our technological markers? There are quite a few of these, and the more
developed we become the more important some of them will be as far as aliens spotting
us, such as our waste heat when we start doing things like building Dyson swarms, that eventually
would be visible at much greater distances than anything we are doing now. But as we are right now, there are several
major technological markers that we produce. Before we get to those, it’s worth pointing
out that distance is key for aliens to detect us. We’ve only been technologically visible in
a major way for about a century, give or take. Hypothetically, aliens within a hundred light
years might see the signatures of our technology, but they would see it as it was in the past. If they are close, say Proxima B hosts a civilization
for example, then they would see us how we were a bit over four years ago. A civilization at 50 light years would see
us as we were 50 years ago and so on. But out further than about 100 light-years
or so, using any practical means we become essentially undetectable. And the further you go from there, the harder
it becomes to detect and study earth at all. Within a hundred light-years, there are two
main markers that aliens might detect, and a few peripheral ones. Firstly is radio. We’ve been broadcasting radio waves for
about a century, give or take. Aliens within a hundred light years from earth,
in theory, might pick those transmissions up, depending on what equipment they have. But as a matter of practicality, they might
not. The reason for this is that they would need
some serious equipment to do it. If we took our own current equipment out to
Proxima Centauri and looked at earth, we would not be able see the vast majority of our own
radio signals. Our television and radio stations are simply
too weak. The best chance would probably be radar, and
even then the chances are slim. We have in the past, however, beamed out signals
that were powerful enough, particularly the famous Arecibo signal, but the problem is
that to see that signal, the aliens would have to be looking at just the right time
to catch it. And they would have no idea it was coming. But that’s just judging things by our own
current radio capabilities. They will no doubt get better and more sensitive,
but at the same time the signals we emit are tending to get weaker as we develop. But an alien civilization that has much bigger
radio antennas than ours located close enough to us might just be able to detect us. In an article, Seth Shostak, link below, notes
that evidence of our existence has already reached about 15,000 star systems and if a
civilization had a big enough antenna, he states for example one the size of Chicago,
or may use gravitational lensing to look for us, they might just see radio evidence of
us. The second main way an alien civilization
might detect us is lesser known. Radio signals have always been the assumed
way that aliens might pick us up. But there is another. We also produce a very unnatural form of visible
light that if someone had sensitive enough instruments to detect it, and they would need
to be seriously sensitive, they would know that intelligent life was the only cause. It’s our streetlights on earth’s night
side. In a paper by Abraham Loeb and Edwin Turner
they suggest ways that we might search for other civilizations by focusing on their artificial
light emissions, and by extension how other civilizations might look at ours. By looking at the night side of an exoplanet,
if there is artificial illumination present it would be different enough to be distinguishable
from reflected natural light from the planet’s star. The authors note that we currently could detect
earth-level artificial illumination only within our solar system. If there’s someone hiding out on a Kuiper
Belt object, we can detect their street lights. But no further than that with current equipment,
but as time goes on our capabilities will grow so at some point optical SETI searching
for the lights of civilizations should become viable. If it’s possible for us, then it’s possible
for aliens as well. Another, more novel way aliens might detect
us are concentrations of industrial chemicals in our atmosphere. In a 2014 paper by Henry Lin and colleagues,
they detail that we might look for refrigerants in exoplanet atmospheres to detect alien civilizations;
this would be chemicals like CFC’s. The aliens could likewise do the same with
us, if they were close enough, and see evidence of very long persisting chemicals such those
known collectively as Freon. In addition to signaling active industrial
processes on a world, the presence of these kinds of chemicals could actually serve as
a kind of indicator. If you see only the longer-lived ones, it
could mean that the civilization advanced past the use of those chemicals, or died out. If you see the shorter lived ones, you would
know that the civilization was active. Maybe an alien civilization nearby has the
capability to detect our radar or see our street lights or chemicals. Or perhaps one that is not yet close enough
to receive our signals might some day pick us up. But I would speculate that it’s pretty unlikely
that anyone has, and the further away an alien civilization is, the harder it will be to
detect us. Eventually you just get so distant that you
can’t physically construct an instrument large enough for the task. This undetectability could be a good thing
or a bad thing depending on your perspective, but what it does tell us is that a civilization
at our level of development is very hard to see at a distance. A more advanced civilization should be easier
for us to spot, and if they’ve been around a long time, they would be detectable over
greater distances. But it’s really not something that is so
easy as many might think. But, while this may sound discouraging to
those hoping for a Contact type of numerical signal to come through, radio signals are
not the only way alien civilizations might communicate with us. In fact, it may not even be the most likely
way, we simply don’t know. That same long period of Earth’s atmosphere
being altered by the presence of life also allows for another type of detection of us
and subsequent communication with an alien species. And this one would be far more direct and
real time than radio signals traveling long distance at the speed of light. In the distant past, someone in the Milky
Way may have seen our oxygen atmosphere long before we evolved. They may have thought long term and sent out
a probe, a type called a Bracewell probe, at sub-light speeds. It might have taken 50,000 years to get here,
or a similarly long time, but the fact is, anyone wishing to study inhabited planets
directly merely has to have good engineering and a whole lot of patience. We view time in terms of human lifespans,
which are short but ever increasing, and there’s nothing saying that they won’t continue to
increase until we live for thousands of years. Time and distance become less daunting in
that case. Jason Wright of Penn State discusses this
very thing in a recent paper, link below, that points out that our solar system is ridiculously
old. Far older than our species the tune of billions
of years. It’s been visible for a long time to the entire
