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Cells, Microbes & Viruses / Could a virus or bacterium survive inside a rock?

« on: 23/03/2018 04:12:49 »

So, some viruses (and some bacterial spores) are known to survive for long periods in the environment and be resistant to the elements. Would it be possible for a particularly hardy pathogen to land on some sediment, become incorporated into the rock as the sediment is compacted, spent thousands of years protected inside this rock in a dormant form, and then finally be released into the environment when the rock breaks apart (erodes, falls off the side of a cliff, earthquake etc.) and go on to infect a new host?

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General Science / Why do I get stuck trying to dodge another pedestrian?

« on: 11/05/2017 08:48:29 »

Fairly frequently, while I walk innocently down a busy street, I find myself face to face with another pedestrian directly in my path, who is trying to walk in the opposite direction. Why is it that, when this happens, we find ourselves in a vicious (and socially awkward) cycle of trying to dodge and out-dodge the other person by stepping side-to-side, while remaining completely in the other person's way?

For me, this seems to go on for 4-6 dodges, spanning several seconds (but feels like an eternity). Both parties seems perfectly aware that this is happening, but are yet helplessly trapped until either our dodging attempts eventually fall out out of sync, or until someone consciously stops dodging, and we are free to continue walking forwards. What is going on here?

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Physiology & Medicine / Do humans have primitive 'venom' glands?

« on: 28/10/2016 15:24:46 »

Sometimes when I yawn, I shoot saliva out of both parotid (salivary) ducts at high speed like some sort of venomous snake. Recently, I asked my close friends about this, and so far, I have found seven friends who also do this when they yawn. So not just me!

Do other people do this? Is there a purpose for humans to suddenly eject saliva from their mouths while yawning? Or is it just an unfortunate 'side-effect' of opening ones mouth to its fully aperture?

Given that many species of venomous snakes produce their venom within modified parotid glands and eject it through the modified ducts, could this be the human version of this defense system?

Or just a weird and socially-unacceptable bodily function?

Cheers.

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General Science / Fishy forensics: Could a hook rust while inside a fish?

« on: 17/03/2016 10:13:29 »

Some of you might remember me. I haven't been on here in a long long time!

Multidisciplinary question for you all. A bit of general chemistry, a bit of physiology, a bit of biochemistry, and a bit of fishy forensics. I dabble a little in all of the above, but not enough to piece it all together.

Background:
- I saw a fish today as a patient. A fiddler ray, in fact. It was a very sick fish, so unfortunately it had to be euthanised and undergo a post-mortem examination.
- Although, not the main reason it was so sick, this ray was found to have a fish hook basically floating freely within her coelome (the main body cavity). It was a very rusty hook.
- We know for certain that she has had no exposure to fish hooks in the last 8 years, since she lives in captivity. However, prior to 8 years ago, she lived in the wild, so probably encountered the fish hook there.
- Given that the hook was not in the digestive tract, and there was no other point of entry found, we assume that it once entered the mouth, then the digestive tract, then perforated the stomach/intestine and made its way into the coelome, but (amazingly) healed up and did not die in the process.

Question:
- Could a brand new fish hook rust inside either the a) the digestive tract or b) the internal body cavity of an animal? Are the necessary conditions for metal corrosion available within an animal (ie. oxygen, acidity etc.)?
- Alternatively, did the hook need to have rusted BEFORE it was ingested (eg. sitting on the seafloor, attached to another fish etc.)?

Any brainpower would be greatly appreciated!

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Cells, Microbes & Viruses / Is it safe to eat from the sandwich toaster at work?

« on: 03/02/2011 10:38:32 »

Hi everyone! I finally have internet again (whew!) after moving house and starting my new life as an employed person.

I was sitting in the staffroom at work the other day during lunch and staring at the sandwich toaster, as you do. It seemed to contain small remnants of every ingredient from every lunch it had ever produced. I'm pretty sure the entire food pyramid was there in various burnt, melted, and squashed form. So my question is:

Would I be better off using the sandwich toaster as is, risking eating bonus bits of really old, repetitively cooked food, or should I clean it first with that semi-disintegrated sponge in the sink while the toaster is cooling down from its last use?

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General Science / How much would it have to flood?

« on: 12/01/2011 09:07:31 »

In light of the currently flooding situation in Queensland, Australia:

If I were to stand in a given location during biblical times and the land around me began to flood in a circular pattern, what sort of area would the floodwater have to cover before I would be convinced that the entire world had flooded? Assuming I were a fairly reasonable person with good eyesight and an ability to float...

