1

Physiology & Medicine / Re: Acclimating to temperature: how do we get used to the temperature?

« on: 15/01/2025 09:28:05 »

There are a few factors to consider here:

We tend to dress, eat, drink and behave differently in anticipation of different weather and temperature conditions. The body adjusts metabolic rate (which burns calories to yield heat) as temperatures rise and fall, we also eat more when we're cold, and when we anticipate feeling cold so we wear more layers.

The nervous system is also acutely sensitive to change, but not to absolutes or steady states so much; this is nicely exemplified by this simple experiment you can try for yourself: https://www.thenakedscientists.com/get-naked/experiments/strange-temperatures
 
So, in summary, you neurologically "get used" to a temperature quite quickly, and this is reinforced by underlying physiological and behavioural changes that enhance resilience.

2

Physiology & Medicine / Re: Can Coffee Or Tea Ever Really Go Bad?

« on: 03/10/2024 08:58:55 »

Different foodstuffs rot at different rates.

Dried materials - like tea and coffee - will deteriorate more slowly, but they will still perish. Volatiles in the material will slowly be lost; also, ongoing chemical reactions between the entities they contain will change the flavour and palatability over time.

Wine, for example, continues to evolve in the bottle. The thousands of molecules in the liquid react to produce new species. This alters the character of the beverage over time. This is why some wines have a short "bottle age" while others "age well".

Medicines are similar. Some are very stable molecules that will last forever. Others are more fragile, and or mixtures that may react or decay, potentially affecting potency.

3

Plant Sciences, Zoology & Evolution / Re: What is the Origin of Naked Clams (Shipworms)?

« on: 03/10/2024 08:49:50 »

I just read the piece from the placard that says Columbus infested Europe by bringing the pests back with him aboard his surviving vessels.

This seems unlikely to me. Surely a log or two must have made it across the Atlantic to Europe from time to time?

4

Plant Sciences, Zoology & Evolution / Re: What is the Origin of Naked Clams (Shipworms)?

« on: 03/10/2024 08:47:41 »

Thanks for that nice bit of history, Evan.

In the interview, David Willer does say that most of the shipworm / naked clam activity is centred on mangroves, which is presumably their evoluntionary niche, together with any bits of wood that washed out to sea. We just provided them with an even more attractive mobile campsite when we built boats.

I'd also hazard a guess that the woods used for ships are possibly more susceptible than evolved marine species like mangroves, which will have developed some element of resistance, rather like native Australian terrestrial trees have evovled ways to fend off termites and other wood-boring nasties.

5

Cells, Microbes & Viruses / Re: How can I remove an unidentified yellow slimy organism from human skin?

« on: 03/10/2024 08:09:29 »

Can you post a picture of what you are referring to? A picture paints a thousand words, after all.

6

Physiology & Medicine / Re: What isotope to commit murder undetectably?

« on: 14/06/2024 15:21:56 »

Thanks, all, for these helpful suggestions, which I shall pass on.

Incidentally, the point about firing an X-ray beam through the wall made me think of this trip we made to UCLA 16 years ago to visit Carlos Camara, who'd recently published the findings that unreeling sticky tape in a vacuum produces a beam of X-rays through triboluminescence.

His apparatus was pointing at the ceiling, prompting me to ask, "who is on the floor above?"

We all looked skyward and someone said, "not sure, but by now they're probably infertile!"

https://www.thenakedscientists.com/get-naked/experiments/glowing-tape

7

General Science / Re: Do germinating tomatoes kill off competing plants?

« on: 12/06/2024 07:30:23 »

Nice video and an interesting observation.

Yes, this is possible. Some trees - acer family - release toxins that suppress the growth of rival species, ostensibly to give their own offspring a better chance.

I suppose there are two things possibly happening here with the tomato: one is that the dominant plant does release things locally that destroy the competing plants. The other is that the dominant plant hungrily devours all available nutrients, and water, and the smaller plants cannot compete. So once they run out of supplies from their seed, they perish. Or it could be both.

8

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...

9

Technology / Re: Does regenerative braking have a hazardous complication?

« on: 29/04/2024 10:01:06 »

I completely agree. Definitely safer if the car behind knows you are slowing down.

That said, in my previous car, and in my wife's present (non EV) car, just taking your foot off the accelerator (and hence slowing down) does not trigger a brake light warning, although the rate of deceleration is obviously considerably slower.

Maybe it's a rate thing? Is there a standard set by the industry to address this? ie slow down at more than a specific rate and that's regarded as "braking" and needs a warning light?

10

Technology / Re: Does regenerative braking have a hazardous complication?

« on: 28/04/2024 11:52:05 »

but neither function appears to activate the rear brake lights...