galaxy, and there has been more than sufficient time for someone to send a probe. Maybe multiple species have sent probes. Doing so may even make more sense than any
other form of interstellar communication because while it takes time, it’s at least direct
on one end. And some day it may well wake up and establish
contact. Finding such a probe before then would be
a needle in a haystack however, perhaps even harder than detecting a radio signal. With our current capabilities we aren’t
likely to discover it, should it be there, and of course there are always going to be
engineering questions, extreme age issues, self-repair questions, and so on with any
sort of ancient Bracewell type probe. Time is not kind to much of anything, so the
aliens would need to have solved those concerns. But an advanced civilization long ago might
have done that, remember the universe itself is even older than the solar system and there
could be civilizations out there that are many billions of years old. Again, we don’t know, and even finding a
dead probe would be useful. We ourselves have fixed plaques to our probes
in case aliens ever run across them. Any active probe would certainly have watched
us evolve and develop. In addition to collecting data on Earth, perhaps
they’ve enclosed a copy of something like science fiction’s Encyclopedia Galactica,
edition of ten million years ago, that tells us the secrets of the galaxy and the civilization
that sent the probe. The information would be outdated, necessarily,
but information from an ancient civilization would still be excellent information indeed. And, after enough time has passed, they too
will get word from their probe that humankind has achieved civilization and they can update
their encyclopedia to include us. But there is one last, unfortunate way that
we might detect an alien civilization or they might detect us. This would be if we, or they, destroy ourselves. In a paper by Adam Stevens and colleagues,
they detail several ways in which we might detect alien civilizations that have recently
destroyed themselves. The rules on that kind of a detection also
apply to us and while it may be a depressing way to detect an alien civilization, it’s
still a scientifically legitimate one. I’m a positivist and I like to think that
our first detection of an alien civilization will be an amazing experience, or it may even
be a mysterious experience, such as the detection of some civilization’s Dyson swarm but with
no other information. That said, civilizations probably do destroy
themselves, so we should know what to look for. The first way is through the detection of
a nuclear war and its aftermath. Nukes produce a distinctive “double flash”
of gamma rays in their detonation. In fact, when gamma ray bursts were first
discovered one of the possibilities on the table for their origin was alien nuclear testing. This isn’t automatically a bad thing actually;
there are ideas out there on how to push a spacecraft to great speeds using hydrogen
bombs as the propulsion method. Subsequent observation of GRB’s ruled that
out however, and those things are far more powerful than any conceivable artificial detonation. But a big enough nuclear war itself should
be visible at a distance if aliens destroy themselves provided that they are seriously
armed to the teeth. If we did it however, surprisingly, it would
probably not be detectable very far out due to reductions in US and Russian nuclear arsenals
over the years. Atmospheric effects of such a war on earth
would be visible however, at least for a short time. Nuclear war kicks up a lot of dust and nuclear
weapons produce a lot of weird ionization of the gases that make up earth’s atmosphere. It’s worth noting here just how powerful
the effects of these weapons can be on a planet. The following series of pictures are from
a nuclear test done by the United States called Starfish Prime in 1962. A hydrogen bomb was detonated in space and
it caused strange bright auroras along with an unexpectedly powerful EMP that knocked
out power stations in Hawaii, and wreaked lots of weirdness on the earth’s magnetic
field. That test was probably not the best idea,
and did have some long lasting effects; in fact it damaged a significant portion of the
satellites in orbit in those days. That said, the entire solar system saw that
one and maybe further out did too, though the effects of a nuclear war anywhere it might
happen in the universe would be pretty short lived and we, or the aliens, would have to
happen to be looking at just the right time to see most of those effects. That’s statistically pretty unlikely. But nuclear weapons aren’t the only apocalypse
that would leave a detectable mark. The paper continues to detail the effects
of biological warfare, in particular if that warfare was cross-species and beyond devastating
to an inhabited planet’s biosphere. Specifically, assuming a world has anaerobic
bacteria, distinctive solely biotic chemicals would be produced by the decay of biomatter,
i.e. corpses, and would be detectable in a spectrum for a time. If you detect it, it means life was recently
there, but much of it maybe there no longer. Thankfully, at least as far as what is public,
no one on earth has ever developed this level of biological weaponry, and in fact biological
weapons on earth are pretty limited on purpose and, as far as we know, we can’t destroy
ourselves with what we have. Hopefully, cool heads will continue to prevail
in this matter. But an alien civilization might not be so
restrained, but again this sort of biosignature would be very short lived and for us to see
it with an exoplanet we’d just have to happen to be looking at just the right time. But there is one last possibility that we
might see with an alien civilization that they would not see with us, since this technology
is still largely only hypothetical here. It’s the Grey Goo, or molecular nanotechnology. This could be, if the engineering pans out,
one of the most potent weapons in the universe. The idea is to create a self-replicating nanodevice
that consumes matter to create copies of itself. It can do so on such a scale, exponentially
reproducing, until it consumes a planet, or at least a large part of one. The authors suggest that this technosignature
would be visible for a much longer period than the others, on the scale of thousands
of years. But I suspect that we won’t see much in
the way of apocalyptic markers in our search of the universe. And I don’t think anyone will see them with
us, or at least I hope so. But in the end, earth is not really all that
detectable to aliens and aliens at our level of development would not be all that detectable
to us. More advanced species would be, but there
doesn’t seem to be one of those close by, so I would imagine it’s a good bet that
no one knows that we’re here. Yet. Thanks for listening! I am futurist and science fiction author John
Michael Godier currently eyeing my wireless router suspiciously and wondering what it’s
telling the aliens, loose lips sink ships! and be sure to check out my books at your
favorite online book retailer and subscribe to my channel for regular, in-depth explorations
into the interesting, weird and unknown aspects of this amazing universe in which we live.


