Do rockets punch holes in the ozone layer?

Do rockets punch holes in the ozone layer?

we know that the major culprit for making holes in the ozone layer are chemicals called CFCs — chloro-fluoro carbons. These are things that were used in aerosols, even in aspirin inhalers, but also in fridges as refrigerants, and they were used in huge amounts until the Montreal Treaty came in, in the late 80s to try and ban them. What provoked that was that a group of scientists including Brian Gardner (who appeared here on The Naked Scientists a few years back) had actually noticed this massive hole opening up over Antarctica in the mid-to-late 80s and this hole actually grew to be the size of Australia at its peak. It stopped growing; it’s actually beginning to shrink a little bit now and that’s because we have stopped using these chemicals. The reason that they concentrate down in the Antarctic is because the Antarctic is an isolated continent. It’s completely surrounded by ocean and this creates something called a circumpolar current, and this has a sort of whirlpool-like effect in terms of air; and it draws in and concentrates these molecules over the Antarctic over winter when it’s very dark. They then accumulate in high clouds over the Antarctic and when the sun comes out the following spring the sun breaks down the CFCs and they get turned into reactive chemicals that would then react with the ozone and deplete it. They are, by far, in a way the worst culprit. We don’t send enough rockets and spaceships up into space to make a huge difference, I wouldn’t have thought, in grand scheme of things. So I think although we have to be environmentally conscious, I think the benefit of sending rockets into space in terms of what they can do for satellites and furthering research is far greater than the small bit of damage they might make to the ozone layer. So I think on the whole, probably not, it’s probably more a manmade, anthropogenic problem. But great question, thank you for that.

Can Plants get Cancer?

Can Plants get Cancer?

Cancer in the context of a human has got a specialist disorder. What we mean by cancer, our cells that have lost the ability to obey the normal signals that control and dictate how things grow and move and obey signals that tell them not to go to other places in the body and not to grow through boundaries of tissues and not to disobey ‘kill yourself’ signals. Because every cell in the body is programmed to die unless it’s told otherwise.

Cancer cells ignore that signal and so, they are immortal as Richard Van Noorden was saying, and they also disobey all those normal regulatory signals that can spread to other bits of the body and cause secondary tumours. And it’s usually those secondary tumours that cause problems. Now, plants don’t have a disease like that. They don’t get secondary spread through their system of disease which starts in one part of the plant and goes elsewhere, at least in the form of the cells from the plant itself. But they can get localized growths, a cancer-like phenomenon and just like some human cancers which can be triggered by microorganisms, cervical cancer for example is caused by infection with a virus, human papilloma virus. Also, gastric cancer in the stomach is caused by bacterial infection, Helicobacter pylori, is strongly associated with gastric cancers.

In plants, there is an environmental organism, it’s called Agrobacterium tumefaciens, this is a soil dwelling bacterium and it has something called a transposon. This is a piece of genetic material which the bacterium injects into the plant’s own genetic material and that transposon carries genes which code for growth factors. And it causes the plant cells to begin to grow out of control. And the idea is to produce a big growth locally on the plant that then gives a home and provides protection to bacteria and that’s a Gall. And it’s very, very common, it’s called Crown Gall disease when the plants actually have it, but it doesn’t spread predictly to other bits of the plant. So there are some similarities between human cancers and animal cancers and plant tumours like Crown Gall disease, but it’s not the same disease. There’s nothing systemic as far as I know that does the same thing but it’s a very good question.

How far would electricity carry in the sea?

How far would electricity carry in the sea? If a toaster, connected to the mains at 240 volts was accidentally dropped into the ocean, let’s say the North Atlantic, would the sea life be electrocuted? And if so, how far and how deep from the toaster would these electrical shockwaves travel?

Seawater conducts electricity reasonably well, but not very well. It’s about a 10 millionth as good as copper. So, you will get electricity flowing through it, but it will also depend on where the other cable is because electricity always moves from one place to another place. And if the other connection to the circuit is an awful long way away, then you get very, very small currents and it’s not going to do a lot of damage. If you’ve got two contacts a foot apart and a fish swims between them then it’s almost certainly going to get electrocuted. So, I think it depends an awful lot about how you set up this test.

Do animals speak regional languages?

Do animals speak regional languages? If I emigrated from South Africa to South America and I took my family dog with me, would his bark be understood by South American dogs?

Animals do indeed. Some of them do have regional accents, if you like, or dialects. And whether or not your dog would understand another dog might come down to breeds, rather than necessarily where it’s living in the world. But yes, animals do. We know that some birds have regional accents, some amphibians do, and if you jump into the oceans, there are creatures there that definitely have different languages and accents of their own. And that is the whales and dolphins, the cetaceans. And various studies have shown that if you listen to the sounds that some of these great whales are making, you can actually work out pretty well where it came from. Blue whales are one example and scientists have worked out that there are about nine regional populations of blue whales that seem to have their own distinct languages. And so, that might be something that has implications for things like conservation. Maybe we have to think about those nine populations as being slightly separate and different.
Is that because the baby whales learn to speak by imitation from parents and that’s how this regionality arises?

