science with slightly more dimensional analysis

Put simply, the Earth is approximately spherical, and anything trying to tell you it is literally shaped like a potato is wrong, because the potato shape is just a map of the Earth’s gravitational field.

The planet's shape is a bit thicker round the equator and slightly flattened at the poles, as tends to be the case for spinning objects, but it's a lot closer to spherical than its gravitational field.

Hi there. It seems you've got completely the wrong end of the stick. I was not trying to contradict anything, because the simple fact is that the Earth is not lumpy. Presenting a geoid as an exact representation of the Earth's shape is misinformation and I have not misunderstood anything. I provided an explanation of what exactly a geoid is and why the Earth is not shaped like a geoid in my original post, but let me go into a bit more detail:

As I stated, geoids are not actual representations of the Earth. Putting aside the colouring indicating levels of high and low gravity, the shapes are computer models of a mathematical abstraction. The geoid is a model of the Earth neglecting influences other than gravity and rotation. (This means we get rid of the tides, which is perhaps why google reverse image search thought the gif was an Earth without water.) A geoid could not physically exist as a planet because it is an idealised and simplified shape and neglects a lot of real influences on a planet's structure.

Anyway, because the geoid's shape is strongly influenced by the Earth's gravitational field, the more elevated regions do tend to correspond to areas of higher gravity, which is why it is informative to present information about Earth's inhomogeneous gravitational field on a geoid instead of a more literal sphere.

So in summary, the gif in the misleading post is not a representation of Earth's true shape, as it suggests, or a water-less Earth, as google reverse image search suggests, but a geoid. The Earth is not the same shape as a geoid.

A lot of people have been mislead by a post that talks about the "lumpy" Earth, and unfortunately it seems that people genuinely believe the Earth is this shape. As one person pointed out, we have images of the Earth from space, and while it would be disingenuous to refer to it as a perfect sphere, it very much is spherical. A rudimentary reverse Google image search tells me that the image in the misleading post is a simulation of the Earth without water... which is just plain wrong.

In fact, the shape you're seeing is a geoid, which is a simulation of what Earth would look like if you neglected the influence of anything other than rotation and gravity. A geoid is a dynamic equipotential surface, which means that every point on the surface has the same gravitational potential.

Since it was recently NASA's Astronomy Picture of the Day, this seems like a good opportunity to talk about a geoid that is something more than a context-less gif: the Potsdam Gravity Potato, pictured above. It's the result of efforts by a group at Helmholtz Centre Potsdam to create a highly detailed map of the Earth's gravitational field. Like in a heat map, red elevated levels indicate stronger gravitational effects, and depressed blue levels indicate that they're lower. The potato-like shape occurs due to the Earth's uneven gravitational field. This is why high places such as the Himalayas coincide with local maxima on the geoid—but of course not all maxima and minima are the result of noticeable physical features; the Earth has inhomogeneous variations in its density, which account for much of the gravitational difference.

I was asked whether ebooks cause more eye strain than books. Short answer yes. Long answer is ... the rest of this post. I mean really it's these kinds of seemingly innocuous questions that can end up revealing a lot of strange confusing things about reality, and research is nowhere near finished on this topic.

Jeong H. (2010) has this delightful review in his background section:

"Cushman (1986) found that visual fatigue is significantly higher when reading texts on a screen than on paper. In the current stage of technological development, the display of text on computer screens has been found to have a negative impact on surface legibility (Dillon, 1994). Texts and documents on screen have a lower surface legibility than printed documents. Macedo-Rouet et al. (2003) noted that students felt much more tired when reading on screen; this may be because of the display contrast and resolution of an e-book. Kang et al. (2009) conducted an experiment to measure students’ eye fatigue and found that reading a p-book caused less eye fatigue than reading an e-book. In their study, the authors concluded that the eye fatigue from an e-book was due mainly to the low display contrast and resolution of the on-screen text."

The actual experiment determined visual acuity via a CFF test (what frequency does a blinking light look continuous). They found after reading a book it was reduced by 1.63 Hz; after ebooks it was reduced by 3.04Hz average. Cutely enough, this was done by testing 56 year 6 korean children and "Because tiredness may affect VA, the participants were instructed not to stay up late". 

As for why you get eye strain, I actually found that JUST the eye strain (Asthenopia) from looking at a screen is due to "Binocular/Refractive Vision Accomodation" Blehm, C. (2005). 

