1

Physiology & Medicine / Re: H2O2 good for mouthwash?

« on: 17/11/2018 16:23:17 »

Peroxide mouthwashes are widely available. They're rather acidic though, IRC similar to orange juice.

2

New Theories / Re: Reactionless Drives Possible ?

« on: 08/11/2018 02:56:48 »

Nope. They violate both conservation of energy and conservation of momentum. If you could build them, then you have created a potentially infinite power source.

3

Technology / Re: Are heavier-than-air hybrid airships a good idea?

« on: 16/10/2018 16:19:11 »

FWIW the 'flying bum' Airlander has a top speed of 92 miles per hour, so provided the wind isn't as fast as that, it can still make headway. Airships often fly lower in the atmosphere than most aircraft, (well below the jet streams) where there's lower wind speeds.

4

Physiology & Medicine / Re: Can Cataract be Cured without Surgery?

« on: 06/10/2018 03:34:19 »

Most of the advice on 'antioxidants' is bunk. However cataracts is one of the conditions that it might help for:

https://www.allaboutvision.com/nutrition/cataracts.htm

To the extent this is right, you want a diet high in antioxidants, vitamins A, C, E, lutein and zeaxanthin. So, not so much carrots, more Kale. Also you don't want a super high carbohydrate diet; glucose can react with proteins in the eye and can trigger or accelerate cataracts. If you're overweight, lose it, because that will improve your insulin sensitivity.

But no, so far as I know, it can't be reversed, you might be able to halt it though.

5

General Science / Re: What term describes a solid that has melted to become a liquid?

« on: 06/10/2018 03:12:52 »

Yeah, as Bored Chemist already noted, it's just a 'melt':

https://en.wiktionary.org/wiki/melt#Noun

As in snow melt, chocolate melt, cheese melt etc.

6

Physiology & Medicine / Re: Is the shingles vaccine still useful if I've recently had shingles?

« on: 29/09/2018 02:46:46 »

Most likely the symptoms you have are not due to a current shingles attack, but is the nerve damage caused by the attack. Your immune system would likely have rebuilt antibodies to it, but a vaccination wouldn't do any harm. In about 85% of cases the pain goes away within a year.

7

Physiology & Medicine / Re: Would identical twins fool a paternity test?

« on: 29/09/2018 02:38:14 »

I wonder if epigenetics might be employed- presumably the child's epigenetics would match the father's better than the twin's.

8

General Science / Re: Why no other similar energy to electricity?

« on: 26/09/2018 23:41:24 »

The main advantage of electricity is that it's a low entropy, very highly ordered form of energy.

But other forms of secondary energy could potentially work also; compressed air has somewhat similar properties, but it's probably a much more dangerous way to deliver large amounts of energy for things like lighting.

9

Physics, Astronomy & Cosmology / Re: Magnetic force per distance?

« on: 24/09/2018 20:37:50 »

Either a rectangular Halbach array or just alternate N-S-N-S magnets work (alternate magnets are more or less self stable, whereas the Halbach array is constantly trying to push itself apart.)

10

Physics, Astronomy & Cosmology / Re: Magnetic force per distance?

« on: 24/09/2018 01:49:06 »

Are there magnets that they repel so strong when they are extremely close together, so that you can virtually not make them touch each other, but when they are in a distance of few millimeters, there's barely no interaction?

Thanks

Yes, magnets arranged in an opposing checkerboard pattern do that. The smaller the checkerboard squares are, the more short range it is. from a distance you get virtually no force.

11

General Science / Re: If I wear ANY battery watch, in by a weeks time, the battery is dead. Why?

« on: 24/09/2018 01:00:46 »

To be fair to him, the lower carats of gold do corrode somewhat, and even 24 carat gold can rub off and create a black mark, if there's anything abrasive on the skin (some cosmetics do that for example). It would be worth checking the hallmarks.

12

Physics, Astronomy & Cosmology / Re: Is it possible to secure a magnetic particle in a specific position?

« on: 23/09/2018 20:02:37 »

Diamagnetism. It's a weak form of magnetism that most things have to a degree. In a sufficiently strong magnetic field, of the right shape, stuff floats. Like, live frogs. Also, pyrolitic graphite is particularly diamagnetic and you can float it on supermagnets.

Iron doesn't work, because it's highly ferromagnetic, that means that the attraction increases as it approaches a magnet, which is the opposite of what you want.

13

General Science / Re: If I wear ANY battery watch, in by a weeks time, the battery is dead. Why?

« on: 23/09/2018 19:56:45 »

Look, all you have to do is take the watch to a jeweller, get them to fit a new battery. If/when it stops in a week or two, take it back to the jeweller, they will fix it for you, and explain to you why it's happening.

Iron in blood or your body magically stopping watches is not a thing. Sticky bearings or bad batteries, or leaving a trail of sweat across the battery when you fit it will drain it, or a seal on the watch failing and letting in water or sweat, IS a thing. Or if you work with really strong magnets, that can stop them too, but that's rare.

14

Physiology & Medicine / Re: Could we bring back Neanderthals?

« on: 23/09/2018 19:36:26 »

I approve the idea of bringing back Neanderthals. After all, no other species is more endangered than Neanderthals.

15

Physiology & Medicine / Re: Could we bring back Neanderthals?

« on: 23/09/2018 00:58:53 »

It should be possible in theory, sequenceable Neanderthal DNA exists in teeth as well as in live humans. AFAIK it's far beyond the current state of the art to manufacture genetic sequences as long as that and successfully insert them into a human egg, implant and grow to term.

16

Physiology & Medicine / Re: Can viruses become drug resistant?

« on: 22/09/2018 22:27:10 »

Resistance is always possible. It's just a question of how many simultaneous mutations it would take to reach it.

If the number of mutations is more than a very few, then it's not going to happen in the lifetime of the universe. Whereas things that take only a single mutation happen virtually immediately, within days or weeks due to the error rates and rates of reproduction rates of viruses.

17

General Science / Re: If I wear ANY battery watch, in by a weeks time, the battery is dead. Why?

« on: 22/09/2018 01:15:36 »

These battery watches, let me guess, they weren't the best quality???

Otherwise you could have returned them under warrantee, and got a replacement. Good-quality watches with good quality batteries fitted by jewellers don't do that.

18

The Environment / Re: Is there any hope of effective action on climate change?

« on: 20/09/2018 22:59:48 »

Really large scale deployment of biofuels is, with currently available technology, a non starter; their production takes up far too much land. Small scale deployment might work, maybe 10% of current fuel use (enough for airlines). The rest will probably have to electrify.

The technology- and more importantly- costs of the technology are making major strides and are likely to see widespread deployment by about 2025. All the technologies, like batteries, biofuels, solar, wind, electric cars etc. actually look like they are going to interwork really, really well.

There are some worrying areas, like shipping, it may be that a lot of shipping will have to switch to going overland instead. Electrifying ships seems to be beyond the current state of art, unless there's nuclear power involved.

19

Physics, Astronomy & Cosmology / Re: What is the maximum force of the smallest magnet?

« on: 15/09/2018 22:29:28 »

Magnetic monopoles don't exist, and cannot be constructed.

20

Geology, Palaeontology & Archaeology / Re: To what extent can Biblical accounts of Noah's flood be believed?

« on: 15/09/2018 22:14:05 »

You can't really believe it. Noah's ark story is just a retread of one chapter of the Epic of Gilgamesh.