1

New Theories / Can a photon escape from inside the event horizon of two black holes?

« on: 16/07/2022 21:47:41 »

Picture a situation where two black holes are moving in opposite directions at just a fraction under the speed of light. Their event horizons are length contracted so much that they practically become discs rather than spheres. The two black holes pass each other in such a way that at the point of closest approach the edges of the two discs pass through each other. (Picture one moving towards you and the other moving away, and imagine them side by side as they pass each other - both should be deflected sideways by each other's pull, and the amount of that deflection will be related to how fast they're moving.) Now, if we have a photon moving perpendicular to that action (you should visualise this as moving straight upwards) such that it passes through the edge of both discs exactly at the moment when they pass through each other, it won't be directed towards either black hole and should just continue on up the same path as it was on before, exiting both event horizons simultaneously.

2

Physiology & Medicine / Is anyone here involved in studying nattokinase?

« on: 16/07/2022 21:13:03 »

If anyone has been working on it, I'd like to see numbers for how nattokinase measures up against warfarin and aspirin for blood thinning. Over the last ten months I've had a series of blood clots hit my lungs which doctors have been unwilling to investigate because they weren't sufficiently close to lethal at a time when the queue for scans was a mile long due to the Covid crisis with priority going to those who are taken in unconscious. The queues are still a mile long, and having had another blood clot hit my lung after a gap of seven months, I'm now taking 20,000 units of nattokinase a day (plus 150mg of aspirin). The problem with nattokinase though is the unreliable delivery as it can get stuck in the stomach for widely varying lengths of time where it is not absorbed, so I want to do more of the work with aspirin, but I don't know how much to adjust one in response to adjusting the other.

3

New Theories / Does this experiment disprove relativity?

« on: 22/05/2021 06:41:42 »

Mod edit: Topic split off Can you measure the one way speed of light without synchronised clocks?
https://www.thenakedscientists.com/forum/index.php?topic=82170

Imagine lots of clocks being made immediately after the big bang which are then separated from each other by the expansion of space, leaving us with a universe full of clocks rather than galaxies, but all spread out through space evenly. We could take any pair of these clocks and accelerate them towards each other with equal force, and when they meet up they would both agree about what the time is. But that would only apply if the clocks were all at rest in the expanding space. What happens if they were all moving through space at high speed in the same direction? Well, in some cases when you bring two of these clocks together, you’ll be accelerating one and decelerating the other, so they will not agree on the time when they meet up. If those clocks existed, this would provide us with a means to pin down the absolute speeds of motion of the clocks, and once we have those, measuring the one-way speed of light relative to a host of different types of apparatus (and knowing that you're getting the correct answer) becomes trivial..

(We can’t go back to the big bang to place lots of clocks there to do that experiment for real, but space is still expanding, and it’s doing that here. This means that we should be able to carry out essentially the same experiment right here and now, as I set out recently elsewhere.)

If you’re having difficulty understanding why the clocks in some cases would have to go out of sync when you bring them together, this must happen in order to conform to the rules of the twins paradox. Imagine that when the clocks are created right back at the time of the big bang, they all send out watches in two opposite directions. Set A of these watches are all moving in the same direction as each other and at the same speed, while set B of watches were sent out at the same speed but in the opposite direction. Let’s suppose that the clocks are stationary and the watches are moving. If a set A watch meets a set B watch, they will agree with each other about the time, but if any watch meets a clock, the time on the watch will lag behind the time on the clock due to its speed of movement through space. How can I prove that? Well, in a case where a set-A watch passes a clock, then passes a set-B watch later on, and then the set-B watch passes the clock later still, we have the twins paradox experiment being carried out by those three timers. We could have scenarios where the clocks and set-A watches are both ticking at the same rate (which means the clocks aren’t at rest), but the set-B watches would have to be ticking slower than that in order to produce the required result for the twins paradox. Once you understand the necessity for that to happen, you should then be able to see that when clocks/watches pass each other, the amount by which they disagree on the time provides information about their absolute speeds of motion through space. Relativity is cracked wide open by this.

