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. Non Life Sciences
  3. Physics, Astronomy & Cosmology
  4. Why don't an atom's electrons fall into the nucleus and stick to the protons?
« previous next »
  • Print
Pages: 1 ... 3 4 [5] 6 7 ... 21   Go Down

Why don't an atom's electrons fall into the nucleus and stick to the protons?

  • 415 Replies
  • 232776 Views
  • 5 Tags

0 Members and 1 Guest are viewing this topic.

Offline jeffreyH

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 6807
  • Activity:
    0%
  • Thanked: 174 times
  • The graviton sucks
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #80 on: 06/07/2014 16:15:20 »
Quote from: McKay on 06/07/2014 13:07:14
Well, here is something to read about this: http://www.wired.com/2014/06/the-new-quantum-reality
And in my mind, something like this provides a much better understanding of how things work - much better than: "an equation [or a principle] says so" ..

I vote de Broglie. He seems to have been sidelined and never made any further significant contributions to physics. It would be a testament to his foresight and give him more significance in the history of physics. I have for years thought quantum mechanics lacking clarity. No wonder quantum gravity has eluded physics for 100 years.
Logged
Even the most obstinately ignorant cannot avoid learning when in an environment that educates.
 



Offline jeffreyH

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 6807
  • Activity:
    0%
  • Thanked: 174 times
  • The graviton sucks
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #81 on: 06/07/2014 16:21:56 »
From the previously mentioned article.

"The experiments began a decade ago, when Yves Couder and colleagues at Paris Diderot University discovered that vibrating a silicon oil bath up and down at a particular frequency can induce a droplet to bounce along the surface. The droplet’s path, they found, was guided by the slanted contours of the liquid’s surface generated from the droplet’s own bounces — a mutual particle-wave interaction analogous to de Broglie’s pilot-wave concept."

In a modified form this describes gravity.
Logged
Even the most obstinately ignorant cannot avoid learning when in an environment that educates.
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 9198
  • Activity:
    71.5%
  • Thanked: 921 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #82 on: 07/07/2014 04:27:31 »
Quote from: jccc
If we can force electron and proton in hydrogen atoms to marry each other, the nucleus force field will break down and release all the energy stored
You can't really use an electron to release energy from a nucleus.
- For one thing, the electron very rarely interacts with the nucleus of an atom.
- And in those rare instances where an interaction does occur, much of the energy is carried away by the ghostly neutrino, which we can't capture as an energy source.

Combining two deuterium nuclei (or a dueterium & a tritium) to make a Helium nucleus does release a usable amount of energy.
- However, the wavelength of an electron is too long to draw the two nuclei together close enough for a nuclear reaction to occur at a usable rate.
- The wavelength of a negative muon is short enough to react deuterium nuclei together; unfortunately, the lifetime of the muon is too short to generate usable amounts of energy. (Or fortunately - if the muon were much better at catalysing a nuclear reaction between hydrogen nuclei, much of the hydrogen in the universe would already have fused to Helium...)
Logged
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 9198
  • Activity:
    71.5%
  • Thanked: 921 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #83 on: 08/07/2014 08:33:53 »
Quote
If energy is stored within nucleus force field, it should be negative charged in nature.

I don't think that conclusion is correct. The way I understand it:
  • Energy is stored in by electrical field in the nucleus, which exerts a force between the protons. But the electrical charge in the nucleus is positive, not negative.
  • Even more energy is stored by the strong nuclear field in the nucleus, which exerts a force between the protons and neutrons. But the strong nuclear force requires no electrical charge to function.
Logged
 

Online chiralSPO

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 3455
  • Activity:
    2%
  • Thanked: 435 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #84 on: 10/07/2014 23:33:06 »
How do you calculate "10^6 nucleus energy" out for e– + p+ → n ??

The equation E = keQ1Q2(1/rinitial–1/rfinal) gives no sensible answer if rfinal = 0 (as one might expect for the merger of the two point charges). Some theories predict charge separation within the neutron, but as far as I know, this has not been verified experimentally in any way. If I try values of about 1–2 fm as the final charge separation (approximate radius of a neutron) energy release is on the order of 2x10–13 J...  What was your calculation? What is nucleus energy? If the whole neutron were converted to energy (E = mc2), I calculate that as 1.5x10–10 J, which is not a factor of 106 different from anything... I am confused.

