As said, you need to throw the current physics (light speed in the fastest moving speed can achieve) into dustbin in order them to travel to earth.

I don't say they can't, just we have to rewrite a lot of physics law currently we have if there is.
Regarding ET. Why must every imagination of ET must have eyes, big head, body or a pair of leg? Ain't it is mimic or human imagination only?

Even on earth we have six leg insect, multileg insect, no leg reptile (snake), eight leg octopus, so many many kind life form, why must everyone think ET should be identical to human kind.
It can be in a lot of form if there is a life out there!

It could be because one told the story, then the rest follow the story. In my humble opinion, it is more a human imagination, big brain because they are clever, small limbs because they are smart until don't need physically muscle.
This ET form/build only emerge in 90's if not mistaken, ancient people never talk about or had any history telling what is ET or how ET looked like.

Why must brain at the head? Can be no brain, but nerve interlink across just like jelly fish. Why must they breath oxygen? it is possible to live on carbon dioxide as well like plant.

The way ET being described, it just means people cannot think out of box and everyone just think it must identical to human kind but just different here and there.

Don't mean there is no ET (I also believe there is in somewhere outer space far far away could be million light year), just in my opinion, it is hard to believe universe is so big and every planetory condition is different and there is potential variety of life form as showed at earth as well already. But somehow ET is similar to human kind? which is something is hard to believe, as it is more like hitting a lottery of this probability at least for my view.

B-2 stealth bomber  looks like a flying saucer as well.