4

Radio Show & Podcast Feedback / 5 Live Science reviewed on Radio 4

« on: 22/05/2021 05:51:32 »

Radio 4's programme "Feedback" discussed 5 Live Science in yesterday's show: https://www.bbc.co.uk/sounds/play/m000w5w8. It was their "Out of Your Comfort Zone feature" in which they invite a couple of radio listeners to listen to a show they don't normally hear, and they liked it. Jump to 11:34 for the item which lasts seven minutes.

5

New Theories / How can we measure the expansion of the universe?

« on: 12/02/2021 02:09:02 »

I've been told by someone not to send a paper to a science journal because it's old news, so can someone point me to a published paper (or papers) in a respected peer-reviewed science journal that cover(s) the same ground as this? If so, I want to be able to point to it rather than pointing to my own work and having them dismiss it on the basis that it isn't in a peer reviewed science journal:-

Method to measure absolute velocities through an expanding space fabric, and as a bi-product, to measure the local rate of expansion of space.

David A. Cooper


Abstract

In a universe where galaxies continually move further apart due to the expansion of the space between them, we can show in principle that an experiment can be designed to measure definitive non-zero absolute velocities for objects in space, while it guarantees the avoidance of a null result in any location where there is actual expansion. The local rate of expansion of space can be derived from this measurement with equal precision. Of particular significance, this experiment provides a means to test Lorentz Ether Theory against Einstein's Special Theory of Relativity if carried out in a place where we are certain that expansion is taking place: uniquely in this overlooked situation, the two theories make different predictions about the outcome, so it must be possible to disprove one of them experimentally if expansion of space is real.


Introduction

The expansion of the universe should enable the separation distance between two clocks to increase without changing their velocity through the space fabric, even in a case where they are initially comoving but end up moving relative to each other due to that expansion. In this very special circumstance, the prediction of Lorentz Ether Theory differs from that of STR. LET predicts that the clocks will move apart while continuing to tick in sync with each other and they can thereby reveal their absolute speeds of motion, while STR cannot allow the existence of any such asymmetry. For the purposes of this paper, we assume that the space itself is expanding, thereby carrying galaxies to increasing separation distances. (The alternative explanation of galaxies being sent out into an existing void by the big bang would destroy our current explanation for the cosmic microwave background because that radiation would have been lost outwards into the void long ago instead of continuing to pass us today.) On this basis, we can demonstrate that the existence of absolute speeds of motion cannot be avoided in an expanding universe, and that they can not only be measured in principle, but that measuring them (along with the local rate of expansion) may not be many decades beyond the reach of current technology.

Method

We place two clocks a small number of astronomical units apart in reasonably deep space (outside the solar system), both at rest in reference frame A. We measure their separation distance with respect to frame A, and we synchronise the clocks by that frame once they are in position. To aid this, we place a marker object half way between the two clocks, again at rest in frame A, and frame A will remain tied to this marker throughout. We wait to allow the expansion of space to increase the separation between the three objects by a decent amount, then at a pre-arranged time both clocks send out a signal at the speed of light back to the central marker so that we can measure any difference in their times of arrival there. If the marker is genuinely at rest in space (or if there is no such thing as absolute velocity, or if there is no local expansion) the clocks will still display exactly the same time as each other, as measured in frame A, and the signals will reach the central marker simultaneously. However, if the central marker is actually moving through space in any direction not perpendicular to a straight line connecting the two clocks, one of signals will have to travel a greater distance through space to catch up with the moving central marker than the other, and while at the start of the experiment such signals would still have reached the marker simultaneously due to the skewed synchronisation of the clocks (caused by them being synchronised on the erroneous basis that they were stationary), that will no longer be the case by the end of the experiment due to the extra separation distance introduced by the expansion of space: both signals will have to cross the exact same extra amount of separation distance, but one will necessarily take longer to do so. That timing difference will not be cancelled out in the normal way of relativity.

