The Naked Scientists
  • Login
  • Register
  • Podcasts
      • The Naked Scientists
      • eLife
      • Naked Genetics
      • Naked Astronomy
      • In short
      • Naked Neuroscience
      • Ask! The Naked Scientists
      • Question of the Week
      • Archive
      • Video
      • SUBSCRIBE to our Podcasts
  • Articles
      • Science News
      • Features
      • Interviews
      • Answers to Science Questions
  • Get Naked
      • Donate
      • Do an Experiment
      • Science Forum
      • Ask a Question
  • About
      • Meet the team
      • Our Sponsors
      • Site Map
      • Contact us

User menu

  • Login
  • Register
  • Home
  • Help
  • Search
  • Tags
  • Member Map
  • Recent Topics
  • Login
  • Register
  1. Naked Science Forum
  2. Profile of Nicholas Lee
  3. Show Posts
  4. Posts Thanked By User
  • Profile Info
    • Summary
    • Show Stats
    • Show Posts
      • Messages
      • Topics
      • Attachments
      • Thanked Posts
      • Posts Thanked By User
    • Show User Topics
      • User Created
      • User Participated In

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

  • Messages
  • Topics
  • Attachments
  • Thanked Posts
  • Posts Thanked By User

Messages - Nicholas Lee

Pages: [1] 2 3 ... 5
1
General Science / Re: Have I built the world's first human memory erasing machine?
« on: 29/08/2016 04:46:36 »
Once you have located the target volume you wish to destroy how do you keep the brain still while you blast it ?
The assumption seems to have been made that the storage of one memory is stored in just one location this seems very unlikely to me to take the similar case of a computer if you accidentally load a rogue program  it can be very difficult to remove it completely as little bits and pieces of it are stored all over the place often with numerous copies I have an uninstalling program that hunts for remnants and often finds hundreds !
The following users thanked this post: Nicholas Lee

2
General Science / Re: Have I built the worlds first human memory erasing machine.
« on: 28/08/2016 21:22:07 »
"Have I built the worlds first human memory erasing machine?"
No.
For a start you have not built anything for a finish, as far as I can tell you have not learned about scattering of gamma rays. Collimating beams isn't as easy as you seem to think.
For an encore you don't seem to have taken account of the damage done by the beam before it reaches the target.
I think you are suggesting that if you use many beams than only the part of the brain at the point where all the beams line up will get the maximum dose.
That's true but each time you add another beam you add more damaged tissue because the beam has to go through the brain to get to the intersection point.
The following users thanked this post: Nicholas Lee

3
Technology / Re: Could you erase human memories specifically in mice with this technique.
« on: 11/08/2016 07:58:21 »
I doubt that the average mouse has any human memories.

The human hippocampus is interesting. It turns out that London taxi drivers actually develop an outsize hippocampus. This phenomenon has been known for at least 30 years, but nobody knows why it is associated with supporting Tottenham Hotspur. 
The following users thanked this post: Nicholas Lee

4
Physics, Astronomy & Cosmology / Re: How small can a gamma wave, or gamma knife beam be collimated.?
« on: 09/08/2016 05:26:48 »
To focus on an area of 20 microns width, a good wavelength would be 2 microns or shorter. That would put it in the infrared band. Potentially therefore you can use any radiation shorter than that, including visible, ultraviolet, X, and gamma. If you want to ionize stuff using reasonable power levels, the quantum energy has to be sufficient, and ultraviolet may be sufficient.  It is probably possible to do what you want using presently-available lasers. The choice of wavelength would also be dictated by possible effects on the surrounding environment.  Lenses to handle radiations that are in the longer ultraviolet band and longer are no problem.  However,the nature of the source must also be taken into account. Not even the best lens can focus the light of an overcast sky into an intense pinpoint. Laser light is extremely focusable. But lasers tend to be available mainly in the visible and longer wavelengths. I don't know if ultraviolet lasers are available, but ultraviolet LEDs are readily available, but whether the power would be adequate is another question.  For X-rays, as far as I know we are still limited to vacuum tubes, but these certainly exist and are capable of producing a small emission source compact enough for imaging, which may well be workable with additional optics to give you the tiny impact zone you require.   With shorter wavelengths, things get more difficult, although X-rays have been successfully focused using grazing-incidence mirrors. I don't know any way to do pinpoint application of gamma rays except by direct insertion of a tiny radioactive source at the point of application.  I  think you should look first at visible lasers for brain surgery. However, if the point of application is inaccessibly within tissue, then X-rays may have to be considered. Here, the geometries could get complicated because the farther the point of application is from the lens or mirror structure, the harder it will be to get a narrow spot. This could be a problem if the source is an X-ray tube and the optics consist of grazing-incidence mirrors. (But of course, under such conditions, would you even be able to tell, to within an accuracy of 20 microns, exactly where to position it?) 
The following users thanked this post: Nicholas Lee

