Re: What is the best evidence for or against UFOs?

On Sun, 21 Sep 2025 19:25:55 -0500, Dawn Flood
<[email protected]> wrote:

>On 9/21/2025 12:26 PM, JTEM wrote:
>> On 9/21/25 12:46 PM, Dawn Flood wrote:
>> 
>>> In my opinion, interstellar space travel is, now and forever, a 
>>> technological impossibility.  No matter how advanced a civilization 
>>> becomes, F = ma will still be true, and so, getting from one place to 
>>> another (an interstellar transfer orbit) requires energy, lots of it. 
>>> The bigger the rocket, the more energy, the bigger the rocket, ..., if 
>>> you get my point here.
>>>
>>> This is probably also the reason that human beings will never set foot 
>>> on the planet Mars.
>> 
>> I'm slightly more optimistic than you. I believe Mars is reachable and
>> if we limit ourselves to unmanned tech, even Proxima Centauri &
>> beyond. It's even claimed that if we had maintained the funding on
>> nuclear propulsion we might already be there!
>> 
>> We = unmanned tech
>> 
>> But there's a temporal divide and not just one of distance.
>> 
>> Let's say aliens send a probe to investigate the life on earth.
>> 
>> Great. Life is BILLIONS of years old. So the odds say that it arrived
>> a couple of billion years before we evolved.
>> 
>> Homo, humans, are only like 2.5 million years old, starting with Homo
>> habilis...
>> 
>> So if a probe arrives once every million years, there's been two to
>> three since habilis.
>> 
>> Suddenly our odds of even detecting the debris from an alien probe
>> become ultra slim.
>> 
>
>I would have to take issue even with unmanned space probes, all of which 
>require some energy to function, even if they are sitting in standby 
>mode.  Even the PCBs in the spacecraft will degrade over time, as it 
>would take tens of thousands of years for one to travel the distance to 
>the nearest star (other than our Sun), Proxima Centauri.  When (and if) 
>such a probe arrived, it would be completely dead.
>
>Dawn

Have you taken time dilation into account?