Clearly there could initially be a null result even if absolute speeds are real (because the system might by chance have an absolute speed of motion through space of zero), but we can repeat the experiment using frame B where this new frame moves relative to frame A in the same direction as the straight line connecting the two clocks in the first running of the experiment. We would now have the marker and clocks begin the second running of the experiment by sitting at rest in frame B. If there was no such thing as absolute velocity, then a null result would be forced for both the first and second runnings of this experiment, and STR predicts this double null result. However, for that to occur, there could be no expansion of the local space in which the experiment is operating.


Discussion

That last claim needs to be expanded upon to demonstrate its validity. If we have a double null result and we also have expansion of the local space in which the experiment is operating, to maintain that null result for both the frame A and B runnings, we would need to have two of the four signals (light pulses or radio waves) travel in the same direction at different speeds, and only a tiny part of that difference can be accounted for by further expansion of the space between them during this short end phase of the experiments. We can arrange for the frame A apparatus (clocks A1, A2 and central marker AM) and frame B apparatus (B1 B2 and BM) to end up in the same vicinity by the end of the first phase of the experiment such that the signals from clocks A1 and B1 can travel together side by side during this second phase of the experiment, so they must match each other for pace precisely. The signals from clocks A2 and B2 could still be a considerable distance apart due to length contraction on the frame B set of objects, but it's easy to see that any difference in their speed caused by the space expanding between them would be dwarfed by the required speed difference to get a double null result. Consider an example where the frame B apparatus is moving at 0.5c relative to the stationary frame A apparatus: there is no possibility of cancelling out the difference caused by the light having to cover the extra distance inserted by the expansion of space (during the first phase) at 0.5c relative to it in one direction and at 1.5c relative to it the opposite way. If we get a double null result, there is categorically no expansion.

Note that due to length contraction, the amount of expansion applying to the frame B apparatus will be reduced relative to the original distance between the clocks over a given length of time, but the duration of that running of the experiment will be increased to match, resulting in the exact same amount of expansion occurring before the signals are sent back to the central marker. This actually provides us with a second measurable asymmetry by causing the signals to arrive back extra late in the frame B case: the added distance caused by expansion of space in the frame B case is not length contracted.

An important question is whether there should actually be any expansion of space locally. If in the worst case scenario the universe expands only at relatively narrow plate boundaries far from galaxies, it could take us millions of years to get our apparatus into position to make any measurements there, but it is likely that the expansion is more evenly spread, and that a reasonable amount is taking place here too, but we now have a way to test that to find out. A double null result would be highly informative because that would rule out local expansion (or show it to be reduced beyond the resolution of the measuring apparatus, so it would be wise to wait until we have built apparatus with one or two orders of magnitude greater precision than we expect to need before we start putting it in rockets). For the rest of this paper though, the reader should simply assume that the experiment is being carried out in a location where there is expansion.

There are a couple of gravitational complications to consider. Even if we carried out the experiment in the middle of the biggest void between galaxies, we would still have distant sources of mass pulling the clocks further apart, so we need to compensate for that effect. An inconvenient way to do this would be to repeat the experiment a long time later when the galaxies are much further apart with their influence diminished, while the increasing rate of expansion of the universe would also lead to increased reliability of the results by amplifying the effect we are trying to measure. After repeating this a few times over the course of millions or billions of years, it would be possible to make a highly accurate adjustment to the results to compensate entirely for the effects of gravitational pull. A similar complication is that in a case where there is more mass attracting the system in one direction than the opposite way, then the central marker could be accelerating in the direction of one of the two clocks, which means it cannot be relied upon to remain at rest in frame A. However, again we could repeat the experiment a long time later when those attractions are both weaker, and then adjustments can be made to cancel out the effect. Such long delays in getting definitive results would be frustrating, but fortunately it would also be possible to calculate the amount of distant mass and its distribution just by looking at it and assessing its extent, then accelerations could be applied to all the clocks and markers to cancel out the accelerations caused by the predicted gravitational attractions. As we improve our measurements and judgements of the amount and distribution of mass in the visible universe, we will be able to carry out this experiment with increasing accuracy over time. Even if this is not done with good information though, we would still get useful measurements of average absolute speeds from accelerating sets of apparatus, just as you can measure that a car accelerating from 40 to 50 mph is moving more slowly than a car accelerating from 45 to 55 mph, so it is not essential to get these judgements completely right.

