1

Geology, Palaeontology & Archaeology / Re: How to tell if gold in rock is real?

« on: 11/01/2013 21:50:10 »

If it's fools gold (pyrite), you will get a black streak.

Or just a scratch on the inside of your toilet lid.  Streak plates are of very limited value with the harder minerals.

I guess you would know then, that you don't have gold right? The OP was asking for a test for gold.

2

Geology, Palaeontology & Archaeology / Re: How to tell if gold in rock is real?

« on: 08/01/2013 03:53:45 »

I thought Iron Pyrite needed to be fused before becoming magnetic?

Anyway, if you think you have visible gold, take an unglazed tile of ceramic (underside of your toilet lid will work) and scratch the mineral against it. If it's gold, you will get a gold streak. If it's fools gold (pyrite), you will get a black streak. Fool proof!

3

Technology / Re: Can Electrolysis Be Used As a Propulsion Method?

« on: 06/12/2012 19:30:00 »

A quick would seem to indicate that hydrazine hasn't been used as a propellent in the Earth's atmosphere since W.W.II.

A more modern use for hydrazine is as a fuel for the Emergency Power Unit (EPU) on some modern American military aircraft. Nasty stuff and highly toxic.

4

Technology / Re: How do you design for neutron rain?

« on: 30/11/2012 17:05:40 »

If this is true, then why do hand held radiation detectors last so long? I have a GM detector that is very old that still works just fine. I've used several hand held radiation detectors made in the 80's with solid state electronics still functioning normally, even after being through intentional exposure to neutron, gamma, alpha and beta radiation for years.

It must be mostly SMT modern solid state electronics with very high frequency clocks that have the potential to fail? What good is miniaturization of components if we must use redundancy so electronics have a reasonable lifetime?

5

General Science / Re: Physics - Odd effect on metal?

« on: 30/11/2012 16:34:47 »

Are you saying that the effect occured on it's own? One day it was nice and smooth and the next day you saw that? Perhaps expanding and contracting of the aluminum foil during temperature shifts caused it?

Do you have a cat? Are you certain someone/something didn't disturb it?

If it came that way, it may have occured during fabrication or handling.

6

Geek Speak / Re: Can you help me find an old game?

« on: 27/11/2012 23:20:09 »

My guess is Zork or Zork 2 by infocom.

Pawn was a great little text/graphic adventure game. Hitchhikers guide to the galaxy and Leather Goddess of Phobos were also some very good text adventures. Remember lewd mode?

If I remember right, Zork sounds like what you're looking for.

7

Geology, Palaeontology & Archaeology / Re: Help Identify Black Rock w/ Green Flecks

« on: 21/11/2012 16:00:52 »

Is there any chance saamsuun's specimen is a breccia?

If not, what disqualifies it?

8

Physics, Astronomy & Cosmology / Re: Train Tracks - how trains go round corners - Kitchen Science

« on: 20/11/2012 22:42:38 »

Interesting.
There are strict guidelines on how much curvature the track can have, which is likely related to the maximum amount of curvature that the wheels can easily compensate for.

This is certainly true with short bodied ore cars and such.

Modern locomotives, however,  use "trucks" mounted at both ends of the car. Each truck typically has a two sets of wheels/axles fixed in place. The trucks can turn independently with the curvature of the track allowing sharper turns and looser guidlines in track construction.

Edit : The truck is sometimes called a Bogie. Not to be confused with a Boogie.

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General Science / Re: Does putting a sleeping persons hand in warm water really make them pee?

« on: 08/11/2012 02:16:12 »

Ignoring the ethics of experimenting on babies, surely a set of results that said "Babies with hand in water - all found to have wet nappies vs babies with dry hands also all found to have wet nappies too" doesn't really tell you much?
I think the original myth/story is about people old enough to not normally wet the bed. Looks like we still need some volunteers.
(and is it my imagination or is this a rather odd thread?)

LOL...yes, it is an odd thread, but sometimes I think of odd things.  Actually, I was watching an episode of "House", where he (House) put Wilson's hand in a bowl of water, it never showed if it worked or not.  It got me wondering about the science behind it and if it would work on my brother who is horrible and evil and needs to be paid back for numerous hateful pranks!