At any rate, we know experimentally that neutrons spontaneously decay exothermically (releasing energy) to produce electrons and protons, so unless the first law of thermodynamics doesn't apply here for some reason, I wouldn't expect the reverse reaction, your "neusion," to be exothermic. Am I missing something?
« Last Edit: 10/07/2014 23:36:31 by chiralSPO »
Logged
 



Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #85 on: 11/07/2014 02:17:59 »
I don't have calculation. I am thinking energy is stored within atoms, not nucleus. To release all the energy, we must break down nucleus force field to destroy the atoms.

Nucleus reactions only released a fiction of the energy stored within atoms. Because by products are still atoms.

Experiment should not be too hard, if I have a lab I'll be very busy.
Logged
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 9198
  • Activity:
    71.5%
  • Thanked: 921 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #86 on: 11/07/2014 12:36:24 »
Quote from: jccc
The nucleus force field is larger than atom radius, so that atoms can form matter.

The smallest atoms are Hydrogen (covalent radius around 30,000 femtometers) and Helium (radius 28,000 femtometers).

The nucleus is primarily held together by the strong nuclear force, which has a range of 1-3 femtometers. This is far less than the radius of even the smallest atom.

The distance which forms the chemical compounds in matter is determined by the quantum nature of electrons, not the nuclear force. (For gases, the Van Der Waals radius of a Hydrogen molecule is 120,000 femtometers.)

Jccc, please provide a hyperlink to the website which gave you the idea that the range of the nuclear force field is similar to the radius of an atom. (Note: "I just made it up" is not a good reference; experimental results are the best...)
« Last Edit: 11/07/2014 12:56:53 by evan_au »
Logged
 

Online chiralSPO

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 3455
  • Activity:
    2%
  • Thanked: 435 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #87 on: 11/07/2014 17:04:30 »
JCC, I think some of the confusion here has to do with trying to think classically about things on the atomic scale (and especially at the nuclear scale). Picturing protons and electrons as little charged balls that move like macroscopic balls will naturally lead to paradoxical and contradictory predictions.
Logged
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 9198
  • Activity:
    71.5%
  • Thanked: 921 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #88 on: 11/07/2014 20:46:20 »
The experimental result which first showed the distribution of charge within the atom was conducted by Geiger & Marsden in a 5-year period around 1910.

They fired alpha particles (positive charge) at a gold foil (electrically neutral). The results can be explained by classical replusion of electric charges. This experiment was not sensitive enough to measure the strong nuclear force, which occurs on much smaller scales.

Up to that time, there were a variety of models for charge within an atom; one of them (developed by J J Thomson) looks a bit like the Jccc model.

However, as a result of these experiments, an alternative model developed by Rutherford was accepted, where the positive charge is concentrated in a very small volume at the very center of the atom. (Rutherford was the director Geiger's lab).

The idea that "The nucleus force field is larger than atom radius" was discarded about 100 years ago, based on experimental evidence.

Science does need theories, but the most useful output of a theory is identifying a method to disprove that theory.

There have been many theories proposed, and anything you can think of has probably already been tried in some form by someone else - that's why they hand out Nobel prizes for genuinely new discoveries in certain fields. So, Jccc, it's useful to look at some of the history of science, so you don't resurrect theories which are already disproven. You are welcome to propose new theories, but identify them as a "maybe", not state them as a "fact"; do post them in the "New Theories" section, and try to suggest a way that will disprove your new theory.