... (second half follows below)

6

New Theories / Split: Attempts to falsify relativity

« on: 09/02/2021 00:57:34 »

Mod edit: This topic split from "How do we determine the value of time dilation?", https://www.thenakedscientists.com/forum/index.php?topic=81938.0

Picture a situation with clock A at the centre of a circle while clock B travels round it in circles at 0.866c. Clock B ticks at half the rate of clock A on average for lap after lap after lap, and all observers agree that it is doing so. We can now run a bunch of other clocks along tangents to that circle and have them take turns to move alongside clock B for a short time while ticking at the same rate as clock B. These other clocks which never accelerate and just follow straight paths likewise tick at half the rate of clock A on average, though some of them could be ticking faster than clock A. Relativity allows us to take any frame and declare that is is stationary, and then all clocks not stationary in that frame will be measured as ticking slower than a clock that is stationary in that frame, so we cannot pin down which clocks are running fastest or slowest, but the fact that all those clocks on tangents tick half as fast as clock A on average tells us that some clocks do tick more slowly than others, and we know for fact that clock B ticks slow on average without averaging it with any other clock. Clock B must be ticking slower than clock A some of the time, and whenever it is doing so, the clock on a tangent to the circle which accompanies it for a short while must also be ticking at a fundamentally slower rate than clock A. We just can't tell which clocks are ticking slower than clock A at any moment, but some of them certainly are. That is what mathematics actually tells us about this. There's a difference between symmetry of possibility and symmetry of probability. We can point at any of the clocks moving along a straight path and say, "that could be the fastest ticking one," and it's just as possible that it is the fastest ticking one as any other of them that we might point at. However, we can point at any of the clocks on tangents to the circle and say, "that is probably ticking at a lower rate than clock A," and that is correct because the clocks on tangents are ticking at half the rate of clock A on average, as is proved by the fact that clock B is certainly ticking at half the rate of clock A on average. Physicists have simply misapplied mathematics to this and come to an incorrect conclusion.

7

Physics, Astronomy & Cosmology / Is conservation of angular momentum properly understood?

« on: 03/08/2020 00:36:50 »

If an ice skater pulls his/her arms in while rotating, the rotation rate can increase dramatically. Everything I'm finding by searching for information about this describes this case as conservation of momentum with zero external torque. My interest in this came out of a conversation with someone on Quora who claimed to have disproved the conservation of angular momentum, but his attempt to do so was wayward, but I think he has found an genuine error with the idea of conservation of angular momentum and I've identified a mechanism by which external torque appears to be being missed.

Picture a ball on a string flying round in circles. If you shorten the string, the ball is forced to move round a smaller circle, but its speed of movement through space increases. Clearly energy is being added to it by the pull on the string. I've seen a video of a lecture with the lecturer laying down the law about how there cannot be any external torque involved in this because the angle of the pull of the string is at 90° to the direction the ball's moving it, but he's clearly wrong: pulling the string northwards while the ball is moving eastwards will add a northward component of movement to it, and quarter of a lap later, that vector will line up with the changing tangential movement of the ball and add to its tangential speed.

That's the mechanism that I've identified for this, but I can't find any other description of this mechanism from anywhere else, so I'm wondering if it's a new discovery or if it's just old hat. I obviously expect the latter, but my searches aren't finding anything other than people asserting that there cannot be any external torque involved. The person who claimed to have disproved angular momentum is sure that people's measurements are faulty and the increase in rotation speed isn't as big as is predicted by angular momentum, and he's telling me that my mechanism is pseudoscience, so I'd like to find this mechanism spelt out in the existing literature so that I can point him to it, assuming that it isn't a new discovery.