I hope you report the results of your experiment!

10

General Science / Re: Can maths be funny?

« on: 01/11/2012 18:02:07 »

Now for one a little closer to the ground because the last couple were in a low orbit, if you ask me.

If you divide the circumference of a Jack-o'-lantern by it's diameter, do you get pumpkin pi?

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That CAN'T be true! / Re: Is there any known infection that could create zombies?

« on: 01/11/2012 13:08:23 »

That's good to know.

Note to self : Don't swap spit with zombies!

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That CAN'T be true! / Re: Is there any known infection that could create zombies?

« on: 31/10/2012 19:02:34 »

What better day to resurect this thread back to life than Halloween day?

Okay, so what about the fungus that was discovered to turn ants into zombies? Is there any chance this fungus could evolve to take control over human brains?

Ant zombification begins when an Ophiocordyceps fungus shoots spores onto an insect. The parasitic fungus gradually takes over the ant's brain and directs the insect to a cool, moist location. The fungus then kills the ant, and fruiting bodies erupt from the ant's head and spread more spores.

Link : http://news.nationalgeographic.com/news/2012/05/120504-zombie-ant-fungus-science-environment-rainforest/

Could it be that democrats and republicans are actually two different fungus colonies? Just kidding (I think).

13

Question of the Week / Re: QotW - 12.10.21 - Was pre-historic cave art only done in caves?

« on: 30/10/2012 23:25:33 »

In Colorado, USA, there are hundreds if not thousands of petroglyphs that are not in caves. These petroglyphs are 200 to 14,000 years old and were done by native American Indians.

14

General Science / Re: Do ultra-sonic pest repellers actually work?

« on: 28/10/2012 15:31:45 »

Citronella works very well, in my opinion.

15

Physics, Astronomy & Cosmology / Re: Alien life on Mars?

« on: 26/10/2012 00:09:09 »

However, alien life, even alien microbes could also be very dangerous to grow on Earth as there my not be any immunity anywhere to the life form.  Perhaps one should at least initially restrict alien life to an off-world research station.  The Moon?  Mars?

I couldn't agree more. Even if the original organism is harmless, there may be a chance that the DNA data could get corrupt during transmission and we end up with an angry martian packing a illudium Q-36 explosive space modulator.

16

Physics, Astronomy & Cosmology / Re: Alien life on Mars?

« on: 25/10/2012 21:58:18 »

One of the three tests that were performed to see if life was present on mars, actually had positive results.

"The Labeled Release apparatus brought on the mission worked by scooping up Martian soil and mixing it with water containing nutrients and radioactive carbon atoms. If the soil contained microbes, the life forms would release gases as a result of metabolizing. That Labeled Release test did, in fact, support the theory that there was life on mars, but the other two tests did not."

Apparently, this was enough evidence to justify spending mucho denaro to pursue on the next mission.

Regardless of life on Mars, why not use this technology to increase populations of endangered species or bring extinct species back into existence here on earth? I see no benefit to re-creating "Marvin the Martian" no matter how adorable he is. We are familiar with DNA and RNA on earth, why not start here and bring back some of the creatures that humans are responsible for their extinction. I think that would be the best place to start and would be the right thing to do.

They make it sound like the DNA they find will be analyzed and digitized and sent back to earth like some sort of high tech tweet. If we can store DNA electronically, then we could have an electronic library containing "copies" of every species on earth, including plants and insects as well as animals. You could use the same sort of technology to help inhabit other planets. You can transport a whole zoo on a pen drive which could take up a lot less room on a spacecraft. All you would need is the DNA data and universal recipient cells. Then, just add water, I assume. Some assembly may be required.

17

Physics, Astronomy & Cosmology / Re: Alien life on Mars?

« on: 25/10/2012 15:14:19 »

Let's hope there were no velociraptors or T-rex ever on Mars. The next mission to Mars may have equipment designed to beam DNA back to earth so we can recreate life that once existed there.

John Craig Venter, researcher and entrepreneur, is working to develop a machine that can sequence DNA found on Mars and then “beam” it back to earth. Venter’s goal is to send a “biological teleporter” to Mars, collect Martian DNA, and then recreate Martian life from it.