  1. JKay11235 said:

    They already did.  They're already here.  And if they can get here, they're thousands of years ahead in every aspect.  They're smart enough to see several steps ahead and understand the implications of revealing everything.  They're letting us be, until it's the right time.  They'll probably reveal themselves just before we're about to reach the point of no return of destroying ourselves.

    May 2, 2019
  2. judd thweatt said:

    John your voice has me convinced we are not alone…

    May 3, 2019
  3. Oxyaena said:

    "Yet." Jesus

    May 21, 2019
  4. Nick Peterson said:

    Best space channel on YouTube hands down. Great topics made and told in an interesting way.

    June 1, 2019
  5. luis duron said:

    Give or take

    June 6, 2019
  6. luis duron said:

    We don't know!

    June 6, 2019
  7. luis duron said:

    Star war or what!?

    June 6, 2019
  8. Ollie OJ Fowler said:

    I hope we find other living organisms in my lifetime.

    June 16, 2019
  9. fish fishy said:

    Background music still too loud. Turn it down. Annoying

    June 26, 2019
  10. Stephanie Drake said:

    Personally, I don't think we're alone, we're LEFT alone until we can show evidence that we are worthy of being part of an interstellar community.

    Like Star Trek, we are a "pre warp" civilization, when we develop the technology to leave Earth and our solar system, then we will be ready.

    June 26, 2019
  11. Kanade Tachibana said:

    Super monotone voice

    "I am still excited"

    June 29, 2019
  12. Pascal ÓMathghamhna said:

    Clear, concise, scientifically precise & with the right amount of detail not to be boring. Keep up your good work.

