1

Physics, Astronomy & Cosmology / Re: What would a cold neutron star look like?

« on: 14/08/2018 23:20:42 »

create geometries very unlike such oxides at standard conditions

I agree that there will be crystal structures and molecules that would never be stable on Earth.

One unique thing that we don't have to worry about on Earth is that the gravitational potential energy on the surface of a neutron star is greater than the strength of mere chemical bonds. So elements would be sorted vertically by density. Chemical bonds would only be possible between atoms of very similar density.

The lightest element is hydrogen, and so it would be in the outer layer. Under these pressures hydrogen would probably form a metallic state, possibly superconducting?

A more speculative distorting factor is that the tidal forces and time dilation effects on the surface of a neutron star may be enough to distort the form of the electron's wave equation so that it takes on different forms than we have on Earth. What this would do to the interaction between light and matter is beyond me!

2

Technology / Re: How will the Parker Solar probe (sun grazer) communicate its data?

« on: 12/08/2018 22:00:19 »

Although the Parker Solar Probe comes very close to the Sun (at perihelion), it spends most of its time far from the Sun (aphelion is at the same distance as Venus).

So for the week or two when it is closest to the Sun, electromagnetic interference from the Sun will prevent radiotelescopes on Earth from receiving data from the space probe. It must be oriented so that the heat shield protects it from the Sun.

Just as Venus is often invisible from Earth because it is behind the Sun (but far from the Sun), the Parker probe will often be out of communication with the Earth, so it has to be very autonomous.

However, for most of its orbit, it will be separated far enough from the Sun in the sky that radiotelescopes on Earth can communicate with it to download the scientific data and upload new instructions. The probe has a 0.6m steerable parabolic dish. The only direction it can't point is within 14° of the Sun's center, as that direction is obstructed by the solar shield.

See: http://parkersolarprobe.jhuapl.edu/index.php#spacecraft
https://directory.eoportal.org/web/eoportal/satellite-missions/p/psp
https://en.wikipedia.org/wiki/Parker_Solar_Probe

3

Chemistry / Re: How to calculate the maximum charge of an atom or a molecule?

« on: 10/08/2018 13:07:57 »

How to calculate the maximum charge of an atom or a molecule?

I think there may be several concepts mixed up here...

Charge of an Atom (Dissolved Ions/Ionic Solids):
It will help if you look at a periodic table while reading this, for example the one here:
https://en.wikipedia.org/wiki/Electronegativity#Electronegativities_of_the_elements
- The intense red elements (eg Fluorene, F near top right) will strongly grab an electron off another atom
- The lightest yellow elements (eg Cesium, Cs near bottom left) will easily donate an electron to any other nearby atom
- Most elements are somewhere in-between
- If you put together elements that are far apart on the electronegativity scale, they will completely transfer an electron (or more) between the atoms, and both atoms will become charged ions.
- The grey noble elements on the top right (eg Helium, He) do not easily donate electrons or take on extra electrons.
- The number of electrons an atom is likely to accept or give away is determined by the distance to the nearest noble gas, which has a full outer shell of electrons.

If we take as an an example table salt, which is mostly Sodium Chloride
- Sodium is in group 1, and easily gives up one electron (the nearest noble gas is Neon, distance = -1)
- Chlorine is in group 17, and easily takes on one extra electron (the nearest noble gas is Argon, distance = +1)
- At room temperature salt forms solid crystals of Sodium Chloride Na⁺Cl^-
- When dissolved in water, they separate to form Na⁺ and Cl^- ions, and it conducts electricity
- When molten, the Na⁺ and Cl^- ions can move, and it conducts electricity

Most metallic atoms easily lose an electron (or two; sometimes 3), forming a positive ion:
- Atoms in the left-hand column (Group 1) easily give up 1 electron. Common examples are Sodium (Na) and Potassium (K)
- Atoms in the next column to the right (Group 2) easily give up 2 electrons. Common examples are Calcium (Ca) and Magnesium (Mg)
- Under some chemical conditions, atoms in Group 13 can give up 3 electrons, eg Aluminium (Al)
- Some of the atoms in between (like Iron, Fe) can give up 2 or 3 electrons, depending on the chemical conditions.

Many non-metallic atoms easily take on an extra electron (sometimes 2 or 3).
- Atoms in Group 17 (eg Chlorine & Iodine) easily take on 1 extra electron
- Atoms in Group 16 (eg Oxygen & Sulphur) easily take on 2 electrons
- Under some chemical conditions, atoms in Group 15 will take on 3 electrons

When dissolved in water, these individual atoms with an electric charge form ions, and will conduct electricity.

