1

Physiology & Medicine / What isotope to commit murder undetectably?

« on: 12/06/2024 07:26:00 »

This is not a post evidencing an intention to commit a crime!

A friend has approached me regarding a novel he is writing. One of his plot lines involves a manner of a person dying (possibly killing themself, I'm not sure) through ingestion of a radioactive source that will be delivered to their home, do the deed and cast the die, setting in train a death spiral, but then decay to an undetectable state so no one would know.

We were discussing what isoptopes, if any, would fulfil these criteria?

I guess we're looking for something that is an alpha source (strongly ionising, but poorly penetrating so the postman wouldn't get harmed and it would be easier to conceal), soluble, and with a short half life.

Thoughts...

2

Physics, Astronomy & Cosmology / Will water at low pressure still freeze at zero degrees?

« on: 31/01/2023 11:58:52 »

Water under a lower pressure boils at a lower temperature because the lower pressure makes it easier for molecules to gain sufficient energy from the liquid to sever the intermolecular forces within the fluid and escape as a vapour. But what happens to the freezing point?

3

Geek Speak / Should you secure erase an SSD before giving it away, like you should an HDD?

« on: 31/01/2023 09:59:50 »

I was contemplating giving one of my children my old laptop because hers is falling apart.

My one uses SSD storage. But because I've used it at the hospital and for clinical work, while there should be no personal data there, I wanted to erase it with a data over-write to be absolutely certain.

But then I was warned that this can damage an SSD storage device.

My questions are:

1) Is data over-writing necessary for an SSD storage system
2) How can a single over-write possibly damage / prematurely age the device more than routine use does anyway?
3) Is a multiple pass overwrite unnecessary on an SSD.
4) If I cannot over-write it, how should I make the device "data safe" before passing it to a third party?

4

Geology, Palaeontology & Archaeology / Is this a fossil worm?

« on: 02/10/2022 20:49:31 »

I found this piece of chert in East Anglia. It has a surface impression running right around the stone of something resembling a worm. Can you suggest what it might be?

IMG_20221002_204236.jpg (2333.7 kB . 3120x4160 - viewed 2766 times)

5

Geology, Palaeontology & Archaeology / What is this lumpy rock found at Lyme Regis?

« on: 12/08/2021 00:11:37 »

Can anyone offer me a diagnosis on this specimen I picked up yesterday on the beach at Lyme Regis.


ROCK.jpg (1257.23 kB . 2851x3001 - viewed 10294 times)

It's heavy; the lumpy bits are smooth ovoid balls about 10mm across and the material surrounding them looks "spongy". In some places there are cup-shaped recesses left where the balls appear to have dropped out.

To my untrained eye, it looks like a fossilised fish egg case.

Can anyone help?

6

General Science / MOVED: Science Jokes!

« on: 16/12/2020 16:36:20 »

This topic is not a science discussion, so it has been moved to Just Chat!.

https://www.thenakedscientists.com/forum/index.php?topic=81184.0

7

Geology, Palaeontology & Archaeology / What is this stone that looks like it's been attacked by woodworm?

« on: 12/11/2020 17:41:06 »

This was found in south Cambridgeshire, UK. It looks like a stone that's been attacked by the flint equivalent of woodworm! There are signs of these pits running right through the specimen. The images below are the "top" and "bottom" surfaces of the piece.

Can anyone offer a diagnosis for me?

FOSSIL-1.jpg (803.46 kB . 2476x2724 - viewed 5972 times)
FOSSIL-2.jpg (847.95 kB . 2458x2698 - viewed 6082 times)

8

General Science / MOVED: lots of good topics on here

« on: 12/11/2020 13:21:57 »

This topic has been moved to Just Chat!.

https://www.thenakedscientists.com/forum/index.php?topic=80891.0

9

Geology, Palaeontology & Archaeology / What is this round-shaped pebble with a conical end?

« on: 07/11/2020 09:31:44 »

I picked this up in my garden in Cambridgeshire. It's a modest-sized spherical "pebble", although one aspect is conical; the surface over the spherical component has a pitted pattern. The conical part is smooth. I suspect it's some sort of fossilised marine entity, but I would appreciate knowing exactly what it is, if anyone can point me in the right direction please?

CS-stone1.jpg (372.09 kB . 1500x1500 - viewed 6234 times)

CS-stone-2.jpg (441.39 kB . 1500x1717 - viewed 6165 times)

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Geology, Palaeontology & Archaeology / What produces this strange chipped pattern on the surface of this stone?

« on: 12/10/2020 10:00:31 »

I was walking in the fields here in Cambridgeshire the other day and picked up this interesting piece. I'm wondering if anyone can explain to me how this pattern forms?