    July 7, 2019
  13. Erasmus SixFiftyFour said:

    We have come from far, far away to give you energy efficent……refrigerators! We just LOVE to serve man! 😉

    July 10, 2019
  14. Bubbles said:

    Light orbs , stand outside at night and look up , wait a while when you see one think about it , try to communicate with your mind , think good thoughts and the orb might visit you and start to communicate in some form . I found they fly by very high in the sky at first than they light up getting brighter and dimmer as a form of communication then they change flight patterns and a couple years later if you're lucky it will show up right in front of your face . A ball of light around 7 are 8 feet round . My girlfriend was with me when the orb showed up she was scared and ran in the house i haven't seen any orbs since . I think the orb was warning me about the woman i was dating at the time we are no longer together . Was it a ghost was it a passed relative maybe a Alien we really don't know at this point and what about these new tic tacs . . . Interesting subject .

    July 16, 2019
  15. Aaron Jackson said:

    @Mr.JMG; Your videos are great and thank you for them, but please, please, please!!! Can you turn the background music DOWN, so we can hear you better! I'm very interested in all you have to say,but I'm having a difficult time hearing you, as the background music is so damn loud!

    July 17, 2019
  16. Zeno 13 said:

    Love your videos grettings from the far away albania

    July 24, 2019
  17. Spencer Davis said:

    15:05 "That test was probably not the best idea." That is the understatement of a lifetime.

    August 2, 2019
  18. GB Spence III said:

    If employed correctly, nuclear weapons don’t kick up a lot of dust. To maximize blast and thermal effects, as was done in Hiroshima and Nagasaki, nuclear weapons are detonated thousands of feet above ground level. And for this reason, Carl Sagan’s nuclear winter hypothesis is probably wrong.

    August 4, 2019
  19. Andrew Hislop said:

    Only the drunk ones.
    They get boozed up and crash their space cars.
    And/or preform bum sex on the locals before going home.
    What happens in earth stays in earth.

    August 4, 2019
  20. Frederick John Picarello said:

    Time is a funny thing so to speak. Even though it takes light from some stars mllions of years to reach us & the same for our light or messages to reach alien life far away' just say hypothetically we could snap our fingers & be wherever we were trying to reach alien life would essentially be the same moment in time. Whether that alien life was far behind us technologically or far ahead..Once we are able to bridge that gap in distance we will also do the same for time..

    August 5, 2019
  21. Richard Head said:

    What if Aliens were far far behind civilization and have no technologies. They only use their sense of smell to detect other Alien life or they just howl to let other planets know they’re there but the planets are way too far from each other and no one can hear them.

    August 6, 2019
  22. Y2kSd4 said:

    I like this Guy , very well balance with the actuality science and his politics. AS well the possibility of the science fictions and his poetics theories!!!

    August 6, 2019
  23. David Alder said:

    You sound like Kurt Loder .

    August 6, 2019
  24. Kuiper said:

    This channel is the shit!

    August 11, 2019
  25. Micah Leis said:

    I really enjoy your videos but the background music in this particular video was too loud. It detracts from your commentary and makes listening to it uncomfortable. Less music, more JMG.

    August 14, 2019
  26. Stiffu san said:

    Such a monotone way to speak

    August 15, 2019
  27. Ro Robert Grubbs said:

    many of us from the planet x are here on Earth now we have leaders here on Earth Kim in North Korea y Trump here in the usa

    August 15, 2019
  28. Miguel Vega said:

    Your voice is amazing👍

    August 17, 2019
  29. Paublus Americanus AMERICANUS said:

    they already did thousands of years ago. Just that we are so conceited we think they don't exist, just like when we thought the sun went around the earth. Same thing with these aliens, they do not conform to our ideas of right and wrong, what is or is not possible, because hey, they've been around for far longer and have different ideas about reality.

    August 17, 2019
  30. Gordon Welford said:

    You humans ask some really, really dumb questions.

    August 19, 2019
  31. Mike Stevens said:

    Bravo , I like metiorites , I need to learn about rare ones , nonstandard , weird ones , Stony an nickle iron , I get , I dread tossing something I didn't know about , hint hint

    August 20, 2019
  32. Elwood Sherman said:

    You couldn't have done it without that voice of yours, very soothing to the ears.

