A cave in Romania that was sealed for 5.5M years
bbc.com
bbc.com
- The cave is called "Movile".
- 3 species of spider, a centipede, 4 species of isopod (the group that includes woodlice), a leech never seen anywhere else in the world, and an unusual-looking insect called a waterscorpion
- Movile's only snail [probably the only snail species] suggested that it has been down there for just over 2 million years.
- Many animals are born without eyes, which would be useless in the dark. Almost all are translucent as they have lost pigment in their skin.
- The cave seems to have no contact with the surface; Chernobyl accident had released lots of radioactive metals, which had found their way into the soils and lakes surrounding Movile Cave. However, a 1996 study found no traces of them inside the cave.
- The ecosystem seems to be supported by chemosynthesis; bacteria oxidise methane, sulphide and ammonia, generating energy and organic matter.
Really cannot win either way. Just have to hope there are other, undiscovered, caves like this around the globe.
Maybe we still have dinosaurs lurking somewhere? Jurassic Park anybody?
I guess it depends how you define "ruined", but it doesn't sound like any species have been lost, or life in there has been interrupted in any significant way.
But the moment we discover them...
Also, the people involved in those missions must have known about the possibility of contamination. Do they take no steps against it?
Edit: a double airlock
Edit - and wore a hair net
How can you still extract energy from a O=C=O molecule without using something like flourine? On the other hand, how does the CO2 get back into the carbon cycle? Do the organisms use an endothermic process to get the carbon back?
And has the 10% oxygen content been there since the cave was opened? Or was this the first mass extinction? While the water does not reach the cave, is there a way for air to make it through? I would expect no oxygen otherwise.
> "The bacteria get all of their carbon from just one source, be it methane or carbon dioxide,"
So I'm guessing the author really wanted to say "the bacteria's ability to fix carbon from methane and carbon dioxide is of particular interest".
I'm guessing that the full cycle is the same as the above-ground cycle of photosynthesis (CO2 + H2O + energy => O2 + food) and respiration (O2 + food => CO2 + H2O), except replacing photosynthesis by chemosynthesis.
12 H2S + 6 CO2 -> C6H12O6 (=carbohydrate) + 6 H2O + 12 S
http://apassionforscience.pbworks.com/f/1364093168/foodv.jpg
Is this supposed to be terrifying? Anyone who woke up at night and walked to the bathroom faced pitch darkness and temperatures of 25 °C!
Regardless, I don't think many city dwellers have ever experienced pitch black.
PS: As a kid I used to spend a lot of time walking around in starlight. I only ever really used a flashlight inside. I moved much closer to a city and light pollution is terrible to the point where there is little need to turn lights on in my apartment unless I want to read something.
Yes that's fucking terrifying.
If you're claustrophobic it might put you off, but if you've done any spelunking, this is nothing at all to write home about.
And it's a linkbait and should be fixed by the mods.
Also on BBC September last year:
http://www.bbc.com/earth/story/20150904-the-bizarre-beasts-l...
BBC reporting is really kind of crappy. 12 people walked on the Moon; 22 people orbited the Moon.
Is BB(26) - BB(25) greater than or less than BB(25)?
In fact I would be willing to bet serious money that BB(n+1)/BB(n) is greater than BB(n) if 3 < n.
(This is, of course, assuming that one assumes that BB(n) is well-defined. That is an interesting point of philosophy given the existence of Turing machines which can't be proven to not halt.)
BB(n) grows faster than any computable function. In order for BB(n+1)/BB(n) > BB(n) to hold, BB(n) merely has to grow faster than a sequence whose new terms are obtained by repeated squaring (like k^2ⁿ). That's computable, indeed primitive recursive, so BB(n) definitely grows dramatically faster than it.
https://en.wikipedia.org/wiki/Primitive_recursive_function
Edit: another way of looking at this is that the Ackermann function grows unbelievably faster than functions that easily satisfy the property you describe, and the Busy Beaver function grows unbelievably faster than the Ackermann function. Somehow putting it this way feels like an understatement, though!