Ok so your eye has a lens in front of the actual ball part of the eyeball. The lens takes beams of light from a point in space and refocuses them at the retina. Clearly, this focal point in space has to change to focus on objects closer or further from you. This is done via cilliary muscles that line the lens. Counterintuitively, the muscles relax when you look at something far away and contract when you look at something close up (ok so it's counterintuitive when you actually look at an eyeball.). So Blehm, C. (2005) say that this 'accomodation' for long periods of time is what causes eye strain. It is in fact just looking at things up close.

So it could be the case for paper books as well! Well, there are other symptoms

Side note: The paper also says that this effect does not cause any statistical effect on vision impairment that naturally occurs in old age (visual acuity loss). There is a bit of nearsightedness but it only occurs immediately after using a screen for a long time, so they call it "Transient Myopia".

Similarly, other symptoms present that aren't eye strain.

I think the most important, or at least the least trivial one, seems to be blink rate. according to Acosta M. (1998) " during performance of a computer task, the basal blink rate of about 12 blinks min− found in normal young subjects decreased by about half." Which is bad because "Dry spots of the precorneal tear film begin to appear 15–30 s after a blink (Doane, 1980) while corneal temperature drops at a rate of 0±033°C/s when the eyes are open (Efron et al., 1989)."

And honestly I haven't been able to find out why at all. I can try a bit later but I think I need a break from the screen now. Going to go look at some trees. Far away trees.

References:

Jeong H. (2010) "A comparison of the influence of electronic books and paper books on reading comprehension, eye fatigue, and perception" Electronic Library, The, Vol. 30 Iss: 3, pp.390 - 408

Cushman, W.H. (1986), “Reading from microfiche, a VDT, and the printed page: subjective fatigue and performance”, Human Factors, Vol. 28 No. 1, pp. 63-73.

Dillon, A. (1994), "Designing Usable Electronic Text: Ergonomics Aspects of Human Information Usage", Taylor & Francis, London.

Macedo-Rouet, M., Rouet, J.-F., Epstein, I. and Fayard, P. (2003), “Effects of online reading on popular science comprehension”, Science Communication, Vol. 25 No. 2, pp. 99-128.

Kang, Y., Wang, M.J. and Lin, R. (2009), “Usability evaluation of e-books”,Displays, Vol. 30 No. 2, pp. 49-52.

Blehm, C., Visnu, S., Khattak, A., Mitra, S., Yee, R. (2005) "Computer Vision Syndrome: A Review". Survey of Ophthalmology 50(3).

Acosta M., GALLAR J., BELMONTE C., (1999) "The Influence of Eye Solutions on Blinking and Ocular Comfort at Rest and During Work at Video Display Terminals", Experimental Eye Research , Volume 68, Issue 6, Pages 663-669, ISSN 0014-4835, http://dx.doi.org/10.1006/exer.1998.0656.

Doane, M. G. (1980). "Interactions of eyelids and tears in corneal wetting and the dynamics of the normal human eyeblink". Am. J. Ophthalmol. 89, 507–16.

This is fluorine.

And this is fluorene.

Chemists are assholes.

For all you biochemists - this should help you out in your next assignment. Bases read from the inside circle to the outside (i.e. the middle is the 5' end). 

For all you non-biochemists, you've surely heard DNA referred to as the "building block of life" but have you ever considered how one tiny molecule contains enough information to make a person?

What DNA actually contains is a gigantic list, 3 billion entries long, of Adenines Thymine Cytosines and Guanines (molecules that are a part of DNA, referred to as A,T,C,G) in a combination specific to each person. This list tells your body to make specific proteins which can go off and perform virtually all bodily functions.

Proteins are built from amino acids that are attached and folded together, much like ikea furniture and, much like ikea furniture, often requires liberal use of the alanine key. In this metaphor, DNA is the weird pictorial instruction manual except actually helpful.

But how does a combination of 4 letters manage to make the millions of proteins needed? Effectively by being a giant list of amino acids with instructions where to start and stop for each protein. One letter can't encode one amino acid, because there could only be 4. If we take combinations of two letters, then we can only make 16 (for all you mathematicians - they're unordered pairs with repetition i.e. 4^2). If we take 3 that's 64 (4^3). That can cover the 20 amino acids, start and stop instructions easily. These combinations of 3 are called codons. So what happens to the other 42? That must be the question to the meaning of life the universe and everything! Well ... possibly... but actually codons double up. It's referred to as "codon degeneracy", but "degenerate" in sciencewords (titledrop) means "redundant" in conversational english. You can see it clearly on the picture because each amino acid has quite a few codons that can code it. Except tryptophan and methionine but nobody likes them anyway.