5
Technology / Re: Could FMRI, PET, CT, EEG, and MEG be more advanced, but it would take more Cost.
« on: 07/08/2016 09:30:22 »
This thread seems to assume that progress is not being made.
Is there any reason to suppose that is the case?
The following users thanked this post: Nicholas Lee

6
Technology / Re: Could FMRI, PET, CT, EEG, and MEG be more advanced, but it would take more Cost.
« on: 07/08/2016 08:20:15 »
More compute power and more memory never go astray when you are doing complex calculations on huge gobs of data.

The other major advance is in the area of DNA sequencing, which seems to be doubling in performance about every 9 months (last I heard). Again, lots of compute power, access to huge databases and efficient algorithms are just as important as improvements in the hardware which actually reads the DNA sequence.

In both cases, the main shortcoming is in automated understanding of what is being seen, so that the computer can identify patterns that jump out to the experienced eye.
The following users thanked this post: Nicholas Lee

7
Technology / Re: Could FMRI, PET, CT, EEG, and MEG be more advanced, but it would take more Cost.
« on: 06/08/2016 15:56:31 »
CT, MRI and DSA seem to be adequate for locating and to some extent characterising anatomical pathology, including some very subtle recent discoveries in the flow of cerebrospinal fluid. Incremental developments make these techniques easier to use but I don't see a need for or possibility of a quantum step in performance. To increase signal/noise ratio or spatial resolution you need to increase radiation dose or primary magnetic field, which introduces other problems (death or chemical shift artefacts, respectively). And there's not much point in resolving below the level at which we can reliably treat.

Functional imaging is limited not only by hardware but also by our limited understanding of what we are looking at. To a large extent FMRI and PET are mapping blood flow to active parts of the brain, and it's a bit like trying to find a lighted match in a well-lit room by mapping the oxygen flow towards it, or even the aircon that tries to counter the heat input. MEG does provide some fairly high resoluton images of electrical activity, but the simile here would be looking for a faint radio beacon in a thunderstorm - except that you still don't know whether what you have found is an airport, a seaport, or a police car!  EEG will identify gross malfunctions like stroke, epilepsy or death, but I can't see its inherent spatial resolution getting much better: God or evolution seems to have put an insulating  skull and a conductive scalp in the way of the electric field.  As of now, I think we can unequivocally detect and roughly locate the response to a given stimulus, but whilst functional imaging greatly helps clinical characterisation of disease, it's not a stand-alone diagnostic like CT, or ever likely to be.

Happy to be proved wrong!
The following users thanked this post: Nicholas Lee

8
Physics, Astronomy & Cosmology / Re: If you put electricity, magnetism, super heat, super cold in a mass the size of
« on: 05/08/2016 15:10:58 »
The temperature of a newly formed neutron star is much higher than that
https://en.wikipedia.org/wiki/Neutron_star
The following users thanked this post: Nicholas Lee

9
Chemistry / Re: Can any visible lights electron voltage be changed to increase, or decrease.
« on: 01/08/2016 10:53:14 »
Different semiconductors have a different bandgap, which require a different voltage to allow current to flow, and this produces light of different wavelengths.
https://en.wikipedia.org/wiki/Light-emitting_diode#Working_principle

Just as light production depends on the chemical structure, so light absorption depends on the chemical structure.

Unfortunately, if you are studying chemical structures, and you don't like the fact that they absorb light, the only option is to change the chemical structure, ie it is no longer the thing you were trying to study. [:(]
The following users thanked this post: Nicholas Lee

10
Chemistry / Re: Will removing a neutron from nucleus change electron voltage requirement.?
« on: 26/07/2016 12:16:38 »
Knocking out a neutron does not change the number of electrons or its electron energy levels significantly.

However, removing a neutron may make the nucleus unstable, so it may spontaneously change into a different element at some later time, for example by emitting a beta particle and a neutrino. This will change the electron structure.

For all but the lightest atoms, you need slightly more neutrons than protons for the nucleus to be stable.