However you have encapsulated the reason why I would be confident of this result. :-)
Do you mean Apollo 13? It had three astronauts on board.
100 people: 0.00000134736% of the earth's population
Seems fairly comparable to me.
"How many people are coming over for dinner tonight?"
"Oh, not too many, just about 2.8070175e-10%"
"Ahh, so one chicken will do"
That said, I suspect it's based on the location and composition of the cave and it's surroundings.
> are. It's not at all obvious why that should be, or how
> the animals survive at all.
Mmmm I think it's the opposite: On more animals using the same static air balloons, less Oxygen will be there.
https://www.youtube.com/watch?v=9tOghHmhQKI
It gets more interesting starting on the third video.
You too?
On another note an well hidden cave like that would be great for preserving man made historical artefacts.
> became roughly the 29th person to enter
This is a bit misleading. It should say only species of snail, not a single snail that's been alive for 2 million years
EDIT: Here's a recent comment from dang (the main HN mod) on the topic of summary comments: https://news.ycombinator.com/item?id=11608134
dang's position is that HN threads are about conversation. That's a weird constraint though, and I doubt takeaways reduce conversation in the first place since there's always going to be a difference to one's own internal summary of the post. Perhaps the conversation aspect should be measured empirically, compare threads w/ takeaways vs without ;)
EDIT: I will also say that HN's main draw to me are the comments that are informative. The meta-analysis is super helpful. Takeaways could be considered at the bottom of the range of meta-analysis, so banning people for takeaways might also reduce informative comments.
I've seen entire threads spawn from a clear misinterpretation of the title alone. Encouraging people to put as little effort as possible into understanding a topic can't possibly improve the quality of the discussion around it.
And that doesn't even consider the likelihood that whomever is creating the summary is consciously or subconsciously applying a bias to controversial articles.
Unfortunately, it does seem like a bit of a zero sum game. Providing a summary of the article will prevent people from reading the article, and people would rather engage entirely with the comments than the article itself.
>> I've seen entire threads spawn from a clear misinterpretation of the title alone
Those who would only read the summary are the same ones who would only read the title when no takeaway is present. Should these people be willing to at least read a summary, I suspect that in the majority of cases the resulting comments are a tad more on point. Barring any serious bias by the author of the summary as you mentioned.
>> If someone is unwilling to be engaged enough to even glance at the linked article, they probably can't provide meaningful or relevant commentary on it
Unfortunately the commentary will come, whether it's based on a title or a summary.
>> The amount of effort it takes to RTFA is practically nil.
I agree... most of the time. Sometimes, articles are far too long for what is being reported. How in the world some authors manage to write 20 pages of drivel to stretch out an article that could be presented in one paragraph is beyond me. If I'm not quite sure whether a certain submission interests me, and the article is extremely lengthy, I appreciate having a summary to look at to decide whether I'm willing to invest 15-45 minutes to RTFA - or whether to close the tab and move on. If even skimming the article becomes too much of a chore, I'd rather just get the important tidbits from a summary and move on - usually without dropping a comment.
Common example: articles on criminals and their court proceedings. I just want the facts pertaining to the case. More often than not, I don't give a rat's ass about the 90% of the article that is dedicated to detailing every moment of the defendant's childhood and the lives of every single family member and acquaintance they've ever had. I'm not interested in a woven tale designed to evoke my sympathies. I really don't care to know their favourite flavour of ice cream. I understand why authors choose to write such articles; namely, to tell the other side of the story and humanize the situation. They often just stretch it out too far for my liking, and a summary saves a lot of time.
Mods see user behavior patterns inverted - you see comments, they see users who make repeated comments of a certain type.
Good mods eventually curtail some of that behavior for valid but hard to deduce reasons.
I'm guessing that in this case, it's been stopped because user behavior shifts, and people use summaries instead of reading the article.
Edit: it's also generally bad form to have meta discussions, it encourages a form of navel gazing which worsens the signal to noise ratio.
There's a bit more context than just "dang bans users who tl;dr".