That just leaves this thread with finding a simple explanation of the more complex quantum theory,  which was developed over the subsequent 40 years, partly to explain why the negative electrons don't collapse into the positive nucleus. I suggest you start your historical catch-up here: http://en.wikipedia.org/wiki/Quantum_mechanics
Logged
 



Offline Bill S

  • Naked Science Forum King!
  • ******
  • 3631
  • Activity:
    0%
  • Thanked: 108 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #89 on: 11/07/2014 22:47:45 »
 For some time I was puzzled by what seemed to be a reciprocity failure between electron jumps away from and towards the nucleus.  I reasoned that if an electron was attracted towards the nucleus, it should require more energy to move it away from the nucleus than towards it.  The conclusion I eventually reached was that as this was a quantum leap, the electron could not be said to be anywhere when it was not occupying an energy level.  If the electron could not be said to be anywhere, it could not be using or exchanging energy.  Thus it made no difference which way it was going.  The energy necessary to accomplish the jump would be the same.

I would appreciate comments on my reasoning, please.
Logged
There never was nothing.
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #90 on: 12/07/2014 01:39:00 »
Quote from: evan_au on 11/07/2014 20:46:20
The experimental result which first showed the distribution of charge within the atom was conducted by Geiger & Marsden in a 5-year period around 1910.

They fired alpha particles (positive charge) at a gold foil (electrically neutral). The results can be explained by classical replusion of electric charges. This experiment was not sensitive enough to measure the strong nuclear force, which occurs on much smaller scales.

Up to that time, there were a variety of models for charge within an atom; one of them (developed by J J Thomson) looks a bit like the Jccc model.

However, as a result of these experiments, an alternative model developed by Rutherford was accepted, where the positive charge is concentrated in a very small volume at the very center of the atom. (Rutherford was the director Geiger's lab).

The idea that "The nucleus force field is larger than atom radius" was discarded about 100 years ago, based on experimental evidence.

Science does need theories, but the most useful output of a theory is identifying a method to disprove that theory.

There have been many theories proposed, and anything you can think of has probably already been tried in some form by someone else - that's why they hand out Nobel prizes for genuinely new discoveries in certain fields. So, Jccc, it's useful to look at some of the history of science, so you don't resurrect theories which are already disproven. You are welcome to propose new theories, but identify them as a "maybe", not state them as a "fact"; do post them in the "New Theories" section, and try to suggest a way that will disprove your new theory.

That just leaves this thread with finding a simple explanation of the more complex quantum theory,  which was developed over the subsequent 40 years, partly to explain why the negative electrons don't collapse into the positive nucleus. I suggest you start your historical catch-up here: http://en.wikipedia.org/wiki/Quantum_mechanics

Thanks for the comment and link! I read that page few times before, wish I understand the math. Also read this http://en.wikipedia.org/wiki/J._J._Thomson. I am far behind every one here, pretty depressed.  It's all your fault.
Logged
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #91 on: 12/07/2014 03:15:39 »
Quote from: Bill S on 11/07/2014 22:47:45
For some time I was puzzled by what seemed to be a reciprocity failure between electron jumps away from and towards the nucleus.  I reasoned that if an electron was attracted towards the nucleus, it should require more energy to move it away from the nucleus than towards it.  The conclusion I eventually reached was that as this was a quantum leap, the electron could not be said to be anywhere when it was not occupying an energy level.  If the electron could not be said to be anywhere, it could not be using or exchanging energy.  Thus it made no difference which way it was going.  The energy necessary to accomplish the jump would be the same.

I would appreciate comments on my reasoning, please.


This might help, not QM stuff.

It takes more force to push in than pull away.
Logged
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #92 on: 12/07/2014 05:05:48 »
Quote from: evan_au

The idea that "The nucleus force field is larger than atom radius" was discarded about 100 years ago, based on experimental evidence.

Please explain the evidence, thanks.

Quote from: evan_au

Science does need theories, but the most useful output of a theory is identifying a method to disprove that theory.

How about as I suggested, beam high speed/energy electron into water, measure the energy used and the heat produced, they should be always the same according to present knowledge. If experiments show extra energy?
Logged
 



Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #93 on: 12/07/2014 15:02:06 »
2 H2o + 4e = o2 + E   

Oxygen atom nucleus has 8 protons, it attracts more energy into force field, the energy ball around it is denser than the energy ball around hydrogen atom nucleus.  Therefore, it takes higher energy electron to break down oxygen nucleus.

This give us control to only break down hydrogen atoms in the water. We don't want to break down oxygen atoms, it might produce new atoms and radiations.

