#SCIENCE!!!
A blog for lovers of all things science, made by two students who are fascinated by all the scientific wonders of the universe. Daryl is pursuing a career in higher education and cell and molecular biology and Khris is a future coroner getting close to her M.D. Also feel free to ask us anything!
Can you please explain the physics behind a bow and arrow? What happens when the arrow flys?
Anonymous

I’ll answer that question in a different post whenever I can get around to it. I’ll cover it in a good amount of detail :D

Reblogged from the-science-of-time  2,166 notes
thatscienceguy:

Where the different rules of physics apply:
Regular, otherwise known as Newtonian physics only applies on the average, everyday, scale. That is, objects larger than an atom at low energy, where energy in this context refers to velocity and (sometimes) temperature.
Once you step it up, increasing to high energy levels, (when velocity approaches c, the speed of light) newtonian physics no longer works due do what we call relativity, and observations or calculations need to take into account this effect usually using some form of the Lorentz factor,
gamma = [ 1 - (v^2)/(c^2) ]^(-1/2)
On the other hand, if you keep to a low energy system but bring the scale down to sub-atomic particles, such as electrons, things change yet again, but this time in an entirely new way. This is where Wave-Particle dualtity theory comes into play, the theory that waves (namely electromagnetic, i.e. light) are particles, and particles are wave packets. not only do you need to account for this, but you also need to take into account Heisenbergs uncertainty principle; It is impossible to know both the exact velocity and exact position of a sub atomic particle, the more certain you make one the less certain the other becomes.
Finally we come to Quantum Field Theory, which i honestly do not know anything about, at least i won’t until third year physics when i start taking courses on it.

thatscienceguy:

Where the different rules of physics apply:

Regular, otherwise known as Newtonian physics only applies on the average, everyday, scale. That is, objects larger than an atom at low energy, where energy in this context refers to velocity and (sometimes) temperature.

Once you step it up, increasing to high energy levels, (when velocity approaches c, the speed of light) newtonian physics no longer works due do what we call relativity, and observations or calculations need to take into account this effect usually using some form of the Lorentz factor,

gamma = [ 1 - (v^2)/(c^2) ]^(-1/2)

On the other hand, if you keep to a low energy system but bring the scale down to sub-atomic particles, such as electrons, things change yet again, but this time in an entirely new way. This is where Wave-Particle dualtity theory comes into play, the theory that waves (namely electromagnetic, i.e. light) are particles, and particles are wave packets. not only do you need to account for this, but you also need to take into account Heisenbergs uncertainty principle; It is impossible to know both the exact velocity and exact position of a sub atomic particle, the more certain you make one the less certain the other becomes.

Finally we come to Quantum Field Theory, which i honestly do not know anything about, at least i won’t until third year physics when i start taking courses on it.

Reblogged from compoundchem  1,255 notes
compoundchem:

mrdavisspeaksout:

allegoryblack:

compoundchem:

Ever wondered how much water/caffeine/alcohol you’d need to drink to reach a lethal dose? This graphic shows the median lethal dose for all three!Read more detail about LD50 tests in the accompanying post: http://wp.me/p4aPLT-ol

Don’t think this is accurate at all. Took 21 shots my my 21st birthday. Ten straight then 5 mins later 11 more.

I was debating the shots as well. I have taken more than 13 in one night

I feel it’s worth taking the time to clarify some points on the LD50 of these substances - the information is present in the graphic/accompanying article, but seems to be being overlooked.Firstly: the LD50 value is for a dose taken all at once. Secondly, it’s the value at which you’d have a 50% chance of death. Some people could drink more than this and live; conversely, some could drink less than this and die. The figures are also for a person of average weight (75kg), and in reality physical and medical conditions are also factors.For alcohol, this is the calculated value, for the alcohol content specified (40% alcohol, 45ml shots). Personal drinking history, whether or not you’re drinking on an empty stomach, and physical/medical condition can all affect this value.

compoundchem:

mrdavisspeaksout:

allegoryblack:

compoundchem:

Ever wondered how much water/caffeine/alcohol you’d need to drink to reach a lethal dose? This graphic shows the median lethal dose for all three!

Read more detail about LD50 tests in the accompanying post: http://wp.me/p4aPLT-ol

Don’t think this is accurate at all. Took 21 shots my my 21st birthday. Ten straight then 5 mins later 11 more.

I was debating the shots as well. I have taken more than 13 in one night

I feel it’s worth taking the time to clarify some points on the LD50 of these substances - the information is present in the graphic/accompanying article, but seems to be being overlooked.

Firstly: the LD50 value is for a dose taken all at once. Secondly, it’s the value at which you’d have a 50% chance of death. Some people could drink more than this and live; conversely, some could drink less than this and die. The figures are also for a person of average weight (75kg), and in reality physical and medical conditions are also factors.

For alcohol, this is the calculated value, for the alcohol content specified (40% alcohol, 45ml shots). Personal drinking history, whether or not you’re drinking on an empty stomach, and physical/medical condition can all affect this value.

Reblogged from scientific-women  1,027 notes

scienceyoucanlove:

Today on ‘just vaccinate your fucking children already’ news: 

Childhood vaccines are safe. Seriously.

By Jen Christensen and Nadia Kounang, CNN

(CNN) — Children should get vaccinated against preventable and potentially deadly diseases. Period.

That’s what a project that screened more than 20,000 scientific titles and 67 papers on vaccine safety concludes this week. The review appears in the latest edition of the medical journal Pediatrics.

The evidence strongly suggests that side effects from vaccines are incredibly rare, the study authors said. They found no ties between vaccines and the rising number of children with autism, as a small but vocal group of anti-vaccine activists, including actors Jenny McCarthy and Jim Carey, have said.