Charge of a Molecule:Some molecules containing the atoms mentioned above can form chemical groups which a charge, for example sulphuric acid (H₂SO₄) contains sulphur, and when dissolved in water, the SO₄ ion has a charge of -2.

In a pure element (eg pure Sodium or pure chlorine), all the atoms have the same electronegativity, so they can't give up or take on an extra electron, so they are electrically neutral.

Most stable, complex molecules (like organic molecules) are formed of a mix of elements which share electrons, ie they never completely giving them to another atom, nor completely take them away from the other element.
See: https://en.wikipedia.org/wiki/Covalent_bond

These covalent molecules are overall close to electrically neutral, although there are organic acids that can give up a hydrogen ion to take on an overall negative charge. And some parts of the molecule might have a slightly more positive or negative charge, which can help proteins fold into the right shape.

Ionised Atoms: Above I talked about atoms which easily give up or take on a few electrons, becoming more like the noble elements in Group 18.
- However, if you expose the atoms to extreme temperatures (eg in the Sun's corona), you can rip off extra electrons.
- Similarly, if you subject atoms to an extreme electrical discharge, you can make them give up or take on a larger or smaller number of electrons.
But these unusual charges don't persist at room temperature in our homes.

If you subject a molecule to extreme temperatures or extreme electrical discharge, it will usually tear the molecule apart, right down to ionised atoms.

Mass Spectrometer:This scientific instrument subjects molecules to a controlled electrical discharge, which applies a small charge to the whole molecule, or breaks down the molecule into some smaller components, each with an electrical charge.
It is able to provide an indication of the chemical composition of an unknown substance by measuring the charge to weight ratio of the pieces.
See: https://en.wikipedia.org/wiki/Mass_spectrometry

Oops! overlap with chiralSPO!

4

Plant Sciences, Zoology & Evolution / Re: Why is natural selection so much slower than human-led selection?

« on: 06/08/2018 12:16:56 »

Associating the word prediction and the word lottery like you do can thus be misleading.

Another way of looking at it is that a species with a lot of genetic diversity has bought a lot of tickets in the future, which often looks like a lottery to us.
That genetic diversity increases the chance that they will hold a winning ticket (or at least a minor prize).

mind may produce randomness the way mutations do

In the young mind, neurons are connected randomly to other neurons.
However, as each critical phase of development occurs, connections that don't produce a significant correlation get pruned, leaving a much smaller set of neural connections.

Effectively, a process of "survival of the fittest" determines which neural connections will be retained and which will be lost, based on the environmental exposure leading up to this pruning phase.
If I understand the mechanism, this pruned set of connections then provides the neural inputs to the pruning of the next level of neurons, at the next stage of development.

By this mechanism, an infant becomes adjusted to their environment, even if that environment is quite different from the environment in which their parents grew up.

See: https://en.wikipedia.org/wiki/Synaptic_pruning

5

New Theories / Re: Super Nova ?

« on: 05/08/2018 11:55:48 »

If you want to hear some impressive science knowledge, answering questions without notice, listen to:
- http://www.abc.net.au/triplej/dr-karl/
- http://www.capetalk.co.za/podcasts/115/the-naked-scientist/78148/naked-scientist-dr-chris-smith

I have the luxury of checking my vague recollections on Wikipedia before I post them.

6

New Theories / Re: Super Nova ?

« on: 05/08/2018 04:11:26 »

I didn't have time to watch both videos all the way through, but:
- The first video is about Betelgeuse, a red supergiant star that will probably go supernova in the next million years (and may even have gone supernova already - but we don't know it yet!). Because it's only 700 light-years from Earth, it would be brighter than the full Moon. A much closer supernova could damage life on Earth.
- The second video is about supermassive black holes at the center of galaxies; it is not about supernovae. The nearest supermassive black hole is about 25,000 light years away, and is fairly quiet at present, so this is likely to pose less of a risk in the near future than Betelgeuse (or pollution, which is even closer).

