subject: science


Fossil Fish Skull (Xiphanctinus audax, Cretaceous) -  Niobrara Formation, Kansas

This sinister looking skull once belonged to a predatory fish that dominated the Western Interior Seaway known as Xiphactinus which was much longer than any bony fish of today. The beast is represented here by just a skull and some post-cranial material, but the point gets across nonetheless.

R Aquarii is known as a symbiotic star made up of a white dwarf–red giant binary pairing. These two stars are tied in orbit around one another with a period of around 44 years. The primary star is a variable red giant, meaning it changes temperature and undergoes drastic brightness fluctuations. The secondary star is a white dwarf that sucks in material from the red giant. Some of the extra material is sometimes ejected, forming the incredibly stunning nebula surrounding it.

(Credit: Hubble Space Telescope/Judy Schmidt)

anonymous asked:

what kind of stomach problems are common in autism? is it diagnosable disorders or more general issues like frequent indigestion?

There are a wide variety of gastrointestinal problems that are more common in autistic people than in the general public. These can include celiac’s, food allergies/intolerances, IBS/IBD, acid reflux, and others. However, there is a lack of (non-biased, actually scientific, good) research into this subject, and many autistic people who have GI problems don’t get the appropriate diagnosis for those issues because of bias in the medical field. There are far too many doctors who think that GI problems are just a part of autism and thus don’t do any further investigation into what might be causing these problems. 

To be clear, GI problems are NOT part of autism. There are just medical conditions that are more likely to occur in autistic people. 


anonymous asked:

Hi, where do you stand on scientific realism vs. anti-realism?

That’s a tough one. For starters, it’s hard to position ourselves in this debate. As the SEP article puts it, ‘It is perhaps only a slight exaggeration to say that scientific realism is characterized differently by every author who discusses it, and this presents a challenge to anyone hoping to learn what it is.’

But, for some quick and dirty and jaw-droppingly incomplete background, scientific realism is, roughly, an epistemic attitude that our best scientific theories and models track something real. In other words, scientific realism is the idea that science tells us about the true nature of reality. Anti-realism, on the other hand, includes broad schools of thought that reject this idea. Included in the camp of anti-realism, for instance, is instrumentalism, which says that science helps us predict how the world will play out, but it doesn’t necessarily tell us anything about the ‘true nature’ of reality.

Personally, I fall somewhere in between these two camps. I’m a fan of schools of pragmatic realism—which is to say we are inherently constrained by the type of species we are, but this does not make our reality somehow inauthentic or ‘less real’ than some other dimension of reality. What humans experience is real and science can help us understand it, but it’s certainly not the entire picture. We are not epistemically quarantined from reality, nor do we have privileged or adamantine access to it.


Pollution Kills More People Than War, AIDS, Malaria Combined

- The Young Turks


More info here.

a-beepbop  asked:

What dictates the lower size limit for mammals?

Well firstly, how small can mammals get? Well the smallest mammals are: 

  • Etruscan shrew (Suncus etruscus):  3 – 5.2 cm
  • Pygmy possum (Cercartetus nanus): 5 - 10cm
  • Kitti’s hog-nosed or the bumblebee bat (Craseonycteris thonglongyai): 2.9-3.3cm 

Generally mammals can’t get much smaller then <2cm. It’s all to do with ratios and surface area to volume (this involves alot of math that I can’t easily explain in detail on tumblr and to be honest math was never my strong suit!)

To summarise it, the SA:V ratio is: 

smaller animals have more SA compared to their volume therefore they lose energy / heat faster compared to a larger animal that has a big volume compared to the smaller SA. Therefore larger animals are better at thermoregulating and lose energy / heat slower compared to a smaller animal.

This is why smaller vertebrates have to eat a lot of food compared to their volume and why they often have faster heart beats.

This is why invertebrates can be so small compared to vertebrates. Inverts often have simplistic and more “primitive” in some ways morphology and physiology. They often don’t need to maintain heat or energy compared to larger more complex vertebrates.

Here are some websites that go over the concept in much more detail.

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