**Ask a monkey a physics question thread**

[chemist]

Is there methane based life on Titan that eats hydrogen?

Dunno.

There is currently no known evidence of extra-terrestrial life. There is a bit of fuzziness there in that amino acids have been found in (I believe) comets and asteroids.

wikipedia "Life on Titan"
If it's there, it's going to be exotic to say the least. We know basically nothing about the origins of life. Our direct evidence only suggests that it happened on Earth (or near enough to Earth and was deposited here).

It would be a huge boon to biology to have another example to study.
Niel DeGrasse Tyson has said that he would be excited just to find DNA anywhere but Earth.

Some researches found a possible cell wall structure which might work.
It's a computer model of a structure with similar properties to a cell wall. It has not been observed in nature (as far as I can tell from the article).

It sounds like this is only one piece of the puzzle. A cell wall is important insofar as it protects the rest of the cell. We still need a model (if not example) of the internal chemistry/biology that makes up the cell.

Going back to an old topic.
"If it's there, it's going to be exotic to say the least."
"Niel DeGrasse Tyson has said that he would be excited just to find DNA anywhere but Earth."

If it is so exotic why would it necessarily have DNA?
Could something exotic without DNA still be considered a life form?

[MadMojoMonkey]

Going back to an old topic.
"If it's there, it's going to be exotic to say the least."
"Niel DeGrasse Tyson has said that he would be excited just to find DNA anywhere but Earth."

If it is so exotic why would it necessarily have DNA?
Could something exotic without DNA still be considered a life form?

The first question answers itself. It would be hugely unlikely for it to have DNA if it isn't something that the universe or periodic table favors. If it could be shown that the DNA-having stuff originated from somewhere else, that's huge. (If it turns out it came from here and contaminated to somewhere else, then that's meh.) If it turns out that there is non-DNA-based life, then that's huge.

The second question is probably better answered by a biologist, but my gut says that if it can argue that it is alive, then it's probably best to not argue back that it isn't.

[chemist]

The first question answers itself. It would be hugely unlikely for it to have DNA if it isn't something that the universe or periodic table favors.

That is what I thought and why I was confused by the Niel DeGrasse Tyson statement which I thought was irrelevant to the original answer. Sure non earth originating DNA is interesting but let's not rule out non DNA exotic life.

if it can argue that it is alive, then it's probably best to not argue back that it isn't.

Good Answer.
Unless it is smaller than us, then we could argue with it.
I'd argue with a little monkey but think twice about arguing with a big Gorilla, (unless it was remotely in an online forum).



I'm glad black holes are so far far away that we can't yet measure their change in gravity as they consume galaxies,
though a little concerned that you show the milky way in your example.

(our great great ... great ... great ...great great grandchildren should definitely have a referendum to leave the milky way before that hole takes over)
Yeah I know you're going to point out the sun will have expired long before that happens.

[MadMojoMonkey]

That is what I thought and why I was confused by the Niel DeGrasse Tyson statement which I thought was irrelevant to the original answer. Sure non earth originating DNA is interesting but let's not rule out non DNA exotic life.

There's probably a tone issue here. He sometimes answers a question in a way that implies, "Not only would that thing you implied excite me, but this other thing which is much less complicated than your thing would excite me."

I'm glad black holes are so far far away that we can't yet measure their change in gravity as they consume galaxies, though a little concerned that you show the milky way in your example.

Don't be. It's highly speculated that Sagittarius A-star is the reason there is a Milky Way in the first place.

Current hypotheses suggest that there is a Super-Massive Black Hole at the center of every galaxy. Unfortunately, it's pretty hard to directly detect a black hole, even an SMBH. They're generally surrounded by a galaxy of stars, whose emissions shield the core of the galaxy from observation.

(our great great ... great ... great ...great great grandchildren should definitely have a referendum to leave the milky way before that hole takes over)
Yeah I know you're going to point out the sun will have expired long before that happens.

Dude. Humanity isn't leaving the Milky Way. Not ever. Not using any kind of physics I can reasonably speculate. The inter-stellar distances within the Milky Way are prohibitively far, even with hypothetical near-light-speed spaceships. The inter-galactic distances are another unimaginable scale. Humans are stuck with our Milky Way, as I understand it.

BUT...

Black holes don't suck up galaxies any more than stars suck up planets or planets suck up moons. The gravitation is the same in all regimes. It's just that a black hole has an event horizon. Bear in mind that the sun has a photosphere, but it's of no real danger to Earth, because Earth's orbit doesn't go "inside" the sun. So long as an object's orbit doesn't go inside the event horizon on its closes approach, there is no a priori reason that it ever will be "taken over" by the black hole.