(Retracted autism study an ‘elaborate fraud’)

The review also found no link between vaccines and childhood leukemia, something that was suggested inearlier studies.

The researchers found that some vaccines did cause a few adverse effects but it was only for a tiny fraction of the population.

There was evidence that the meningococcal vaccine can lead to anaphylaxis — a severe, whole-body allergic reaction — in children allergic to ingredients in the vaccine. Other studies found the MMR vaccine was linked to seizures.

"Vaccines, like any other medication, aren’t 100% risk free," said Dr. Ari Brown an Austin, Texas-based pediatrician and author of the popular book “Baby 411,” who was not involved with the study.

"You have a sore arm, redness at the injection site. Those are the things we see commonly. Fortunately the serious adverse effects is extremely rare."

Brown said parents ask her how safe vaccines are all the time. Some patients also ask if they should delay or stagger the vaccinations. She counsels against that practice. She said the younger the child, the more danger these diseases present.

"By delaying the vaccines you’re putting your child at risk," Brown said.

(Study: Don’t delay measles vaccine)

The positive effects of vaccines dramatically outweigh the bad, experts said.

An editorial accompanying the study calls vaccines “one of the most successful public health achievements of the 20th century.”

Because of vaccines, many diseases that plagued children for centuries have all but been eliminated.

"There were good reasons that these diseases were targeted for vaccine development since they are so life-threatening," said Dr. Carrie Byington, vice-chair for research in the University of Utah’s pediatrics department, and the new chair for the American Academy of Pediatrics committee on infectious diseases.

Millions of Americans live longer on average because of the protection vaccines provide. Life expectancy has gone up in the United States by more than 30 years. Infant mortality decreased from 100 deaths per 1000 to 7 between the 1900s and 2000. 

read more from CNN (also links to study findings are in parentheses throughout the text)

also CNN link, goes to article and video, video starts on it’s own so be careful.

Reblogged from shychemist  269 notes
pennyfornasa:

While today may belong to the 45th anniversary of the Apollo 11 lunar landing, it’s important not to forget another important anniversary for NASA - the landing of the Viking 1 spacecraft on Mars!On July 20th, 1976, the Viking 1 lander separated from the orbiter and touched down at Chryse Planitia, a flat lowland region in the northern hemisphere of Mars. Immediately following touchdown, the lander made history by taking and transmitting the first complete photograph taken from the surface of Mars. The image (http://goo.gl/6C5L6m) was of the Viking 1 lander’s foot as an indication of how far it had sunk into the Martian surface. Between itself and its companion, Viking 2, this historic photograph was just the first of more than 50,000 images taken from the Martian surface, as well as from orbit, and transmitted back to Earth.What makes Viking 1 especially worth noting is that it was not only the first attempt by the United States at landing on Mars, but it was also the first spacecraft to successfully do so and perform its mission. While the Soviet Mars 3 mission was the first to achieve a soft landing of a spacecraft on Mars it stopped transmitting data 15 seconds after landing. During those few seconds of transmission, it sent the first partial photograph taken from the surface of Mars although nothing was identifiable in it.During its operation on the Martian surface, Viking 1 became the record holder for longest Mars surface mission at 2307 days, until Mars Rover Opportunity took the record in 2010.To read more about Viking 1:http://goo.gl/NOxjpMhttp://goo.gl/iKPlJ6http://goo.gl/6klaq9

pennyfornasa:

While today may belong to the 45th anniversary of the Apollo 11 lunar landing, it’s important not to forget another important anniversary for NASA - the landing of the Viking 1 spacecraft on Mars!

On July 20th, 1976, the Viking 1 lander separated from the orbiter and touched down at Chryse Planitia, a flat lowland region in the northern hemisphere of Mars. Immediately following touchdown, the lander made history by taking and transmitting the first complete photograph taken from the surface of Mars. The image (http://goo.gl/6C5L6m) was of the Viking 1 lander’s foot as an indication of how far it had sunk into the Martian surface. Between itself and its companion, Viking 2, this historic photograph was just the first of more than 50,000 images taken from the Martian surface, as well as from orbit, and transmitted back to Earth.

What makes Viking 1 especially worth noting is that it was not only the first attempt by the United States at landing on Mars, but it was also the first spacecraft to successfully do so and perform its mission. While the Soviet Mars 3 mission was the first to achieve a soft landing of a spacecraft on Mars it stopped transmitting data 15 seconds after landing. During those few seconds of transmission, it sent the first partial photograph taken from the surface of Mars although nothing was identifiable in it.

During its operation on the Martian surface, Viking 1 became the record holder for longest Mars surface mission at 2307 days, until Mars Rover Opportunity took the record in 2010.

To read more about Viking 1:
http://goo.gl/NOxjpM
http://goo.gl/iKPlJ6
http://goo.gl/6klaq9

Reblogged from shychemist  1,038 notes

I meet many people offended by evolution, who passionately prefer to be the personal handicraft of God than to arise by blind physical and chemical forces over aeons from slime…What they wish to be true, they believe is true.

Only 9 percent of Americans accept the central finding of modern biology that human beings (and all other species) have slowly evolved by natural processes from a succession of more ancient beings with no divine intervention needed along the way.

By Carl Sagan (via whats-out-there)

completed-nihilism:

Vantablack

British researchers have created the ‘new black’ of the science world - and it is being dubbed super black.

The material absorbs all but 0.035 per cent of light, a new world record, and is so dark the human eye struggles to discern its shape and dimension, giving the appearance of a black hole.

Named Vantablack, or super black, it also conducts heat seven and half times more effectively than copper, and is ten times stronger than steel.

It is created by Surrey NanoSystems using carbon nanotubes, which are 10,000 thinner than human hair and so miniscule that light cannot get in but can pass into the gaps in between.

Article