61

Plant Sciences, Zoology & Evolution / What is the effect of fusion of chromosome 2 in human nuclear cell?

« on: 17/11/2017 06:31:05 »

https://en.wikipedia.org/wiki/Chromosome_2_(human)

Chromosome 2 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 2 is the second-largest human chromosome, spanning more than 242 million base pairs[5] (the building material of DNA) and representing almost 8% of the total DNA in human cells.

Chromosome 2 contains the HOXD homeobox gene cluster.

All members of Hominidae except humans, Neanderthals, and Denisovans have 24 pairs of chromosomes.[7] Humans have only 23 pairs of chromosomes. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[8][9]

The evidence for this includes:
The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[10][11]
The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere in the q21.3–q22.1 region.[12]
The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the q13 band, far from either end of the chromosome.[13]

According to researcher J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2."

What will happen if chromosome 2 in human zygote splits at its vestigial telomere?
Or alternatively, what if 2 chromosomes in chimpanzee's zygote corresponding to human chromosome 2 somehow fuse?
Is there any research about this?

62

Science Experiments / What makes this sulfonic acid spill move like this?

« on: 12/10/2017 15:21:10 »

I found a spillage of sulfonic acid moving strangely. Does anyone know what caused it?
The spillage keeps moving like this for quite a long time, but eventually fading. When the movement stops, it becomes more viscous, but not completely dry yet.

63

New Theories / Universal Utopia? What's The Universal Terminal Goal?

« on: 09/09/2017 07:41:27 »

In this thread I'd like to discuss if there is a goal or desired condition which is applicable for any organisms who have adequate time to evolve or develop until they are basically independent from condition of their natural environments.

64

New Theories / How many times would a light ray be reflected inside a circular mirror?

« on: 21/08/2017 09:16:13 »

How many times would a light ray be reflected inside a circular mirror?

Let's say we have a circular mirror which is reflective in inner side. A laser beam is shone through a small hole on the mirror. How many times the laser beam would be reflected, if the incoming angle is 10 degrees?

65

Physics, Astronomy & Cosmology / How are muons detected and generated?

« on: 12/07/2017 06:36:20 »

Does anyone has reference to :
How to detect muons?
How to generate them in a lab?
How to distinguish between muon and other particles?

66

Physics, Astronomy & Cosmology / What is the effect on the moon's orbit of harvesting tidal energy?

« on: 19/05/2017 10:32:29 »

Harvesting energy from tides is known to make the Earth to rotate slower, but what is the effect on the moon's orbit? Measurements shows that the moon is moving away from Earth, but that means its potential energy is increasing?

67

Physics, Astronomy & Cosmology / Can an electromagnet erase a permanent magnet?

« on: 03/05/2017 12:30:25 »

Can we demagnetize a permanent magnet by applying electromagnetic field in reverse polarity?

68

Physics, Astronomy & Cosmology / Which clock is faster: clock in ISS or clock in geostationary satellite?

« on: 03/04/2017 10:46:22 »

Both clocks experience microgravity, in a state of freefall. But they move at different speed relative to the earth. They are also at different gravity potential.

Which clock ticks faster?

69

Physics, Astronomy & Cosmology / Do far away galaxies appear to rotate slower than they are?

« on: 28/03/2017 23:48:11 »

Red shift of far galaxies are interpreted as doppler effect which means that they are receding from us. This should make their movements look slower than they are, including molecular vibration.           
Are there any research on this?                                       

70

That CAN'T be true! / Do satellites need time synchronization among one another?

« on: 24/10/2016 02:53:57 »

According to theory of relativity, moving satellites are experiencing time dilation hence require time compensation when measured from "stationary" earth based station.
Following the premis, according to one satellite, another satellite located on the other side of the earth is moving twice as fast as it is measured from the earth, assume they have the same height and speed, and direction as going around the earth. Do they need periodic time adjustment to synchronize their time keeping?
What if the other satellite is moving in the opposite direction?

71

Physics, Astronomy & Cosmology / Can Newtonian Precession of Mercury's Perihelion Be Solved Numerically?

« on: 20/10/2016 14:54:01 »

While reading history of scientific progress I got interested to the discovery of planet  Neptune as confirmation for the validity of Newton's gravity. This led Urban LeVerrier to hypothesize the existence of planet Vulcan to explain precession of Mercury’s perihelion.
I'm curious at how LeVerrier got his results, and after some searching I found this article.

http://www.mathpages.com/home/kmath280/kmath280.htm

But then I realized that the methods described there involve some approximations, even though we are looking for very small discrepancy (43 arcseconds per century), perhaps due to computational limitation of that time.



