Energy (E) is a useful quantity. It has certain properties and connections with other such measures, like momentum p. E is paired with time t, much like momentum p and distance x are such a pair. This pairing is known from classical mechanics and it shows up in relativity: The merging of t and x into one entity, space-time, leads straight to such a melting also of E and p. In quantum physics, the uncertainty Δx ~ 1/Δp is important, and it translates into Δt ~ 1/ΔE. We do not think that momentum p is a substance!

See Nuclear Reactions for Beginners to get an introduction to the basic concepts

Medical evidence is based on what is considered the strongest possible foundation, the placebo-controlled trial but a new paper in the Annals of Internal Medicine calls into question this foundation upon which much of medicine rests, by showing that there is no standard behind the standard – that is, there is no standard for the placebo.

The thinking behind relying on placebo-controlled trials is that to be sure a treatment is effective, it needs to compare people whose only difference is whether or not they are taking the drug. Both groups must think they are on the drug to protect against effects of factors like expectation. Study participants are allocated "randomly" to the drug or a "placebo" – a pill that might be mistaken for the active drug but is inert.

Stem cell therapies hold promise as a cure for diseases but not without some risk, since faulty regulation of stem cells leads to a huge range of human diseases.   Even before birth, mistakes made by the stem cells are a major cause of congenital defects and cancer can also be caused by the body losing control of stem cell function.

Guiding stem cells along the correct pathways and reversing their mistakes is one target of cancer research and scientists from Tufts University say they have identified a novel and readily modifiable signal by which an organism can control the behavior of stem cell offspring. 

Sure, high energy physics costs billions these days (and watch out for birds - and lightning) but table-top experiments with tuned lasers and sensitive detectors can also continue to achieve the precision necessary for exploring the basic laws of physics at the heart of relativity and quantum mechanics.

To get a basic understanding of nuclear reactions, a high school level knowledge of a few basic concepts will suffice. In this regard, I'll start with a short recap of some concepts that will be used.

Structure of the atom

A basic atomic model will suffice for our discussion. In general, we can consider the atom to be composed of protons and neutrons tightly bound within the nucleus of the atom surrounded by electrons. The nucleus comprises almost the entirety of the mass of the atom, while the orbiting electrons make up the size of the atom.

Nuclear reactions