Probably, we know so little really about these amazing creatures, given the huge area of ocean that they live in, things like that. So these sorts of questions, we don’t yet know. For example, we also don’t know if they could understand each other between these regions. We don’t know that yet. Killer whales are another example of fantastic regional dialects. Along the eastern pacific coast of North America, there’s been a lot of study of killer whales living around Vancouver and Alaska. And these guys also have regional dialects. In fact, you can tell whether or not the individual killer whale belongs to a residential population, whether it’s a transient individual that’s coming through or whether it’s one from offshore because all these different killer whales basically speak with different accents, a little bit like different accents throughout the UK. We could tell where someone comes from, from the way they sound. I think this is fantastic.

They've also shown that there's a genetic link which is fantastic which shows that there seems to be some way that killer whales can tell how related they are to each other. And therefore, try and avoid problem with things like inbreeding, just by the way that they're talking to each other. So I think that’s just really fantastic

Is it true that vitamin C helps to cure cancer or perhaps even prevent it? And if so, how’s that possible?

Is it true that vitamin C helps to cure cancer or perhaps even prevent it? And if so, how’s that possible?

No, it isn’t. This is something that Linus Pauling put around - the idea that you take massive doses of vitamin C and it can stop you getting cancer or treat cancer. And basically, there’s no scientific evidence that this works. However, about a year or so ago, there was a paper that showed that injections of vitamin C may help some treatment. I can’t remember all the details, but we certainly blogged about it on the Cancer Research UK Science blog. But it’s important to stress that obviously, vitamin Cs are anti-oxidants and taking high doses of anti-oxidants may well interfere with some kinds of cancer treatment in ways that we don’t really know and again, it’s something that we have blogged about and it’s an area that’s really quite interesting because people do love to take vitamin pills. Indeed. There was also a Meta analysis by Goran Bjelakovic who’s at the University of Copenhagen in Denmark. I remember this coming out last year and they looked at many, many thousands of people who’d all been in little trials on giving anti-oxidant vitamins like vitamin A, vitamin D, vitamin E, vitamin K, selenium, and that kind of thing, vitamin C, and compared that with people’s outcomes if they didn’t take vitamins. And in fact, in many cases, they found that some chronic vitamin treatments actually resulted in people having a higher mortality rate and morbidity rate than people who didn’t take any of these supplements. A modest increase in risk, but at the same time, vitamin A and vitamin E did increase the risks. So, the chances are, yes, it’s based on sound physiological principles, trying to take anti-oxidant but the outcomes don’t necessarily fit the facts at the moment. So, needs more work I guess is the bottom line.

Can stem cells treat brain diseases?

Can stem cells treat brain diseases?

There’s a lot of promise in stem cells, but we’re probably several years away from being able to see the benefits of the research that’s going on. You mentioned at the beginning of the program that brain cells, once they're dead, they're gone and they can't be replaced from within the brain because brain cells don't divide. And the hope of stem cell research in neurodegenerative diseases is that you can take these stem cells which are capable still of dividing and becoming any kind of cell they like, put them into the brain and they’ll then re-grow, and replace the cells that have died. But as you also mentioned earlier on, the brain is a phenomenally complex thing and performing its functions normally, depends not just on the cells being there but on the connections, the billions and billions of connections that there are between the brain cells. And even if you could get the brain cells, the stem cells to differentiate into neurons that behave completely normally, you’d probably never be able to get them to make all the right connections. So there’s certainly be a lot of work, training the stem cells to make the right connections and behave the same way as the cells around them.

What are the floaters we see in the eyeball?

What are the floaters we see in the eyeball? And would it be possible to have a coil of thin wire in ones spectacle frames which would attract floaters to the extremities of the eye so that they would not float across the eye and be a distraction?

Well, floaters are actually very common. It is an age related phenomenon for the most part especially as we get in to the 40s and older. And what it is, is a clear gel in the back of the eye starts to condense and coil less and cloud over. Hence, that what the person sees will be spots and threads and shadowy clouds or cobweb type shadows which move around in the vision. Most of these floaters are considered benign, but it is worth getting a good eye examination to make sure that it’s not part of something more serious such as a retinal tear or a retinal detachment. The common advice that most people are given is to just learn to live with it and hope that it will go away. Now, the traditional treatment as I said is just to learn to live with it. There is actually a surgical intervention, a surgical procedure called the vitrectomy and it involves putting small instruments inside the eye to essentially suck out the gel in its entirety and replace it with salt water. As you can imagine, it’s invasive, it has complications, commonly cataract and sometimes even retinal detachment. And as far as your reader’s question about putting a coil of wire, it reminds me of a Steve Martin movie called The Jerk where he did put a little handle, a little wire on some glasses and in the movie, everybody got cross-eyed. Well, that wouldn’t happen, but there’s nothing you can really do to distract yourself from those floaters because they are inside the eye and they're constantly there. I have an unusual situation where I have a practice entirely devoted to treating floaters and I use a laser. So I use a highly focused laser on the floater material itself and vaporize it, convert it to a gas, the gas goes away and the floaters are gone.

