Why haven’t we found aliens? A physicist shares the most popular theories - Brian Cox

[AsleepInYorkshire]

Brian Cox: Why haven’t we found aliens? A physicist shares the most popular theories

There are a few theories as to why we’ve never found other intelligent life in our Universe. Physicist Brian Cox walks us through them.

A 13 minute video.

AiY(D)

[odysseus2000]

Brian Cox: Why haven’t we found aliens? A physicist shares the most popular theories

There are a few theories as to why we’ve never found other intelligent life in our Universe. Physicist Brian Cox walks us through them.

A 13 minute video.

AiY(D)

The usual arguments.

Another way of looking at this issue is to ask: How do we know there are no alien civilisations?

A second question would be:

How do we know we are not being observed & visited by aliens?

Current answers to these questions are very limited & are at least as difficult to justify as statements: We are the only civilisations.

We do not know this, we only know that there is no scientifically accepted evidence of aliens although the Nazca remains are an intriguing mystery & there is now consensus that there are uap, but without any knowledge as to what they are.

Regards,

[Charlottesquare]

Brian Cox: Why haven’t we found aliens? A physicist shares the most popular theories

There are a few theories as to why we’ve never found other intelligent life in our Universe. Physicist Brian Cox walks us through them.

A 13 minute video.

AiY(D)

The usual arguments.

Another way of looking at this issue is to ask: How do we know there are no alien civilisations?

A second question would be:

How do we know we are not being observed & visited by aliens?

Current answers to these questions are very limited & are at least as difficult to justify as statements: We are the only civilisations.

We do not know this, we only know that there is no scientifically accepted evidence of aliens although the Nazca remains are an intriguing mystery & there is now consensus that there are uap, but without any knowledge as to what they are.

Regards,

I put it down to distances and speed of light limitations. They are there, we are here, never will the two meet.

I am yet again reading once more HHGTTG (Am on book two) and can but live in hope, however unlikely, of communication.

[NotSure]

.....and can but live in hope, however unlikely, of communication.

Probably best you do not read The Three Body Problem...........

[doolally]

Another way of looking at this issue is to ask: How do we know there are no alien civilisations?

A second question would be:

How do we know we are not being observed & visited by aliens?

Regards,

A third question would be:
How can you prove a lack of something?
doolally

[odysseus2000]

Another way of looking at this issue is to ask: How do we know there are no alien civilisations?

A second question would be:

How do we know we are not being observed & visited by aliens?

Regards,

A third question would be:
How can you prove a lack of something?
doolally

All that can be done is to set limits.

So for example you can say that at the limit of radio reception, that I believe is set by the 3 degree back ground radiation, there are no authenticated radio transmissions observed. You can then set a limit on the radio signal power that any object in the known universe could transmit either isotropically or beamed & say that there are no civilisations transmitting above these power levels. It does not prove a lack of transmission, but set a limit on the size of the signal that aliens could transmit that we would not detect.

It is not very satisfactory, but is extensively used in physics to for example set the limits on the maxs of the photon, the lifetime of the proton etc. in all such cases one can say if this happens it can not have a magnitude above some experimental detection limit.


Regards,

[1nvest]

Look/listen to the incredibly small perhaps, instead of looking outward.

There's the universe (little 'u' that we can see); The Universe (big 'U') that extends out beyond that - that we wont don't get to see until later; And the multiverse, new smaller universes that our universe spawns, existing for a brief period to us, but that spans a trillion years as viewed within many of those universes. Fireworks night approaching, a ideal time to watch all of those Universes (bonfire fire embers) being created and then fading away, and to wonder if any of those had similar life to as we know it form within them at any time.

The logical conclusion is that within infinity there are only so many unique patterns that can be formed before duplication occurs, the but is that finding those is pretty much impossible by looking outward, more probable if looking inward, but where even if found communication would be impossible/pointless. So why bother other than for interest, we're a small single individual on a big planet that is a small dot in our solar system, that is a small dot in our galaxy, that is a small dot within the Universe that is a small dot within a flat multiverse (collective sum of zero).

[CliffEdge]

Sometimes you just got to leave it to someone else.