The Leidenfrost Effect has nothing to do with frost or the Dutch city of Leiden. Rather, it’s named after a German physicist, Johann Gottlob Leidenfrost, who published a scientific paper on the phenomenon back in 1756.
You can witness it for yourself, if you sprinkle water onto a really hot frying pan or the rings of an electric cooking hob. That moment when the hob gets really hot and water droplets go whizzing off as if on a cushion of air is the Leidenfrost effect in its simplest manifestation.
It usually occurs when the surface temperature that the water droplets touch is greater than 200C. Past the Leidenfrost point, the bottom surface of the water droplet turns to vapour so quickly that it creates a little insulating pocket under the drop. Pressure from the vapour keeps the droplet aloft, like a tiny little hovercraft.
As it scoots around on the heated surface, molecules of water keep turning into vapour from the underside of the droplet, in a process known as film boiling. But the part of the Leidenfrost effect that’s the most interesting to scientists is how the droplets move.
With so little friction between the liquid and the surface, even slight disturbances in the vapour pockets – caused by escaping molecules of gas – are enough to send the droplets ricocheting all over the place. And the bigger the droplet, the less stable its vapour cushion is, so the more it moves around.
It’s speed, if controllable, could be used in various different applications, from pharmaceuticals to ink-jet printing. That being said, the temperatures required for are so high that it could prove hazardous and costly in terms of heat generation.
A radical new approach to fighting cancer, which might open the doors to treating other aggressive diseases involves doing something that would probably go against the grain and is completely counterintuitive to most people reading this.
Drs. Carl June and David Porter from the University of Pennsylvania, and their colleagues, have embarked on a new form of treatment for cancer patients which involves injecting them with a modified form of the HIV virus which zero’s in and kills cancer cells.
The trials have been carried out on patients who are classified as terminally ill and whom have no other avenues of treatment open to them. This is their ONLY hope.
The video shows a patient, a young girl called Emma, who has suffered from leukemia for many years. She’s had to endure it coming back TWICE. Her parents were effectively looking for a miracle.
The T-cells are collected and infected with the modified HIV virus. This genetically changes the T-cells which are now reengineered to scout in the patients, look out for and ultimately kill the cancer cells within a patients body. The modified HIV virus has been changed so that it can no longer cause disease, but it still retains the ability to reprogram the immune system. The result being that it attacks the cancer cells.
This treatment is cutting edge and it has not yet been developed to work on everyone.
Emma has gone on from strength to strength, beating leukemia, hopefully for good this time.
We Irish love our spuds. But if you live in a typically large Irish family, it means there are quite a lot of the buggers to peel when preparing dinner. Which could take an awfully long time…..until now!
So when you’re preparing dinner next Sunday, take a look at this YouTube video which shows an ingenious way how to peel a bag of spuds in 60 seconds using a hose, a bucket, and an industrial drill.
Richard (Ric) Kaner has always wanted to be a scientist, with the end goal of discoverying something that would change and revolutionise the world. Guess what, it looks like he’s achieved his goal.
He and his colleague, Maher El-Kady, set out to find a new way to make graphene, the thinnest and strongest material on earth, the discovery of which led to Andre Geim and Konstantin Novoselov at the University of Manchester winning the Nobel Prize for Physics in 2010.
But as with many things in science, the search for a particular solution resulted in them stumbling upon a completely new discovery and application never even thought of before. The result? Kaner and El-Kady have discovered a new way to power the world!
To call this revolutionary is probably the understatement of a life-time! And the applications for graphene’s new discovered applications as a super supercapacitor now mean things like electric cars, cleaner energy and less pollution from old chemically based batteries are all possible. It’s like generations version of the invention of the incandescent light-bulb.
Watch the video to learn a little more about what graphene is, and how it will change the world we live in.
Boyan Slat, a young Dutch aerospace engineering student at TU Delft, and a keen S.C.U.B.A. diver has managed to come up with, what seems to me, to be an elegant solution to cleaning up the worlds ocean’s from the debris and detritus that we humans have simply discarded and polluted during our everyday lives, whilst making a tidy profit at the same time.