How many LCROSS NASA missions would it take to change the orbit of the moon by 1%?

How many LCROSS NASA missions would it take to change the orbit of the moon by 1%?

What they were doing was firing the top stage of a centaur rocket and crashing it into the moon. They’ve been trying to watch the plume of stuff that comes up from that to see if there is water in that plume.

Now the centaur rocket weights about 2.3 tons and it’s going at about 10,000 kilometres per hour, that’s 2,800 metres per second, which means it’s got 6.4 million (6.4 x 106) kilogram metres per second of momentum. That’s an awful lot of momentum. For anything on Earth, that’s a scary amount of momentum. However, the moon has got awful lot more momentum than that. It’s moving at a kilometre per second and it weighs 7.3 x1022 kilograms.

That means the moon has got 7.3 x 1025 kilogram metres per second of momentum.

So, how many LCROSS’s crashing into it would change it’s momentum by 1%?

7.3x1025 minus 6.4x106 is roughly 1x1019

So about 1019 collisions. So that’s 1 with 19 zeros after it (10,000,000,000,000,000,000!).

And actually, an LCROSS’s momentum compared to the moon is about the same as 1 millilitre of water compared to all the water in all the earth’s oceans.

Why are background radiation levels so much higher in Germany than the UK?

Why are background radiation levels so much higher in Germany than the UK?

We spent some time looking at geological maps of Germany in the UK and our conclusion is that a lot of Germany is made of granite and granite releases a radioactive gas called radon. But the UK isn’t completely bereft of radioactive rocks. A lot of Cornwall, a lot of Wales, quite a lot of the Pennines and some of the Peak district and of course, Edinburgh is made of granite and does release radon. And there was some research I think a couple of years ago that showed that people Cornwall are actually getting quite a significant dose of radioactivity that does increase the risk of lung cancer in these areas. And in fact, if you smoke and live in places like Cornwall that are very granity, that’s actually a much more significant impact on your cancer risk than if you just live there and didn’t smoke. So, if you live in Cornwall or anywhere that looks a bit granity, then don’t smoke. But as to whether the background radiation is higher in Germany versus the UK, it really depends where you live. If you live in a very granity bit of Germany, yes it will be higher, but if you live in a very granity bit of the UK compared to a non-granity bit of Germany then obviously, it will be higher in the UK.

Is the blood-brain barrier real?

Is the blood-brain barrier real?

Absolutely. People talk about this blood-brain barrier. This notional structure which in some way keeps the brain isolated, cocooned inside you biochemically and physically-away from what's happenign in you blood stream and it;s absolutely true. The history of the blood brain barrier goes back a hundred and something years to a guy called Paul Ehrlich, who was a German scientist, he was interested in dyes initially. He used to inject dyes inot animals and then see which bits of the body got stained. andhe was intrigued to see that when he put dyes into the blood stream, much of the time the dye did not get into the brain. And so he realised there must be some kind of barrier separating what goes round in the blood stream from the delicate issue inside the brain. We not understand more about what this blood-brain barrier is. It's a bit contrived, what what's going on is that you basically have special junctions between ceels that line the surfaces of the brain, that separate the brain tissue from blood vessels and these cells make very tight junctions, that's what they're called, and this effecttively means that there's a barrier which is the membranes of those cells separating what's in the blood stream from what's in the blood tissue.

And what this means is that certain substances can move very easily into the brain, especially if they're substances that can dissolve well in fat, because of course the membranes of cells are made of fat. So lipid-solube drugs like heroin, cigarettes-nictone, cocaine, they're very oily molecules. they go into the brain beautifully and that's why they tend to be addictive. Because they move preferentially into fatty tissue like the brain. Other substances which don't dissolve in fat very well, don't get into the brain very well. But there are some exceptions. Those exceptions are things that the brain needs. So sometimes if it needs a certain chemical that wouldn't be able to diffuse in very easily, it has special transporters which can scrutinise what is going past in the blood, grab goodies that it wants and move those into the brain. This is what people found when they were giving the drug L-Dopa for Parkinson's Disease. -Dop is an amino acid, dissolves in water, doesn't dissolve in brain tissue very well but it gets into the brain much betetr than it should do and the reaon is theer are these special transporters that get hold of it and shove it into the brain.