You can see the stable combinations of protons and neutrons here:
https://en.wikipedia.org/wiki/Neutron%E2%80%93proton_ratio#/media/File:Isotopes_and_half-life.svg
The following users thanked this post: Nicholas Lee

11
Chemistry / Re: Will removing a neutron from nucleus change electron voltage requirement.?
« on: 26/07/2016 08:19:48 »
Neutrons have no net electric charge, so that to a first approximation, inserting them or removing them from a nucleus has no effect on the attraction of the nucleus to the surrounding electrons, and therefore would result in no change in the spectral characteristics of radiation absorbed by or emitted by the electrons as they jump between orbits. Actually, however, there could be a slight effect because the removal of a neutron would change the nuclear mass, which enters into the state equations governing how electrons orbit it.  This change would be very slight.  Also, the neutron has a magnetic dipole moment and appears to have a possible electrostatic dipole moment also, both of which would exert slight effects on the behavior of electrons. 
The following users thanked this post: Nicholas Lee

12
Chemistry / Re: Can knocking a proton from the nucleus make electrons, electron voltage change?
« on: 25/07/2016 10:37:45 »
Perhaps a related, but more effective technique is to identify a molecule which sticks to the biological protein you wish to study (eg Tau tangles). You ensure that some of the atoms in this "Tracer Molecule" emit some low-level radiation.

You then give the patient an injection containing the tracer molecule, and wait an hour (or a day) for the tracer to stick to the target molecule. You put the patient in a radiation detector, and this provides a map of where the tracer occurs in the body. This indicates the presence and distribution of the target molecule (eg Tau tangles).

This has the advantage that:
- The accelerator beam does not need to dislodge a lot of atoms between the person's skin to where the  Tau tangles might (or might not) exist. The tracer goes direct to the Tau tangles.
- If there are no Tau tangles, the tracer is excreted from the patient's body.
- There is less radioactive debris inside the patient

The following users thanked this post: Nicholas Lee

13
Chemistry / Re: Can knocking a proton from the nucleus make electrons, electron voltage change?
« on: 25/07/2016 10:29:43 »
Quote from: Timemachine2
If you knock a proton, or neutron out of the nucleus, I am not sure if the element changes to the next element up, or down in the periodic table, because it is now missing a proton, or neutron.
You could take a stable atom like Oxygen 17O = 8 electrons + 8 protons + 9 neutrons.
If you knock out 1 neutron, this leaves behind the stable atom Oxygen 16O = 8 electrons + 8 protons + 8 neutrons.
See: https://en.wikipedia.org/wiki/Isotopes_of_oxygen#Stable_isotopes

The electron energy levels of the two isotopes of Oxygen are pretty much the same.
There will be a bit of a difference in the infra-red spectrum, since vibrations of the molecule is affected the the mass of the Oxygen atom, not just the electron structure.

If you take 17O, and knock out one proton, you will be left with the unstable atom of Nitrogen 16N = 7 electrons + 7 protons + 9 neutrons.
Nitrogen has quite a different electron energy levels and spectrum than Oxygen.

However, because this Nitrogen isotope is unstable, it breaks down in about 7 seconds to Oxygen or Carbon.
See: https://en.wikipedia.org/wiki/Isotopes_of_nitrogen#Isotopic_signatures

Unfortunately, the results of atomic colisions are a bit more random than this - sometimes you will knock loose an alpha particle (2 protons+2 neutrons) or a Beta particle, and often there will be gamma rays produced. So you end up with quite a mix of atoms in the result.

There are some problems with this approach to medical imaging:
- It takes enormous energy from a particle accelerator to dislodge protons and neutrons from the nucleus of an atom
- This is much more dangerous than taking an X-Ray or CAT scan of a patient
- The impact of the collision imparts a lot of energy to the nucleus, ripping it right out of the atom.
- The electrons do not make a smooth transition from the energy levels of Oxygen to Nitrogen. The energy of the collision scatters the electrons everywhere.
- The energy of the incoming particle beam and the debris from the collision is far greater than the binding energy of biological molecules: perhaps millions of electron-volts, not just 1-4 eV. This tears apart the biological molecules you are trying to study.

So while nuclear transmutation does change the electron energy levels, it will destroy the biological molecules you are trying to study; if it doesn't kill the live patient immediately, it will give them radiation burns (or at least, cause so many mutations that it will give them cancer, eventually).

