1

General Science / Re: Are there any events that could cause global extinction?

« on: 09/10/2017 06:02:49 »

Why are people so obsessed with "global" extinction/depopulation scenarios?

I'm a optimist person. I think humanity is resilient enough to survive doomsday.

Do you have house insurance? If so you should understand why your question is illogical.

Not sure that’s what tkadm30 meant, s/he used word obsessed.
I have house insurance but I don’t constantly think about it falling, burning down etc. However, I know someone who is obsessed with those possibilities.
The possibility of events beyond their control does seem to cause many people a great deal of illogical worry. I remember reading a letter to a newspaper complaining that a local council had built a nuclear shelter under the local council offices which the writer concluded made that town one to be avoided as it was now a target. I looked at a map of the area and found within a 20 mile radius a military airfield, a commercial airport, a hardened military command centre, and a communications centre. The council offices were unlikely to survive an attack of any one of those more likely targets.

2

Just Chat! / Re: How to end globalization?

« on: 08/10/2017 23:08:21 »

- The death of free markets and fair trade
- The enslavement of humanity into poverty and cheap labor
- The rise of GMO foods and the death of substainable agriculture
- The dictatorship of climate change

The first 3 of these have been problems for a very long time.
Many free markets only exist because of anti-monopoly laws. Look at the history of the East India Company and others.
A substantial war was fought in US because of the 2nd
Selective breeding of plant and animal species (and sometimes human) have been around for a very, very long time.

3

Physics, Astronomy & Cosmology / Re: How is magnet size and shape calculated to provide a given magnetic field?

« on: 27/09/2017 14:03:20 »

Can you answer, to my questions on this forum.

I very much doubt that he has the skills you seek.

This is the key to possible solutions that I want.
link: https://www.thenakedscientists.com/forum/index.php?topic=71465.0

Looking at that link I see a comment:

I am admittedly curious as to what would happen if you constructed a shielded magnet like the type shown in post number 6. Would the magnetic field stop working altogether?

I think Kryptid is right. The magnetic field lines will flow through the shielding material from the enclosed pole and at the open end the field lines will try to take the shortest route to the open pole - the surrounding shielding will act as the opposite pole. You will have made something similar to a horseshoe magnet where one pole (the outer pole) surrounds the inner one, this means the field will not extend out as far as an unshielded pole. However, I think you will need to leave an air gap between the poles otherwise the field extent will be minimal.

4

Plant Sciences, Zoology & Evolution / Re: Do bees die when they sting?

« on: 24/09/2017 15:53:33 »

Suicide implies that the bee deliberately sacrifices itself, but the bee doesn't know it will die when stinging a human. Even if it could learn by observing others it wouldn't get a consistent message. Bees mainly use their stinger to attack invading insects and the stinger doesn't get stuck in their carapace, it only gets stuck in human skin and as they struggle to escape the stinger and venom sac get pulled out - major trauma injury.
If you get strung and can grasp the bee carefully by the wings, it will rotate and the stinger will be released, this even works with the rubber gloves I use for beekeeping. However, do rub the stung area with lavender oil it will relieve the inflammation and hide the attack pheromone that attracts other bees to sting you.

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Physics, Astronomy & Cosmology / Re: Is it possible to make a shield to block a magnetic field?

« on: 24/09/2017 07:19:55 »

As @Bored chemist  says an iron plate will do the job as will sheet steel. You have to make sure that the metal does not saturate, so it will work as long as you aren't using extremely powerful magnets. You also need the shield to extend beyond the length and width of the magnet or you will get leakage around the sides. Best to experiment.

6

The Environment / Re: Will sea levels not rise if sea ice melts?

« on: 22/09/2017 14:59:31 »

I'm going to move this to environment section, because it is an interesting question

7

The Environment / Re: Will sea levels not rise if sea ice melts?

« on: 22/09/2017 14:43:34 »

Your friend is correct for fresh water ice floating in freshwater, but that isn't the case for ice on the earth.
Ice at the North Pole is floating, but that is freshwater ice (mostly + dust etc) floating in seawater. If you do the sums you will find that for freshwater ice in a saltwater tank, when it melts the water level would rise slightly. The other thing to consider is that a lot of the earth's ice is not floating eg, Greenland, Antarctica, Canada, Siberia so that would directly contribute to a sea level rise.

8

New Theories / Re: Is the universe made from one particle?

« on: 19/09/2017 11:42:33 »

Why don't you suck his dick while your at it?

Why don't you go and play somewhere else, tell you what I'll help you do that.
You have been warned recently about abusive remarks and you have preveiously been temporarily banned for the same behaviour. You show no sign of changing and so let's make it permanent. No loss to us.