    August 24, 2019
  33. Robert Buce said:

    I'm glad that you had the intelligence to actually mention it, but I do not agree with your view regarding nuclear weapons detonations being a less significant signature event. I actually believe they would be and likely are one of the biggest signature events that man has ever produced that would be potentially seen as far out as about 60+ light years by now. The high energy bursts of Gamma and X-ray energy produced by above ground nuclear blasts would send out un-natural energy pulses that would travel at much greater power than human created radio waves, and thus would be detectable at much greater distances. With so many above ground detonations and space detonations that have taken place here, it substantially increases the chances that an advanced alien civilization would detect what was going on here and potentially want to investigate further….possibly leading into their more closely monitoring this solar system and eventually detecting even more through some of the other means that you mention…because now they would be watching.

    August 25, 2019
  34. Rocflanagan said:

    0:57 yes and they've already blocked us on social media.

    August 25, 2019
  35. Za Z said:

    There will only be a few planets that have life. There are just too many things that have to line up! Magnetic field, a moon to stabilize wobble, a near perfect orbit around the sun, seasons to perpetuate winds and currents to spread life, the right amount or water to not dry out, tectonic plates, For our planet to have heavy metals there had to be a star nova near us before earth formed. The planet has to be at the right distance from the star. Its going to be harder than even Frank Drake with that famous drake equation said! And then we haven't even gotten to the chance of intelligent life evolving! The Drake equation was written in 1961 by Frank Drake, not for purposes of quantifying the number of civilizations, but as a way to stimulate scientific dialogue at the first scientific meeting on the search for extraterrestrial intelligence (SETI) Stars in the milky way that we know of today? Stars: 250 billion ± 150 billion

    August 26, 2019
  36. kevin dube said:

    Looking at us through sun transit they might see our satellite spinning around earth… in lights years

    August 27, 2019
  37. Lorefin Stardust said:

    Imagine theres an alien civilization that starts picking our signals and they hear a lot of radio broadcasts daily and their whole civilization changes because they too believed they were alone….
    Now they understand that we talk a lot, broadcast is going non-stop and our speech patterns is rather energetic, excited, funny , sometimes serious but it gives vibes we're emotional species and we rather speak with positive emotions..
    So the initial panick isn't so strong because they deduct we might start to talk to each other etc

    August 27, 2019
  38. PVip VI said:

    "Can"? Possible but…unlikely… I have this never before theory: speed slows time – right? Well, if the galaxies are speeding away – it is possible that our light has not reached a lot of civilized Worlds and vice-versa. We may be looking at a galaxy full of life…in 10,000 years from the light that's reaching us. Remember that Earth is 4.5 billion years old so, if an alien is looking at us from 4.5 billion and 1 light years away, we don't exist yet.

    August 27, 2019
  39. Ryder Pace said:

    I didn’t graduate. I failed bad at high school but I’ll sit on YouTube and watch this stuff all day and learn. Space is my favorite!

    August 28, 2019
  40. jbwilk511 said:

    I have to tell you sir..I found your channel a couple weeks ago and absolutely love your content..the best thing to me tho is hearing you celebrating 5k subs in this video and looking up to see you have 175k now…you damn well deserve it my friend..keep up the fantastic work and I look forward to reading your books now as well…cheers

    August 28, 2019
  41. Cooper Cooper said:

    Imagine the telescopes they probably have,,,they know we are here!!!!!!

    August 30, 2019
  42. Cooper Cooper said:

    Think about it!

    August 30, 2019
  43. Cooper Cooper said:

    Who knows what they can see or do,,,,, just because we are stuck by light don’t,,,(don’t) mean they are,!,! Use your brain 🧠!

    August 30, 2019
  44. Jeffrey Stroman said:

    This channel is a blessing, that is all.

    August 30, 2019
  45. T OB said:

    I found out that in the olden days they sent up a space probe Called Voyager that is alive and well and heading out to deep space… . With all kinds of technical data about us and…OUR ADDRESS AND HOW TO FIND US!!!! .ARE YOU FRIGGING OUT OF YOUR MINDS!!… OH, THANKS A LOT NASA!! …. The Native Americans centuries ago were smart enough not to do that even though eventually the Europeans found them and we all know how that ended up!

    August 30, 2019
  46. Prog Man said:

    What about the huge gamma ray bursts that occurred during the nuclear testing of the 1950s and 60s. Wouldn't they be powerful and distinct enough to penetrate long distances through space?

    August 30, 2019
  47. Michael John Little said:

    As Blondie once said “You keep me hanging on the telephone…”

    August 31, 2019
  48. Steve G said:

    0.45…”within 20 years we’ll finally know the answers to the question”…..don’t have to wait 20 years…..see ‘to the stars academy’ it’s now rolling out.