Here's what I think happens when a skater pulls his/her arms in: (s)he can only do this by adding energy released from muscles, and that's the source of the extra energy of the rotation. When the arms are moved back out, energy is lost as heat rather than being maintained in the rotation. In the ball-on-a-string case, you could pull the string in using a motor, and the closer in the ball gets and the faster it moves, the more extreme the pull has to become to be able to move it closer. When letting the string out again, it can do work by generating power with a dynamo, in a lossless system recovering all the energy that was put in when pulling the string.

If you let the string out in one go without holding onto it until the string goes tight at maximum length, the ball will shoot outwards and then apply a huge force to the string as it stops, losing that energy as heat rather than maintaining it in the speed of movement of the ball, so either way that energy is necessarily lost from the tangential movement of the ball. When you let out the string by any method, if we look at the same point in the lap as before, you reduce the northward acceleration at the point of the lap when that acceleration is strongest, so it can't maintain its previous speed and has to lose kinetic energy.

This can't really be a new discovery, so does anyone know where existing documentation of it can be found?

8

COVID-19 / Could a filterless tube to the ground be better than a mask?

« on: 17/04/2020 03:46:13 »

Picture something like a face mask, but it has a simple opening with a valve to let air in (with the option of putting a filter in it for people whose health is fragile), but there would be another tube leading out and down, all the way to near the ground, clipped onto clothing to stop it swinging about. When you breathe out, all the virus (if you're infected) goes down the tube and comes out low down, over one and a half metres downhill from where most people are breathing in.

The down tube could again optionally have a filter in it, and unlike a normal face mask, it wouldn't matter so much if it goes manky as you don't have to breathe in through it as well. Filtering the output may not matter though because the risk is so much lower with it coming out at ground level, added to which, a lot of the droplets will stick to the sides and fall out as liquid drops onto the floor (which can be cleaned regularly if it's in a shop or bus).

If this leads to sufficiently low transmission, people could get back onto well-ventilated public transport and move freely about shops, offices and other work places without pushing the transmission figure back above 1, thereby allowing the virus to die out gradually by not being passed on but without any further need for a severe lockdown. What matters is to keep the transmission low enough to avoid overwhelming the capacity of hospitals to cope, but also to protect the most vulnerable people who would be able to use filters for the air breathed in without having to replace them repeatedly due to them being destroyed by damp. This device would be reusable thousands of times, a simple wash with soapy water making it good as new for the next day.

(One design detail to experiment with is the bottom of the tube - it could bend back up in order not to drip on the floor. Another option would be to have a complete transparent-plastic head-surrounding container to avoid the need to have anything uncomfortable clamped round your breathing holes all day.)

9

COVID-19 / What's the transmission risk at two-metre separation for large grids of people?

« on: 24/03/2020 19:01:04 »

I don't know what the risk of transmission is if two people are two metres apart, but it must increase in proportion to the amount of time that they maintain that proximity. It must also increase depending on how many people are that distance away, and on how many are further away in outer "rings".

If you're 2m away from one person and the risk is n, the risk is going to be 4n if you're 2m away from 4 people. If you're in the middle of a block of nine people, your risk must go up again, but how much? What happens if it's a grid of 10 by 10? How can the risk be calculated?

The air breathed out by someone will presumably spread out in three dimensions, but one of those is blocked by the ground and may also be blocked by a ceiling if you're indoors, and because the air touching objects doesn't move as much as the air further away, you can't assume there will be efficient removal of the virus from the air onto surfaces, but it will certainly get sucked into lungs easily. What prompted this question is the thought that the risk might go up more than people expect as the grid size increases. Clearly there's also another important factor involving the likely number of infected people in the grid, so the risk varies again with that and will grow as we move up the curve.

If we think of the virus radiating out from an infected person and passing through the space that another person is breathing air from, then it the risk should follow the inverse square law with distance for spreading out in three dimensions, but because of the ground and possible ceiling (which I think very little of the virus will contact), it may not thin out so quickly at greater distance from the source and may end up being closer to halving with distance after it's equalised through the vertical space, so that could lead to the risk going up substantially more than expected in a place with many people in it even if they're well spaced out. They're now talking about putting up plastic screens to protect people working at the checkout in supermarkets, but the risk from the immediate proximity of the customers there may not be as high as it is from the general background level of virus in the air.