9

New Theories / Re: Is I.T. E.R. the wrong shape?

« on: 18/09/2017 17:53:20 »

If you read my original post carefully you will see i never mention gravity.

No but in reply you did say:

what shape is the fusion powered Sun?

@evan_au was answering that question in relation to your reply. Just to explain what he is saying, the sun is spherical because of gravity and gravity is also the containment field.

After looking at it in detail I can declare with full confidence that it will NEVER work because of a fundamental flaw in the concept and it should be shut down.

If that is the full extent of your 'detailed' analysis other, deeper thinkers such as @Thebox will run rings round you.
So, do you have a detailed anaysis or not?

10

Physics, Astronomy & Cosmology / Re: What arrangement of magnets produces the greatest magnetic field strength?

« on: 16/09/2017 10:42:42 »

Helo Kryptid
Thanks for your feedback and suggestions. I'll take this answer seriously.
Whether it is just your opinion or the result of your experience. I do not have a measuring instrument.

Still, I will wait for other members of the forum to say their opinion.

You should definitely take Kryptid's feedback seriously. Based on the quality of previous answers  the reply is based on both knowledge and experience rather than opinion.

In addition I would say:
Practical magnets are rarely perfectly smooth or have coatings, this reduces the quality of contact between the magnets and reduces the overall strength of a stack.

The stack should not be higher than the diameter of the magnets, beyond this the strengths do not add together, but start to decrease towards a limiting value. As an example with measurements of 10mm dia x 1mm thick magnets
Number of magnets.             Force
1.                                                 0.5
2.                                                 1.0
3.                                                  1.5
4.                                                  1.9
5.                                                  2.1

It's also worth noting that in a stack of magnets the attraction between the 2 end magnets is often less than that between the end of the stack and the metal object being attracted.


Hope those points help.

11

New Theories / Re: S.O.S. Save the mathematicians

« on: 12/09/2017 16:36:49 »

d2 - d1 would not equal half the distance between circles.

Sorry, I wasn't clear enough. The distance between the circles - the blue line in your diagram - is

It would have to be:

+d1=halfway of the thickness between circles?

Yes, that is also correct. It is the diameter of a circle whose circumference is exactly halfway between the inner and outer circles.
Now I'm doubly impressed. Not only are you using math to correctly describe your ideas, but you are also thinking real maths and making useful conclusions.

12

Marine Science / Re: What is the safest way to snorkel?

« on: 08/09/2017 18:25:38 »

- Most important, get a buddy. Alternate, one dives other stays on surface and watches.
- Get a line cutter, fishing line is near invisible and will be impossible to break.
- Don't hyperventilate, running out of oxygen in the blood doesn't trigger the need to breath feeling, CO2 build up does; so hyperventilating flushes CO2 out of blood and delays need to breath feeling so you can run out of oxygen.
There are lots of other tips, but I'd put those as top 3

13

Physiology & Medicine / Re: At what age does vision become functional?

« on: 17/08/2017 16:50:07 »

Also, we don't know yet at what time exactly vision should have become functional.
 

Vision is present before birth. Although newborns have a very fuzzy view (they can only focus out to 20-30cm) they will look towards lights and movement. They will also blink if there is a sudden bright light.
It will take about a month before they can fix on an object so initially the eyes might appear to wander and they won't follow an object eg toy.


I don't know if stimulation might help, but unless a light is intense it is unlikely to do harm. You might try switching on/off a flashlight just off centre of gaze, you could also try different colours.
When my wife did her paediatrics rotation she used to tell parents not to take too much notice of standard milestones as there is a wide std deviation.
Although you would expect a reaction at 3 weeks there could be a lot of reasons why not including weak eye muscles.
I hope the more detailed examination brings good news.

14

New Theories / Re: Moderator: Can I post a Youtube link to a video on this forum?

« on: 16/08/2017 10:02:52 »

Yes that's fine as long as it is in the public domain or you have copyright.
There is even a button to help you, look below the 'font size' drop down in the tools above the text editing box.

15

Physics, Astronomy & Cosmology / Re: Is the sun in the same spot each year?

« on: 15/08/2017 10:12:50 »

Within practical accuracy, and from year to next, the answer is yes. Over time there are small changes due to shift of the earth's tilt etc. Remember the solar year and calendar year are not the same so leap years make a 1/4 degree shift each year.
If you want to know the path with extreme accuracy and have the instruments to check, there are tables you can use to calculate the apparent position ie allowing for aberration.