As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or another sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or multiple species) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? I would again wager no to this.

Alternatively, if the dinosaurs were still around (instead of say humans), is it likely that one or more of their species would have evolved to a technological state? That would probably be another "no".

Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

In the event that the great filter is actually after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10 000's of years from now, technological civilizations would be more abundant, and thus, have likely been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (TMT, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky exoplanet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or another sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before. If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky exoplanet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or another sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species which evolved to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves - i.e., something we can detect).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around?

And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak.

It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky exoplanet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or another sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky exoplanet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or aother sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (TMT, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky planet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or aother sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before. If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to.

By detecting/observing a rocky planet's atmosphere to sufficient levels/precision, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or another sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before. If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to. By detecting/observing a rocky planet's atmosphere to sufficient levels, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take. Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes or aother sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories/mechanisms for how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before. If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), or some other mass extinction event didn't occur in the past 10's of millions of years, is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to. By detecting/observing a rocky planet's atmosphere to sufficient levels, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes and other sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories of how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid hadn't hit the Earth 10's of millions of years ago (possibly combined with a giant volcanic eruption around the same time), is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to. By detecting/observing a rocky planet's atmosphere to sufficient levels, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes and other sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories of how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism without contradicting the following arguments).

Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid (possibly combined with a giant volcano), is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.

In the coming few decades, we will be able to test this further. Our next generation of telescopes (thirty metre telescope, JWST) will probably be just shy of being able to learn much about the atmospheres of rocky exoplanets, but, the generation of telescopes after that (like 15-25 years from now) would be able to. By detecting/observing a rocky planet's atmosphere to sufficient levels, we can learn about the gasses in their atmosphere, the depths of those gasses, and, the abundances. This can tell us a lot about the planet's potential habitability, as well as, possibly tell us whether there is already life there (through biosignatures).

As a scientist who has researched this in quite some detail, here's my take.

Anything outside of our galaxy is pretty much irrelevant, unless travel via wormholes and other sci-fi mechanisms becomes possible. Who cares if there's aliens in a neighbouring galaxy, if, they or we can never meet them.

So, zooming into our galaxy.

Given what we know about the habitability of exoplanets, and with how many exoplanet systems there likely are in our galaxy - there are likely thousands (or more) of planets in our galaxy which could host Earth-like life.

There are different theories of how life began on our planet (which, if you're religious, you could invoke God to have caused this mechanism). Regardless of said mechanism, it seems to be the case that given the right conditions (for long enough, 100's of millions of years to about a billion years for a decent estimate), life will eventually begin on the planet.

By this logic, it is almost inevitable that there is life, of some form, somewhere else in our galaxy. Most likely, it is rather abundant. This might just be single-cell organisms, or, multi-celled creatures not too different from mammals, reptiles, and so forth. This is part of what is known as the Drake Equation.

However, this brings us to the rest of Drake's equation, and, the Fermi Paradox. Long story short, under the assumption that all claims of alien visitors to Earth are false (which is where I stand on this), other technological civilizations are unlikely to exist, and if they do, there aren't very many of them at this present time. We would have seen/detected them by now, in some form, by now, if they were abundant. They would have to be pre-industrial, or, far more advanced than us, to avoid detection.

This begs the question, if life is abundant, why is it the case that not many of these planets have a species (or more) which evolve to a technological state? (Technology is defined here as being able to produce artificial EM waves, such as radio waves).

The possible answer to this is known as The Great Filter. It is unknown if this "filter" is before or after our current point of evolution. I would wager it is before.

If it is before, this implies that something prevents the start or evolution of life to our technological level (or beyond). This could be anything that causes mass extinction of most species on the planet. Natural causes such as giant impacts (asteroids), volcanoes, solar mass ejections, long ice ages, nearby supernova explosions, and so forth. These things can be more common on other planets, which would otherwise be "habitable".

Ponder this, if an asteroid (possibly combined with a giant volcano), is it likely that humans would have evolved? Given that the dinosaurs would still be around? And is it likely that if the dinosaurs were still around, would one or more of their species evolved to a technological state? I would again wager no. Which goes to show how lucky we are in a sense (or, if you are religious, you can again invoke God to clear the field for us, so to speak, by getting rid of the dinosaurs).

If the great filter is after our point of technological development, it cannot be too far into the future, because again, if it were 1000's or 10000's of years from now, technological civilizations would be more abundant, and thus, have been detected. So, this could be something like we (accidentally) extinguish ourselves via nuclear weapons.

Another hypothesis to explain the loneliness of the galaxy is that we were early to the race, so to speak. It goes like this: it takes a long time for technological civilizations to develop after a planet is formed, taking Earth as the sample size of one, it could be of order ~4-5 billion years. Based on our understanding of our galaxy, star formation, and planet formation, Earth could be one of the older planets in the galaxy (perhaps in the top 10-20% for age, haven't looked at these numbers specifically). In which case, we might just have been one of the first planets in our galaxy to develop a technological civilization.

I'm personally not a huge believer in that last explanation (fairly sure there's still 1000's of planets older than Earth in our Galaxy, making this hypothesis mostly a moot point). But even if it were true, it doesn't contradict the possibility of us being alone in our galaxy.