Imagine a flash light type device which shoots high speed electron beams, point to a pond, dry it in minutes.

Point it to a watermelon, there is no more.

Do not let Pete have it.
« Last Edit: 12/07/2014 15:28:20 by jccc »
Logged
 

Online chiralSPO

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 3455
  • Activity:
    2%
  • Thanked: 435 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #94 on: 12/07/2014 16:24:11 »
Quote from: jccc on 12/07/2014 03:04:11
Quote from: evan_au on 11/07/2014 12:36:24
Quote from: jccc
The nucleus force field is larger than atom radius, so that atoms can form matter.

The smallest atoms are Hydrogen (covalent radius around 30,000 femtometers) and Helium (radius 28,000 femtometers).

The nucleus is primarily held together by the strong nuclear force, which has a range of 1-3 femtometers. This is far less than the radius of even the smallest atom.

The distance which forms the chemical compounds in matter is determined by the quantum nature of electrons, not the nuclear force. (For gases, the Van Der Waals radius of a Hydrogen molecule is 120,000 femtometers.)

Jccc, please provide a hyperlink to the website which gave you the idea that the range of the nuclear force field is similar to the radius of an atom. (Note: "I just made it up" is not a good reference; experimental results are the best...)
I remember we been discussing the possibility to pull the moon closer by charging it. We all agree that electrostatic force do work at long distance.

From F=kq1q2/r^2, also showed force between charged particles is always there even in long distance.

I said the nucleus force field is bigger than atom radius, means the positive charges within the nucleus produces a force field that is beyond atom radius. We can charge electron into neutral matter shows nucleus force attracts electron even out side the atom.

So what's wrong with this concept? The nucleus force field is larger than atom radius, so that atoms can form matter.

In your opinion, how big is nucleus force field? Or proton force field in a hydrogen atom?

It is widely accepted that the electrostatic force acts over long distances. I don't think anyone on this thread disputes that. When it was mentioned that the "nuclear force" exerts no significant effect at even reasonably small distances, what was meant was that the "strong force" which holds the positively charged nucleus together only acts over very, very short distances (femtometer scale)... This strong force is entirely different in nature and mechanism from the electrostatic force.

I am probably wrong here, but my intuition on this is that the strong force is related to an exchange energy of the quarks between the nucleons of the nucleus, so the effect decays exponentially with distance (e–k*r, where k is some constant; analogous to tunneling or exchanging electrons) in addition to the 1/r^2 law which arises from the fact that it spreads out in 3 dimensions. Any thoughts on this from the physicists out there? (this is just a chemist's hand-waving answer that allows me to sleep at night...)
Logged
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #95 on: 14/07/2014 00:28:24 »
Quote from: jccc on 12/07/2014 15:02:06
2 H2o + 4e = o2 + E   

Oxygen atom nucleus has 8 protons, it attracts more energy into force field, the energy ball around it is denser than the energy ball around hydrogen atom nucleus.  Therefore, it takes higher energy electron to break down oxygen nucleus.

This give us control to only break down hydrogen atoms in the water. We don't want to break down oxygen atoms, it might produce new atoms and radiations.


Any thoughts on this?

I think electron is not as easy to accelerate/energize as proton, maybe beam protons into negative charged water, hoping some head on action to happen.

The net reaction we want is p + e = E. Assume all mass converted.

Never thought I will dream such a small dream, thanks for this palace!

Our future is not in the stars but in the stardusts.
« Last Edit: 14/07/2014 00:48:23 by jccc »
Logged
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #96 on: 14/07/2014 02:32:57 »
Quote from: jccc on 14/07/2014 00:28:24
Quote from: jccc on 12/07/2014 15:02:06
2 H2o + 4e = o2 + E   

Oxygen atom nucleus has 8 protons, it attracts more energy into force field, the energy ball around it is denser than the energy ball around hydrogen atom nucleus.  Therefore, it takes higher energy electron to break down oxygen nucleus.

This give us control to only break down hydrogen atoms in the water. We don't want to break down oxygen atoms, it might produce new atoms and radiations.


Any thoughts on this?