    August 31, 2019
  49. Phillip Honeysett said:

    Detect to sence n above all circle n ball n pic if et see point show the side way or wall a touch

    September 1, 2019
  50. skankhunt 42 said:

    sorry butcoul the narrater please slow down and sound a tad more interested in what he is saying?the full stops in the script allow for a pause lol

    September 1, 2019
  51. fantasyexctasy said:

    200 years from now after we made first contact and future anthropologists look to do research about what humans in the 21st century used to think about first contact, they will find this channel and see that we believed it was inevitable

    September 2, 2019
  52. Joel Bratland said:

    Is there any scenario that involves us detecting them, (dyson sphere/swarm or otherwise) and they wouldn't be able to detect us?

    September 2, 2019
  53. AnnoyedLawStudent 87 said:

    It's probably a bad idea broadcasting our presence and location throughout the universe.
    .. we have ZERO clue what is out there. But, I'd imagine that whatever is out there wouldn't be friendly. It would likely view us as Ants and want to destroy us in order to use this planet

    September 2, 2019
  54. Shpinzy Productions said:

    Alien civilization, Made you . Look up Sumerian cuniform , a good place to start

    September 3, 2019
  55. BlackSuave44 said:

    Why don't we just kick probes out into space once every decade.

    September 4, 2019
  56. Jes Chr said:

    Videos like these are proof that we humans are just too damn stupid. You'd think with our knowledge of physics and relativity, that we'd understand that once we detect their signatures (light/radio waves), they would have already disappeared and gone extinct by then. We see starlight from stars as they were millions of years ago. we don't see starlight coming from a star and think that we are seeing that star as it is concurrently.

    There are literally NO videos on youtube about aliens where this principle is brought up. I do believe there is an abundance of life in the universe. But I think that advanced alien life are rare and they don't last very long at all. When we do detect their signatures one day, we detect them as they were millions upon millions of years ago and they would have long perished by then. We are on the same path. We humans will be long gone way before we detect any advanced life in the universe.

    September 4, 2019
  57. GH1618 said:

    Yes, but after watching Parliament’s comic mishandling of Brexit they decided we were no threat.

    September 5, 2019
  58. Slaughter Them said:

    You better be doing this for many years to come my dude well I really really hope you will be love your content and it's not hard to tell you definitely do your research and pay attention to the little details and your editing is very good as well. In my opinion all this goes a very long way to get me to continuously come back for more.

    September 6, 2019
  59. perry92964 said:

    i dont think any signals would make it very far because space is filled with dust and rocks and gas and that would filter anything trying to get through

    September 6, 2019
  60. Shawn Elliott said:

    "Grey Goo" is far less of a threat than it's made out to be. Machines of any type need to be made from specific materials in specific configurations in order to work correctly; you can't build a semiconducting microprocessor out of iron, for example, because iron has no semiconducting properties. As a result, only a small percentage of the Earth (or any planet) would be useful for self-replicating nanomachines, and the rest would have to be pushed out of the way, and that would require energy. Furthermore, the nanomachines would need to move themselves out of the way to expose fresh raw materials, and that would take even more energy. So even with optimal resource availability (such as a hypothetical planet made out of just the right proportions of the required elements with nothing else in the way), energy would still be the limiting factor. The "Green Goo" that we evolved from has had 3.6 billion years to consume the Earth and has only succeeded in thoroughly assimilating the top few feet, with a smattering of assimilated material penetrating perhaps as far as a mile into the bedrock. "Grey Goo" would not be significantly more successful, because most of the materials it requires are in fact rarer and harder to process than the materials we require. (which is, of course, why the type of goo that evolved on Earth is green instead of grey in the first place.) "Grey Goo" would be a cool way to mine for rare earth metals, though.

    September 7, 2019
  61. rockey rocket said:

    Considering the size and the age of the universe, scratch that, the vast number of stars even within a few hundred light years there has just got to be a vast number of alien civilizations looking at every dot in their sky in exquisite detail. We have probably been under the microscope and at the very least put down in the " for further study" column by distant neighbors. That being said, if we really want to speed things up the thing to do is set up the equivalent of S.O.S. on the beach and wait a century or two for them to send us a return message.

    September 7, 2019
  62. 12inchRules said:

    That background music is too loud.