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Technology / How do they remaster old movies?

« on: 02/04/2010 03:54:04 »

How do they take old movies on film and make them look all new and shiny again? I have an image of someone sitting at a computer fixing the pictures frame by frame...but that seems a little time consuming.
So how do they do it?

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General Science / When can I turn a bottle upside down?

« on: 18/08/2009 10:35:13 »

Ok, context: I've recently starting doing my clinical rotations at our university's veterinary teaching hospital and around at other veterinary clinics. I've found that certain drug bottles (of various forms and sizes), for single-use, are designed so that you're meant to break the top off and turn the whole bottle upside down before drawing it up (or rather 'down') into a syringe. And it is usually much easier to do it this way than to draw it up from above the bottle. The trouble is, it never says to do it that way on the bottle and I am left reluctant to invert the bottle in case the entire contents pours straight out.

Question: Is there some kind of rule I can use to judge whether or not the liquid contents of a bottle will stay in the bottle if I turn it upside down (eg. Size of the opening? Size of the bottle? Relative size of the opening compared to the volume of the bottle? Compared to the diameter of the rest of the bottle?) without having to risk, say, dosing the floor with morphine?

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General Science / Why do blind people wear sunglasses?

« on: 08/07/2009 10:48:28 »

I may just be very ignorant here but I've never quite worked out why blind people often where dark sunglasses?
Is it to block out light from reaching their eyes or to stop people from seeing their eyes, and why?

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Physiology & Medicine / How does someone get unfit?

« on: 08/07/2009 09:59:17 »

Twice every year, I suffer from Should-be-studying-for-exams-exercise-reduction Syndrome, ie. for about 3 weeks I am forced to slightly reduce the amount of exercise I get each day. Trouble is, I then have a terrible time the next week or so trying to regain full fitness and feel like I have to work a lot harder to do my regular run.

What changes occur when someone reduces the amount of exercise they do (without ceasing it entirely)?

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Plant Sciences, Zoology & Evolution / What distance does a beehive need to be from a toxic plant? And bee preference..

« on: 08/04/2009 12:13:37 »

Various plant toxins have been reported to transfer from the nectar of toxic plants into honey and, in some cases, may have detrimental effects following the consumption of the honey. Examples of such toxins include pyrrolizidine alkaloids (from Echium, Heliotropium, Senecio etc.), grayanotoxins (rhododendrons) and a number of compounds produced by oleanders.

2 part question:

1) If one were to set up a beehive to make honey, what would be the minimum distance from a field full of toxic plants they would need to put it to ensure that the bees do not collect any of the nectar from those plants?

2) Hypothetically, if a field containing only a ‘typical’ non-toxic flowering plant was situated directly adjacent to one containing only a ‘typical’ toxic plant (or a random selection of toxic plants) and the beehive was set up right between the two (both fields in full bloom, same density of flowers, no predators in either field, no field will overgrow the other) which field would the bees tend to feed in more?
eg. the non-toxic one to minimise any toxic effects on the bees, the toxic one to maximise the toxic effects on potential honey-stealers, or no difference?

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General Science / Will I lose more heat by rolling my sleeves up?

« on: 12/01/2009 01:08:16 »

Suppose I am wearing a long-sleeved jumper when the day starts to get uncomfortably warm, and a somewhat unsightly Bee Gees t-shirt underneath prevents me from removing the outer layer.

If I want to lose the maximum amount of heat while still wearing the jumper, should I roll my sleeves up to help lose some extra heat from my lower arms but make a thicker layer of jumper further up with possibly less ventilation, or should I leave the sleeves long and at an even thickness across the whole arm?

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Just Chat! / Pickpocketed!

« on: 21/11/2008 09:10:53 »

Just thought I'd have a little whinge about my day and hopefully make myself feel a bit better.

On the way to my 7th exam in 2 weeks today, I found myself blocked up behind what appeared to some sort of large male choir that had set up a prank to actually get in the way of everyone in the underpass and sing about it. Not that the singing was bad. The whole idea might've been half funny, if I wasn't in a massive rush to a massive exam. Frustratingly, I had to shuffle along behind them at snails pace until we got through to the other side. Anyway, I missed the tram, missed the connecting tram and ended up arriving about 10min late to my exam, almost in tears.