10

Physiology & Medicine / Why would a young, fit doctor be more at risk from death from a virus?

« on: 02/03/2020 23:01:42 »

I had a great aunt who died at age 12 during the killer flu. It was a big family and she was the last to get ill with it, this after helping look after all the others. I was reminded of this by the death of the Chinese doctor who tried to alert other doctors to coronavirus early on: he was exposed to lots of people who were suffering from it before he contracted it himself and it's been suggested that this resulted in a greater number of units of a virus (is there a word for that?) overwhelming him. Is this an established mechanism or just a guess?

11

Physics, Astronomy & Cosmology / If you throw a mouse or elephant at someone in space, which will move them more?

« on: 03/01/2020 19:04:28 »

The Christmas edition of QI asked a question which they failed to answer. You're in a zero-gravity environment (technically micro-gravity, but we don't need to worry about that too much unless it's a draw), and you have an elephant and a mouse to hand. You have a friend some distance ahead of you and you can either throw the elephant or the mouse at him. Which, if either, would lead to your friend moving more when he catches it.

Let me simplify this a bit though by providing a spring which can be used to do all the initial pushing, so it's now more a case of shooting the mouse or elephant at your friend. The spring will be fully compressed before shooting, and fully extended afterwards. The spring will be considered to have no mass, again to simplify things.

Clearly, the mouse will move faster than the elephant, but also, when the spring pushes between you and the elephant, that will send you moving backwards much more than when you shoot the mouse. Will that make any difference to the speed the friend will end up moving at though?

I should provide weights for the four participants. Let's go for a baby elephant weighing 1000kg. The two humans are both the typical modern amount of 100kg. The mouse is also well fed and weighs 1kg.

(I don't know the answer and I'm unsure as to how to calculate it, so I wouldn't trust any figure that I came up with.)

12

General Science / How could I rescue someone who's being electrocuted in a pool?

« on: 28/12/2019 20:18:14 »

A puzzling tragedy the other day set me wondering about whether it's safe to jump into a pool to try to rescue a struggling swimmer who may be being electrocuted. You wouldn't know where the switch is for anything that might be causing the problem, so is there anything you can do that would make it safe to enter the water? (You also couldn't trust anyone not to turn it back on while you're attempting the rescue.)

There isn't time to dissolve a ton of salt into it and there won't be enough at hand, but maybe there's some kind of liquid that would make the water conductive enough to replicate the properties of sea water through which the current from a lightning strike flows more easily than it does through a person, which is why it's better to stay in the sea than to run up the beach if you're caught in a sudden thunderstorm while swimming. (Fresh water works the other way round: the current flows more easily through you than through the water.)

13

Physics, Astronomy & Cosmology / How does dark matter affect galaxy rotation?

« on: 26/09/2018 01:43:08 »

I've heard various things about dark matter surrounding galaxies and its role in helping the outer material in a galaxy orbit the centre at a higher speed than is predicted for that material from the amount of visible mass in the galaxy alone.

What I don't understand about this is how an outer ring or halo of dark matter further out could speed up the rotation for the material in question rather than slowing it down. If you put more material round the outside (dark matter), that will reduce the inward force felt by the outer visible material, this force acting to try to pull it towards the centre of the galaxy, and this, according to the simulation I'm running in my head, should require it to orbit more slowly in order to maintain its distance from the centre. If you want it to orbit more quickly, I'd have thought you'd need to put the dark matter ring further in than the material that you want to orbit more quickly; not further out.

Where am I getting this wrong?

14

General Science / How might we rescue people from flooded caves?

« on: 07/07/2018 19:07:48 »

Elon Musk has been tweeting suggestions, such as a long inflatable tube which could be put through the narrow tunnel sections to allow the trapped boys to crawl through in air rather than in water. This doesn't sound viable to me though: the current is strong and would likely rip the tube out, but you'd also have no way of getting into it or out at either end.

