## Stop Trusting Everything You See

### Background

Everyone who comes on this blog often knows that I’m a huge fan of Prof. Rischard Wiseman. If you don’t know that, well, I urge you to check out every other post where I’ve mentioned him (Yes, he’s the same man who makes videos for the YouTube channel 59 seconds). The man certainly knows how to play with your brain. And once again he has blown my mind with this amazing optical illusion that he shared on his blog.

This is probably the best optical illusion I have ever seen. That is because, it’s somewhat like the Mc Gurk effect (do check it out too) – in a way that, it is one of those illusion where even after you learn about it, you still can’t see through it. I mean, it will continue to fool your brains, even when you know the trick. It’s an eternal magic trick. Enough of the build up. Now, let’s see what this illusion really is…

### Wash your eyes if you have to

In the image below, you’ll see a pinkish swirling image and inside it you’ll see that there are green swirls and blue swirls embedded. What if I tell you the green and the blue you see are the same colors? Just because I’ve written something that’s completely opposite to what you see with your own eyes, you’ll probably laugh on my face and call me mad. I did that. I trusted my eyes more than any one else’s word. So I had to verify it…

### The Proof

Ok, if you take my word for it, fine. If you don’t believe me, you could use a simple image editor, pick colours and check. Both the colours you see here, green and blue, have the same hexadecimal value: #00ff96.

Another thing you could do is, download the image, zoom it to a great extent, such that both the colours that you see are in the same frame and you’ll see that the colours are actually same. Here’s a picture of that zoomed part…

Here’s an image I created where we have the #00ff96 coloured square overlapping the seemingly blue and green parts. If you, cover everything except the topmost corner first, look at it carefully, and compare it with the bottom-most corner, you’ll see that the colour of the square block perfectly matches that of both the “blue” colour and the “green” colour in both areas. And it is the same block.

The several other blocks in the middle are for you to remain sure that the colour of the block doesn’t change in between.

There’s another image in which it works…
Even here the blue and green colours are actually the same colours…

## The Blue Blood of a Horseshoe crab is Precious

### Not-so-good Bunnies

Several years back large colonies of cute little rabbits were being maintained by pharmaceutical companies. These rabbits were used to find contamination in solutions that would be used to treat human beings. If the rabbits fell sick due to fever after being injected, the solutions were labeled as contaminated and were not injected into humans. If the rabbit had no fever after 2 days, the solution was deemed clean and could be used on humans.

However, pharma companies hated this process – not because they felt bad about harming cute bunnies, but the process was expensive and took about 2 days to give results.

### A new discovery

A few years later, a scientist named Fred Bang was studying the circulatory system of a horseshoe crab – half a billion year old specie. He accidentally discovered some amazing properties of the horseshoe crab’s blood when one of his crabs died because its whole blood turned into a semi-solid mass.

He found that when the crab’s blue colored blood came in contact with a certain kind of bacteria, it got clotted into a semi-solid mass and completely trapped the bacteria.

And ultimately with the help of a scientist, Jack Levin, he developed a  process that could be used to detect bacteria contaminated solutions (contaminated with endotoxin). This process proved to be a boon to us humans.

### The replaced test

Today the old bunny test has been completely replaced. Pharmaceutical companies love the new test because it takes about just 45 minutes to complete and costs much lesser.

Every year thousands of live Horseshoe crabs are made to bleed blue to take advantage of their blood’s unique properties. About 30% of these crabs die. The miracle blue liquid can detect contamination in solutions that are extremely tiny (even if the contamination is as tiny as some parts-per-trillion).

The several liters blood extracted from these live crabs is used to save human lives by protecting them from contaminated solutions.

Every single person who has ever had an injection, has been protected because the blood of a horseshoe crab ensured that you got clean injections. Had there been no horseshoe crabs, we’d have been killing bunnies. Salute to the crab.

## Sun’s Green Flash

###### By Anupum Pant

More often while setting than rising, if the conditions are right, a part of the sun (on the top) can appear green. This happens for very short interval lasting for about 2-3 seconds and is considered a rare phenomenon. Since it is green and lasts for a very small interval, it is also called the green flash, emerald flash or green ray. If you have ever captured it or plan to do it in the future, do share your results with me through mail/twitter. [See the animation] [Real GIF]

### What does it look like?

Sometimes the sun’s rim can appear green (in optically zoomed images). Otherwise, when the sun is set, for a brief moment, it appears as if a part of sun has separated from the main body and has turned green. It is usually seen as a horizontal line, like in the video below. But, a few lucky ones have captured complete green auras too.

### Why does it happen?

The sun gives out a white light, which contains all the colors – Green is one among  them. Normally, our eye isn’t able to resolve the separate colors and sees them as a mixture which is white. When the sun sets, our atmosphere acts like a prism and bends the colors. A few colors get bent more than others. For example, green bends more than red. As a result the two colors get separated enough to be resolved by our eye. But the right amount of bending happens only if the atmospheric conditions are right.

In extremely rare cases, blue or violet flashes have been reported. [image]

For a detailed explanation you can go through this – [Geometric Optics of Green Flashes]

At poles where the sun moves in a different manner, probably the green ray can last much longer. Admiral Richard Byrd has claimed to have seen this green flash for 35 minutes while on an expedition to Antarctica.