CHRIS-STONE.jpg (801.88 kB . 2431x2524 - viewed 8277 times)

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Plant Sciences, Zoology & Evolution / MOVED: the root of our universe - Existence of cause and effect?

« on: 29/09/2020 12:15:13 »

This topic has been moved to Physics, Astronomy & Cosmology.

https://www.thenakedscientists.com/forum/index.php?topic=80655.0

12

Physics, Astronomy & Cosmology / What power was needed to transmit images of the Moon landings home?

« on: 29/09/2020 00:32:40 »

This question dropped into our Naked Scientists inbox, and I thought it would be perfect fodder for us to dissect and discuss here:

Can you help me explain this to my friend? here's what he said:

I do believe we had the technology to get to the moon but I do not believe we had the technology to transmit an analog TV signal from the moon to the earth. I looked it up myself with no moon context. I looked up how much power is needed to transmit an analog TV signal. Turns out about 50,000 watts per 25-50 miles for VHF. Analog VHF TV signals dissipate quickly, they spread out, they don't travel like a beam. Even with 50,000 watts and a very tall aentena matched to the power (about 100 feet) the signal would be too weak to lock onto after 50 miles. I'm supposed to believe that six foot TV antenna on top of The Eagle could transmit at a high enough power for the signal to reach earth capable of being locked onto? The entire lander was operating on a 12 volt car battery!

What does everyone think?

13

Physics, Astronomy & Cosmology / Why does angle of reflection equal angle of incidence?

« on: 14/09/2020 07:46:44 »

I am anticipating this question surfacing, based on what my children are learning at school at the moment, so I want to have a Boris Johnson "oven ready", Naked-Scientists-forum-approved, answer to this!

When considering a mirror surface, a light / electromagnetic ray reaches the mirror surface. It interacts with the cloud of electrons around the atoms on that surface and makes them vibrate. Those displacements of a charged particle - the electron - constitute a moving (accelerating and decelerating) charge, so electromagnetic waves are produced. This is the "reflected" ray. Am I right so far?

So what property of the atom / electrons means that the light ray that issues from the surface in this way have the same angle as the incoming ray?

14

Just Chat! / Wow - very impressive

« on: 11/09/2020 17:51:12 »

Stumbled on this on YouTube after watching Geddy Lee play for Yes at their induction into the Rock and Roll Hall of Fame. I was very impressed!

15

Just Chat! / Image copyright infringement claim SCAMS

« on: 07/09/2020 16:42:00 »

Dear all

We've noticed in recent months that we're starting to receive a lot of fake image copyright infringement notices.

Basically, identifying copyright image infringement is making people more money than actually taking photos these days, so a whole industry has sprung up providing services (computer programmes) that prowl the internet looking for potentially unlicensed uses of images and then report back to the owner. While this is the electric image equivalent of ambulance chasing, it is nevertheless a legitimate industry, despite the heavy-handed tactics and exorbitant sums charged by these services for what can sometimes be a genuine error committed in good faith.

However, alongside the legitimate operators, there has emerged the usual pond-scum line up of rogues and deceitful operators. Some of them steal public domain images, post them to a fake flickr account, claim ownership, and then approach people who have used them quite appropriately and demand a settlement. Enough people fall for this to make it worth their while.

The other tactic we've noticed is to use this for SEO (search engine optimisation). Basically they find an image relevant to a particular industry / topic, contact sites that have used it, claim to be representing a client who owns it, and then require that it needs to be appropriately "credited".

Apparently, what that client wants is a link to their website in return for your usage.

What's a bit surprising, however, is that the "clients" seem to have all manner of strange websites like "ridyourgardenofweeds.com" and "Iwanttorentavanforday.com" [these are contrived names I made up as examples and which are not active urls, so apologies to anyone who really owns them, if they subsequently are registered]

What's actually going on is that the scammers are trying to build a link network to a site that their either own themselves, or someone is paying them to promote, to raise its search rankings. The more incoming links from external sites with content relevant to the site you're trying to promote, the more highly Google regards the site and the higher it ranks. This can be good for online revenues, or to sell the site as a going concern (also big business these days). Naturally, people will have put relevant pictures alongside relevant content, so if you get a link from that page, it's gold dust. In some cases, the owners of the promoted site may be completely unaware that this is going on and are paying for what they think is a legitimate SEO operation.