It seems likely that the place where the boys currently are will flood, so I expect they'll soon have to risk diving them out, and half of them will likely die in the attempt. The best chance for getting some of them out if they do this would be if they're able to use some kind of mask that allows them to talk to a diver ahead of them who would help pull them through on a line to fight the strong current, but communication is vital to avoid being pulled at the wrong times when snagged by rocks. I doubt they have the strength to get through under their own power.

They are now able to pipe air through to them though, and that opens up another possibility, but what I'm about to propose would need to be designed and built in a hurry. Imagine a narrow waterproof tent with no floor which could be pumped full of air from below. It could be anchored to bolts in the rock at the side of a tunnel, leaving plenty of room outside for water to flow past. A series of these could be put in place along the exit route, as well as having a number of them where the boys are currently trapped (which should be put in first). This would take off the time pressure by allowing them to stay for longer in a fully flooded tunnel/cave. It would also allow them to make the journey out in short stages.

I think this approach could save more of them. Is it being considered already? How can this idea get through to the people that can make it happen if it hasn't? I don't have the contacts or the influence needed to get this across - everything I say is simply ignored.

15

Science Experiments / What happens when you put fluorescent ink under Christmas lights?

« on: 30/12/2017 16:58:48 »

I've known for decades that highlighter pens have fluorescent ink that's brighter than the ink in normal pens, but had no way of exploring it properly, until now. I wouldn't have thought of trying it either, but by an accident of luck I had some of my highlighted notes under some Christmas lights when the normal room lights were switched off, and I noticed a greater fluorescence than normal. These particular Christmas lights have four colours of LEDs: red, orange, green and blue. If you point an individual light at the paper with the fluorescent ink on it, for three of the colours of LED it does nothing special, just lighting up the whole page in the colour of that LED. However, one colour of LED does something startling, making all the different colours of the ink light up, even though only one single frequency of light is falling on them. It's nice to see, so give it a go.

16

Just Chat! / Are Sky the experts on all things up there?

« on: 22/08/2017 01:29:39 »

I was watching Sky's coverage of the eclipse and I learned a startling fact. The sun is four hundred million times bigger than the moon, but fortunately it's also four hundred million times further away, which is why they look almost the same size in the sky. I crunched a few numbers after hearing that, and I reckon the moon can only be about a quarter of a mile above us, so the story of Wallace and Grommit visiting the moon may well be true. I'm going to go to the shops tomorrow to buy some materials and tools. Oh, and I mustn't forget to get some crackers.

17

Just Chat! / The new Doctor Who, a woman?

« on: 17/07/2017 18:10:37 »

It's official - the new Doctor Who is a woman. But is this a bluff?

SPOILER ALERT - do not read on if you're a fan of the programme who lives in a country where there is a delay between it being broadcast in Britain and being shown where you are. I should also say at this point that I'm not a big fan of the programme, but have always kept an eye on it because I have always had ideas about writing episodes for it some day, and while I don't like a whole host of things about the way the programme has gone since its revival, I have to say that some of the recent episodes have been the most clever that there have ever been.

So, what's all this nonsense about a female Doctor?

Well, the Master became female a while back, renaming him/herself as Missy. In a recent essipode of the programme she also called herself Doctor Who, which I think is a little clue. He also shot herself (with some kind of weapon) at the end of the last episode, using a high enough power, he claimed, to prevent further regeneration as he was determined to wipe out the good person that he didn't want to become. However, he didn't have time to think that through - Missy would have remembered his act very well from when she was him, so she would have shielded herself against that terminal blast. She will most certainly survive and regenerate. She will also complete her transition to being good, effectively becoming a second Doctor Who. That means the universe now has two Doctor Whos, both good and doing the same job - one of them male and the other female, and both may well use the same name. I may be wrong, of course, but I hope that's what they're going to do with the programme.

18

General Science / How can the inhalation of air pollution in towns be minimised?