I think electron is not as easy to accelerate/energize as proton, maybe beam protons into negative charged water, hoping some head on action to happen.

The net reaction we want is p + e = E. Assume all mass converted.

Never thought I will dream such a small dream, thanks for this palace!

Our future is not in the stars but in the stardusts.

This is my proof, try it.

Put e on top of p, what do you see/get? 
Logged
 



Online chiralSPO

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 3455
  • Activity:
    2%
  • Thanked: 435 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #97 on: 14/07/2014 03:43:48 »
Quote from: jccc on 14/07/2014 00:28:24


The net reaction we want is p + e = E. Assume all mass converted.


Our future is not in the stars but in the stardusts.

Positrons and electrons will annihilate each other to release much energy. Protons and electrons will not convert. There are no positrons in water.
Logged
 

Offline jccc

  • Hero Member
  • *****
  • 990
  • Activity:
    0%
  • Thanked: 2 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #98 on: 14/07/2014 08:46:33 »
Quote from: chiralSPO on 14/07/2014 03:43:48

Protons and electrons will not convert.


Electrons and protons will not convert? Any proof?

Logically any opposite charges will interact.

The goal is to break down protons positive charge/force field to release stored energy.

It's like to break a bloom to release pressure air. Or cut a robber band to release bonding stuff.

The trigger can be other than electron, maybe laser beam or other particle.

This is just a theory to be tested, looks too good to be true for now.
Logged
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 9198
  • Activity:
    71.5%
  • Thanked: 921 times
    • View Profile
Re: Why don't an atom's electrons fall into the nucleus and stick to the protons?
« Reply #99 on: 14/07/2014 10:17:57 »
Quote
Electrons and protons will not convert [into Energy]? Any proof?

Proof: Electron+Proton=Hydrogen atom (or two of each will make a Hydrogen molecule, H2)

The Hydrogen atom 1H is stable, with a lifetime of at least tens of billions of years (ie much longer than Uranium - too long for us to measure in a laboratory).

So a proton & electron do not annihilate to release energy.
Quote
The goal is to break down protons positive charge/force field to release stored energy.
A Proton and an electron do interact (to form Hydrogen), and they do release energy, in the form of an ultraviolet photon from the Lyman Series.

The maximum energy released in this photon is 13.6 eV (electron Volts).

The energy remaining in the Hydrogen atom is around 940,000,000 eV.

So the interaction of a proton and an electron releases about 13.6/940,000,000 = 0.000001% of the energy in the interacting particles.

But you can't use this 13.6eV as a source of unlimited energy, as you must supply more energy than this to the equipment which rips the electron off the Hydrogen atom in the first place, and you can't convert ultraviolet photons into electricity with 100% efficiency.
Logged
 



  • Print
Pages: 1 ... 3 4 [5] 6 7 ... 21   Go Up
« previous next »
Tags: atoms  / protons  / electrons  / nucleus  / atomic structure 
 

Similar topics (5)

What is a "neutron bomb", and how does it differ from an "atom bomb"?

Started by georgeBoard Physics, Astronomy & Cosmology

Replies: 13
Views: 21302
Last post 05/02/2007 18:45:36
by Batroost
How much would 1 H atom, 2He atoms, 4 Li atoms, 8 Be atoms... weigh?

Started by chiralSPOBoard Chemistry

Replies: 8
Views: 5797
Last post 22/01/2018 15:44:17
by chiralSPO
Does the apple fall to the floor, or does the floor rise to meet the apple?

Started by chrisBoard Physics, Astronomy & Cosmology

Replies: 40
Views: 14299
Last post 09/02/2017 20:27:44
by yor_on
Can we say that we "fall through spacetime"?

Started by geordiefBoard Physics, Astronomy & Cosmology

Replies: 8
Views: 1291
Last post 31/10/2019 00:20:19
by geordief
Could an different animal, other then a human, "fall in love" with you?

Started by SimulatedBoard Plant Sciences, Zoology & Evolution

Replies: 34
Views: 18479
Last post 30/01/2008 15:12:56
by Vcoolspice
There was an error while thanking
Thanking...
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.2 seconds with 79 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.