The latest scoundrel trying to rip everyone off is "Jason Perales" of "legal media check". Here's his missive:

"On Thursday, August 27, 2020 at 4:34 AM, Jason Perales <jason@legalmediacheck.com> wrote:

Hi Chris,

You are using my client's image in an article on https://www.thenakedscientists.com/articles/science-features/science-sunday-lunch-question-taste. We're glad that it's of use to you

You can find the image at https://commons.wikimedia.org/wiki/File:Sunday_roast_-_roast_beef_1.jpg

It’s not an issue at all but we would greatly appreciate it if you can give credit to our client as they have produced this image that you are using. 

You can simply add an image credit (by adding a clickable link) on your article to our client’s website. Since you have been using this image for quite some time now as per the date of your article’s publication, we feel that it’s the right thing to do.

Feel free to ask any questions that you may have.

Jason Perales
Content Head
Legal Media Check

Silly boy. If it's "not an issue at all", then I don't need to do anything about it, do I? (They just put this so that, legally, they are limiting what they are actually alleging, and can then claim they made a mistake, if challenged, later).

Anyway, what Jason's bot also hasn't picked up is that our usage of the image is already appropriately credited to the creator, who made his image publicly available in 2005 on flickr: https://www.flickr.com/photos/adactio/10098413/

Meanwhile, a quick look at Jason's website (legalmediacheck.com) also reveals a shabby rush job containing hastily filled templates and bits of irrelevant content intended to look sharp and hide the reality. Don't be fooled: this is a sheep in wolf's clothing.

Consequently, I ignored "Jason's" communication, but he's a persistent fellow and had the cheek to spam me again today:

On Sunday, 30 August 2020, 10:43:27 BST, Jason Perales <jason@legalmediacheck.com> wrote:

Can you please connect me to the right person if this isn't part of your department?

So I replied to Jason because you'll see that, craftily, in his initial salvo he's not revealed who the original owner of the image is. This way, the people who reply are probably more gullible and have already fallen for the ruse, so are less likely to waste Jason's precious time when he could be off spamming and defrauding other people of links.

This is what Jason told me today:

Thank you for replying, Chris.

Can you please give image credit to Carnivore Style?

Link: https:https://carnivorestyle.com/
Credit Name: Carnivore Style

It can be anywhere in the article. Just make sure that it's a clickable link.

You'll see the key is there in that last line - got to make sure it's a clickable link so we can drive as much juicy traffic to the site he's trying to promote as possible.

Now isn't it interesting that the owner of the image we've used (on a page authored in 2005) is according to Jason a new venture that seems to have sprung to life only in 2019; it's called "carnivore lifestyle". What a coincidence that a picture used on our site - within a high-ranking article about cooking and food - has got Jason's attention...

Jason's clearly a bit of a slapdash jerk though, because he's messed up the URL there (duplicated "https://") so I can now have a bit of fun now; silly me has not realised how the web works, so of course that link won't work on my site, and I don't really understand what I'm supposed to link to, so I've had to write to the owner of the website, listed on the site as "Timothy Woods" to ask for his advice on how to place the link and to where...

Mr Woods (assuming he actually exists, but I have my doubts) and the website itself might be totally innocent in all this, but the content is pretty thin on the ground, and they don't have a huge amount of content yet despite having a significant team going by the mugshots on the "About us" section of the site; the business is apparently based in Florida. They do have a phone number though, so I thought I'd ring them up.

What I got was someone's voicemail: "Cecil Lee", by the sound of it. No mention of Carnivore Style, or the team of content creators or the editor himself. Very ominous. I declined to leave a message. We'll see what Mr Woods has got to say in the meantime.

Update a day later...

How odd, no reply from Mr Woods at Carnivore Style, but, hang on, what's this in my inbox.

Well if it isn't Jason back, and he's getting a bit impatient by the look of it:

Jason Perales <jason@legalmediacheck.com>
To: Chris Smith
Wed 2 Sep at 12:36

Hey, feel free to let me know if you have any concerns regarding my previous email.

What do you think will work best for you?

Now isn't that wording a bit strange? Why's he asking me what would work for me? Or could it be that when I wrote to "Mr Woods" and asked him what I should be doing with regard to linking to his site, it actually went to Jason and now forgetful Jason's slipped up and answered on behalf of "Mr Woods".

Anyway, I've written back asking "Jason" for his client's proof of ownership of the image in question. My guess is we won't be hearing back from him again because he'll know the game's up.

UPDATE - 4 days later...

Well, the weekend has come and gone, and Jason has gone with it. Despite a couple of email prods from me "reaching out" to him and asking him for the confirmation that his website - sorry - the website he's "representing" own the rights to the image so we can put in place this link for him - sorry, old habits die hard - his "clients", I've not heard a thing. I wonder why...