« on: 12/06/2017 17:41:42 »

I've been catching up with a batch of recent broadcasts of the Naked Science radio programmes on iPlayer before they vanish, and one of them had a bit about exposure to air pollution which gave some tips for minimising the amount of particulates and noxious gases that you might inhale. A team from Cambridge carried out experiments in London with portable measuring apparatus which they could walk about with. The found the highest readings inside a taxi, and lower levels when walking by the river, but the most interesting thing was that they found a significant difference between the kerb side of pavements and keeping close to the buildings (the latter being better). They also said that wearing a surgical mask doesn't help as most of the air goes in and out round the sides unless you use something more substantial like a gas mask.

This leads me wonder though - given that there's a significant difference between the kerb side of a pavement and the wall side, how much difference would a bit of extra altitude make? Might it be worth wearing a long snorkel, and how tall would it be sensible to make it? Of course, another way of improving air quality would be for everyone to carry a tree about with them, but that's maybe a bit less practical.

19

New Theories / LET: gravity and magnetism explained

« on: 13/05/2017 19:36:11 »

I was thinking about gravity last night and it occurred to me that some of the things about it that seem magical needn't be so magical after all. The biggest problem is where the "potential energy" is stored when you lift an object. The answer's simple though - it's stored in the fabric of space.

For an object to exist in deep space, there is energy making up the material of that object, and there's also kinetic energy if the object's moving through space, but there's also some extra energy, and quite a lot of it too, which is stressing or distorting the fabric of space at that location. When two objects move closer to each other, the amount of energy stored in this way in the space fabric reduces, and it now appears as an increase in kinetic energy as the objects accelerate towards each other. That is what powers the acceleration. If they collide and stay together, the kinetic energy remains, but as movement of atoms, and we then call that movement heat. That energy can then be radiated off as infra-red light, and this energy that moves away from our objects is energy which was previously held as stress in the fabric of space.

When you lift an object, you are causing the fabric of space to accommodate it differently, and that involves putting energy into that fabric. This is like with bubbles in washing-up water which can accelerate towards each other as the surface tension rearranges the shape of the surface in order to minimise the amount of energy stored in it - that stored energy is turned into kinetic energy in the same way, and then it becomes heat. Once we understand where the potential energy is stored, it's all becomes obvious - all we have is a stressed fabric trying to get to a lower energy state.

We see the same thing in chemical bonds where high energy bonds are less stable than low energy ones - again it is the fabric of space in which that extra energy is held, and it's held as stress or distortion. Many fools laugh at the people who came up with the idea of phlogeston, and yet the idea wasn't far wrong at all - it was simply potential energy held in the fabric of space.

The same applies to magnets. A north or south pole stresses the space fabric, meaning that wherever there's a magnet there is extra energy accompanying it which is held in the space fabric. If you move a north pole close to a north pole (or a south pole close to a south pole), that adds to the stress and requires you to put more energy in. If you move a north pole next to a south pole, that reduces the stress on the space fabric and allows stored energy there to be released. With the magnets stuck together, they are in a lower energy state and you need to put more energy in to move them apart because moving them apart needs to distort/stress the space fabric more.

What seemed to me like magic yesterday no longer seems very magical at all because I can now see where the energy goes to and where it comes from - it doesn't just appear out of nothing. This also means that gravity and magnetism works without depending on force carriers moving backwards and forwards between different pieces of matter (although there may still be an equivalent to force carriers of some kind operating in the fabric to shift the pattern of stress/deformation as matter moves along through it). We have a rational mechanism for all forces, and it depends on a space fabric with properties able to accommodate them with different forces stressing it in different ways.

20

Physiology & Medicine / Does saliva have any role in digestion?

« on: 16/04/2017 19:45:51 »

I've often heard that you should chew food thoroughly in order to let saliva start the digestion process, but I don't see how it can have any significant impact in comparison to the battery acid in the stomach which goes to work on the food moments later. Is its real purpose just to dissolve soluble molecules in the food so make it possible to taste them in order to judge the quality and to determine things like how much sugar might be in them?

Also, how long does it take before any sugar in the food can actually be used by the body? Does it get through the wall of the mouth, throat or stomach to any significant degree (in the way cyanide clearly can) or does it have to wait until it's gone beyond the stomach?