Astronomers are always on the watch for new supernovas, as it tells much about:
- What sorts of stars can go supernova, and at what stage of their lives (this has only recently become feasible to model on our very largest supercomputers, at immense cost)
- Understanding why there are far fewer visible supernovas in our galaxy than theory predicts
- What is the brightness of different types of supernova
- Imaging a supernova using neutrinos
- Refining the distance to distant galaxies
- Measuring Dark Energy
- Supernovas can be discovered by amateur astronomers, giving them their 15 minutes of fame.
- Close supernovas are visible to the naked eye, which is of interest to the general public

Some specialist telescopes scan the night sky on a daily basis, looking for supernovas in other galaxies.
https://en.wikipedia.org/wiki/All_Sky_Automated_Survey_for_SuperNovae

7

Physics, Astronomy & Cosmology / Re: How fast would the earth spin if the moon was closer?

« on: 03/08/2018 23:20:09 »

Using the Moon to dig a 1,000km-deep trench around the Earth would also cause the Moon to break up...

8

Plant Sciences, Zoology & Evolution / Re: Why is natural selection so much slower than human-led selection?

« on: 02/08/2018 22:23:28 »

Why is natural selection so much slower than human-led selection?

Natural selection is a somewhat random process, which means that a beneficial mutation spreads very slowly through a wild population (or may get snuffed out in the first generation).

There is discussion at present about a "gene drive" which will cause a human-made mutation spread exponentially through a wild population. It ensures that more than 50% of the progeny have the gene drive (ie it doesn't obey Mendel's "laws" of inheritance).

Since this could have major impacts on the world's ecology, the inventors have requested a vigorous debate before anyone releases this in the field.

So to prevent the spread of malaria, it is possible to have a gene drive that wipes out all mosquitoes, but this would have unknowable impacts on bird, fish, amphibian and bat populations, plant fertilisation, etc etc.
- Alternatively, it is possible to have a gene drive which leaves behind healthy, blood-sucking mosquitoes, but which carry a gene variant that stops the malaria parasite from infecting them (a gene taken from a mosquito species that does not spread malaria).

Whether members of the public would accept being bitten by a genetically-engineered mosquito is another question; they may be afraid of being exiled as a mutant super-hero....

See: https://en.wikipedia.org/wiki/Gene_drive

9

Physiology & Medicine / Is Toxo-enhanced business acumen all in the mind?

« on: 01/08/2018 23:14:36 »

This week's Naked Scientists podcast covered a paper suggesting that exposure to the Toxoplasmosis parasite is associated with a more entrepreneurial outlook on life, and an increased likelihood to undertake business studies.
https://www.businessinsider.com.au/parasite-in-cat-poop-linked-to-entrepreneurial-behavior-2018-7?r=US&IR=T

Previous studies have shown that "Toxo" infection is associated with more risk-taking behavior (eg increased motor vehicle accidents).
- Is it possible that the association shown in self-reported surveys represents risk-taking behavior in a survey?
- Can we get some more objective measures of whether Toxo is associated with greater success, or is it all in the mind?

For example, in the study that showed a link between Toxo exposure and motor-vehicle accidents, did the Toxo-enhanced drivers rate themselves as better drivers than the non-Toxo drivers who had fewer accidents?
See: https://en.wikipedia.org/wiki/Toxoplasmosis#Mental_health

PS: The story should probably have mentioned the usual warning against pregnant women carrying out the cat tray, as Toxo can kill or maim the unborn baby.
See: https://en.wikipedia.org/wiki/Toxoplasmosis#Pregnancy_precautions

10

New Theories / Re: I have refuted the atomic model

« on: 30/07/2018 10:48:37 »

Only if (electrons) are robots and instructed with some kind of intelligence.

Another hypothesis is that all electrons are almost identical and mindless.
- They "fill up" the available energy levels in an atom by falling into the lowest available energy level (like a grain of sand in an hourglass)
- The preferred number of electrons is determined by the charge on the nucleus
- There is an equation that defines how many electrons can go into each level in an atom
- The Schrödinger equation which describes these levels is very compact: It easily fits on one line.
- It takes a very complex equation to describe intelligent behavior, so I suggest that electrons are not behaving intelligently

See: https://en.wikipedia.org/wiki/Schr%C3%B6dinger_equation

11

Physiology & Medicine / Re: Why Are Piggys Organs Like Human Organs ?

« on: 29/07/2018 23:19:05 »

The chief concern seems to be that Porcine viruses could become endemic in the human germ line

Another potential risk is that porcine viruses could become "acclimatized" to the human body by first growing in immune-suppressed patients, and then they might become transmissible to other humans who aren't immune-suppressed.

