Science Nerd

Example: every single time I smell a bar of dove soap, I think of this one kid I used to go to school with. Now, I can't tell you his age. I can't tell you his favorite color. I can hardly tell you his first name.

But I remember that he always smelled like dove soap.

No matter what. It's like he carried dove soap around in his pockets. Just plain old dove white soap. And it was so strong but not overpowering— like, it wasn't a dove deodorant or something, it was like straight-up smelling a bar of dove soap whenever you were near him.

So now every time I smell dove soap he pops into my mind.

Why?

I can hardly remember my tumblr password sometimes, I forgot my own age a bit ago and had to use a calculator to figure it out. But no matter what, I remember this kid from fifth grade always smelled like dove soap.

When you use any of your senses besides smell the information is routed to a portion of your brain called the thalamus. This is more or less a relay station in your brain where the information is sorted and sent to the correct portions of your brain like the hippocampus which controls memory or the amygdala which controls your emotions.

However, with smells it is different. When you smell something the information goes straight to a place in your brain called the olfactory bulb, which is your smell center. This part of your brain is actually directly connected to the hippocampus and the amygdala which is why it seems we have a stronger connection between smell and memories.

Now, another question pops up which is why is it this way? Why do we have a specific area in our brains for just smell, and not the other senses. The short answer is we aren’t quite sure, however it seems that most people have come to a general consensus, that it has to do with how we evolved. Smell is one of the most rudimentary senses that we have had, linking itself to even how single cell organisms reacted with chemicals and other organisms around them. It may also be attributed to the fact we have over 1,000 smell receptors, and only 4 different types of light sensors and only 4 types of touch receptors.

Human memory is such a curious and infinitely complicated thing. We are learning more and more every day, yet have such a long way to go discovering how our own brain works even.

So the short answer to your first question is yes, but in the exact opposite way you think. In fact, unless there are special circumstances you will find that it is the larger of the planets that indeed rotate faster than the smaller ones.

Here is a chart of rotation speeds of our own solar system.

The initial thinking of smaller objects being able to rotate quicker because the mass is closer to the central axis is called angular momentum, for example just like a figure skater pulling their arms and legs in close to be able to spin faster. So why isn’t it like this when it comes to the planets?

The simple answer is this. Larger planets were made from larger clouds of stuff, so once the planets started to contract and form, they had more mass and therefore more momentum during their formation which equates to a faster rotation.

This is, of course, a general idea, as space is chaotic. Collisions happen and can either make a planet rotate faster, slower, or even backwards (retrograde), but as a general rule, most planet formations and rotations will follow the same patterns.

(Source.)

-Admin Mike

We can get relatively close to a complete vacuum however it is completely impossible to have a perfect or complete vacuum. A complete vacuum is defined as an area with absolutely zero particles inside said region of space. So why is this the case? There are two main reasons why we can never reach this.

The first reason is that whatever container you are attempting to make a perfect vacuum must be kept at a constant temperature of zero degrees Kelvin (0°K), also known as absolute zero. If it is not kept at this temperature it will radiate photons from the container, which can, in turn, create electron and positron pairs that can appear inside of the container. Is it possible to reach absolute zero though? The answer is, unfortunately, no, however, we can get really close, about a billionth of a degree Kelvin. Want to know why? Click here to learn more about why we can’t reach absolute zero.

The other main reason why we will never be able to create an absolute perfect vacuum is because of weakly interacting particles, such as the neutrino. No matter how thick the container is there will always be a finite possibility that a neutrino or other particle will and could enter the region. To learn more about neutrinos and other weakly interacting massive particles (WIMP’s) click here.

To the second question, CERN did, in fact, create antimatter all the way back in 1996. They created antimatter that lasted for about 40 billionths of a second before it was annihilated by ordinary matter. To read more about CERN and antimatter click here.

-Admin Mike

Also, question by anonymous:

If the universe is infinite, aren’t we all the center of the universe?

There are two main questions here:

Is our universe a flat, open, or closed universe?

Is our universe infinite or finite?

Let’s start off by answering the first question. To answer this question we need to figure out the answer to another question, is the density of the universe less than, equal to, or more than the critical density of the universe?

So what does this mean? Our universe is in a constant battle between the expansion of our universe and gravity trying to pull itself back together. The rate of expansion is expressed through the Hubble Constant shown as Ho (For more information on the Hubble Constant and how we figured it out, click here) and the strength of gravity is due to the overall density of the universe. The critical density is equal to the square of the Hubble Constant, and that’s where the two compensate each other. 

Open Universe (Negative curvature) - If the overall density is LESS than the critical density, then we will have an open and infinite universe shaped like a saddle (or the equivalent of a saddle in the dimensions or universe has). The expansion of the universe will go on forever in this shape and never cross back into itself. 

Closed Universe (Positive curvature) - If the overall density is MORE than the critical density, then we will have a closed universe. This type of universe would be technically a finite volume yet have no boundaries or edges. You could travel in any direction forever and never reach an “edge” of the universe.

