1

General Science / Why do trees produce a circular optical illusion when illuminated at night?

« on: 28/02/2015 04:44:15 »

I have noticed in winter when the limbs are bare there is an optical illusion that occurs when one places a tree between oneself and a street lamp.

Whenever a bare tree is backlit the limbs seem to be growing in concentric circles around the light.


A bare tree at night


With the light behind the tree. Had to block the light eith my hand so the camera would expose for the branches and not be washed out by the lamp.

Anyone understand why this occurs?

2

General Science / Why do LED tail lights trail to me and not to the rest of my family?

« on: 08/08/2012 22:29:09 »

The family and I were riding home the other night and I was complaining about how LED lights strobe when I look away from them.  The rest of my family couldn't see it.

What's going on here?


^^^
What my family sees.


^^^
What I see.

It's just LED lights that strobe too.  Incandescent don't.  Some makes of cars are worse than others as well.  Cadillac's SUVs are especially bad. 

The trails are strobes as well, not streaks.  Do LEDs power on and off like fluorescent lights? 

3

Chemistry / How to make Ferric Ammonium Citrate?

« on: 23/06/2012 21:23:50 »

I'm an alternative process photographer.  Meaning I print my photographs with 19th century formulas.
I get great satisfaction from mixing my own forumlas.  I also like to tie my images directly to where they were originally captured.  For instance, the image below was shot on the bank of the Arno river. After I captured the image I went went down to the Arno and collected a gallon of water which I then filtered and used in the development process. I want to take this a step further.   I live on the coast of Georgia (state not country) and there is a goodly amount of iron in the sand.  I can collect it with a strong magnet. 

Can one make ferric ammonium citrate in a home lab?  And if so how would I go about accomplishing it?


This is a VanDyke print.  The formula I used was a 9% solution of ferric ammonium citrate, 1.5% tartaric acid, and 4% silver nitrate.  The water was distilled from the Arno, and then the print was developed in filtered Arno water. 

The above is really simple to do.  Dissolve the required chemicals (which can be purchased from many photography supply houses) to the desired solutions in distilled water, and then mix the three solutions together and one has VanDyke sensitizer.

If I can make my own F.A.C. one of the things I plan on doing is collecting micrometeorites and creating an image that is at least in part made of extraterrestrial iron.  My house has a few rain barrels and they always have a bit of sediment collected in the bottom, mostly bits of leaf and bird dirt, but if one runs a rare earth magnet through it, it always comes up with some ferric material.  Part of that material has to be micrometeorites.

Thank you for reading through my hair brained idea,

--Allen

4

Plant Sciences, Zoology & Evolution / What type of fish could this be?

« on: 07/01/2011 21:45:20 »

I caught this in my pond in the northern part of the State of Georgia.

To me it looks like a bass/crappie (or maybe bream) hybrid.
Anyone have a clue?

5

General Science / How does this illusion make Einstein resemble Marilyn Monroe?

« on: 24/08/2010 16:05:22 »

That's Einsteine right?  Now get up and look at the image from across the room--Marilyn.

How does this optical illusion work?

6

Plant Sciences, Zoology & Evolution / How many leaves are on a tree?

« on: 24/02/2010 01:28:25 »

In front of my house is a 250 year old oak tree.
It can cover the ground six inches deep in the autumn.
While sweeping leaves off of my front porch I started to wonder how many leaves could possibly be on this tree.

I know it will vary by species, but does anyone know how many leaves are on a mature tree of any kind?

7

Technology / Can I charge my mobile phone with a bicycle dynamo?

« on: 04/02/2010 20:19:00 »

I know very little about the black art of electronics.
Could I use the hub dynamo on my bicycle to trickle charge a cell phone battery?

Specifically what I want to do is wire this up to dynamo hub with an on/off switch in between. 

I know nothing about the charge rates of Li batteries, just that this is designed for a 12 volt car and that I have a 6 volt supply.  Is it safe to assume that it will work but take twice as long to charge?

With many thanks,

--Allen

Oh, and this is the hub I have laced to my front wheel.

8

Just Chat! / I found folding money in the wood shed

« on: 31/01/2010 22:51:47 »

Just laying on the ground under the firewood.

What is this now, about 20 quid?

9

General Science / Does magnetism curve space?

« on: 07/01/2010 20:11:58 »

Sorry for the stream of consciousness post.

I was listening to a pod cast that mentioned magnetic monopole news stories during 2009.

Here's the stream of consciousness part--I looked up magnetic monopole on Wiki and then found myself reading about Flux Tubes.  And while trying to wrap my head around understanding whatever a Flux Tube may be I had the thought. 

We live in a flat universe, meaning if one travels in a straight line you will never end up back where you started.  A photon will travel in a straight line forever unless it encounters something massive enough to curve local space.  The same is true of an electron stream unless it encounters a magnetic field.

So here's my question: does a magnet loop space back onto itself, at least for electrons, or is a magnet a black hole for electrons?

10

Just Chat! / Ice skating in Georgia?

« on: 06/01/2010 19:27:44 »

This is in Georgia.
The last time the pond froze was when I was a small child.
I wonder where I can buy some ice skates around here.