Millions of tons of plastic kill ocean life and poison food chains, accumulate in areas such as the “Great Pacific Garbage Patch”, which are located at the top layers of the ocean’s five gyres, and Boyan sees opportunities to combat this. Combining environmentalism, creativity and technology to tackle this global issue, and at the same time, creating a new money spinning industry, he believes current prevention measures have to be supplemented by active removal of plastics in order to succeed.
His concept, called Marine Litter Extraction, won the Best Technical Design award 2012 at the TU Delft.
While researching ocean plastics during his school holidays, he analysed various fundamental topics (including particle sizes, plastic/plankton separation and the amount of plastic in the oceans), leading up to the first realistic concept for cleaning up the world’s oceans. Take a look at the video to find out how he proposes to do it.
And if you combine Boyan’s capture concept with Akinori Ito’s plastic recycling idea, mentioned in a previous Science Saturday post, then you have the makings of something truly great for the environment, whilst making a few quid on the side too!
Fracking. It’s all over the news lately, and almost everyone I speak to about it hasn’t the faintest idea about what it is and why it’s so controversial. And many of them naively think that it’s the holy grail to cheaper energy and saving themselves a few bob in the long run. The reality is very different.
And so to help you understand firstly what fracking actually is, and secondly why it’s so dangerous, the guys at Kurzgesagt put together a great no-nonsense video which explains everything.
The two things that scare the living daylights out of me about fracking are these.
1. Essentially, oil and gas companies, who only care about profiteering, and have historically a dismal record when it comes to even bothering to think about the environment, have been given unfettered access to pollute the ground we grow crops on and the water we drink. They care not a jot if someone accidentally fucks-up, and given the recent disasters that happened (Gulf Coast oil spill being the biggest of late) nobody went to jail and it boiled down to a question of monetary compensation, but no real changes were ever made either to the engineering used, the safety reviews to be conducted or even if it made sense to continue drilling in such deep wells, given the hazards and safety issues.
2. We are already over populated as a planet, straining to feed the population with our resources. And the next precious resource that will be the cause of wars across the globe will be WATER. So what happens if countries, such as those in the EU or in North America, who today have no issues or worries about their water needs suddenly find themselves without clean safe drinking water, because they let some oil and gas numpty fracking the shit out of the soil below and it’s now all irrevocably polluted? Will we be going to war just to get enough clean water so we can still enjoy a nice cup of tea?
Do yourself a favour, and inform yourself, petition against and fight to get rid of fracking. It’s a short-sighted energy bubble which will have VERY long term detrimental affects for the environment and everyone living in it.
This is SO cool, I was thinking of holding it off for a Science Saturday article…..but I just couldn’t wait!
Almost every western industrialised nation – except perhaps for the USA – has embarked on various forms of large scale recycling initiatives. Glass, paper and tin cans are regularly separated. But nobody has come up with a useful way of recycling plastics. Plastic takes a LOOONG time to decompose. They are not naturally biodegradable, and they consume a lot of space in the worlds rubbish dumps. What’s even worse is that all plastics are made from oil! Think about that for a second. We consume oil for getting us from A to B, in growing and transporting our food and in packaging that food in plastic containers for consumption at a later date. Our food is literally covered in oil.
But Japanese scientist, Akinori Ito, from Blest Corporation, has come up with an amazing, yet simple solution which not only tackles the problem with recycling waste plastic, but could also help resolve our dependence on the ever diminishing fossil fuels. His novel and simple solution is to heat the plastics and melt them back down to their oil based constituents. This oil can then be refined for use in home heating, cooking or for your car and truck.
The weird thing is that I only came across this now (thanks for sharing it Dawn), but the video was made back in 2010. I checked various “hoax checking” sites and they all confirmed its validity. So why is nobody else trying to make bigger versions of his machine? Well, there are larger installations already up and running. But as you can imagine, they are predominantly based in poorer nations who do not have a large oil and gas lobby group which would railroad such a project.
As with anything, you need to put energy into something to get energy back out. The beauty of this is that you could power it via wind or solar power, melting the plastic down and converting it back into oil. You would actually help the planet!
Why our supposed eco-friendly soundbite loving politicians here in Europe haven’t done anything about rolling this across Europe is beyond me. But I would love to get my hands on one of these for myself.