Does anyone know about more accurate method to calculate Newtonian precession of Mercury’s perihelion?
What is the actual difference compared to observation?

72

Physics, Astronomy & Cosmology / Is the photon model of electromagnetic wave an oversimplification?

« on: 05/10/2016 11:12:16 »

In most theories up to the eighteenth century, light was pictured as being made up of particles. Since particle models cannot easily account for the refraction, polarization, diffraction and birefringence of light.

Photon model gains reputation in early 20th century due to photoelectric effect, especially that low frequency light cannot poduce emitted electron even with increased intensity. But newer development of laser can generate high enough intensity which can poduce emitted electron even with lower frequency than usual threshold.

Is photon model of electromagnetic wave an oversimplification?
Is it possible to explain wave-like phenomena in electromagnetism using photon model?
Is it possible to explain particle-like phenomena in electromagnetism using wave model?

73

New Theories / Origin of magnetic force

« on: 02/07/2016 11:54:21 »

Nowadays most people explain daily electromagnetic phenomena using Maxwell’s theory, which was a summary and development of the thoughts of 19th century scientists like Gauss, Faraday, and Ampere. When it was realized that Maxwell’s theory is not compatible with Newton’s mechanics, Einstein chose to modify Newton’s mechanics to comply with Maxwell’s equations, hence established the SR theory. As time goes by, thermodynamics led Max Planck to start quantum theory which was later developed to explain microscopic world. But on macroscopic scale, its result is similar to Maxwell’s theory.
I guess that the incompatibility can be resolved by modifying or even replacing Maxwell’s theory, instead of Newton’s mechanics. One thing that I concern the most is about the origin of magnetic force. Maxwell’s theory implies that magnetism comes from moving electric charge. Magnetic field was introduced to explain how magnetic force works. The field was based on magnetic lines of force which were introduced by Faraday.
Basically, Maxwell’s theory explains magnetic force in two steps. First, moving electric charges produce magnetic fields around their trajectory, according to right hand rule. Then the field will do a magnetic force to any electric charge which moves relative to it. Therefore, this theory seems to have difficulties when explaining point to point interaction, especially regarding asymmetry between action and reaction. This kind of interaction is the very thing that should be explained by any fundamental physics theories like Newton’s gravity and Coulomb’s static electricity, since point is the simplest geometric element, and any other geometric forms are built from it.

As an alternative, Edward Purcell tried to explain electromagnetic force relativistically, here
http://en.wikipedia.org/wiki/Relativistic_electromagnetism#The_origin_of_magnetic_forces.
There was shown that electric current in the wire is produced by the stream of positively charged particles, while common knowledge says that it is produced by the flow of electron which is negatively charged. If we see closer, it will be seen that positive and negative charges in the wire act asymmetrically.

74

Physics, Astronomy & Cosmology / What is the duration of a single photon?

« on: 17/06/2016 11:25:36 »

http://phys.org/news/2008-04-world-shortest-photon-pulse.html

The Oxford team can create individual photons that are 65 femtoseconds in duration: that’s approximately fifty times shorter than any single photon previously produced.

Doesn't that mean that previous single photon is actually 50 photons in a row?
If in the future someone comes up with even shorter photon pulse, it would make this newly created single photon merely a series of photons?

75

Physics, Astronomy & Cosmology / What determines the spectrum produced by hydrogen?

« on: 25/05/2016 11:12:58 »

What conditions (temperature/pressure) determine whether hydrogen gas will produce atomic or molecular spectrum ?
Does the transition happens gradually or is there a distinct limit?

76

Science Experiments / How do microwaves behave?

« on: 07/04/2016 12:39:32 »

Basically this series of experiment is a sequel of previous experiments regarding diffraction of light, which leaves some unanswered questions. I hope from the next experiments we can build a workable model to explain the behavior of electromagnetic waves in general, and their interaction with matters.

video #1 : Introduction

In this video series we are going to investigate another form of electromagnetic wave, which is commonly called microwave. By doing so, hopefully we can get better understanding on the nature of electromagnetic wave.

A huge advantage of using microwave compared to visible light is its wavelength which is in the order of a few centimeters, which makes it convenient to manipulate. Variables obscured by the small scale of optical experiments can be easily observed and manipulated.

77

Science Experiments / Investigation on diffraction of light

« on: 29/03/2016 07:32:37 »

In this topic I'd like to share my investigation on diffraction of light. In the first video I talk about definition and misconceptions that are often made.

I'd like to hear your opinion on this issue.