How extremophilic bacteria survive in space for one year | Hacker News Reader

How extremophilic bacteria survive in space for one year

medienportal.univie.ac.at

72 pointshhs27 comments

If we ever have a pathogen like Archaea I will shit my pants. Prions already are able to survive 242F for 15 minutes and caustic chemicals so we already have enough on our plates.

I'm going to pose something that was interesting when the Chief Medical Officer of NASA spoke at my school: bacteria in space will have massive amounts of genetic changes -> bacteria on a Mars mission may become pathogenic to the point where we would not want people who traveled to Mars to come back. He also talked about intracranial hypertension being an issue with people going into space and how to remedy that one. It was fascinating to hear a physician in charge of astronauts talk about what medical challenges needs to be overcome.

Sources: https://en.wikipedia.org/wiki/Archaea https://www.nasa.gov/mission_pages/station/research/news/nan... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5509877/ https://pubmed.ncbi.nlm.nih.gov/26099128/

Most hyperthermophilic archaea die well below many bacterial sporulation temperatures already. Additionally, most hyperthermophilic organisms can't live at body temperature, as that's too low, let alone reproduce AND fight off a host immune system. Prions are a special case and not particularly virulent because they aren't genetically tractable.

But prions are a bit like ice-nine in that they can cause other proteins to become prions.

When you look at the bacteria that generate spores, the only population that is usually affected is neonates; which is why it's advised not to give honey to anyone under the age of 1-2. For spore forming bacteria, they're not prevalent in the environment and their transmission is usually limited.

242 °F ≈ 117 °C

I'd imagine it would have an easier time if it were inside a rock, say. The meteorites we have that originated on Mars apparently took millions of years to get here, though. But those are just the rocks we've found, on the third hand. Intra-system panspermia is an interesting and seemingly credible idea but, as they say, More Research is Required.

There is this theory that speed of light is not symmetrical, that is it may be c/2 in one direction and infinity in the opposite one. Given that, we could perceive that meteorites took millions of years to arrive, but it could be in a instant.

Such a theory is in conflict with more than a century of searches for anisotropies of spacetime. No anisotropies have ever been found, beginning with Michelson's seminal experiment.

What is the opposite direction anyways? Opposite to what? The original message? What if the two transceivers are rotating around the sun on opposite sides? What is one direction at one point in time is now another direction at another point. Is there a difference between bouncing a signal off of a mirror back to yourself and sending a signal which then gets a response from the receiving party? Is my point coming across? Because like, are we talking about direction relative to a receiver or direction relative to some fixed body in space?

You overstate it by calling it a theory. I'm sure you just watched the Veritasium video [1] on this very subject. The point wasn't to claim that space has a preferred direction (which would contradict known physics) but highlighting that there is no way to prove the speed of light is uniform, only that the round trip speed is 'c'.

Second, even if the speed of light is unbounded (or has a much higher bound) in one direction, that doesn't give a free ride for objects with mass to travel any faster than they currently do. It would take an incredible amount of energy to accelerate such rocks to near/above the constant 'c' and then you'd need to explain how it returns to normal asteroid speeds before crashing into Earth.

[1] https://www.youtube.com/watch?v=pTn6Ewhb27k

Thank you! Haha yes I watched Veritasium video...

With synchronized atomic clocks, I could measure one-way speed - at least well enough to tell the difference between c, c/2, and infinity.

Watch the linked video. He goes into that issue.

No, I'm not going to watch the linked video to find out whether he's really answering my question or not. Tell me why I can't synchronize two atomic clocks that are right next to each other, then put one in a car and drive 1000 km away. Tell me why that won't allow me to correlate departure and arrival times well enough to answer the question.

You are being rather demanding, but I'll bite anyway.

When a synchronized clock is accelerated, it will experience time dilation as compared to the stationary clock; they will no longer be synchronized. You might think: ah, I'll just correct for that using relativistic calculations. But you'd be wrong again because Einstein explicitly states that everything in his theory assumes that the speed of light is uniform.

Really, the video does explain all this and more.

What? How did you arrive at that conclusion?

> Intra-system panspermia is an interesting and seemingly credible idea

another interesting idea is that our Sun is not hot enough to produce any elements heavier than iron, meaning that trace elements in you and I are of extra-solar system origin

Panspermia is an idea, that's a fact. Our sun makes helium. It doesn't even make helium that we use - we get our helium from underground deposits filled by radioactive decay.

unsure what your point is

Panspermia isn't widely accepted, but stellar nucleosynthesis/supernovae are generally accepted to be the source of the heavy elements.

I think parent's point is that, to an extremely accurate approximation, none of the elements on Earth come from the Sun. Hence, while it's true that trace elements didn't come from the Sun, it's weird to focus on that because nothing else did either.

EDIT: And it's also weird to tie this to the fact that the Sun won't produce elements heavier than iron through normal (i.e. non-nova) fusion late in its life since that has nothing to do with it.

I would have assumed all of the material in the solar system didn't come from our sun?

Other than what's been blown off the sun as solar wind.

I mean, Earth didn't originate from material from the stella explosion of Sol.

indeed, and humans are a material part of Earth

The sun is a second generation star, that is it formed out of earlier stars who did make those heavier elements.

All of the material in the Solar System - sun and planets - formed from the same original cloud of atoms. This cloud itself included atoms generated by earlier generations of stars. The different elemental composition of the Sun and planets was partly driven by the physics of processes operating as the system matured.

We are stardust, risen like a phoenix from the ashes of giant suns exploded eons ago...

The headline made me think of paypal.

From extremophile to tardigrade to paypal.

https://news.ycombinator.com/item?id=24450828

It's amazing what the human mind is capable of. That or I need to kick my HN addiction.

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