Yet another Zoonotic disease for which humans have no previous exposure could become a problem epidemic.
Probability: Low (for small numbers of patients), but impact could be high.
With larger numbers of patients, the probability becomes higher.
https://en.wikipedia.org/wiki/Zoonosis

12

Physiology & Medicine / Re: Why Are Piggys Organs Like Human Organs ?

« on: 29/07/2018 09:22:52 »

Why Are Piggys Organs Like Human Organs ?

Adult pigs have a similar body mass to adult humans, and that means their hearts and other organs are a similar size and have to handle a similar flow of fluids. That makes them suitable as organ donors.

One of the things that has been holding back this field is that there are a number of viruses latent in pig DNA, which might be dangerous to an immune-suppressed human transplant patient.

Some genetic researchers are working to remove these pig viruses from the pig DNA, so that they are a safer source of donor organs.
https://en.wikipedia.org/wiki/Endogenous_retrovirus#Porcine_endogenous_retrovirus

13

Just Chat! / Re: I just got the first real user in my neurosecurity forum! What should I do next?

« on: 28/07/2018 23:45:25 »

What should I do next?

You must do nothing and say nothing.

You have identified a vulnerability in this person's neuro-security, and anything you say or do will exploit this neuro-vulnerability, and represent a violation of this person's neuro-security. This is explicitly contrary to the neuro-ideology of your neuro-security website.

Unless this person has explicitly consented to such neuro-exploitation, anything you say or do will be a violation of the European laws about the use of the internet to invade the neuro-privacy of individuals. Even knowing this person's email address represents private information which penetrates this person's neuro-barriers, and must be protected at all costs.

...and I see another potential neuro-victim signed up while I was typing this....

14

General Science / Re: Is zero an even number, odd number, or neither?

« on: 25/07/2018 12:22:29 »

The idea of zero being divided by anything else is a strange one when contemplated.

What if you had 3 people who agree to cooperate on some work, and agree to split the profits equally.

They are paid $1000, but the materials cost $1000, leaving $0 profit.
In this context, it makes perfect sense to divide $0 three ways, and $0/3=$0.

15

General Science / Re: Could pesticides be linked to allergy rates?

« on: 23/07/2018 11:02:40 »

There is some evidence to suggest that the recent rapid increase in allergies is partially due to increased use of antihelmintics (poisons which kill intestinal worms).

These worms want to have a long and happy relationship with us (even if the benefits are rather one-sided). So they damp down the human immune system, including the digestive tract, asthma and allergies.

With frequent use of de-worming tablets, "Western" societies now have very low exposure to these calming influences on our immune systems, contributing to the explosion of auto-immune diseases. Some people with auto-immune diseases have found that they can control the symptoms by intentionally infecting themselves with intestinal parasites.

So in this cases, excessive use of pesticides has contributed to an increase in allergies (including auto-immune diseases).

See: https://en.wikipedia.org/wiki/Effects_of_parasitic_worms_on_the_immune_system

16

Physics, Astronomy & Cosmology / Re: What will happen when these two stars collide in 2022?

« on: 22/07/2018 05:45:50 »

If KIC 9832227 follows the pattern of V1309 Scorpii, we can expect the merger to occur in several phases:

Before Merger:
- Outgassing: There is a very small amount of gas being flung out of the binary pair system, not enough to produce a visible disk.
- Spectrum: The spectrum shows two sets of spectral lines (one from each star) - when one star is moving towards us, the other is moving away, and then the roles reverse.
- Brightness: Over the orbital period (currently under 12 hours), there are two light peaks, when both stars are visible to us. But at some points in the orbit, the smaller star obscures part of the larger star, and at other points the larger star obscures most of the small star, producing two brightness dips.

Leadup To Merger
- Outgassing: Increasing amounts of gas are flung out of the binary star system, forming a visible disk. The disk envelopes the smaller star. The disk cools rapidly, so is "redder" than the parent stars.
- Spectrum: The smaller star is embedded in the disk, so it no longer shows as a separate set of spectral lines. But the larger star protrudes from the disk, providing spectral lines which are distinct from the spectral lines of the disk.
- Brightness: Light emission from the growing, glowing disk causes brightness to increase more than exponentially. Because the smaller star is buried in the disk, there is no longer the double-humped light curve.

During Merger
- Outgassing: Huge amounts of hot gas spray into space
- Spectrum: The hot gas dominates the spectrum
- Brightness: Brightness reaches a significant peak

During Merger
- Outgassing: Outgassing slows and stops.
- Spectrum: The hot gas dominates the spectrum
- Brightness: The gas disk cools over a period of months, with brightness decaying exponentially. Eventually, the new, disturbed star becomes visible.