    September 7, 2019
  63. Teddles Peddles said:

    Radio waves to detect alien life forms is laughable, learn to read light SIGNALS when they are here trying to communicate with us🦂

    September 7, 2019
  64. Jay Gee said:

    we've been broadcasting since the 30's so anyone within 90 light years might be able to hear us.

    September 7, 2019
  65. Dennis Vance said:

    Our television signals have been detected by an alien race who modeled their civilization after our “historical documents“. They are called Termites or Dalmatians or something like that.

    September 8, 2019
  66. alnot01 said:

    One day we may discover evidence, in the form of waste heat and/or radio/laser signals, that there is another technology using civilisation within 25-50K light years from us. That will be definitive answer. If we are alone in the Milky Way (which I suspect is the case), we will not know that "definitively" for many hundreds of thousands of years. Because a definitive answer will require sending a probe to the other side of the galactic nucleus.

    September 8, 2019
  67. robert victory said:

    they are trying to avoid us.

    September 8, 2019
  68. D&D Operations said:

    Not a good idea to splash in the ocean at night. It draws in predators. I’d imagine the universe is just a vastly expanded version of our oceans. Best to tread lightly. You never know when a shark will come in and eat.

    September 8, 2019
  69. Elementalist said:

    5k subscribers. I am watching in 2019 and you are on 184k subscribers! Guess you really got popular over the last 2 years.

    September 9, 2019
  70. Blayne Miller said:

    I honestly wonder how we would collectively react when it widely became known that some sort of alien fleet had entered our system and was slowly making its way here.
    All we would know is that they exist and seem to be headed our way. Imagine how we would react, long before they even arrive here.

    "Alien Fleet Enters System"

    Just think about that situation for a moment, and what our collective mindset would be. In one singular instant everything we know changes.
    In just one day we learn that not only is there other actual, intelligent life, besides ourselves, in the universe, but
    this means weren't alone after all, and never really were, and also strongly implies that there are perhaps many, many more forms of intelligent life as well.

    "We Are Not Alone – But We Are Afraid"

    No government could suppress that knowledge very long, and I'm not even sure if they would try. Probably, I imagine. But both amateur and professional astronomers alike – along with every form of media out there – would make that nearly impossible. I could see professional astronomers along with news agencies and most every other form of media going against any "gag orders" from whichever government and publishing everything they learn up and until the point they are shut down or, god forbid, imprisoned. (To hell with the repercussions to their careers at that point, one would think.)

    "Alien Arrival Imminent"

    Oh and uh, they are on their way here.

    What the hell would we do? How would we react?

    I would love to read a book or see a movie that just played with this concept – starting with the moment we become aware of their existence up to the point at which they get here.
    Nothing else, just our reaction to the concept of finally knowing we aren't alone, immediately followed by the enormous can of worms hat opens.

    They are coming here.
    What do we do?
    What should we do?

    September 14, 2019
  71. michael wier said:

    Is it possible that alien life had detected gamma ray bursts from our above ground nuclear testing from 1945-1963 and decided that what ever life was there has just destroyed itself and turned their eyes elsewhere? Just a thought.

    September 15, 2019
  72. Alexander Karl said:

    were lost in space bro lol

    September 16, 2019
  73. undra johnson said:

    There is life on all 9 plants,the the gas gaint and Neptune and Uranus have only a few SPIECES Not like the inner plants to many Spieces!

    September 16, 2019
  74. Sagezilla said:

    What makes you think aliens listen to sound? Or, use sound?

    September 17, 2019
  75. Simon Sozzi said:

    No! We're in a tiny radio bubble. Teeny…tiny…itty, bitty…

    September 17, 2019
  76. Didu Tasev said:

    Is there any way of detecting primitive civilizations? Like bronze age ones?

    September 19, 2019
  77. topopops said:

    A great no bullshit small channel.

    September 19, 2019
  78. zapfanzapfan said:

    From 5k to 188k in just over two years is a pretty good trajectory 🙂

    September 24, 2019
  79. Hilko van Walraven said:

    park a probe on the edge off the sollar system with proximity activation

    September 27, 2019
  80. Bob S said:

    Human intelligence has not passed the test of time as has instinct. Extremes tend to not last so it could be that what we call progress leads to our demise. Also natural events such as volcanoes and asteroids can throw a wrench into our future. My point being that alien civilizations may be limited in their progress beyond a certain point would make highly advanced civilizations rare or non existent. The only thing certain is change.