11

Just Chat! / The New Photo Thread

« on: 02/01/2010 05:00:00 »

Because I couldn't find the old one.

Here is one from my Christmas present to myself.
Gotta say, I'm impressed with the iPhone's camera.

12

General Science / Why are humans so long lived?

« on: 17/12/2009 13:57:54 »

With the exception of some whales (some of whom have been found with stone harpoons imbedded in their flesh) that may live up to 200 years, I can think of no other mammal that is as long lived as humans, certainly no other terrestrial mammal.

The best theory I can pull off of the top of my head is that being social animals, grandparents must play a significant role in childhood mortality. And I can see how having a set of backup caregivers would be beneficial, more of their descendants  would survive to adulthood hence passing down the traits of longevity to future offspring.  But then would not other social mammals such as the great apes also be as long lived? In captivity, with all the benefits of modern medicine I think a gorilla only lives to be about 45 or so.  So what is special about our physiology that we can pass 100 years--or as in the case of my friend's grandmother, Besse, 113 and counting?

13

Plant Sciences, Zoology & Evolution / Are UK bird feeders causing Incipient Speciation in Blackcaps?

« on: 12/12/2009 23:59:23 »

The split that the researchers observed followed the recent establishment of a migratory divide between southwest- and northwest-migrating blackcap (Sylvia atricapilla) populations in Central Europe after humans began offering food to them in the winter. The two groups began to follow distinct migratory routes — wintering in Spain and the United Kingdom — and faced distinct selective pressures. Under that pressure, the two groups have since become locally adapted ecotypes. (Ecotypes represent the initial step of differentiation among populations of the same species, the researchers explained. If ecotypes continue down that path, they can ultimately become separate species.)


Source

It seems that a sub population of blackcaps are migrating to the UK about ten days before the rest of the population and breeding before the rest wing in from Spain.  The two populations can be distinguished visually about 85% of the time.
The "new" species have rounder wings and smaller beaks.

Pretty neat.

14

General Science / What is the difference between Forging and Casting?

« on: 12/12/2009 20:25:04 »

Just as the title says, when working with metal what is the difference between forging and casting?

Thanks,

--A

15

The Environment / What makes snow wet or dry?

« on: 11/12/2009 18:28:01 »

If it is below freezing it should all be solid.
So what makes some snow wet and heavy and other snows dry and fluffy?

16

General Science / Did Holland just invent the Slig (artificial pork)?

« on: 06/12/2009 02:07:07 »

Some meat-loving researchers in the Netherlands apparently want to make it so that we never run out of ways to clog our digestive systems, and our working on methods to create artificial meat that will be supposedly ready for sale and consumption within the next five years. So far the team has only been able to produce some very unappetizing pork, but they are confident that their initial results will allow them to make improvements to the meat's muscle tissue, which should lead to better outcomes in the future.

"What we have at the moment is rather like wasted muscle tissue. We need to find ways of improving it by training it and stretching it, but we will get there," said Mark Post, professor of physiology at Eindhoven University. "This product will be good for the environment and will reduce animal suffering. If it feels and tastes like meat, people will buy it. You could take the meat from one animal and create the volume of meat previously provided by a million animals."

Source
Google News Search

Mmmm, soggy pork.
Who knew, the Bene Tleilaxu came from Holland.







Definition of Slig

17

General Science / Do you know the length of a Sheppey?

« on: 25/11/2009 04:45:05 »

Sheppey
A measure of distance equal to about 7⁄8 of a mile (1.4 km), defined as the closest distance at which sheep remain picturesque. The Sheppey is the creation of Douglas Adams and John Lloyd, included in The Meaning of Liff, their dictionary of putative meanings for words that are actually just place names. [7] It is named after the Isle of Sheppey in the UK.

Source

I personally think it would be more in the order of 3.5 Smoots.

18

Just Chat! / How observant are you?

« on: 12/11/2009 14:12:35 »

FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC
STUDY COMBINED WITH EXPERIENCE OF YEARS.

Now count aloud the Fs in the above. Count them only once: do not go back and count them again.




















Most people only see three Fs.  There are six.
Why do we miss the others?

19

Just Chat! / Carl Segan and Steven Hawking music video?

« on: 11/11/2009 16:22:44 »

20

Geology, Palaeontology & Archaeology / Will the next sea be The Ethiopiaic, & does it = ?

« on: 05/11/2009 04:07:09 »

In 2005, the earth cracked open in Ethiopia. Two volcanic eruptions shook the desert, and a 35-mile-long rift opened in the land, measuring 20 feet wide in some places. Now a new study adds weight to the argument that the opening of this crack marks the first step in the formation of a new sea that may eventually separate East Africa from the rest of the continent. Says lead researcher Atalay Ayele: “The ocean’s formation is happening slowly, likely to take a few million years. It will stretch from the Afar depression (straddling Ethiopia, Eritrea and Djibouti) down to Mozambique” Source ABC News.


Image Source


And does that mean there are going to be great lava flows like the Siberian Traps before it submerges?