Meanwhile, should I also be referring to Jason as "Alice Felix", who's also a "Content Head" at legalmediacheck? (Gosh, they must be a busy company to have so many content heads.)

The reason I ask this is because it looks like others have heard from legalmediacheck too, specifically "Alice" that time:

https://www.phoenixfm.com/2020/07/07/legal-media-check-scam/

We blog a lot here on phoenixfm.com but there’s always a worry that we accidentally use an image we’re not allowed to use. You can’t just lift something off Google image search – that person may have paid for the privilege, and we’re an impoverished community radio station with a zero budget for virtually everything. So we need to be careful.

If I need various stock images, I go to one of the free stock image websites. It can be hard finding them, because the ones that Google tell you are free aren’t necessarily free. You have to read a lot of small print.

This morning at 11am I had an email from Alice Felix, Content Head at Legal Media Check. She said:

Hi Paul,

You are using my client’s image (attached below) in one of your articles (URL given). We’re glad that it’s of use to you 🙂

There’s no issue if you’ve bought this from our market partners such as Shutterstock, iStock, Getty Image, Pexels, Adobe, Pixabay, Unsplash etc.,

However, if you don’t have the proper license for the image then we request you to provide image credits (clickable link) on your article. Or else this will be against the copyright policy.

Unfortunately, removing the image isn’t the solution since you have been using our image on your website for a while now.

Feel free to ask any questions that you may have.

Alice Felix
Content Head
Legal Media Check

This just seemed a bit weird. I Googled Alice, and it appeared that she lives in Texas, so why is she sending out messages at 5am? Also, some of the English on it just didn’t seem quite right either (“Or else this will be against the copyright policy”, etc). Also, for a legal letter it wasn’t very aggressive, which I was grateful for, but it set a few alarm bells ringing. Also, this part at the end of her email really surprised me:

Unsubscribe (link) if you don’t want me to followup with you.

So I’m being asked not to violate your client’s legal rights but I can unsubscribe? I went back to her and said:

I have spoken to the author who tells me the image was found from a free website. However I am happy to give you a credit, can you please give me the information required?

She replied very quickly (so she’s probably not in Texas unless she’s a really early starter).

Hi Paul,

Thanks for getting back to me.

Can you please give image credit to (Van Hire Company)?

Link: Van Hire Company’s link
Credit Name: Van Hire Company

It can be anywhere in the article. Just make sure that it’s a clickable link 🙂

Thank you.

Beginning to think that with all the smiley faces, this is not a proper legal firm.

I clicked on the link. It’s a van hire company. Not a photographer trying to make a living.

Obviously I’m not mentioning the name of the company, because that’s what they want. We get a lot of people asking us to link to them, because our website has a good standing with Google. Sometimes they offer to pay, which is great as the money goes in the pot to help run the station. (If you’re interested, the going rate is about £50). Sometimes they try to get it for free. But I’ve never had an SEO company pretend to be a legal firm and threaten me (very politely) with action just so they can get a free link for one of their clients.

The Van Hire Company stinks too. The website gives an address of London N7 and a phone number starting with 020, but it’s written in broken English and the prices are all in Euros.

I decided to email her back.

Can you please send me proof that Van Hire Company is the photographer who holds the copyright?

They seem to be the magic words, as the correspondence ended very abruptly.

So if you’re reading this, host your own website and you get any emails from Alice Felix, Content Head at Legal Media Check, save yourself some time and put them straight in the bin …

Meanwhile, browsing the web a bit, turns out that "Audrey Griffin" and "Nancy Diaz" are also in the frame as "Content Heads" at legalmediacheck.

So, my conclusion is that Alice and Jason clearly don't exist, at least as real people; but hat's off to the scammer who is obviously an equal opportunities impersonator.

And if anyone else has run-ins with this or a similar bunch of crooks, please document your experience here so that others may discover these notes and be spared the same deceit. Naturally, if any of the above-named scammers would like the right to reply, this is the perfect venue.

"Jason", the floor's yours...

16

COVID-19 / Do HEPA filters on aeroplanes remove coronaviruses?

« on: 06/09/2020 11:56:29 »

I received this email from listener John, who had heard a piece on this week's edition of 5live science and The Naked Scientists concerning the safety of flying and the transmission of respiratory infections aboard aircraft.

We discussed this issue in the light of the recent coronavirus outbreak on the flight from Zante.

John has raised some good points and provoked a thorough answer from me, which I feel may help other readers. Hence I hope John won't mind my reproducing his email here.

John wrote:

I am possibly unusual in that I listen to both the 5 Live Podcast and the Naked Scientists one!

I take issue with your report in today's broadcast on the safety of flying during Covid. Your interviewee failed to consider one vital point which means that the thrust and conclusion are flawed.