What kind  of elements will be created in that meeting?

Unlike the Sun, the larger star will be able to produce elements heavier than helium.
When the two stars merge, it will be even more massive and able to produce even heavier elements (up towards iron) as the star burns all its fuel.

I expect that it won't produce any particularly novel elements - just the sort of elements you expect from a more massive star.

The main question is whether the larger star is disturbed enough to go into a supernova in the short term, instead of waiting for it to exhaust all its fuel.

See: https://en.wikipedia.org/wiki/KIC_9832227

17

Technology / Re: How do batteries work?

« on: 22/07/2018 03:57:06 »

Still no one has explained what happens exactly.

I think Wikipedia has done a pretty good job of explaining it.
But you find Wikipedia too difficult.
See: https://en.wikipedia.org/wiki/Electric_battery

So you have two metals that one has tendency to release its electrons and the other to grab electrons, but both are neutrally charged, right? How do we take advantage of this to make batteries work?

Maybe we should go back to the original observation of battery action with Luigi Galvani...

According to the traditional story, Galvani was presenting a dissection of a frog to an audience...
- The frog was resting on a zinc table, and a metal scalpel was being used.
- At some point in the dissection, the scalpel was put down on the zinc table, with the blade resting on the frog's leg, on the sciatic nerve.
- This caused the frog leg to twitch, even though the frog was dead.
- This led to the discovery of "animal electricity", and later, the battery (when they discovered that the animals were not necessary)

As you say, here we have have two pieces of metal that by themselves are electrically neutral.
- of these two metals, one has tendency to release its electrons and the other to grab electrons
- As soon as the two pieces of metal are put in electrical contact (in a wet environment), electrons rush from one metal to the other, making them electrically charged.
- But by itself, no electrical current will flow, even though there is a potential difference between them
- If you now complete the circuit (by touching both pieces of metal on a frog's leg, for example), an electric current will flow through the external circuit (passing through the sciatic nerve and causing the frog leg to twitch, in this case).

See: https://en.wikipedia.org/wiki/Luigi_Galvani#Early_life

18

General Science / Re: Is zero an even number, odd number, or neither?

« on: 22/07/2018 03:40:30 »

0/1, and the related infinity

I think you mean "1/0, and the related infinity".

A lot of mathematicians survived over the centuries without accepting that zero was a real number, even if they accepted "0" as a placeholder in Indian/Arabic numerals.

19

General Science / Re: How does soap make us more clean than just water does?

« on: 22/07/2018 03:35:54 »

I know soap removes oil and that soap is hydrophobic.

The hydrophobic part is only half of the story.

In fact, soap has a hydrophobic (water-avoiding/non-polar) end, and a hydrophilic (water-loving/polar) end.
- Oils tend to be water-avoiding.

This means that the soap grabs the oils (hydrophobic end), and also grabs the water (hydrophilic end), and gets them together, so that water is able to break down oil films and wash away the oils, instead of the oils staying stubbornly in place.

Soap will help water wash away some bacteria too, but the main thing here is to scrub under running water.
See: https://en.wikipedia.org/wiki/Detergent

In reality, natural oils are helpful to our skin and hair, and overuse of soap and detergents can remove these helpful oils.

But in a hospital setting, presence of drug-resistant bacteria (eg Staphylococcus aureus) and fungi (eg Candida auris) around people with weakened immune systems means that you can't have too much hand-washing.

20

Physics, Astronomy & Cosmology / Re: What will happen when these two stars collide in 2022?

« on: 21/07/2018 03:24:40 »

Looking at the previously best-studied example of a "red nova" (V1309 Scorpii), it increased in brightness by 10 (astronomical) magnitudes, or by about a factor of 10,000 at the time of merger. The brightness then declined over a period of a month or so.

Similar behavior would take KIC 9832227 from magnitude 12 to magnitude 2, which would be very visible to the naked eye (provided it didn't happen while Earth was on the other side of the Sun).

The decreasing distance is due to tidal effects transferring angular momentum from the smaller star to the atmosphere of the larger star (gravitational waves have significant effects only on compact objects like neutron stars and black holes).
See: https://en.wikipedia.org/wiki/V1309_Scorpii
See the light curve at: http://inspirehep.net/record/1242804/plots
(Second graph on the page; the horizontal axis tick marks represent 10 days each.)