After the exam, I thought I'd go for a wander through some shops to relax before going home to study AGAIN! Anyway, I was in a clothing shop when I felt something moving around from my backpack. I thought it was a bit strange and checked out my bag. The outer zip was half open and I saw a woman hanging around behind me. Stupid, naive, over-trusting little me gave her the benefit of the doubt and let it go. Thought maybe she'd just inadvertently bumped into me. I checked my wallet was still there and pushed it deeper into my bag and zipped it up again. A few minutes later, I saw the same woman hanging around me again and her friend nearby. I made a mental note to be extra careful and avoid her, but in my post-exam not-quite-conscious state, I didn't think I needed to actually take my wallet out of my bag. Checked out my bag again a little bit later. Open zip, no wallet, no more woman hanging around.

Had to report it to the shopping centre security office, to the police station, cancel all my cards, and had to call the university to organise some proof of ID for my exam on Monday (I can't sit exams without ID). Now I'm going to have to drop into uni to pick up a temporary ID on Monday morning and before going to the exam venue. What’s worse is that I was actually thinking of moving my ID card to my pencil case earlier before I forgot where it was. Oh yeah, and I’m now 20 dollars poorer. Sucks.

I’ll live though! Just don’t know why I feel the need to see the best in people. Not a particularly useful skill, is it? Urghh.

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General Science / More likely to fly in or out?

« on: 17/08/2008 10:12:05 »

At times I might find a fly (sometimes even a small bird) inside a room, perhaps trying to find its way out of the room without any luck. Any attempt to show it the way out (through a doorway or window) is usually of little success, at which point I resign to having to put up with a buzzing sound in the room for at least a while longer...or in the case of the bird, catching it and taking it outside. The question: Is there any difference in the likelihood of a creature flying into a room compared with the likelihood of it flying out of the room?

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General Science / Why is milk white?

« on: 20/05/2008 03:03:15 »

Why is it that milk straight from a cow is yellowish, but cow's milk from the shop is white? Do they actually deliberately take the beta carotene out of it...is it just denatured or reacted with another substance during the processing...or is there another explanation?

What do you think?

SqD.

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Just Chat! / What is so scary about spiders?

« on: 11/05/2008 06:47:06 »

To any of you out there with a fear of spiders, I was wondering:

What specifically about spiders give you the creeps, and to what extent? (I'm not having a dig at you...just curious!)

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General Science / Mosquitoes!

« on: 09/05/2008 14:40:40 »

Well, everyone else seems to be talking about mosquitoes, so I thought I'd start a thread about them too!

Nah, couldn't help noticing a sudden surge in mosquito questions and topics around this place. Is it the season of mossie love in the north?

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General Science / Are the lottery machines really a lottery, or less down to chance than we think?

« on: 13/04/2008 04:55:03 »

Wasn't sure if I should put this in General or Chat, but I can't help thinking that theoretically, it'd be relatively simple to control which balls are drawn from the pool in most television lottery set ups. I don't watch these a lot but from what I've seen, it seems like they start with the balls in a FIXED rack, which roll into a FIXED container (usually a spherical one), with a mixer with FIXED arms moving at a constant rate around a single axis.

So as long as you start the arms of the mixer at the same position each time, and time the drop of the balls the same, doesn't the only variable become the position of the balls in the rack (ie. if the first ball drawn was in column A, row 2 and the second ball in column B, row 3 etc...whichever balls are in those positions in the next draw will be first and second again)? And then you can put whichever balls you like into the positions you know are going to result in the ball being drawn?

Does that make any sense? Or am I missing something?

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Just Chat! / Vent...Grrr.

« on: 06/04/2008 09:32:57 »

Sorry, just had to get this off my chest:

A certain juice company in this part of the world has decided to market a new juice that contains "50% less sugar"!. Funnily enough, it also contains "50% real fruit juice" and half the vitamin C. OH REALLY?! You didn't happen to just dilute regular juice with water to try to sell it off as a healthier alternative did you? Grrrr!

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Just Chat! / Where do I write in a greeting card?

« on: 30/03/2008 05:53:11 »

Nothing to do with anything science, but hoping someone might help me out here... The printed text inside a greeting card is almost always in the middle of the right side. Particularly when the text is the punchline to the joke on the front of the card, should I keep all of my own writing below the text, leaving a huge space at the top...or write both above and below the text and risk distracting the reader's attention from the punchline? I could possibly write on the left side of the card, but it doesn't seem quite right to me.

...or am I just thinking about this too much?

What do you guys think?