    September 28, 2019
  81. Darth Rock said:

    Love your vids/discussions… but I do have to point out that in this instance, all of your assumptions are based on what 'we' do/have/thought processes. Alien civilizations may not even conceive of CFCs/radio/ or any other 'human made' effects. Their thought processes/knowledge of the sciences would/could be completely alien. Assuming they would be knowledgeable of how we would detect them/how they could detect us; and the sciences behind could/would be radically different than what we perceive/know. Their thought processes could be so alien that our 'methods of detection' wouldn't be even a possibility for them to consider. We could be completely undetectable to them because odds are, they wouldn't 'think' like us. And that's probably why we haven't detected them yet either. Because their 'sciences/technologies' would be so radically different than our own, that we couldn't even conceive of 'looking' for them. To say that 'science is universal and any advanced civilizations would base their technology on known universal science' is arrogance. It's only 'universal' at this time and understanding because we, so far, are the only intelligence in the known universe and have nothing else to compare it to. Their understanding of 'our' sciences is equivalent to the ant understanding how the bumblebee flies and the bovine understanding how a fish breathes underwater… Anywho… love your discussions. They always make me think. Keep it up.

    September 28, 2019
  82. James Gray said:

    So what if they can ?? Like we can stop it ??

    September 30, 2019
  83. Feroxing12 said:

    i don't know in some other pop physics video they said radio signals are destroyed after some distance and it would look just like some random noise for the aliens.

    October 8, 2019
  84. Paul said:

    Music is too loud mate

    October 9, 2019
  85. Vladimir_Bone Spur_tRump said:

    music is too LOUD!

    October 13, 2019
  86. Chris Seymour said:

    U dont think they have equipment sophisticated enough to to pick up on us lol cmon….they already know about us, they've known for thousands of years, they are always monitoring us and our progress, to see if we are about to do anything dumb that can harm the universe we all share like set off a bunch of nuclear weapons.

    October 14, 2019
  87. Chris Seymour said:

    I believe dinosaurs exist on other planets in the universe, maybe even our galaxy. Why not, they were here. How cool would that be to snap some photos of actual living dinosaurs from a probe.

    October 14, 2019
  88. Gary Morrison said:

    It’s hard to fully grasp just how stunningly weak our radio/TV transmissions are by the time they reach a different stellar system (and the reverse). The distances involved are unfathomably huge; apply the Inverse-Square Law to that, and…

    One might counter that they may have vastly more-sensitive radio telescopes to hear us with, but I don’t think that’ll help: Noise will ultimately drown out our signals! In other words, it won’t matter how sensitive their radio telescopes are; outside of several tens of light years, they’ll just hear noise more clearly!

    October 15, 2019
  89. Bertie Pimplebum said:

    Can Aliens detect us? Ha ha ha ha ha ha ha ha.
    We ARE the creation of something E.T. They know everything about us past, present and future. (UK)

    October 17, 2019
  90. Johnnyrebbecca Holt said:

    I would love to communicateing

    October 17, 2019
  91. Monster Mousse said:

    What if…………..
    We received an alien probe, but the very size of it is complicating?
    If the alien race were either really small and the probe was nearly invisible? or
    if they were very large and the probe was the size of earth?

    October 18, 2019
  92. jim smith said:

    They hear us they just don't want to talk to us. Switch on the news to find out why.

    October 20, 2019
  93. Corbin Hales said:

    Love your channel. Keep it up!

    October 22, 2019
  94. yo wtf put the mask back on said:

    there are only two answers to the "are we alone" question, "no, we are not alone" and "we dont know if we are alone"

    October 23, 2019
  95. jetthelooter said:

    By the time a radio signal reaches a planet occupied by life capable of faster than light travel, our galaxy will have collided with andromeda galaxy and our sun will have gone red giant and swallowed the earth….

    October 29, 2019
  96. Will Kershisnik said:

    No, there are no others, we are the only ones

    November 1, 2019
  97. Ger Loke said:

    The short answer, yes. They know we exist a long time ago. We also know that they exist a long time ago.

    November 7, 2019
  98. Theninjagecko said:

    Such a great channel totally ruined by the amount of adverts.

    November 7, 2019
  99. J FIzzLE said:

    Always blows my mind,love your vids!!!!

    November 8, 2019
  100. Denis Goddard said:

    @13:19 “I’m a positivist …”
    I do not think that word means what you think it means 😉

    November 9, 2019

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