Nice try, Timemachine2!
The following users thanked this post: Nicholas Lee

14
Chemistry / Re: Why Is there a minus in electron volt requirement of electrons?
« on: 21/07/2016 20:50:28 »
It's a sign convention that you may find useful later. The energy level of a completely free electron is 0, and becomes negative as it approaches the nucleus. The value of the convention is that to promote an electron from an inner shell to an outer one, you have to add positive energy  (-13.6) + (+10)  = (-3.6), so you need at least  10 eV of photon interaction to make the transition. Equally, in returning to the unexcited state, the electron will emit a photon of 10 eV and the atom will lose 10 eV of energy, so the electron energy level will become "more negative". This makes sense as photons cannot have negative energy!
The following users thanked this post: Nicholas Lee

15
Chemistry / Re: If the hydrogen atoms electron COULD be kept in shell 2 without going back down
« on: 16/07/2016 06:10:06 »
I think the idea is unworkable for several reasons. One is that the human body has elements other than hydrogen to consider.  The human body could not be made transparent without dealing with iron, and in iron, simply making the lowest energy state unavailable would not do much good in the visible wavelengths because in iron that energy state is separated by others with much more energy than that of a visible photon, as are several other states.  Electrons in these states will affect the absorbtion or emission of ultraviolet or X-rays.  Another is that to achieve the necessary electron rearrangement would probably end biochemistry as we know it, killing the patient.  (Pushing electrons out of the lowest orbit and keeping them out would, if the atom is to remain neutral, cause the atom in the case of hydrogen to effectively become the next element up the periodic table, or for all other elements the second-next element up the periodic table.  That would change the whole shape of the chemistry radically). If, however, one wishes to study the spectral effects of making the lowest orbit unavailable, a good place to start is to study lithium, in which two electrons pair in the lowest energy state, leaving the third to do its business in other states only. 
The following users thanked this post: Nicholas Lee

16
General Science / Re: DNA switches can change electron energy levels , but physicist's cannot change
« on: 15/07/2016 11:57:51 »
Quote from: Timemachine2
DNA switches have the ability to change electron energy levels.

I guess:
  • If we lived entirely in the water, we would not need an opaque, calcium-rich skeleton.
  • ...and if we disposed of this energy-intensive brain, and got rid of the muscles that have made us the top predator in land habitats, we would not need an opaque, iron-rich bloodstream.
  • If we lived well below the surface, we would not need the opaque melanin layer to absorb UV light.
  • Humans are already fairly hairless (for a mammal), but with a lower metabolism we could dispose of all the hair
  • If we were cold-blooded, we would not need such large stores of insulating fat, and large organs to digest lots of food.
  • But all our enzymes would need to be modified so they worked well at ocean temperatures (eg 10-20C) instead of 37C.
That sounds to me like a lot of DNA switches & genetic modifications to make us transparent.
And the product in the end would hardly be human - in fact, it might look very much like a jellyfish.
The following users thanked this post: Nicholas Lee

17
Technology / Re: Do we have the tech to erase a human memory, with the INUMAC MRI machine, and
« on: 12/07/2016 15:18:01 »
I think you'd have better results using chemical means to prevent memory reconsolidation.
The following users thanked this post: Nicholas Lee

18
Technology / Re: Do we have the tech to erase a human memory, with the INUMAC MRI machine, and
« on: 11/07/2016 22:58:25 »
The gamma knife is a bit blunt for zapping individual neurons. You might do better with a cyberknife, but even then, we don't know how memory is distributed. Given the known process of slow recall with gradually increasing detail, it is more likely to be retained in k-space rather than real space so you might end up with a hugely detailed picture but no idea what it signifies or why it matters.
The following users thanked this post: Nicholas Lee

19
Chemistry / Re: Can DNA evolution switches in transparent animals change electron energy levels.
« on: 09/07/2016 12:37:49 »
Water is transparent with transparent animals having more water in many of their tissues. If you dry a jelly fish it will lose transparency.

Jello powder is made from the hide and bones of animals, both of which are opaque. It contains amino acids that can be used to fix water until you get a semi-solid that is transparent.

The following users thanked this post: Nicholas Lee

20
Chemistry / Re: Is electrons absorbing certain wavelengths of EM radiation, and electron energy
« on: 08/07/2016 13:03:35 »
This is very well explained by science. I have pointed you in the direction of molecular orbital theory before. I suggest you take some time to read up on what is known about it. You obviously have the time and desire to learn about this topic.

Here are some links to get you started, depending on your learning style:

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/mo.html
http://www.ch.ic.ac.uk/vchemlib/course/mo_theory/
https://en.wikipedia.org/wiki/Molecular_orbital_theory
The following users thanked this post: Nicholas Lee

Pages: [1] 2 3 ... 5
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.085 seconds with 62 queries.

  • Podcasts
  • Articles
  • Get Naked
  • About
  • Contact us
  • Advertise
  • Privacy Policy
  • Subscribe to newsletter
  • We love feedback

Follow us

cambridge_logo_footer.png

©The Naked Scientists® 2000–2017 | The Naked Scientists® and Naked Science® are registered trademarks created by Dr Chris Smith. Information presented on this website is the opinion of the individual contributors and does not reflect the general views of the administrators, editors, moderators, sponsors, Cambridge University or the public at large.