Depth of Life

freefallin002 · 2012-05-26T03:25:33.543887+00:00

Endoliths are microbes that live inside of rocks, coral, or animal shells. They have been found up to 3.3km deep in the earths crust. They might live deeper, but we haven't drilled that deep.

It gets pretty hot down in the earths crust, and heat tends to prevent microbial growth. Hyperthermophiles (things that live at really hot temperatures) can live at up to 121ºc (at least thats the highest temperature we've found microbes), which would limit the depth of microbes to 4-4.5km below the earth's crust, or 7-7.5km below the ocean floor.

nomdeweb · 2012-05-25T14:27:30.169725+00:00

Stone tools have been in use for 1.7 million years. It wouldn't be hard to bore a simple hole in a wooden tube.

talkingzero · 1 day

Something about this doesn't seem right. Can you at all provide any sources, specifically the bit about increasing pressure on the aortic valve leading to a thicker muscle which is bad?

It seems to me that the logical end to this is that a big thin heart would be a good thing, flexible with big volume. This doesn't at all sound good.

SinglePiece · 1 day

What we perceive as sound is a fluctuation of air pressure in our ear. A pure sine tone has pressure that gradually increases and decreases with regular periodicity.

The pitch is simply the frequency at which the periods of high and low pressure repeat. If you have 1 wave per second, it is a frequency of 1Hz (Middle C is 261.6Hz).

Now within one period (the repeating bit), we can have all sorts of areas of high and low pressure. Here is the waveform of a violin. As you can see, there is an overall repeating pattern (that repeats 4 times in the picture), but within that period is a bunch of fluctuations.

The variations of the fluctuations within a period create the different "sound" or timbre (pronounced tamber). Theres a few nice visual examples on this page that show you the differences. Remember, the high points on the graph are moments of high air pressure in the ear and low points are moments of low pressure in the ear.

frostickle · 4 days

This is all excellent advice. Thanks!

frostickle · 4 days

Oh! I forgot to mention I have a reflector, double sided, silver and gold. And forgive my newbishness, but how does the f-number relate to my distance from the subject?

frostickle · 4 days

A friend asked me to shoot her in her prom dress. I'm a complete amateur who just enjoys taking nice pictures of things when I'm out and about, so I have absolutely no experience with shooting models or anything of the sort. She doesn't expect anything professional, but I'd still like to do my best. I've got a Canon 400D, with the kit 18-55mm f/3.5 lens, as well as a new prime 50mm f/1.8, and an old 50mm f/1.8 from the 1960s. I also have a hotshoe mountable speedlite.

My currently plan is to hit up a nearby beach around dusk, to avoid the harsh light of midday, but also avoid the use of my speedlite as much as possible. Maybe catch some nice sunset shots as well.

Does anyone have any tips for someone completely new to the world of shooting people? Maybe some portfolios or collections of similar pictures (mainly, girls in dresses outdoors with natural lighting)?

daveirl · 8 days

This makes me endlessly sad.

Riiju · 9 days

This is all excellent info. Thanks!

Riiju · 9 days

Do most pathogenic bacteria lyse RBCs? I imagine there would be a variety of targets, depending on the pathogen.

Riiju · 10 days

You sure could. All it takes is a single viable cell to start a colony growing. There are lots of bacteria in your mouth (Harvard says over 6 billion cells). Blowing could dislodge a cell and send it tumbling outwards.

I'm not sure if this is anecdotal or not, but in the lab I work in, it's not uncommon to breath to heavily near some bacteria culture media, and contaminate it.

Unicyclesclearlywin · 10 days

It's spelled 'tyre' in the UK and Australia.

PENISFACEMCVAGINA · 13 days

Just a reminder to commenters here: we should stick to hard science. Not speculation or anecdotes.

attractive_commenter · 13 days

Wikipedia has a good bit on this

edit: hmm... it appears that bit of Wikipedia has no sources. Let's take it with a grain of salt.

sdrawkcabsemanympleh · 15 days

On what are you basing this speculation?

cookie_cutter · 17 days

What part of this is more annoying than beatboxing?

Jayross · 17 days

Here's a nice article on the topic, for general background reading.

glitcher21 · 17 days

While not yet in grad school (or beyond), I intend to stick to the path towards it.

I am on the path because I love science. If I'm going to do a job full-time for the rest of my working life, I better love it. I won't pick another career simply because the one I choose is too hard or too low paying.

Mordred19 · 18 days

Is it that the gaseous elements of air don't absorb much (any) light, so its only gaseous water/water vapour that absorb light? Therefore, at sea level light irradiates most strongly at the wavelength that water absorbs least strongly?

nomaple · 19 days

Hate to be a crashing bore, but this answer is incredibly googleable.

Wikipedia

donaldjohnston · 20 days

Alas, my Y chromosome has rendered my chest as flat as the packing mat.

donaldjohnston · 20 days

I've been frequenting the shop for a long while now. I'll definitely make use of that amassed knowledge. Thanks!

donaldjohnston · 20 days

Thanks! The place I'm at is working with Te Aro in Toronto (I'd recommend their Elevens blend). Unfortunately, I'm the guy to fill in the irregular gaps between various shifts, so I won't really have a regular schedule and get to know the regular customers. I'll definitely put on my 'A'-game smile!

UltravioletLemon · 20 days

A very similar question was asked two days ago. Some interesting responses!

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