Link :
http://www2.electronicproducts.com/Create_a_Martian-article-FANE_create_martian_Oct2012-html.aspx

This doesn't make a lot of sense to me when we have several species here on earth that are near the brink of extinction that we could be trying to bring back instead of alien life forms from another planet. Where are our priorities?

So, if we recreate intellegent life from Mars, I think we would have just created a huge problem for ourselves. What if  it turns out to be wicked deadly and able to self reproduce. Our bleeding hearts will fight to keep it alive so it can destroy us all?

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Geology, Palaeontology & Archaeology / Re: WHAT IS THIS WHITE ROCK PLEASE?

« on: 23/10/2012 19:25:30 »

My monitor is giving me problems today, but it looks like banded agate or chalcedony as mentioned before.

19

The Environment / Re: Ideas for population control?

« on: 17/10/2012 23:54:24 »

Andriod Sex Bots /  Media would be a powerful combination for effective population control ..

If we had robots that were "waay better in the sack" compared to any human, coupled with a Media Blitzkrieg Bombardment of notions in support of human to android contact. Humans would eventually fore-go human on human contact in lieu of the  " way more awesomer" human to android contact.

If these robots were better, easier, cheaper and mass produced for everyone, population control would be more effective.

If we stopped fkn each other and started fkn androids, the chances of having a baby would be eliminated. Within a generation or two after implementing this type of paradigm we would notice considerable or drastic population reduction.

Feel free to check out a polka song I wrote about Robot sex bots on facebook
https://www.facebook.com/note.php?note_id=457622168484

Robosexual relationships? I like it.

It slices, it dices, it will clean your house, polish your horn, and you can turn it off during the super bowl. But don't get it mad or it will run home to it's motherboard.

20

Physiology & Medicine / Re: Can clay absorb a dangerous level of radiation?

« on: 17/10/2012 21:22:30 »

There's not enough information to answer the question.

(Incidentally, do you mean CPM?)

I agree.

CPM does not describe the activity or radioactive exposure from a source.

In order to calculate the activity, you need to know the efficiency of the detector for a particular isotope, as well as background counts and source counts.

Let's say, for example, your detector has an efficiency of 12% towards Cs-137. Let's also say that the background counts (without the source) is 60 CPM and counts with a Cs-137 source is 150 CPM.

First, convert CPM to CPS
60 CPM / 60 sec = 1 CPS
150 CPM / 60 sec = 2.5 CPS

Activity (nCi) = (Source CPS - Background CPS)/((efficiency/100) *37)
Activity (nCi) = (2.5 - 1)/((12/100)*37)
Activity (nCi) = 1.5/4.44
Activity (nCi) = .338 nCi

Back to the clay :

Measureing and calculating the activity of Bentonite seems difficult to me since K-bentonite contains Potassium which is radioactive and also absorbs radiation from other isotopes. If you didn't know what isotope was the source of the radiation absorbed by the clay, it would not be possible to calculate the activity with a CPM instrument would it? Conversly, if you knew, for example, that the isotope that produced the radiation absorbed by the clay was Cs-137, then could it be possible to calculate the activity of the clay with a CPM instrument or does the mixed isotopes confound the whole process? I'm Not sure how you would go about calculating the activity or exposure from the clay. I think you would need to use an energy compensated survey meter, yes?

By the way, calculating detector efficiency is easy if you have a source of known activity.

The following formula assumes that a 2pi geomotry is used for source placement (point source directly on the detector)

Det Efficiency (%) = ((source CPS - Background CPS)/((37 x activity of known source in nCi)/2) x 100

Let's say, for example, we have a 9.253 nCi Cs-137 source and we know that background counts are 120 CPS and counts from the Cs-137 is 150 CPS with the source directly on the detector.

Det Efficiency = 150-120/((37*9.253)/2)x100

Det Efficiency = 17.525% for Cs-137

If I made error, please set me straight as I'm still learning.

Edit : I didn't see SeanB's post about the clay trapping the radiation that it absorbs, until after posting this, so please disregard my questions about the clay (above).