My car (fully EV, Polestar 2) can be set to one pedal or two pedal driving; the former makes maximum use of regenerative breaking and I barely need to use the brakes. It definitely puts the brake lights on in this mode.

So maybe this is a foible of some makes?

11

Physiology & Medicine / Re: Why did I awaken unable to speak?

« on: 21/04/2024 22:19:52 »

You might have aspirated (inhaled) a small amount of the regurgitated material. This is acidic and tends to be very irritant to the airways, particularly the upper airway and vocal folds; stimulation of the nerve supplying the vocal cords provokes a profound cough stimulus; the body interprets the irritation as an inhaled foreign body and the coughing is intended to expel it.

When this is happening, it often causes vocal cord spasm, making the voice weak, reedy or "thin" until the attack settles.

I suspect this is what happened.

12

Technology / Re: What are the best options for webstore Credit Card processing?

« on: 24/05/2023 08:30:32 »

I wonder how long it will be before another poster pops up with a magical solution and a link to their product that directly addresses this user's enquiry? Won't that be a coincidence...

Sorry if I sound cynical and you are a genuine poster, but we see this so often that I'm highly suspicious of posts like yours. If this is the case, I apologies for my glib reply.

13

General Science / Re: How does ChatGPT work?

« on: 18/05/2023 09:13:18 »

In case you did not catch it, we recently published an episode of the Naked Scientists podcast on Artificial Intelligence and chatGPT, which might be helpful.

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Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 17/05/2023 17:28:54 »

SERVER MIGRATION UPDATE - May 2023

Hello everyone. I wanted to bring you up to speed on what's been happening in the background recently.

After 17 years, the company that had hosted us through most of this site's lifetime were taken over by a new kid on the tech block. The "new broom" decided to make a clean sweep of existing relationships like the one we had and asked us to pay ?25,000 per year for our webservers, or pack up and go. I attempted to negotiate a bit, having pointed out that they'd had 120M+ brand impressions through us just on our podcast, but to no avail. Their best offer was still stupid amounts of money for what amounted to an annual electricity bill (the servers were already set up and running and had cost nothing in maintenance for a decade).

Unsurprisingly, I decided to exit and set up our own hosting from Naked Scientists Towers. This has involved quite a bit of behind the scenes work to migrate everything across and make it work stably; I was especially worried about this forum because it's notoriously fickle and doesn't like to budge from its home.

It looks like it's moved across okay, and I hope the user experience is tolerable. I'm still doing a lot of optimisations behind the scenes now to make things work better. There is always a bedding in phase with new setups where one strives to find the config "sweet spot" for the stack that's running. We're just at the start of this process at the moment, so it will hopefully continue to improve from hereon in.

My plans for this year are to upgrade this forum to newer iterations of the software, which should make it run more slickly, grow our user base more, and upgrade the theme to a more contemporary look. Suggestions, though, for the latter in particular, would be most welcome. And any coders and web gurus out there who would be willing to help, do please drop me a line.

Meanwhile, thanks for your energy and contributions, especially to the moderators!

Chris

15

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

« on: 02/02/2023 17:08:53 »

Dare I ask why this phenomenon occurs?

16

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

« on: 02/02/2023 17:07:50 »

There are legends about spooks who could read the data previously stored on a hard-disk, by reading the stray data "between" the tracks.
- Hence the idea of overwriting every sector with random data, multiple times, approaching from multiple directions, to also overwrite the "stray" data between the tracks.

I do not know whether the spook art has progressed to the point of sawing open the chips and counting the electrons on an EEPROM NAND gate, and determining whether that cell previously contained a 0, 1, 2, 3, 4, 5, 6 or 7 before it was overwritten
- I am sure that spooks would attempt this procedure if they had the opportunity to read the guidance software of a missile - before it has been erased.

Overwriting the every sector multiple times will cause wear on the SSD - but apparently they are rated at 100,000 write cycles, so not too much wear.
- As sectors wear out, they are put on a "do not use" list, and the result is that the disk capacity slowly decreases (and you might lose an occasional file which suddenly couldn't be recovered)
- I suggest that for an SSD, it is sufficient to use a tool which overwrites every sector once

See (other brands are available): https://www.kingston.com/en/blog/pc-performance/nand-flash-technology-and-ssd

That was my view, and what I decided to do; a write-once is probably sufficient.

17

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?

18

New Theories / Re: New theory of social evolution and social structure

« on: 31/01/2023 11:44:22 »

What's the question you are asking?

19

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?

20

General Science / Re: Do we sense temperature?

« on: 04/10/2022 12:11:03 »

We sense temperature, and heat-sensitive neurones fire at a rate proportionate to the temperature, notwithstanding effects of adaptation / accommodation.
.