Flat Universe (No Curvature) - If the overall density is equal to the critical density, then we will have a flat universe that is either infinite or finite. While our we can definitively calculate our observable universe in this case, we would not be able to tell if it is indeed finite or infinite.

So now that we have been over what these different shapes our universe can be, what shape is it actually? Well for a long time we had no idea, but recently mainly due to a spacecraft called WMAP, we have discovered that the universe is indeed flat (within a .4% margin). You may be asking yourself, how is our universe flat? We will live in a 3D world and can move in all directions in space. Well if you are interested in how this may be please watch this short video from NASA explaining how this can be, and also how they came to the conclusion that the universe is indeed flat yet ever expanding.

So, finally we can begin to start trying to answer the second question. Is our universe infinite or finite? If it is finite, could we find a center? Well since we know with relatively good margins that our universe is flat, this makes answering this question a little harder. The short answer to this is, we don’t know for sure. We have to first make the distinction between our observable universe and the actual universe. We can calculate (and actually have) the size of our observable universe and it is about 93 billion light years across. What lays outside of our observable universe? We don’t know, however what we do know is that it is always expanding, so technically it will be an infinite amount of volume in an infinite amount of time even if it is of a finite space right now.

So, can we find the center of the universe? Depends on which universe you are talking about. If you are talking about the observable universe, then we are ALWAYS the center of the universe, because it is always relative to your position. If we are talking about the full universe, the answer is probably not. We cannot observe anything outside of our scope of light that has reached us, and even then the universe could be infinite, which indeed has no center.

If you are still interested in this topic please check out this video!

Links/Sources

How do we know the universe is flat? Discovering the topology of the universe, Phys.Org

What is the Shape of the Universe?, Space.com

- Admin Mike

In short, a super massive black hole is what awaits us at the center of our universe. We have named it Sagittarius A or Sgr A* for short. It is about 26,000 light years away or 150,000 trillion miles away. Surrounding this black hole is about 25 to 30 massive stars called Wolf-Rayet stars (For more information on Wolf-Rayet stars click here). These stars are being constantly pulled by Sgr A* and therefore eject part of their gases which collide with space dust and other gases, causing huge, super hot shock waves. Since these waves are so hot, they actually produce x-rays and we are able to see these reactions with the Chandra X-Ray Telescope.

So, how do we know there is a black hole in the center of our galaxy? Well, black holes are so dense, they cause reactions with stars and space dust around them, just like the Wolf-Rayet stars. These reactions cause an abundance of x-rays and radio waves, and with newer technology we are now about to detect these from so far away. Not only that, but we have visually seen the paths of stars orbiting something in such a way, that even though we cannot see it, it must be something as dense as a black hole.

To read more about how we found out about about the black hole in the center of our galaxy, click here.

For a 360 degree visual from NASA of the center click here.

- Admin Mike

To answer this question, we must first define exactly what heat is. Heat is the transfer of energy from the difference in temperature from one system and its surroundings. Temperature is the average amount of kinetic energy inside of said system. We have to realize that heat is energy in transit. When molecules are heated, what you are doing is just transferring energy to these molecules which makes them vibrate and move around more. It is during this heating process that can break the bonds between the molecules, which causes state changes (solid to liquid or liquid to gas).

Watch this video for a visual explanation.

-Admin Mike

Check out his personal blog here.

How was the universe created? This question itself gave birth to a whole form of science called cosmology. This is a surprisingly new form of a science that was created to answer just this question. In this short period of time we have discovered what happened up to the very beginning point in time. The Big Bang Theory is the most widely accepted theory of how our universe began. While this theory is the most accepted, we can trace everything back to the beginning point of our universe, we don’t yet know what happened before, so this is where we will start.

In the beginning (about 13.8 billion years ago), every single particle of energy and matter of our universe was compacted into an almost unimaginable dense and hot point. We call this a gravitational singularity or simply singularity. What caused this singularity to form, or what happened before, or even if there was anything before, is still at great debate. While we don’t know why, we do have a pretty good idea what happened next. There was a rapid inflation period within the first moments of our universe being born (about a billionth of a trillionth of a trillionth of a second). After this period our universe is about the size of a golf ball, it is filled with the building blocks of matter called plasma.

Since our universe is expanding exponentially it is also going through a massive cooling period as well. Within three minutes nuclear fusion begins, creating our first protons and neutrons. After 20 minutes, because of cooling, nuclear fusion ceases, leaving us with about 99% of all matter that we have today, consisting of 75% hydrogen, 25% helium, and a very small amount of lithium and beryllium as well. From here on out, things began to slow down. Light didn’t first appear until about 370,000 years later, stars formed about 200 million years later, and galaxies formed about 400 millions years after that.

If you want learn more please check out this Wikipedia article that breaks down the beginnings of our universe.

- Admin Mike

So the universe was supposed to have began/the big bang was supposed to have happened 13.7 billion years ago....

Yet, we on earth measure years based on the rotation of our planet around the sun.......

So how can we measure the years it has been since the beginning of the universe if our planet and our Sun didn't even exist then?

Dear science side of tumblr,

hey random question for the science side of tumblr…

hey random question for the science side of tumblr…