By way of background my father died of Covid-19 in late March while in Tenerife. He us still there and I have, at some point, to deal with his Spanish affairs. I have therefore done a lot of investigation into the safety of flying, particularly as I have underlying medical issues.

Your interviewee mentioned the air filters on planes. After asking many times one airline eventually told me "All our aircraft are fitted with super-efficient, state-of-the-art ventilation and filtration systems to control air quality and circulate fresh air around the cabin every few minutes. These systems are similar to those you would find in hospital
settings and meet the highest standards of clinical hygiene."

So I then asked them what size the filters are in microns. Their response was "the Boeing requirement for a HEPA filter is at least 99.97% efficiency on a 0.3 micron DOP (dioctylphthalate, an aerosol used as a standard for testing) particles tested at the rated flow Per MIL-STD-282, Method 102.9.1, DOP-Smoke Penetration and Air Resistance of
Filters. The HEPA filters recommended in the Reference /A/Multi-Operator Message are rated to HEPA Class H13 (or higher)".

So I responded with the observation that as the Covid-19 virus is 0.125 microns or less then their air filters will be ineffective against it.

At this point the airline stopped corresponding with me.

But the point is that the air filters do not filter out Covid-19 but they do circulate the air every few minutes. Therefore if you have say 100 people who do not know each other in an sealed tube (aeroplane) for hours at a time then the risk is very high and not low as your report stated.

This was my reply:

Dear John

Thank you for writing, and for your careful listening. I'm sorry to hear about your father.

You're right concerning the sizes of the infectious particles: flu and coronaviruses are about 100nm (0.1 micron). However, the information that the airline has given you is not helpful because it did not address your question.

The short answer is that I can reassure you that the HEPA filters are actually very good indeed and in particular in the particle size range that includes respiratory viruses (like coronaviruses), and therefore their effectiveness at scrubbing viruses from air is not in question.

The more detailed answer is that there are two lines of evidence that support the effectiveness of the HEPA filters used on flights: 1) test data on particles and filter performance; 2) actual observed infection spread on flights and in other environments where this filtering regime is used. Obviously, 2) is affected by a range of factors other than just filter performance and therefore is a less stringent measure.

In terms of 1) this paper from NASA (2016) is quite technical but the text at the bottom of page 6 referring to the graph on page 7 is the crucial piece of data.

You'll see that the capture efficiency (blue line) for particles of the 0.1micron scale is nearly 100%.

https://ntrs.nasa.gov/citations/20170005166 - Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters and Packed Beds of Granular Materials

In terms of 2), this is observational data and WHO audits, which suggest that 70% of transmission cases are within 2 rows of an infected individual. Given how "noisy" these data are likely to be (allowing for factors like people wandering around, contact at the airport, in the toilets, at customs etc), this shows that the "on-board" transmissions appear to be well controlled by the ventilation system. Indeed, in situations that have been studied where aircraft have turned off the air systems owing to malfunctions, infection rates were much higher and the spread much wider.

I hope this goes some way to explaining what Julian Tang was aiming to convey.

Sorry, again, to hear about your circumstances and thank you for listening to our programmes.

Chris

17

Physics, Astronomy & Cosmology / If everyone in the world went swimming at the same time, would sea level rise?

« on: 04/09/2020 09:12:49 »

Great question from today's Ask! The Naked Scientists phone-in on 567 CapeTalk:

Jen asked, "if everyone on Earth waded into the ocean up to their shoulders at the same time, what would be the effect on sea level?"

I speculated that it would be tiny, compared with the huge effects of atmospheric pressure, temperature, tides, waves, winds and the vast size of the oceans compared with the people.

But am I right?

I have also offered to provide the calculations to work out the scale of the effect. This homework is due in on Friday morning next week. Who can help me?!

18

Physics, Astronomy & Cosmology / What causes the high-pitched sound when a knife scrapes across a plate?

« on: 28/08/2020 08:23:54 »

Sometimes, when cutting something on a plate, the knife or fork slips; this is accompanied by a high-pitched scraping or screeching sound that makes some people shudder.

What is the source of that sound?

19

Just Chat! / MOVED: Please delete

« on: 02/08/2020 10:33:07 »

This topic has been moved to Free Parking!.

https://www.thenakedscientists.com/forum/index.php?topic=80141.0

20

Question of the Week / MOVED: What should be done to avoid the next pandemic?

« on: 29/04/2020 08:10:24 »

This topic has been moved to COVID-19.

It is not a question of the week; please don't post general discussion topics here.

https://www.thenakedscientists.com/forum/index.php?topic=79425.0